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| author | Thomas Gleixner <tglx@linutronix.de> | 2020-06-11 20:02:46 +0200 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2020-06-11 20:02:46 +0200 |
| commit | 37d1a04b13a6d2fec91a6813fc034947a27db034 (patch) | |
| tree | c6a8d7d0df96a6eb1ddb53a12885761cb72e0e92 | |
| parent | 37f8173dd84936ea78000ed1cad24f8b18d48ebb (diff) | |
| parent | 97a9474aeb789183a1d0712e66a4283860279ac9 (diff) | |
| download | lwn-37d1a04b13a6d2fec91a6813fc034947a27db034.tar.gz lwn-37d1a04b13a6d2fec91a6813fc034947a27db034.zip | |
Rebase locking/kcsan to locking/urgent
Merge the state of the locking kcsan branch before the read/write_once()
and the atomics modifications got merged.
Squash the fallout of the rebase on top of the read/write once and atomic
fallback work into the merge. The history of the original branch is
preserved in tag locking-kcsan-2020-06-02.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
59 files changed, 4164 insertions, 582 deletions
diff --git a/Documentation/dev-tools/index.rst b/Documentation/dev-tools/index.rst index 09dee10d2592..f7809c7b1ba9 100644 --- a/Documentation/dev-tools/index.rst +++ b/Documentation/dev-tools/index.rst @@ -21,6 +21,7 @@ whole; patches welcome! kasan ubsan kmemleak + kcsan gdb-kernel-debugging kgdb kselftest diff --git a/Documentation/dev-tools/kcsan.rst b/Documentation/dev-tools/kcsan.rst new file mode 100644 index 000000000000..f4b5766f12cc --- /dev/null +++ b/Documentation/dev-tools/kcsan.rst @@ -0,0 +1,328 @@ +The Kernel Concurrency Sanitizer (KCSAN) +======================================== + +The Kernel Concurrency Sanitizer (KCSAN) is a dynamic race detector, which +relies on compile-time instrumentation, and uses a watchpoint-based sampling +approach to detect races. KCSAN's primary purpose is to detect `data races`_. + +Usage +----- + +KCSAN is supported in both GCC and Clang. With GCC it requires version 7.3.0 or +later. With Clang it requires version 7.0.0 or later. + +To enable KCSAN configure the kernel with:: + + CONFIG_KCSAN = y + +KCSAN provides several other configuration options to customize behaviour (see +the respective help text in ``lib/Kconfig.kcsan`` for more info). + +Error reports +~~~~~~~~~~~~~ + +A typical data race report looks like this:: + + ================================================================== + BUG: KCSAN: data-race in generic_permission / kernfs_refresh_inode + + write to 0xffff8fee4c40700c of 4 bytes by task 175 on cpu 4: + kernfs_refresh_inode+0x70/0x170 + kernfs_iop_permission+0x4f/0x90 + inode_permission+0x190/0x200 + link_path_walk.part.0+0x503/0x8e0 + path_lookupat.isra.0+0x69/0x4d0 + filename_lookup+0x136/0x280 + user_path_at_empty+0x47/0x60 + vfs_statx+0x9b/0x130 + __do_sys_newlstat+0x50/0xb0 + __x64_sys_newlstat+0x37/0x50 + do_syscall_64+0x85/0x260 + entry_SYSCALL_64_after_hwframe+0x44/0xa9 + + read to 0xffff8fee4c40700c of 4 bytes by task 166 on cpu 6: + generic_permission+0x5b/0x2a0 + kernfs_iop_permission+0x66/0x90 + inode_permission+0x190/0x200 + link_path_walk.part.0+0x503/0x8e0 + path_lookupat.isra.0+0x69/0x4d0 + filename_lookup+0x136/0x280 + user_path_at_empty+0x47/0x60 + do_faccessat+0x11a/0x390 + __x64_sys_access+0x3c/0x50 + do_syscall_64+0x85/0x260 + entry_SYSCALL_64_after_hwframe+0x44/0xa9 + + Reported by Kernel Concurrency Sanitizer on: + CPU: 6 PID: 166 Comm: systemd-journal Not tainted 5.3.0-rc7+ #1 + Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-1 04/01/2014 + ================================================================== + +The header of the report provides a short summary of the functions involved in +the race. It is followed by the access types and stack traces of the 2 threads +involved in the data race. + +The other less common type of data race report looks like this:: + + ================================================================== + BUG: KCSAN: data-race in e1000_clean_rx_irq+0x551/0xb10 + + race at unknown origin, with read to 0xffff933db8a2ae6c of 1 bytes by interrupt on cpu 0: + e1000_clean_rx_irq+0x551/0xb10 + e1000_clean+0x533/0xda0 + net_rx_action+0x329/0x900 + __do_softirq+0xdb/0x2db + irq_exit+0x9b/0xa0 + do_IRQ+0x9c/0xf0 + ret_from_intr+0x0/0x18 + default_idle+0x3f/0x220 + arch_cpu_idle+0x21/0x30 + do_idle+0x1df/0x230 + cpu_startup_entry+0x14/0x20 + rest_init+0xc5/0xcb + arch_call_rest_init+0x13/0x2b + start_kernel+0x6db/0x700 + + Reported by Kernel Concurrency Sanitizer on: + CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.3.0-rc7+ #2 + Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-1 04/01/2014 + ================================================================== + +This report is generated where it was not possible to determine the other +racing thread, but a race was inferred due to the data value of the watched +memory location having changed. These can occur either due to missing +instrumentation or e.g. DMA accesses. These reports will only be generated if +``CONFIG_KCSAN_REPORT_RACE_UNKNOWN_ORIGIN=y`` (selected by default). + +Selective analysis +~~~~~~~~~~~~~~~~~~ + +It may be desirable to disable data race detection for specific accesses, +functions, compilation units, or entire subsystems. For static blacklisting, +the below options are available: + +* KCSAN understands the ``data_race(expr)`` annotation, which tells KCSAN that + any data races due to accesses in ``expr`` should be ignored and resulting + behaviour when encountering a data race is deemed safe. + +* Disabling data race detection for entire functions can be accomplished by + using the function attribute ``__no_kcsan``:: + + __no_kcsan + void foo(void) { + ... + + To dynamically limit for which functions to generate reports, see the + `DebugFS interface`_ blacklist/whitelist feature. + + For ``__always_inline`` functions, replace ``__always_inline`` with + ``__no_kcsan_or_inline`` (which implies ``__always_inline``):: + + static __no_kcsan_or_inline void foo(void) { + ... + + Note: Older compiler versions (GCC < 9) also do not always honor the + ``__no_kcsan`` attribute on regular ``inline`` functions. If false positives + with these compilers cannot be tolerated, for small functions where + ``__always_inline`` would be appropriate, ``__no_kcsan_or_inline`` should be + preferred instead. + +* To disable data race detection for a particular compilation unit, add to the + ``Makefile``:: + + KCSAN_SANITIZE_file.o := n + +* To disable data race detection for all compilation units listed in a + ``Makefile``, add to the respective ``Makefile``:: + + KCSAN_SANITIZE := n + +Furthermore, it is possible to tell KCSAN to show or hide entire classes of +data races, depending on preferences. These can be changed via the following +Kconfig options: + +* ``CONFIG_KCSAN_REPORT_VALUE_CHANGE_ONLY``: If enabled and a conflicting write + is observed via a watchpoint, but the data value of the memory location was + observed to remain unchanged, do not report the data race. + +* ``CONFIG_KCSAN_ASSUME_PLAIN_WRITES_ATOMIC``: Assume that plain aligned writes + up to word size are atomic by default. Assumes that such writes are not + subject to unsafe compiler optimizations resulting in data races. The option + causes KCSAN to not report data races due to conflicts where the only plain + accesses are aligned writes up to word size. + +DebugFS interface +~~~~~~~~~~~~~~~~~ + +The file ``/sys/kernel/debug/kcsan`` provides the following interface: + +* Reading ``/sys/kernel/debug/kcsan`` returns various runtime statistics. + +* Writing ``on`` or ``off`` to ``/sys/kernel/debug/kcsan`` allows turning KCSAN + on or off, respectively. + +* Writing ``!some_func_name`` to ``/sys/kernel/debug/kcsan`` adds + ``some_func_name`` to the report filter list, which (by default) blacklists + reporting data races where either one of the top stackframes are a function + in the list. + +* Writing either ``blacklist`` or ``whitelist`` to ``/sys/kernel/debug/kcsan`` + changes the report filtering behaviour. For example, the blacklist feature + can be used to silence frequently occurring data races; the whitelist feature + can help with reproduction and testing of fixes. + +Tuning performance +~~~~~~~~~~~~~~~~~~ + +Core parameters that affect KCSAN's overall performance and bug detection +ability are exposed as kernel command-line arguments whose defaults can also be +changed via the corresponding Kconfig options. + +* ``kcsan.skip_watch`` (``CONFIG_KCSAN_SKIP_WATCH``): Number of per-CPU memory + operations to skip, before another watchpoint is set up. Setting up + watchpoints more frequently will result in the likelihood of races to be + observed to increase. This parameter has the most significant impact on + overall system performance and race detection ability. + +* ``kcsan.udelay_task`` (``CONFIG_KCSAN_UDELAY_TASK``): For tasks, the + microsecond delay to stall execution after a watchpoint has been set up. + Larger values result in the window in which we may observe a race to + increase. + +* ``kcsan.udelay_interrupt`` (``CONFIG_KCSAN_UDELAY_INTERRUPT``): For + interrupts, the microsecond delay to stall execution after a watchpoint has + been set up. Interrupts have tighter latency requirements, and their delay + should generally be smaller than the one chosen for tasks. + +They may be tweaked at runtime via ``/sys/module/kcsan/parameters/``. + +Data Races +---------- + +In an execution, two memory accesses form a *data race* if they *conflict*, +they happen concurrently in different threads, and at least one of them is a +*plain access*; they *conflict* if both access the same memory location, and at +least one is a write. For a more thorough discussion and definition, see `"Plain +Accesses and Data Races" in the LKMM`_. + +.. _"Plain Accesses and Data Races" in the LKMM: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/tools/memory-model/Documentation/explanation.txt#n1922 + +Relationship with the Linux-Kernel Memory Consistency Model (LKMM) +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +The LKMM defines the propagation and ordering rules of various memory +operations, which gives developers the ability to reason about concurrent code. +Ultimately this allows to determine the possible executions of concurrent code, +and if that code is free from data races. + +KCSAN is aware of *marked atomic operations* (``READ_ONCE``, ``WRITE_ONCE``, +``atomic_*``, etc.), but is oblivious of any ordering guarantees and simply +assumes that memory barriers are placed correctly. In other words, KCSAN +assumes that as long as a plain access is not observed to race with another +conflicting access, memory operations are correctly ordered. + +This means that KCSAN will not report *potential* data races due to missing +memory ordering. Developers should therefore carefully consider the required +memory ordering requirements that remain unchecked. If, however, missing +memory ordering (that is observable with a particular compiler and +architecture) leads to an observable data race (e.g. entering a critical +section erroneously), KCSAN would report the resulting data race. + +Race Detection Beyond Data Races +-------------------------------- + +For code with complex concurrency design, race-condition bugs may not always +manifest as data races. Race conditions occur if concurrently executing +operations result in unexpected system behaviour. On the other hand, data races +are defined at the C-language level. The following macros can be used to check +properties of concurrent code where bugs would not manifest as data races. + +.. kernel-doc:: include/linux/kcsan-checks.h + :functions: ASSERT_EXCLUSIVE_WRITER ASSERT_EXCLUSIVE_WRITER_SCOPED + ASSERT_EXCLUSIVE_ACCESS ASSERT_EXCLUSIVE_ACCESS_SCOPED + ASSERT_EXCLUSIVE_BITS + +Implementation Details +---------------------- + +KCSAN relies on observing that two accesses happen concurrently. Crucially, we +want to (a) increase the chances of observing races (especially for races that +manifest rarely), and (b) be able to actually observe them. We can accomplish +(a) by injecting various delays, and (b) by using address watchpoints (or +breakpoints). + +If we deliberately stall a memory access, while we have a watchpoint for its +address set up, and then observe the watchpoint to fire, two accesses to the +same address just raced. Using hardware watchpoints, this is the approach taken +in `DataCollider +<http://usenix.org/legacy/events/osdi10/tech/full_papers/Erickson.pdf>`_. +Unlike DataCollider, KCSAN does not use hardware watchpoints, but instead +relies on compiler instrumentation and "soft watchpoints". + +In KCSAN, watchpoints are implemented using an efficient encoding that stores +access type, size, and address in a long; the benefits of using "soft +watchpoints" are portability and greater flexibility. KCSAN then relies on the +compiler instrumenting plain accesses. For each instrumented plain access: + +1. Check if a matching watchpoint exists; if yes, and at least one access is a + write, then we encountered a racing access. + +2. Periodically, if no matching watchpoint exists, set up a watchpoint and + stall for a small randomized delay. + +3. Also check the data value before the delay, and re-check the data value + after delay; if the values mismatch, we infer a race of unknown origin. + +To detect data races between plain and marked accesses, KCSAN also annotates +marked accesses, but only to check if a watchpoint exists; i.e. KCSAN never +sets up a watchpoint on marked accesses. By never setting up watchpoints for +marked operations, if all accesses to a variable that is accessed concurrently +are properly marked, KCSAN will never trigger a watchpoint and therefore never +report the accesses. + +Key Properties +~~~~~~~~~~~~~~ + +1. **Memory Overhead:** The overall memory overhead is only a few MiB + depending on configuration. The current implementation uses a small array of + longs to encode watchpoint information, which is negligible. + +2. **Performance Overhead:** KCSAN's runtime aims to be minimal, using an + efficient watchpoint encoding that does not require acquiring any shared + locks in the fast-path. For kernel boot on a system with 8 CPUs: + + - 5.0x slow-down with the default KCSAN config; + - 2.8x slow-down from runtime fast-path overhead only (set very large + ``KCSAN_SKIP_WATCH`` and unset ``KCSAN_SKIP_WATCH_RANDOMIZE``). + +3. **Annotation Overheads:** Minimal annotations are required outside the KCSAN + runtime. As a result, maintenance overheads are minimal as the kernel + evolves. + +4. **Detects Racy Writes from Devices:** Due to checking data values upon + setting up watchpoints, racy writes from devices can also be detected. + +5. **Memory Ordering:** KCSAN is *not* explicitly aware of the LKMM's ordering + rules; this may result in missed data races (false negatives). + +6. **Analysis Accuracy:** For observed executions, due to using a sampling + strategy, the analysis is *unsound* (false negatives possible), but aims to + be complete (no false positives). + +Alternatives Considered +----------------------- + +An alternative data race detection approach for the kernel can be found in the +`Kernel Thread Sanitizer (KTSAN) <https://github.com/google/ktsan/wiki>`_. +KTSAN is a happens-before data race detector, which explicitly establishes the +happens-before order between memory operations, which can then be used to +determine data races as defined in `Data Races`_. + +To build a correct happens-before relation, KTSAN must be aware of all ordering +rules of the LKMM and synchronization primitives. Unfortunately, any omission +leads to large numbers of false positives, which is especially detrimental in +the context of the kernel which includes numerous custom synchronization +mechanisms. To track the happens-before relation, KTSAN's implementation +requires metadata for each memory location (shadow memory), which for each page +corresponds to 4 pages of shadow memory, and can translate into overhead of +tens of GiB on a large system. diff --git a/MAINTAINERS b/MAINTAINERS index 9b4e836543a3..aea6fda02845 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -9305,6 +9305,17 @@ F: Documentation/kbuild/kconfig* F: scripts/Kconfig.include F: scripts/kconfig/ +KCSAN +M: Marco Elver <elver@google.com> +R: Dmitry Vyukov <dvyukov@google.com> +L: kasan-dev@googlegroups.com +S: Maintained +F: Documentation/dev-tools/kcsan.rst +F: include/linux/kcsan*.h +F: kernel/kcsan/ +F: lib/Kconfig.kcsan +F: scripts/Makefile.kcsan + KDUMP M: Dave Young <dyoung@redhat.com> M: Baoquan He <bhe@redhat.com> @@ -531,7 +531,7 @@ export KBUILD_HOSTCXXFLAGS KBUILD_HOSTLDFLAGS KBUILD_HOSTLDLIBS LDFLAGS_MODULE export KBUILD_CPPFLAGS NOSTDINC_FLAGS LINUXINCLUDE OBJCOPYFLAGS KBUILD_LDFLAGS export KBUILD_CFLAGS CFLAGS_KERNEL CFLAGS_MODULE -export CFLAGS_KASAN CFLAGS_KASAN_NOSANITIZE CFLAGS_UBSAN +export CFLAGS_KASAN CFLAGS_KASAN_NOSANITIZE CFLAGS_UBSAN CFLAGS_KCSAN export KBUILD_AFLAGS AFLAGS_KERNEL AFLAGS_MODULE export KBUILD_AFLAGS_MODULE KBUILD_CFLAGS_MODULE KBUILD_LDFLAGS_MODULE export KBUILD_AFLAGS_KERNEL KBUILD_CFLAGS_KERNEL @@ -965,6 +965,7 @@ endif include scripts/Makefile.kasan include scripts/Makefile.extrawarn include scripts/Makefile.ubsan +include scripts/Makefile.kcsan # Add user supplied CPPFLAGS, AFLAGS and CFLAGS as the last assignments KBUILD_CPPFLAGS += $(KCPPFLAGS) diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 10dae8b96ed5..6ad579c7d4cd 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -233,6 +233,7 @@ config X86 select THREAD_INFO_IN_TASK select USER_STACKTRACE_SUPPORT select VIRT_TO_BUS + select HAVE_ARCH_KCSAN if X86_64 select X86_FEATURE_NAMES if PROC_FS select PROC_PID_ARCH_STATUS if PROC_FS imply IMA_SECURE_AND_OR_TRUSTED_BOOT if EFI diff --git a/arch/x86/boot/Makefile b/arch/x86/boot/Makefile index 4c5355684321..fe605205b4ce 100644 --- a/arch/x86/boot/Makefile +++ b/arch/x86/boot/Makefile @@ -9,7 +9,9 @@ # Changed by many, many contributors over the years. # +# Sanitizer runtimes are unavailable and cannot be linked for early boot code. KASAN_SANITIZE := n +KCSAN_SANITIZE := n OBJECT_FILES_NON_STANDARD := y # Kernel does not boot with kcov instrumentation here. diff --git a/arch/x86/boot/compressed/Makefile b/arch/x86/boot/compressed/Makefile index 5f7c262bcc99..7619742f91c9 100644 --- a/arch/x86/boot/compressed/Makefile +++ b/arch/x86/boot/compressed/Makefile @@ -17,7 +17,9 @@ # (see scripts/Makefile.lib size_append) # compressed vmlinux.bin.all + u32 size of vmlinux.bin.all +# Sanitizer runtimes are unavailable and cannot be linked for early boot code. KASAN_SANITIZE := n +KCSAN_SANITIZE := n OBJECT_FILES_NON_STANDARD := y # Prevents link failures: __sanitizer_cov_trace_pc() is not linked in. diff --git a/arch/x86/entry/vdso/Makefile b/arch/x86/entry/vdso/Makefile index 54e03ab26ff3..04e65f0698f6 100644 --- a/arch/x86/entry/vdso/Makefile +++ b/arch/x86/entry/vdso/Makefile @@ -10,8 +10,11 @@ ARCH_REL_TYPE_ABS += R_386_GLOB_DAT|R_386_JMP_SLOT|R_386_RELATIVE include $(srctree)/lib/vdso/Makefile KBUILD_CFLAGS += $(DISABLE_LTO) + +# Sanitizer runtimes are unavailable and cannot be linked here. KASAN_SANITIZE := n UBSAN_SANITIZE := n +KCSAN_SANITIZE := n OBJECT_FILES_NON_STANDARD := y # Prevents link failures: __sanitizer_cov_trace_pc() is not linked in. @@ -29,6 +32,9 @@ vobjs32-y += vdso32/vclock_gettime.o # files to link into kernel obj-y += vma.o +KASAN_SANITIZE_vma.o := y +UBSAN_SANITIZE_vma.o := y +KCSAN_SANITIZE_vma.o := y OBJECT_FILES_NON_STANDARD_vma.o := n # vDSO images to build diff --git a/arch/x86/include/asm/bitops.h b/arch/x86/include/asm/bitops.h index 0367efdc5b7a..35460fef39b8 100644 --- a/arch/x86/include/asm/bitops.h +++ b/arch/x86/include/asm/bitops.h @@ -201,8 +201,12 @@ arch_test_and_change_bit(long nr, volatile unsigned long *addr) return GEN_BINARY_RMWcc(LOCK_PREFIX __ASM_SIZE(btc), *addr, c, "Ir", nr); } -static __always_inline bool constant_test_bit(long nr, const volatile unsigned long *addr) +static __no_kcsan_or_inline bool constant_test_bit(long nr, const volatile unsigned long *addr) { + /* + * Because this is a plain access, we need to disable KCSAN here to + * avoid double instrumentation via instrumented bitops. + */ return ((1UL << (nr & (BITS_PER_LONG-1))) & (addr[nr >> _BITOPS_LONG_SHIFT])) != 0; } diff --git a/arch/x86/kernel/Makefile b/arch/x86/kernel/Makefile index 8ef4369a4f06..e77261db2391 100644 --- a/arch/x86/kernel/Makefile +++ b/arch/x86/kernel/Makefile @@ -28,6 +28,10 @@ KASAN_SANITIZE_dumpstack_$(BITS).o := n KASAN_SANITIZE_stacktrace.o := n KASAN_SANITIZE_paravirt.o := n +# With some compiler versions the generated code results in boot hangs, caused +# by several compilation units. To be safe, disable all instrumentation. +KCSAN_SANITIZE := n + OBJECT_FILES_NON_STANDARD_test_nx.o := y OBJECT_FILES_NON_STANDARD_paravirt_patch.o := y diff --git a/arch/x86/kernel/cpu/Makefile b/arch/x86/kernel/cpu/Makefile index 7dc4ad68eb41..dba6a83bc349 100644 --- a/arch/x86/kernel/cpu/Makefile +++ b/arch/x86/kernel/cpu/Makefile @@ -13,6 +13,9 @@ endif KCOV_INSTRUMENT_common.o := n KCOV_INSTRUMENT_perf_event.o := n +# As above, instrumenting secondary CPU boot code causes boot hangs. +KCSAN_SANITIZE_common.o := n + # Make sure load_percpu_segment has no stackprotector nostackp := $(call cc-option, -fno-stack-protector) CFLAGS_common.o := $(nostackp) diff --git a/arch/x86/kernel/e820.c b/arch/x86/kernel/e820.c index 4d13c57f370a..983cd53ed4c9 100644 --- a/arch/x86/kernel/e820.c +++ b/arch/x86/kernel/e820.c @@ -991,7 +991,15 @@ void __init e820__reserve_setup_data(void) while (pa_data) { data = early_memremap(pa_data, sizeof(*data)); e820__range_update(pa_data, sizeof(*data)+data->len, E820_TYPE_RAM, E820_TYPE_RESERVED_KERN); - e820__range_update_kexec(pa_data, sizeof(*data)+data->len, E820_TYPE_RAM, E820_TYPE_RESERVED_KERN); + + /* + * SETUP_EFI is supplied by kexec and does not need to be + * reserved. + */ + if (data->type != SETUP_EFI) + e820__range_update_kexec(pa_data, + sizeof(*data) + data->len, + E820_TYPE_RAM, E820_TYPE_RESERVED_KERN); if (data->type == SETUP_INDIRECT && ((struct setup_indirect *)data->data)->type != SETUP_INDIRECT) { diff --git a/arch/x86/lib/Makefile b/arch/x86/lib/Makefile index 5246db42de45..6110bce7237b 100644 --- a/arch/x86/lib/Makefile +++ b/arch/x86/lib/Makefile @@ -6,10 +6,19 @@ # Produces uninteresting flaky coverage. KCOV_INSTRUMENT_delay.o := n +# KCSAN uses udelay for introducing watchpoint delay; avoid recursion. +KCSAN_SANITIZE_delay.o := n +ifdef CONFIG_KCSAN +# In case KCSAN+lockdep+ftrace are enabled, disable ftrace for delay.o to avoid +# lockdep -> [other libs] -> KCSAN -> udelay -> ftrace -> lockdep recursion. +CFLAGS_REMOVE_delay.o = $(CC_FLAGS_FTRACE) +endif + # Early boot use of cmdline; don't instrument it ifdef CONFIG_AMD_MEM_ENCRYPT KCOV_INSTRUMENT_cmdline.o := n KASAN_SANITIZE_cmdline.o := n +KCSAN_SANITIZE_cmdline.o := n ifdef CONFIG_FUNCTION_TRACER CFLAGS_REMOVE_cmdline.o = -pg diff --git a/arch/x86/mm/Makefile b/arch/x86/mm/Makefile index 98f7c6fa2eaa..f7fd0e868c9c 100644 --- a/arch/x86/mm/Makefile +++ b/arch/x86/mm/Makefile @@ -7,6 +7,10 @@ KCOV_INSTRUMENT_mem_encrypt_identity.o := n KASAN_SANITIZE_mem_encrypt.o := n KASAN_SANITIZE_mem_encrypt_identity.o := n +# Disable KCSAN entirely, because otherwise we get warnings that some functions +# reference __initdata sections. +KCSAN_SANITIZE := n + ifdef CONFIG_FUNCTION_TRACER CFLAGS_REMOVE_mem_encrypt.o = -pg CFLAGS_REMOVE_mem_encrypt_identity.o = -pg diff --git a/arch/x86/purgatory/.gitignore b/arch/x86/purgatory/.gitignore new file mode 100644 index 000000000000..d2be1500671d --- /dev/null +++ b/arch/x86/purgatory/.gitignore @@ -0,0 +1 @@ +purgatory.chk diff --git a/arch/x86/purgatory/Makefile b/arch/x86/purgatory/Makefile index fb4ee5444379..b04e6e72a592 100644 --- a/arch/x86/purgatory/Makefile +++ b/arch/x86/purgatory/Makefile @@ -14,10 +14,18 @@ $(obj)/sha256.o: $(srctree)/lib/crypto/sha256.c FORCE CFLAGS_sha256.o := -D__DISABLE_EXPORTS -LDFLAGS_purgatory.ro := -e purgatory_start -r --no-undefined -nostdlib -z nodefaultlib -targets += purgatory.ro - +# When linking purgatory.ro with -r unresolved symbols are not checked, +# also link a purgatory.chk binary without -r to check for unresolved symbols. +PURGATORY_LDFLAGS := -e purgatory_start -nostdlib -z nodefaultlib +LDFLAGS_purgatory.ro := -r $(PURGATORY_LDFLAGS) +LDFLAGS_purgatory.chk := $(PURGATORY_LDFLAGS) +targets += purgatory.ro purgatory.chk + +# Sanitizer, etc. runtimes are unavailable and cannot be linked here. +GCOV_PROFILE := n KASAN_SANITIZE := n +UBSAN_SANITIZE := n +KCSAN_SANITIZE := n KCOV_INSTRUMENT := n # These are adjustments to the compiler flags used for objects that @@ -25,7 +33,7 @@ KCOV_INSTRUMENT := n PURGATORY_CFLAGS_REMOVE := -mcmodel=kernel PURGATORY_CFLAGS := -mcmodel=large -ffreestanding -fno-zero-initialized-in-bss -PURGATORY_CFLAGS += $(DISABLE_STACKLEAK_PLUGIN) +PURGATORY_CFLAGS += $(DISABLE_STACKLEAK_PLUGIN) -DDISABLE_BRANCH_PROFILING # Default KBUILD_CFLAGS can have -pg option set when FTRACE is enabled. That # in turn leaves some undefined symbols like __fentry__ in purgatory and not @@ -58,12 +66,15 @@ CFLAGS_string.o += $(PURGATORY_CFLAGS) $(obj)/purgatory.ro: $(PURGATORY_OBJS) FORCE $(call if_changed,ld) +$(obj)/purgatory.chk: $(obj)/purgatory.ro FORCE + $(call if_changed,ld) + targets += kexec-purgatory.c quiet_cmd_bin2c = BIN2C $@ cmd_bin2c = $(objtree)/scripts/bin2c kexec_purgatory < $< > $@ -$(obj)/kexec-purgatory.c: $(obj)/purgatory.ro FORCE +$(obj)/kexec-purgatory.c: $(obj)/purgatory.ro $(obj)/purgatory.chk FORCE $(call if_changed,bin2c) obj-$(CONFIG_KEXEC_FILE) += kexec-purgatory.o diff --git a/arch/x86/realmode/Makefile b/arch/x86/realmode/Makefile index 682c895753d9..6b1f3a4eeb44 100644 --- a/arch/x86/realmode/Makefile +++ b/arch/x86/realmode/Makefile @@ -6,7 +6,10 @@ # for more details. # # + +# Sanitizer runtimes are unavailable and cannot be linked here. KASAN_SANITIZE := n +KCSAN_SANITIZE := n OBJECT_FILES_NON_STANDARD := y subdir- := rm diff --git a/arch/x86/realmode/rm/Makefile b/arch/x86/realmode/rm/Makefile index b11ec5d8f8ac..83f1b6a56449 100644 --- a/arch/x86/realmode/rm/Makefile +++ b/arch/x86/realmode/rm/Makefile @@ -6,7 +6,10 @@ # for more details. # # + +# Sanitizer runtimes are unavailable and cannot be linked here. KASAN_SANITIZE := n +KCSAN_SANITIZE := n OBJECT_FILES_NON_STANDARD := y # Prevents link failures: __sanitizer_cov_trace_pc() is not linked in. diff --git a/drivers/firmware/efi/libstub/Makefile b/drivers/firmware/efi/libstub/Makefile index cce4a7436052..75daaf20374e 100644 --- a/drivers/firmware/efi/libstub/Makefile +++ b/drivers/firmware/efi/libstub/Makefile @@ -37,7 +37,9 @@ KBUILD_CFLAGS := $(cflags-y) -Os -DDISABLE_BRANCH_PROFILING \ KBUILD_CFLAGS := $(filter-out $(CC_FLAGS_SCS), $(KBUILD_CFLAGS)) GCOV_PROFILE := n +# Sanitizer runtimes are unavailable and cannot be linked here. KASAN_SANITIZE := n +KCSAN_SANITIZE := n UBSAN_SANITIZE := n OBJECT_FILES_NON_STANDARD := y diff --git a/include/asm-generic/atomic-instrumented.h b/include/asm-generic/atomic-instrumented.h index e8730c6b9fe2..379986e40159 100644 --- a/include/asm-generic/atomic-instrumented.h +++ b/include/asm-generic/atomic-instrumented.h @@ -18,1623 +18,1624 @@ #define _ASM_GENERIC_ATOMIC_INSTRUMENTED_H #include <linux/build_bug.h> -#include <linux/kasan-checks.h> +#include <linux/compiler.h> +#include <linux/instrumented.h> -static inline int +static __always_inline int atomic_read(const atomic_t *v) { - kasan_check_read(v, sizeof(*v)); + instrument_atomic_read(v, sizeof(*v)); return arch_atomic_read(v); } #define atomic_read atomic_read #if defined(arch_atomic_read_acquire) -static inline int +static __always_inline int atomic_read_acquire(const atomic_t *v) { - kasan_check_read(v, sizeof(*v)); + instrument_atomic_read(v, sizeof(*v)); return arch_atomic_read_acquire(v); } #define atomic_read_acquire atomic_read_acquire #endif -static inline void +static __always_inline void atomic_set(atomic_t *v, int i) { - kasan_check_write(v, sizeof(*v)); + instrument_atomic_write(v, sizeof(*v)); arch_atomic_set(v, i); } #define atomic_set atomic_set #if defined(arch_atomic_set_release) -static inline void +static __always_inline void atomic_set_release(atomic_t *v, int i) { - kasan_check_write(v, sizeof(*v)); + instrument_atomic_write(v, sizeof(*v)); arch_atomic_set_release(v, i); } #define atomic_set_release atomic_set_release #endif -static inline void +static __always_inline void atomic_add(int i, atomic_t *v) { - kasan_check_write(v, sizeof(*v)); + instrument_atomic_write(v, sizeof(*v)); arch_atomic_add(i, v); } #define atomic_add atomic_add #if !defined(arch_atomic_add_return_relaxed) || defined(arch_atomic_add_return) -static inline int +static __always_inline int atomic_add_return(int i, atomic_t *v) { - kasan_check_write(v, sizeof(*v)); + instrument_atomic_write(v, sizeof(*v)); return arch_atomic_add_return(i, v); } #define atomic_add_return atomic_add_return #endif #if defined(arch_atomic_add_return_acquire) -static inline int +static __always_inline int atomic_add_return_acquire(int i, atomic_t *v) { - kasan_check_write(v, sizeof(*v)); + instrument_atomic_write(v, sizeof(*v)); return arch_atomic_add_return_acquire(i, v); } #define atomic_add_return_acquire atomic_add_return_acquire #endif #if defined(arch_atomic_add_return_release) -static inline int +static __always_inline int atomic_add_return_release(int i, atomic_t *v) { - kasan_check_write(v, sizeof(*v)); + instrument_atomic_write(v, sizeof(*v)); return arch_atomic_add_return_release(i, v); } #define atomic_add_return_release atomic_add_return_release #endif #if defined(arch_atomic_add_return_relaxed) -static inline int +static __always_inline int atomic_add_return_relaxed(int i, atomic_t *v) { - kasan_check_write(v, sizeof(*v)); + instrument_atomic_write(v, sizeof(*v)); return arch_atomic_add_return_relaxed(i, v); } #define atomic_add_return_relaxed atomic_add_return_relaxed #endif #if !defined(arch_atomic_fetch_add_relaxed) || defined(arch_atomic_fetch_add) -static inline int +static __always_inline int atomic_fetch_add(int i, atomic_t *v) { - kasan_check_write(v, sizeof(*v)); + instrument_atomic_write(v, sizeof(*v)); return arch_atomic_fetch_add(i, v); } #define atomic_fetch_add atomic_fetch_add #endif #if defined(arch_atomic_fetch_add_acquire) -static inline int +static __always_inline int atomic_fetch_add_acquire(int i, atomic_t *v) { - kasan_check_write(v, sizeof(*v)); + instrument_atomic_write(v, sizeof(*v)); return arch_atomic_fetch_add_acquire(i, v); } #define atomic_fetch_add_acquire atomic_fetch_add_acquire #endif #if defined(arch_atomic_fetch_add_release) -static inline int +static __always_inline int atomic_fetch_add_release(int i, atomic_t *v) { - kasan_check_write(v, sizeof(*v)); + instrument_atomic_write(v, sizeof(*v)); return arch_atomic_fetch_add_release(i, v); } #define atomic_fetch_add_release atomic_fetch_add_release #endif #if defined(arch_atomic_fetch_add_relaxed) -static inline int +static __always_inline int atomic_fetch_add_relaxed(int i, atomic_t *v) { - kasan_check_write(v, sizeof(*v)); + instrument_atomic_write(v, sizeof(*v)); return arch_atomic_fetch_add_relaxed(i, v); } #define atomic_fetch_add_relaxed atomic_fetch_add_relaxed #endif -static inline void +static __always_inline void atomic_sub(int i, atomic_t *v) { - kasan_check_write(v, sizeof(*v)); + instrument_atomic_write(v, sizeof(*v)); arch_atomic_sub(i, v); } #define atomic_sub atomic_sub #if !defined(arch_atomic_sub_return_relaxed) || defined(arch_atomic_sub_return) -static inline int +static __always_inline int atomic_sub_return(int i, atomic_t *v) { - kasan_check_write(v, sizeof(*v)); + instrument_atomic_write(v, sizeof(*v)); return arch_atomic_sub_return(i, v); } #define atomic_sub_return atomic_sub_return #endif #if defined(arch_atomic_sub_return_acquire) -static inline int +static __always_inline int atomic_sub_return_acquire(int i, atomic_t *v) { - kasan_check_write(v, sizeof(*v)); + instrument_atomic_write(v, sizeof(*v)); return arch_atomic_sub_return_acquire(i, v); } #define atomic_sub_return_acquire atomic_sub_return_acquire #endif #if defined(arch_atomic_sub_return_release) -static inline int +static __always_inline int atomic_sub_return_release(int i, atomic_t *v) { - kasan_check_write(v, sizeof(*v)); + instrument_atomic_write(v, sizeof(*v)); return arch_atomic_sub_return_release(i, v); } #define atomic_sub_return_release atomic_sub_return_release #endif #if defined(arch_atomic_sub_return_relaxed) -static inline int +static __always_inline int atomic_sub_return_relaxed(int i, atomic_t *v) { - kasan_check_write(v, sizeof(*v)); + instrument_atomic_write(v, sizeof(*v)); return arch_atomic_sub_return_relaxed(i, v); } #define atomic_sub_return_relaxed atomic_sub_return_relaxed #endif #if !defined(arch_atomic_fetch_sub_relaxed) || defined(arch_atomic_fetch_sub) -static inline int +static __always_inline int atomic_fetch_sub(int i, atomic_t *v) { - kasan_check_write(v, sizeof(*v)); + instrument_atomic_write(v, sizeof(*v)); return arch_atomic_fetch_sub(i, v); } #define atomic_fetch_sub atomic_fetch_sub #endif #if defined(arch_atomic_fetch_sub_acquire) -static inline int +static __always_inline int atomic_fetch_sub_acquire(int i, atomic_t *v) { - kasan_check_write(v, sizeof(*v)); + instrument_atomic_write(v, sizeof(*v)); return arch_atomic_fetch_sub_acquire(i, v); } #define atomic_fetch_sub_acquire atomic_fetch_sub_acquire #endif #if defined(arch_atomic_fetch_sub_release) -static inline int +static __always_inline int atomic_fetch_sub_release(int i, atomic_t *v) { - kasan_check_write(v, sizeof(*v)); + instrument_atomic_write(v, sizeof(*v)); return arch_atomic_fetch_sub_release(i, v); } #define atomic_fetch_sub_release atomic_fetch_sub_release #endif #if defined(arch_atomic_fetch_sub_relaxed) -static inline int +static __always_inline int atomic_fetch_sub_relaxed(int i, atomic_t *v) { - kasan_check_write(v, sizeof(*v)); + instrument_atomic_write(v, sizeof(*v)); return arch_atomic_fetch_sub_relaxed(i, v); } #define atomic_fetch_sub_relaxed atomic_fetch_sub_relaxed #endif #if defined(arch_atomic_inc) -static inline void +static __always_inline void atomic_inc(atomic_t *v) { - kasan_check_write(v, sizeof(*v)); + instrument_atomic_write(v, sizeof(*v)); arch_atomic_inc(v); } #define atomic_inc atomic_inc #endif #if defined(arch_atomic_inc_return) -static inline int +static __always_inline int atomic_inc_return(atomic_t *v) { - kasan_check_write(v, sizeof(*v)); + instrument_atomic_write(v, sizeof(*v)); return arch_atomic_inc_return(v); } #define atomic_inc_return atomic_inc_return #endif #if defined(arch_atomic_inc_return_acquire) -static inline int +static __always_inline int atomic_inc_return_acquire(atomic_t *v) { - kasan_check_write(v, sizeof(*v)); + instrument_atomic_write(v, sizeof(*v)); return arch_atomic_inc_return_acquire(v); } #define atomic_inc_return_acquire atomic_inc_return_acquire #endif #if defined(arch_atomic_inc_return_release) -static inline int +static __always_inline int atomic_inc_return_release(atomic_t *v) { - kasan_check_write(v, sizeof(*v)); + instrument_atomic_write(v, sizeof(*v)); return arch_atomic_inc_return_release(v); } #define atomic_inc_return_release atomic_inc_return_release #endif #if defined(arch_atomic_inc_return_relaxed) -static inline int +static __always_inline int atomic_inc_return_relaxed(atomic_t *v) { - kasan_check_write(v, sizeof(*v)); + instrument_atomic_write(v, sizeof(*v)); return arch_atomic_inc_return_relaxed(v); } #define atomic_inc_return_relaxed atomic_inc_return_relaxed #endif #if defined(arch_atomic_fetch_inc) -static inline int +static __always_inline int atomic_fetch_inc(atomic_t *v) { - kasan_check_write(v, sizeof(*v)); + instrument_atomic_write(v, sizeof(*v)); return arch_atomic_fetch_inc(v); } #define atomic_fetch_inc atomic_fetch_inc #endif #if defined(arch_atomic_fetch_inc_acquire) -static inline int +static __always_inline int atomic_fetch_inc_acquire(atomic_t *v) { - kasan_check_write(v, sizeof(*v)); + instrument_atomic_write(v, sizeof(*v)); return arch_atomic_fetch_inc_acquire(v); } #define atomic_fetch_inc_acquire atomic_fetch_inc_acquire #endif #if defined(arch_atomic_fetch_inc_release) -static inline int +static __always_inline int atomic_fetch_inc_release(atomic_t *v) { - kasan_check_write(v, sizeof(*v)); + instrument_atomic_write(v, sizeof(*v)); return arch_atomic_fetch_inc_release(v); } #define atomic_fetch_inc_release atomic_fetch_inc_release #endif #if defined(arch_atomic_fetch_inc_relaxed) -static inline int +static __always_inline int atomic_fetch_inc_relaxed(atomic_t *v) { - kasan_check_write(v, sizeof(*v)); + instrument_atomic_write(v, sizeof(*v)); return arch_atomic_fetch_inc_relaxed(v); } #define atomic_fetch_inc_relaxed atomic_fetch_inc_relaxed #endif #if defined(arch_atomic_dec) -static inline void +static __always_inline void atomic_dec(atomic_t *v) { - kasan_check_write(v, sizeof(*v)); + instrument_atomic_write(v, sizeof(*v)); arch_atomic_dec(v); } #define atomic_dec atomic_dec #endif #if defined(arch_atomic_dec_return) -static inline int +static __always_inline int atomic_dec_return(atomic_t *v) { - kasan_check_write(v, sizeof(*v)); + instrument_atomic_write(v, sizeof(*v)); return arch_atomic_dec_return(v); } #define atomic_dec_return atomic_dec_return #endif #if defined(arch_atomic_dec_return_acquire) -static inline int +static __always_inline int atomic_dec_return_acquire(atomic_t *v) { - kasan_check_write(v, sizeof(*v)); + instrument_atomic_write(v, sizeof(*v)); return arch_atomic_dec_return_acquire(v); } #define atomic_dec_return_acquire atomic_dec_return_acquire #endif #if defined(arch_atomic_dec_return_release) -static inline int +static __always_inline int atomic_dec_return_release(atomic_t *v) { - kasan_check_write(v, sizeof(*v)); + instrument_atomic_write(v, sizeof(*v)); return arch_atomic_dec_return_release(v); } #define atomic_dec_return_release atomic_dec_return_release #endif #if defined(arch_atomic_dec_return_relaxed) -static inline int +static __always_inline int atomic_dec_return_relaxed(atomic_t *v) { - kasan_check_write(v, sizeof(*v)); + instrument_atomic_write(v, sizeof(*v)); return arch_atomic_dec_return_relaxed(v); } #define atomic_dec_return_relaxed atomic_dec_return_relaxed #endif #if defined(arch_atomic_fetch_dec) -static inline int +static __always_inline int atomic_fetch_dec(atomic_t *v) { - kasan_check_write(v, sizeof(*v)); + instrument_atomic_write(v, sizeof(*v)); return arch_atomic_fetch_dec(v); } #define atomic_fetch_dec atomic_fetch_dec #endif #if defined(arch_atomic_fetch_dec_acquire) -static inline int +static __always_inline int atomic_fetch_dec_acquire(atomic_t *v) { - kasan_check_write(v, sizeof(*v)); + instrument_atomic_write(v, sizeof(*v)); return arch_atomic_fetch_dec_acquire(v); } #define atomic_fetch_dec_acquire atomic_fetch_dec_acquire #endif #if defined(arch_atomic_fetch_dec_release) -static inline int +static __always_inline int atomic_fetch_dec_release(atomic_t *v) { - kasan_check_write(v, sizeof(*v)); + instrument_atomic_write(v, sizeof(*v)); return arch_atomic_fetch_dec_release(v); } #define atomic_fetch_dec_release atomic_fetch_dec_release #endif #if defined(arch_atomic_fetch_dec_relaxed) -static inline int +static __always_inline int atomic_fetch_dec_relaxed(atomic_t *v) { - kasan_check_write(v, sizeof(*v)); + instrument_atomic_write(v, sizeof(*v)); return arch_atomic_fetch_dec_relaxed(v); } #define atomic_fetch_dec_relaxed atomic_fetch_dec_relaxed #endif -static inline void +static __always_inline void atomic_and(int i, atomic_t *v) { - kasan_check_write(v, sizeof(*v)); + instrument_atomic_write(v, sizeof(*v)); arch_atomic_and(i, v); } #define atomic_and atomic_and #if !defined(arch_atomic_fetch_and_relaxed) || defined(arch_atomic_fetch_and) -static inline int +static __always_inline int atomic_fetch_and(int i, atomic_t *v) { - kasan_check_write(v, sizeof(*v)); + instrument_atomic_write(v, sizeof(*v)); return arch_atomic_fetch_and(i, v); } #define atomic_fetch_and atomic_fetch_and #endif #if defined(arch_atomic_fetch_and_acquire) -static inline int +static __always_inline int atomic_fetch_and_acquire(int i, atomic_t *v) { - kasan_check_write(v, sizeof(*v)); + instrument_atomic_write(v, sizeof(*v)); return arch_atomic_fetch_and_acquire(i, v); } #define atomic_fetch_and_acquire atomic_fetch_and_acquire #endif #if defined(arch_atomic_fetch_and_release) -static inline int +static __always_inline int atomic_fetch_and_release(int i, atomic_t *v) { - kasan_check_write(v, sizeof(*v)); + instrument_atomic_write(v, sizeof(*v)); return arch_atomic_fetch_and_release(i, v); } #define atomic_fetch_and_release atomic_fetch_and_release #endif #if defined(arch_atomic_fetch_and_relaxed) -static inline int +static __always_inline int atomic_fetch_and_relaxed(int i, atomic_t *v) { - kasan_check_write(v, sizeof(*v)); + instrument_atomic_write(v, sizeof(*v)); return arch_atomic_fetch_and_relaxed(i, v); } #define atomic_fetch_and_relaxed atomic_fetch_and_relaxed #endif #if defined(arch_atomic_andnot) -static inline void +static __always_inline void atomic_andnot(int i, atomic_t *v) { - kasan_check_write(v, sizeof(*v)); + instrument_atomic_write(v, sizeof(*v)); arch_atomic_andnot(i, v); } #define atomic_andnot atomic_andnot #endif #if defined(arch_atomic_fetch_andnot) -static inline int +static __always_inline int atomic_fetch_andnot(int i, atomic_t *v) { - kasan_check_write(v, sizeof(*v)); + instrument_atomic_write(v, sizeof(*v)); return arch_atomic_fetch_andnot(i, v); } #define atomic_fetch_andnot atomic_fetch_andnot #endif #if defined(arch_atomic_fetch_andnot_acquire) -static inline int +static __always_inline int atomic_fetch_andnot_acquire(int i, atomic_t *v) { - kasan_check_write(v, sizeof(*v)); + instrument_atomic_write(v, sizeof(*v)); return arch_atomic_fetch_andnot_acquire(i, v); } #define atomic_fetch_andnot_acquire atomic_fetch_andnot_acquire #endif #if defined(arch_atomic_fetch_andnot_release) -static inline int +static __always_inline int atomic_fetch_andnot_release(int i, atomic_t *v) { - kasan_check_write(v, sizeof(*v)); + instrument_atomic_write(v, sizeof(*v)); return arch_atomic_fetch_andnot_release(i, v); } #define atomic_fetch_andnot_release atomic_fetch_andnot_release #endif #if defined(arch_atomic_fetch_andnot_relaxed) -static inline int +static __always_inline int atomic_fetch_andnot_relaxed(int i, atomic_t *v) { - kasan_check_write(v, sizeof(*v)); + instrument_atomic_write(v, sizeof(*v)); return arch_atomic_fetch_andnot_relaxed(i, v); } #define atomic_fetch_andnot_relaxed atomic_fetch_andnot_relaxed #endif -static inline void +static __always_inline void atomic_or(int i, atomic_t *v) { - kasan_check_write(v, sizeof(*v)); + instrument_atomic_write(v, sizeof(*v)); arch_atomic_or(i, v); } #define atomic_or atomic_or #if !defined(arch_atomic_fetch_or_relaxed) || defined(arch_atomic_fetch_or) -static inline int +static __always_inline int atomic_fetch_or(int i, atomic_t *v) { - kasan_check_write(v, sizeof(*v)); + instrument_atomic_write(v, sizeof(*v)); return arch_atomic_fetch_or(i, v); } #define atomic_fetch_or atomic_fetch_or #endif #if defined(arch_atomic_fetch_or_acquire) -static inline int +static __always_inline int atomic_fetch_or_acquire(int i, atomic_t *v) { - kasan_check_write(v, sizeof(*v)); + instrument_atomic_write(v, sizeof(*v)); return arch_atomic_fetch_or_acquire(i, v); } #define atomic_fetch_or_acquire atomic_fetch_or_acquire #endif #if defined(arch_atomic_fetch_or_release) -static inline int +static __always_inline int atomic_fetch_or_release(int i, atomic_t *v) { - kasan_check_write(v, sizeof(*v)); + instrument_atomic_write(v, sizeof(*v)); return arch_atomic_fetch_or_release(i, v); } #define atomic_fetch_or_release atomic_fetch_or_release #endif #if defined(arch_atomic_fetch_or_relaxed) -static inline int +static __always_inline int atomic_fetch_or_relaxed(int i, atomic_t *v) { - kasan_check_write(v, sizeof(*v)); + instrument_atomic_write(v, sizeof(*v)); return arch_atomic_fetch_or_relaxed(i, v); } #define atomic_fetch_or_relaxed atomic_fetch_or_relaxed #endif -static inline void +static __always_inline void atomic_xor(int i, atomic_t *v) { - kasan_check_write(v, sizeof(*v)); + instrument_atomic_write(v, sizeof(*v)); arch_atomic_xor(i, v); } #define atomic_xor atomic_xor #if !defined(arch_atomic_fetch_xor_relaxed) || defined(arch_atomic_fetch_xor) -static inline int +static __always_inline int atomic_fetch_xor(int i, atomic_t *v) { - kasan_check_write(v, sizeof(*v)); + instrument_atomic_write(v, sizeof(*v)); return arch_atomic_fetch_xor(i, v); } #define atomic_fetch_xor atomic_fetch_xor #endif #if defined(arch_atomic_fetch_xor_acquire) -static inline int +static __always_inline int atomic_fetch_xor_acquire(int i, atomic_t *v) { - kasan_check_write(v, sizeof(*v)); + instrument_atomic_write(v, sizeof(*v)); return arch_atomic_fetch_xor_acquire(i, v); } #define atomic_fetch_xor_acquire atomic_fetch_xor_acquire #endif #if defined(arch_atomic_fetch_xor_release) -static inline int +static __always_inline int atomic_fetch_xor_release(int i, atomic_t *v) { - kasan_check_write(v, sizeof(*v)); + instrument_atomic_write(v, sizeof(*v)); return arch_atomic_fetch_xor_release(i, v); } #define atomic_fetch_xor_release atomic_fetch_xor_release #endif #if defined(arch_atomic_fetch_xor_relaxed) -static inline int +static __always_inline int atomic_fetch_xor_relaxed(int i, atomic_t *v) { - kasan_check_write(v, sizeof(*v)); + instrument_atomic_write(v, sizeof(*v)); return arch_atomic_fetch_xor_relaxed(i, v); } #define atomic_fetch_xor_relaxed atomic_fetch_xor_relaxed #endif #if !defined(arch_atomic_xchg_relaxed) || defined(arch_atomic_xchg) -static inline int +static __always_inline int atomic_xchg(atomic_t *v, int i) { - kasan_check_write(v, sizeof(*v)); + instrument_atomic_write(v, sizeof(*v)); return arch_atomic_xchg(v, i); } #define atomic_xchg atomic_xchg #endif #if defined(arch_atomic_xchg_acquire) -static inline int +static __always_inline int atomic_xchg_acquire(atomic_t *v, int i) { - kasan_check_write(v, sizeof(*v)); + instrument_atomic_write(v, sizeof(*v)); return arch_atomic_xchg_acquire(v, i); } #define atomic_xchg_acquire atomic_xchg_acquire #endif #if defined(arch_atomic_xchg_release) -static inline int +static __always_inline int atomic_xchg_release(atomic_t *v, int i) { - kasan_check_write(v, sizeof(*v)); + instrument_atomic_write(v, sizeof(*v)); return arch_atomic_xchg_release(v, i); } #define atomic_xchg_release atomic_xchg_release #endif #if defined(arch_atomic_xchg_relaxed) -static inline int +static __always_inline int atomic_xchg_relaxed(atomic_t *v, int i) { - kasan_check_write(v, sizeof(*v)); + instrument_atomic_write(v, sizeof(*v)); return arch_atomic_xchg_relaxed(v, i); } #define atomic_xchg_relaxed atomic_xchg_relaxed #endif #if !defined(arch_atomic_cmpxchg_relaxed) || defined(arch_atomic_cmpxchg) -static inline int +static __always_inline int atomic_cmpxchg(atomic_t *v, int old, int new) { - kasan_check_write(v, sizeof(*v)); + instrument_atomic_write(v, sizeof(*v)); return arch_atomic_cmpxchg(v, old, new); } #define atomic_cmpxchg atomic_cmpxchg #endif #if defined(arch_atomic_cmpxchg_acquire) -static inline int +static __always_inline int atomic_cmpxchg_acquire(atomic_t *v, int old, int new) { - kasan_check_write(v, sizeof(*v)); + instrument_atomic_write(v, sizeof(*v)); return arch_atomic_cmpxchg_acquire(v, old, new); } #define atomic_cmpxchg_acquire atomic_cmpxchg_acquire #endif #if defined(arch_atomic_cmpxchg_release) -static inline int +static __always_inline int atomic_cmpxchg_release(atomic_t *v, int old, int new) { - kasan_check_write(v, sizeof(*v)); + instrument_atomic_write(v, sizeof(*v)); return arch_atomic_cmpxchg_release(v, old, new); } #define atomic_cmpxchg_release atomic_cmpxchg_release #endif #if defined(arch_atomic_cmpxchg_relaxed) -static inline int +static __always_inline int atomic_cmpxchg_relaxed(atomic_t *v, int old, int new) { - kasan_check_write(v, sizeof(*v)); + instrument_atomic_write(v, sizeof(*v)); return arch_atomic_cmpxchg_relaxed(v, old, new); } #define atomic_cmpxchg_relaxed atomic_cmpxchg_relaxed #endif #if defined(arch_atomic_try_cmpxchg) -static inline bool +static __always_inline bool atomic_try_cmpxchg(atomic_t *v, int *old, int new) { - kasan_check_write(v, sizeof(*v)); - kasan_check_write(old, sizeof(*old)); + instrument_atomic_write(v, sizeof(*v)); + instrument_atomic_write(old, sizeof(*old)); return arch_atomic_try_cmpxchg(v, old, new); } #define atomic_try_cmpxchg atomic_try_cmpxchg #endif #if defined(arch_atomic_try_cmpxchg_acquire) -static inline bool +static __always_inline bool atomic_try_cmpxchg_acquire(atomic_t *v, int *old, int new) { - kasan_check_write(v, sizeof(*v)); - kasan_check_write(old, sizeof(*old)); + instrument_atomic_write(v, sizeof(*v)); + instrument_atomic_write(old, sizeof(*old)); return arch_atomic_try_cmpxchg_acquire(v, old, new); } #define atomic_try_cmpxchg_acquire atomic_try_cmpxchg_acquire #endif #if defined(arch_atomic_try_cmpxchg_release) -static inline bool +static __always_inline bool atomic_try_cmpxchg_release(atomic_t *v, int *old, int new) { - kasan_check_write(v, sizeof(*v)); - kasan_check_write(old, sizeof(*old)); + instrument_atomic_write(v, sizeof(*v)); + instrument_atomic_write(old, sizeof(*old)); return arch_atomic_try_cmpxchg_release(v, old, new); } #define atomic_try_cmpxchg_release atomic_try_cmpxchg_release #endif #if defined(arch_atomic_try_cmpxchg_relaxed) -static inline bool +static __always_inline bool atomic_try_cmpxchg_relaxed(atomic_t *v, int *old, int new) { - kasan_check_write(v, sizeof(*v)); - kasan_check_write(old, sizeof(*old)); + instrument_atomic_write(v, sizeof(*v)); + instrument_atomic_write(old, sizeof(*old)); return arch_atomic_try_cmpxchg_relaxed(v, old, new); } #define atomic_try_cmpxchg_relaxed atomic_try_cmpxchg_relaxed #endif #if defined(arch_atomic_sub_and_test) -static inline bool +static __always_inline bool atomic_sub_and_test(int i, atomic_t *v) { - kasan_check_write(v, sizeof(*v)); + instrument_atomic_write(v, sizeof(*v)); return arch_atomic_sub_and_test(i, v); } #define atomic_sub_and_test atomic_sub_and_test #endif #if defined(arch_atomic_dec_and_test) -static inline bool +static __always_inline bool atomic_dec_and_test(atomic_t *v) { - kasan_check_write(v, sizeof(*v)); + instrument_atomic_write(v, sizeof(*v)); return arch_atomic_dec_and_test(v); } #define atomic_dec_and_test atomic_dec_and_test #endif #if defined(arch_atomic_inc_and_test) -static inline bool +static __always_inline bool atomic_inc_and_test(atomic_t *v) { - kasan_check_write(v, sizeof(*v)); + instrument_atomic_write(v, sizeof(*v)); return arch_atomic_inc_and_test(v); } #define atomic_inc_and_test atomic_inc_and_test #endif #if defined(arch_atomic_add_negative) -static inline bool +static __always_inline bool atomic_add_negative(int i, atomic_t *v) { - kasan_check_write(v, sizeof(*v)); + instrument_atomic_write(v, sizeof(*v)); return arch_atomic_add_negative(i, v); } #define atomic_add_negative atomic_add_negative #endif #if defined(arch_atomic_fetch_add_unless) -static inline int +static __always_inline int atomic_fetch_add_unless(atomic_t *v, int a, int u) { - kasan_check_write(v, sizeof(*v)); + instrument_atomic_write(v, sizeof(*v)); return arch_atomic_fetch_add_unless(v, a, u); } #define atomic_fetch_add_unless atomic_fetch_add_unless #endif #if defined(arch_atomic_add_unless) -static inline bool +static __always_inline bool atomic_add_unless(atomic_t *v, int a, int u) { - kasan_check_write(v, sizeof(*v)); + instrument_atomic_write(v, sizeof(*v)); return arch_atomic_add_unless(v, a, u); } #define atomic_add_unless atomic_add_unless #endif #if defined(arch_atomic_inc_not_zero) -static inline bool +static __always_inline bool atomic_inc_not_zero(atomic_t *v) { - kasan_check_write(v, sizeof(*v)); + instrument_atomic_write(v, sizeof(*v)); return arch_atomic_inc_not_zero(v); } #define atomic_inc_not_zero atomic_inc_not_zero #endif #if defined(arch_atomic_inc_unless_negative) -static inline bool +static __always_inline bool atomic_inc_unless_negative(atomic_t *v) { - kasan_check_write(v, sizeof(*v)); + instrument_atomic_write(v, sizeof(*v)); return arch_atomic_inc_unless_negative(v); } #define atomic_inc_unless_negative atomic_inc_unless_negative #endif #if defined(arch_atomic_dec_unless_positive) -static inline bool +static __always_inline bool atomic_dec_unless_positive(atomic_t *v) { - kasan_check_write(v, sizeof(*v)); + instrument_atomic_write(v, sizeof(*v)); return arch_atomic_dec_unless_positive(v); } #define atomic_dec_unless_positive atomic_dec_unless_positive #endif #if defined(arch_atomic_dec_if_positive) -static inline int +static __always_inline int atomic_dec_if_positive(atomic_t *v) { - kasan_check_write(v, sizeof(*v)); + instrument_atomic_write(v, sizeof(*v)); return arch_atomic_dec_if_positive(v); } #define atomic_dec_if_positive atomic_dec_if_positive #endif -static inline s64 +static __always_inline s64 atomic64_read(const atomic64_t *v) { - kasan_check_read(v, sizeof(*v)); + instrument_atomic_read(v, sizeof(*v)); return arch_atomic64_read(v); } #define atomic64_read atomic64_read #if defined(arch_atomic64_read_acquire) -static inline s64 +static __always_inline s64 atomic64_read_acquire(const atomic64_t *v) { - kasan_check_read(v, sizeof(*v)); + instrument_atomic_read(v, sizeof(*v)); return arch_atomic64_read_acquire(v); } #define atomic64_read_acquire atomic64_read_acquire #endif -static inline void +static __always_inline void atomic64_set(atomic64_t *v, s64 i) { - kasan_check_write(v, sizeof(*v)); + instrument_atomic_write(v, sizeof(*v)); arch_atomic64_set(v, i); } #define atomic64_set atomic64_set #if defined(arch_atomic64_set_release) -static inline void +static __always_inline void atomic64_set_release(atomic64_t *v, s64 i) { - kasan_check_write(v, sizeof(*v)); + instrument_atomic_write(v, sizeof(*v)); arch_atomic64_set_release(v, i); } #define atomic64_set_release atomic64_set_release #endif -static inline void +static __always_inline void atomic64_add(s64 i, atomic64_t *v) { - kasan_check_write(v, sizeof(*v)); + instrument_atomic_write(v, sizeof(*v)); arch_atomic64_add(i, v); } #define atomic64_add atomic64_add #if !defined(arch_atomic64_add_return_relaxed) || defined(arch_atomic64_add_return) -static inline s64 +static __always_inline s64 atomic64_add_return(s64 i, atomic64_t *v) { - kasan_check_write(v, sizeof(*v)); + instrument_atomic_write(v, sizeof(*v)); return arch_atomic64_add_return(i, v); } #define atomic64_add_return atomic64_add_return #endif #if defined(arch_atomic64_add_return_acquire) -static inline s64 +static __always_inline s64 atomic64_add_return_acquire(s64 i, atomic64_t *v) { - kasan_check_write(v, sizeof(*v)); + instrument_atomic_write(v, sizeof(*v)); return arch_atomic64_add_return_acquire(i, v); } #define atomic64_add_return_acquire atomic64_add_return_acquire #endif #if defined(arch_atomic64_add_return_release) -static inline s64 +static __always_inline s64 atomic64_add_return_release(s64 i, atomic64_t *v) { - kasan_check_write(v, sizeof(*v)); + instrument_atomic_write(v, sizeof(*v)); return arch_atomic64_add_return_release(i, v); } #define atomic64_add_return_release atomic64_add_return_release #endif #if defined(arch_atomic64_add_return_relaxed) -static inline s64 +static __always_inline s64 atomic64_add_return_relaxed(s64 i, atomic64_t *v) { - kasan_check_write(v, sizeof(*v)); + instrument_atomic_write(v, sizeof(*v)); return arch_atomic64_add_return_relaxed(i, v); } #define atomic64_add_return_relaxed atomic64_add_return_relaxed #endif #if !defined(arch_atomic64_fetch_add_relaxed) || defined(arch_atomic64_fetch_add) -static inline s64 +static __always_inline s64 atomic64_fetch_add(s64 i, atomic64_t *v) { - kasan_check_write(v, sizeof(*v)); + instrument_atomic_write(v, sizeof(*v)); return arch_atomic64_fetch_add(i, v); } #define atomic64_fetch_add atomic64_fetch_add #endif #if defined(arch_atomic64_fetch_add_acquire) -static inline s64 +static __always_inline s64 atomic64_fetch_add_acquire(s64 i, atomic64_t *v) { - kasan_check_write(v, sizeof(*v)); + instrument_atomic_write(v, sizeof(*v)); return arch_atomic64_fetch_add_acquire(i, v); } #define atomic64_fetch_add_acquire atomic64_fetch_add_acquire #endif #if defined(arch_atomic64_fetch_add_release) -static inline s64 +static __always_inline s64 atomic64_fetch_add_release(s64 i, atomic64_t *v) { - kasan_check_write(v, sizeof(*v)); + instrument_atomic_write(v, sizeof(*v)); return arch_atomic64_fetch_add_release(i, v); } #define atomic64_fetch_add_release atomic64_fetch_add_release #endif #if defined(arch_atomic64_fetch_add_relaxed) -static inline s64 +static __always_inline s64 atomic64_fetch_add_relaxed(s64 i, atomic64_t *v) { - kasan_check_write(v, sizeof(*v)); + instrument_atomic_write(v, sizeof(*v)); return arch_atomic64_fetch_add_relaxed(i, v); } #define atomic64_fetch_add_relaxed atomic64_fetch_add_relaxed #endif -static inline void +static __always_inline void atomic64_sub(s64 i, atomic64_t *v) { - kasan_check_write(v, sizeof(*v)); + instrument_atomic_write(v, sizeof(*v)); arch_atomic64_sub(i, v); } #define atomic64_sub atomic64_sub #if !defined(arch_atomic64_sub_return_relaxed) || defined(arch_atomic64_sub_return) -static inline s64 +static __always_inline s64 atomic64_sub_return(s64 i, atomic64_t *v) { - kasan_check_write(v, sizeof(*v)); + instrument_atomic_write(v, sizeof(*v)); return arch_atomic64_sub_return(i, v); } #define atomic64_sub_return atomic64_sub_return #endif #if defined(arch_atomic64_sub_return_acquire) -static inline s64 +static __always_inline s64 atomic64_sub_return_acquire(s64 i, atomic64_t *v) { - kasan_check_write(v, sizeof(*v)); + instrument_atomic_write(v, sizeof(*v)); return arch_atomic64_sub_return_acquire(i, v); } #define atomic64_sub_return_acquire atomic64_sub_return_acquire #endif #if defined(arch_atomic64_sub_return_release) -static inline s64 +static __always_inline s64 atomic64_sub_return_release(s64 i, atomic64_t *v) { - kasan_check_write(v, sizeof(*v)); + instrument_atomic_write(v, sizeof(*v)); return arch_atomic64_sub_return_release(i, v); } #define atomic64_sub_return_release atomic64_sub_return_release #endif #if defined(arch_atomic64_sub_return_relaxed) -static inline s64 +static __always_inline s64 atomic64_sub_return_relaxed(s64 i, atomic64_t *v) { - kasan_check_write(v, sizeof(*v)); + instrument_atomic_write(v, sizeof(*v)); return arch_atomic64_sub_return_relaxed(i, v); } #define atomic64_sub_return_relaxed atomic64_sub_return_relaxed #endif #if !defined(arch_atomic64_fetch_sub_relaxed) || defined(arch_atomic64_fetch_sub) -static inline s64 +static __always_inline s64 atomic64_fetch_sub(s64 i, atomic64_t *v) { - kasan_check_write(v, sizeof(*v)); + instrument_atomic_write(v, sizeof(*v)); return arch_atomic64_fetch_sub(i, v); } #define atomic64_fetch_sub atomic64_fetch_sub #endif #if defined(arch_atomic64_fetch_sub_acquire) -static inline s64 +static __always_inline s64 atomic64_fetch_sub_acquire(s64 i, atomic64_t *v) { - kasan_check_write(v, sizeof(*v)); + instrument_atomic_write(v, sizeof(*v)); return arch_atomic64_fetch_sub_acquire(i, v); } #define atomic64_fetch_sub_acquire atomic64_fetch_sub_acquire #endif #if defined(arch_atomic64_fetch_sub_release) -static inline s64 +static __always_inline s64 atomic64_fetch_sub_release(s64 i, atomic64_t *v) { - kasan_check_write(v, sizeof(*v)); + instrument_atomic_write(v, sizeof(*v)); return arch_atomic64_fetch_sub_release(i, v); } #define atomic64_fetch_sub_release atomic64_fetch_sub_release #endif #if defined(arch_atomic64_fetch_sub_relaxed) -static inline s64 +static __always_inline s64 atomic64_fetch_sub_relaxed(s64 i, atomic64_t *v) { - kasan_check_write(v, sizeof(*v)); + instrument_atomic_write(v, sizeof(*v)); return arch_atomic64_fetch_sub_relaxed(i, v); } #define atomic64_fetch_sub_relaxed atomic64_fetch_sub_relaxed #endif #if defined(arch_atomic64_inc) -static inline void +static __always_inline void atomic64_inc(atomic64_t *v) { - kasan_check_write(v, sizeof(*v)); + instrument_atomic_write(v, sizeof(*v)); arch_atomic64_inc(v); } #define atomic64_inc atomic64_inc #endif #if defined(arch_atomic64_inc_return) -static inline s64 +static __always_inline s64 atomic64_inc_return(atomic64_t *v) { - kasan_check_write(v, sizeof(*v)); + instrument_atomic_write(v, sizeof(*v)); return arch_atomic64_inc_return(v); } #define atomic64_inc_return atomic64_inc_return #endif #if defined(arch_atomic64_inc_return_acquire) -static inline s64 +static __always_inline s64 atomic64_inc_return_acquire(atomic64_t *v) { - kasan_check_write(v, sizeof(*v)); + instrument_atomic_write(v, sizeof(*v)); return arch_atomic64_inc_return_acquire(v); } #define atomic64_inc_return_acquire atomic64_inc_return_acquire #endif #if defined(arch_atomic64_inc_return_release) -static inline s64 +static __always_inline s64 atomic64_inc_return_release(atomic64_t *v) { - kasan_check_write(v, sizeof(*v)); + instrument_atomic_write(v, sizeof(*v)); return arch_atomic64_inc_return_release(v); } #define atomic64_inc_return_release atomic64_inc_return_release #endif #if defined(arch_atomic64_inc_return_relaxed) -static inline s64 +static __always_inline s64 atomic64_inc_return_relaxed(atomic64_t *v) { - kasan_check_write(v, sizeof(*v)); + instrument_atomic_write(v, sizeof(*v)); return arch_atomic64_inc_return_relaxed(v); } #define atomic64_inc_return_relaxed atomic64_inc_return_relaxed #endif #if defined(arch_atomic64_fetch_inc) -static inline s64 +static __always_inline s64 atomic64_fetch_inc(atomic64_t *v) { - kasan_check_write(v, sizeof(*v)); + instrument_atomic_write(v, sizeof(*v)); return arch_atomic64_fetch_inc(v); } #define atomic64_fetch_inc atomic64_fetch_inc #endif #if defined(arch_atomic64_fetch_inc_acquire) -static inline s64 +static __always_inline s64 atomic64_fetch_inc_acquire(atomic64_t *v) { - kasan_check_write(v, sizeof(*v)); + instrument_atomic_write(v, sizeof(*v)); return arch_atomic64_fetch_inc_acquire(v); } #define atomic64_fetch_inc_acquire atomic64_fetch_inc_acquire #endif #if defined(arch_atomic64_fetch_inc_release) -static inline s64 +static __always_inline s64 atomic64_fetch_inc_release(atomic64_t *v) { - kasan_check_write(v, sizeof(*v)); + instrument_atomic_write(v, sizeof(*v)); return arch_atomic64_fetch_inc_release(v); } #define atomic64_fetch_inc_release atomic64_fetch_inc_release #endif #if defined(arch_atomic64_fetch_inc_relaxed) -static inline s64 +static __always_inline s64 atomic64_fetch_inc_relaxed(atomic64_t *v) { - kasan_check_write(v, sizeof(*v)); + instrument_atomic_write(v, sizeof(*v)); return arch_atomic64_fetch_inc_relaxed(v); } #define atomic64_fetch_inc_relaxed atomic64_fetch_inc_relaxed #endif #if defined(arch_atomic64_dec) -static inline void +static __always_inline void atomic64_dec(atomic64_t *v) { - kasan_check_write(v, sizeof(*v)); + instrument_atomic_write(v, sizeof(*v)); arch_atomic64_dec(v); } #define atomic64_dec atomic64_dec #endif #if defined(arch_atomic64_dec_return) -static inline s64 +static __always_inline s64 atomic64_dec_return(atomic64_t *v) { - kasan_check_write(v, sizeof(*v)); + instrument_atomic_write(v, sizeof(*v)); return arch_atomic64_dec_return(v); } #define atomic64_dec_return atomic64_dec_return #endif #if defined(arch_atomic64_dec_return_acquire) -static inline s64 +static __always_inline s64 atomic64_dec_return_acquire(atomic64_t *v) { - kasan_check_write(v, sizeof(*v)); + instrument_atomic_write(v, sizeof(*v)); return arch_atomic64_dec_return_acquire(v); } #define atomic64_dec_return_acquire atomic64_dec_return_acquire #endif #if defined(arch_atomic64_dec_return_release) -static inline s64 +static __always_inline s64 atomic64_dec_return_release(atomic64_t *v) { - kasan_check_write(v, sizeof(*v)); + instrument_atomic_write(v, sizeof(*v)); return arch_atomic64_dec_return_release(v); } #define atomic64_dec_return_release atomic64_dec_return_release #endif #if defined(arch_atomic64_dec_return_relaxed) -static inline s64 +static __always_inline s64 atomic64_dec_return_relaxed(atomic64_t *v) { - kasan_check_write(v, sizeof(*v)); + instrument_atomic_write(v, sizeof(*v)); return arch_atomic64_dec_return_relaxed(v); } #define atomic64_dec_return_relaxed atomic64_dec_return_relaxed #endif #if defined(arch_atomic64_fetch_dec) -static inline s64 +static __always_inline s64 atomic64_fetch_dec(atomic64_t *v) { - kasan_check_write(v, sizeof(*v)); + instrument_atomic_write(v, sizeof(*v)); return arch_atomic64_fetch_dec(v); } #define atomic64_fetch_dec atomic64_fetch_dec #endif #if defined(arch_atomic64_fetch_dec_acquire) -static inline s64 +static __always_inline s64 atomic64_fetch_dec_acquire(atomic64_t *v) { - kasan_check_write(v, sizeof(*v)); + instrument_atomic_write(v, sizeof(*v)); return arch_atomic64_fetch_dec_acquire(v); } #define atomic64_fetch_dec_acquire atomic64_fetch_dec_acquire #endif #if defined(arch_atomic64_fetch_dec_release) -static inline s64 +static __always_inline s64 atomic64_fetch_dec_release(atomic64_t *v) { - kasan_check_write(v, sizeof(*v)); + instrument_atomic_write(v, sizeof(*v)); return arch_atomic64_fetch_dec_release(v); } #define atomic64_fetch_dec_release atomic64_fetch_dec_release #endif #if defined(arch_atomic64_fetch_dec_relaxed) -static inline s64 +static __always_inline s64 atomic64_fetch_dec_relaxed(atomic64_t *v) { - kasan_check_write(v, sizeof(*v)); + instrument_atomic_write(v, sizeof(*v)); return arch_atomic64_fetch_dec_relaxed(v); } #define atomic64_fetch_dec_relaxed atomic64_fetch_dec_relaxed #endif -static inline void +static __always_inline void atomic64_and(s64 i, atomic64_t *v) { - kasan_check_write(v, sizeof(*v)); + instrument_atomic_write(v, sizeof(*v)); arch_atomic64_and(i, v); } #define atomic64_and atomic64_and #if !defined(arch_atomic64_fetch_and_relaxed) || defined(arch_atomic64_fetch_and) -static inline s64 +static __always_inline s64 atomic64_fetch_and(s64 i, atomic64_t *v) { - kasan_check_write(v, sizeof(*v)); + instrument_atomic_write(v, sizeof(*v)); return arch_atomic64_fetch_and(i, v); } #define atomic64_fetch_and atomic64_fetch_and #endif #if defined(arch_atomic64_fetch_and_acquire) -static inline s64 +static __always_inline s64 atomic64_fetch_and_acquire(s64 i, atomic64_t *v) { - kasan_check_write(v, sizeof(*v)); + instrument_atomic_write(v, sizeof(*v)); return arch_atomic64_fetch_and_acquire(i, v); } #define atomic64_fetch_and_acquire atomic64_fetch_and_acquire #endif #if defined(arch_atomic64_fetch_and_release) -static inline s64 +static __always_inline s64 atomic64_fetch_and_release(s64 i, atomic64_t *v) { - kasan_check_write(v, sizeof(*v)); + instrument_atomic_write(v, sizeof(*v)); return arch_atomic64_fetch_and_release(i, v); } #define atomic64_fetch_and_release atomic64_fetch_and_release #endif #if defined(arch_atomic64_fetch_and_relaxed) -static inline s64 +static __always_inline s64 atomic64_fetch_and_relaxed(s64 i, atomic64_t *v) { - kasan_check_write(v, sizeof(*v)); + instrument_atomic_write(v, sizeof(*v)); return arch_atomic64_fetch_and_relaxed(i, v); } #define atomic64_fetch_and_relaxed atomic64_fetch_and_relaxed #endif #if defined(arch_atomic64_andnot) -static inline void +static __always_inline void atomic64_andnot(s64 i, atomic64_t *v) { - kasan_check_write(v, sizeof(*v)); + instrument_atomic_write(v, sizeof(*v)); arch_atomic64_andnot(i, v); } #define atomic64_andnot atomic64_andnot #endif #if defined(arch_atomic64_fetch_andnot) -static inline s64 +static __always_inline s64 atomic64_fetch_andnot(s64 i, atomic64_t *v) { - kasan_check_write(v, sizeof(*v)); + instrument_atomic_write(v, sizeof(*v)); return arch_atomic64_fetch_andnot(i, v); } #define atomic64_fetch_andnot atomic64_fetch_andnot #endif #if defined(arch_atomic64_fetch_andnot_acquire) -static inline s64 +static __always_inline s64 atomic64_fetch_andnot_acquire(s64 i, atomic64_t *v) { - kasan_check_write(v, sizeof(*v)); + instrument_atomic_write(v, sizeof(*v)); return arch_atomic64_fetch_andnot_acquire(i, v); } #define atomic64_fetch_andnot_acquire atomic64_fetch_andnot_acquire #endif #if defined(arch_atomic64_fetch_andnot_release) -static inline s64 +static __always_inline s64 atomic64_fetch_andnot_release(s64 i, atomic64_t *v) { - kasan_check_write(v, sizeof(*v)); + instrument_atomic_write(v, sizeof(*v)); return arch_atomic64_fetch_andnot_release(i, v); } #define atomic64_fetch_andnot_release atomic64_fetch_andnot_release #endif #if defined(arch_atomic64_fetch_andnot_relaxed) -static inline s64 +static __always_inline s64 atomic64_fetch_andnot_relaxed(s64 i, atomic64_t *v) { - kasan_check_write(v, sizeof(*v)); + instrument_atomic_write(v, sizeof(*v)); return arch_atomic64_fetch_andnot_relaxed(i, v); } #define atomic64_fetch_andnot_relaxed atomic64_fetch_andnot_relaxed #endif -static inline void +static __always_inline void atomic64_or(s64 i, atomic64_t *v) { - kasan_check_write(v, sizeof(*v)); + instrument_atomic_write(v, sizeof(*v)); arch_atomic64_or(i, v); } #define atomic64_or atomic64_or #if !defined(arch_atomic64_fetch_or_relaxed) || defined(arch_atomic64_fetch_or) -static inline s64 +static __always_inline s64 atomic64_fetch_or(s64 i, atomic64_t *v) { - kasan_check_write(v, sizeof(*v)); + instrument_atomic_write(v, sizeof(*v)); return arch_atomic64_fetch_or(i, v); } #define atomic64_fetch_or atomic64_fetch_or #endif #if defined(arch_atomic64_fetch_or_acquire) -static inline s64 +static __always_inline s64 atomic64_fetch_or_acquire(s64 i, atomic64_t *v) { - kasan_check_write(v, sizeof(*v)); + instrument_atomic_write(v, sizeof(*v)); return arch_atomic64_fetch_or_acquire(i, v); } #define atomic64_fetch_or_acquire atomic64_fetch_or_acquire #endif #if defined(arch_atomic64_fetch_or_release) -static inline s64 +static __always_inline s64 atomic64_fetch_or_release(s64 i, atomic64_t *v) { - kasan_check_write(v, sizeof(*v)); + instrument_atomic_write(v, sizeof(*v)); return arch_atomic64_fetch_or_release(i, v); } #define atomic64_fetch_or_release atomic64_fetch_or_release #endif #if defined(arch_atomic64_fetch_or_relaxed) -static inline s64 +static __always_inline s64 atomic64_fetch_or_relaxed(s64 i, atomic64_t *v) { - kasan_check_write(v, sizeof(*v)); + instrument_atomic_write(v, sizeof(*v)); return arch_atomic64_fetch_or_relaxed(i, v); } #define atomic64_fetch_or_relaxed atomic64_fetch_or_relaxed #endif -static inline void +static __always_inline void atomic64_xor(s64 i, atomic64_t *v) { - kasan_check_write(v, sizeof(*v)); + instrument_atomic_write(v, sizeof(*v)); arch_atomic64_xor(i, v); } #define atomic64_xor atomic64_xor #if !defined(arch_atomic64_fetch_xor_relaxed) || defined(arch_atomic64_fetch_xor) -static inline s64 +static __always_inline s64 atomic64_fetch_xor(s64 i, atomic64_t *v) { - kasan_check_write(v, sizeof(*v)); + instrument_atomic_write(v, sizeof(*v)); return arch_atomic64_fetch_xor(i, v); } #define atomic64_fetch_xor atomic64_fetch_xor #endif #if defined(arch_atomic64_fetch_xor_acquire) -static inline s64 +static __always_inline s64 atomic64_fetch_xor_acquire(s64 i, atomic64_t *v) { - kasan_check_write(v, sizeof(*v)); + instrument_atomic_write(v, sizeof(*v)); return arch_atomic64_fetch_xor_acquire(i, v); } #define atomic64_fetch_xor_acquire atomic64_fetch_xor_acquire #endif #if defined(arch_atomic64_fetch_xor_release) -static inline s64 +static __always_inline s64 atomic64_fetch_xor_release(s64 i, atomic64_t *v) { - kasan_check_write(v, sizeof(*v)); + instrument_atomic_write(v, sizeof(*v)); return arch_atomic64_fetch_xor_release(i, v); } #define atomic64_fetch_xor_release atomic64_fetch_xor_release #endif #if defined(arch_atomic64_fetch_xor_relaxed) -static inline s64 +static __always_inline s64 atomic64_fetch_xor_relaxed(s64 i, atomic64_t *v) { - kasan_check_write(v, sizeof(*v)); + instrument_atomic_write(v, sizeof(*v)); return arch_atomic64_fetch_xor_relaxed(i, v); } #define atomic64_fetch_xor_relaxed atomic64_fetch_xor_relaxed #endif #if !defined(arch_atomic64_xchg_relaxed) || defined(arch_atomic64_xchg) -static inline s64 +static __always_inline s64 atomic64_xchg(atomic64_t *v, s64 i) { - kasan_check_write(v, sizeof(*v)); + instrument_atomic_write(v, sizeof(*v)); return arch_atomic64_xchg(v, i); } #define atomic64_xchg atomic64_xchg #endif #if defined(arch_atomic64_xchg_acquire) -static inline s64 +static __always_inline s64 atomic64_xchg_acquire(atomic64_t *v, s64 i) { - kasan_check_write(v, sizeof(*v)); + instrument_atomic_write(v, sizeof(*v)); return arch_atomic64_xchg_acquire(v, i); } #define atomic64_xchg_acquire atomic64_xchg_acquire #endif #if defined(arch_atomic64_xchg_release) -static inline s64 +static __always_inline s64 atomic64_xchg_release(atomic64_t *v, s64 i) { - kasan_check_write(v, sizeof(*v)); + instrument_atomic_write(v, sizeof(*v)); return arch_atomic64_xchg_release(v, i); } #define atomic64_xchg_release atomic64_xchg_release #endif #if defined(arch_atomic64_xchg_relaxed) -static inline s64 +static __always_inline s64 atomic64_xchg_relaxed(atomic64_t *v, s64 i) { - kasan_check_write(v, sizeof(*v)); + instrument_atomic_write(v, sizeof(*v)); return arch_atomic64_xchg_relaxed(v, i); } #define atomic64_xchg_relaxed atomic64_xchg_relaxed #endif #if !defined(arch_atomic64_cmpxchg_relaxed) || defined(arch_atomic64_cmpxchg) -static inline s64 +static __always_inline s64 atomic64_cmpxchg(atomic64_t *v, s64 old, s64 new) { - kasan_check_write(v, sizeof(*v)); + instrument_atomic_write(v, sizeof(*v)); return arch_atomic64_cmpxchg(v, old, new); } #define atomic64_cmpxchg atomic64_cmpxchg #endif #if defined(arch_atomic64_cmpxchg_acquire) -static inline s64 +static __always_inline s64 atomic64_cmpxchg_acquire(atomic64_t *v, s64 old, s64 new) { - kasan_check_write(v, sizeof(*v)); + instrument_atomic_write(v, sizeof(*v)); return arch_atomic64_cmpxchg_acquire(v, old, new); } #define atomic64_cmpxchg_acquire atomic64_cmpxchg_acquire #endif #if defined(arch_atomic64_cmpxchg_release) -static inline s64 +static __always_inline s64 atomic64_cmpxchg_release(atomic64_t *v, s64 old, s64 new) { - kasan_check_write(v, sizeof(*v)); + instrument_atomic_write(v, sizeof(*v)); return arch_atomic64_cmpxchg_release(v, old, new); } #define atomic64_cmpxchg_release atomic64_cmpxchg_release #endif #if defined(arch_atomic64_cmpxchg_relaxed) -static inline s64 +static __always_inline s64 atomic64_cmpxchg_relaxed(atomic64_t *v, s64 old, s64 new) { - kasan_check_write(v, sizeof(*v)); + instrument_atomic_write(v, sizeof(*v)); return arch_atomic64_cmpxchg_relaxed(v, old, new); } #define atomic64_cmpxchg_relaxed atomic64_cmpxchg_relaxed #endif #if defined(arch_atomic64_try_cmpxchg) -static inline bool +static __always_inline bool atomic64_try_cmpxchg(atomic64_t *v, s64 *old, s64 new) { - kasan_check_write(v, sizeof(*v)); - kasan_check_write(old, sizeof(*old)); + instrument_atomic_write(v, sizeof(*v)); + instrument_atomic_write(old, sizeof(*old)); return arch_atomic64_try_cmpxchg(v, old, new); } #define atomic64_try_cmpxchg atomic64_try_cmpxchg #endif #if defined(arch_atomic64_try_cmpxchg_acquire) -static inline bool +static __always_inline bool atomic64_try_cmpxchg_acquire(atomic64_t *v, s64 *old, s64 new) { - kasan_check_write(v, sizeof(*v)); - kasan_check_write(old, sizeof(*old)); + instrument_atomic_write(v, sizeof(*v)); + instrument_atomic_write(old, sizeof(*old)); return arch_atomic64_try_cmpxchg_acquire(v, old, new); } #define atomic64_try_cmpxchg_acquire atomic64_try_cmpxchg_acquire #endif #if defined(arch_atomic64_try_cmpxchg_release) -static inline bool +static __always_inline bool atomic64_try_cmpxchg_release(atomic64_t *v, s64 *old, s64 new) { - kasan_check_write(v, sizeof(*v)); - kasan_check_write(old, sizeof(*old)); + instrument_atomic_write(v, sizeof(*v)); + instrument_atomic_write(old, sizeof(*old)); return arch_atomic64_try_cmpxchg_release(v, old, new); } #define atomic64_try_cmpxchg_release atomic64_try_cmpxchg_release #endif #if defined(arch_atomic64_try_cmpxchg_relaxed) -static inline bool +static __always_inline bool atomic64_try_cmpxchg_relaxed(atomic64_t *v, s64 *old, s64 new) { - kasan_check_write(v, sizeof(*v)); - kasan_check_write(old, sizeof(*old)); + instrument_atomic_write(v, sizeof(*v)); + instrument_atomic_write(old, sizeof(*old)); return arch_atomic64_try_cmpxchg_relaxed(v, old, new); } #define atomic64_try_cmpxchg_relaxed atomic64_try_cmpxchg_relaxed #endif #if defined(arch_atomic64_sub_and_test) -static inline bool +static __always_inline bool atomic64_sub_and_test(s64 i, atomic64_t *v) { - kasan_check_write(v, sizeof(*v)); + instrument_atomic_write(v, sizeof(*v)); return arch_atomic64_sub_and_test(i, v); } #define atomic64_sub_and_test atomic64_sub_and_test #endif #if defined(arch_atomic64_dec_and_test) -static inline bool +static __always_inline bool atomic64_dec_and_test(atomic64_t *v) { - kasan_check_write(v, sizeof(*v)); + instrument_atomic_write(v, sizeof(*v)); return arch_atomic64_dec_and_test(v); } #define atomic64_dec_and_test atomic64_dec_and_test #endif #if defined(arch_atomic64_inc_and_test) -static inline bool +static __always_inline bool atomic64_inc_and_test(atomic64_t *v) { - kasan_check_write(v, sizeof(*v)); + instrument_atomic_write(v, sizeof(*v)); return arch_atomic64_inc_and_test(v); } #define atomic64_inc_and_test atomic64_inc_and_test #endif #if defined(arch_atomic64_add_negative) -static inline bool +static __always_inline bool atomic64_add_negative(s64 i, atomic64_t *v) { - kasan_check_write(v, sizeof(*v)); + instrument_atomic_write(v, sizeof(*v)); return arch_atomic64_add_negative(i, v); } #define atomic64_add_negative atomic64_add_negative #endif #if defined(arch_atomic64_fetch_add_unless) -static inline s64 +static __always_inline s64 atomic64_fetch_add_unless(atomic64_t *v, s64 a, s64 u) { - kasan_check_write(v, sizeof(*v)); + instrument_atomic_write(v, sizeof(*v)); return arch_atomic64_fetch_add_unless(v, a, u); } #define atomic64_fetch_add_unless atomic64_fetch_add_unless #endif #if defined(arch_atomic64_add_unless) -static inline bool +static __always_inline bool atomic64_add_unless(atomic64_t *v, s64 a, s64 u) { - kasan_check_write(v, sizeof(*v)); + instrument_atomic_write(v, sizeof(*v)); return arch_atomic64_add_unless(v, a, u); } #define atomic64_add_unless atomic64_add_unless #endif #if defined(arch_atomic64_inc_not_zero) -static inline bool +static __always_inline bool atomic64_inc_not_zero(atomic64_t *v) { - kasan_check_write(v, sizeof(*v)); + instrument_atomic_write(v, sizeof(*v)); return arch_atomic64_inc_not_zero(v); } #define atomic64_inc_not_zero atomic64_inc_not_zero #endif #if defined(arch_atomic64_inc_unless_negative) -static inline bool +static __always_inline bool atomic64_inc_unless_negative(atomic64_t *v) { - kasan_check_write(v, sizeof(*v)); + instrument_atomic_write(v, sizeof(*v)); return arch_atomic64_inc_unless_negative(v); } #define atomic64_inc_unless_negative atomic64_inc_unless_negative #endif #if defined(arch_atomic64_dec_unless_positive) -static inline bool +static __always_inline bool atomic64_dec_unless_positive(atomic64_t *v) { - kasan_check_write(v, sizeof(*v)); + instrument_atomic_write(v, sizeof(*v)); return arch_atomic64_dec_unless_positive(v); } #define atomic64_dec_unless_positive atomic64_dec_unless_positive #endif #if defined(arch_atomic64_dec_if_positive) -static inline s64 +static __always_inline s64 atomic64_dec_if_positive(atomic64_t *v) { - kasan_check_write(v, sizeof(*v)); + instrument_atomic_write(v, sizeof(*v)); return arch_atomic64_dec_if_positive(v); } #define atomic64_dec_if_positive atomic64_dec_if_positive @@ -1644,7 +1645,7 @@ atomic64_dec_if_positive(atomic64_t *v) #define xchg(ptr, ...) \ ({ \ typeof(ptr) __ai_ptr = (ptr); \ - kasan_check_write(__ai_ptr, sizeof(*__ai_ptr)); \ + instrument_atomic_write(__ai_ptr, sizeof(*__ai_ptr)); \ arch_xchg(__ai_ptr, __VA_ARGS__); \ }) #endif @@ -1653,7 +1654,7 @@ atomic64_dec_if_positive(atomic64_t *v) #define xchg_acquire(ptr, ...) \ ({ \ typeof(ptr) __ai_ptr = (ptr); \ - kasan_check_write(__ai_ptr, sizeof(*__ai_ptr)); \ + instrument_atomic_write(__ai_ptr, sizeof(*__ai_ptr)); \ arch_xchg_acquire(__ai_ptr, __VA_ARGS__); \ }) #endif @@ -1662,7 +1663,7 @@ atomic64_dec_if_positive(atomic64_t *v) #define xchg_release(ptr, ...) \ ({ \ typeof(ptr) __ai_ptr = (ptr); \ - kasan_check_write(__ai_ptr, sizeof(*__ai_ptr)); \ + instrument_atomic_write(__ai_ptr, sizeof(*__ai_ptr)); \ arch_xchg_release(__ai_ptr, __VA_ARGS__); \ }) #endif @@ -1671,7 +1672,7 @@ atomic64_dec_if_positive(atomic64_t *v) #define xchg_relaxed(ptr, ...) \ ({ \ typeof(ptr) __ai_ptr = (ptr); \ - kasan_check_write(__ai_ptr, sizeof(*__ai_ptr)); \ + instrument_atomic_write(__ai_ptr, sizeof(*__ai_ptr)); \ arch_xchg_relaxed(__ai_ptr, __VA_ARGS__); \ }) #endif @@ -1680,7 +1681,7 @@ atomic64_dec_if_positive(atomic64_t *v) #define cmpxchg(ptr, ...) \ ({ \ typeof(ptr) __ai_ptr = (ptr); \ - kasan_check_write(__ai_ptr, sizeof(*__ai_ptr)); \ + instrument_atomic_write(__ai_ptr, sizeof(*__ai_ptr)); \ arch_cmpxchg(__ai_ptr, __VA_ARGS__); \ }) #endif @@ -1689,7 +1690,7 @@ atomic64_dec_if_positive(atomic64_t *v) #define cmpxchg_acquire(ptr, ...) \ ({ \ typeof(ptr) __ai_ptr = (ptr); \ - kasan_check_write(__ai_ptr, sizeof(*__ai_ptr)); \ + instrument_atomic_write(__ai_ptr, sizeof(*__ai_ptr)); \ arch_cmpxchg_acquire(__ai_ptr, __VA_ARGS__); \ }) #endif @@ -1698,7 +1699,7 @@ atomic64_dec_if_positive(atomic64_t *v) #define cmpxchg_release(ptr, ...) \ ({ \ typeof(ptr) __ai_ptr = (ptr); \ - kasan_check_write(__ai_ptr, sizeof(*__ai_ptr)); \ + instrument_atomic_write(__ai_ptr, sizeof(*__ai_ptr)); \ arch_cmpxchg_release(__ai_ptr, __VA_ARGS__); \ }) #endif @@ -1707,7 +1708,7 @@ atomic64_dec_if_positive(atomic64_t *v) #define cmpxchg_relaxed(ptr, ...) \ ({ \ typeof(ptr) __ai_ptr = (ptr); \ - kasan_check_write(__ai_ptr, sizeof(*__ai_ptr)); \ + instrument_atomic_write(__ai_ptr, sizeof(*__ai_ptr)); \ arch_cmpxchg_relaxed(__ai_ptr, __VA_ARGS__); \ }) #endif @@ -1716,7 +1717,7 @@ atomic64_dec_if_positive(atomic64_t *v) #define cmpxchg64(ptr, ...) \ ({ \ typeof(ptr) __ai_ptr = (ptr); \ - kasan_check_write(__ai_ptr, sizeof(*__ai_ptr)); \ + instrument_atomic_write(__ai_ptr, sizeof(*__ai_ptr)); \ arch_cmpxchg64(__ai_ptr, __VA_ARGS__); \ }) #endif @@ -1725,7 +1726,7 @@ atomic64_dec_if_positive(atomic64_t *v) #define cmpxchg64_acquire(ptr, ...) \ ({ \ typeof(ptr) __ai_ptr = (ptr); \ - kasan_check_write(__ai_ptr, sizeof(*__ai_ptr)); \ + instrument_atomic_write(__ai_ptr, sizeof(*__ai_ptr)); \ arch_cmpxchg64_acquire(__ai_ptr, __VA_ARGS__); \ }) #endif @@ -1734,7 +1735,7 @@ atomic64_dec_if_positive(atomic64_t *v) #define cmpxchg64_release(ptr, ...) \ ({ \ typeof(ptr) __ai_ptr = (ptr); \ - kasan_check_write(__ai_ptr, sizeof(*__ai_ptr)); \ + instrument_atomic_write(__ai_ptr, sizeof(*__ai_ptr)); \ arch_cmpxchg64_release(__ai_ptr, __VA_ARGS__); \ }) #endif @@ -1743,7 +1744,7 @@ atomic64_dec_if_positive(atomic64_t *v) #define cmpxchg64_relaxed(ptr, ...) \ ({ \ typeof(ptr) __ai_ptr = (ptr); \ - kasan_check_write(__ai_ptr, sizeof(*__ai_ptr)); \ + instrument_atomic_write(__ai_ptr, sizeof(*__ai_ptr)); \ arch_cmpxchg64_relaxed(__ai_ptr, __VA_ARGS__); \ }) #endif @@ -1751,28 +1752,28 @@ atomic64_dec_if_positive(atomic64_t *v) #define cmpxchg_local(ptr, ...) \ ({ \ typeof(ptr) __ai_ptr = (ptr); \ - kasan_check_write(__ai_ptr, sizeof(*__ai_ptr)); \ + instrument_atomic_write(__ai_ptr, sizeof(*__ai_ptr)); \ arch_cmpxchg_local(__ai_ptr, __VA_ARGS__); \ }) #define cmpxchg64_local(ptr, ...) \ ({ \ typeof(ptr) __ai_ptr = (ptr); \ - kasan_check_write(__ai_ptr, sizeof(*__ai_ptr)); \ + instrument_atomic_write(__ai_ptr, sizeof(*__ai_ptr)); \ arch_cmpxchg64_local(__ai_ptr, __VA_ARGS__); \ }) #define sync_cmpxchg(ptr, ...) \ ({ \ typeof(ptr) __ai_ptr = (ptr); \ - kasan_check_write(__ai_ptr, sizeof(*__ai_ptr)); \ + instrument_atomic_write(__ai_ptr, sizeof(*__ai_ptr)); \ arch_sync_cmpxchg(__ai_ptr, __VA_ARGS__); \ }) #define cmpxchg_double(ptr, ...) \ ({ \ typeof(ptr) __ai_ptr = (ptr); \ - kasan_check_write(__ai_ptr, 2 * sizeof(*__ai_ptr)); \ + instrument_atomic_write(__ai_ptr, 2 * sizeof(*__ai_ptr)); \ arch_cmpxchg_double(__ai_ptr, __VA_ARGS__); \ }) @@ -1780,9 +1781,9 @@ atomic64_dec_if_positive(atomic64_t *v) #define cmpxchg_double_local(ptr, ...) \ ({ \ typeof(ptr) __ai_ptr = (ptr); \ - kasan_check_write(__ai_ptr, 2 * sizeof(*__ai_ptr)); \ + instrument_atomic_write(__ai_ptr, 2 * sizeof(*__ai_ptr)); \ arch_cmpxchg_double_local(__ai_ptr, __VA_ARGS__); \ }) #endif /* _ASM_GENERIC_ATOMIC_INSTRUMENTED_H */ -// b29b625d5de9280f680e42c7be859b55b15e5f6a +// 89bf97f3a7509b740845e51ddf31055b48a81f40 diff --git a/include/asm-generic/atomic-long.h b/include/asm-generic/atomic-long.h index 881c7e27af28..073cf40f431b 100644 --- a/include/asm-generic/atomic-long.h +++ b/include/asm-generic/atomic-long.h @@ -6,6 +6,7 @@ #ifndef _ASM_GENERIC_ATOMIC_LONG_H #define _ASM_GENERIC_ATOMIC_LONG_H +#include <linux/compiler.h> #include <asm/types.h> #ifdef CONFIG_64BIT @@ -22,493 +23,493 @@ typedef atomic_t atomic_long_t; #ifdef CONFIG_64BIT -static inline long +static __always_inline long atomic_long_read(const atomic_long_t *v) { return atomic64_read(v); } -static inline long +static __always_inline long atomic_long_read_acquire(const atomic_long_t *v) { return atomic64_read_acquire(v); } -static inline void +static __always_inline void atomic_long_set(atomic_long_t *v, long i) { atomic64_set(v, i); } -static inline void +static __always_inline void atomic_long_set_release(atomic_long_t *v, long i) { atomic64_set_release(v, i); } -static inline void +static __always_inline void atomic_long_add(long i, atomic_long_t *v) { atomic64_add(i, v); } -static inline long +static __always_inline long atomic_long_add_return(long i, atomic_long_t *v) { return atomic64_add_return(i, v); } -static inline long +static __always_inline long atomic_long_add_return_acquire(long i, atomic_long_t *v) { return atomic64_add_return_acquire(i, v); } -static inline long +static __always_inline long atomic_long_add_return_release(long i, atomic_long_t *v) { return atomic64_add_return_release(i, v); } -static inline long +static __always_inline long atomic_long_add_return_relaxed(long i, atomic_long_t *v) { return atomic64_add_return_relaxed(i, v); } -static inline long +static __always_inline long atomic_long_fetch_add(long i, atomic_long_t *v) { return atomic64_fetch_add(i, v); } -static inline long +static __always_inline long atomic_long_fetch_add_acquire(long i, atomic_long_t *v) { return atomic64_fetch_add_acquire(i, v); } -static inline long +static __always_inline long atomic_long_fetch_add_release(long i, atomic_long_t *v) { return atomic64_fetch_add_release(i, v); } -static inline long +static __always_inline long atomic_long_fetch_add_relaxed(long i, atomic_long_t *v) { return atomic64_fetch_add_relaxed(i, v); } -static inline void +static __always_inline void atomic_long_sub(long i, atomic_long_t *v) { atomic64_sub(i, v); } -static inline long +static __always_inline long atomic_long_sub_return(long i, atomic_long_t *v) { return atomic64_sub_return(i, v); } -static inline long +static __always_inline long atomic_long_sub_return_acquire(long i, atomic_long_t *v) { return atomic64_sub_return_acquire(i, v); } -static inline long +static __always_inline long atomic_long_sub_return_release(long i, atomic_long_t *v) { return atomic64_sub_return_release(i, v); } -static inline long +static __always_inline long atomic_long_sub_return_relaxed(long i, atomic_long_t *v) { return atomic64_sub_return_relaxed(i, v); } -static inline long +static __always_inline long atomic_long_fetch_sub(long i, atomic_long_t *v) { return atomic64_fetch_sub(i, v); } -static inline long +static __always_inline long atomic_long_fetch_sub_acquire(long i, atomic_long_t *v) { return atomic64_fetch_sub_acquire(i, v); } -static inline long +static __always_inline long atomic_long_fetch_sub_release(long i, atomic_long_t *v) { return atomic64_fetch_sub_release(i, v); } -static inline long +static __always_inline long atomic_long_fetch_sub_relaxed(long i, atomic_long_t *v) { return atomic64_fetch_sub_relaxed(i, v); } -static inline void +static __always_inline void atomic_long_inc(atomic_long_t *v) { atomic64_inc(v); } -static inline long +static __always_inline long atomic_long_inc_return(atomic_long_t *v) { return atomic64_inc_return(v); } -static inline long +static __always_inline long atomic_long_inc_return_acquire(atomic_long_t *v) { return atomic64_inc_return_acquire(v); } -static inline long +static __always_inline long atomic_long_inc_return_release(atomic_long_t *v) { return atomic64_inc_return_release(v); } -static inline long +static __always_inline long atomic_long_inc_return_relaxed(atomic_long_t *v) { return atomic64_inc_return_relaxed(v); } -static inline long +static __always_inline long atomic_long_fetch_inc(atomic_long_t *v) { return atomic64_fetch_inc(v); } -static inline long +static __always_inline long atomic_long_fetch_inc_acquire(atomic_long_t *v) { return atomic64_fetch_inc_acquire(v); } -static inline long +static __always_inline long atomic_long_fetch_inc_release(atomic_long_t *v) { return atomic64_fetch_inc_release(v); } -static inline long +static __always_inline long atomic_long_fetch_inc_relaxed(atomic_long_t *v) { return atomic64_fetch_inc_relaxed(v); } -static inline void +static __always_inline void atomic_long_dec(atomic_long_t *v) { atomic64_dec(v); } -static inline long +static __always_inline long atomic_long_dec_return(atomic_long_t *v) { return atomic64_dec_return(v); } -static inline long +static __always_inline long atomic_long_dec_return_acquire(atomic_long_t *v) { return atomic64_dec_return_acquire(v); } -static inline long +static __always_inline long atomic_long_dec_return_release(atomic_long_t *v) { return atomic64_dec_return_release(v); } -static inline long +static __always_inline long atomic_long_dec_return_relaxed(atomic_long_t *v) { return atomic64_dec_return_relaxed(v); } -static inline long +static __always_inline long atomic_long_fetch_dec(atomic_long_t *v) { return atomic64_fetch_dec(v); } -static inline long +static __always_inline long atomic_long_fetch_dec_acquire(atomic_long_t *v) { return atomic64_fetch_dec_acquire(v); } -static inline long +static __always_inline long atomic_long_fetch_dec_release(atomic_long_t *v) { return atomic64_fetch_dec_release(v); } -static inline long +static __always_inline long atomic_long_fetch_dec_relaxed(atomic_long_t *v) { return atomic64_fetch_dec_relaxed(v); } -static inline void +static __always_inline void atomic_long_and(long i, atomic_long_t *v) { atomic64_and(i, v); } -static inline long +static __always_inline long atomic_long_fetch_and(long i, atomic_long_t *v) { return atomic64_fetch_and(i, v); } -static inline long +static __always_inline long atomic_long_fetch_and_acquire(long i, atomic_long_t *v) { return atomic64_fetch_and_acquire(i, v); } -static inline long +static __always_inline long atomic_long_fetch_and_release(long i, atomic_long_t *v) { return atomic64_fetch_and_release(i, v); } -static inline long +static __always_inline long atomic_long_fetch_and_relaxed(long i, atomic_long_t *v) { return atomic64_fetch_and_relaxed(i, v); } -static inline void +static __always_inline void atomic_long_andnot(long i, atomic_long_t *v) { atomic64_andnot(i, v); } -static inline long +static __always_inline long atomic_long_fetch_andnot(long i, atomic_long_t *v) { return atomic64_fetch_andnot(i, v); } -static inline long +static __always_inline long atomic_long_fetch_andnot_acquire(long i, atomic_long_t *v) { return atomic64_fetch_andnot_acquire(i, v); } -static inline long +static __always_inline long atomic_long_fetch_andnot_release(long i, atomic_long_t *v) { return atomic64_fetch_andnot_release(i, v); } -static inline long +static __always_inline long atomic_long_fetch_andnot_relaxed(long i, atomic_long_t *v) { return atomic64_fetch_andnot_relaxed(i, v); } -static inline void +static __always_inline void atomic_long_or(long i, atomic_long_t *v) { atomic64_or(i, v); } -static inline long +static __always_inline long atomic_long_fetch_or(long i, atomic_long_t *v) { return atomic64_fetch_or(i, v); } -static inline long +static __always_inline long atomic_long_fetch_or_acquire(long i, atomic_long_t *v) { return atomic64_fetch_or_acquire(i, v); } -static inline long +static __always_inline long atomic_long_fetch_or_release(long i, atomic_long_t *v) { return atomic64_fetch_or_release(i, v); } -static inline long +static __always_inline long atomic_long_fetch_or_relaxed(long i, atomic_long_t *v) { return atomic64_fetch_or_relaxed(i, v); } -static inline void +static __always_inline void atomic_long_xor(long i, atomic_long_t *v) { atomic64_xor(i, v); } -static inline long +static __always_inline long atomic_long_fetch_xor(long i, atomic_long_t *v) { return atomic64_fetch_xor(i, v); } -static inline long +static __always_inline long atomic_long_fetch_xor_acquire(long i, atomic_long_t *v) { return atomic64_fetch_xor_acquire(i, v); } -static inline long +static __always_inline long atomic_long_fetch_xor_release(long i, atomic_long_t *v) { return atomic64_fetch_xor_release(i, v); } -static inline long +static __always_inline long atomic_long_fetch_xor_relaxed(long i, atomic_long_t *v) { return atomic64_fetch_xor_relaxed(i, v); } -static inline long +static __always_inline long atomic_long_xchg(atomic_long_t *v, long i) { return atomic64_xchg(v, i); } -static inline long +static __always_inline long atomic_long_xchg_acquire(atomic_long_t *v, long i) { return atomic64_xchg_acquire(v, i); } -static inline long +static __always_inline long atomic_long_xchg_release(atomic_long_t *v, long i) { return atomic64_xchg_release(v, i); } -static inline long +static __always_inline long atomic_long_xchg_relaxed(atomic_long_t *v, long i) { return atomic64_xchg_relaxed(v, i); } -static inline long +static __always_inline long atomic_long_cmpxchg(atomic_long_t *v, long old, long new) { return atomic64_cmpxchg(v, old, new); } -static inline long +static __always_inline long atomic_long_cmpxchg_acquire(atomic_long_t *v, long old, long new) { return atomic64_cmpxchg_acquire(v, old, new); } -static inline long +static __always_inline long atomic_long_cmpxchg_release(atomic_long_t *v, long old, long new) { return atomic64_cmpxchg_release(v, old, new); } -static inline long +static __always_inline long atomic_long_cmpxchg_relaxed(atomic_long_t *v, long old, long new) { return atomic64_cmpxchg_relaxed(v, old, new); } -static inline bool +static __always_inline bool atomic_long_try_cmpxchg(atomic_long_t *v, long *old, long new) { return atomic64_try_cmpxchg(v, (s64 *)old, new); } -static inline bool +static __always_inline bool atomic_long_try_cmpxchg_acquire(atomic_long_t *v, long *old, long new) { return atomic64_try_cmpxchg_acquire(v, (s64 *)old, new); } -static inline bool +static __always_inline bool atomic_long_try_cmpxchg_release(atomic_long_t *v, long *old, long new) { return atomic64_try_cmpxchg_release(v, (s64 *)old, new); } -static inline bool +static __always_inline bool atomic_long_try_cmpxchg_relaxed(atomic_long_t *v, long *old, long new) { return atomic64_try_cmpxchg_relaxed(v, (s64 *)old, new); } -static inline bool +static __always_inline bool atomic_long_sub_and_test(long i, atomic_long_t *v) { return atomic64_sub_and_test(i, v); } -static inline bool +static __always_inline bool atomic_long_dec_and_test(atomic_long_t *v) { return atomic64_dec_and_test(v); } -static inline bool +static __always_inline bool atomic_long_inc_and_test(atomic_long_t *v) { return atomic64_inc_and_test(v); } -static inline bool +static __always_inline bool atomic_long_add_negative(long i, atomic_long_t *v) { return atomic64_add_negative(i, v); } -static inline long +static __always_inline long atomic_long_fetch_add_unless(atomic_long_t *v, long a, long u) { return atomic64_fetch_add_unless(v, a, u); } -static inline bool +static __always_inline bool atomic_long_add_unless(atomic_long_t *v, long a, long u) { return atomic64_add_unless(v, a, u); } -static inline bool +static __always_inline bool atomic_long_inc_not_zero(atomic_long_t *v) { return atomic64_inc_not_zero(v); } -static inline bool +static __always_inline bool atomic_long_inc_unless_negative(atomic_long_t *v) { return atomic64_inc_unless_negative(v); } -static inline bool +static __always_inline bool atomic_long_dec_unless_positive(atomic_long_t *v) { return atomic64_dec_unless_positive(v); } -static inline long +static __always_inline long atomic_long_dec_if_positive(atomic_long_t *v) { return atomic64_dec_if_positive(v); @@ -516,493 +517,493 @@ atomic_long_dec_if_positive(atomic_long_t *v) #else /* CONFIG_64BIT */ -static inline long +static __always_inline long atomic_long_read(const atomic_long_t *v) { return atomic_read(v); } -static inline long +static __always_inline long atomic_long_read_acquire(const atomic_long_t *v) { return atomic_read_acquire(v); } -static inline void +static __always_inline void atomic_long_set(atomic_long_t *v, long i) { atomic_set(v, i); } -static inline void +static __always_inline void atomic_long_set_release(atomic_long_t *v, long i) { atomic_set_release(v, i); } -static inline void +static __always_inline void atomic_long_add(long i, atomic_long_t *v) { atomic_add(i, v); } -static inline long +static __always_inline long atomic_long_add_return(long i, atomic_long_t *v) { return atomic_add_return(i, v); } -static inline long +static __always_inline long atomic_long_add_return_acquire(long i, atomic_long_t *v) { return atomic_add_return_acquire(i, v); } -static inline long +static __always_inline long atomic_long_add_return_release(long i, atomic_long_t *v) { return atomic_add_return_release(i, v); } -static inline long +static __always_inline long atomic_long_add_return_relaxed(long i, atomic_long_t *v) { return atomic_add_return_relaxed(i, v); } -static inline long +static __always_inline long atomic_long_fetch_add(long i, atomic_long_t *v) { return atomic_fetch_add(i, v); } -static inline long +static __always_inline long atomic_long_fetch_add_acquire(long i, atomic_long_t *v) { return atomic_fetch_add_acquire(i, v); } -static inline long +static __always_inline long atomic_long_fetch_add_release(long i, atomic_long_t *v) { return atomic_fetch_add_release(i, v); } -static inline long +static __always_inline long atomic_long_fetch_add_relaxed(long i, atomic_long_t *v) { return atomic_fetch_add_relaxed(i, v); } -static inline void +static __always_inline void atomic_long_sub(long i, atomic_long_t *v) { atomic_sub(i, v); } -static inline long +static __always_inline long atomic_long_sub_return(long i, atomic_long_t *v) { return atomic_sub_return(i, v); } -static inline long +static __always_inline long atomic_long_sub_return_acquire(long i, atomic_long_t *v) { return atomic_sub_return_acquire(i, v); } -static inline long +static __always_inline long atomic_long_sub_return_release(long i, atomic_long_t *v) { return atomic_sub_return_release(i, v); } -static inline long +static __always_inline long atomic_long_sub_return_relaxed(long i, atomic_long_t *v) { return atomic_sub_return_relaxed(i, v); } -static inline long +static __always_inline long atomic_long_fetch_sub(long i, atomic_long_t *v) { return atomic_fetch_sub(i, v); } -static inline long +static __always_inline long atomic_long_fetch_sub_acquire(long i, atomic_long_t *v) { return atomic_fetch_sub_acquire(i, v); } -static inline long +static __always_inline long atomic_long_fetch_sub_release(long i, atomic_long_t *v) { return atomic_fetch_sub_release(i, v); } -static inline long +static __always_inline long atomic_long_fetch_sub_relaxed(long i, atomic_long_t *v) { return atomic_fetch_sub_relaxed(i, v); } -static inline void +static __always_inline void atomic_long_inc(atomic_long_t *v) { atomic_inc(v); } -static inline long +static __always_inline long atomic_long_inc_return(atomic_long_t *v) { return atomic_inc_return(v); } -static inline long +static __always_inline long atomic_long_inc_return_acquire(atomic_long_t *v) { return atomic_inc_return_acquire(v); } -static inline long +static __always_inline long atomic_long_inc_return_release(atomic_long_t *v) { return atomic_inc_return_release(v); } -static inline long +static __always_inline long atomic_long_inc_return_relaxed(atomic_long_t *v) { return atomic_inc_return_relaxed(v); } -static inline long +static __always_inline long atomic_long_fetch_inc(atomic_long_t *v) { return atomic_fetch_inc(v); } -static inline long +static __always_inline long atomic_long_fetch_inc_acquire(atomic_long_t *v) { return atomic_fetch_inc_acquire(v); } -static inline long +static __always_inline long atomic_long_fetch_inc_release(atomic_long_t *v) { return atomic_fetch_inc_release(v); } -static inline long +static __always_inline long atomic_long_fetch_inc_relaxed(atomic_long_t *v) { return atomic_fetch_inc_relaxed(v); } -static inline void +static __always_inline void atomic_long_dec(atomic_long_t *v) { atomic_dec(v); } -static inline long +static __always_inline long atomic_long_dec_return(atomic_long_t *v) { return atomic_dec_return(v); } -static inline long +static __always_inline long atomic_long_dec_return_acquire(atomic_long_t *v) { return atomic_dec_return_acquire(v); } -static inline long +static __always_inline long atomic_long_dec_return_release(atomic_long_t *v) { return atomic_dec_return_release(v); } -static inline long +static __always_inline long atomic_long_dec_return_relaxed(atomic_long_t *v) { return atomic_dec_return_relaxed(v); } -static inline long +static __always_inline long atomic_long_fetch_dec(atomic_long_t *v) { return atomic_fetch_dec(v); } -static inline long +static __always_inline long atomic_long_fetch_dec_acquire(atomic_long_t *v) { return atomic_fetch_dec_acquire(v); } -static inline long +static __always_inline long atomic_long_fetch_dec_release(atomic_long_t *v) { return atomic_fetch_dec_release(v); } -static inline long +static __always_inline long atomic_long_fetch_dec_relaxed(atomic_long_t *v) { return atomic_fetch_dec_relaxed(v); } -static inline void +static __always_inline void atomic_long_and(long i, atomic_long_t *v) { atomic_and(i, v); } -static inline long +static __always_inline long atomic_long_fetch_and(long i, atomic_long_t *v) { return atomic_fetch_and(i, v); } -static inline long +static __always_inline long atomic_long_fetch_and_acquire(long i, atomic_long_t *v) { return atomic_fetch_and_acquire(i, v); } -static inline long +static __always_inline long atomic_long_fetch_and_release(long i, atomic_long_t *v) { return atomic_fetch_and_release(i, v); } -static inline long +static __always_inline long atomic_long_fetch_and_relaxed(long i, atomic_long_t *v) { return atomic_fetch_and_relaxed(i, v); } -static inline void +static __always_inline void atomic_long_andnot(long i, atomic_long_t *v) { atomic_andnot(i, v); } -static inline long +static __always_inline long atomic_long_fetch_andnot(long i, atomic_long_t *v) { return atomic_fetch_andnot(i, v); } -static inline long +static __always_inline long atomic_long_fetch_andnot_acquire(long i, atomic_long_t *v) { return atomic_fetch_andnot_acquire(i, v); } -static inline long +static __always_inline long atomic_long_fetch_andnot_release(long i, atomic_long_t *v) { return atomic_fetch_andnot_release(i, v); } -static inline long +static __always_inline long atomic_long_fetch_andnot_relaxed(long i, atomic_long_t *v) { return atomic_fetch_andnot_relaxed(i, v); } -static inline void +static __always_inline void atomic_long_or(long i, atomic_long_t *v) { atomic_or(i, v); } -static inline long +static __always_inline long atomic_long_fetch_or(long i, atomic_long_t *v) { return atomic_fetch_or(i, v); } -static inline long +static __always_inline long atomic_long_fetch_or_acquire(long i, atomic_long_t *v) { return atomic_fetch_or_acquire(i, v); } -static inline long +static __always_inline long atomic_long_fetch_or_release(long i, atomic_long_t *v) { return atomic_fetch_or_release(i, v); } -static inline long +static __always_inline long atomic_long_fetch_or_relaxed(long i, atomic_long_t *v) { return atomic_fetch_or_relaxed(i, v); } -static inline void +static __always_inline void atomic_long_xor(long i, atomic_long_t *v) { atomic_xor(i, v); } -static inline long +static __always_inline long atomic_long_fetch_xor(long i, atomic_long_t *v) { return atomic_fetch_xor(i, v); } -static inline long +static __always_inline long atomic_long_fetch_xor_acquire(long i, atomic_long_t *v) { return atomic_fetch_xor_acquire(i, v); } -static inline long +static __always_inline long atomic_long_fetch_xor_release(long i, atomic_long_t *v) { return atomic_fetch_xor_release(i, v); } -static inline long +static __always_inline long atomic_long_fetch_xor_relaxed(long i, atomic_long_t *v) { return atomic_fetch_xor_relaxed(i, v); } -static inline long +static __always_inline long atomic_long_xchg(atomic_long_t *v, long i) { return atomic_xchg(v, i); } -static inline long +static __always_inline long atomic_long_xchg_acquire(atomic_long_t *v, long i) { return atomic_xchg_acquire(v, i); } -static inline long +static __always_inline long atomic_long_xchg_release(atomic_long_t *v, long i) { return atomic_xchg_release(v, i); } -static inline long +static __always_inline long atomic_long_xchg_relaxed(atomic_long_t *v, long i) { return atomic_xchg_relaxed(v, i); } -static inline long +static __always_inline long atomic_long_cmpxchg(atomic_long_t *v, long old, long new) { return atomic_cmpxchg(v, old, new); } -static inline long +static __always_inline long atomic_long_cmpxchg_acquire(atomic_long_t *v, long old, long new) { return atomic_cmpxchg_acquire(v, old, new); } -static inline long +static __always_inline long atomic_long_cmpxchg_release(atomic_long_t *v, long old, long new) { return atomic_cmpxchg_release(v, old, new); } -static inline long +static __always_inline long atomic_long_cmpxchg_relaxed(atomic_long_t *v, long old, long new) { return atomic_cmpxchg_relaxed(v, old, new); } -static inline bool +static __always_inline bool atomic_long_try_cmpxchg(atomic_long_t *v, long *old, long new) { return atomic_try_cmpxchg(v, (int *)old, new); } -static inline bool +static __always_inline bool atomic_long_try_cmpxchg_acquire(atomic_long_t *v, long *old, long new) { return atomic_try_cmpxchg_acquire(v, (int *)old, new); } -static inline bool +static __always_inline bool atomic_long_try_cmpxchg_release(atomic_long_t *v, long *old, long new) { return atomic_try_cmpxchg_release(v, (int *)old, new); } -static inline bool +static __always_inline bool atomic_long_try_cmpxchg_relaxed(atomic_long_t *v, long *old, long new) { return atomic_try_cmpxchg_relaxed(v, (int *)old, new); } -static inline bool +static __always_inline bool atomic_long_sub_and_test(long i, atomic_long_t *v) { return atomic_sub_and_test(i, v); } -static inline bool +static __always_inline bool atomic_long_dec_and_test(atomic_long_t *v) { return atomic_dec_and_test(v); } -static inline bool +static __always_inline bool atomic_long_inc_and_test(atomic_long_t *v) { return atomic_inc_and_test(v); } -static inline bool +static __always_inline bool atomic_long_add_negative(long i, atomic_long_t *v) { return atomic_add_negative(i, v); } -static inline long +static __always_inline long atomic_long_fetch_add_unless(atomic_long_t *v, long a, long u) { return atomic_fetch_add_unless(v, a, u); } -static inline bool +static __always_inline bool atomic_long_add_unless(atomic_long_t *v, long a, long u) { return atomic_add_unless(v, a, u); } -static inline bool +static __always_inline bool atomic_long_inc_not_zero(atomic_long_t *v) { return atomic_inc_not_zero(v); } -static inline bool +static __always_inline bool atomic_long_inc_unless_negative(atomic_long_t *v) { return atomic_inc_unless_negative(v); } -static inline bool +static __always_inline bool atomic_long_dec_unless_positive(atomic_long_t *v) { return atomic_dec_unless_positive(v); } -static inline long +static __always_inline long atomic_long_dec_if_positive(atomic_long_t *v) { return atomic_dec_if_positive(v); @@ -1010,4 +1011,4 @@ atomic_long_dec_if_positive(atomic_long_t *v) #endif /* CONFIG_64BIT */ #endif /* _ASM_GENERIC_ATOMIC_LONG_H */ -// 77558968132ce4f911ad53f6f52ce423006f6268 +// a624200981f552b2c6be4f32fe44da8289f30d87 diff --git a/include/asm-generic/bitops/instrumented-atomic.h b/include/asm-generic/bitops/instrumented-atomic.h index 18ce3c9e8eec..fb2cb33a4013 100644 --- a/include/asm-generic/bitops/instrumented-atomic.h +++ b/include/asm-generic/bitops/instrumented-atomic.h @@ -11,7 +11,7 @@ #ifndef _ASM_GENERIC_BITOPS_INSTRUMENTED_ATOMIC_H #define _ASM_GENERIC_BITOPS_INSTRUMENTED_ATOMIC_H -#include <linux/kasan-checks.h> +#include <linux/instrumented.h> /** * set_bit - Atomically set a bit in memory @@ -25,7 +25,7 @@ */ static inline void set_bit(long nr, volatile unsigned long *addr) { - kasan_check_write(addr + BIT_WORD(nr), sizeof(long)); + instrument_atomic_write(addr + BIT_WORD(nr), sizeof(long)); arch_set_bit(nr, addr); } @@ -38,7 +38,7 @@ static inline void set_bit(long nr, volatile unsigned long *addr) */ static inline void clear_bit(long nr, volatile unsigned long *addr) { - kasan_check_write(addr + BIT_WORD(nr), sizeof(long)); + instrument_atomic_write(addr + BIT_WORD(nr), sizeof(long)); arch_clear_bit(nr, addr); } @@ -54,7 +54,7 @@ static inline void clear_bit(long nr, volatile unsigned long *addr) */ static inline void change_bit(long nr, volatile unsigned long *addr) { - kasan_check_write(addr + BIT_WORD(nr), sizeof(long)); + instrument_atomic_write(addr + BIT_WORD(nr), sizeof(long)); arch_change_bit(nr, addr); } @@ -67,7 +67,7 @@ static inline void change_bit(long nr, volatile unsigned long *addr) */ static inline bool test_and_set_bit(long nr, volatile unsigned long *addr) { - kasan_check_write(addr + BIT_WORD(nr), sizeof(long)); + instrument_atomic_write(addr + BIT_WORD(nr), sizeof(long)); return arch_test_and_set_bit(nr, addr); } @@ -80,7 +80,7 @@ static inline bool test_and_set_bit(long nr, volatile unsigned long *addr) */ static inline bool test_and_clear_bit(long nr, volatile unsigned long *addr) { - kasan_check_write(addr + BIT_WORD(nr), sizeof(long)); + instrument_atomic_write(addr + BIT_WORD(nr), sizeof(long)); return arch_test_and_clear_bit(nr, addr); } @@ -93,7 +93,7 @@ static inline bool test_and_clear_bit(long nr, volatile unsigned long *addr) */ static inline bool test_and_change_bit(long nr, volatile unsigned long *addr) { - kasan_check_write(addr + BIT_WORD(nr), sizeof(long)); + instrument_atomic_write(addr + BIT_WORD(nr), sizeof(long)); return arch_test_and_change_bit(nr, addr); } diff --git a/include/asm-generic/bitops/instrumented-lock.h b/include/asm-generic/bitops/instrumented-lock.h index ec53fdeea9ec..b9bec468ae03 100644 --- a/include/asm-generic/bitops/instrumented-lock.h +++ b/include/asm-generic/bitops/instrumented-lock.h @@ -11,7 +11,7 @@ #ifndef _ASM_GENERIC_BITOPS_INSTRUMENTED_LOCK_H #define _ASM_GENERIC_BITOPS_INSTRUMENTED_LOCK_H -#include <linux/kasan-checks.h> +#include <linux/instrumented.h> /** * clear_bit_unlock - Clear a bit in memory, for unlock @@ -22,7 +22,7 @@ */ static inline void clear_bit_unlock(long nr, volatile unsigned long *addr) { - kasan_check_write(addr + BIT_WORD(nr), sizeof(long)); + instrument_atomic_write(addr + BIT_WORD(nr), sizeof(long)); arch_clear_bit_unlock(nr, addr); } @@ -37,7 +37,7 @@ static inline void clear_bit_unlock(long nr, volatile unsigned long *addr) */ static inline void __clear_bit_unlock(long nr, volatile unsigned long *addr) { - kasan_check_write(addr + BIT_WORD(nr), sizeof(long)); + instrument_write(addr + BIT_WORD(nr), sizeof(long)); arch___clear_bit_unlock(nr, addr); } @@ -52,7 +52,7 @@ static inline void __clear_bit_unlock(long nr, volatile unsigned long *addr) */ static inline bool test_and_set_bit_lock(long nr, volatile unsigned long *addr) { - kasan_check_write(addr + BIT_WORD(nr), sizeof(long)); + instrument_atomic_write(addr + BIT_WORD(nr), sizeof(long)); return arch_test_and_set_bit_lock(nr, addr); } @@ -71,7 +71,7 @@ static inline bool test_and_set_bit_lock(long nr, volatile unsigned long *addr) static inline bool clear_bit_unlock_is_negative_byte(long nr, volatile unsigned long *addr) { - kasan_check_write(addr + BIT_WORD(nr), sizeof(long)); + instrument_atomic_write(addr + BIT_WORD(nr), sizeof(long)); return arch_clear_bit_unlock_is_negative_byte(nr, addr); } /* Let everybody know we have it. */ diff --git a/include/asm-generic/bitops/instrumented-non-atomic.h b/include/asm-generic/bitops/instrumented-non-atomic.h index 95ff28d128a1..20f788a25ef9 100644 --- a/include/asm-generic/bitops/instrumented-non-atomic.h +++ b/include/asm-generic/bitops/instrumented-non-atomic.h @@ -11,7 +11,7 @@ #ifndef _ASM_GENERIC_BITOPS_INSTRUMENTED_NON_ATOMIC_H #define _ASM_GENERIC_BITOPS_INSTRUMENTED_NON_ATOMIC_H -#include <linux/kasan-checks.h> +#include <linux/instrumented.h> /** * __set_bit - Set a bit in memory @@ -24,7 +24,7 @@ */ static inline void __set_bit(long nr, volatile unsigned long *addr) { - kasan_check_write(addr + BIT_WORD(nr), sizeof(long)); + instrument_write(addr + BIT_WORD(nr), sizeof(long)); arch___set_bit(nr, addr); } @@ -39,7 +39,7 @@ static inline void __set_bit(long nr, volatile unsigned long *addr) */ static inline void __clear_bit(long nr, volatile unsigned long *addr) { - kasan_check_write(addr + BIT_WORD(nr), sizeof(long)); + instrument_write(addr + BIT_WORD(nr), sizeof(long)); arch___clear_bit(nr, addr); } @@ -54,7 +54,7 @@ static inline void __clear_bit(long nr, volatile unsigned long *addr) */ static inline void __change_bit(long nr, volatile unsigned long *addr) { - kasan_check_write(addr + BIT_WORD(nr), sizeof(long)); + instrument_write(addr + BIT_WORD(nr), sizeof(long)); arch___change_bit(nr, addr); } @@ -68,7 +68,7 @@ static inline void __change_bit(long nr, volatile unsigned long *addr) */ static inline bool __test_and_set_bit(long nr, volatile unsigned long *addr) { - kasan_check_write(addr + BIT_WORD(nr), sizeof(long)); + instrument_write(addr + BIT_WORD(nr), sizeof(long)); return arch___test_and_set_bit(nr, addr); } @@ -82,7 +82,7 @@ static inline bool __test_and_set_bit(long nr, volatile unsigned long *addr) */ static inline bool __test_and_clear_bit(long nr, volatile unsigned long *addr) { - kasan_check_write(addr + BIT_WORD(nr), sizeof(long)); + instrument_write(addr + BIT_WORD(nr), sizeof(long)); return arch___test_and_clear_bit(nr, addr); } @@ -96,7 +96,7 @@ static inline bool __test_and_clear_bit(long nr, volatile unsigned long *addr) */ static inline bool __test_and_change_bit(long nr, volatile unsigned long *addr) { - kasan_check_write(addr + BIT_WORD(nr), sizeof(long)); + instrument_write(addr + BIT_WORD(nr), sizeof(long)); return arch___test_and_change_bit(nr, addr); } @@ -107,7 +107,7 @@ static inline bool __test_and_change_bit(long nr, volatile unsigned long *addr) */ static inline bool test_bit(long nr, const volatile unsigned long *addr) { - kasan_check_read(addr + BIT_WORD(nr), sizeof(long)); + instrument_atomic_read(addr + BIT_WORD(nr), sizeof(long)); return arch_test_bit(nr, addr); } diff --git a/include/linux/compiler-clang.h b/include/linux/compiler-clang.h index 790c0c6b8552..ee37256ec8bd 100644 --- a/include/linux/compiler-clang.h +++ b/include/linux/compiler-clang.h @@ -16,7 +16,7 @@ #define KASAN_ABI_VERSION 5 #if __has_feature(address_sanitizer) || __has_feature(hwaddress_sanitizer) -/* emulate gcc's __SANITIZE_ADDRESS__ flag */ +/* Emulate GCC's __SANITIZE_ADDRESS__ flag */ #define __SANITIZE_ADDRESS__ #define __no_sanitize_address \ __attribute__((no_sanitize("address", "hwaddress"))) @@ -24,6 +24,15 @@ #define __no_sanitize_address #endif +#if __has_feature(thread_sanitizer) +/* emulate gcc's __SANITIZE_THREAD__ flag */ +#define __SANITIZE_THREAD__ +#define __no_sanitize_thread \ + __attribute__((no_sanitize("thread"))) +#else +#define __no_sanitize_thread +#endif + /* * Not all versions of clang implement the the type-generic versions * of the builtin overflow checkers. Fortunately, clang implements diff --git a/include/linux/compiler-gcc.h b/include/linux/compiler-gcc.h index e2f725273261..7dd4e0349ef3 100644 --- a/include/linux/compiler-gcc.h +++ b/include/linux/compiler-gcc.h @@ -144,6 +144,12 @@ #define __no_sanitize_address #endif +#if defined(__SANITIZE_THREAD__) && __has_attribute(__no_sanitize_thread__) +#define __no_sanitize_thread __attribute__((no_sanitize_thread)) +#else +#define __no_sanitize_thread +#endif + #if GCC_VERSION >= 50100 #define COMPILER_HAS_GENERIC_BUILTIN_OVERFLOW 1 #endif diff --git a/include/linux/compiler.h b/include/linux/compiler.h index 33d3a2e5abab..f09ebbf16562 100644 --- a/include/linux/compiler.h +++ b/include/linux/compiler.h @@ -250,6 +250,27 @@ void ftrace_likely_update(struct ftrace_likely_data *f, int val, */ #include <asm/barrier.h> #include <linux/kasan-checks.h> +#include <linux/kcsan-checks.h> + +/** + * data_race - mark an expression as containing intentional data races + * + * This data_race() macro is useful for situations in which data races + * should be forgiven. One example is diagnostic code that accesses + * shared variables but is not a part of the core synchronization design. + * + * This macro *does not* affect normal code generation, but is a hint + * to tooling that data races here are to be ignored. + */ +#define data_race(expr) \ +({ \ + __kcsan_disable_current(); \ + ({ \ + __unqual_scalar_typeof(({ expr; })) __v = ({ expr; }); \ + __kcsan_enable_current(); \ + __v; \ + }); \ +}) /* * Use __READ_ONCE() instead of READ_ONCE() if you do not require any @@ -260,7 +281,9 @@ void ftrace_likely_update(struct ftrace_likely_data *f, int val, #define __READ_ONCE_SCALAR(x) \ ({ \ - __unqual_scalar_typeof(x) __x = __READ_ONCE(x); \ + typeof(x) *__xp = &(x); \ + __unqual_scalar_typeof(x) __x = data_race(__READ_ONCE(*__xp)); \ + kcsan_check_atomic_read(__xp, sizeof(*__xp)); \ smp_read_barrier_depends(); \ (typeof(x))__x; \ }) @@ -271,15 +294,22 @@ void ftrace_likely_update(struct ftrace_likely_data *f, int val, __READ_ONCE_SCALAR(x); \ }) -#define __WRITE_ONCE(x, val) \ -do { \ - *(volatile typeof(x) *)&(x) = (val); \ +#define __WRITE_ONCE(x, val) \ +do { \ + *(volatile typeof(x) *)&(x) = (val); \ +} while (0) + +#define __WRITE_ONCE_SCALAR(x, val) \ +do { \ + typeof(x) *__xp = &(x); \ + kcsan_check_atomic_write(__xp, sizeof(*__xp)); \ + data_race(({ __WRITE_ONCE(*__xp, val); 0; })); \ } while (0) -#define WRITE_ONCE(x, val) \ -do { \ - compiletime_assert_rwonce_type(x); \ - __WRITE_ONCE(x, val); \ +#define WRITE_ONCE(x, val) \ +do { \ + compiletime_assert_rwonce_type(x); \ + __WRITE_ONCE_SCALAR(x, val); \ } while (0) #ifdef CONFIG_KASAN @@ -290,11 +320,30 @@ do { \ * '__maybe_unused' allows us to avoid defined-but-not-used warnings. */ # define __no_kasan_or_inline __no_sanitize_address notrace __maybe_unused +# define __no_sanitize_or_inline __no_kasan_or_inline #else # define __no_kasan_or_inline __always_inline #endif -static __no_kasan_or_inline +#define __no_kcsan __no_sanitize_thread +#ifdef __SANITIZE_THREAD__ +/* + * Rely on __SANITIZE_THREAD__ instead of CONFIG_KCSAN, to avoid not inlining in + * compilation units where instrumentation is disabled. The attribute 'noinline' + * is required for older compilers, where implicit inlining of very small + * functions renders __no_sanitize_thread ineffective. + */ +# define __no_kcsan_or_inline __no_kcsan noinline notrace __maybe_unused +# define __no_sanitize_or_inline __no_kcsan_or_inline +#else +# define __no_kcsan_or_inline __always_inline +#endif + +#ifndef __no_sanitize_or_inline +#define __no_sanitize_or_inline __always_inline +#endif + +static __no_sanitize_or_inline unsigned long __read_once_word_nocheck(const void *addr) { return __READ_ONCE(*(unsigned long *)addr); @@ -302,8 +351,8 @@ unsigned long __read_once_word_nocheck(const void *addr) /* * Use READ_ONCE_NOCHECK() instead of READ_ONCE() if you need to load a - * word from memory atomically but without telling KASAN. This is usually - * used by unwinding code when walking the stack of a running process. + * word from memory atomically but without telling KASAN/KCSAN. This is + * usually used by unwinding code when walking the stack of a running process. */ #define READ_ONCE_NOCHECK(x) \ ({ \ diff --git a/include/linux/instrumented.h b/include/linux/instrumented.h new file mode 100644 index 000000000000..43e6ea591975 --- /dev/null +++ b/include/linux/instrumented.h @@ -0,0 +1,109 @@ +/* SPDX-License-Identifier: GPL-2.0 */ + +/* + * This header provides generic wrappers for memory access instrumentation that + * the compiler cannot emit for: KASAN, KCSAN. + */ +#ifndef _LINUX_INSTRUMENTED_H +#define _LINUX_INSTRUMENTED_H + +#include <linux/compiler.h> +#include <linux/kasan-checks.h> +#include <linux/kcsan-checks.h> +#include <linux/types.h> + +/** + * instrument_read - instrument regular read access + * + * Instrument a regular read access. The instrumentation should be inserted + * before the actual read happens. + * + * @ptr address of access + * @size size of access + */ +static __always_inline void instrument_read(const volatile void *v, size_t size) +{ + kasan_check_read(v, size); + kcsan_check_read(v, size); +} + +/** + * instrument_write - instrument regular write access + * + * Instrument a regular write access. The instrumentation should be inserted + * before the actual write happens. + * + * @ptr address of access + * @size size of access + */ +static __always_inline void instrument_write(const volatile void *v, size_t size) +{ + kasan_check_write(v, size); + kcsan_check_write(v, size); +} + +/** + * instrument_atomic_read - instrument atomic read access + * + * Instrument an atomic read access. The instrumentation should be inserted + * before the actual read happens. + * + * @ptr address of access + * @size size of access + */ +static __always_inline void instrument_atomic_read(const volatile void *v, size_t size) +{ + kasan_check_read(v, size); + kcsan_check_atomic_read(v, size); +} + +/** + * instrument_atomic_write - instrument atomic write access + * + * Instrument an atomic write access. The instrumentation should be inserted + * before the actual write happens. + * + * @ptr address of access + * @size size of access + */ +static __always_inline void instrument_atomic_write(const volatile void *v, size_t size) +{ + kasan_check_write(v, size); + kcsan_check_atomic_write(v, size); +} + +/** + * instrument_copy_to_user - instrument reads of copy_to_user + * + * Instrument reads from kernel memory, that are due to copy_to_user (and + * variants). The instrumentation must be inserted before the accesses. + * + * @to destination address + * @from source address + * @n number of bytes to copy + */ +static __always_inline void +instrument_copy_to_user(void __user *to, const void *from, unsigned long n) +{ + kasan_check_read(from, n); + kcsan_check_read(from, n); +} + +/** + * instrument_copy_from_user - instrument writes of copy_from_user + * + * Instrument writes to kernel memory, that are due to copy_from_user (and + * variants). The instrumentation should be inserted before the accesses. + * + * @to destination address + * @from source address + * @n number of bytes to copy + */ +static __always_inline void +instrument_copy_from_user(const void *to, const void __user *from, unsigned long n) +{ + kasan_check_write(to, n); + kcsan_check_write(to, n); +} + +#endif /* _LINUX_INSTRUMENTED_H */ diff --git a/include/linux/kcsan-checks.h b/include/linux/kcsan-checks.h new file mode 100644 index 000000000000..7b0b9c44f5f3 --- /dev/null +++ b/include/linux/kcsan-checks.h @@ -0,0 +1,430 @@ +/* SPDX-License-Identifier: GPL-2.0 */ + +#ifndef _LINUX_KCSAN_CHECKS_H +#define _LINUX_KCSAN_CHECKS_H + +/* Note: Only include what is already included by compiler.h. */ +#include <linux/compiler_attributes.h> +#include <linux/types.h> + +/* + * ACCESS TYPE MODIFIERS + * + * <none>: normal read access; + * WRITE : write access; + * ATOMIC: access is atomic; + * ASSERT: access is not a regular access, but an assertion; + * SCOPED: access is a scoped access; + */ +#define KCSAN_ACCESS_WRITE 0x1 +#define KCSAN_ACCESS_ATOMIC 0x2 +#define KCSAN_ACCESS_ASSERT 0x4 +#define KCSAN_ACCESS_SCOPED 0x8 + +/* + * __kcsan_*: Always calls into the runtime when KCSAN is enabled. This may be used + * even in compilation units that selectively disable KCSAN, but must use KCSAN + * to validate access to an address. Never use these in header files! + */ +#ifdef CONFIG_KCSAN +/** + * __kcsan_check_access - check generic access for races + * + * @ptr: address of access + * @size: size of access + * @type: access type modifier + */ +void __kcsan_check_access(const volatile void *ptr, size_t size, int type); + +/** + * kcsan_disable_current - disable KCSAN for the current context + * + * Supports nesting. + */ +void kcsan_disable_current(void); + +/** + * kcsan_enable_current - re-enable KCSAN for the current context + * + * Supports nesting. + */ +void kcsan_enable_current(void); +void kcsan_enable_current_nowarn(void); /* Safe in uaccess regions. */ + +/** + * kcsan_nestable_atomic_begin - begin nestable atomic region + * + * Accesses within the atomic region may appear to race with other accesses but + * should be considered atomic. + */ +void kcsan_nestable_atomic_begin(void); + +/** + * kcsan_nestable_atomic_end - end nestable atomic region + */ +void kcsan_nestable_atomic_end(void); + +/** + * kcsan_flat_atomic_begin - begin flat atomic region + * + * Accesses within the atomic region may appear to race with other accesses but + * should be considered atomic. + */ +void kcsan_flat_atomic_begin(void); + +/** + * kcsan_flat_atomic_end - end flat atomic region + */ +void kcsan_flat_atomic_end(void); + +/** + * kcsan_atomic_next - consider following accesses as atomic + * + * Force treating the next n memory accesses for the current context as atomic + * operations. + * + * @n: number of following memory accesses to treat as atomic. + */ +void kcsan_atomic_next(int n); + +/** + * kcsan_set_access_mask - set access mask + * + * Set the access mask for all accesses for the current context if non-zero. + * Only value changes to bits set in the mask will be reported. + * + * @mask: bitmask + */ +void kcsan_set_access_mask(unsigned long mask); + +/* Scoped access information. */ +struct kcsan_scoped_access { + struct list_head list; + const volatile void *ptr; + size_t size; + int type; +}; +/* + * Automatically call kcsan_end_scoped_access() when kcsan_scoped_access goes + * out of scope; relies on attribute "cleanup", which is supported by all + * compilers that support KCSAN. + */ +#define __kcsan_cleanup_scoped \ + __maybe_unused __attribute__((__cleanup__(kcsan_end_scoped_access))) + +/** + * kcsan_begin_scoped_access - begin scoped access + * + * Begin scoped access and initialize @sa, which will cause KCSAN to + * continuously check the memory range in the current thread until + * kcsan_end_scoped_access() is called for @sa. + * + * Scoped accesses are implemented by appending @sa to an internal list for the + * current execution context, and then checked on every call into the KCSAN + * runtime. + * + * @ptr: address of access + * @size: size of access + * @type: access type modifier + * @sa: struct kcsan_scoped_access to use for the scope of the access + */ +struct kcsan_scoped_access * +kcsan_begin_scoped_access(const volatile void *ptr, size_t size, int type, + struct kcsan_scoped_access *sa); + +/** + * kcsan_end_scoped_access - end scoped access + * + * End a scoped access, which will stop KCSAN checking the memory range. + * Requires that kcsan_begin_scoped_access() was previously called once for @sa. + * + * @sa: a previously initialized struct kcsan_scoped_access + */ +void kcsan_end_scoped_access(struct kcsan_scoped_access *sa); + + +#else /* CONFIG_KCSAN */ + +static inline void __kcsan_check_access(const volatile void *ptr, size_t size, + int type) { } + +static inline void kcsan_disable_current(void) { } +static inline void kcsan_enable_current(void) { } +static inline void kcsan_enable_current_nowarn(void) { } +static inline void kcsan_nestable_atomic_begin(void) { } +static inline void kcsan_nestable_atomic_end(void) { } +static inline void kcsan_flat_atomic_begin(void) { } +static inline void kcsan_flat_atomic_end(void) { } +static inline void kcsan_atomic_next(int n) { } +static inline void kcsan_set_access_mask(unsigned long mask) { } + +struct kcsan_scoped_access { }; +#define __kcsan_cleanup_scoped __maybe_unused +static inline struct kcsan_scoped_access * +kcsan_begin_scoped_access(const volatile void *ptr, size_t size, int type, + struct kcsan_scoped_access *sa) { return sa; } +static inline void kcsan_end_scoped_access(struct kcsan_scoped_access *sa) { } + +#endif /* CONFIG_KCSAN */ + +#ifdef __SANITIZE_THREAD__ +/* + * Only calls into the runtime when the particular compilation unit has KCSAN + * instrumentation enabled. May be used in header files. + */ +#define kcsan_check_access __kcsan_check_access + +/* + * Only use these to disable KCSAN for accesses in the current compilation unit; + * calls into libraries may still perform KCSAN checks. + */ +#define __kcsan_disable_current kcsan_disable_current +#define __kcsan_enable_current kcsan_enable_current_nowarn +#else +static inline void kcsan_check_access(const volatile void *ptr, size_t size, + int type) { } +static inline void __kcsan_enable_current(void) { } +static inline void __kcsan_disable_current(void) { } +#endif + +/** + * __kcsan_check_read - check regular read access for races + * + * @ptr: address of access + * @size: size of access + */ +#define __kcsan_check_read(ptr, size) __kcsan_check_access(ptr, size, 0) + +/** + * __kcsan_check_write - check regular write access for races + * + * @ptr: address of access + * @size: size of access + */ +#define __kcsan_check_write(ptr, size) \ + __kcsan_check_access(ptr, size, KCSAN_ACCESS_WRITE) + +/** + * kcsan_check_read - check regular read access for races + * + * @ptr: address of access + * @size: size of access + */ +#define kcsan_check_read(ptr, size) kcsan_check_access(ptr, size, 0) + +/** + * kcsan_check_write - check regular write access for races + * + * @ptr: address of access + * @size: size of access + */ +#define kcsan_check_write(ptr, size) \ + kcsan_check_access(ptr, size, KCSAN_ACCESS_WRITE) + +/* + * Check for atomic accesses: if atomic accesses are not ignored, this simply + * aliases to kcsan_check_access(), otherwise becomes a no-op. + */ +#ifdef CONFIG_KCSAN_IGNORE_ATOMICS +#define kcsan_check_atomic_read(...) do { } while (0) +#define kcsan_check_atomic_write(...) do { } while (0) +#else +#define kcsan_check_atomic_read(ptr, size) \ + kcsan_check_access(ptr, size, KCSAN_ACCESS_ATOMIC) +#define kcsan_check_atomic_write(ptr, size) \ + kcsan_check_access(ptr, size, KCSAN_ACCESS_ATOMIC | KCSAN_ACCESS_WRITE) +#endif + +/** + * ASSERT_EXCLUSIVE_WRITER - assert no concurrent writes to @var + * + * Assert that there are no concurrent writes to @var; other readers are + * allowed. This assertion can be used to specify properties of concurrent code, + * where violation cannot be detected as a normal data race. + * + * For example, if we only have a single writer, but multiple concurrent + * readers, to avoid data races, all these accesses must be marked; even + * concurrent marked writes racing with the single writer are bugs. + * Unfortunately, due to being marked, they are no longer data races. For cases + * like these, we can use the macro as follows: + * + * .. code-block:: c + * + * void writer(void) { + * spin_lock(&update_foo_lock); + * ASSERT_EXCLUSIVE_WRITER(shared_foo); + * WRITE_ONCE(shared_foo, ...); + * spin_unlock(&update_foo_lock); + * } + * void reader(void) { + * // update_foo_lock does not need to be held! + * ... = READ_ONCE(shared_foo); + * } + * + * Note: ASSERT_EXCLUSIVE_WRITER_SCOPED(), if applicable, performs more thorough + * checking if a clear scope where no concurrent writes are expected exists. + * + * @var: variable to assert on + */ +#define ASSERT_EXCLUSIVE_WRITER(var) \ + __kcsan_check_access(&(var), sizeof(var), KCSAN_ACCESS_ASSERT) + +/* + * Helper macros for implementation of for ASSERT_EXCLUSIVE_*_SCOPED(). @id is + * expected to be unique for the scope in which instances of kcsan_scoped_access + * are declared. + */ +#define __kcsan_scoped_name(c, suffix) __kcsan_scoped_##c##suffix +#define __ASSERT_EXCLUSIVE_SCOPED(var, type, id) \ + struct kcsan_scoped_access __kcsan_scoped_name(id, _) \ + __kcsan_cleanup_scoped; \ + struct kcsan_scoped_access *__kcsan_scoped_name(id, _dummy_p) \ + __maybe_unused = kcsan_begin_scoped_access( \ + &(var), sizeof(var), KCSAN_ACCESS_SCOPED | (type), \ + &__kcsan_scoped_name(id, _)) + +/** + * ASSERT_EXCLUSIVE_WRITER_SCOPED - assert no concurrent writes to @var in scope + * + * Scoped variant of ASSERT_EXCLUSIVE_WRITER(). + * + * Assert that there are no concurrent writes to @var for the duration of the + * scope in which it is introduced. This provides a better way to fully cover + * the enclosing scope, compared to multiple ASSERT_EXCLUSIVE_WRITER(), and + * increases the likelihood for KCSAN to detect racing accesses. + * + * For example, it allows finding race-condition bugs that only occur due to + * state changes within the scope itself: + * + * .. code-block:: c + * + * void writer(void) { + * spin_lock(&update_foo_lock); + * { + * ASSERT_EXCLUSIVE_WRITER_SCOPED(shared_foo); + * WRITE_ONCE(shared_foo, 42); + * ... + * // shared_foo should still be 42 here! + * } + * spin_unlock(&update_foo_lock); + * } + * void buggy(void) { + * if (READ_ONCE(shared_foo) == 42) + * WRITE_ONCE(shared_foo, 1); // bug! + * } + * + * @var: variable to assert on + */ +#define ASSERT_EXCLUSIVE_WRITER_SCOPED(var) \ + __ASSERT_EXCLUSIVE_SCOPED(var, KCSAN_ACCESS_ASSERT, __COUNTER__) + +/** + * ASSERT_EXCLUSIVE_ACCESS - assert no concurrent accesses to @var + * + * Assert that there are no concurrent accesses to @var (no readers nor + * writers). This assertion can be used to specify properties of concurrent + * code, where violation cannot be detected as a normal data race. + * + * For example, where exclusive access is expected after determining no other + * users of an object are left, but the object is not actually freed. We can + * check that this property actually holds as follows: + * + * .. code-block:: c + * + * if (refcount_dec_and_test(&obj->refcnt)) { + * ASSERT_EXCLUSIVE_ACCESS(*obj); + * do_some_cleanup(obj); + * release_for_reuse(obj); + * } + * + * Note: ASSERT_EXCLUSIVE_ACCESS_SCOPED(), if applicable, performs more thorough + * checking if a clear scope where no concurrent accesses are expected exists. + * + * Note: For cases where the object is freed, `KASAN <kasan.html>`_ is a better + * fit to detect use-after-free bugs. + * + * @var: variable to assert on + */ +#define ASSERT_EXCLUSIVE_ACCESS(var) \ + __kcsan_check_access(&(var), sizeof(var), KCSAN_ACCESS_WRITE | KCSAN_ACCESS_ASSERT) + +/** + * ASSERT_EXCLUSIVE_ACCESS_SCOPED - assert no concurrent accesses to @var in scope + * + * Scoped variant of ASSERT_EXCLUSIVE_ACCESS(). + * + * Assert that there are no concurrent accesses to @var (no readers nor writers) + * for the entire duration of the scope in which it is introduced. This provides + * a better way to fully cover the enclosing scope, compared to multiple + * ASSERT_EXCLUSIVE_ACCESS(), and increases the likelihood for KCSAN to detect + * racing accesses. + * + * @var: variable to assert on + */ +#define ASSERT_EXCLUSIVE_ACCESS_SCOPED(var) \ + __ASSERT_EXCLUSIVE_SCOPED(var, KCSAN_ACCESS_WRITE | KCSAN_ACCESS_ASSERT, __COUNTER__) + +/** + * ASSERT_EXCLUSIVE_BITS - assert no concurrent writes to subset of bits in @var + * + * Bit-granular variant of ASSERT_EXCLUSIVE_WRITER(). + * + * Assert that there are no concurrent writes to a subset of bits in @var; + * concurrent readers are permitted. This assertion captures more detailed + * bit-level properties, compared to the other (word granularity) assertions. + * Only the bits set in @mask are checked for concurrent modifications, while + * ignoring the remaining bits, i.e. concurrent writes (or reads) to ~mask bits + * are ignored. + * + * Use this for variables, where some bits must not be modified concurrently, + * yet other bits are expected to be modified concurrently. + * + * For example, variables where, after initialization, some bits are read-only, + * but other bits may still be modified concurrently. A reader may wish to + * assert that this is true as follows: + * + * .. code-block:: c + * + * ASSERT_EXCLUSIVE_BITS(flags, READ_ONLY_MASK); + * foo = (READ_ONCE(flags) & READ_ONLY_MASK) >> READ_ONLY_SHIFT; + * + * Note: The access that immediately follows ASSERT_EXCLUSIVE_BITS() is assumed + * to access the masked bits only, and KCSAN optimistically assumes it is + * therefore safe, even in the presence of data races, and marking it with + * READ_ONCE() is optional from KCSAN's point-of-view. We caution, however, that + * it may still be advisable to do so, since we cannot reason about all compiler + * optimizations when it comes to bit manipulations (on the reader and writer + * side). If you are sure nothing can go wrong, we can write the above simply + * as: + * + * .. code-block:: c + * + * ASSERT_EXCLUSIVE_BITS(flags, READ_ONLY_MASK); + * foo = (flags & READ_ONLY_MASK) >> READ_ONLY_SHIFT; + * + * Another example, where this may be used, is when certain bits of @var may + * only be modified when holding the appropriate lock, but other bits may still + * be modified concurrently. Writers, where other bits may change concurrently, + * could use the assertion as follows: + * + * .. code-block:: c + * + * spin_lock(&foo_lock); + * ASSERT_EXCLUSIVE_BITS(flags, FOO_MASK); + * old_flags = flags; + * new_flags = (old_flags & ~FOO_MASK) | (new_foo << FOO_SHIFT); + * if (cmpxchg(&flags, old_flags, new_flags) != old_flags) { ... } + * spin_unlock(&foo_lock); + * + * @var: variable to assert on + * @mask: only check for modifications to bits set in @mask + */ +#define ASSERT_EXCLUSIVE_BITS(var, mask) \ + do { \ + kcsan_set_access_mask(mask); \ + __kcsan_check_access(&(var), sizeof(var), KCSAN_ACCESS_ASSERT);\ + kcsan_set_access_mask(0); \ + kcsan_atomic_next(1); \ + } while (0) + +#endif /* _LINUX_KCSAN_CHECKS_H */ diff --git a/include/linux/kcsan.h b/include/linux/kcsan.h new file mode 100644 index 000000000000..53340d8789f9 --- /dev/null +++ b/include/linux/kcsan.h @@ -0,0 +1,59 @@ +/* SPDX-License-Identifier: GPL-2.0 */ + +#ifndef _LINUX_KCSAN_H +#define _LINUX_KCSAN_H + +#include <linux/kcsan-checks.h> +#include <linux/types.h> + +#ifdef CONFIG_KCSAN + +/* + * Context for each thread of execution: for tasks, this is stored in + * task_struct, and interrupts access internal per-CPU storage. + */ +struct kcsan_ctx { + int disable_count; /* disable counter */ + int atomic_next; /* number of following atomic ops */ + + /* + * We distinguish between: (a) nestable atomic regions that may contain + * other nestable regions; and (b) flat atomic regions that do not keep + * track of nesting. Both (a) and (b) are entirely independent of each + * other, and a flat region may be started in a nestable region or + * vice-versa. + * + * This is required because, for example, in the annotations for + * seqlocks, we declare seqlock writer critical sections as (a) nestable + * atomic regions, but reader critical sections as (b) flat atomic + * regions, but have encountered cases where seqlock reader critical + * sections are contained within writer critical sections (the opposite + * may be possible, too). + * + * To support these cases, we independently track the depth of nesting + * for (a), and whether the leaf level is flat for (b). + */ + int atomic_nest_count; + bool in_flat_atomic; + + /* + * Access mask for all accesses if non-zero. + */ + unsigned long access_mask; + + /* List of scoped accesses. */ + struct list_head scoped_accesses; +}; + +/** + * kcsan_init - initialize KCSAN runtime + */ +void kcsan_init(void); + +#else /* CONFIG_KCSAN */ + +static inline void kcsan_init(void) { } + +#endif /* CONFIG_KCSAN */ + +#endif /* _LINUX_KCSAN_H */ diff --git a/include/linux/sched.h b/include/linux/sched.h index c5d96e3e7fff..4ea612e9ad27 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -31,6 +31,7 @@ #include <linux/task_io_accounting.h> #include <linux/posix-timers.h> #include <linux/rseq.h> +#include <linux/kcsan.h> /* task_struct member predeclarations (sorted alphabetically): */ struct audit_context; @@ -1197,6 +1198,9 @@ struct task_struct { #ifdef CONFIG_KASAN unsigned int kasan_depth; #endif +#ifdef CONFIG_KCSAN + struct kcsan_ctx kcsan_ctx; +#endif #ifdef CONFIG_FUNCTION_GRAPH_TRACER /* Index of current stored address in ret_stack: */ diff --git a/include/linux/seqlock.h b/include/linux/seqlock.h index 0491d963d47e..8b97204f35a7 100644 --- a/include/linux/seqlock.h +++ b/include/linux/seqlock.h @@ -37,9 +37,25 @@ #include <linux/preempt.h> #include <linux/lockdep.h> #include <linux/compiler.h> +#include <linux/kcsan-checks.h> #include <asm/processor.h> /* + * The seqlock interface does not prescribe a precise sequence of read + * begin/retry/end. For readers, typically there is a call to + * read_seqcount_begin() and read_seqcount_retry(), however, there are more + * esoteric cases which do not follow this pattern. + * + * As a consequence, we take the following best-effort approach for raw usage + * via seqcount_t under KCSAN: upon beginning a seq-reader critical section, + * pessimistically mark the next KCSAN_SEQLOCK_REGION_MAX memory accesses as + * atomics; if there is a matching read_seqcount_retry() call, no following + * memory operations are considered atomic. Usage of seqlocks via seqlock_t + * interface is not affected. + */ +#define KCSAN_SEQLOCK_REGION_MAX 1000 + +/* * Version using sequence counter only. * This can be used when code has its own mutex protecting the * updating starting before the write_seqcountbeqin() and ending @@ -115,6 +131,7 @@ repeat: cpu_relax(); goto repeat; } + kcsan_atomic_next(KCSAN_SEQLOCK_REGION_MAX); return ret; } @@ -131,6 +148,7 @@ static inline unsigned raw_read_seqcount(const seqcount_t *s) { unsigned ret = READ_ONCE(s->sequence); smp_rmb(); + kcsan_atomic_next(KCSAN_SEQLOCK_REGION_MAX); return ret; } @@ -183,6 +201,7 @@ static inline unsigned raw_seqcount_begin(const seqcount_t *s) { unsigned ret = READ_ONCE(s->sequence); smp_rmb(); + kcsan_atomic_next(KCSAN_SEQLOCK_REGION_MAX); return ret & ~1; } @@ -202,7 +221,8 @@ static inline unsigned raw_seqcount_begin(const seqcount_t *s) */ static inline int __read_seqcount_retry(const seqcount_t *s, unsigned start) { - return unlikely(s->sequence != start); + kcsan_atomic_next(0); + return unlikely(READ_ONCE(s->sequence) != start); } /** @@ -225,6 +245,7 @@ static inline int read_seqcount_retry(const seqcount_t *s, unsigned start) static inline void raw_write_seqcount_begin(seqcount_t *s) { + kcsan_nestable_atomic_begin(); s->sequence++; smp_wmb(); } @@ -233,6 +254,7 @@ static inline void raw_write_seqcount_end(seqcount_t *s) { smp_wmb(); s->sequence++; + kcsan_nestable_atomic_end(); } /** @@ -243,6 +265,13 @@ static inline void raw_write_seqcount_end(seqcount_t *s) * usual consistency guarantee. It is one wmb cheaper, because we can * collapse the two back-to-back wmb()s. * + * Note that writes surrounding the barrier should be declared atomic (e.g. + * via WRITE_ONCE): a) to ensure the writes become visible to other threads + * atomically, avoiding compiler optimizations; b) to document which writes are + * meant to propagate to the reader critical section. This is necessary because + * neither writes before and after the barrier are enclosed in a seq-writer + * critical section that would ensure readers are aware of ongoing writes. + * * seqcount_t seq; * bool X = true, Y = false; * @@ -262,18 +291,20 @@ static inline void raw_write_seqcount_end(seqcount_t *s) * * void write(void) * { - * Y = true; + * WRITE_ONCE(Y, true); * * raw_write_seqcount_barrier(seq); * - * X = false; + * WRITE_ONCE(X, false); * } */ static inline void raw_write_seqcount_barrier(seqcount_t *s) { + kcsan_nestable_atomic_begin(); s->sequence++; smp_wmb(); s->sequence++; + kcsan_nestable_atomic_end(); } static inline int raw_read_seqcount_latch(seqcount_t *s) @@ -398,7 +429,9 @@ static inline void write_seqcount_end(seqcount_t *s) static inline void write_seqcount_invalidate(seqcount_t *s) { smp_wmb(); + kcsan_nestable_atomic_begin(); s->sequence+=2; + kcsan_nestable_atomic_end(); } typedef struct { @@ -430,11 +463,21 @@ typedef struct { */ static inline unsigned read_seqbegin(const seqlock_t *sl) { - return read_seqcount_begin(&sl->seqcount); + unsigned ret = read_seqcount_begin(&sl->seqcount); + + kcsan_atomic_next(0); /* non-raw usage, assume closing read_seqretry() */ + kcsan_flat_atomic_begin(); + return ret; } static inline unsigned read_seqretry(const seqlock_t *sl, unsigned start) { + /* + * Assume not nested: read_seqretry() may be called multiple times when + * completing read critical section. + */ + kcsan_flat_atomic_end(); + return read_seqcount_retry(&sl->seqcount, start); } diff --git a/include/linux/uaccess.h b/include/linux/uaccess.h index dac1db05bf7e..7bcadca22100 100644 --- a/include/linux/uaccess.h +++ b/include/linux/uaccess.h @@ -2,9 +2,9 @@ #ifndef __LINUX_UACCESS_H__ #define __LINUX_UACCESS_H__ +#include <linux/instrumented.h> #include <linux/sched.h> #include <linux/thread_info.h> -#include <linux/kasan-checks.h> #define uaccess_kernel() segment_eq(get_fs(), KERNEL_DS) @@ -58,7 +58,7 @@ static __always_inline __must_check unsigned long __copy_from_user_inatomic(void *to, const void __user *from, unsigned long n) { - kasan_check_write(to, n); + instrument_copy_from_user(to, from, n); check_object_size(to, n, false); return raw_copy_from_user(to, from, n); } @@ -67,7 +67,7 @@ static __always_inline __must_check unsigned long __copy_from_user(void *to, const void __user *from, unsigned long n) { might_fault(); - kasan_check_write(to, n); + instrument_copy_from_user(to, from, n); check_object_size(to, n, false); return raw_copy_from_user(to, from, n); } @@ -88,7 +88,7 @@ __copy_from_user(void *to, const void __user *from, unsigned long n) static __always_inline __must_check unsigned long __copy_to_user_inatomic(void __user *to, const void *from, unsigned long n) { - kasan_check_read(from, n); + instrument_copy_to_user(to, from, n); check_object_size(from, n, true); return raw_copy_to_user(to, from, n); } @@ -97,7 +97,7 @@ static __always_inline __must_check unsigned long __copy_to_user(void __user *to, const void *from, unsigned long n) { might_fault(); - kasan_check_read(from, n); + instrument_copy_to_user(to, from, n); check_object_size(from, n, true); return raw_copy_to_user(to, from, n); } @@ -109,7 +109,7 @@ _copy_from_user(void *to, const void __user *from, unsigned long n) unsigned long res = n; might_fault(); if (likely(access_ok(from, n))) { - kasan_check_write(to, n); + instrument_copy_from_user(to, from, n); res = raw_copy_from_user(to, from, n); } if (unlikely(res)) @@ -127,7 +127,7 @@ _copy_to_user(void __user *to, const void *from, unsigned long n) { might_fault(); if (access_ok(to, n)) { - kasan_check_read(from, n); + instrument_copy_to_user(to, from, n); n = raw_copy_to_user(to, from, n); } return n; diff --git a/init/init_task.c b/init/init_task.c index a90ac70cc515..15089d15010a 100644 --- a/init/init_task.c +++ b/init/init_task.c @@ -174,6 +174,16 @@ struct task_struct init_task #ifdef CONFIG_KASAN .kasan_depth = 1, #endif +#ifdef CONFIG_KCSAN + .kcsan_ctx = { + .disable_count = 0, + .atomic_next = 0, + .atomic_nest_count = 0, + .in_flat_atomic = false, + .access_mask = 0, + .scoped_accesses = {LIST_POISON1, NULL}, + }, +#endif #ifdef CONFIG_TRACE_IRQFLAGS .softirqs_enabled = 1, #endif diff --git a/init/main.c b/init/main.c index b59e09353881..0ead83e86b5a 100644 --- a/init/main.c +++ b/init/main.c @@ -95,6 +95,7 @@ #include <linux/rodata_test.h> #include <linux/jump_label.h> #include <linux/mem_encrypt.h> +#include <linux/kcsan.h> #include <asm/io.h> #include <asm/bugs.h> @@ -1036,6 +1037,7 @@ asmlinkage __visible void __init start_kernel(void) acpi_subsystem_init(); arch_post_acpi_subsys_init(); sfi_init_late(); + kcsan_init(); /* Do the rest non-__init'ed, we're now alive */ arch_call_rest_init(); diff --git a/kernel/Makefile b/kernel/Makefile index c332eb9d4841..ce8716a04d0e 100644 --- a/kernel/Makefile +++ b/kernel/Makefile @@ -23,6 +23,9 @@ endif # Prevents flicker of uninteresting __do_softirq()/__local_bh_disable_ip() # in coverage traces. KCOV_INSTRUMENT_softirq.o := n +# Avoid KCSAN instrumentation in softirq ("No shared variables, all the data +# are CPU local" => assume no data races), to reduce overhead in interrupts. +KCSAN_SANITIZE_softirq.o = n # These are called from save_stack_trace() on slub debug path, # and produce insane amounts of uninteresting coverage. KCOV_INSTRUMENT_module.o := n @@ -31,6 +34,7 @@ KCOV_INSTRUMENT_stacktrace.o := n # Don't self-instrument. KCOV_INSTRUMENT_kcov.o := n KASAN_SANITIZE_kcov.o := n +KCSAN_SANITIZE_kcov.o := n CFLAGS_kcov.o := $(call cc-option, -fno-conserve-stack -fno-stack-protector) # cond_syscall is currently not LTO compatible @@ -103,6 +107,7 @@ obj-$(CONFIG_TRACEPOINTS) += trace/ obj-$(CONFIG_IRQ_WORK) += irq_work.o obj-$(CONFIG_CPU_PM) += cpu_pm.o obj-$(CONFIG_BPF) += bpf/ +obj-$(CONFIG_KCSAN) += kcsan/ obj-$(CONFIG_SHADOW_CALL_STACK) += scs.o obj-$(CONFIG_PERF_EVENTS) += events/ @@ -121,6 +126,7 @@ obj-$(CONFIG_SYSCTL_KUNIT_TEST) += sysctl-test.o obj-$(CONFIG_GCC_PLUGIN_STACKLEAK) += stackleak.o KASAN_SANITIZE_stackleak.o := n +KCSAN_SANITIZE_stackleak.o := n KCOV_INSTRUMENT_stackleak.o := n $(obj)/configs.o: $(obj)/config_data.gz diff --git a/kernel/kcsan/Makefile b/kernel/kcsan/Makefile new file mode 100644 index 000000000000..d4999b38d1be --- /dev/null +++ b/kernel/kcsan/Makefile @@ -0,0 +1,14 @@ +# SPDX-License-Identifier: GPL-2.0 +KCSAN_SANITIZE := n +KCOV_INSTRUMENT := n +UBSAN_SANITIZE := n + +CFLAGS_REMOVE_core.o = $(CC_FLAGS_FTRACE) +CFLAGS_REMOVE_debugfs.o = $(CC_FLAGS_FTRACE) +CFLAGS_REMOVE_report.o = $(CC_FLAGS_FTRACE) + +CFLAGS_core.o := $(call cc-option,-fno-conserve-stack,) \ + $(call cc-option,-fno-stack-protector,) + +obj-y := core.o debugfs.o report.o +obj-$(CONFIG_KCSAN_SELFTEST) += test.o diff --git a/kernel/kcsan/atomic.h b/kernel/kcsan/atomic.h new file mode 100644 index 000000000000..be9e625227f3 --- /dev/null +++ b/kernel/kcsan/atomic.h @@ -0,0 +1,20 @@ +/* SPDX-License-Identifier: GPL-2.0 */ + +#ifndef _KERNEL_KCSAN_ATOMIC_H +#define _KERNEL_KCSAN_ATOMIC_H + +#include <linux/jiffies.h> +#include <linux/sched.h> + +/* + * Special rules for certain memory where concurrent conflicting accesses are + * common, however, the current convention is to not mark them; returns true if + * access to @ptr should be considered atomic. Called from slow-path. + */ +static bool kcsan_is_atomic_special(const volatile void *ptr) +{ + /* volatile globals that have been observed in data races. */ + return ptr == &jiffies || ptr == ¤t->state; +} + +#endif /* _KERNEL_KCSAN_ATOMIC_H */ diff --git a/kernel/kcsan/core.c b/kernel/kcsan/core.c new file mode 100644 index 000000000000..a73a66cf79df --- /dev/null +++ b/kernel/kcsan/core.c @@ -0,0 +1,807 @@ +// SPDX-License-Identifier: GPL-2.0 + +#include <linux/atomic.h> +#include <linux/bug.h> +#include <linux/delay.h> +#include <linux/export.h> +#include <linux/init.h> +#include <linux/kernel.h> +#include <linux/list.h> +#include <linux/moduleparam.h> +#include <linux/percpu.h> +#include <linux/preempt.h> +#include <linux/random.h> +#include <linux/sched.h> +#include <linux/uaccess.h> + +#include "atomic.h" +#include "encoding.h" +#include "kcsan.h" + +static bool kcsan_early_enable = IS_ENABLED(CONFIG_KCSAN_EARLY_ENABLE); +unsigned int kcsan_udelay_task = CONFIG_KCSAN_UDELAY_TASK; +unsigned int kcsan_udelay_interrupt = CONFIG_KCSAN_UDELAY_INTERRUPT; +static long kcsan_skip_watch = CONFIG_KCSAN_SKIP_WATCH; +static bool kcsan_interrupt_watcher = IS_ENABLED(CONFIG_KCSAN_INTERRUPT_WATCHER); + +#ifdef MODULE_PARAM_PREFIX +#undef MODULE_PARAM_PREFIX +#endif +#define MODULE_PARAM_PREFIX "kcsan." +module_param_named(early_enable, kcsan_early_enable, bool, 0); +module_param_named(udelay_task, kcsan_udelay_task, uint, 0644); +module_param_named(udelay_interrupt, kcsan_udelay_interrupt, uint, 0644); +module_param_named(skip_watch, kcsan_skip_watch, long, 0644); +module_param_named(interrupt_watcher, kcsan_interrupt_watcher, bool, 0444); + +bool kcsan_enabled; + +/* Per-CPU kcsan_ctx for interrupts */ +static DEFINE_PER_CPU(struct kcsan_ctx, kcsan_cpu_ctx) = { + .disable_count = 0, + .atomic_next = 0, + .atomic_nest_count = 0, + .in_flat_atomic = false, + .access_mask = 0, + .scoped_accesses = {LIST_POISON1, NULL}, +}; + +/* + * Helper macros to index into adjacent slots, starting from address slot + * itself, followed by the right and left slots. + * + * The purpose is 2-fold: + * + * 1. if during insertion the address slot is already occupied, check if + * any adjacent slots are free; + * 2. accesses that straddle a slot boundary due to size that exceeds a + * slot's range may check adjacent slots if any watchpoint matches. + * + * Note that accesses with very large size may still miss a watchpoint; however, + * given this should be rare, this is a reasonable trade-off to make, since this + * will avoid: + * + * 1. excessive contention between watchpoint checks and setup; + * 2. larger number of simultaneous watchpoints without sacrificing + * performance. + * + * Example: SLOT_IDX values for KCSAN_CHECK_ADJACENT=1, where i is [0, 1, 2]: + * + * slot=0: [ 1, 2, 0] + * slot=9: [10, 11, 9] + * slot=63: [64, 65, 63] + */ +#define SLOT_IDX(slot, i) (slot + ((i + KCSAN_CHECK_ADJACENT) % NUM_SLOTS)) + +/* + * SLOT_IDX_FAST is used in the fast-path. Not first checking the address's primary + * slot (middle) is fine if we assume that races occur rarely. The set of + * indices {SLOT_IDX(slot, i) | i in [0, NUM_SLOTS)} is equivalent to + * {SLOT_IDX_FAST(slot, i) | i in [0, NUM_SLOTS)}. + */ +#define SLOT_IDX_FAST(slot, i) (slot + i) + +/* + * Watchpoints, with each entry encoded as defined in encoding.h: in order to be + * able to safely update and access a watchpoint without introducing locking + * overhead, we encode each watchpoint as a single atomic long. The initial + * zero-initialized state matches INVALID_WATCHPOINT. + * + * Add NUM_SLOTS-1 entries to account for overflow; this helps avoid having to + * use more complicated SLOT_IDX_FAST calculation with modulo in the fast-path. + */ +static atomic_long_t watchpoints[CONFIG_KCSAN_NUM_WATCHPOINTS + NUM_SLOTS-1]; + +/* + * Instructions to skip watching counter, used in should_watch(). We use a + * per-CPU counter to avoid excessive contention. + */ +static DEFINE_PER_CPU(long, kcsan_skip); + +static __always_inline atomic_long_t *find_watchpoint(unsigned long addr, + size_t size, + bool expect_write, + long *encoded_watchpoint) +{ + const int slot = watchpoint_slot(addr); + const unsigned long addr_masked = addr & WATCHPOINT_ADDR_MASK; + atomic_long_t *watchpoint; + unsigned long wp_addr_masked; + size_t wp_size; + bool is_write; + int i; + + BUILD_BUG_ON(CONFIG_KCSAN_NUM_WATCHPOINTS < NUM_SLOTS); + + for (i = 0; i < NUM_SLOTS; ++i) { + watchpoint = &watchpoints[SLOT_IDX_FAST(slot, i)]; + *encoded_watchpoint = atomic_long_read(watchpoint); + if (!decode_watchpoint(*encoded_watchpoint, &wp_addr_masked, + &wp_size, &is_write)) + continue; + + if (expect_write && !is_write) + continue; + + /* Check if the watchpoint matches the access. */ + if (matching_access(wp_addr_masked, wp_size, addr_masked, size)) + return watchpoint; + } + + return NULL; +} + +static inline atomic_long_t * +insert_watchpoint(unsigned long addr, size_t size, bool is_write) +{ + const int slot = watchpoint_slot(addr); + const long encoded_watchpoint = encode_watchpoint(addr, size, is_write); + atomic_long_t *watchpoint; + int i; + + /* Check slot index logic, ensuring we stay within array bounds. */ + BUILD_BUG_ON(SLOT_IDX(0, 0) != KCSAN_CHECK_ADJACENT); + BUILD_BUG_ON(SLOT_IDX(0, KCSAN_CHECK_ADJACENT+1) != 0); + BUILD_BUG_ON(SLOT_IDX(CONFIG_KCSAN_NUM_WATCHPOINTS-1, KCSAN_CHECK_ADJACENT) != ARRAY_SIZE(watchpoints)-1); + BUILD_BUG_ON(SLOT_IDX(CONFIG_KCSAN_NUM_WATCHPOINTS-1, KCSAN_CHECK_ADJACENT+1) != ARRAY_SIZE(watchpoints) - NUM_SLOTS); + + for (i = 0; i < NUM_SLOTS; ++i) { + long expect_val = INVALID_WATCHPOINT; + + /* Try to acquire this slot. */ + watchpoint = &watchpoints[SLOT_IDX(slot, i)]; + if (atomic_long_try_cmpxchg_relaxed(watchpoint, &expect_val, encoded_watchpoint)) + return watchpoint; + } + + return NULL; +} + +/* + * Return true if watchpoint was successfully consumed, false otherwise. + * + * This may return false if: + * + * 1. another thread already consumed the watchpoint; + * 2. the thread that set up the watchpoint already removed it; + * 3. the watchpoint was removed and then re-used. + */ +static __always_inline bool +try_consume_watchpoint(atomic_long_t *watchpoint, long encoded_watchpoint) +{ + return atomic_long_try_cmpxchg_relaxed(watchpoint, &encoded_watchpoint, CONSUMED_WATCHPOINT); +} + +/* Return true if watchpoint was not touched, false if already consumed. */ +static inline bool consume_watchpoint(atomic_long_t *watchpoint) +{ + return atomic_long_xchg_relaxed(watchpoint, CONSUMED_WATCHPOINT) != CONSUMED_WATCHPOINT; +} + +/* Remove the watchpoint -- its slot may be reused after. */ +static inline void remove_watchpoint(atomic_long_t *watchpoint) +{ + atomic_long_set(watchpoint, INVALID_WATCHPOINT); +} + +static __always_inline struct kcsan_ctx *get_ctx(void) +{ + /* + * In interrupts, use raw_cpu_ptr to avoid unnecessary checks, that would + * also result in calls that generate warnings in uaccess regions. + */ + return in_task() ? ¤t->kcsan_ctx : raw_cpu_ptr(&kcsan_cpu_ctx); +} + +/* Check scoped accesses; never inline because this is a slow-path! */ +static noinline void kcsan_check_scoped_accesses(void) +{ + struct kcsan_ctx *ctx = get_ctx(); + struct list_head *prev_save = ctx->scoped_accesses.prev; + struct kcsan_scoped_access *scoped_access; + + ctx->scoped_accesses.prev = NULL; /* Avoid recursion. */ + list_for_each_entry(scoped_access, &ctx->scoped_accesses, list) + __kcsan_check_access(scoped_access->ptr, scoped_access->size, scoped_access->type); + ctx->scoped_accesses.prev = prev_save; +} + +/* Rules for generic atomic accesses. Called from fast-path. */ +static __always_inline bool +is_atomic(const volatile void *ptr, size_t size, int type, struct kcsan_ctx *ctx) +{ + if (type & KCSAN_ACCESS_ATOMIC) + return true; + + /* + * Unless explicitly declared atomic, never consider an assertion access + * as atomic. This allows using them also in atomic regions, such as + * seqlocks, without implicitly changing their semantics. + */ + if (type & KCSAN_ACCESS_ASSERT) + return false; + + if (IS_ENABLED(CONFIG_KCSAN_ASSUME_PLAIN_WRITES_ATOMIC) && + (type & KCSAN_ACCESS_WRITE) && size <= sizeof(long) && + IS_ALIGNED((unsigned long)ptr, size)) + return true; /* Assume aligned writes up to word size are atomic. */ + + if (ctx->atomic_next > 0) { + /* + * Because we do not have separate contexts for nested + * interrupts, in case atomic_next is set, we simply assume that + * the outer interrupt set atomic_next. In the worst case, we + * will conservatively consider operations as atomic. This is a + * reasonable trade-off to make, since this case should be + * extremely rare; however, even if extremely rare, it could + * lead to false positives otherwise. + */ + if ((hardirq_count() >> HARDIRQ_SHIFT) < 2) + --ctx->atomic_next; /* in task, or outer interrupt */ + return true; + } + + return ctx->atomic_nest_count > 0 || ctx->in_flat_atomic; +} + +static __always_inline bool +should_watch(const volatile void *ptr, size_t size, int type, struct kcsan_ctx *ctx) +{ + /* + * Never set up watchpoints when memory operations are atomic. + * + * Need to check this first, before kcsan_skip check below: (1) atomics + * should not count towards skipped instructions, and (2) to actually + * decrement kcsan_atomic_next for consecutive instruction stream. + */ + if (is_atomic(ptr, size, type, ctx)) + return false; + + if (this_cpu_dec_return(kcsan_skip) >= 0) + return false; + + /* + * NOTE: If we get here, kcsan_skip must always be reset in slow path + * via reset_kcsan_skip() to avoid underflow. + */ + + /* this operation should be watched */ + return true; +} + +static inline void reset_kcsan_skip(void) +{ + long skip_count = kcsan_skip_watch - + (IS_ENABLED(CONFIG_KCSAN_SKIP_WATCH_RANDOMIZE) ? + prandom_u32_max(kcsan_skip_watch) : + 0); + this_cpu_write(kcsan_skip, skip_count); +} + +static __always_inline bool kcsan_is_enabled(void) +{ + return READ_ONCE(kcsan_enabled) && get_ctx()->disable_count == 0; +} + +static inline unsigned int get_delay(void) +{ + unsigned int delay = in_task() ? kcsan_udelay_task : kcsan_udelay_interrupt; + return delay - (IS_ENABLED(CONFIG_KCSAN_DELAY_RANDOMIZE) ? + prandom_u32_max(delay) : + 0); +} + +/* + * Pull everything together: check_access() below contains the performance + * critical operations; the fast-path (including check_access) functions should + * all be inlinable by the instrumentation functions. + * + * The slow-path (kcsan_found_watchpoint, kcsan_setup_watchpoint) are + * non-inlinable -- note that, we prefix these with "kcsan_" to ensure they can + * be filtered from the stacktrace, as well as give them unique names for the + * UACCESS whitelist of objtool. Each function uses user_access_save/restore(), + * since they do not access any user memory, but instrumentation is still + * emitted in UACCESS regions. + */ + +static noinline void kcsan_found_watchpoint(const volatile void *ptr, + size_t size, + int type, + atomic_long_t *watchpoint, + long encoded_watchpoint) +{ + unsigned long flags; + bool consumed; + + if (!kcsan_is_enabled()) + return; + + /* + * The access_mask check relies on value-change comparison. To avoid + * reporting a race where e.g. the writer set up the watchpoint, but the + * reader has access_mask!=0, we have to ignore the found watchpoint. + */ + if (get_ctx()->access_mask != 0) + return; + + /* + * Consume the watchpoint as soon as possible, to minimize the chances + * of !consumed. Consuming the watchpoint must always be guarded by + * kcsan_is_enabled() check, as otherwise we might erroneously + * triggering reports when disabled. + */ + consumed = try_consume_watchpoint(watchpoint, encoded_watchpoint); + + /* keep this after try_consume_watchpoint */ + flags = user_access_save(); + + if (consumed) { + kcsan_report(ptr, size, type, KCSAN_VALUE_CHANGE_MAYBE, + KCSAN_REPORT_CONSUMED_WATCHPOINT, + watchpoint - watchpoints); + } else { + /* + * The other thread may not print any diagnostics, as it has + * already removed the watchpoint, or another thread consumed + * the watchpoint before this thread. + */ + kcsan_counter_inc(KCSAN_COUNTER_REPORT_RACES); + } + + if ((type & KCSAN_ACCESS_ASSERT) != 0) + kcsan_counter_inc(KCSAN_COUNTER_ASSERT_FAILURES); + else + kcsan_counter_inc(KCSAN_COUNTER_DATA_RACES); + + user_access_restore(flags); +} + +static noinline void +kcsan_setup_watchpoint(const volatile void *ptr, size_t size, int type) +{ + const bool is_write = (type & KCSAN_ACCESS_WRITE) != 0; + const bool is_assert = (type & KCSAN_ACCESS_ASSERT) != 0; + atomic_long_t *watchpoint; + union { + u8 _1; + u16 _2; + u32 _4; + u64 _8; + } expect_value; + unsigned long access_mask; + enum kcsan_value_change value_change = KCSAN_VALUE_CHANGE_MAYBE; + unsigned long ua_flags = user_access_save(); + unsigned long irq_flags = 0; + + /* + * Always reset kcsan_skip counter in slow-path to avoid underflow; see + * should_watch(). + */ + reset_kcsan_skip(); + + if (!kcsan_is_enabled()) + goto out; + + /* + * Special atomic rules: unlikely to be true, so we check them here in + * the slow-path, and not in the fast-path in is_atomic(). Call after + * kcsan_is_enabled(), as we may access memory that is not yet + * initialized during early boot. + */ + if (!is_assert && kcsan_is_atomic_special(ptr)) + goto out; + + if (!check_encodable((unsigned long)ptr, size)) { + kcsan_counter_inc(KCSAN_COUNTER_UNENCODABLE_ACCESSES); + goto out; + } + + if (!kcsan_interrupt_watcher) + /* Use raw to avoid lockdep recursion via IRQ flags tracing. */ + raw_local_irq_save(irq_flags); + + watchpoint = insert_watchpoint((unsigned long)ptr, size, is_write); + if (watchpoint == NULL) { + /* + * Out of capacity: the size of 'watchpoints', and the frequency + * with which should_watch() returns true should be tweaked so + * that this case happens very rarely. + */ + kcsan_counter_inc(KCSAN_COUNTER_NO_CAPACITY); + goto out_unlock; + } + + kcsan_counter_inc(KCSAN_COUNTER_SETUP_WATCHPOINTS); + kcsan_counter_inc(KCSAN_COUNTER_USED_WATCHPOINTS); + + /* + * Read the current value, to later check and infer a race if the data + * was modified via a non-instrumented access, e.g. from a device. + */ + expect_value._8 = 0; + switch (size) { + case 1: + expect_value._1 = READ_ONCE(*(const u8 *)ptr); + break; + case 2: + expect_value._2 = READ_ONCE(*(const u16 *)ptr); + break; + case 4: + expect_value._4 = READ_ONCE(*(const u32 *)ptr); + break; + case 8: + expect_value._8 = READ_ONCE(*(const u64 *)ptr); + break; + default: + break; /* ignore; we do not diff the values */ + } + + if (IS_ENABLED(CONFIG_KCSAN_DEBUG)) { + kcsan_disable_current(); + pr_err("KCSAN: watching %s, size: %zu, addr: %px [slot: %d, encoded: %lx]\n", + is_write ? "write" : "read", size, ptr, + watchpoint_slot((unsigned long)ptr), + encode_watchpoint((unsigned long)ptr, size, is_write)); + kcsan_enable_current(); + } + + /* + * Delay this thread, to increase probability of observing a racy + * conflicting access. + */ + udelay(get_delay()); + + /* + * Re-read value, and check if it is as expected; if not, we infer a + * racy access. + */ + access_mask = get_ctx()->access_mask; + switch (size) { + case 1: + expect_value._1 ^= READ_ONCE(*(const u8 *)ptr); + if (access_mask) + expect_value._1 &= (u8)access_mask; + break; + case 2: + expect_value._2 ^= READ_ONCE(*(const u16 *)ptr); + if (access_mask) + expect_value._2 &= (u16)access_mask; + break; + case 4: + expect_value._4 ^= READ_ONCE(*(const u32 *)ptr); + if (access_mask) + expect_value._4 &= (u32)access_mask; + break; + case 8: + expect_value._8 ^= READ_ONCE(*(const u64 *)ptr); + if (access_mask) + expect_value._8 &= (u64)access_mask; + break; + default: + break; /* ignore; we do not diff the values */ + } + + /* Were we able to observe a value-change? */ + if (expect_value._8 != 0) + value_change = KCSAN_VALUE_CHANGE_TRUE; + + /* Check if this access raced with another. */ + if (!consume_watchpoint(watchpoint)) { + /* + * Depending on the access type, map a value_change of MAYBE to + * TRUE (always report) or FALSE (never report). + */ + if (value_change == KCSAN_VALUE_CHANGE_MAYBE) { + if (access_mask != 0) { + /* + * For access with access_mask, we require a + * value-change, as it is likely that races on + * ~access_mask bits are expected. + */ + value_change = KCSAN_VALUE_CHANGE_FALSE; + } else if (size > 8 || is_assert) { + /* Always assume a value-change. */ + value_change = KCSAN_VALUE_CHANGE_TRUE; + } + } + + /* + * No need to increment 'data_races' counter, as the racing + * thread already did. + * + * Count 'assert_failures' for each failed ASSERT access, + * therefore both this thread and the racing thread may + * increment this counter. + */ + if (is_assert && value_change == KCSAN_VALUE_CHANGE_TRUE) + kcsan_counter_inc(KCSAN_COUNTER_ASSERT_FAILURES); + + kcsan_report(ptr, size, type, value_change, KCSAN_REPORT_RACE_SIGNAL, + watchpoint - watchpoints); + } else if (value_change == KCSAN_VALUE_CHANGE_TRUE) { + /* Inferring a race, since the value should not have changed. */ + + kcsan_counter_inc(KCSAN_COUNTER_RACES_UNKNOWN_ORIGIN); + if (is_assert) + kcsan_counter_inc(KCSAN_COUNTER_ASSERT_FAILURES); + + if (IS_ENABLED(CONFIG_KCSAN_REPORT_RACE_UNKNOWN_ORIGIN) || is_assert) + kcsan_report(ptr, size, type, KCSAN_VALUE_CHANGE_TRUE, + KCSAN_REPORT_RACE_UNKNOWN_ORIGIN, + watchpoint - watchpoints); + } + + /* + * Remove watchpoint; must be after reporting, since the slot may be + * reused after this point. + */ + remove_watchpoint(watchpoint); + kcsan_counter_dec(KCSAN_COUNTER_USED_WATCHPOINTS); +out_unlock: + if (!kcsan_interrupt_watcher) + raw_local_irq_restore(irq_flags); +out: + user_access_restore(ua_flags); +} + +static __always_inline void check_access(const volatile void *ptr, size_t size, + int type) +{ + const bool is_write = (type & KCSAN_ACCESS_WRITE) != 0; + atomic_long_t *watchpoint; + long encoded_watchpoint; + + /* + * Do nothing for 0 sized check; this comparison will be optimized out + * for constant sized instrumentation (__tsan_{read,write}N). + */ + if (unlikely(size == 0)) + return; + + /* + * Avoid user_access_save in fast-path: find_watchpoint is safe without + * user_access_save, as the address that ptr points to is only used to + * check if a watchpoint exists; ptr is never dereferenced. + */ + watchpoint = find_watchpoint((unsigned long)ptr, size, !is_write, + &encoded_watchpoint); + /* + * It is safe to check kcsan_is_enabled() after find_watchpoint in the + * slow-path, as long as no state changes that cause a race to be + * detected and reported have occurred until kcsan_is_enabled() is + * checked. + */ + + if (unlikely(watchpoint != NULL)) + kcsan_found_watchpoint(ptr, size, type, watchpoint, + encoded_watchpoint); + else { + struct kcsan_ctx *ctx = get_ctx(); /* Call only once in fast-path. */ + + if (unlikely(should_watch(ptr, size, type, ctx))) + kcsan_setup_watchpoint(ptr, size, type); + else if (unlikely(ctx->scoped_accesses.prev)) + kcsan_check_scoped_accesses(); + } +} + +/* === Public interface ===================================================== */ + +void __init kcsan_init(void) +{ + BUG_ON(!in_task()); + + kcsan_debugfs_init(); + + /* + * We are in the init task, and no other tasks should be running; + * WRITE_ONCE without memory barrier is sufficient. + */ + if (kcsan_early_enable) + WRITE_ONCE(kcsan_enabled, true); +} + +/* === Exported interface =================================================== */ + +void kcsan_disable_current(void) +{ + ++get_ctx()->disable_count; +} +EXPORT_SYMBOL(kcsan_disable_current); + +void kcsan_enable_current(void) +{ + if (get_ctx()->disable_count-- == 0) { + /* + * Warn if kcsan_enable_current() calls are unbalanced with + * kcsan_disable_current() calls, which causes disable_count to + * become negative and should not happen. + */ + kcsan_disable_current(); /* restore to 0, KCSAN still enabled */ + kcsan_disable_current(); /* disable to generate warning */ + WARN(1, "Unbalanced %s()", __func__); + kcsan_enable_current(); + } +} +EXPORT_SYMBOL(kcsan_enable_current); + +void kcsan_enable_current_nowarn(void) +{ + if (get_ctx()->disable_count-- == 0) + kcsan_disable_current(); +} +EXPORT_SYMBOL(kcsan_enable_current_nowarn); + +void kcsan_nestable_atomic_begin(void) +{ + /* + * Do *not* check and warn if we are in a flat atomic region: nestable + * and flat atomic regions are independent from each other. + * See include/linux/kcsan.h: struct kcsan_ctx comments for more + * comments. + */ + + ++get_ctx()->atomic_nest_count; +} +EXPORT_SYMBOL(kcsan_nestable_atomic_begin); + +void kcsan_nestable_atomic_end(void) +{ + if (get_ctx()->atomic_nest_count-- == 0) { + /* + * Warn if kcsan_nestable_atomic_end() calls are unbalanced with + * kcsan_nestable_atomic_begin() calls, which causes + * atomic_nest_count to become negative and should not happen. + */ + kcsan_nestable_atomic_begin(); /* restore to 0 */ + kcsan_disable_current(); /* disable to generate warning */ + WARN(1, "Unbalanced %s()", __func__); + kcsan_enable_current(); + } +} +EXPORT_SYMBOL(kcsan_nestable_atomic_end); + +void kcsan_flat_atomic_begin(void) +{ + get_ctx()->in_flat_atomic = true; +} +EXPORT_SYMBOL(kcsan_flat_atomic_begin); + +void kcsan_flat_atomic_end(void) +{ + get_ctx()->in_flat_atomic = false; +} +EXPORT_SYMBOL(kcsan_flat_atomic_end); + +void kcsan_atomic_next(int n) +{ + get_ctx()->atomic_next = n; +} +EXPORT_SYMBOL(kcsan_atomic_next); + +void kcsan_set_access_mask(unsigned long mask) +{ + get_ctx()->access_mask = mask; +} +EXPORT_SYMBOL(kcsan_set_access_mask); + +struct kcsan_scoped_access * +kcsan_begin_scoped_access(const volatile void *ptr, size_t size, int type, + struct kcsan_scoped_access *sa) +{ + struct kcsan_ctx *ctx = get_ctx(); + + __kcsan_check_access(ptr, size, type); + + ctx->disable_count++; /* Disable KCSAN, in case list debugging is on. */ + + INIT_LIST_HEAD(&sa->list); + sa->ptr = ptr; + sa->size = size; + sa->type = type; + + if (!ctx->scoped_accesses.prev) /* Lazy initialize list head. */ + INIT_LIST_HEAD(&ctx->scoped_accesses); + list_add(&sa->list, &ctx->scoped_accesses); + + ctx->disable_count--; + return sa; +} +EXPORT_SYMBOL(kcsan_begin_scoped_access); + +void kcsan_end_scoped_access(struct kcsan_scoped_access *sa) +{ + struct kcsan_ctx *ctx = get_ctx(); + + if (WARN(!ctx->scoped_accesses.prev, "Unbalanced %s()?", __func__)) + return; + + ctx->disable_count++; /* Disable KCSAN, in case list debugging is on. */ + + list_del(&sa->list); + if (list_empty(&ctx->scoped_accesses)) + /* + * Ensure we do not enter kcsan_check_scoped_accesses() + * slow-path if unnecessary, and avoids requiring list_empty() + * in the fast-path (to avoid a READ_ONCE() and potential + * uaccess warning). + */ + ctx->scoped_accesses.prev = NULL; + + ctx->disable_count--; + + __kcsan_check_access(sa->ptr, sa->size, sa->type); +} +EXPORT_SYMBOL(kcsan_end_scoped_access); + +void __kcsan_check_access(const volatile void *ptr, size_t size, int type) +{ + check_access(ptr, size, type); +} +EXPORT_SYMBOL(__kcsan_check_access); + +/* + * KCSAN uses the same instrumentation that is emitted by supported compilers + * for ThreadSanitizer (TSAN). + * + * When enabled, the compiler emits instrumentation calls (the functions + * prefixed with "__tsan" below) for all loads and stores that it generated; + * inline asm is not instrumented. + * + * Note that, not all supported compiler versions distinguish aligned/unaligned + * accesses, but e.g. recent versions of Clang do. We simply alias the unaligned + * version to the generic version, which can handle both. + */ + +#define DEFINE_TSAN_READ_WRITE(size) \ + void __tsan_read##size(void *ptr) \ + { \ + check_access(ptr, size, 0); \ + } \ + EXPORT_SYMBOL(__tsan_read##size); \ + void __tsan_unaligned_read##size(void *ptr) \ + __alias(__tsan_read##size); \ + EXPORT_SYMBOL(__tsan_unaligned_read##size); \ + void __tsan_write##size(void *ptr) \ + { \ + check_access(ptr, size, KCSAN_ACCESS_WRITE); \ + } \ + EXPORT_SYMBOL(__tsan_write##size); \ + void __tsan_unaligned_write##size(void *ptr) \ + __alias(__tsan_write##size); \ + EXPORT_SYMBOL(__tsan_unaligned_write##size) + +DEFINE_TSAN_READ_WRITE(1); +DEFINE_TSAN_READ_WRITE(2); +DEFINE_TSAN_READ_WRITE(4); +DEFINE_TSAN_READ_WRITE(8); +DEFINE_TSAN_READ_WRITE(16); + +void __tsan_read_range(void *ptr, size_t size) +{ + check_access(ptr, size, 0); +} +EXPORT_SYMBOL(__tsan_read_range); + +void __tsan_write_range(void *ptr, size_t size) +{ + check_access(ptr, size, KCSAN_ACCESS_WRITE); +} +EXPORT_SYMBOL(__tsan_write_range); + +/* + * The below are not required by KCSAN, but can still be emitted by the + * compiler. + */ +void __tsan_func_entry(void *call_pc) +{ +} +EXPORT_SYMBOL(__tsan_func_entry); +void __tsan_func_exit(void) +{ +} +EXPORT_SYMBOL(__tsan_func_exit); +void __tsan_init(void) +{ +} +EXPORT_SYMBOL(__tsan_init); diff --git a/kernel/kcsan/debugfs.c b/kernel/kcsan/debugfs.c new file mode 100644 index 000000000000..023e49c58d55 --- /dev/null +++ b/kernel/kcsan/debugfs.c @@ -0,0 +1,349 @@ +// SPDX-License-Identifier: GPL-2.0 + +#include <linux/atomic.h> +#include <linux/bsearch.h> +#include <linux/bug.h> +#include <linux/debugfs.h> +#include <linux/init.h> +#include <linux/kallsyms.h> +#include <linux/sched.h> +#include <linux/seq_file.h> +#include <linux/slab.h> +#include <linux/sort.h> +#include <linux/string.h> +#include <linux/uaccess.h> + +#include "kcsan.h" + +/* + * Statistics counters. + */ +static atomic_long_t counters[KCSAN_COUNTER_COUNT]; + +/* + * Addresses for filtering functions from reporting. This list can be used as a + * whitelist or blacklist. + */ +static struct { + unsigned long *addrs; /* array of addresses */ + size_t size; /* current size */ + int used; /* number of elements used */ + bool sorted; /* if elements are sorted */ + bool whitelist; /* if list is a blacklist or whitelist */ +} report_filterlist = { + .addrs = NULL, + .size = 8, /* small initial size */ + .used = 0, + .sorted = false, + .whitelist = false, /* default is blacklist */ +}; +static DEFINE_SPINLOCK(report_filterlist_lock); + +static const char *counter_to_name(enum kcsan_counter_id id) +{ + switch (id) { + case KCSAN_COUNTER_USED_WATCHPOINTS: return "used_watchpoints"; + case KCSAN_COUNTER_SETUP_WATCHPOINTS: return "setup_watchpoints"; + case KCSAN_COUNTER_DATA_RACES: return "data_races"; + case KCSAN_COUNTER_ASSERT_FAILURES: return "assert_failures"; + case KCSAN_COUNTER_NO_CAPACITY: return "no_capacity"; + case KCSAN_COUNTER_REPORT_RACES: return "report_races"; + case KCSAN_COUNTER_RACES_UNKNOWN_ORIGIN: return "races_unknown_origin"; + case KCSAN_COUNTER_UNENCODABLE_ACCESSES: return "unencodable_accesses"; + case KCSAN_COUNTER_ENCODING_FALSE_POSITIVES: return "encoding_false_positives"; + case KCSAN_COUNTER_COUNT: + BUG(); + } + return NULL; +} + +void kcsan_counter_inc(enum kcsan_counter_id id) +{ + atomic_long_inc(&counters[id]); +} + +void kcsan_counter_dec(enum kcsan_counter_id id) +{ + atomic_long_dec(&counters[id]); +} + +/* + * The microbenchmark allows benchmarking KCSAN core runtime only. To run + * multiple threads, pipe 'microbench=<iters>' from multiple tasks into the + * debugfs file. This will not generate any conflicts, and tests fast-path only. + */ +static noinline void microbenchmark(unsigned long iters) +{ + const struct kcsan_ctx ctx_save = current->kcsan_ctx; + const bool was_enabled = READ_ONCE(kcsan_enabled); + cycles_t cycles; + + /* We may have been called from an atomic region; reset context. */ + memset(¤t->kcsan_ctx, 0, sizeof(current->kcsan_ctx)); + /* + * Disable to benchmark fast-path for all accesses, and (expected + * negligible) call into slow-path, but never set up watchpoints. + */ + WRITE_ONCE(kcsan_enabled, false); + + pr_info("KCSAN: %s begin | iters: %lu\n", __func__, iters); + + cycles = get_cycles(); + while (iters--) { + unsigned long addr = iters & ((PAGE_SIZE << 8) - 1); + int type = !(iters & 0x7f) ? KCSAN_ACCESS_ATOMIC : + (!(iters & 0xf) ? KCSAN_ACCESS_WRITE : 0); + __kcsan_check_access((void *)addr, sizeof(long), type); + } + cycles = get_cycles() - cycles; + + pr_info("KCSAN: %s end | cycles: %llu\n", __func__, cycles); + + WRITE_ONCE(kcsan_enabled, was_enabled); + /* restore context */ + current->kcsan_ctx = ctx_save; +} + +/* + * Simple test to create conflicting accesses. Write 'test=<iters>' to KCSAN's + * debugfs file from multiple tasks to generate real conflicts and show reports. + */ +static long test_dummy; +static long test_flags; +static long test_scoped; +static noinline void test_thread(unsigned long iters) +{ + const long CHANGE_BITS = 0xff00ff00ff00ff00L; + const struct kcsan_ctx ctx_save = current->kcsan_ctx; + cycles_t cycles; + + /* We may have been called from an atomic region; reset context. */ + memset(¤t->kcsan_ctx, 0, sizeof(current->kcsan_ctx)); + + pr_info("KCSAN: %s begin | iters: %lu\n", __func__, iters); + pr_info("test_dummy@%px, test_flags@%px, test_scoped@%px,\n", + &test_dummy, &test_flags, &test_scoped); + + cycles = get_cycles(); + while (iters--) { + /* These all should generate reports. */ + __kcsan_check_read(&test_dummy, sizeof(test_dummy)); + ASSERT_EXCLUSIVE_WRITER(test_dummy); + ASSERT_EXCLUSIVE_ACCESS(test_dummy); + + ASSERT_EXCLUSIVE_BITS(test_flags, ~CHANGE_BITS); /* no report */ + __kcsan_check_read(&test_flags, sizeof(test_flags)); /* no report */ + + ASSERT_EXCLUSIVE_BITS(test_flags, CHANGE_BITS); /* report */ + __kcsan_check_read(&test_flags, sizeof(test_flags)); /* no report */ + + /* not actually instrumented */ + WRITE_ONCE(test_dummy, iters); /* to observe value-change */ + __kcsan_check_write(&test_dummy, sizeof(test_dummy)); + + test_flags ^= CHANGE_BITS; /* generate value-change */ + __kcsan_check_write(&test_flags, sizeof(test_flags)); + + BUG_ON(current->kcsan_ctx.scoped_accesses.prev); + { + /* Should generate reports anywhere in this block. */ + ASSERT_EXCLUSIVE_WRITER_SCOPED(test_scoped); + ASSERT_EXCLUSIVE_ACCESS_SCOPED(test_scoped); + BUG_ON(!current->kcsan_ctx.scoped_accesses.prev); + /* Unrelated accesses. */ + __kcsan_check_access(&cycles, sizeof(cycles), 0); + __kcsan_check_access(&cycles, sizeof(cycles), KCSAN_ACCESS_ATOMIC); + } + BUG_ON(current->kcsan_ctx.scoped_accesses.prev); + } + cycles = get_cycles() - cycles; + + pr_info("KCSAN: %s end | cycles: %llu\n", __func__, cycles); + + /* restore context */ + current->kcsan_ctx = ctx_save; +} + +static int cmp_filterlist_addrs(const void *rhs, const void *lhs) +{ + const unsigned long a = *(const unsigned long *)rhs; + const unsigned long b = *(const unsigned long *)lhs; + + return a < b ? -1 : a == b ? 0 : 1; +} + +bool kcsan_skip_report_debugfs(unsigned long func_addr) +{ + unsigned long symbolsize, offset; + unsigned long flags; + bool ret = false; + + if (!kallsyms_lookup_size_offset(func_addr, &symbolsize, &offset)) + return false; + func_addr -= offset; /* Get function start */ + + spin_lock_irqsave(&report_filterlist_lock, flags); + if (report_filterlist.used == 0) + goto out; + + /* Sort array if it is unsorted, and then do a binary search. */ + if (!report_filterlist.sorted) { + sort(report_filterlist.addrs, report_filterlist.used, + sizeof(unsigned long), cmp_filterlist_addrs, NULL); + report_filterlist.sorted = true; + } + ret = !!bsearch(&func_addr, report_filterlist.addrs, + report_filterlist.used, sizeof(unsigned long), + cmp_filterlist_addrs); + if (report_filterlist.whitelist) + ret = !ret; + +out: + spin_unlock_irqrestore(&report_filterlist_lock, flags); + return ret; +} + +static void set_report_filterlist_whitelist(bool whitelist) +{ + unsigned long flags; + + spin_lock_irqsave(&report_filterlist_lock, flags); + report_filterlist.whitelist = whitelist; + spin_unlock_irqrestore(&report_filterlist_lock, flags); +} + +/* Returns 0 on success, error-code otherwise. */ +static ssize_t insert_report_filterlist(const char *func) +{ + unsigned long flags; + unsigned long addr = kallsyms_lookup_name(func); + ssize_t ret = 0; + + if (!addr) { + pr_err("KCSAN: could not find function: '%s'\n", func); + return -ENOENT; + } + + spin_lock_irqsave(&report_filterlist_lock, flags); + + if (report_filterlist.addrs == NULL) { + /* initial allocation */ + report_filterlist.addrs = + kmalloc_array(report_filterlist.size, + sizeof(unsigned long), GFP_ATOMIC); + if (report_filterlist.addrs == NULL) { + ret = -ENOMEM; + goto out; + } + } else if (report_filterlist.used == report_filterlist.size) { + /* resize filterlist */ + size_t new_size = report_filterlist.size * 2; + unsigned long *new_addrs = + krealloc(report_filterlist.addrs, + new_size * sizeof(unsigned long), GFP_ATOMIC); + + if (new_addrs == NULL) { + /* leave filterlist itself untouched */ + ret = -ENOMEM; + goto out; + } + + report_filterlist.size = new_size; + report_filterlist.addrs = new_addrs; + } + + /* Note: deduplicating should be done in userspace. */ + report_filterlist.addrs[report_filterlist.used++] = + kallsyms_lookup_name(func); + report_filterlist.sorted = false; + +out: + spin_unlock_irqrestore(&report_filterlist_lock, flags); + + return ret; +} + +static int show_info(struct seq_file *file, void *v) +{ + int i; + unsigned long flags; + + /* show stats */ + seq_printf(file, "enabled: %i\n", READ_ONCE(kcsan_enabled)); + for (i = 0; i < KCSAN_COUNTER_COUNT; ++i) + seq_printf(file, "%s: %ld\n", counter_to_name(i), + atomic_long_read(&counters[i])); + + /* show filter functions, and filter type */ + spin_lock_irqsave(&report_filterlist_lock, flags); + seq_printf(file, "\n%s functions: %s\n", + report_filterlist.whitelist ? "whitelisted" : "blacklisted", + report_filterlist.used == 0 ? "none" : ""); + for (i = 0; i < report_filterlist.used; ++i) + seq_printf(file, " %ps\n", (void *)report_filterlist.addrs[i]); + spin_unlock_irqrestore(&report_filterlist_lock, flags); + + return 0; +} + +static int debugfs_open(struct inode *inode, struct file *file) +{ + return single_open(file, show_info, NULL); +} + +static ssize_t +debugfs_write(struct file *file, const char __user *buf, size_t count, loff_t *off) +{ + char kbuf[KSYM_NAME_LEN]; + char *arg; + int read_len = count < (sizeof(kbuf) - 1) ? count : (sizeof(kbuf) - 1); + + if (copy_from_user(kbuf, buf, read_len)) + return -EFAULT; + kbuf[read_len] = '\0'; + arg = strstrip(kbuf); + + if (!strcmp(arg, "on")) { + WRITE_ONCE(kcsan_enabled, true); + } else if (!strcmp(arg, "off")) { + WRITE_ONCE(kcsan_enabled, false); + } else if (!strncmp(arg, "microbench=", sizeof("microbench=") - 1)) { + unsigned long iters; + + if (kstrtoul(&arg[sizeof("microbench=") - 1], 0, &iters)) + return -EINVAL; + microbenchmark(iters); + } else if (!strncmp(arg, "test=", sizeof("test=") - 1)) { + unsigned long iters; + + if (kstrtoul(&arg[sizeof("test=") - 1], 0, &iters)) + return -EINVAL; + test_thread(iters); + } else if (!strcmp(arg, "whitelist")) { + set_report_filterlist_whitelist(true); + } else if (!strcmp(arg, "blacklist")) { + set_report_filterlist_whitelist(false); + } else if (arg[0] == '!') { + ssize_t ret = insert_report_filterlist(&arg[1]); + + if (ret < 0) + return ret; + } else { + return -EINVAL; + } + + return count; +} + +static const struct file_operations debugfs_ops = +{ + .read = seq_read, + .open = debugfs_open, + .write = debugfs_write, + .release = single_release +}; + +void __init kcsan_debugfs_init(void) +{ + debugfs_create_file("kcsan", 0644, NULL, NULL, &debugfs_ops); +} diff --git a/kernel/kcsan/encoding.h b/kernel/kcsan/encoding.h new file mode 100644 index 000000000000..f03562aaf2eb --- /dev/null +++ b/kernel/kcsan/encoding.h @@ -0,0 +1,95 @@ +/* SPDX-License-Identifier: GPL-2.0 */ + +#ifndef _KERNEL_KCSAN_ENCODING_H +#define _KERNEL_KCSAN_ENCODING_H + +#include <linux/bits.h> +#include <linux/log2.h> +#include <linux/mm.h> + +#include "kcsan.h" + +#define SLOT_RANGE PAGE_SIZE + +#define INVALID_WATCHPOINT 0 +#define CONSUMED_WATCHPOINT 1 + +/* + * The maximum useful size of accesses for which we set up watchpoints is the + * max range of slots we check on an access. + */ +#define MAX_ENCODABLE_SIZE (SLOT_RANGE * (1 + KCSAN_CHECK_ADJACENT)) + +/* + * Number of bits we use to store size info. + */ +#define WATCHPOINT_SIZE_BITS bits_per(MAX_ENCODABLE_SIZE) +/* + * This encoding for addresses discards the upper (1 for is-write + SIZE_BITS); + * however, most 64-bit architectures do not use the full 64-bit address space. + * Also, in order for a false positive to be observable 2 things need to happen: + * + * 1. different addresses but with the same encoded address race; + * 2. and both map onto the same watchpoint slots; + * + * Both these are assumed to be very unlikely. However, in case it still happens + * happens, the report logic will filter out the false positive (see report.c). + */ +#define WATCHPOINT_ADDR_BITS (BITS_PER_LONG-1 - WATCHPOINT_SIZE_BITS) + +/* + * Masks to set/retrieve the encoded data. + */ +#define WATCHPOINT_WRITE_MASK BIT(BITS_PER_LONG-1) +#define WATCHPOINT_SIZE_MASK \ + GENMASK(BITS_PER_LONG-2, BITS_PER_LONG-2 - WATCHPOINT_SIZE_BITS) +#define WATCHPOINT_ADDR_MASK \ + GENMASK(BITS_PER_LONG-3 - WATCHPOINT_SIZE_BITS, 0) + +static inline bool check_encodable(unsigned long addr, size_t size) +{ + return size <= MAX_ENCODABLE_SIZE; +} + +static inline long +encode_watchpoint(unsigned long addr, size_t size, bool is_write) +{ + return (long)((is_write ? WATCHPOINT_WRITE_MASK : 0) | + (size << WATCHPOINT_ADDR_BITS) | + (addr & WATCHPOINT_ADDR_MASK)); +} + +static __always_inline bool decode_watchpoint(long watchpoint, + unsigned long *addr_masked, + size_t *size, + bool *is_write) +{ + if (watchpoint == INVALID_WATCHPOINT || + watchpoint == CONSUMED_WATCHPOINT) + return false; + + *addr_masked = (unsigned long)watchpoint & WATCHPOINT_ADDR_MASK; + *size = ((unsigned long)watchpoint & WATCHPOINT_SIZE_MASK) >> WATCHPOINT_ADDR_BITS; + *is_write = !!((unsigned long)watchpoint & WATCHPOINT_WRITE_MASK); + + return true; +} + +/* + * Return watchpoint slot for an address. + */ +static __always_inline int watchpoint_slot(unsigned long addr) +{ + return (addr / PAGE_SIZE) % CONFIG_KCSAN_NUM_WATCHPOINTS; +} + +static __always_inline bool matching_access(unsigned long addr1, size_t size1, + unsigned long addr2, size_t size2) +{ + unsigned long end_range1 = addr1 + size1 - 1; + unsigned long end_range2 = addr2 + size2 - 1; + + return addr1 <= end_range2 && addr2 <= end_range1; +} + +#endif /* _KERNEL_KCSAN_ENCODING_H */ diff --git a/kernel/kcsan/kcsan.h b/kernel/kcsan/kcsan.h new file mode 100644 index 000000000000..763d6d08d94b --- /dev/null +++ b/kernel/kcsan/kcsan.h @@ -0,0 +1,142 @@ +/* SPDX-License-Identifier: GPL-2.0 */ + +/* + * The Kernel Concurrency Sanitizer (KCSAN) infrastructure. For more info please + * see Documentation/dev-tools/kcsan.rst. + */ + +#ifndef _KERNEL_KCSAN_KCSAN_H +#define _KERNEL_KCSAN_KCSAN_H + +#include <linux/kcsan.h> + +/* The number of adjacent watchpoints to check. */ +#define KCSAN_CHECK_ADJACENT 1 +#define NUM_SLOTS (1 + 2*KCSAN_CHECK_ADJACENT) + +extern unsigned int kcsan_udelay_task; +extern unsigned int kcsan_udelay_interrupt; + +/* + * Globally enable and disable KCSAN. + */ +extern bool kcsan_enabled; + +/* + * Initialize debugfs file. + */ +void kcsan_debugfs_init(void); + +enum kcsan_counter_id { + /* + * Number of watchpoints currently in use. + */ + KCSAN_COUNTER_USED_WATCHPOINTS, + + /* + * Total number of watchpoints set up. + */ + KCSAN_COUNTER_SETUP_WATCHPOINTS, + + /* + * Total number of data races. + */ + KCSAN_COUNTER_DATA_RACES, + + /* + * Total number of ASSERT failures due to races. If the observed race is + * due to two conflicting ASSERT type accesses, then both will be + * counted. + */ + KCSAN_COUNTER_ASSERT_FAILURES, + + /* + * Number of times no watchpoints were available. + */ + KCSAN_COUNTER_NO_CAPACITY, + + /* + * A thread checking a watchpoint raced with another checking thread; + * only one will be reported. + */ + KCSAN_COUNTER_REPORT_RACES, + + /* + * Observed data value change, but writer thread unknown. + */ + KCSAN_COUNTER_RACES_UNKNOWN_ORIGIN, + + /* + * The access cannot be encoded to a valid watchpoint. + */ + KCSAN_COUNTER_UNENCODABLE_ACCESSES, + + /* + * Watchpoint encoding caused a watchpoint to fire on mismatching + * accesses. + */ + KCSAN_COUNTER_ENCODING_FALSE_POSITIVES, + + KCSAN_COUNTER_COUNT, /* number of counters */ +}; + +/* + * Increment/decrement counter with given id; avoid calling these in fast-path. + */ +extern void kcsan_counter_inc(enum kcsan_counter_id id); +extern void kcsan_counter_dec(enum kcsan_counter_id id); + +/* + * Returns true if data races in the function symbol that maps to func_addr + * (offsets are ignored) should *not* be reported. + */ +extern bool kcsan_skip_report_debugfs(unsigned long func_addr); + +/* + * Value-change states. + */ +enum kcsan_value_change { + /* + * Did not observe a value-change, however, it is valid to report the + * race, depending on preferences. + */ + KCSAN_VALUE_CHANGE_MAYBE, + + /* + * Did not observe a value-change, and it is invalid to report the race. + */ + KCSAN_VALUE_CHANGE_FALSE, + + /* + * The value was observed to change, and the race should be reported. + */ + KCSAN_VALUE_CHANGE_TRUE, +}; + +enum kcsan_report_type { + /* + * The thread that set up the watchpoint and briefly stalled was + * signalled that another thread triggered the watchpoint. + */ + KCSAN_REPORT_RACE_SIGNAL, + + /* + * A thread found and consumed a matching watchpoint. + */ + KCSAN_REPORT_CONSUMED_WATCHPOINT, + + /* + * No other thread was observed to race with the access, but the data + * value before and after the stall differs. + */ + KCSAN_REPORT_RACE_UNKNOWN_ORIGIN, +}; + +/* + * Print a race report from thread that encountered the race. + */ +extern void kcsan_report(const volatile void *ptr, size_t size, int access_type, + enum kcsan_value_change value_change, + enum kcsan_report_type type, int watchpoint_idx); + +#endif /* _KERNEL_KCSAN_KCSAN_H */ diff --git a/kernel/kcsan/report.c b/kernel/kcsan/report.c new file mode 100644 index 000000000000..ac5f8345bae9 --- /dev/null +++ b/kernel/kcsan/report.c @@ -0,0 +1,634 @@ +// SPDX-License-Identifier: GPL-2.0 + +#include <linux/debug_locks.h> +#include <linux/delay.h> +#include <linux/jiffies.h> +#include <linux/kernel.h> +#include <linux/lockdep.h> +#include <linux/preempt.h> +#include <linux/printk.h> +#include <linux/sched.h> +#include <linux/spinlock.h> +#include <linux/stacktrace.h> + +#include "kcsan.h" +#include "encoding.h" + +/* + * Max. number of stack entries to show in the report. + */ +#define NUM_STACK_ENTRIES 64 + +/* Common access info. */ +struct access_info { + const volatile void *ptr; + size_t size; + int access_type; + int task_pid; + int cpu_id; +}; + +/* + * Other thread info: communicated from other racing thread to thread that set + * up the watchpoint, which then prints the complete report atomically. + */ +struct other_info { + struct access_info ai; + unsigned long stack_entries[NUM_STACK_ENTRIES]; + int num_stack_entries; + + /* + * Optionally pass @current. Typically we do not need to pass @current + * via @other_info since just @task_pid is sufficient. Passing @current + * has additional overhead. + * + * To safely pass @current, we must either use get_task_struct/ + * put_task_struct, or stall the thread that populated @other_info. + * + * We cannot rely on get_task_struct/put_task_struct in case + * release_report() races with a task being released, and would have to + * free it in release_report(). This may result in deadlock if we want + * to use KCSAN on the allocators. + * + * Since we also want to reliably print held locks for + * CONFIG_KCSAN_VERBOSE, the current implementation stalls the thread + * that populated @other_info until it has been consumed. + */ + struct task_struct *task; +}; + +/* + * To never block any producers of struct other_info, we need as many elements + * as we have watchpoints (upper bound on concurrent races to report). + */ +static struct other_info other_infos[CONFIG_KCSAN_NUM_WATCHPOINTS + NUM_SLOTS-1]; + +/* + * Information about reported races; used to rate limit reporting. + */ +struct report_time { + /* + * The last time the race was reported. + */ + unsigned long time; + + /* + * The frames of the 2 threads; if only 1 thread is known, one frame + * will be 0. + */ + unsigned long frame1; + unsigned long frame2; +}; + +/* + * Since we also want to be able to debug allocators with KCSAN, to avoid + * deadlock, report_times cannot be dynamically resized with krealloc in + * rate_limit_report. + * + * Therefore, we use a fixed-size array, which at most will occupy a page. This + * still adequately rate limits reports, assuming that a) number of unique data + * races is not excessive, and b) occurrence of unique races within the + * same time window is limited. + */ +#define REPORT_TIMES_MAX (PAGE_SIZE / sizeof(struct report_time)) +#define REPORT_TIMES_SIZE \ + (CONFIG_KCSAN_REPORT_ONCE_IN_MS > REPORT_TIMES_MAX ? \ + REPORT_TIMES_MAX : \ + CONFIG_KCSAN_REPORT_ONCE_IN_MS) +static struct report_time report_times[REPORT_TIMES_SIZE]; + +/* + * Spinlock serializing report generation, and access to @other_infos. Although + * it could make sense to have a finer-grained locking story for @other_infos, + * report generation needs to be serialized either way, so not much is gained. + */ +static DEFINE_RAW_SPINLOCK(report_lock); + +/* + * Checks if the race identified by thread frames frame1 and frame2 has + * been reported since (now - KCSAN_REPORT_ONCE_IN_MS). + */ +static bool rate_limit_report(unsigned long frame1, unsigned long frame2) +{ + struct report_time *use_entry = &report_times[0]; + unsigned long invalid_before; + int i; + + BUILD_BUG_ON(CONFIG_KCSAN_REPORT_ONCE_IN_MS != 0 && REPORT_TIMES_SIZE == 0); + + if (CONFIG_KCSAN_REPORT_ONCE_IN_MS == 0) + return false; + + invalid_before = jiffies - msecs_to_jiffies(CONFIG_KCSAN_REPORT_ONCE_IN_MS); + + /* Check if a matching race report exists. */ + for (i = 0; i < REPORT_TIMES_SIZE; ++i) { + struct report_time *rt = &report_times[i]; + + /* + * Must always select an entry for use to store info as we + * cannot resize report_times; at the end of the scan, use_entry + * will be the oldest entry, which ideally also happened before + * KCSAN_REPORT_ONCE_IN_MS ago. + */ + if (time_before(rt->time, use_entry->time)) + use_entry = rt; + + /* + * Initially, no need to check any further as this entry as well + * as following entries have never been used. + */ + if (rt->time == 0) + break; + + /* Check if entry expired. */ + if (time_before(rt->time, invalid_before)) + continue; /* before KCSAN_REPORT_ONCE_IN_MS ago */ + + /* Reported recently, check if race matches. */ + if ((rt->frame1 == frame1 && rt->frame2 == frame2) || + (rt->frame1 == frame2 && rt->frame2 == frame1)) + return true; + } + + use_entry->time = jiffies; + use_entry->frame1 = frame1; + use_entry->frame2 = frame2; + return false; +} + +/* + * Special rules to skip reporting. + */ +static bool +skip_report(enum kcsan_value_change value_change, unsigned long top_frame) +{ + /* Should never get here if value_change==FALSE. */ + WARN_ON_ONCE(value_change == KCSAN_VALUE_CHANGE_FALSE); + + /* + * The first call to skip_report always has value_change==TRUE, since we + * cannot know the value written of an instrumented access. For the 2nd + * call there are 6 cases with CONFIG_KCSAN_REPORT_VALUE_CHANGE_ONLY: + * + * 1. read watchpoint, conflicting write (value_change==TRUE): report; + * 2. read watchpoint, conflicting write (value_change==MAYBE): skip; + * 3. write watchpoint, conflicting write (value_change==TRUE): report; + * 4. write watchpoint, conflicting write (value_change==MAYBE): skip; + * 5. write watchpoint, conflicting read (value_change==MAYBE): skip; + * 6. write watchpoint, conflicting read (value_change==TRUE): report; + * + * Cases 1-4 are intuitive and expected; case 5 ensures we do not report + * data races where the write may have rewritten the same value; case 6 + * is possible either if the size is larger than what we check value + * changes for or the access type is KCSAN_ACCESS_ASSERT. + */ + if (IS_ENABLED(CONFIG_KCSAN_REPORT_VALUE_CHANGE_ONLY) && + value_change == KCSAN_VALUE_CHANGE_MAYBE) { + /* + * The access is a write, but the data value did not change. + * + * We opt-out of this filter for certain functions at request of + * maintainers. + */ + char buf[64]; + int len = scnprintf(buf, sizeof(buf), "%ps", (void *)top_frame); + + if (!strnstr(buf, "rcu_", len) && + !strnstr(buf, "_rcu", len) && + !strnstr(buf, "_srcu", len)) + return true; + } + + return kcsan_skip_report_debugfs(top_frame); +} + +static const char *get_access_type(int type) +{ + if (type & KCSAN_ACCESS_ASSERT) { + if (type & KCSAN_ACCESS_SCOPED) { + if (type & KCSAN_ACCESS_WRITE) + return "assert no accesses (scoped)"; + else + return "assert no writes (scoped)"; + } else { + if (type & KCSAN_ACCESS_WRITE) + return "assert no accesses"; + else + return "assert no writes"; + } + } + + switch (type) { + case 0: + return "read"; + case KCSAN_ACCESS_ATOMIC: + return "read (marked)"; + case KCSAN_ACCESS_WRITE: + return "write"; + case KCSAN_ACCESS_WRITE | KCSAN_ACCESS_ATOMIC: + return "write (marked)"; + case KCSAN_ACCESS_SCOPED: + return "read (scoped)"; + case KCSAN_ACCESS_SCOPED | KCSAN_ACCESS_ATOMIC: + return "read (marked, scoped)"; + case KCSAN_ACCESS_SCOPED | KCSAN_ACCESS_WRITE: + return "write (scoped)"; + case KCSAN_ACCESS_SCOPED | KCSAN_ACCESS_WRITE | KCSAN_ACCESS_ATOMIC: + return "write (marked, scoped)"; + default: + BUG(); + } +} + +static const char *get_bug_type(int type) +{ + return (type & KCSAN_ACCESS_ASSERT) != 0 ? "assert: race" : "data-race"; +} + +/* Return thread description: in task or interrupt. */ +static const char *get_thread_desc(int task_id) +{ + if (task_id != -1) { + static char buf[32]; /* safe: protected by report_lock */ + + snprintf(buf, sizeof(buf), "task %i", task_id); + return buf; + } + return "interrupt"; +} + +/* Helper to skip KCSAN-related functions in stack-trace. */ +static int get_stack_skipnr(const unsigned long stack_entries[], int num_entries) +{ + char buf[64]; + char *cur; + int len, skip; + + for (skip = 0; skip < num_entries; ++skip) { + len = scnprintf(buf, sizeof(buf), "%ps", (void *)stack_entries[skip]); + + /* Never show tsan_* or {read,write}_once_size. */ + if (strnstr(buf, "tsan_", len) || + strnstr(buf, "_once_size", len)) + continue; + + cur = strnstr(buf, "kcsan_", len); + if (cur) { + cur += sizeof("kcsan_") - 1; + if (strncmp(cur, "test", sizeof("test") - 1)) + continue; /* KCSAN runtime function. */ + /* KCSAN related test. */ + } + + /* + * No match for runtime functions -- @skip entries to skip to + * get to first frame of interest. + */ + break; + } + + return skip; +} + +/* Compares symbolized strings of addr1 and addr2. */ +static int sym_strcmp(void *addr1, void *addr2) +{ + char buf1[64]; + char buf2[64]; + + snprintf(buf1, sizeof(buf1), "%pS", addr1); + snprintf(buf2, sizeof(buf2), "%pS", addr2); + + return strncmp(buf1, buf2, sizeof(buf1)); +} + +static void print_verbose_info(struct task_struct *task) +{ + if (!task) + return; + + pr_err("\n"); + debug_show_held_locks(task); + print_irqtrace_events(task); +} + +/* + * Returns true if a report was generated, false otherwise. + */ +static bool print_report(enum kcsan_value_change value_change, + enum kcsan_report_type type, + const struct access_info *ai, + const struct other_info *other_info) +{ + unsigned long stack_entries[NUM_STACK_ENTRIES] = { 0 }; + int num_stack_entries = stack_trace_save(stack_entries, NUM_STACK_ENTRIES, 1); + int skipnr = get_stack_skipnr(stack_entries, num_stack_entries); + unsigned long this_frame = stack_entries[skipnr]; + unsigned long other_frame = 0; + int other_skipnr = 0; /* silence uninit warnings */ + + /* + * Must check report filter rules before starting to print. + */ + if (skip_report(KCSAN_VALUE_CHANGE_TRUE, stack_entries[skipnr])) + return false; + + if (type == KCSAN_REPORT_RACE_SIGNAL) { + other_skipnr = get_stack_skipnr(other_info->stack_entries, + other_info->num_stack_entries); + other_frame = other_info->stack_entries[other_skipnr]; + + /* @value_change is only known for the other thread */ + if (skip_report(value_change, other_frame)) + return false; + } + + if (rate_limit_report(this_frame, other_frame)) + return false; + + /* Print report header. */ + pr_err("==================================================================\n"); + switch (type) { + case KCSAN_REPORT_RACE_SIGNAL: { + int cmp; + + /* + * Order functions lexographically for consistent bug titles. + * Do not print offset of functions to keep title short. + */ + cmp = sym_strcmp((void *)other_frame, (void *)this_frame); + pr_err("BUG: KCSAN: %s in %ps / %ps\n", + get_bug_type(ai->access_type | other_info->ai.access_type), + (void *)(cmp < 0 ? other_frame : this_frame), + (void *)(cmp < 0 ? this_frame : other_frame)); + } break; + + case KCSAN_REPORT_RACE_UNKNOWN_ORIGIN: + pr_err("BUG: KCSAN: %s in %pS\n", get_bug_type(ai->access_type), + (void *)this_frame); + break; + + default: + BUG(); + } + + pr_err("\n"); + + /* Print information about the racing accesses. */ + switch (type) { + case KCSAN_REPORT_RACE_SIGNAL: + pr_err("%s to 0x%px of %zu bytes by %s on cpu %i:\n", + get_access_type(other_info->ai.access_type), other_info->ai.ptr, + other_info->ai.size, get_thread_desc(other_info->ai.task_pid), + other_info->ai.cpu_id); + + /* Print the other thread's stack trace. */ + stack_trace_print(other_info->stack_entries + other_skipnr, + other_info->num_stack_entries - other_skipnr, + 0); + + if (IS_ENABLED(CONFIG_KCSAN_VERBOSE)) + print_verbose_info(other_info->task); + + pr_err("\n"); + pr_err("%s to 0x%px of %zu bytes by %s on cpu %i:\n", + get_access_type(ai->access_type), ai->ptr, ai->size, + get_thread_desc(ai->task_pid), ai->cpu_id); + break; + + case KCSAN_REPORT_RACE_UNKNOWN_ORIGIN: + pr_err("race at unknown origin, with %s to 0x%px of %zu bytes by %s on cpu %i:\n", + get_access_type(ai->access_type), ai->ptr, ai->size, + get_thread_desc(ai->task_pid), ai->cpu_id); + break; + + default: + BUG(); + } + /* Print stack trace of this thread. */ + stack_trace_print(stack_entries + skipnr, num_stack_entries - skipnr, + 0); + + if (IS_ENABLED(CONFIG_KCSAN_VERBOSE)) + print_verbose_info(current); + + /* Print report footer. */ + pr_err("\n"); + pr_err("Reported by Kernel Concurrency Sanitizer on:\n"); + dump_stack_print_info(KERN_DEFAULT); + pr_err("==================================================================\n"); + + return true; +} + +static void release_report(unsigned long *flags, struct other_info *other_info) +{ + if (other_info) + /* + * Use size to denote valid/invalid, since KCSAN entirely + * ignores 0-sized accesses. + */ + other_info->ai.size = 0; + + raw_spin_unlock_irqrestore(&report_lock, *flags); +} + +/* + * Sets @other_info->task and awaits consumption of @other_info. + * + * Precondition: report_lock is held. + * Postcondition: report_lock is held. + */ +static void set_other_info_task_blocking(unsigned long *flags, + const struct access_info *ai, + struct other_info *other_info) +{ + /* + * We may be instrumenting a code-path where current->state is already + * something other than TASK_RUNNING. + */ + const bool is_running = current->state == TASK_RUNNING; + /* + * To avoid deadlock in case we are in an interrupt here and this is a + * race with a task on the same CPU (KCSAN_INTERRUPT_WATCHER), provide a + * timeout to ensure this works in all contexts. + * + * Await approximately the worst case delay of the reporting thread (if + * we are not interrupted). + */ + int timeout = max(kcsan_udelay_task, kcsan_udelay_interrupt); + + other_info->task = current; + do { + if (is_running) { + /* + * Let lockdep know the real task is sleeping, to print + * the held locks (recall we turned lockdep off, so + * locking/unlocking @report_lock won't be recorded). + */ + set_current_state(TASK_UNINTERRUPTIBLE); + } + raw_spin_unlock_irqrestore(&report_lock, *flags); + /* + * We cannot call schedule() since we also cannot reliably + * determine if sleeping here is permitted -- see in_atomic(). + */ + + udelay(1); + raw_spin_lock_irqsave(&report_lock, *flags); + if (timeout-- < 0) { + /* + * Abort. Reset @other_info->task to NULL, since it + * appears the other thread is still going to consume + * it. It will result in no verbose info printed for + * this task. + */ + other_info->task = NULL; + break; + } + /* + * If invalid, or @ptr nor @current matches, then @other_info + * has been consumed and we may continue. If not, retry. + */ + } while (other_info->ai.size && other_info->ai.ptr == ai->ptr && + other_info->task == current); + if (is_running) + set_current_state(TASK_RUNNING); +} + +/* Populate @other_info; requires that the provided @other_info not in use. */ +static void prepare_report_producer(unsigned long *flags, + const struct access_info *ai, + struct other_info *other_info) +{ + raw_spin_lock_irqsave(&report_lock, *flags); + + /* + * The same @other_infos entry cannot be used concurrently, because + * there is a one-to-one mapping to watchpoint slots (@watchpoints in + * core.c), and a watchpoint is only released for reuse after reporting + * is done by the consumer of @other_info. Therefore, it is impossible + * for another concurrent prepare_report_producer() to set the same + * @other_info, and are guaranteed exclusivity for the @other_infos + * entry pointed to by @other_info. + * + * To check this property holds, size should never be non-zero here, + * because every consumer of struct other_info resets size to 0 in + * release_report(). + */ + WARN_ON(other_info->ai.size); + + other_info->ai = *ai; + other_info->num_stack_entries = stack_trace_save(other_info->stack_entries, NUM_STACK_ENTRIES, 2); + + if (IS_ENABLED(CONFIG_KCSAN_VERBOSE)) + set_other_info_task_blocking(flags, ai, other_info); + + raw_spin_unlock_irqrestore(&report_lock, *flags); +} + +/* Awaits producer to fill @other_info and then returns. */ +static bool prepare_report_consumer(unsigned long *flags, + const struct access_info *ai, + struct other_info *other_info) +{ + + raw_spin_lock_irqsave(&report_lock, *flags); + while (!other_info->ai.size) { /* Await valid @other_info. */ + raw_spin_unlock_irqrestore(&report_lock, *flags); + cpu_relax(); + raw_spin_lock_irqsave(&report_lock, *flags); + } + + /* Should always have a matching access based on watchpoint encoding. */ + if (WARN_ON(!matching_access((unsigned long)other_info->ai.ptr & WATCHPOINT_ADDR_MASK, other_info->ai.size, + (unsigned long)ai->ptr & WATCHPOINT_ADDR_MASK, ai->size))) + goto discard; + + if (!matching_access((unsigned long)other_info->ai.ptr, other_info->ai.size, + (unsigned long)ai->ptr, ai->size)) { + /* + * If the actual accesses to not match, this was a false + * positive due to watchpoint encoding. + */ + kcsan_counter_inc(KCSAN_COUNTER_ENCODING_FALSE_POSITIVES); + goto discard; + } + + return true; + +discard: + release_report(flags, other_info); + return false; +} + +/* + * Depending on the report type either sets @other_info and returns false, or + * awaits @other_info and returns true. If @other_info is not required for the + * report type, simply acquires @report_lock and returns true. + */ +static noinline bool prepare_report(unsigned long *flags, + enum kcsan_report_type type, + const struct access_info *ai, + struct other_info *other_info) +{ + switch (type) { + case KCSAN_REPORT_CONSUMED_WATCHPOINT: + prepare_report_producer(flags, ai, other_info); + return false; + case KCSAN_REPORT_RACE_SIGNAL: + return prepare_report_consumer(flags, ai, other_info); + default: + /* @other_info not required; just acquire @report_lock. */ + raw_spin_lock_irqsave(&report_lock, *flags); + return true; + } +} + +void kcsan_report(const volatile void *ptr, size_t size, int access_type, + enum kcsan_value_change value_change, + enum kcsan_report_type type, int watchpoint_idx) +{ + unsigned long flags = 0; + const struct access_info ai = { + .ptr = ptr, + .size = size, + .access_type = access_type, + .task_pid = in_task() ? task_pid_nr(current) : -1, + .cpu_id = raw_smp_processor_id() + }; + struct other_info *other_info = type == KCSAN_REPORT_RACE_UNKNOWN_ORIGIN + ? NULL : &other_infos[watchpoint_idx]; + + kcsan_disable_current(); + if (WARN_ON(watchpoint_idx < 0 || watchpoint_idx >= ARRAY_SIZE(other_infos))) + goto out; + + /* + * With TRACE_IRQFLAGS, lockdep's IRQ trace state becomes corrupted if + * we do not turn off lockdep here; this could happen due to recursion + * into lockdep via KCSAN if we detect a race in utilities used by + * lockdep. + */ + lockdep_off(); + + if (prepare_report(&flags, type, &ai, other_info)) { + /* + * Never report if value_change is FALSE, only if we it is + * either TRUE or MAYBE. In case of MAYBE, further filtering may + * be done once we know the full stack trace in print_report(). + */ + bool reported = value_change != KCSAN_VALUE_CHANGE_FALSE && + print_report(value_change, type, &ai, other_info); + + if (reported && panic_on_warn) + panic("panic_on_warn set ...\n"); + + release_report(&flags, other_info); + } + + lockdep_on(); +out: + kcsan_enable_current(); +} diff --git a/kernel/kcsan/test.c b/kernel/kcsan/test.c new file mode 100644 index 000000000000..d26a052d3383 --- /dev/null +++ b/kernel/kcsan/test.c @@ -0,0 +1,131 @@ +// SPDX-License-Identifier: GPL-2.0 + +#include <linux/init.h> +#include <linux/kernel.h> +#include <linux/printk.h> +#include <linux/random.h> +#include <linux/types.h> + +#include "encoding.h" + +#define ITERS_PER_TEST 2000 + +/* Test requirements. */ +static bool test_requires(void) +{ + /* random should be initialized for the below tests */ + return prandom_u32() + prandom_u32() != 0; +} + +/* + * Test watchpoint encode and decode: check that encoding some access's info, + * and then subsequent decode preserves the access's info. + */ +static bool test_encode_decode(void) +{ + int i; + + for (i = 0; i < ITERS_PER_TEST; ++i) { + size_t size = prandom_u32_max(MAX_ENCODABLE_SIZE) + 1; + bool is_write = !!prandom_u32_max(2); + unsigned long addr; + + prandom_bytes(&addr, sizeof(addr)); + if (WARN_ON(!check_encodable(addr, size))) + return false; + + /* Encode and decode */ + { + const long encoded_watchpoint = + encode_watchpoint(addr, size, is_write); + unsigned long verif_masked_addr; + size_t verif_size; + bool verif_is_write; + + /* Check special watchpoints */ + if (WARN_ON(decode_watchpoint( + INVALID_WATCHPOINT, &verif_masked_addr, + &verif_size, &verif_is_write))) + return false; + if (WARN_ON(decode_watchpoint( + CONSUMED_WATCHPOINT, &verif_masked_addr, + &verif_size, &verif_is_write))) + return false; + + /* Check decoding watchpoint returns same data */ + if (WARN_ON(!decode_watchpoint( + encoded_watchpoint, &verif_masked_addr, + &verif_size, &verif_is_write))) + return false; + if (WARN_ON(verif_masked_addr != + (addr & WATCHPOINT_ADDR_MASK))) + goto fail; + if (WARN_ON(verif_size != size)) + goto fail; + if (WARN_ON(is_write != verif_is_write)) + goto fail; + + continue; +fail: + pr_err("%s fail: %s %zu bytes @ %lx -> encoded: %lx -> %s %zu bytes @ %lx\n", + __func__, is_write ? "write" : "read", size, + addr, encoded_watchpoint, + verif_is_write ? "write" : "read", verif_size, + verif_masked_addr); + return false; + } + } + + return true; +} + +/* Test access matching function. */ +static bool test_matching_access(void) +{ + if (WARN_ON(!matching_access(10, 1, 10, 1))) + return false; + if (WARN_ON(!matching_access(10, 2, 11, 1))) + return false; + if (WARN_ON(!matching_access(10, 1, 9, 2))) + return false; + if (WARN_ON(matching_access(10, 1, 11, 1))) + return false; + if (WARN_ON(matching_access(9, 1, 10, 1))) + return false; + + /* + * An access of size 0 could match another access, as demonstrated here. + * Rather than add more comparisons to 'matching_access()', which would + * end up in the fast-path for *all* checks, check_access() simply + * returns for all accesses of size 0. + */ + if (WARN_ON(!matching_access(8, 8, 12, 0))) + return false; + + return true; +} + +static int __init kcsan_selftest(void) +{ + int passed = 0; + int total = 0; + +#define RUN_TEST(do_test) \ + do { \ + ++total; \ + if (do_test()) \ + ++passed; \ + else \ + pr_err("KCSAN selftest: " #do_test " failed"); \ + } while (0) + + RUN_TEST(test_requires); + RUN_TEST(test_encode_decode); + RUN_TEST(test_matching_access); + + pr_info("KCSAN selftest: %d/%d tests passed\n", passed, total); + if (passed != total) + panic("KCSAN selftests failed"); + return 0; +} +postcore_initcall(kcsan_selftest); diff --git a/kernel/locking/Makefile b/kernel/locking/Makefile index 45452facff3b..6d11cfb9b41f 100644 --- a/kernel/locking/Makefile +++ b/kernel/locking/Makefile @@ -5,6 +5,9 @@ KCOV_INSTRUMENT := n obj-y += mutex.o semaphore.o rwsem.o percpu-rwsem.o +# Avoid recursion lockdep -> KCSAN -> ... -> lockdep. +KCSAN_SANITIZE_lockdep.o := n + ifdef CONFIG_FUNCTION_TRACER CFLAGS_REMOVE_lockdep.o = $(CC_FLAGS_FTRACE) CFLAGS_REMOVE_lockdep_proc.o = $(CC_FLAGS_FTRACE) diff --git a/kernel/sched/Makefile b/kernel/sched/Makefile index 21fb5a5662b5..5fc9c9b70862 100644 --- a/kernel/sched/Makefile +++ b/kernel/sched/Makefile @@ -7,6 +7,12 @@ endif # that is not a function of syscall inputs. E.g. involuntary context switches. KCOV_INSTRUMENT := n +# There are numerous data races here, however, most of them are due to plain accesses. +# This would make it even harder for syzbot to find reproducers, because these +# bugs trigger without specific input. Disable by default, but should re-enable +# eventually. +KCSAN_SANITIZE := n + ifneq ($(CONFIG_SCHED_OMIT_FRAME_POINTER),y) # According to Alan Modra <alan@linuxcare.com.au>, the -fno-omit-frame-pointer is # needed for x86 only. Why this used to be enabled for all architectures is beyond diff --git a/kernel/trace/Makefile b/kernel/trace/Makefile index 1d8aaa546412..6575bb0a0434 100644 --- a/kernel/trace/Makefile +++ b/kernel/trace/Makefile @@ -6,6 +6,9 @@ ifdef CONFIG_FUNCTION_TRACER ORIG_CFLAGS := $(KBUILD_CFLAGS) KBUILD_CFLAGS = $(subst $(CC_FLAGS_FTRACE),,$(ORIG_CFLAGS)) +# Avoid recursion due to instrumentation. +KCSAN_SANITIZE := n + ifdef CONFIG_FTRACE_SELFTEST # selftest needs instrumentation CFLAGS_trace_selftest_dynamic.o = $(CC_FLAGS_FTRACE) diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index cb98741601bd..90e16bfe27c7 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -1570,6 +1570,8 @@ config PROVIDE_OHCI1394_DMA_INIT source "samples/Kconfig" +source "lib/Kconfig.kcsan" + config ARCH_HAS_DEVMEM_IS_ALLOWED bool diff --git a/lib/Kconfig.kcsan b/lib/Kconfig.kcsan new file mode 100644 index 000000000000..689b6b81f272 --- /dev/null +++ b/lib/Kconfig.kcsan @@ -0,0 +1,181 @@ +# SPDX-License-Identifier: GPL-2.0-only + +config HAVE_ARCH_KCSAN + bool + +menuconfig KCSAN + bool "KCSAN: dynamic data race detector" + depends on HAVE_ARCH_KCSAN && DEBUG_KERNEL && !KASAN + select STACKTRACE + help + The Kernel Concurrency Sanitizer (KCSAN) is a dynamic + data-race detector that relies on compile-time instrumentation. + KCSAN uses a watchpoint-based sampling approach to detect races. + + While KCSAN's primary purpose is to detect data races, it + also provides assertions to check data access constraints. + These assertions can expose bugs that do not manifest as + data races. + + See <file:Documentation/dev-tools/kcsan.rst> for more details. + +if KCSAN + +config KCSAN_VERBOSE + bool "Show verbose reports with more information about system state" + depends on PROVE_LOCKING + help + If enabled, reports show more information about the system state that + may help better analyze and debug races. This includes held locks and + IRQ trace events. + + While this option should generally be benign, we call into more + external functions on report generation; if a race report is + generated from any one of them, system stability may suffer due to + deadlocks or recursion. If in doubt, say N. + +config KCSAN_DEBUG + bool "Debugging of KCSAN internals" + +config KCSAN_SELFTEST + bool "Perform short selftests on boot" + default y + help + Run KCSAN selftests on boot. On test failure, causes the kernel to panic. + +config KCSAN_EARLY_ENABLE + bool "Early enable during boot" + default y + help + If KCSAN should be enabled globally as soon as possible. KCSAN can + later be enabled/disabled via debugfs. + +config KCSAN_NUM_WATCHPOINTS + int "Number of available watchpoints" + default 64 + help + Total number of available watchpoints. An address range maps into a + specific watchpoint slot as specified in kernel/kcsan/encoding.h. + Although larger number of watchpoints may not be usable due to + limited number of CPUs, a larger value helps to improve performance + due to reducing cache-line contention. The chosen default is a + conservative value; we should almost never observe "no_capacity" + events (see /sys/kernel/debug/kcsan). + +config KCSAN_UDELAY_TASK + int "Delay in microseconds (for tasks)" + default 80 + help + For tasks, the microsecond delay after setting up a watchpoint. + +config KCSAN_UDELAY_INTERRUPT + int "Delay in microseconds (for interrupts)" + default 20 + help + For interrupts, the microsecond delay after setting up a watchpoint. + Interrupts have tighter latency requirements, and their delay should + be lower than for tasks. + +config KCSAN_DELAY_RANDOMIZE + bool "Randomize above delays" + default y + help + If delays should be randomized, where the maximum is KCSAN_UDELAY_*. + If false, the chosen delays are always the KCSAN_UDELAY_* values + as defined above. + +config KCSAN_SKIP_WATCH + int "Skip instructions before setting up watchpoint" + default 4000 + help + The number of per-CPU memory operations to skip, before another + watchpoint is set up, i.e. one in KCSAN_WATCH_SKIP per-CPU + memory operations are used to set up a watchpoint. A smaller value + results in more aggressive race detection, whereas a larger value + improves system performance at the cost of missing some races. + +config KCSAN_SKIP_WATCH_RANDOMIZE + bool "Randomize watchpoint instruction skip count" + default y + help + If instruction skip count should be randomized, where the maximum is + KCSAN_WATCH_SKIP. If false, the chosen value is always + KCSAN_WATCH_SKIP. + +config KCSAN_INTERRUPT_WATCHER + bool "Interruptible watchers" + help + If enabled, a task that set up a watchpoint may be interrupted while + delayed. This option will allow KCSAN to detect races between + interrupted tasks and other threads of execution on the same CPU. + + Currently disabled by default, because not all safe per-CPU access + primitives and patterns may be accounted for, and therefore could + result in false positives. + +config KCSAN_REPORT_ONCE_IN_MS + int "Duration in milliseconds, in which any given race is only reported once" + default 3000 + help + Any given race is only reported once in the defined time window. + Different races may still generate reports within a duration that is + smaller than the duration defined here. This allows rate limiting + reporting to avoid flooding the console with reports. Setting this + to 0 disables rate limiting. + +# The main purpose of the below options is to control reported data races (e.g. +# in fuzzer configs), and are not expected to be switched frequently by other +# users. We could turn some of them into boot parameters, but given they should +# not be switched normally, let's keep them here to simplify configuration. +# +# The defaults below are chosen to be very conservative, and may miss certain +# bugs. + +config KCSAN_REPORT_RACE_UNKNOWN_ORIGIN + bool "Report races of unknown origin" + default y + help + If KCSAN should report races where only one access is known, and the + conflicting access is of unknown origin. This type of race is + reported if it was only possible to infer a race due to a data value + change while an access is being delayed on a watchpoint. + +config KCSAN_REPORT_VALUE_CHANGE_ONLY + bool "Only report races where watcher observed a data value change" + default y + help + If enabled and a conflicting write is observed via a watchpoint, but + the data value of the memory location was observed to remain + unchanged, do not report the data race. + +config KCSAN_ASSUME_PLAIN_WRITES_ATOMIC + bool "Assume that plain aligned writes up to word size are atomic" + default y + help + Assume that plain aligned writes up to word size are atomic by + default, and also not subject to other unsafe compiler optimizations + resulting in data races. This will cause KCSAN to not report data + races due to conflicts where the only plain accesses are aligned + writes up to word size: conflicts between marked reads and plain + aligned writes up to word size will not be reported as data races; + notice that data races between two conflicting plain aligned writes + will also not be reported. + +config KCSAN_IGNORE_ATOMICS + bool "Do not instrument marked atomic accesses" + help + Never instrument marked atomic accesses. This option can be used for + additional filtering. Conflicting marked atomic reads and plain + writes will never be reported as a data race, however, will cause + plain reads and marked writes to result in "unknown origin" reports. + If combined with CONFIG_KCSAN_REPORT_RACE_UNKNOWN_ORIGIN=n, data + races where at least one access is marked atomic will never be + reported. + + Similar to KCSAN_ASSUME_PLAIN_WRITES_ATOMIC, but including unaligned + accesses, conflicting marked atomic reads and plain writes will not + be reported as data races; however, unlike that option, data races + due to two conflicting plain writes will be reported (aligned and + unaligned, if CONFIG_KCSAN_ASSUME_PLAIN_WRITES_ATOMIC=n). + +endif # KCSAN diff --git a/lib/Makefile b/lib/Makefile index 315516fa4ef4..b1c42c10073b 100644 --- a/lib/Makefile +++ b/lib/Makefile @@ -25,6 +25,9 @@ KASAN_SANITIZE_string.o := n CFLAGS_string.o := $(call cc-option, -fno-stack-protector) endif +# Used by KCSAN while enabled, avoid recursion. +KCSAN_SANITIZE_random32.o := n + lib-y := ctype.o string.o vsprintf.o cmdline.o \ rbtree.o radix-tree.o timerqueue.o xarray.o \ idr.o extable.o sha1.o irq_regs.o argv_split.o \ @@ -296,6 +299,7 @@ endif UBSAN_SANITIZE_ubsan.o := n KASAN_SANITIZE_ubsan.o := n +KCSAN_SANITIZE_ubsan.o := n CFLAGS_ubsan.o := $(call cc-option, -fno-stack-protector) $(DISABLE_STACKLEAK_PLUGIN) obj-$(CONFIG_SBITMAP) += sbitmap.o diff --git a/lib/iov_iter.c b/lib/iov_iter.c index 51595bf3af85..bf538c2bec77 100644 --- a/lib/iov_iter.c +++ b/lib/iov_iter.c @@ -8,6 +8,7 @@ #include <linux/splice.h> #include <net/checksum.h> #include <linux/scatterlist.h> +#include <linux/instrumented.h> #define PIPE_PARANOIA /* for now */ @@ -138,7 +139,7 @@ static int copyout(void __user *to, const void *from, size_t n) { if (access_ok(to, n)) { - kasan_check_read(from, n); + instrument_copy_to_user(to, from, n); n = raw_copy_to_user(to, from, n); } return n; @@ -147,7 +148,7 @@ static int copyout(void __user *to, const void *from, size_t n) static int copyin(void *to, const void __user *from, size_t n) { if (access_ok(from, n)) { - kasan_check_write(to, n); + instrument_copy_from_user(to, from, n); n = raw_copy_from_user(to, from, n); } return n; @@ -639,7 +640,7 @@ EXPORT_SYMBOL(_copy_to_iter); static int copyout_mcsafe(void __user *to, const void *from, size_t n) { if (access_ok(to, n)) { - kasan_check_read(from, n); + instrument_copy_to_user(to, from, n); n = copy_to_user_mcsafe((__force void *) to, from, n); } return n; diff --git a/lib/usercopy.c b/lib/usercopy.c index ca2a697a2061..b26509f112f9 100644 --- a/lib/usercopy.c +++ b/lib/usercopy.c @@ -1,6 +1,7 @@ // SPDX-License-Identifier: GPL-2.0 -#include <linux/uaccess.h> #include <linux/bitops.h> +#include <linux/instrumented.h> +#include <linux/uaccess.h> /* out-of-line parts */ @@ -10,7 +11,7 @@ unsigned long _copy_from_user(void *to, const void __user *from, unsigned long n unsigned long res = n; might_fault(); if (likely(access_ok(from, n))) { - kasan_check_write(to, n); + instrument_copy_from_user(to, from, n); res = raw_copy_from_user(to, from, n); } if (unlikely(res)) @@ -25,7 +26,7 @@ unsigned long _copy_to_user(void __user *to, const void *from, unsigned long n) { might_fault(); if (likely(access_ok(to, n))) { - kasan_check_read(from, n); + instrument_copy_to_user(to, from, n); n = raw_copy_to_user(to, from, n); } return n; diff --git a/mm/Makefile b/mm/Makefile index 662fd1504646..fa91e963c2f9 100644 --- a/mm/Makefile +++ b/mm/Makefile @@ -8,6 +8,14 @@ KASAN_SANITIZE_slab.o := n KASAN_SANITIZE_slub.o := n KCSAN_SANITIZE_kmemleak.o := n +# These produce frequent data race reports: most of them are due to races on +# the same word but accesses to different bits of that word. Re-enable KCSAN +# for these when we have more consensus on what to do about them. +KCSAN_SANITIZE_slab_common.o := n +KCSAN_SANITIZE_slab.o := n +KCSAN_SANITIZE_slub.o := n +KCSAN_SANITIZE_page_alloc.o := n + # These files are disabled because they produce non-interesting and/or # flaky coverage that is not a function of syscall inputs. E.g. slab is out of # free pages, or a task is migrated between nodes. diff --git a/scripts/Makefile.kcsan b/scripts/Makefile.kcsan new file mode 100644 index 000000000000..caf1111a28ae --- /dev/null +++ b/scripts/Makefile.kcsan @@ -0,0 +1,6 @@ +# SPDX-License-Identifier: GPL-2.0 +ifdef CONFIG_KCSAN + +CFLAGS_KCSAN := -fsanitize=thread + +endif # CONFIG_KCSAN diff --git a/scripts/Makefile.lib b/scripts/Makefile.lib index 127f2a7e3ced..e3f047692aeb 100644 --- a/scripts/Makefile.lib +++ b/scripts/Makefile.lib @@ -152,6 +152,16 @@ _c_flags += $(if $(patsubst n%,, \ $(CFLAGS_KCOV)) endif +# +# Enable KCSAN flags except some files or directories we don't want to check +# (depends on variables KCSAN_SANITIZE_obj.o, KCSAN_SANITIZE) +# +ifeq ($(CONFIG_KCSAN),y) +_c_flags += $(if $(patsubst n%,, \ + $(KCSAN_SANITIZE_$(basetarget).o)$(KCSAN_SANITIZE)y), \ + $(CFLAGS_KCSAN)) +endif + # $(srctree)/$(src) for including checkin headers from generated source files # $(objtree)/$(obj) for including generated headers from checkin source files ifeq ($(KBUILD_EXTMOD),) diff --git a/scripts/atomic/gen-atomic-instrumented.sh b/scripts/atomic/gen-atomic-instrumented.sh index e09812372b17..6afadf73da17 100755 --- a/scripts/atomic/gen-atomic-instrumented.sh +++ b/scripts/atomic/gen-atomic-instrumented.sh @@ -20,7 +20,7 @@ gen_param_check() # We don't write to constant parameters [ ${type#c} != ${type} ] && rw="read" - printf "\tkasan_check_${rw}(${name}, sizeof(*${name}));\n" + printf "\tinstrument_atomic_${rw}(${name}, sizeof(*${name}));\n" } #gen_param_check(arg...) @@ -84,7 +84,7 @@ gen_proto_order_variant() [ ! -z "${guard}" ] && printf "#if ${guard}\n" cat <<EOF -static inline ${ret} +static __always_inline ${ret} ${atomicname}(${params}) { ${checks} @@ -107,7 +107,7 @@ cat <<EOF #define ${xchg}(ptr, ...) \\ ({ \\ typeof(ptr) __ai_ptr = (ptr); \\ - kasan_check_write(__ai_ptr, ${mult}sizeof(*__ai_ptr)); \\ + instrument_atomic_write(__ai_ptr, ${mult}sizeof(*__ai_ptr)); \\ arch_${xchg}(__ai_ptr, __VA_ARGS__); \\ }) EOF @@ -147,7 +147,8 @@ cat << EOF #define _ASM_GENERIC_ATOMIC_INSTRUMENTED_H #include <linux/build_bug.h> -#include <linux/kasan-checks.h> +#include <linux/compiler.h> +#include <linux/instrumented.h> EOF diff --git a/scripts/atomic/gen-atomic-long.sh b/scripts/atomic/gen-atomic-long.sh index c240a7231b2e..e318d3f92e53 100755 --- a/scripts/atomic/gen-atomic-long.sh +++ b/scripts/atomic/gen-atomic-long.sh @@ -46,7 +46,7 @@ gen_proto_order_variant() local retstmt="$(gen_ret_stmt "${meta}")" cat <<EOF -static inline ${ret} +static __always_inline ${ret} atomic_long_${name}(${params}) { ${retstmt}${atomic}_${name}(${argscast}); @@ -64,6 +64,7 @@ cat << EOF #ifndef _ASM_GENERIC_ATOMIC_LONG_H #define _ASM_GENERIC_ATOMIC_LONG_H +#include <linux/compiler.h> #include <asm/types.h> #ifdef CONFIG_64BIT diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl index 197436b20288..cfb5d42c54de 100755 --- a/scripts/checkpatch.pl +++ b/scripts/checkpatch.pl @@ -5945,6 +5945,14 @@ sub process { } } +# check for data_race without a comment. + if ($line =~ /\bdata_race\s*\(/) { + if (!ctx_has_comment($first_line, $linenr)) { + WARN("DATA_RACE", + "data_race without comment\n" . $herecurr); + } + } + # check for smp_read_barrier_depends and read_barrier_depends if (!$file && $line =~ /\b(smp_|)read_barrier_depends\s*\(/) { WARN("READ_BARRIER_DEPENDS", diff --git a/tools/objtool/check.c b/tools/objtool/check.c index 63d65a702900..5fbb90a80d23 100644 --- a/tools/objtool/check.c +++ b/tools/objtool/check.c @@ -505,6 +505,28 @@ static const char *uaccess_safe_builtin[] = { "__asan_report_store4_noabort", "__asan_report_store8_noabort", "__asan_report_store16_noabort", + /* KCSAN */ + "__kcsan_check_access", + "kcsan_found_watchpoint", + "kcsan_setup_watchpoint", + "kcsan_check_scoped_accesses", + "kcsan_disable_current", + "kcsan_enable_current_nowarn", + /* KCSAN/TSAN */ + "__tsan_func_entry", + "__tsan_func_exit", + "__tsan_read_range", + "__tsan_write_range", + "__tsan_read1", + "__tsan_read2", + "__tsan_read4", + "__tsan_read8", + "__tsan_read16", + "__tsan_write1", + "__tsan_write2", + "__tsan_write4", + "__tsan_write8", + "__tsan_write16", /* KCOV */ "write_comp_data", "check_kcov_mode", |