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6 daysMerge tag 'mm-nonmm-stable-2026-10-25-14-57' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Pull non-MM updates from Andrew Morton: - "ocfs2: exit recovery thread on mount error path" (Joseph Qi): Stop OCFS2 recovery before freeing failed-mount state and replay slots, closing use-after-free and double-free races. Defer suballocator reclaim to break a transaction-lock deadlock with dismount. - "ocfs2: validate suballoc slot and bit of metadata blocks" (Joseph Qi): Validate OCFS2 metadata suballocator slots, bits and directory index block locations. Reject corrupt metadata with filesystem errors instead of BUGs or out-of-bounds accesses. - "ocfs2: deal with legacy signed name hash values" (Joseph Qi): Restore OCFS2 lookups for non-ASCII names stored with legacy signed hashes. Use stored xattr hashes during bucket splits to avoid duplicate entries and spurious ENOSPC failures. - "ocfs2: stabilize dentry names in file and setattr traces" (Cen Zhang): Snapshot OCFS2 names during file and setattr tracing to prevent rename races using freed storage or mismatched names and lengths. Preserve trace formats and the locked release open-count sample. - "panic: fix panic_force_cpu= redirect races and NMI bypass" (Bradley Morgan): Fix panic_force_cpu races and NMI redirection so crash-kernel CPU selection is honored. Preserve variable arguments on failed redirects and use a static message buffer. - "fat: allocate multiple clusters in fallocate" (Matheus Alves de Almeida): Allocate FAT clusters in batches for FALLOC_FL_KEEP_SIZE and batch FAT updates. This removes repeated single-cluster allocation overhead, particularly on synchronous mounts. - "scripts/gdb: fix radix tree lookup and stack depot diagnostic" (Ting-Han Hou): Fix GDB radix-tree lookup and its handling of XArray sibling, retry and zero entries. Also repair the stack-depot diagnostic for an out-of-range pool index. - "hung_task: Improve warning budget handling and task reporting" (Aaron Tomlin): Reset the hung-task warning budget after recovery so later hangs remain visible. Keep the configured limit intact and emit one summary per scan when detailed reports exhaust the budget. - "bootconfig: Reject unexpected data after null character and cleanups" (Masami Hiramatsu): Reject bootconfig data after an embedded null while accepting trailing padding. Validate the full input in the userspace tool, and retain internal tree sanity checks there rather than in the kernel. - "kbuild: GCOV cleanups following the prefer-atomic fix" (Konstantin Khorenko): Use the actual GCOV build flags in the prefer-atomic compiler probe. Move flag setup into scripts/Makefile.gcov and skip the probe when GCOV is disabled. - "ocfs2: xattr bucket validation fixes" (Joseph Qi): Accept valid OCFS2 xattr buckets spanning 512-byte blocks, avoiding false read-only remounts. Reject misaligned buckets and return errors instead of panicking on corrupt defrag metadata. - "ocfs2: fix metadata reservation for xattr value trees" (Joseph Qi): Reserve enough OCFS2 metadata for new and relocated xattr value trees. Fix shortfalls which could cause ENOSPC, dropped entries and leaked clusters on fragmented filesystems; remove duplicate reservations. - "Introduce arch_do_panic" (Mete Durlu): Add arch_do_panic() and move s390 and sparc handling out of generic panic code. The architecture-specific actions now follow the end-of-panic marker. - "checkpatch: userspace improvements" (Petr Vorel): Improve checkpatch's userspace detection and suppress kernel-only checks. Recognize standard inttypes macros and add explicit --userspace and --no-userspace overrides. - "ocfs2: validate dr_fs_generation of dir index root blocks" (Joseph Qi): Check OCFS2 directory index generations and leaf block numbers. Reject stale or misplaced blocks instead of using metadata left by a previously formatted filesystem. - "selftests/membarrier: Skip an unregistered memory barrier test on Musl" (Chris Gellermann): Skip the unregistered membarrier test when libc has already registered the command. Musl does this during thread creation, causing false failures in the multithreaded test. - "init: fix array boundary bugs in boot parameter parsing" (Wilson Felipe Pereira): Fix boot argument boundary cases which leave stale arguments in init's command line or panic when replacing the final environment variable. Clear the last slot and check duplicates before the limit. Summary of the 87 singletons in this merge: The OCFS2 singletons fix deadlocks between xattr updates and inline truncation, and during inode reclaim. Corrupt quota and extent metadata could also crash the kernel or corrupt memory; these paths now check the layout before using it. Other fixes close use-after-free and publication races around cluster reconfiguration, node failure, quota remount errors and shared refcount trees. New files now retain security labels from all stacked LSMs instead of silently dropping all but one. Valid xattr insertions also stop tripping FORTIFY on builds with counted arrays. Elsewhere, a lost wakeup could leave hardware-monitoring reads stuck in unkillable sleep and block further I2C traffic. That is fixed, as are kernel memory leaks in POSIX message-queue notifications and tmpfs casefold setup which could grow until memory is exhausted. A driver removal race which could crash the kernel is fixed too. The hibernation command through reboot() also stops taking the same mutex twice, avoiding a deadlock before suspension. On the boot side, bzip2 decoding now accepts valid full blocks emitted by lbzip2, fixing failures to boot those compressed kernels. Malformed bzip2 streams can no longer overflow the decode buffer, and LZ4 initrds are checked before the decoder can read past their end. FAT rejects geometry which overflows the data-area calculation on 32-bit systems, and rolls back entries when inode setup fails, preventing failed creations from reappearing after remount. The x86 XOR and RAID6 AVX paths also avoid imposing a slowdown on subsequent SSE code. * tag 'mm-nonmm-stable-2026-10-25-14-57' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (134 commits) scripts/gdb: fix stack depot out-of-bounds diagnostic scripts/gdb: fix radix tree lookup pointer handling ocfs2/cluster: remove zero-address nodes from IP tree on teardown ocfs2: snapshot the dentry name while tracing file release ocfs2: snapshot dentry names in file and setattr traces ocfs2/dlm: drain join handlers before releasing module text MAINTAINERS: update Markus's e-mail address mailmap: add entries for Andrew Jones stackdepot: stop preallocating after the final pool ocfs2: drain quorum work before removing the cluster watchdog: force console verbose when reporting lockups profiling: fix sampling step on 64-bit big-endian systems kernel/reboot: avoid potential deadlocks during suspension compat: avoid double rounding in times() ocfs2: pin owning modules for open debugfs files ocfs2/cluster: initialize heartbeat regions before publishing them selftests/proc: proc-pid-vm: fix unused variable warning on non-x86 ocfs2: pin refcount trees before dropping the lookup lock ocfs2: validate the xattr tree root of an indexed xattr block ocfs2/dlm: hold the lookup reference across convert AST enqueue ...
10 daysMerge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds
Pull KVM updates from Paolo Bonzini: "ARM: - pKVM state isolation: years after pKVM started being enabled upstream, we finally get the basics in the form of state isolation. The vcpu state is now off-limit for the host for protected VMs - pKVM also grows a hypervisor-private memory allocator, allowing it to deal with sub-page allocation, much like everywhere else - pKVM also lands a trace_printk() equivalent, which hopefully will make debugging a bit easier - First shot at annotating portions of the KVM/arm64 code to be extracted and built on s390. The real fun is yet to come - Allow pre-faulting of stage-2 canonical mappings from userspace, joining x86 and s390 in implementing this feature - Add a reverse mapping infrastructure for shadow stage-2, significantly improving performance when MMU notifiers kick in, and avoiding full unmap of all shadow tables for this VM - Next step of GICv5 enablement, adding support for the IRS block, and providing both SPI and LPI support. This is the first point where KVM/arm64 can support an SMP GICv5 guest - As a preliminary to eventually enabling CCA, add a bunch of infrastructure to KVM/arm64, splitting some of the basic operations into individual backends (normal VM, normal pKVM VM, protected pKVM VM). This allows CCA to later slot in without polluting the rest of KVM with its firmware-driven nonsense - Make ID registers immutable from the point where a vcpu is able to run, even if it fails to run. This prevents KVM from sampling untrusted values - Restore some type checking to the EL2 object. KVM/arm64 originally had some strong type checking between the kernel and the EL2 object, but lost it along the way when the private hypercall interface was (somewhat pointlessly) converted to SMCCC. Type checking is back, syscall style, and with added sparse goodies - Expand the FFA support to FFA_NOTIFICATION_*, and add some sanitisation of the protocol that pKVM relays to the "trusted" runtime - Make GICv3 RD assignment more robust to userspace nonsense - Convert the remaining MMU fault handler backends to kvm_s2_fault_vma_info and co., fixing a number of bugs in the process - Fix the SError/SEA selftests to be both more robust and less braindead - Fix a smattering of documentation bugs, some of them as a result of our AI friends spitting out credible assertions based on non-existing symbols - The usual collection of low impact bug fixes (SMCCC, timers, PMU) Loongarch: - Add separate vmid support - Simplify MSI interrupt injection - Add crash hypercall support - Allow to set pv_feature until vCPU run - Enable HW page table walk automatically in selftests s390: - rework page allocation for secure guest variable storage - Selftests and documentation improvements - Replace get_zeroed_page with kzalloc - Fix corner cases of floating interrupt injection - Initial arm64 on s390 support x86: - Clean up the handling of vcpu->arch.xen.long_mode to be consistent and correctly handle 32-bit/64-bit alignment, and various other bug fixes have accumulated over the months since v1 - Grab KVM's SRCU "lock" in kvm_zap_gfn_range() to fix a recurring bug where callers fail to do so - Fix a variety of issues in the pre-fault code that are mostly benign in the current code base, but will show up in big ways if/when the pre-faulting logic is used to implementing prefetch-on-fault for the TDP MMU - For PREEMPT_RT=y kernels, drop the rmaps' individual bit-spinlock and just walk the rmaps' with mmu_lock taken. On the write side (which always uses mmu_lock), the bit-spinlock was assuming that preemption was disabled, but that is *not* true when rwlocks become sleepable - Prepare a memory_fault exit (paired with -EFAULT) when KVM hits an error PFN, e.g. so that userspace can resolve transient issues instead of killing the guest. Convert a variety of WARN()+EFAULT paths into KVM_BUG_ON()+EIO so that KVM can hard commit to filling memory_fault on -EFAULTs that occur in the page fault path - Fix a NX hugepage un-accounting bug where KVM would always uncharge the shadow MMU, even when handling TDP MMU pages - Mask off the address space ID when checking for illegal usage of kvm_set_internal_memslot() to prevent false negatives on the sanity check - Explicitly zero reserved flags when delivering a SynIC message to avoid leaking a byte of stack information to the guest - Rework TDX's handling of the canonical MMU root level to not rely on userspace to fill CPUID correctly, as doing so lets userspace trivially trigger a KVM_BUG_ON() - Reject KVM_SET_NESTED_STATE if userspace "restores" L1 with EFER.LMA=1 && EFER.LME=0, which confuses KVM into trying to configure an 64-bit MMU without PAE - Ignore EFER.LMA (clear it from KVM's cached save state) if EFER.LME=0 when preparing L2 state, to fix another way to confuse KVM's MMU (and because real hardware also ignores EFER.LMA) - Improve KVM's sanity checks for a misconfigured MMU to (hopefully) detect all of the ways KVM can botch EFER.LMA vs. CR4.PAE - Remove the "full" out-param from kvm_x86_ops.flush_tlb_gva() as the param is only used to avoid what effectively amounts to a single memory write - Fix a mostly-benign bug where KVM can write through a guest's read-only mapping due to not checking the error code when expediting emulated MMIO page faults - Honor the guest's view of the "EFER.LMSLE must be zero" defeature so that userspace can provide migration compatibility between Rome and Milan+ - Pend a KVM_REQ_EVENT request when an exception is morphed into a nested VM-Exit, otherwise KVM can fail to actually deliver the nested VM-Exit, e.g. when injecting a page fault - Add support for PML on SVM - Add support for virtualizing Bus Lock Detect on SVM, and fix a number of DR6 bugs and warts along the way - Fix a variety of warts in KVM's handling of guest TSC, kvmclock, and timekeeping in general, as a (big) first step towards addressing several longstanding problems with the kvmclock implementation. Most notably, fix a precision issue where get_kvmclock_ns() computed the clock from the *host* TSC without applying guest TSC scaling, causing systemic drift from the values the guest computes from its own TSC - Rip out KVM's shadow timekeeping structures, now that ktime snapshots are powerful enough to replace it - Misc fixes and cleanups x86 (AMD): - Fix a benign-in-practice bug where KVM unintentionally sets a non-zero error code when delivering exceptions to SEV-ES+ guests - Force a new ASID in both VMCBs on pCPU migration to fix a bug where KVM can run a VMCB with a stale ASID due to the tracking being per-CPU, not per-VMCB - Return INVALID_INPUT to the guest instead of exiting to userspace with -EIO if KVM can't access "guest request" buffer, i.e. try to keep the guest alive if the guest or userspace goofs x86 (Intel): - Enable Notify VM-Exits (now called Instruction Timeout in the SDM) and Bus Lock VM-Exits for TDX guests when they're enabled by userspace (KVM forgot to wire up the TDX Module knobs) - Move all common (between VMX and TDX) APIs/helpers to common.h/main.c, and change all namespace prefixes from "vmx" to "vt" - Fix a thankfully benign bug (due to other areas of KVM being hardened) where userspace can bypass INIT_MEM_REGION's address wrap check by providing a nr_pages that will overflow a u64 when converted to bytes, and fix an also- benign off-by-one bug in the check (inclusive vs. exclusive) - Set the vmcs.GUEST_ACTIVITY_STATE back to ACTIVE when userspace sets KVM's mp_state to anything other than HALTED, e.g. so that a vCPU doesn't get stuck in HLT if userspace emulates RESET guest_memfd: - Take the invalidate lock when unbinding a dying file to fix a race with kvm_gmem_invalidate_end() that results in KVM leaving the MMU invalidation count elevated. Not taking the lock in the first place was pure misguided paranoid - When binding a memslot, purge the bindings if storing the new memslot fails, as Xarray's "store range" API can subtly fail partway through - Establish memslot<=>guest_memfd bindings *after* the memslot is ready, as the memslot becomes reachable the instant the binding is installed - Don't grab a page refcount when reloading an SNP VMSA and stop returning a "struct page" from guest_memfd's PFN lookup altogether, to ensure that KVM doesn't hold any unnecessary refcounts (the lifetime of the page is ensured by MMU notifiers and similar hooks). Preventing unnecessary refcounts greatly simplifies supporting in-place SHARED=>PRIVATE conversions - Add support for in-place PRIVATE<=>SHARED conversion, i.e. allow a single guest_memfd instance to be used for both PRIVATE and SHARED variations of CoCo guests' memory (though not at the same time). This eliminates the need to double allocate guest memory for TDX and SNP, and is basically a hard requirement for pKVM, which relies on being able to preserve memory contents on conversions - Hack-a-fix a deadlock bug in ->error_remove_folio() by returning -EBUSY if the filemap invalidate lock is contended. Punt on a proper fix for the moment, as a proper fix likely involves reworking truncate_error_folio() - Add a pile of selftests for in-place conversions - Misc guest_memfd cleanups Generic: - Move some configuration items to preprocessor symbols, to help with arm-on-s390's need to compile the same code twice with different values - Allow KVM implementations to choose alternative device names, also for s390's support of ARM virtualmachines - Switch the KVM-VFIO interface and external consumers over to standard file-based reference counting, eliminating all external KVM symbol exports Selftests: - Rework KVM selftest's handling of memory regions all so that PPC can force its page table allocations to be naturally aligned - PPC support - Fix emulation of VMPTRST and VMPTRLD when eVMCS is in-use to match real Hyper-V's behavior - Saturate L2's TSC frequency if stacking L1 and L2 scaling multipliers exceeds what hardware supports, as attempting to run L2 with an illegal multiplier will either cause VM-Entry to fail (VMX) or trigger a #GP when writing MSR_AMD64_TSC_RATIO (SVM). The #GP is thankfully benign in the grand scheme as even "unsafe" WRMSRs have exception fixup - Rework KVM selftest's handling of memory regions so that PPC can force its page table allocations to be naturally aligned - Clean up selftest's VMX instruction helpers, and drop an absurd number of completely useless return values, e.g. functions that unconditionally return %true and then have every caller assert success - Add selftests support for Zhaoxin CPUs - Overhaul the TSC scaling test to add a regression test for the saturation behavior, and to increase its coverage in general - Fix selftests usage various NUMA syscalls to account for an undocumented, but known since 2007, off-by-one kernel bug. Add helpers to try and avoid re-introducing the same flaws in the future - Automatically run xAPIC IPI migration test (between NUMA nodes) when possible, as the entire point of the test is verify KVM's handling of page migration of the APIC backing page - Misc cleanups" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (506 commits) KVM: always make in-place conversion a compile-time constant when possible KVM: x86: leave the legacy private attribute in for TDX and SEV KVM: split CONFIG_KVM_PRIVATE_MEMATTR_VM out of KVM_VM_MEMORY_ATTRIBUTES selftests: kvm: remove useless comma operator arm64: Use proper include variant MAINTAINERS: Add entry for ARM on s390 KVM KVM: s390: arm64: Integrate arm on s390 KVM: s390: arm64: Implement basic page fault handler KVM: s390: arm64: Implement vCPU IOCTLs KVM: s390: arm64: Implement vm/vcpu create destroy KVM: s390: arm64: Implement required functions KVM: s390: Add basic arm64 kvm module s390/hwcaps: Report SAE support as hwcap KVM: s390: arm64: Introduce host definitions s390: Introduce Start Arm Execution instruction KVM: s390: Use arm64 code s390/tools: Use arm64 headers KVM: s390: Use dedicated function for migration mode s390/Kconfig: remove PCI dependency from HAS_IOMEM KVM: s390: Kick PV cpus at the right time for service irqs ...
12 daysMerge tag 'timers-vdso-2026-10-20' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull VDSO updates from Thomas Gleixner: "Updates for the VDSO subsystem: - Ensure that the CLOCK_AUX base calculations are properly scaled against the base timekeeper. The update function failed to take the fractional nanosecond part into account, which results in a rounding error. - Cleanup and consolidate the vsyscall headers to get rid of pointless copies all over the architectures. - Replace a runtime conditional in the time getter function for namespaced clocks by simple pointer arithmetic which speeds up the read function" * tag 'timers-vdso-2026-10-20' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: vdso/vsyscall: Keep the CLOCK_AUX base scaled vdso/math64: Add and use __iter_div64_u64_rem() vdso/math64: Use OPTIMIZER_HIDE_VAR() in __iter_div_u64_rem() vdso/gettimeofday: Avoid runtime conditional in do_hres_timens() vdso: Remove __ASSEMBLER__ guards from vsyscall.h vdso: Add asm-generic/vdso/vsyscall.h vdso: Remove unnecessary vdso/vsyscall.h includes riscv/hwprobe: Include vdso/datapage.h arm64/vdso: Delete asm/vdso/vsyscall.h inclusions x86/vdso: Delete asm/vdso/vsyscall.h inclusions sparc/vdso: Delete asm/vdso/vsyscall.h inclusion s390/vdso: Delete asm/vdso/vsyscall.h inclusions sparc/vdso: Move __VDSO_PAGES to asm/vdso.h x86/vdso: Move vDSO page definitions to asm/vdso.h vdso: Delete asm-generic/vdso/vsyscall.h vdso/vsyscall: Define fallback time synchronization functions in vsyscall.c vdso/getrandom: Define fallback __arch_get_vdso_u_rng_data() in getrandom.c vdso/gettimeofday: Define fallback __arch_get_vdso_u_time_data() in gettimeofday.c vdso: Move the kernel-side time update helpers to a new header
12 daysMerge __{get,put}_user() removal branchLinus Torvalds
This is long over-due: the __get_user() and __put_user() functions are entirely historical, and are never the rigth thing to use any more. And when mis-used (read: every case) they are not only slower than the right thing, but also insecure because they don't check the user address range. Most of the usage sites have been converted long ago, but various left-overs remained. So this started out as a single patch that I wrote as a "show people how to convert __{get,put}_user() to modern code". In particular, Thomas last year implemented the very nice new scoped user access region helpers (see commit e497310b4ffb: "uaccess: Provide scoped user access regions") that makes the modern interfaces particularly easy to use and really removes any excuse for the old horrors. That small example patch then grew to this, partly using Claude as a glorified coccinelle script to apply the pattern to other places. There were a few different reasons for using __put_user() and __get_user() rather than the alternatives, but the original historical one was performance: when doing multiple accesses off the same base pointer, doing a single range check followed by multiple non-checked accesses used to create smaller and faster code. The keyword here is "used to". It hasn't been true for years, because the range check isn't actually the real cost these days. The real cost of user accesses on modern hardware is turning the user accesses on and off in the first place (on x86, using the STAC/CLAC instructions). Those sequences get turned into 'scoped_user_read_access() { }' blocks, see for example that first patch in the series: "signal: use scoped user access for old-style sigaction". Another, historical reason for using __get_user() and friends is that you actually want to do a kernel pointer access, but the pointer might not be entirely reliable (typically during fault handling), so you want to have exception handling for the kernel access. The modern way to do that kind of non-faulting kernel access is using "get_kernel_nofault()", but some code predates that helper existing at all, and used __get_user() as a way to just get a memory access with exception handling. For that pattern, see for example "alpha: use get_kernel_nofault() in dik_show_code()" A third bad reason for using __get_user() and friends was that the proper get_user() had a "might_fault()" in it, and code that ran in atomic regions but hadn't disabled page faults would result in a warning. That kind of code needs to explicitly disable page faults, because "atomic region" is not well defined at run-time and can be invisible (eg a preempt-off region in a non-preemptible kernel). See "vdpa_sim: disable page faults around vringh_need_notify_iotlb()" for an example of that pattern, where the local_bh_disable() now also grows a pagefault_disable(), which makes the normal get_user() no longer warn about the user access in non-process context, because it can see that the potential page fault will not cause problems. And finally, the really nasty reason to use __get_user() and friends: pointers that can be either kernel pointers or user pointers. We've gotten rid of almost all such cases, but a couple remained. See for example "x86/sev: Use explicit user-or-kernel accessors for #VC memory operands". NOTE! This series removes all __get/put_user() calls from generic code but only does the final removal of the whole interface on x86. Other architectures have not been entirely converted, for a variety of reasons: - arm64 makes __{get,put}_user() be exactly the same as {get,put}_user() so it's harmless and didn't have the dangers of the legacy use cases. - any architecture that uses <asm-generic/uaccess.h> will still use __{get,put}_user as the underlying helper function name - several architectures had some legacy uses that weren't entirely trivial and I didn't want to extend this patch series to things that I don't know and that don't really matter. but I did do a couple of the obvious "follows the exact same pattern" just because it could be done mindlessly and automatically. Let's see if I broke anything, but we should have done this years ago. * uaccess-cleanups: (48 commits) drm/i915/gem: ignore errors on presumed_offset write-back powerpc/align: use get_user_instr() for a user-mode instruction powerpc/signal64: use scoped user access in setup_trampoline() powerpc/signal64: use get_user() for the single context reads powerpc/signal32: use get_user() for the single context reads KVM: PPC: Book3S HV: use get_user()/put_user() for the HPT fd powerpc/powernv: use get_user()/put_user() in the LPC debugfs files s390: use get_user()/put_user() instead of the unchecked variants ARM: OABI: use scoped user access in epoll_put_uevent() ARM: signal: stop using __put_user() for the signal frame ARM: signal: check the FDPIC function descriptor address alpha: split the prefetch check in do_page_fault() by mode openrisc: use get_kernel_nofault() in show_registers() alpha: use get_kernel_nofault() in dik_show_code() nios2: use scoped user access for the signal frame nios2: check the signal frame address before writing to it hexagon: use scoped user access for the signal frame alpha: use scoped user access when setting up signal frames alpha: use scoped user access in the sigreturn path alpha: use scoped user access in osf_sigaction() ...
12 daysMerge tag 's390-7.4-1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux Pull s390 updates from Heiko Carstens: - Add support for sclp-vt220 terminal resize events e.g. for QEMU - Warn if kernel command line contains non-printable EBCDIC characters - Improve show_code() disassembly output by using reliable markers for the instruction address and faulting instruction - Rework exception handling to require only a single exception table entry per faulting instruction: convert all inline assemblies from EX_TABLE to the new EX_TABLE_INSN macros. The previous exception handling was error prone since it usually required two EX_TABLE entries: one pointing at the instruction, and one pointing behind it - Disallow kprobes on instructions with exception table entries to avoid exception handlers decoding a breakpoint instead of the original instruction - Preemptible percpu ops changes: - Simplify percpu_entry() and percpu_exit() by encoding the percpu base, offset, and pointer registers into the lowcore marker, allowing percpu_exit() to update the percpu pointer on CPU migration without comparing the interrupted instruction - Convert this_cpu_cmpxchg(), this_cpu_xchg(), and this_cpu_cmpxchg128() to preemptible percpu ops; provide this_cpu_try_cmpxchg() - Emulate virtual timer in appldata via delayed work and remove the s390 specific vtimer infrastructure - Add lock contention tracepoints to rwlock slowpath - Fix incorrect return address in signal frame setup - Fix cpum_cf CPU hotplug handling - Convert various __get_free_pages() / get_zeroed_page() users to kmalloc() / kzalloc() - PCI: - Improve RPCIT instruction tracing - Fix double-free, use-after-free, and resource leaks in zPCI MSI and IRQ setup / cleanup paths - Crypto and zcrypt: - Improve reply message and length verification checks for CCA, EP11, and ICA messages to prevent out-of-bounds reads - Add missing array_index_nospec() for domain index uses in zcrypt to prevent speculative execution bypass - Fix out-of-bounds read in cca_query_crypto_facility() - Various other small fixes and improvements * tag 's390-7.4-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (102 commits) s390/signal: Cleanup coding style s390/signal: Fix incorrect return address in signal frame s390/probes: Fix wrong mnemonic comment for clgib s390/probes: Add missing fixup for bctgr and bic s390/probes: Fix wrong opcode for cgrb fixup s390: Select ARCH_MEMORY_ORDER_TSO s390/mm: Cleanup pXXp_flush_lazy() routines s390/pci: Add function handle to RPCIT insn trace s390/pci: Use 32-bit fh outside of inline asm s390/pci: Adjust alignment in insn trace s390/sclp: Remove redundant memset after memblock_alloc_low() s390/entry: Save lowcore on invalid kernel stack s390/entry: Last breaking event vs invalid kernel stack s390/percpu: ImplemenHeiko Carstenst this_cpu_try_cmpxchg() s390/percpu: Drop unused output register from arch_this_cpu_to_op() s390/percpu: Drop unused output register from arch_this_cpu_add() s390/percpu: Use asm_inline for arch_this_cpu_add() s390/extable: Remove EX_TABLE macros and fallback extable search s390/bpf: Simplify exception table entry handling s390/sclp: Convert inline assembly to EX_TABLE_INSN ...
13 daysMerge tag 'perf-core-2026-10-18' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull perf events updates from Ingo Molnar: - Support SIMD/eGPRs/SSP register sampling in perf (Dapeng Mi, Kan Liang) - Turn amd_uncore_ctx events into a flexible array (Rosen Penev) - Finish the work related to fixing the guest PEBS path to not set unwanted PERF_GLOBAL_CTRL bits, for which urgent fixes are upstream already (Sean Christopherson) - Drop redundant counter slot searches in the AMD uncore driver (Usama Arif) - Don't WARN when the ext_regs_buf allocation fails (vineash) - Annotate x86_pmu::hybrid_pmu with __counted_by_ptr (Thorsten Blum) * tag 'perf-core-2026-10-18' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (34 commits) perf/x86: Don't WARN when the ext_regs_buf allocation fails perf/x86/amd/uncore: Free counter slot by index perf/x86/amd/uncore: Remove redundant event slot scan perf/x86/intel: Check only PMC bits in PEBS_ENABLED when detecting host PEBS usage KVM: VMX: Only tell perf to enable PEBS counters for fully enabled PMCs KVM: VMX: Drop a redundant pmu->global_ctrl check when processing pebs_enable perf/x86/intel: KVM: Handle cross-mapped PEBS PMCs entirely within KVM perf/x86: KVM: Have perf define a dedicated struct for getting guest PEBS data perf/x86/intel: Invert names of intel_ctrl_{guest,host}_mask perf/x86/intel: Annotate x86_pmu::hybrid_pmu with __counted_by_ptr perf/x86/amd/uncore: Turn amd_uncore_ctx events into a flexible array perf/x86/intel: Add sanity check for PEBS record/fragment size perf/x86: Activate back-to-back NMI detection for arch-PEBS induced NMIs perf/x86/intel: Advertise PERF_PMU_CAP_SIMD_REGS capability perf/x86/intel: Support arch-PEBS based SIMD/eGPRs sampling perf/x86: Support SSP sampling using sample_regs_* fields perf/x86: Support eGPRs sampling using sample_regs_* fields perf: Enhance perf_reg_validate() with simd_enabled argument perf/x86: Support OPMASK sampling using sample_simd_pred_reg_* fields perf/x86: Support ZMM sampling using sample_simd_vec_reg_* fields ...
13 daysMerge tag 'sched-core-2026-10-18' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull scheduler updates from Ingo Molnar: "Kconfig updates: - Simplify PREEMPT_DYNAMIC (Mark Rutland) Fair scheduler updates: - Remove redundant RUN_TO_PARITY check (Elif Topuz) - Declare augmented callbacks per field, fix rb_add_augmented_cached() descent (Yiwei Lin, Peter Zijlstra) - Restart fair hrtick after same-task repicks (Shubhang Kaushik) - Improve the scheduling latency of short slice tasks (Vincent Guittot) Deadline/RT scheduler updates: - Check start_dl_timer expiry with ktime_before() (Liang Hao) - irq_work: CPU-hotplug improvements on PREEMPT_RT (Sebastian Andrzej Siewior) Energy-aware scheduling updates: - Implement the steal_governor, introduce preferred CPUs and steal-driven vCPU backoff (Shrikanth Hegde) Multi-processor load-balancing updates: - Enable preferred SMT siblings on NVIDIA Olympus (Andrea Righi) - Randomize equally shallow idle CPU picks (Christian Loehle) - Remove redundant core_sched_seq (Hui Su) Cache-aware scheduling updates: - Avoid publishing partial LLC utilization (Jemmy Wong) NUMA-balancing updates: - Reset NUMA fault locality after scan period update (Eric Kim) Proxy execution updates: - Ongoing work to implement sleeping owner handling for proxy execution (John Stultz, Vasily Gorbik) - Preparatory steps to make sched_ext compatible with proxy execution (Andrea Righi) Scheduler infrastructure updates & fixes: - Remove the RCU wait from PSI trigger destruction (Shakeel Butt) - Avoid modifying wait-entry on failed priority registration (Hui Su) - Use the new static key API for sched_feat (Hongyan Xia) - Convert paravirt_steal to new static key APIs (Hongyan Xia) - cputime: Don't account idle time twice after dyntick-idle (Stian Halseth) Scheduler debugging updates: - Set TIF_NEED_RESCHED before calling __trace_set_need_resched() (Sechang Lim) - Fix context analysis errors in non-preferred CPU push (Shrikanth Hegde) Misc cleanups and fixes by Christian Loehle, Shubhang Kaushik, Thomas Huth and Vladimir Zapolskiy" * tag 'sched-core-2026-10-18' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (64 commits) sched: Replace nr_iowait_cpu() with a bool accessor Revert "sched/fair: Remove dead code on enqueue_task_fair()" sched/cache: Avoid publishing partial LLC utilization sched/cputime: Don't account idle time twice after dyntick-idle sched/psi: Remove the RCU wait from trigger destruction sched/eevdf: Remove redundant RUN_TO_PARITY check sched/wait: Avoid modifying entry on failed priority registration rbtree_test: Use rb_add_augmented_cached() for the cached augmented test rbtree: Update augmented data on the way down in rb_add_augmented_cached() rbtree: Declare augmented callbacks per field with RB_AUG() rbtree_test: Use rb_add() and rb_add_cached() for the basic tests smpboot: Don't park the thread if work is pending irq_work: Flush lazy work CPU down on PREEMPT_RT irq_work: Update a comment regarding CPU hotplug invocation sched/topology: Add asymmetric SMT packing override sched/fair: Honor asymmetric SMT priority in idle selection sched: Set TIF_NEED_RESCHED before calling __trace_set_need_resched() sched/core: Fix context analysis errors in non-preferred CPU push virt/steal_governor: Enable the driver virt/steal_governor: Implement steal_governor policy loop ...
13 dayss390: use get_user()/put_user() instead of the unchecked variantsLinus Torvalds
On s390 user space is a separate address space, so access_ok() has nothing to check, and get_user() and put_user() are __get_user() and __put_user() plus might_fault(). The remaining callers can use the normal accessors directly: - signal frame setup writes the back chain, the signal number and the ucontext header in process context; - the user stack walker for stack traces and perf callchains already runs under pagefault_disable(), where might_fault() returns early; - the general register set writer for ptrace runs in the tracer's process context with no locks held. This is part of getting rid of __get_user() and __put_user() entirely. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
14 daysMerge tag 'kvm-s390-next-7.4-2' of ↵Paolo Bonzini
git://git.kernel.org/pub/scm/linux/kernel/git/kvms390/linux into HEAD KVM: s390: Changes for 7.4 - rework page allocation for secure guest variable storage - selftests - documentation - replace get_zeroed_page with kzalloc - fix floating interrupt inject for corner cases - initial arm64 on s390 support This also contains the patch "arm64: Use proper include variant" as a build fix. It is also part of the arm tree.
2026-10-16sched: Replace nr_iowait_cpu() with a bool accessorChristian Loehle
The menu governor was the last consumer of the per-CPU I/O-wait count that needed its magnitude, apart from nr_iowait() summing it globally. Commit 38f83090f515 ("cpuidle: menu: Remove iowait influence") removed that use. All remaining per-CPU consumers only test for zero/nonzero. Replace nr_iowait_cpu() with bool cpu_has_iowait() and update the generic and s390 idle accounting callers. Have nr_iowait() read the counters directly so that the global total and existing accounting are preserved. Replace the stale menu comment with a description of the predicate. Also convert the remaining open-coded idle accounting checks to use the predicate, as suggested by Prateek. The conversion was done with coccinelle: @ predicate depends on patch @ expression cpu; @@ - nr_iowait_cpu(cpu) > 0 + cpu_has_iowait(cpu) @ callers depends on patch @ expression cpu; @@ - nr_iowait_cpu(cpu) + cpu_has_iowait(cpu) Signed-off-by: Christian Loehle <christian.loehle@arm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Kayra Cizmeci <kayracizmeci@gmail.com> Reviewed-by: K Prateek Nayak <kprateek.nayak@amd.com> Tested-by: K Prateek Nayak <kprateek.nayak@amd.com> Link: https://patch.msgid.link/20261016073341.575472-1-christian.loehle@arm.com
2026-10-15vdso: Remove unnecessary vdso/vsyscall.h includesThomas Weißschuh
None of these files uses anything from the header. Remove the inclusion. Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de> Signed-off-by: Thomas Gleixner <tglx@kernel.org> Link: https://patch.msgid.link/20260909-vdso-asm-generic-vsyscall-h-v1-13-63ae856cc659@linutronix.de
2026-10-15s390/vdso: Delete asm/vdso/vsyscall.h inclusionsThomas Weißschuh
The inclusions are unnecessary, remove them. Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de> Signed-off-by: Thomas Gleixner <tglx@kernel.org> Link: https://patch.msgid.link/20260909-vdso-asm-generic-vsyscall-h-v1-8-63ae856cc659@linutronix.de
2026-10-15vdso: Move the kernel-side time update helpers to a new headerThomas Weißschuh
The vdso/ header namespace is meant for symbols which are usable from vDSO userspace code. However vdso_update_begin() and vdso_update_end() are only usable from the kernel. Move them into a new header in the linux/ namespace. Also rename them to make clear that they are only for time-related data. Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de> Signed-off-by: Thomas Gleixner <tglx@kernel.org> Link: https://patch.msgid.link/20260909-vdso-asm-generic-vsyscall-h-v1-1-63ae856cc659@linutronix.de
2026-10-15s390/hwcaps: Report SAE support as hwcapHendrik Brueckner
Report SAE support as hwcap (and /proc/cpuinfo) Signed-off-by: Hendrik Brueckner <brueckner@linux.ibm.com> Reviewed-by: Steffen Eiden <seiden@linux.ibm.com> Reviewed-by: Janosch Frank <frankja@linux.ibm.com> Reviewed-by: Ilya Leoshkevich <iii@linux.ibm.com> Signed-off-by: Steffen Eiden <seiden@linux.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@linux.ibm.com>
2026-10-15s390: Introduce Start Arm Execution instructionSteffen Eiden
The Start Arm Execution (SAE) instruction is the centerpiece for executing arm64 (KVM) guests on s390. Its purpose is, similar to SIE, to enable accelerated execution of arm64 virtual machines. SAE expects the physical address of a control block as the only argument. The host is responsible to save & restore - GPRs 0-13 - access registers 0-15 - breaking event register (BEAR) - vector/floating point registers between SAE executions to guarantee host consistency. GPRs and BEAR are saved and restored in the asm functions. The other registers are handled within C code. Access registers are handled in a later patch and SVEs will be handled when they are introduced in a future series. Most arm64 registers are handled by a satellite block called save_area. Some registers, frequently used by hypervisors, are placed into the SAE control block itself. Enlighten asm/kvm_host_types.h for the new header variant. The new header is chosen instead of asm/kvm_host_s390_types.h if KVM_S390_ARM64 is defined. Co-developed-by: Andreas Grapentin <gra@linux.ibm.com> Signed-off-by: Andreas Grapentin <gra@linux.ibm.com> Co-developed-by: Nina Schoetterl-Glausch <nsg@linux.ibm.com> Signed-off-by: Nina Schoetterl-Glausch <nsg@linux.ibm.com> Reviewed-by: Ilya Leoshkevich <iii@linux.ibm.com> Signed-off-by: Steffen Eiden <seiden@linux.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@linux.ibm.com>
2026-10-15s390/uv: Rework page allocation for guest variable storage areaHeiko Carstens
Alexander Gordeev reported that the allocation of pages of the guest variable storage area via the uv_alloc_range_cb() callback of apply_to_page_range() will cause problems as soon as s390 fully supports lazy mmu mode. Problem is that uv_alloc_range_cb() allocates pages with GFP_KERNEL while preemption would be disabled. This would result in reports like this: BUG: sleeping function called from invalid context at ./include/linux/sched/mm.h:322 in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 6092, name: qemu-kvm preempt_count: 1, expected: 0 ... Call Trace: dump_stack_lvl+0xae/0x108 __might_resched+0x1de/0x2f0 prepare_alloc_pages+0x1ba/0x220 __alloc_frozen_pages_noprof+0xc6/0x390 alloc_pages_mpol+0xe6/0x220 alloc_frozen_pages_noprof+0x5c/0x80 alloc_pages_noprof+0x22/0x80 uv_alloc_range_cb+0x30/0x300 apply_to_pte_range+0x11a/0x3b0 apply_to_pmd_range+0x13a/0x250 __apply_to_page_range+0x232/0x4d0 apply_to_page_range+0x28/0x40 uv_alloc_stor_var+0x5e/0x90 kvm_s390_pv_alloc_vm+0x118/0x1e0 [kvm] kvm_s390_pv_init_vm+0x84/0x2e0 [kvm] kvm_s390_handle_pv+0x502/0xf70 [kvm] kvm_arch_vm_ioctl+0x234/0xdd0 [kvm] kvm_vm_ioctl+0x33a/0x890 [kvm] __s390x_sys_ioctl+0xfa/0x130 __do_syscall+0x1fc/0x700 system_call+0x72/0x90 Preallocate the pages and make use of vm_area_map_pages() to address this potential future bug. Reported-by: Alexander Gordeev <agordeev@linux.ibm.com> Closes: https://lore.kernel.org/all/e9449c63-b8d2-4ed9-a184-7dcab3e8dfce-agordeev@linux.ibm.com Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Acked-by: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Janosch Frank <frankja@linux.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@linux.ibm.com>
2026-10-14Merge tag 'kvmarm-fixes-7.3-2' of ↵Paolo Bonzini
git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD KVM/arm64 fixes for 7.3, round #2 - Take a reference on the last IRQ loaded into an LR to prevent it from being freed while running the guest (Marc Zyngier) - Ensure that the ITS MOVALL command only affects LPIs that were previously affined to the source redistributor (Marc Zyngier) - Fix + test for honoring the host's trap configuration when running non-protected VMs while KVM is in protected mode (Fuad Tabba) - Use the host stage-1 mapping granularity for VM_PFNMAP mappings at stage-2 (Mostafa Saleh)
2026-10-14s390/signal: Cleanup coding styleHeiko Carstens
Only whitespace, comment, indentation and other trivial changes to adopt signal.c to current coding style. No functional change. Reviewed-by: Ilya Leoshkevich <iii@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2026-10-14s390/signal: Fix incorrect return address in signal frameHeiko Carstens
exit_to_user_mode_loop() can call arch_do_signal_or_restart() multiple times when signals are pending. If the first call set up a vDSO system call restart by saving the real user return address and adjusting psw.addr so it points to the vDSO stub, a second call builds the signal frame with the wrong return address. Restore psw.addr from arch_data, and set the return code to -EINTR before building the signal frame. This requires restart_block.arch_data to be properly initialized for all tasks. Move the initialization in copy_thread() in front of the kernel thread check, so that it also covers kernel threads and their children (PID 1, usermode helpers). Only PID 0 is left uninitialized, since it never returns to user space. Fixes: df29a7440c4b ("s390/signal: switch to using vdso for sigreturn and syscall restart") Cc: stable@vger.kernel.org Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2026-10-13s390/entry: Save lowcore on invalid kernel stackHeiko Carstens
In case of an invalid kernel stack copy the current CPU's lowcore to stack_invalid_lowcore, so it is available to debug tools after a crash. The copy is helpful since the lowcore is modified e.g., when printing messages before a dump is taken. Keep it as unmodified as possible and as close to the event that caused register corruption. Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2026-10-13s390/entry: Last breaking event vs invalid kernel stackHeiko Carstens
In case an invalid kernel stack is detected the last breaking event address is copied to the orig_gpr2 member of the generated pt_regs structure. Correct location would be last_break. Fix this. This adds help information to the printed messages: Before: Kernel stack pointer invalid ... Last Breaking-Event-Address: [<0000000000000000>] 0x0 After: Kernel stack pointer invalid ... Last Breaking-Event-Address: [<000001b802c1ae1c>] proc_reg_write+0x5c/0xd0 Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2026-10-13s390/traps: Convert inline assembly to EX_TABLE_INSNHeiko Carstens
Convert the monitor call exception table entry to use EX_TABLE_INSN. Reviewed-by: Ilya Leoshkevich <iii@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2026-10-13s390/ipl: Convert inline assembly to EX_TABLE_INSNHeiko Carstens
Convert the diag308 exception table entry to use EX_TABLE_INSN. With EX_TABLE_INSN entries always point to the faulting instruction, so nopr padding is no longer needed and removed. Reviewed-by: Ilya Leoshkevich <iii@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2026-10-13s390/cert_store: Convert inline assembly to EX_TABLE_INSNHeiko Carstens
Convert the diag320 exception table entry to use EX_TABLE_INSN. With EX_TABLE_INSN entries always point to the faulting instruction, so nopr padding is no longer needed and removed. Reviewed-by: Ilya Leoshkevich <iii@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2026-10-13s390/diag: Convert inline assembly to EX_TABLE_INSNHeiko Carstens
Convert all diag exception table entries to use EX_TABLE_INSN. With EX_TABLE_INSN entries always point to the faulting instruction, so duplicate entries and nopr padding are no longer needed and removed. Reviewed-by: Ilya Leoshkevich <iii@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2026-10-13s390/diag: Convert amode31 exception tables to EX_TABLE_INSNHeiko Carstens
Convert all amode31 exception table entries to use EX_TABLE_INSN. With EX_TABLE_INSN entries always point to the faulting instruction, so named labels are replaced with numeric labels. Reviewed-by: Ilya Leoshkevich <iii@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2026-10-13s390/dis: Improve show_code() outputHeiko Carstens
Replace the '>' and '*' instruction markers with explicit 'PSW >' and 'PGM >' markers which identify both the PSW address and the faulting instruction. Previously, '>' marked the PSW address, while '*' marked the preceding instruction as a guess for the faulting instruction for suppressing exceptions: Krnl Code: 000003ff8dc7bff8: e310f0080004 lg %r1,8(%r15) *000003ff8dc7bffe: e3a0e0000004 lg %r10,0(%r14) >000003ff8dc7c004: a7280000 lhi %r2,0 000003ff8dc7c008: eb9ff0900024 stmg %r9,%r15,144(%r15) Now 'PGM >' explicitly marks the faulting instruction without guessing and 'PSW >' marks the PSW address: Krnl Code: 000003ff8dc7bff8: e310f0080004 lg %r1,8(%r15) PGM >000003ff8dc7bffe: e3a0e0000004 lg %r10,0(%r14) PSW >000003ff8dc7c004: a7280000 lhi %r2,0 000003ff8dc7c008: eb9ff0900024 stmg %r9,%r15,144(%r15) For nullifying exceptions where both addresses are the same, 'PGM+PSW >' is printed instead: Krnl Code: 000003ff8dc7bff8: e310f0080004 lg %r1,8(%r15) PGM+PSW >000003ff8dc7bffe: e3a0e0000004 lg %r10,0(%r14) 000003ff8dc7c004: a7280000 lhi %r2,0 000003ff8dc7c008: eb9ff0900024 stmg %r9,%r15,144(%r15) show_code() may also be called in other contexts where pt_regs does not originate from a program check (e.g. system calls). Introduce and set PIF_PGM_CHECK to indicate when in program check context, and print the PGM marker only in such a context. Note that corner cases are not taken into account. Like before kprobes is not considered, which means that the disassembly may contain unexpected instructions, or that disassembly and/or instruction length count as well as interruption do not match. Reviewed-by: Ilya Leoshkevich <iii@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2026-10-13s390/traps: Handle nullifying program checks in get_trap_ip()Heiko Carstens
get_trap_ip() always rewinds the PSW address by the instruction length from the interruption code. For nullifying program checks the PSW already points at the faulting instruction, so rewinding is wrong. Add a nullified[] bitmap and return the unchanged PSW address for nullifying cases, or if PIF_PSW_ADDR_ADJUSTED is set. No functional change for existing callers, which only deal with suppressing, terminating, or completing program checks. Reviewed-by: Ilya Leoshkevich <iii@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2026-10-13s390/bug: Indicate modified PSW in disassemblyHeiko Carstens
With [1] the PSW address is set to the return address of the calling __WARN_trap() function in order to provide a more useful disassembly of the caller rather than the helper itself. However, since regs->psw.addr is modified, regs->int_code has nothing to do with the exception. In order to make that more obvious change the disassembler output. Introduce a new PIF_WARN_TRAP_SKIPPED pt_regs flag and set it whenever __WARN_trap() is skipped. In the disassembler output print a "WARN RET" prefix to make it obvious that the PSW points to the return address of the warning trap function. Also do not print the interruption code and instruction length code for this case, since they have nothing to do with the modified PSW. Example output: Krnl Code: 000003ffe185bc1c: e3f0ff98ff71 lay %r15,-104(%r15) 000003ffe185bc22: e3e0f0980024 stg %r14,152(%r15) 000003ffe185bc28: c0e5ff45ed94 brasl %r14,000003ffe0119750 WARN RET >000003ffe185bc2e: c0e5ffa052b9 brasl %r14,000003ffe0c661a0 000003ffe185bc34: c020fffe86d6 larl %r2,000003ffe182c9e0 000003ffe185bc3a: e548f0a80006 mvghi 168(%r15),6 000003ffe185bc40: e548f0a00005 mvghi 160(%r15),5 000003ffe185bc46: a7690004 lghi %r6,4 [1] 79996065cfa2 ("s390/bug: Skip __WARN_trap() in call traces") Reviewed-by: Ilya Leoshkevich <iii@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2026-10-13s390: Clear pt_regs flags fieldHeiko Carstens
Clear the pt_regs flags field in the early program check handler as well as in the stack_invalid handler. Without this the pt_regs flags field will have random values, depending on previous stack contents. This matters currently for bug reporting and disassembly, where flags like PIF_PSW_ADDR_ADJUSTED may then be incorrectly set, which could lead to a partially incorrect disassembly or wrong code markers. Reviewed-by: Ilya Leoshkevich <iii@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2026-10-13s390/early: Fix early warning handlingHeiko Carstens
When adding support for __WARN_printf() the early program check handler was not taken into account. Add the missing support to the early program check handler. This avoids that the kernel crashes instead of printing a warning. Fixes: 04dabb4261c3 ("s390/bug: Implement __WARN_printf()") Fixes: 79996065cfa2 ("s390/bug: Skip __WARN_trap() in call traces") Reviewed-by: Ilya Leoshkevich <iii@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2026-10-13s390/kprobes: Prevent kprobes on instructions with exception table entryHeiko Carstens
The mvcos exception handler ex_handler_ua_mvcos() decodes the faulting instruction, assuming it is an mvcos instruction. In case the instruction is kprobed the decoded instruction is a breakpoint instruction instead, which leads to incorrect instruction decoding and potential register corruption. Fix this by simply preventing to set a kprobe on such instructions, similar like arm64 is doing it. Fixes: c488f5187a24 ("s390/uaccess: Shorten raw_copy_from_user() / raw_copy_to_user() inline assemblies") Cc: stable@vger.kernel.org Reviewed-by: Ilya Leoshkevich <iii@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2026-10-13s390/uprobes: Fix off-by-one bug in emulated PER handlingHeiko Carstens
The uprobes code emulates some instructions, and with that also PER storage-alteration handling, in case a debugger is attached. The PER storage-alteration handling contains an off-by-one bug, which may lead to PER traps which should not happen. Adjust the comparison in sim_stor_event() to fix that. Fixes: 8d1a2427d8fc ("s390/uprobes: fix user space PER events") Reviewed-by: Sven Schnelle <svens@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2026-10-13s390/ptrace: Preserve ILC when updating system call numberHeiko Carstens
When an attached debugger changes gpr2 via PTRACE_POKEUSR while the traced process has PIF_SYSCALL set, the int_code in pt_regs is also updated. In case of an svc it contains the instruction length code (ILC), as well as the system call number. The ptrace code sets the ILC unconditionally to a value which matches the svc instruction. However the svc instruction also may have been executed via the execute or execute relative long instruction, which have a different length. Therefore preserve the ILC and only change the system call number using syscall_set_nr(). This makes sure that in case of a PSW rewind the instruction address points to the correct instruction. Fixes: 56e62a737028 ("s390: convert to generic entry") Reviewed-by: Sven Schnelle <svens@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2026-10-13Merge branch 'tip/sched/urgent'Peter Zijlstra
Pickup dependencies; notably the RB-tree fix. Signed-off-by: Peter Zijlstra <peterz@infradead.org>
2026-10-09Merge tag 'kvm-s390-next-7.4-1' of ↵Paolo Bonzini
git://git.kernel.org/pub/scm/linux/kernel/git/kvms390/linux into HEAD KVM/vfio: Use file-based reference counting for KVM This series switches the KVM-VFIO interface and external consumers over to standard file-based reference counting, eliminating all external KVM symbol exports. Currently, VFIO integrates with KVM by looking up kvm_get_kvm_safe() and kvm_put_kvm() dynamically using symbol_get(), manually tracking module reference counts and storing a put_kvm function pointer in struct vfio_device. In the ARM64-on-s390 architecture, a second concurrent KVM module (kvm-arm64) is introduced alongside native KVM to host hardware-accelerated ARM64 guests. Having exported global symbols (like kvm_get_kvm/kvm_put_kvm) creates symbol conflicts and prevents clean coexistence of two KVM modules. Additionally, the file based counting simplifies the code and reuses the existing fs refcounting. Instead of passing raw KVM pointers and managing module symbols manually, the interface now passes the underlying VM file descriptor throughout VFIO and associated architecture subsystems. To safely extract the KVM instance from a file, an architecture-namespaced helper mechanism is introduced that verifies the file belongs to the expected KVM implementation before accessing its internal state. A back-pointer from the KVM instance to its associated file is maintained across its lifecycle so subsystems can safely acquire file references on demand. Finally, with VFIO, architecture page tracking, and device hooks converted to use file references, the remaining KVM reference- counting exports are restricted strictly to internal KVM modules.
2026-10-09s390/vtime: Remove vtimer infrastructureHeiko Carstens
The only user is gone - remove the vtimer infrastructure. Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2026-10-09s390/cpum_cf: Honor hwctr session cpu mask during hotplugSumanth Korikkar
cfset_online_cpu() and cfset_offline_cpu() cpu hotplug callbacks start and stop counter sets for every active hwctr session without checking the session cpu mask, and dynamically modify that mask on each hotplug event. For example, assume cpu0 and cpu1 are online and cpu2 is offline. Start an hwctr session restricted to cpu0 and cpu1, and then bring cpu2 online: lshwc -l 9999 -i 5 0-1:b chcpu -e 2 Although cpu2 is not part of the requested mask, cfset_online_cpu() starts the counter sets on cpu2 and adds it to the session mask. cpu2 can then appear in lshwc output (s390-tools) and is handled as part of the session until it is stopped. Keep the userspace provided cpu mask unchanged and update counter sets only when the hotplugged cpu belongs to that mask. For all cpu requests, lshwc should supply the possible cpu mask so that cpus coming online later remain part of the session. Note: A corresponding lshwc (s390-tools) change is needed to supply the possible cpu mask for allcpu sessions, ensuring that cpus coming online later remain part of the session. Without it, newly online cpus would be silently excluded from an active session. Since this userspace change is not yet available, the patch is not suitable for stable kernels and intentionally omits a Fixes: tag. The prerequisite bug fix is in "s390/cpum_cf: Check session mask before cpu offline". Reported-by: Christian Borntraeger <borntraeger@linux.ibm.com> Signed-off-by: Sumanth Korikkar <sumanthk@linux.ibm.com> Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2026-10-09s390/cpum_cf: Check session mask before cpu offlineSumanth Korikkar
cfset_offline_cpu() stops counter sets for every active session without checking whether the outgoing cpu belongs to the session mask. For example, run an hwctr session on cpu0 and a cpu bound perf event on cpu1: lshwc -l 9999 -i 5 0:b perf stat -C 1 -e cpum_cf/CPU_CYCLES/ sleep 120 chcpu -d 1 chcpu -e 1 Although the hwctr session does not include cpu1, cfset_offline_cpu() decrements its counter set reference count. The subsequent perf teardown decrements it again, causing it to underflow. The perf event keeps the percpu state alive across hotplug. When cpu1 comes online, the hwctr session is started there and the reference count moves from -1 to 0. Stopping the hwctr session then decrements it to -1 again, so the zero triggered counter set disable path is skipped. Check the session mask before stopping counter sets on the outgoing cpu. This prevents the unmatched decrement and the resulting reference count underflow. Fixes: a029a4eab39e ("s390/cpumf: Allow concurrent access for CPU Measurement Counter Facility") Reported-by: Christian Borntraeger <borntraeger@linux.ibm.com> Cc: stable@vger.kernel.org # v5.14+ Signed-off-by: Sumanth Korikkar <sumanthk@linux.ibm.com> Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2026-10-09s390/dis: Mark non-NUL-terminated character arrays with __nonstringHeiko Carstens
With [1] the generated string initializers were changed to use an array instead of a non-NUL-terminated string. The reason was that GCC 15 warns about string initializers that truncate the NUL terminator with -Wunterminated-string-initialization. The better solution is to use the __nonstring annotation, which exists to deal exactly with this problem. Therefore use it and basically revert [1] in order to generate more readable initializers: Before: [LONG_INSN_ALGHSIK] = { 'a', 'l', 'g', 'h', 's', 'i', 'k', }, After: [LONG_INSN_ALGHSIK] = "alghsik", [1] commit 7cbae7ea3de5 ("s390/tools: Use array instead of string initializer") Reviewed-by: Jens Remus <jremus@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2026-10-06s390: implement arch_do_panicMete Durlu
Implement s390 specific arch_do_panic() instead of using s390 specific ifdef sections in vpanic() code. disabled_wait() is now called after "end Kernel panic" marker. No functional changes. Link: https://lore.kernel.org/20260831-arch_do_panic-v6-2-a1e170a9e7fd@linux.ibm.com Signed-off-by: Mete Durlu <meted@linux.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Heiko Carstens <hca@linux.ibm.com> Reviewed-by: Bradley Morgan <include@grrlz.net> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Andreas Larsson <andreas@gaisler.com> Cc: Christian Borntraeger <borntraeger@linux.ibm.com> Cc: David S. Miller <davem@davemloft.net> Cc: Petr Mladek <pmladek@suse.com> Cc: Sven Schnelle <svens@linux.ibm.com> Cc: Vasily Gorbik <gor@linux.ibm.com>
2026-10-02Merge tag 'random-7.3-rc6-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/crng/random Pull random number generator fixes from Jason Donenfeld: - VMGENID memory needs to be mapped with the decrypted tag, so that SEV-SNP machines can boot - A fix for an initialization race in VMGENID, followed by a cleanup - Trivial kernel doc cleanups in siphash and random.c - A fix for a new compilation failure with recent clang on PPC and RISC-V, due to generating an out-of-line memset in the vDSO * tag 'random-7.3-rc6-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/crng/random: random: vDSO: avoid call to memset() when zeroing reserved parameter random: fix vgetrandom_opaque_params kernel-doc random: vDSO: fix repeated word 'to' in comment siphash: clean up kernel-doc comments virt: vmgenid: move to using dev_set/get_drvdata virt: vmgenid: set driver_data before registering notification handlers virt: vmgenid: remap memory as decrypted
2026-10-02random: vDSO: avoid call to memset() when zeroing reserved parameterNathan Chancellor
After a recent change in LLVM [1], builds with the random vDSO implementation, such as PowerPC and RISC-V, fail when checking the vDSO: arch/powerpc/kernel/vdso/vdso32.so.dbg: dynamic relocations are not supported arch/riscv/kernel/vdso/vdso.so.dbg: dynamic relocations are not supported memset() is now generated when zeroing params->reserved for some builds because LLVM has an optimization (now run in more instances) that can recognize at compile time when it is assigning a static value to a contiguous area of memory and turn that into a call to memset(). Both clang and GCC assume memset() is always available [2]. Clang has an internal fiddly hook, -max-store-memset, which we can set to a high number, to disable generating out of line memset calls [3]. Similarly, GCC has -finline-stringops=memset to do the same [4], should this issue ever hit future version of GCC. While these options wouldn't make sense for normal kernel code, it is fine for the extremely limited and intentionally compact vDSO code. Link: https://github.com/llvm/llvm-project/commit/90cebef1411617fc3eedd359bdf00cb44b1c2439 [1] Link: https://gcc.gnu.org/onlinedocs/gcc-16.2.0/gcc/Standards.html#index-ffreestanding [2] Link: https://github.com/llvm/llvm-project/commit/b28eeb28bea39148738dc375e8a97072a1907e64 [3] Link: https://gcc.gnu.org/onlinedocs/gcc/Optimize-Options.html#index-finline-stringops [4] Closes: https://github.com/ClangBuiltLinux/linux/issues/2183 Cc: stable@vger.kernel.org # v6.12+ Signed-off-by: Nathan Chancellor <nathan@kernel.org> Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
2026-09-30s390/percpu: Rework to simplify percpu_entry() and percpu_exit()Heiko Carstens
The percpu code section functionality uses a rather complex method to figure out if the register, which contains the address of the current cpu's percpu variable, needs to be adjusted. If an interrupt happens within a percpu code section (indicated by a lowcore field), the instruction at the interrupted location is checked. If it is not a specific AG instruction, the register needs to be updated. This mechanism needs to take kprobes into account, and enforces a specific instruction ordering. Mark Rutland provided a different solution for arm64 [1] which comes without such limitations, but requires to use one more instruction, and two more registers. Given that this simplifies percpu_entry() and percpu_exit() it seems to be worth to go that route. Change s390 to implement a similar approach. This requires to encode three register numbers into the "percpu_register" field, which is used to indicate if a percpu code section is executed. The used mviy instruction can write only one byte, which allows to encode only two register numbers. Use a register pair for the inline assemblies, and only encode the even register number of the register pair to work around this. The generated code changes like this for e.g. a simple this_cpu_inc(): Old: c0 20 00 00 00 00 larl %r2,c6 <foo+0x6> <-- load address of percpu var b9 04 00 32 lgr %r3,%r2 <-- pointless copy of address eb 03 03 c0 00 52 mviy 960,3 <-- start of percpu code section - gpr 3 contains percpu var address e3 30 03 b8 00 08 ag %r3,952 <-- add percpu offset eb 01 30 00 00 7a agsi 0(%r3),1 <-- atomic inc eb 00 03 c0 00 52 mviy 960,0 <-- end of percpu code section New: c0 10 00 00 00 00 larl %r1,c6 <foo+0x6> <-- load address of percpu var eb 21 03 c0 00 52 mviy 960,33 <-- start of percpu code section 33 == 0x21: - gpr 1 contains percpu var address - gpr 2 used for percpu offset - gpr 2+1 == 3 used for current cpu's percpu var address e3 20 03 b8 00 04 lg %r2,952 <-- load percpu offset 41 32 10 00 la %r3,0(%r2,%r1) <-- generate current cpu's percpu var address eb 01 30 00 00 7a agsi 0(%r3),1 <-- atomic inc eb 00 03 c0 00 52 mviy 960,0 <-- end of percpu code section In the above "new" code example 33 (0x21) is used as indicator value to mark that a percpu code section is executed. This value implies that registers 2 and 3 will (only) hold the percpu offset and the current cpu's percpu var address. Those registers will be updated by percpu_exit() if the process was migrated to a different cpu to contain the percpu offset and percpu var address of the new cpu. Note that because of the pointless lgr instruction in the "old" code example the two code sequences have identical size, and it looks like only one more register is used. However this is because of suboptimal gcc code generation. [1] https://lore.kernel.org/all/20260908151741.394589-1-mark.rutland@arm.com/ Acked-by: Alexander Gordeev <agordeev@linux.ibm.com> Tested-by: Mete Durlu <meted@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2026-09-28sched/cputime: Add kcpustat_field_total helperShrikanth Hegde
Provide a new helper function which sums up a given type of cpustat over a specified cpumask. This allows the caller's code to be simpler and avoids duplication. For example, subsequent patch in the steal governor use this exact same pattern when calculating steal time. Number of cpus can be derived from cpumask_weight() where necessary. Suggested-by: Yury Norov <yury.norov@gmail.com> Signed-off-by: Shrikanth Hegde <sshegde@linux.ibm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Yury Norov <ynorov@nvidia.com> Reviewed-by: Mete Durlu <meted@linux.ibm.com> Acked-by: Frederic Weisbecker <frederic@kernel.org> Link: https://patch.msgid.link/20260928053728.797539-2-sshegde@linux.ibm.com
2026-09-26Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds
Pull kvm fixes from Paolo Bonzini: "Arm: - Invalidate the ITS translation cache when the guest changes the base address of the ITS tables (Fuad Tabba) - Skip saving ITS devices with device IDs that are out-of-bounds rather than failing the entire ITS save ioctl (Fuad Tabba) - Close race between VM teardown and invalidations of nested MMUs when handling MMU operations that are allowed to block (Lorenzo Stoakes) - Various fixes for the handling of the host's untrusted SVE configuration in pKVM (Fuad Tabba) - Make sure that empty SMCCC ranges based at 0 are rejected by the kvm_smccc_set_filter() (Karl Mehltretter) - Revoke the host mapping for pKVM's private stack pages, along with a new sanity check that all mappings in the hyp's private VA range have been correctly marked as hyp-owned (Fuad Tabba) - Lifetime fixes for the array of shadow stage-2 MMUs, ensuring that concurrent vCPU initialization cannot relocate in-use MMUs. Defer the freeing of shadow stage-2 MMUs to the point that no other users (e.g. MMU notifier) could reference them (Marc Zyngier) - Drop useless WARN when rejecting an unsupported ioctl for pKVM (Fuad Tabba) - Fix the steal_time selftest to install correctly-sized mappings for non-4K hosts (Sebastian Ott) - Correct mapping of fine-grained trap for GCSPOPX instruction (Mark Brown) - Fix KVM_BUG_ON() due to missing handling of DBGBXVR<n> from 32-bit guests (Karl Mehltretter) RISC-V: - Synchronize hrtimer during VCPU teardown - Fix the conversion between vsip and hvip values - Serialize IMSIC attributes with vCPU migration - Release unused page after MMU invalidation - Propagate interrupted G-stage faults to KVM user-space as EINTR - Fix nested acceleration hfence entry update order - Fix sdata leak and stale snapshot_addr in snapshot_set_shmem - Preserve firmware counter value across PMU counter stop/start - Report PMU snapshot write failure to the guest - Fix perf-backed counter accounting across PMU stop and read - Correctly propagate error of a hart status SBI call s390: - Ensure that accesses through kvm_arch_set_irq_inatomic mark as dirty the pages that contain indicator and summary bits - Fix compile warning for kvm_s390_update_cmma_dirty() - Fix incorrect propagation of ENOENT from _gaccess_shadow_fault() to userspace - Move s390_kvm_mmu_commit_memory_region() into s390_kvm_mmu_prepare_memory_region() so that it can fail instead of WARN - Add missing srcu in kvm_s390_set_irq_state() - Fix potential races in storage functions - Fix race in _destroy_pages_crste() - Fix issues in the handling of KVM interrupt and page resources, when a queue that is assigned to a mediated device (mdev) is removed from the host's AP configuration - Fix loop condition in uv_find_secrets - Prevent potential out-of-bounds read x86: - Fix a brown paper bag bug where KVM would incorrectly treat Intel PMU MSRs as valid on AMD - Fix a regression in the hardware disable selftest where it checked the wrong macro when detecting glibc support (breaks at least musl) - Never clear KVM_REQ_VM_DEAD so that dead VMs stay dead, which is especially important for KVM_BUG_ON() flows, which often guard more dangerous bugs - Re-pend GET_NESTED_STATE_PAGES if getting the pages fails, to fix a bug where KVM would let userspace run a broken setup with stale vmcs12 pages - Fix a class of bugs where KVM would fail to fill kvm_run exit fields if getting nested pages failed - Treat reserved entries in the memory attributes xarray as "no attributes", to fix false positives when checking for mixed attributes - Fix memcg accounting for the memory attributes xarray (the xarray library subtly requires the xarray to be configured for accounting upfront; the gfp flags taken at runtime are used only rarely) - Don't pre-reserve xarray entries when storing empty attributes, as storing NULL must not require memory allocation (KVM and other subsystems heavily rely on this behavior) - Fix a memory leak and a cache maintenance issue related to doing intra-host migration on an SEV guest" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (54 commits) KVM: SEV: Do cache maintenance on the source VM during intra-host migration KVM: SEV: Free have_run_cpus during VM destruction even if VM is no longer SEV KVM: Don't pre-reserve xarray entries when storing empty/NULL attributes KVM: Ensure memory attributes xarray nodes are accounted to the caller's memcg KVM: Don't treat reserved xarray entries as having memory attributes KVM: x86: Fill kvm_run exit fields in common get_nested_state_pages() error paths KVM: x86: Re-pend GET_NESTED_STATE_PAGES if getting said pages fails KVM: arm64: Fix AArch32 DBGBXVR<n> handling KVM: arm64: Fix FGT mapping for HFGITR_EL2.nGCSEPP KVM: selftests: fix steal_time for arm64 with host page size > 4K KVM: arm64: Don't WARN on an unknown VM ioctl in protected mode KVM: arm64: nv: Delay freeing of shadow S2 structures until VM destruction KVM: arm64: nv: Fix life cycle of the nested_mmus array KVM: arm64: Check every private mapping is hyp-owned at pKVM init KVM: arm64: Move the private VA allocation cursor to __io_map_next KVM: arm64: Match hyp text by physical address in fix_host_ownership() KVM: arm64: Transfer the hyp stack pages out of the host stage-2 KVM: arm64: selftests: Test empty SMCCC filter range at base 0 KVM: arm64: Return -EINVAL for an empty SMCCC filter range at base 0 KVM: arm64: Derive GUEST_HAS_SVE from the SVE feature bit at EL2 ...
2026-09-23Merge branch 'perf/urgent' into perf/core, to resolve conflictIngo Molnar
Conflicts: include/linux/perf_event.h Signed-off-by: Ingo Molnar <mingo@kernel.org>
2026-09-22s390/debug: Fix NULL pointer dereference in debug_info_copy()Mikhail Zaslonko
When debug_register_static() fails, it clears areas, active_pages and active_entries but leaves the area bounds unchanged. Copying such an area, either by opening its view file or via debug_dump(), makes debug_info_copy() dereference the NULL pointers. Skip the copy loop when the source has no areas. Closes: https://lore.kernel.org/r/20260903132123.12F271F00A3F@smtp.kernel.org Fixes: d72541f94512 ("s390/debug: add early tracing support") Signed-off-by: Mikhail Zaslonko <zaslonko@linux.ibm.com> Reviewed-by: Peter Oberparleiter <oberpar@linux.ibm.com> Acked-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2026-09-22s390/debug: Do not register views for failed static debug areasMikhail Zaslonko
__REGISTER_STATIC_DEBUG_INFO() calls debug_register_view() unconditionally, even when debug_register_static() has failed. In that case _debug_register() was never reached and id->debugfs_root_entry is still NULL, so debugfs_create_file() places the view file in the debugfs root directory. For sclp_err this leaves a /sys/kernel/debug/hex_ascii file with nothing to indicate which debug log it belongs to. debug_register_static() is not exported and the macro is its only caller, so let it return an error code and skip the view registration when it fails. No debugfs files are created for such an area then. Reproduce by booting with s390dbf=sclp_err::100000000. The sclp_err registration fails, no s390dbf/sclp_err/ directory is created, and a hex_ascii file appears in the debugfs root instead. Fixes: d72541f94512 ("s390/debug: add early tracing support") Signed-off-by: Mikhail Zaslonko <zaslonko@linux.ibm.com> Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2026-09-22s390/debug: Reject NULL debug info in debug_dump()Mikhail Zaslonko
debug_dump() passes id on to debug_info_copy(), which dereferences in->name unchecked. debug_unregister(), debug_set_size() and debug_register_view() guard against a NULL id but debug_dump() does not. Nothing reaches this today, but add the check for consistency. Reported-by: Sashiko <sashiko-bot@kernel.org> Closes: https://lore.kernel.org/all/20260910110147.96E851F000FF@smtp.kernel.org/ Signed-off-by: Mikhail Zaslonko <zaslonko@linux.ibm.com> Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>