lwn.git/kernel/trace/ftrace.c, branch docs-5.16-3

Merge tag 'trace-v5.16-3' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

2021-11-11T18:16:33+00:00

Pull tracing fixes from Steven Rostedt: "Two locking fixes: - Add mutex protection to ring_buffer_reset() - Fix deadlock in modify_ftrace_direct_multi()" * tag 'trace-v5.16-3' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: ftrace/direct: Fix lockup in modify_ftrace_direct_multi ring-buffer: Protect ring_buffer_reset() from reentrancy

ftrace/direct: Fix lockup in modify_ftrace_direct_multi

2021-11-10T16:56:43+00:00

We can't call unregister_ftrace_function under ftrace_lock. Link: https://lkml.kernel.org/r/20211109114217.1645296-1-jolsa@kernel.org Fixes: ed29271894aa ("ftrace/direct: Do not disable when switching direct callers") Signed-off-by: Jiri Olsa Signed-off-by: Steven Rostedt (VMware)

Merge branch 'akpm' (patches from Andrew)

2021-11-09T18:11:53+00:00

Merge more updates from Andrew Morton: "87 patches. Subsystems affected by this patch series: mm (pagecache and hugetlb), procfs, misc, MAINTAINERS, lib, checkpatch, binfmt, kallsyms, ramfs, init, codafs, nilfs2, hfs, crash_dump, signals, seq_file, fork, sysvfs, kcov, gdb, resource, selftests, and ipc" * emailed patches from Andrew Morton : (87 commits) ipc/ipc_sysctl.c: remove fallback for !CONFIG_PROC_SYSCTL ipc: check checkpoint_restore_ns_capable() to modify C/R proc files selftests/kselftest/runner/run_one(): allow running non-executable files virtio-mem: disallow mapping virtio-mem memory via /dev/mem kernel/resource: disallow access to exclusive system RAM regions kernel/resource: clean up and optimize iomem_is_exclusive() scripts/gdb: handle split debug for vmlinux kcov: replace local_irq_save() with a local_lock_t kcov: avoid enable+disable interrupts if !in_task() kcov: allocate per-CPU memory on the relevant node Documentation/kcov: define `ip' in the example Documentation/kcov: include types.h in the example sysv: use BUILD_BUG_ON instead of runtime check kernel/fork.c: unshare(): use swap() to make code cleaner seq_file: fix passing wrong private data seq_file: move seq_escape() to a header signal: remove duplicate include in signal.h crash_dump: remove duplicate include in crash_dump.h crash_dump: fix boolreturn.cocci warning hfs/hfsplus: use WARN_ON for sanity check ...

sections: move and rename core_kernel_data() to is_kernel_core_data()

2021-11-09T18:02:50+00:00

Move core_kernel_data() into sections.h and rename it to is_kernel_core_data(), also make it return bool value, then update all the callers. Link: https://lkml.kernel.org/r/20210930071143.63410-4-wangkefeng.wang@huawei.com Signed-off-by: Kefeng Wang Reviewed-by: Sergey Senozhatsky Cc: Arnd Bergmann Cc: Steven Rostedt Cc: Ingo Molnar Cc: "David S. Miller" Cc: Alexander Potapenko Cc: Alexei Starovoitov Cc: Andrey Konovalov Cc: Andrey Ryabinin Cc: Benjamin Herrenschmidt Cc: Borislav Petkov Cc: Christophe Leroy Cc: Dmitry Vyukov Cc: Ivan Kokshaysky Cc: Matt Turner Cc: Michael Ellerman Cc: Michal Simek Cc: Paul Mackerras Cc: Petr Mladek Cc: Richard Henderson Cc: Thomas Gleixner Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

Merge tag 'trace-v5.16' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

2021-11-02T03:05:19+00:00

Pull tracing updates from Steven Rostedt: - kprobes: Restructured stack unwinder to show properly on x86 when a stack dump happens from a kretprobe callback. - Fix to bootconfig parsing - Have tracefs allow owner and group permissions by default (only denying others). There's been pressure to allow non root to tracefs in a controlled fashion, and using groups is probably the safest. - Bootconfig memory managament updates. - Bootconfig clean up to have the tools directory be less dependent on changes in the kernel tree. - Allow perf to be traced by function tracer. - Rewrite of function graph tracer to be a callback from the function tracer instead of having its own trampoline (this change will happen on an arch by arch basis, and currently only x86_64 implements it). - Allow multiple direct trampolines (bpf hooks to functions) be batched together in one synchronization. - Allow histogram triggers to add variables that can perform calculations against the event's fields. - Use the linker to determine architecture callbacks from the ftrace trampoline to allow for proper parameter prototypes and prevent warnings from the compiler. - Extend histogram triggers to key off of variables. - Have trace recursion use bit magic to determine preempt context over if branches. - Have trace recursion disable preemption as all use cases do anyway. - Added testing for verification of tracing utilities. - Various small clean ups and fixes. * tag 'trace-v5.16' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (101 commits) tracing/histogram: Fix semicolon.cocci warnings tracing/histogram: Fix documentation inline emphasis warning tracing: Increase PERF_MAX_TRACE_SIZE to handle Sentinel1 and docker together tracing: Show size of requested perf buffer bootconfig: Initialize ret in xbc_parse_tree() ftrace: do CPU checking after preemption disabled ftrace: disable preemption when recursion locked tracing/histogram: Document expression arithmetic and constants tracing/histogram: Optimize division by a power of 2 tracing/histogram: Covert expr to const if both operands are constants tracing/histogram: Simplify handling of .sym-offset in expressions tracing: Fix operator precedence for hist triggers expression tracing: Add division and multiplication support for hist triggers tracing: Add support for creating hist trigger variables from literal selftests/ftrace: Stop tracing while reading the trace file by default MAINTAINERS: Update KPROBES and TRACING entries test_kprobes: Move it from kernel/ to lib/ docs, kprobes: Remove invalid URL and add new reference samples/kretprobes: Fix return value if register_kretprobe() failed lib/bootconfig: Fix the xbc_get_info kerneldoc ...

ftrace: Fix kernel-doc formatting issues

2021-10-29T13:52:23+00:00

Some functions had kernel-doc that used a comma instead of a hash to separate the function name from the one line description. Also, the "ftrace_is_dead()" had an incomplete description. Signed-off-by: Steven Rostedt (VMware)

ftrace: disable preemption when recursion locked

2021-10-27T15:21:49+00:00

As the documentation explained, ftrace_test_recursion_trylock() and ftrace_test_recursion_unlock() were supposed to disable and enable preemption properly, however currently this work is done outside of the function, which could be missing by mistake. And since the internal using of trace_test_and_set_recursion() and trace_clear_recursion() also require preemption disabled, we can just merge the logical. This patch will make sure the preemption has been disabled when trace_test_and_set_recursion() return bit >= 0, and trace_clear_recursion() will enable the preemption if previously enabled. Link: https://lkml.kernel.org/r/13bde807-779c-aa4c-0672-20515ae365ea@linux.alibaba.com CC: Petr Mladek Cc: Guo Ren Cc: Ingo Molnar Cc: "James E.J. Bottomley" Cc: Helge Deller Cc: Michael Ellerman Cc: Benjamin Herrenschmidt Cc: Paul Mackerras Cc: Paul Walmsley Cc: Palmer Dabbelt Cc: Albert Ou Cc: Thomas Gleixner Cc: Borislav Petkov Cc: "H. Peter Anvin" Cc: Josh Poimboeuf Cc: Jiri Kosina Cc: Joe Lawrence Cc: Masami Hiramatsu Cc: Nicholas Piggin Cc: Jisheng Zhang CC: Steven Rostedt CC: Miroslav Benes Reported-by: Abaci Suggested-by: Peter Zijlstra Signed-off-by: Michael Wang [ Removed extra line in comment - SDR ] Signed-off-by: Steven Rostedt (VMware)

ftrace: Make ftrace_profile_pages_init static

2021-10-26T02:27:07+00:00

This symbol is not used outside of ftrace.c, so marks it static. Fixes the following sparse warning: kernel/trace/ftrace.c:579:5: warning: symbol 'ftrace_profile_pages_init' was not declared. Should it be static? Link: https://lkml.kernel.org/r/1634640534-18280-1-git-send-email-jiapeng.chong@linux.alibaba.com Reported-by: Abaci Robot Fixes: cafb168a1c92 ("tracing: make the function profiler per cpu") Signed-off-by: chongjiapeng Signed-off-by: Steven Rostedt (VMware)

ftrace/direct: Do not disable when switching direct callers

2021-10-21T18:19:00+00:00

Currently to switch a set of "multi" direct trampolines from one trampoline to another, a full shutdown of the current set needs to be done, followed by an update to what trampoline the direct callers would call, and then re-enabling the callers. This leaves a time when the functions will not be calling anything, and events may be missed. Instead, use a trick to allow all the functions with direct trampolines attached will always call either the new or old trampoline while the switch is happening. To do this, first attach a "dummy" callback via ftrace to all the functions that the current direct trampoline is attached to. This will cause the functions to call the "list func" instead of the direct trampoline. The list function will call the direct trampoline "helper" that will set the function it should call as it returns back to the ftrace trampoline. At this moment, the direct caller descriptor can safely update the direct call trampoline. The list function will pick either the new or old function (depending on the memory coherency model of the architecture). Now removing the dummy function from each of the locations of the direct trampoline caller, will put back the direct call, but now to the new trampoline. A better visual is: [ Changing direct call from my_direct_1 to my_direct_2 ] : call my_direct_1 |||||||||||||||||||| vvvvvvvvvvvvvvvvvvvv : call ftrace_caller : [..] call ftrace_ops_list_func ftrace_ops_list_func() { ops->func() -> direct_helper -> set rax to my_direct_1 or my_direct_2 } call rax (to either my_direct_1 or my_direct_2 |||||||||||||||||||| vvvvvvvvvvvvvvvvvvvv : call my_direct_2 Link: https://lore.kernel.org/all/20211014162819.5c85618b@gandalf.local.home/ Acked-by: Jiri Olsa Signed-off-by: Steven Rostedt (VMware)

ftrace: Add multi direct modify interface

2021-10-21T18:19:00+00:00

Adding interface to modify registered direct function for ftrace_ops. Adding following function: modify_ftrace_direct_multi(struct ftrace_ops *ops, unsigned long addr) The function changes the currently registered direct function for all attached functions. Link: https://lkml.kernel.org/r/20211008091336.33616-8-jolsa@kernel.org Signed-off-by: Jiri Olsa Signed-off-by: Steven Rostedt (VMware)