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2026-02-21compiler_types: Disable __builtin_counted_by_ref for ClangKees Cook
Unfortunately, there is a corner case of __builtin_counted_by_ref() usage that crashes[1] Clang since support was introduced in Clang 19. Disable it prior to Clang 22. Found while tested kmalloc_obj treewide refactoring (via kmalloc_flex() usage). Link: https://github.com/llvm/llvm-project/issues/182575 [1] Signed-off-by: Kees Cook <kees@kernel.org>
2026-02-12Merge tag 'mm-nonmm-stable-2026-02-12-10-48' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Pull non-MM updates from Andrew Morton: - "ocfs2: give ocfs2 the ability to reclaim suballocator free bg" saves disk space by teaching ocfs2 to reclaim suballocator block group space (Heming Zhao) - "Add ARRAY_END(), and use it to fix off-by-one bugs" adds the ARRAY_END() macro and uses it in various places (Alejandro Colomar) - "vmcoreinfo: support VMCOREINFO_BYTES larger than PAGE_SIZE" makes the vmcore code future-safe, if VMCOREINFO_BYTES ever exceeds the page size (Pnina Feder) - "kallsyms: Prevent invalid access when showing module buildid" cleans up kallsyms code related to module buildid and fixes an invalid access crash when printing backtraces (Petr Mladek) - "Address page fault in ima_restore_measurement_list()" fixes a kexec-related crash that can occur when booting the second-stage kernel on x86 (Harshit Mogalapalli) - "kho: ABI headers and Documentation updates" updates the kexec handover ABI documentation (Mike Rapoport) - "Align atomic storage" adds the __aligned attribute to atomic_t and atomic64_t definitions to get natural alignment of both types on csky, m68k, microblaze, nios2, openrisc and sh (Finn Thain) - "kho: clean up page initialization logic" simplifies the page initialization logic in kho_restore_page() (Pratyush Yadav) - "Unload linux/kernel.h" moves several things out of kernel.h and into more appropriate places (Yury Norov) - "don't abuse task_struct.group_leader" removes the usage of ->group_leader when it is "obviously unnecessary" (Oleg Nesterov) - "list private v2 & luo flb" adds some infrastructure improvements to the live update orchestrator (Pasha Tatashin) * tag 'mm-nonmm-stable-2026-02-12-10-48' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (107 commits) watchdog/hardlockup: simplify perf event probe and remove per-cpu dependency procfs: fix missing RCU protection when reading real_parent in do_task_stat() watchdog/softlockup: fix sample ring index wrap in need_counting_irqs() kcsan, compiler_types: avoid duplicate type issues in BPF Type Format kho: fix doc for kho_restore_pages() tests/liveupdate: add in-kernel liveupdate test liveupdate: luo_flb: introduce File-Lifecycle-Bound global state liveupdate: luo_file: Use private list list: add kunit test for private list primitives list: add primitives for private list manipulations delayacct: fix uapi timespec64 definition panic: add panic_force_cpu= parameter to redirect panic to a specific CPU netclassid: use thread_group_leader(p) in update_classid_task() RDMA/umem: don't abuse current->group_leader drm/pan*: don't abuse current->group_leader drm/amd: kill the outdated "Only the pthreads threading model is supported" checks drm/amdgpu: don't abuse current->group_leader android/binder: use same_thread_group(proc->tsk, current) in binder_mmap() android/binder: don't abuse current->group_leader kho: skip memoryless NUMA nodes when reserving scratch areas ...
2026-02-10Merge tag 'timers-vdso-2026-02-09' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull VDSO updates from Thomas Gleixner: - Provide the missing 64-bit variant of clock_getres() This allows the extension of CONFIG_COMPAT_32BIT_TIME to the vDSO and finally the removal of 32-bit time types from the kernel and UAPI. - Remove the useless and broken getcpu_cache from the VDSO The intention was to provide a trivial way to retrieve the CPU number from the VDSO, but as the VDSO data is per process there is no way to make it work. - Switch get/put_unaligned() from packed struct to memcpy() The packed struct violates strict aliasing rules which requires to pass -fno-strict-aliasing to the compiler. As this are scalar values __builtin_memcpy() turns them into simple loads and stores - Use __typeof_unqual__() for __unqual_scalar_typeof() The get/put_unaligned() changes triggered a new sparse warning when __beNN types are used with get/put_unaligned() as sparse builds add a special 'bitwise' attribute to them which prevents sparse to evaluate the Generic in __unqual_scalar_typeof(). Newer sparse versions support __typeof_unqual__() which avoids the problem, but requires a recent sparse install. So this adds a sanity check to sparse builds, which validates that sparse is available and capable of handling it. - Force inline __cvdso_clock_getres_common() Compilers sometimes un-inline agressively, which results in function call overhead and problems with automatic stack variable initialization. Interestingly enough the force inlining results in smaller code than the un-inlined variant produced by GCC when optimizing for size. * tag 'timers-vdso-2026-02-09' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: vdso/gettimeofday: Force inlining of __cvdso_clock_getres_common() x86/percpu: Make CONFIG_USE_X86_SEG_SUPPORT work with sparse compiler: Use __typeof_unqual__() for __unqual_scalar_typeof() powerpc/vdso: Provide clock_getres_time64() tools headers: Remove unneeded ignoring of warnings in unaligned.h tools headers: Update the linux/unaligned.h copy with the kernel sources vdso: Switch get/put_unaligned() from packed struct to memcpy() parisc: Inline a type punning version of get_unaligned_le32() vdso: Remove struct getcpu_cache MIPS: vdso: Provide getres_time64() for 32-bit ABIs arm64: vdso32: Provide clock_getres_time64() ARM: VDSO: Provide clock_getres_time64() ARM: VDSO: Patch out __vdso_clock_getres() if unavailable x86/vdso: Provide clock_getres_time64() for x86-32 selftests: vDSO: vdso_test_abi: Add test for clock_getres_time64() selftests: vDSO: vdso_test_abi: Use UAPI system call numbers selftests: vDSO: vdso_config: Add configurations for clock_getres_time64() vdso: Add prototype for __vdso_clock_getres_time64()
2026-02-10Merge tag 'sched-core-2026-02-09' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull scheduler updates from Ingo Molnar: "Scheduler Kconfig space updates: - Further consolidate configurable preemption modes (Peter Zijlstra) Reduce the number of architectures that are allowed to offer PREEMPT_NONE and PREEMPT_VOLUNTARY, reducing the number of preemption models from four to just two: 'full' and 'lazy' on up-to-date architectures (arm64, loongarch, powerpc, riscv, s390, x86). None and voluntary are only available as legacy features on platforms that don't implement lazy preemption yet, or which don't even support preemption. The goal is to eventually remove cond_resched() and voluntary preemption altogether. RSEQ based 'scheduler time slice extension' support (Thomas Gleixner and Peter Zijlstra): This allows a thread to request a time slice extension when it enters a critical section to avoid contention on a resource when the thread is scheduled out inside of the critical section. - Add fields and constants for time slice extension - Provide static branch for time slice extensions - Add statistics for time slice extensions - Add prctl() to enable time slice extensions - Implement sys_rseq_slice_yield() - Implement syscall entry work for time slice extensions - Implement time slice extension enforcement timer - Reset slice extension when scheduled - Implement rseq_grant_slice_extension() - entry: Hook up rseq time slice extension - selftests: Implement time slice extension test - Allow registering RSEQ with slice extension - Move slice_ext_nsec to debugfs - Lower default slice extension - selftests/rseq: Add rseq slice histogram script Scheduler performance/scalability improvements: - Update rq->avg_idle when a task is moved to an idle CPU, which improves the scalability of various workloads (Shubhang Kaushik) - Reorder fields in 'struct rq' for better caching (Blake Jones) - Fair scheduler SMP NOHZ balancing code speedups (Shrikanth Hegde): - Move checking for nohz cpus after time check - Change likelyhood of nohz.nr_cpus - Remove nohz.nr_cpus and use weight of cpumask instead - Avoid false sharing for sched_clock_irqtime (Wangyang Guo) - Cleanups (Yury Norov): - Drop useless cpumask_empty() in find_energy_efficient_cpu() - Simplify task_numa_find_cpu() - Use cpumask_weight_and() in sched_balance_find_dst_group() DL scheduler updates: - Add a deadline server for sched_ext tasks (by Andrea Righi and Joel Fernandes, with fixes by Peter Zijlstra) RT scheduler updates: - Skip currently executing CPU in rto_next_cpu() (Chen Jinghuang) Entry code updates and performance improvements (Jinjie Ruan) This is part of the scheduler tree in this cycle due to inter- dependencies with the RSEQ based time slice extension work: - Remove unused syscall argument from syscall_trace_enter() - Rework syscall_exit_to_user_mode_work() for architecture reuse - Add arch_ptrace_report_syscall_entry/exit() - Inline syscall_exit_work() and syscall_trace_enter() Scheduler core updates (Peter Zijlstra): - Rework sched_class::wakeup_preempt() and rq_modified_*() - Avoid rq->lock bouncing in sched_balance_newidle() - Rename rcu_dereference_check_sched_domain() => rcu_dereference_sched_domain() - <linux/compiler_types.h>: Add the __signed_scalar_typeof() helper Fair scheduler updates/refactoring (Peter Zijlstra and Ingo Molnar): - Fold the sched_avg update - Change rcu_dereference_check_sched_domain() to rcu-sched - Switch to rcu_dereference_all() - Remove superfluous rcu_read_lock() - Limit hrtick work - Join two #ifdef CONFIG_FAIR_GROUP_SCHED blocks - Clean up comments in 'struct cfs_rq' - Separate se->vlag from se->vprot - Rename cfs_rq::avg_load to cfs_rq::sum_weight - Rename cfs_rq::avg_vruntime to ::sum_w_vruntime & helper functions - Introduce and use the vruntime_cmp() and vruntime_op() wrappers for wrapped-signed aritmetics - Sort out 'blocked_load*' namespace noise Scheduler debugging code updates: - Export hidden tracepoints to modules (Gabriele Monaco) - Convert copy_from_user() + kstrtouint() to kstrtouint_from_user() (Fushuai Wang) - Add assertions to QUEUE_CLASS (Peter Zijlstra) - hrtimer: Fix tracing oddity (Thomas Gleixner) Misc fixes and cleanups: - Re-evaluate scheduling when migrating queued tasks out of throttled cgroups (Zicheng Qu) - Remove task_struct->faults_disabled_mapping (Christoph Hellwig) - Fix math notation errors in avg_vruntime comment (Zhan Xusheng) - sched/cpufreq: Use %pe format for PTR_ERR() printing (zenghongling)" * tag 'sched-core-2026-02-09' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (64 commits) sched: Re-evaluate scheduling when migrating queued tasks out of throttled cgroups sched/cpufreq: Use %pe format for PTR_ERR() printing sched/rt: Skip currently executing CPU in rto_next_cpu() sched/clock: Avoid false sharing for sched_clock_irqtime selftests/sched_ext: Add test for DL server total_bw consistency selftests/sched_ext: Add test for sched_ext dl_server sched/debug: Fix dl_server (re)start conditions sched/debug: Add support to change sched_ext server params sched_ext: Add a DL server for sched_ext tasks sched/debug: Stop and start server based on if it was active sched/debug: Fix updating of ppos on server write ops sched/deadline: Clear the defer params entry: Inline syscall_exit_work() and syscall_trace_enter() entry: Add arch_ptrace_report_syscall_entry/exit() entry: Rework syscall_exit_to_user_mode_work() for architecture reuse entry: Remove unused syscall argument from syscall_trace_enter() sched: remove task_struct->faults_disabled_mapping sched: Update rq->avg_idle when a task is moved to an idle CPU selftests/rseq: Add rseq slice histogram script hrtimer: Fix trace oddity ...
2026-02-10Merge tag 'locking-core-2026-02-08' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull locking updates from Ingo Molnar: "Lock debugging: - Implement compiler-driven static analysis locking context checking, using the upcoming Clang 22 compiler's context analysis features (Marco Elver) We removed Sparse context analysis support, because prior to removal even a defconfig kernel produced 1,700+ context tracking Sparse warnings, the overwhelming majority of which are false positives. On an allmodconfig kernel the number of false positive context tracking Sparse warnings grows to over 5,200... On the plus side of the balance actual locking bugs found by Sparse context analysis is also rather ... sparse: I found only 3 such commits in the last 3 years. So the rate of false positives and the maintenance overhead is rather high and there appears to be no active policy in place to achieve a zero-warnings baseline to move the annotations & fixers to developers who introduce new code. Clang context analysis is more complete and more aggressive in trying to find bugs, at least in principle. Plus it has a different model to enabling it: it's enabled subsystem by subsystem, which results in zero warnings on all relevant kernel builds (as far as our testing managed to cover it). Which allowed us to enable it by default, similar to other compiler warnings, with the expectation that there are no warnings going forward. This enforces a zero-warnings baseline on clang-22+ builds (Which are still limited in distribution, admittedly) Hopefully the Clang approach can lead to a more maintainable zero-warnings status quo and policy, with more and more subsystems and drivers enabling the feature. Context tracking can be enabled for all kernel code via WARN_CONTEXT_ANALYSIS_ALL=y (default disabled), but this will generate a lot of false positives. ( Having said that, Sparse support could still be added back, if anyone is interested - the removal patch is still relatively straightforward to revert at this stage. ) Rust integration updates: (Alice Ryhl, Fujita Tomonori, Boqun Feng) - Add support for Atomic<i8/i16/bool> and replace most Rust native AtomicBool usages with Atomic<bool> - Clean up LockClassKey and improve its documentation - Add missing Send and Sync trait implementation for SetOnce - Make ARef Unpin as it is supposed to be - Add __rust_helper to a few Rust helpers as a preparation for helper LTO - Inline various lock related functions to avoid additional function calls WW mutexes: - Extend ww_mutex tests and other test-ww_mutex updates (John Stultz) Misc fixes and cleanups: - rcu: Mark lockdep_assert_rcu_helper() __always_inline (Arnd Bergmann) - locking/local_lock: Include more missing headers (Peter Zijlstra) - seqlock: fix scoped_seqlock_read kernel-doc (Randy Dunlap) - rust: sync: Replace `kernel::c_str!` with C-Strings (Tamir Duberstein)" * tag 'locking-core-2026-02-08' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (90 commits) locking/rwlock: Fix write_trylock_irqsave() with CONFIG_INLINE_WRITE_TRYLOCK rcu: Mark lockdep_assert_rcu_helper() __always_inline compiler-context-analysis: Remove __assume_ctx_lock from initializers tomoyo: Use scoped init guard crypto: Use scoped init guard kcov: Use scoped init guard compiler-context-analysis: Introduce scoped init guards cleanup: Make __DEFINE_LOCK_GUARD handle commas in initializers seqlock: fix scoped_seqlock_read kernel-doc tools: Update context analysis macros in compiler_types.h rust: sync: Replace `kernel::c_str!` with C-Strings rust: sync: Inline various lock related methods rust: helpers: Move #define __rust_helper out of atomic.c rust: wait: Add __rust_helper to helpers rust: time: Add __rust_helper to helpers rust: task: Add __rust_helper to helpers rust: sync: Add __rust_helper to helpers rust: refcount: Add __rust_helper to helpers rust: rcu: Add __rust_helper to helpers rust: processor: Add __rust_helper to helpers ...
2026-02-10Merge tag 'kmalloc_obj-v7.0-rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux Pull kmalloc_obj updates from Kees Cook: "Introduce the kmalloc_obj* family of APIs for switching to type-based kmalloc allocations, away from purely size-based allocations. Discussed on lkml, with you, and at Linux Plumbers. It's been in -next for the entire dev cycle. Before the merge window closes, I'd like to send the treewide change (generated from the Coccinelle script included here), which mechanically converts almost 20k callsites from kmalloc* to kmalloc_obj*: 8007 files changed, 19980 insertions(+), 20838 deletions(-) This change needed fixes for mismatched types (since now the return type from allocations is a pointer to the requested type, not "void *"), and I've been fixing these over the last 4 releases. These fixes have mostly been trivial mismatches with const qualifiers or accidentally identical sizes (e.g. same object size: "struct kvec" vs "struct iovec", or differing pointers to pointers), but I did catch one case of too-small allocation. Summary: - Introduce kmalloc_obj*() family of type-based allocator APIs - checkpatch: Suggest kmalloc_obj family for sizeof allocations - coccinelle: Add kmalloc_objs conversion script" * tag 'kmalloc_obj-v7.0-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux: coccinelle: Add kmalloc_objs conversion script slab: Introduce kmalloc_flex() and family compiler_types: Introduce __flex_counter() and family checkpatch: Suggest kmalloc_obj family for sizeof allocations slab: Introduce kmalloc_obj() and family
2026-02-08kcsan, compiler_types: avoid duplicate type issues in BPF Type FormatAlan Maguire
Enabling KCSAN is causing a large number of duplicate types in BTF for core kernel structs like task_struct [1]. This is due to the definition in include/linux/compiler_types.h `#ifdef __SANITIZE_THREAD__ ... `#define __data_racy volatile .. `#else ... `#define __data_racy ... `#endif Because some objects in the kernel are compiled without KCSAN flags (KCSAN_SANITIZE) we sometimes get the empty __data_racy annotation for objects; as a result we get multiple conflicting representations of the associated structs in DWARF, and these lead to multiple instances of core kernel types in BTF since they cannot be deduplicated due to the additional modifier in some instances. Moving the __data_racy definition under CONFIG_KCSAN avoids this problem, since the volatile modifier will be present for both KCSAN and KCSAN_SANITIZE objects in a CONFIG_KCSAN=y kernel. Link: https://lkml.kernel.org/r/20260116091730.324322-1-alan.maguire@oracle.com Fixes: 31f605a308e6 ("kcsan, compiler_types: Introduce __data_racy type qualifier") Signed-off-by: Alan Maguire <alan.maguire@oracle.com> Reported-by: Nilay Shroff <nilay@linux.ibm.com> Tested-by: Nilay Shroff <nilay@linux.ibm.com> Suggested-by: Marco Elver <elver@google.com> Reviewed-by: Marco Elver <elver@google.com> Acked-by: Yonghong Song <yonghong.song@linux.dev> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Andrii Nakryiko <andrii.nakryiko@gmail.com> Cc: Bart van Assche <bvanassche@acm.org> Cc: Daniel Borkman <daniel@iogearbox.net> Cc: Eduard Zingerman <eddyz87@gmail.com> Cc: Hao Luo <haoluo@google.com> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Jason A. Donenfeld <jason@zx2c4.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: John Fastabend <john.fastabend@gmail.com> Cc: Kees Cook <kees@kernel.org> Cc: KP Singh <kpsingh@kernel.org> Cc: Martin KaFai Lau <martin.lau@linux.dev> Cc: Miguel Ojeda <ojeda@kernel.org> Cc: Naman Jain <namjain@linux.microsoft.com> Cc: Nathan Chancellor <nathan@kernel.org> Cc: "Paul E . McKenney" <paulmck@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stanislav Fomichev <sdf@fomichev.me> Cc: Uros Bizjak <ubizjak@gmail.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-02-03Merge branch 'v6.19-rc8'Peter Zijlstra
Update to avoid conflicts with /urgent patches. Signed-off-by: Peter Zijlstra <peterz@infradead.org>
2026-01-18compiler: Use __typeof_unqual__() for __unqual_scalar_typeof()Peter Zijlstra
The recent changes to get_unaligned() resulted in a new sparse warning: net/rds/ib_cm.c:96:35: sparse: sparse: incorrect type in argument 1 (different modifiers) @@ expected void * @@ got restricted __be64 const * @@ net/rds/ib_cm.c:96:35: sparse: expected void * net/rds/ib_cm.c:96:35: sparse: got restricted __be64 const * The updated get_unaligned_t() uses __unqual_scalar_typeof() to get an unqualified type. This works correctly for the compilers, but fails for sparse when the data type is __be64 (or any other __beNN variant). On sparse runs (C=[12]) __beNN types are annotated with __attribute__((bitwise)). That annotation allows sparse to detect incompatible operations on __beNN variables, but it also prevents sparse from evaluating the _Generic() in __unqual_scalar_typeof() and map __beNN to a unqualified scalar type, so it ends up with the default, i.e. the original qualified type of a 'const __beNN' pointer. That then ends up as the first pointer argument to builtin_memcpy(), which obviously causes the above sparse warnings. The sparse git tree supports typeof_unqual() now, which allows to use it instead of the _Generic() based __unqual_scalar_typeof(). With that sparse correctly evaluates the unqualified type and keeps the __beNN logic intact. The downside is that this requires a top of tree sparse build and an old sparse version will emit a metric ton of incomprehensible error messages before it dies with a segfault. Therefore implement a sanity check which validates that the checker is available and capable of handling typeof_unqual(). Emit a warning if not so the user can take informed action. [ tglx: Move the evaluation of USE_TYPEOF_UNQUAL to compiler_types.h so it is set before use and implement the sanity checker ] Reported-by: kernel test robot <lkp@intel.com> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Thomas Gleixner <tglx@kernel.org> Acked-by: Ian Rogers <irogers@google.com> Link: https://patch.msgid.link/87ecnp2zh3.ffs@tglx Closes: https://lore.kernel.org/oe-kbuild-all/202601150001.sKSN644a-lkp@intel.com/
2026-01-17compiler_types.h: Attributes: Add __counted_by_ptr macroBill Wendling
Introduce __counted_by_ptr(), which works like __counted_by(), but for pointer struct members. struct foo { int a, b, c; char *buffer __counted_by_ptr(bytes); short nr_bars; struct bar *bars __counted_by_ptr(nr_bars); size_t bytes; }; Because "counted_by" can only be applied to pointer members in very recent compiler versions, its application ends up needing to be distinct from flexibe array "counted_by" annotations, hence a separate macro. This is a reworking of Kees' previous patch [1]. Link: https://lore.kernel.org/all/20251020220118.1226740-1-kees@kernel.org/ [1] Co-developed-by: Kees Cook <kees@kernel.org> Signed-off-by: Bill Wendling <morbo@google.com> Link: https://patch.msgid.link/20260116005838.2419118-1-morbo@google.com Signed-off-by: Kees Cook <kees@kernel.org>
2026-01-14compiler_types: Introduce __flex_counter() and familyKees Cook
Introduce __flex_counter() which wraps __builtin_counted_by_ref(), as newly introduced by GCC[1] and Clang[2]. Use of __flex_counter() allows access to the counter member of a struct's flexible array member when it has been annotated with __counted_by(). Introduce typeof_flex_counter(), overflows_flex_counter_type(), and __set_flex_counter() to provide the needed _Generic() wrappers to get sane results out of __flex_counter(). For example, with: struct foo { int counter; short array[] __counted_by(counter); } *p; __flex_counter(p->array) will resolve to: &p->counter typeof_flex_counter(p->array) will resolve to "int". (If p->array was not annotated, it would resolve to "size_t".) overflows_flex_counter_type(typeof(*p), array, COUNT) is the same as: COUNT <= type_max(p->counter) && COUNT >= type_min(p->counter) (If p->array was not annotated it would return true since everything fits in size_t.) __set_flex_counter(p->array, COUNT) is the same as: p->counter = COUNT; (It is a no-op if p->array is not annotated with __counted_by().) Link: https://patch.msgid.link/20251203233036.3212363-3-kees@kernel.org Signed-off-by: Kees Cook <kees@kernel.org>
2026-01-05compiler_types: Move lock checking attributes to compiler-context-analysis.hMarco Elver
The conditional definition of lock checking macros and attributes is about to become more complex. Factor them out into their own header for better readability, and to make it obvious which features are supported by which mode (currently only Sparse). This is the first step towards generalizing towards "context analysis". No functional change intended. Signed-off-by: Marco Elver <elver@google.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Bart Van Assche <bvanassche@acm.org> Link: https://patch.msgid.link/20251219154418.3592607-2-elver@google.com
2025-12-20clang: work around asm output constraint problemsEric Dumazet
Work around clang problems with "=rm" asm constraint. clang seems to always chose the memory output, while it is almost always the worst choice. Add ASM_OUTPUT_RM so that we can replace "=rm" constraint where it matters for clang, while not penalizing gcc. Signed-off-by: Eric Dumazet <edumazet@google.com> Suggested-by: Uros Bizjak <ubizjak@gmail.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2025-12-14<linux/compiler_types.h>: Add the __signed_scalar_typeof() helperPeter Zijlstra
Define __signed_scalar_typeof() to declare a signed scalar type, leaving non-scalar types unchanged. To be used to clean up the scheduler load-balancing code a bit. [ mingo: Split off this patch from the scheduler patch. ] Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Cc: Dietmar Eggemann <dietmar.eggemann@arm.com> Cc: Juri Lelli <juri.lelli@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mel Gorman <mgorman@suse.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Shrikanth Hegde <sshegde@linux.ibm.com> Cc: Valentin Schneider <vschneid@redhat.com> Cc: Vincent Guittot <vincent.guittot@linaro.org> Link: https://patch.msgid.link/20251127154725.413564507@infradead.org
2025-12-10Merge tag 'auto-type-conversion-for-v6.19-rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/hpa/linux-auto Pull __auto_type to auto conversion from Peter Anvin: "Convert '__auto_type' to 'auto', defining a macro for 'auto' unless C23+ is in use" * tag 'auto-type-conversion-for-v6.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/hpa/linux-auto: tools/virtio: replace "__auto_type" with "auto" selftests/bpf: replace "__auto_type" with "auto" arch/x86: replace "__auto_type" with "auto" arch/nios2: replace "__auto_type" and adjacent equivalent with "auto" fs/proc: replace "__auto_type" with "const auto" include/linux: change "__auto_type" to "auto" compiler_types.h: add "auto" as a macro for "__auto_type"
2025-12-08compiler_types.h: add "auto" as a macro for "__auto_type"H. Peter Anvin
"auto" was defined as a keyword back in the K&R days, but as a storage type specifier. No one ever used it, since it was and is the default storage type for local variables. C++11 recycled the keyword to allow a type to be declared based on the type of an initializer. This was finally adopted into standard C in C23. gcc and clang provide the "__auto_type" alias keyword as an extension for pre-C23, however, there is no reason to pollute the bulk of the source base with this temporary keyword; instead define "auto" as a macro unless the compiler is running in C23+ mode. This macro is added in <linux/compiler_types.h> because that header is included in some of the tools headers, wheres <linux/compiler.h> is not as it has a bunch of very kernel-specific things in it. [ Cc: stable to reduce potential backporting burden. ] Signed-off-by: H. Peter Anvin (Intel) <hpa@zytor.com> Acked-by: Miguel Ojeda <ojeda@kernel.org> Cc: <stable@kernel.org>
2025-12-09Merge tag 'hyperv-next-signed-20251207' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux Pull hyperv updates from Wei Liu: - Enhancements to Linux as the root partition for Microsoft Hypervisor: - Support a new mode called L1VH, which allows Linux to drive the hypervisor running the Azure Host directly - Support for MSHV crash dump collection - Allow Linux's memory management subsystem to better manage guest memory regions - Fix issues that prevented a clean shutdown of the whole system on bare metal and nested configurations - ARM64 support for the MSHV driver - Various other bug fixes and cleanups - Add support for Confidential VMBus for Linux guest on Hyper-V - Secure AVIC support for Linux guests on Hyper-V - Add the mshv_vtl driver to allow Linux to run as the secure kernel in a higher virtual trust level for Hyper-V * tag 'hyperv-next-signed-20251207' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux: (58 commits) mshv: Cleanly shutdown root partition with MSHV mshv: Use reboot notifier to configure sleep state mshv: Add definitions for MSHV sleep state configuration mshv: Add support for movable memory regions mshv: Add refcount and locking to mem regions mshv: Fix huge page handling in memory region traversal mshv: Move region management to mshv_regions.c mshv: Centralize guest memory region destruction mshv: Refactor and rename memory region handling functions mshv: adjust interrupt control structure for ARM64 Drivers: hv: use kmalloc_array() instead of kmalloc() mshv: Add ioctl for self targeted passthrough hvcalls Drivers: hv: Introduce mshv_vtl driver Drivers: hv: Export some symbols for mshv_vtl static_call: allow using STATIC_CALL_TRAMP_STR() from assembly mshv: Extend create partition ioctl to support cpu features mshv: Allow mappings that overlap in uaddr mshv: Fix create memory region overlap check mshv: add WQ_PERCPU to alloc_workqueue users Drivers: hv: Use kmalloc_array() instead of kmalloc() ...
2025-12-02Merge tag 'libcrypto-at-least-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/ebiggers/linux Pull 'at_least' array size update from Eric Biggers: "C supports lower bounds on the sizes of array parameters, using the static keyword as follows: 'void f(int a[static 32]);'. This allows the compiler to warn about a too-small array being passed. As discussed, this reuse of the 'static' keyword, while standard, is a bit obscure. Therefore, add an alias 'at_least' to compiler_types.h. Then, add this 'at_least' annotation to the array parameters of various crypto library functions" * tag 'libcrypto-at-least-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiggers/linux: lib/crypto: sha2: Add at_least decoration to fixed-size array params lib/crypto: sha1: Add at_least decoration to fixed-size array params lib/crypto: poly1305: Add at_least decoration to fixed-size array params lib/crypto: md5: Add at_least decoration to fixed-size array params lib/crypto: curve25519: Add at_least decoration to fixed-size array params lib/crypto: chacha: Add at_least decoration to fixed-size array params lib/crypto: chacha20poly1305: Statically check fixed array lengths compiler_types: introduce at_least parameter decoration pseudo keyword wifi: iwlwifi: trans: rename at_least variable to min_mode
2025-11-23compiler_types: introduce at_least parameter decoration pseudo keywordJason A. Donenfeld
Clang and recent gcc support warning if they are able to prove that the user is passing to a function an array that is too short in size. For example: void blah(unsigned char herp[at_least 7]); static void schma(void) { unsigned char good[] = { 1, 2, 3, 4, 5, 6, 7 }; unsigned char bad[] = { 1, 2, 3, 4, 5, 6 }; blah(good); blah(bad); } The notation here, `static 7`, which this commit makes explicit by allowing us to write it as `at_least 7`, means that it's incorrect to pass anything less than 7 elements. This is section 6.7.5.3 of C99: If the keyword static also appears within the [ and ] of the array type derivation, then for each call to the function, the value of the corresponding actual argument shall provide access to the first element of an array with at least as many elements as specified by the size expression. Here is the output from gcc 15: zx2c4@thinkpad /tmp $ gcc -c a.c a.c: In function ‘schma’: a.c:9:9: warning: ‘blah’ accessing 7 bytes in a region of size 6 [-Wstringop-overflow=] 9 | blah(bad); | ^~~~~~~~~ a.c:9:9: note: referencing argument 1 of type ‘unsigned char[7]’ a.c:2:6: note: in a call to function ‘blah’ 2 | void blah(unsigned char herp[at_least 7]); | ^~~~ And from clang 21: zx2c4@thinkpad /tmp $ clang -c a.c a.c:9:2: warning: array argument is too small; contains 6 elements, callee requires at least 7 [-Warray-bounds] 9 | blah(bad); | ^ ~~~ a.c:2:25: note: callee declares array parameter as static here 2 | void blah(unsigned char herp[at_least 7]); | ^ ~~~~~~~~~~ 1 warning generated. So these are covered by, variously, -Wstringop-overflow and -Warray-bounds. Acked-by: Ard Biesheuvel <ardb@kernel.org> Signed-off-by: "Jason A. Donenfeld" <Jason@zx2c4.com> Link: https://lore.kernel.org/r/20251123054819.2371989-3-Jason@zx2c4.com Signed-off-by: Eric Biggers <ebiggers@kernel.org>
2025-11-15static_call: allow using STATIC_CALL_TRAMP_STR() from assemblyNaman Jain
STATIC_CALL_TRAMP_STR() could not be used from .S files because static_call_types.h was not safe to include in assembly as it pulled in C types/constructs that are unavailable under __ASSEMBLY__. Make the header assembly-friendly by adding __ASSEMBLY__ checks and providing only the minimal definitions needed for assembly, so that it can be safely included by .S code. This enables emitting the static call trampoline symbol name via STATIC_CALL_TRAMP_STR() directly in assembly sources, to be used with 'call' instruction. Also, move a certain definitions out of __ASSEMBLY__ checks in compiler_types.h to meet the dependencies. No functional change for C compilation. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Naman Jain <namjain@linux.microsoft.com> Signed-off-by: Wei Liu <wei.liu@kernel.org>
2025-11-09Merge tag 'kbuild-fixes-6.18-3' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/kbuild/linux Pull Kbuild fixes from Nathan Chancellor: - Strip trailing padding bytes from modules.builtin.modinfo to fix error during modules_install with certain versions of kmod - Drop unused static inline function warning in .c files with clang from W=1 to W=2 - Ensure kernel-doc.py invocations use the PYTHON3 make variable to ensure user's choice of Python interpreter is always respected * tag 'kbuild-fixes-6.18-3' of git://git.kernel.org/pub/scm/linux/kernel/git/kbuild/linux: kbuild: Let kernel-doc.py use PYTHON3 override compiler_types: Move unused static inline functions warning to W=2 kbuild: Strip trailing padding bytes from modules.builtin.modinfo
2025-11-07compiler_types: Move unused static inline functions warning to W=2Peter Zijlstra
Per Nathan, clang catches unused "static inline" functions in C files since commit 6863f5643dd7 ("kbuild: allow Clang to find unused static inline functions for W=1 build"). Linus said: > So I entirely ignore W=1 issues, because I think so many of the extra > warnings are bogus. > > But if this one in particular is causing more problems than most - > some teams do seem to use W=1 as part of their test builds - it's fine > to send me a patch that just moves bad warnings to W=2. > > And if anybody uses W=2 for their test builds, that's THEIR problem.. Here is the change to bump the warning from W=1 to W=2. Fixes: 6863f5643dd7 ("kbuild: allow Clang to find unused static inline functions for W=1 build") Signed-off-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Link: https://patch.msgid.link/20251106105000.2103276-1-andriy.shevchenko@linux.intel.com [nathan: Adjust comment as well] Signed-off-by: Nathan Chancellor <nathan@kernel.org>
2025-10-29compiler_types: Introduce __nocfi_genericNathan Chancellor
There are two different ways that LLVM can expand kCFI operand bundles in LLVM IR: generically in the middle end or using an architecture specific sequence when lowering LLVM IR to machine code in the backend. The generic pass allows any architecture to take advantage of kCFI but the expansion of these bundles in the middle end can mess with optimizations that may turn indirect calls into direct calls when the call target is known at compile time, such as after inlining. Add __nocfi_generic, dependent on an architecture selecting CONFIG_ARCH_USES_CFI_GENERIC_LLVM_PASS, to disable kCFI bundle generation in functions where only the generic kCFI pass may cause problems. Link: https://github.com/ClangBuiltLinux/linux/issues/2124 Signed-off-by: Nathan Chancellor <nathan@kernel.org> Link: https://patch.msgid.link/20251025-idpf-fix-arm-kcfi-build-error-v1-1-ec57221153ae@kernel.org Signed-off-by: Kees Cook <kees@kernel.org>
2025-10-11Merge tag 'x86_core_for_v6.18_rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull more x86 updates from Borislav Petkov: - Remove a bunch of asm implementing condition flags testing in KVM's emulator in favor of int3_emulate_jcc() which is written in C - Replace KVM fastops with C-based stubs which avoids problems with the fastop infra related to latter not adhering to the C ABI due to their special calling convention and, more importantly, bypassing compiler control-flow integrity checking because they're written in asm - Remove wrongly used static branches and other ugliness accumulated over time in hyperv's hypercall implementation with a proper static function call to the correct hypervisor call variant - Add some fixes and modifications to allow running FRED-enabled kernels in KVM even on non-FRED hardware - Add kCFI improvements like validating indirect calls and prepare for enabling kCFI with GCC. Add cmdline params documentation and other code cleanups - Use the single-byte 0xd6 insn as the official #UD single-byte undefined opcode instruction as agreed upon by both x86 vendors - Other smaller cleanups and touchups all over the place * tag 'x86_core_for_v6.18_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (24 commits) x86,retpoline: Optimize patch_retpoline() x86,ibt: Use UDB instead of 0xEA x86/cfi: Remove __noinitretpoline and __noretpoline x86/cfi: Add "debug" option to "cfi=" bootparam x86/cfi: Standardize on common "CFI:" prefix for CFI reports x86/cfi: Document the "cfi=" bootparam options x86/traps: Clarify KCFI instruction layout compiler_types.h: Move __nocfi out of compiler-specific header objtool: Validate kCFI calls x86/fred: KVM: VMX: Always use FRED for IRQs when CONFIG_X86_FRED=y x86/fred: Play nice with invoking asm_fred_entry_from_kvm() on non-FRED hardware x86/fred: Install system vector handlers even if FRED isn't fully enabled x86/hyperv: Use direct call to hypercall-page x86/hyperv: Clean up hv_do_hypercall() KVM: x86: Remove fastops KVM: x86: Convert em_salc() to C KVM: x86: Introduce EM_ASM_3WCL KVM: x86: Introduce EM_ASM_1SRC2 KVM: x86: Introduce EM_ASM_2CL KVM: x86: Introduce EM_ASM_2W ...
2025-09-18compiler_types: Add __assume macroHeiko Carstens
Make the statement attribute "assume" with a new __assume macro available. The assume attribute is used to indicate that a certain condition is assumed to be true. Compilers may or may not use this indication to generate optimized code. If this condition is violated at runtime, the behavior is undefined. Note that the clang documentation states that optimizers may react differently to this attribute, and this may even have a negative performance impact. Therefore this attribute should be used with care. Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Reviewed-by: Nathan Chancellor <nathan@kernel.org> Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2025-09-04compiler_types.h: Move __nocfi out of compiler-specific headerKees Cook
Prepare for GCC KCFI support and move the __nocfi attribute from compiler-clang.h to compiler_types.h. This was already gated by CONFIG_CFI_CLANG, so this remains safe for non-KCFI GCC builds. Signed-off-by: Kees Cook <kees@kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Nathan Chancellor <nathan@kernel.org> Link: https://lore.kernel.org/r/20250904034656.3670313-1-kees@kernel.org
2025-07-29compiler_types: Provide __no_kstack_erase to disable coverage only on ClangKees Cook
In order to support Clang's stack depth tracking (for Linux's kstack_erase feature), the coverage sanitizer needed to be disabled for __init (and __head) section code. Doing this universally (i.e. for GCC too) created a number of unexpected problems, ranging from changes to inlining logic to failures to DCE code on earlier GCC versions. Since this change is only needed for Clang, specialize it so that GCC doesn't see the change as it isn't needed there (the GCC implementation of kstack_erase uses a GCC plugin that removes stack depth tracking instrumentation from __init sections during a late pass in the IR). Successfully build and boot tested with GCC 12 and Clang 22. Fixes: 381a38ea53d2 ("init.h: Disable sanitizer coverage for __init and __head") Reported-by: kernel test robot <lkp@intel.com> Closes: https://lore.kernel.org/oe-kbuild-all/202507270258.neWuiXLd-lkp@intel.com/ Reported-by: syzbot+5245cb609175fb6e8122@syzkaller.appspotmail.com Closes: https://lore.kernel.org/all/6888d004.a00a0220.26d0e1.0004.GAE@google.com/ Reviewed-by: Nathan Chancellor <nathan@kernel.org> Reviewed-by: Marco Elver <elver@google.com> Link: https://lore.kernel.org/r/20250729234055.it.233-kees@kernel.org Signed-off-by: Kees Cook <kees@kernel.org>
2025-05-31Merge tag 'mm-nonmm-stable-2025-05-31-15-28' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Pull non-MM updates from Andrew Morton: - "hung_task: extend blocking task stacktrace dump to semaphore" from Lance Yang enhances the hung task detector. The detector presently dumps the blocking tasks's stack when it is blocked on a mutex. Lance's series extends this to semaphores - "nilfs2: improve sanity checks in dirty state propagation" from Wentao Liang addresses a couple of minor flaws in nilfs2 - "scripts/gdb: Fixes related to lx_per_cpu()" from Illia Ostapyshyn fixes a couple of issues in the gdb scripts - "Support kdump with LUKS encryption by reusing LUKS volume keys" from Coiby Xu addresses a usability problem with kdump. When the dump device is LUKS-encrypted, the kdump kernel may not have the keys to the encrypted filesystem. A full writeup of this is in the series [0/N] cover letter - "sysfs: add counters for lockups and stalls" from Max Kellermann adds /sys/kernel/hardlockup_count and /sys/kernel/hardlockup_count and /sys/kernel/rcu_stall_count - "fork: Page operation cleanups in the fork code" from Pasha Tatashin implements a number of code cleanups in fork.c - "scripts/gdb/symbols: determine KASLR offset on s390 during early boot" from Ilya Leoshkevich fixes some s390 issues in the gdb scripts * tag 'mm-nonmm-stable-2025-05-31-15-28' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (67 commits) llist: make llist_add_batch() a static inline delayacct: remove redundant code and adjust indentation squashfs: add optional full compressed block caching crash_dump, nvme: select CONFIGFS_FS as built-in scripts/gdb/symbols: determine KASLR offset on s390 during early boot scripts/gdb/symbols: factor out pagination_off() scripts/gdb/symbols: factor out get_vmlinux() kernel/panic.c: format kernel-doc comments mailmap: update and consolidate Casey Connolly's name and email nilfs2: remove wbc->for_reclaim handling fork: define a local GFP_VMAP_STACK fork: check charging success before zeroing stack fork: clean-up naming of vm_stack/vm_struct variables in vmap stacks code fork: clean-up ifdef logic around stack allocation kernel/rcu/tree_stall: add /sys/kernel/rcu_stall_count kernel/watchdog: add /sys/kernel/{hard,soft}lockup_count x86/crash: make the page that stores the dm crypt keys inaccessible x86/crash: pass dm crypt keys to kdump kernel Revert "x86/mm: Remove unused __set_memory_prot()" crash_dump: retrieve dm crypt keys in kdump kernel ...
2025-05-11compiler_types.h: fix "unused variable" in __compiletime_assert()Marc Herbert
This refines commit c03567a8e8d5 ("include/linux/compiler.h: don't perform compiletime_assert with -O0") and restores #ifdef __OPTIMIZE__ symmetry by evaluating the 'condition' variable in both compile-time variants of __compiletimeassert(). As __OPTIMIZE__ is always true by default, this commit does not change anything by default. But it fixes warnings with _non-default_ CFLAGS like for instance this: make CFLAGS_tcp.o='-Og -U__OPTIMIZE__' from net/ipv4/tcp.c:273: include/net/sch_generic.h: In function `qdisc_cb_private_validate': include/net/sch_generic.h:511:30: error: unused variable `qcb' [-Werror=unused-variable] { struct qdisc_skb_cb *qcb; BUILD_BUG_ON(sizeof(skb->cb) < sizeof(*qcb)); ... } [akpm@linux-foundation.org: regularize comment layout, reflow comment] Link: https://lkml.kernel.org/r/20250424194048.652571-1-marc.herbert@linux.intel.com Signed-off-by: Marc Herbert <Marc.Herbert@linux.intel.com> Cc: Alexander Potapenko <glider@google.com> Cc: Changbin Du <changbin.du@intel.com> Cc: Jan Hendrik Farr <kernel@jfarr.cc> Cc: Macro Elver <elver@google.com> Cc: Miguel Ojeda <ojeda@kernel.org> Cc: Tony Ambardar <tony.ambardar@gmail.com> Cc: Uros Bizjak <ubizjak@gmail.com> Cc: Kees Cook <kees@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-04-28compiler_types: Identify compiler versions for __builtin_dynamic_object_sizeKees Cook
Clarify when __builtin_dynamic_object_size() is available. All our supported Clang versions support it. GCC 12 and later support it. Link to documentation for both. Acked-by: Miguel Ojeda <ojeda@kernel.org> Link: https://lore.kernel.org/r/20250416172016.work.154-kees@kernel.org Signed-off-by: Kees Cook <kees@kernel.org>
2025-04-01Merge tag 'mm-stable-2025-03-30-16-52' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Pull MM updates from Andrew Morton: - The series "Enable strict percpu address space checks" from Uros Bizjak uses x86 named address space qualifiers to provide compile-time checking of percpu area accesses. This has caused a small amount of fallout - two or three issues were reported. In all cases the calling code was found to be incorrect. - The series "Some cleanup for memcg" from Chen Ridong implements some relatively monir cleanups for the memcontrol code. - The series "mm: fixes for device-exclusive entries (hmm)" from David Hildenbrand fixes a boatload of issues which David found then using device-exclusive PTE entries when THP is enabled. More work is needed, but this makes thins better - our own HMM selftests now succeed. - The series "mm: zswap: remove z3fold and zbud" from Yosry Ahmed remove the z3fold and zbud implementations. They have been deprecated for half a year and nobody has complained. - The series "mm: further simplify VMA merge operation" from Lorenzo Stoakes implements numerous simplifications in this area. No runtime effects are anticipated. - The series "mm/madvise: remove redundant mmap_lock operations from process_madvise()" from SeongJae Park rationalizes the locking in the madvise() implementation. Performance gains of 20-25% were observed in one MADV_DONTNEED microbenchmark. - The series "Tiny cleanup and improvements about SWAP code" from Baoquan He contains a number of touchups to issues which Baoquan noticed when working on the swap code. - The series "mm: kmemleak: Usability improvements" from Catalin Marinas implements a couple of improvements to the kmemleak user-visible output. - The series "mm/damon/paddr: fix large folios access and schemes handling" from Usama Arif provides a couple of fixes for DAMON's handling of large folios. - The series "mm/damon/core: fix wrong and/or useless damos_walk() behaviors" from SeongJae Park fixes a few issues with the accuracy of kdamond's walking of DAMON regions. - The series "expose mapping wrprotect, fix fb_defio use" from Lorenzo Stoakes changes the interaction between framebuffer deferred-io and core MM. No functional changes are anticipated - this is preparatory work for the future removal of page structure fields. - The series "mm/damon: add support for hugepage_size DAMOS filter" from Usama Arif adds a DAMOS filter which permits the filtering by huge page sizes. - The series "mm: permit guard regions for file-backed/shmem mappings" from Lorenzo Stoakes extends the guard region feature from its present "anon mappings only" state. The feature now covers shmem and file-backed mappings. - The series "mm: batched unmap lazyfree large folios during reclamation" from Barry Song cleans up and speeds up the unmapping for pte-mapped large folios. - The series "reimplement per-vma lock as a refcount" from Suren Baghdasaryan puts the vm_lock back into the vma. Our reasons for pulling it out were largely bogus and that change made the code more messy. This patchset provides small (0-10%) improvements on one microbenchmark. - The series "Docs/mm/damon: misc DAMOS filters documentation fixes and improves" from SeongJae Park does some maintenance work on the DAMON docs. - The series "hugetlb/CMA improvements for large systems" from Frank van der Linden addresses a pile of issues which have been observed when using CMA on large machines. - The series "mm/damon: introduce DAMOS filter type for unmapped pages" from SeongJae Park enables users of DMAON/DAMOS to filter my the page's mapped/unmapped status. - The series "zsmalloc/zram: there be preemption" from Sergey Senozhatsky teaches zram to run its compression and decompression operations preemptibly. - The series "selftests/mm: Some cleanups from trying to run them" from Brendan Jackman fixes a pile of unrelated issues which Brendan encountered while runnimg our selftests. - The series "fs/proc/task_mmu: add guard region bit to pagemap" from Lorenzo Stoakes permits userspace to use /proc/pid/pagemap to determine whether a particular page is a guard page. - The series "mm, swap: remove swap slot cache" from Kairui Song removes the swap slot cache from the allocation path - it simply wasn't being effective. - The series "mm: cleanups for device-exclusive entries (hmm)" from David Hildenbrand implements a number of unrelated cleanups in this code. - The series "mm: Rework generic PTDUMP configs" from Anshuman Khandual implements a number of preparatoty cleanups to the GENERIC_PTDUMP Kconfig logic. - The series "mm/damon: auto-tune aggregation interval" from SeongJae Park implements a feedback-driven automatic tuning feature for DAMON's aggregation interval tuning. - The series "Fix lazy mmu mode" from Ryan Roberts fixes some issues in powerpc, sparc and x86 lazy MMU implementations. Ryan did this in preparation for implementing lazy mmu mode for arm64 to optimize vmalloc. - The series "mm/page_alloc: Some clarifications for migratetype fallback" from Brendan Jackman reworks some commentary to make the code easier to follow. - The series "page_counter cleanup and size reduction" from Shakeel Butt cleans up the page_counter code and fixes a size increase which we accidentally added late last year. - The series "Add a command line option that enables control of how many threads should be used to allocate huge pages" from Thomas Prescher does that. It allows the careful operator to significantly reduce boot time by tuning the parallalization of huge page initialization. - The series "Fix calculations in trace_balance_dirty_pages() for cgwb" from Tang Yizhou fixes the tracing output from the dirty page balancing code. - The series "mm/damon: make allow filters after reject filters useful and intuitive" from SeongJae Park improves the handling of allow and reject filters. Behaviour is made more consistent and the documention is updated accordingly. - The series "Switch zswap to object read/write APIs" from Yosry Ahmed updates zswap to the new object read/write APIs and thus permits the removal of some legacy code from zpool and zsmalloc. - The series "Some trivial cleanups for shmem" from Baolin Wang does as it claims. - The series "fs/dax: Fix ZONE_DEVICE page reference counts" from Alistair Popple regularizes the weird ZONE_DEVICE page refcount handling in DAX, permittig the removal of a number of special-case checks. - The series "refactor mremap and fix bug" from Lorenzo Stoakes is a preparatoty refactoring and cleanup of the mremap() code. - The series "mm: MM owner tracking for large folios (!hugetlb) + CONFIG_NO_PAGE_MAPCOUNT" from David Hildenbrand reworks the manner in which we determine whether a large folio is known to be mapped exclusively into a single MM. - The series "mm/damon: add sysfs dirs for managing DAMOS filters based on handling layers" from SeongJae Park adds a couple of new sysfs directories to ease the management of DAMON/DAMOS filters. - The series "arch, mm: reduce code duplication in mem_init()" from Mike Rapoport consolidates many per-arch implementations of mem_init() into code generic code, where that is practical. - The series "mm/damon/sysfs: commit parameters online via damon_call()" from SeongJae Park continues the cleaning up of sysfs access to DAMON internal data. - The series "mm: page_ext: Introduce new iteration API" from Luiz Capitulino reworks the page_ext initialization to fix a boot-time crash which was observed with an unusual combination of compile and cmdline options. - The series "Buddy allocator like (or non-uniform) folio split" from Zi Yan reworks the code to split a folio into smaller folios. The main benefit is lessened memory consumption: fewer post-split folios are generated. - The series "Minimize xa_node allocation during xarry split" from Zi Yan reduces the number of xarray xa_nodes which are generated during an xarray split. - The series "drivers/base/memory: Two cleanups" from Gavin Shan performs some maintenance work on the drivers/base/memory code. - The series "Add tracepoints for lowmem reserves, watermarks and totalreserve_pages" from Martin Liu adds some more tracepoints to the page allocator code. - The series "mm/madvise: cleanup requests validations and classifications" from SeongJae Park cleans up some warts which SeongJae observed during his earlier madvise work. - The series "mm/hwpoison: Fix regressions in memory failure handling" from Shuai Xue addresses two quite serious regressions which Shuai has observed in the memory-failure implementation. - The series "mm: reliable huge page allocator" from Johannes Weiner makes huge page allocations cheaper and more reliable by reducing fragmentation. - The series "Minor memcg cleanups & prep for memdescs" from Matthew Wilcox is preparatory work for the future implementation of memdescs. - The series "track memory used by balloon drivers" from Nico Pache introduces a way to track memory used by our various balloon drivers. - The series "mm/damon: introduce DAMOS filter type for active pages" from Nhat Pham permits users to filter for active/inactive pages, separately for file and anon pages. - The series "Adding Proactive Memory Reclaim Statistics" from Hao Jia separates the proactive reclaim statistics from the direct reclaim statistics. - The series "mm/vmscan: don't try to reclaim hwpoison folio" from Jinjiang Tu fixes our handling of hwpoisoned pages within the reclaim code. * tag 'mm-stable-2025-03-30-16-52' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (431 commits) mm/page_alloc: remove unnecessary __maybe_unused in order_to_pindex() x86/mm: restore early initialization of high_memory for 32-bits mm/vmscan: don't try to reclaim hwpoison folio mm/hwpoison: introduce folio_contain_hwpoisoned_page() helper cgroup: docs: add pswpin and pswpout items in cgroup v2 doc mm: vmscan: split proactive reclaim statistics from direct reclaim statistics selftests/mm: speed up split_huge_page_test selftests/mm: uffd-unit-tests support for hugepages > 2M docs/mm/damon/design: document active DAMOS filter type mm/damon: implement a new DAMOS filter type for active pages fs/dax: don't disassociate zero page entries MM documentation: add "Unaccepted" meminfo entry selftests/mm: add commentary about 9pfs bugs fork: use __vmalloc_node() for stack allocation docs/mm: Physical Memory: Populate the "Zones" section xen: balloon: update the NR_BALLOON_PAGES state hv_balloon: update the NR_BALLOON_PAGES state balloon_compaction: update the NR_BALLOON_PAGES state meminfo: add a per node counter for balloon drivers mm: remove references to folio in __memcg_kmem_uncharge_page() ...
2025-03-16percpu: repurpose __percpu tag as a named address space qualifierUros Bizjak
The patch introduces __percpu_qual define and repurposes __percpu tag as a named address space qualifier using the new define. Arches can now conditionally define __percpu_qual as their named address space qualifier for percpu variables. Link: https://lkml.kernel.org/r/20250127160709.80604-6-ubizjak@gmail.com Signed-off-by: Uros Bizjak <ubizjak@gmail.com> Acked-by: Nadav Amit <nadav.amit@gmail.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Dennis Zhou <dennis@kernel.org> Cc: Tejun Heo <tj@kernel.org> Cc: Christoph Lameter <cl@linux.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Ingo Molnar <mingo@kernel.org> Cc: Brian Gerst <brgerst@gmail.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Boqun Feng <boqun.feng@gmail.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: Eric Dumazet <edumazet@google.com> Cc: Jakub Kicinski <kuba@kernel.org> Cc: Kent Overstreet <kent.overstreet@linux.dev> Cc: Paolo Abeni <pabeni@redhat.com> Cc: Waiman Long <longman@redhat.com> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-03-12compiler_types: Introduce __nonstring_arrayKees Cook
GCC has expanded support of the "nonstring" attribute so that it can be applied to arrays of character arrays[1], which is needed to identify correct static initialization of those kinds of objects. Since this was not supported prior to GCC 15, we need to distinguish the usage of Linux's existing __nonstring macro for the attribute for non-multi-dimensional char arrays. Until GCC 15 is the minimum version, use __nonstring_array to mark arrays of non-string character arrays. (Regular non-string character arrays can continue to use __nonstring.) Once GCC 15 is the minimum compiler version we can replace all uses of __nonstring_array with just __nonstring and remove this macro. This allows for changes like this: -static const char table_sigs[][ACPI_NAMESEG_SIZE] __initconst = { +static const char table_sigs[][ACPI_NAMESEG_SIZE] __nonstring_array __initconst = { ACPI_SIG_BERT, ACPI_SIG_BGRT, ACPI_SIG_CPEP, ACPI_SIG_ECDT, Which will silence the coming -Wunterminated-string-initialization warnings in GCC 15: In file included from ../include/acpi/actbl.h:371, from ../include/acpi/acpi.h:26, from ../include/linux/acpi.h:26, from ../drivers/acpi/tables.c:19: ../include/acpi/actbl1.h:30:33: warning: initializer-string for array of 'char' truncates NUL terminator but destination lacks 'nonstring' attribute (5 chars into 4 available) [-Wunterminated-string-initialization] 30 | #define ACPI_SIG_BERT "BERT" /* Boot Error Record Table */ | ^~~~~~ ../drivers/acpi/tables.c:400:9: note: in expansion of macro 'ACPI_SIG_BERT' 400 | ACPI_SIG_BERT, ACPI_SIG_BGRT, ACPI_SIG_CPEP, ACPI_SIG_ECDT, | ^~~~~~~~~~~~~ ../include/acpi/actbl1.h:31:33: warning: initializer-string for array of 'char' truncates NUL terminator but destination lacks 'nonstring' attribute (5 chars into 4 available) [-Wunterminated-string-initialization] 31 | #define ACPI_SIG_BGRT "BGRT" /* Boot Graphics Resource Table */ | ^~~~~~ Link: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=117178 [1] Acked-by: Miguel Ojeda <ojeda@kernel.org> Link: https://lore.kernel.org/r/20250310214244.work.194-kees@kernel.org Signed-off-by: Kees Cook <kees@kernel.org>
2025-03-07ubsan/overflow: Rework integer overflow sanitizer option to turn on everythingKees Cook
Since we're going to approach integer overflow mitigation a type at a time, we need to enable all of the associated sanitizers, and then opt into types one at a time. Rename the existing "signed wrap" sanitizer to just the entire topic area: "integer wrap". Enable the implicit integer truncation sanitizers, with required callbacks and tests. Notably, this requires features (currently) only available in Clang, so we can depend on the cc-option tests to determine availability instead of doing version tests. Link: https://lore.kernel.org/r/20250307041914.937329-1-kees@kernel.org Signed-off-by: Kees Cook <kees@kernel.org>
2025-03-03compiler.h: Introduce __must_be_noncstr()Kees Cook
In preparation for adding more type checking to the memtostr/strtomem*() helpers, introduce the ability to check for the "nonstring" attribute. This is the reverse of what was added to strscpy*() in commit 559048d156ff ("string: Check for "nonstring" attribute on strscpy() arguments"). Note that __annotated() must be explicitly tested for, as GCC added __builtin_has_attribute() after it added the "nonstring" attribute. Do so here to avoid the !__annotated() test triggering build failures when __builtin_has_attribute() was missing but __nonstring was defined. (I've opted to squash this fix into this patch so we don't end up with a possible bisection target that would leave the kernel unbuildable.) Reported-by: Venkat Rao Bagalkote <venkat88@linux.vnet.ibm.com> Reported-by: Stephen Rothwell <sfr@canb.auug.org.au> Reported-by: Christophe Leroy <christophe.leroy@csgroup.eu> Reported-by: Michael Kelley <mhklinux@outlook.com> Closes: https://lore.kernel.org/all/adbe8dd1-a725-4811-ae7e-76fe770cf096@linux.vnet.ibm.com/ Tested-by: Michael Kelley <mhklinux@outlook.com> Signed-off-by: Kees Cook <kees@kernel.org>
2024-11-25Merge tag 'hardening-v6.13-rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux Pull hardening updates from Kees Cook: - Disable __counted_by in Clang < 19.1.3 (Jan Hendrik Farr) - string_helpers: Silence output truncation warning (Bartosz Golaszewski) - compiler.h: Avoid needing BUILD_BUG_ON_ZERO() (Philipp Reisner) - MAINTAINERS: Add kernel hardening keywords __counted_by{_le|_be} (Thorsten Blum) * tag 'hardening-v6.13-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux: Compiler Attributes: disable __counted_by for clang < 19.1.3 compiler.h: Fix undefined BUILD_BUG_ON_ZERO() lib: string_helpers: silence snprintf() output truncation warning MAINTAINERS: Add kernel hardening keywords __counted_by{_le|_be}
2024-11-19Compiler Attributes: disable __counted_by for clang < 19.1.3Jan Hendrik Farr
This patch disables __counted_by for clang versions < 19.1.3 because of the two issues listed below. It does this by introducing CONFIG_CC_HAS_COUNTED_BY. 1. clang < 19.1.2 has a bug that can lead to __bdos returning 0: https://github.com/llvm/llvm-project/pull/110497 2. clang < 19.1.3 has a bug that can lead to __bdos being off by 4: https://github.com/llvm/llvm-project/pull/112636 Fixes: c8248faf3ca2 ("Compiler Attributes: counted_by: Adjust name and identifier expansion") Cc: stable@vger.kernel.org # 6.6.x: 16c31dd7fdf6: Compiler Attributes: counted_by: bump min gcc version Cc: stable@vger.kernel.org # 6.6.x: 2993eb7a8d34: Compiler Attributes: counted_by: fixup clang URL Cc: stable@vger.kernel.org # 6.6.x: 231dc3f0c936: lkdtm/bugs: Improve warning message for compilers without counted_by support Cc: stable@vger.kernel.org # 6.6.x Reported-by: Nathan Chancellor <nathan@kernel.org> Closes: https://lore.kernel.org/all/20240913164630.GA4091534@thelio-3990X/ Reported-by: kernel test robot <oliver.sang@intel.com> Closes: https://lore.kernel.org/oe-lkp/202409260949.a1254989-oliver.sang@intel.com Link: https://lore.kernel.org/all/Zw8iawAF5W2uzGuh@archlinux/T/#m204c09f63c076586a02d194b87dffc7e81b8de7b Suggested-by: Nathan Chancellor <nathan@kernel.org> Signed-off-by: Jan Hendrik Farr <kernel@jfarr.cc> Reviewed-by: Nathan Chancellor <nathan@kernel.org> Tested-by: Nathan Chancellor <nathan@kernel.org> Reviewed-by: Miguel Ojeda <ojeda@kernel.org> Reviewed-by: Thorsten Blum <thorsten.blum@linux.dev> Link: https://lore.kernel.org/r/20241029140036.577804-2-kernel@jfarr.cc Signed-off-by: Kees Cook <kees@kernel.org>
2024-11-03compiler_types: Add noinline_for_tracing annotationYafang Shao
Kernel functions that are not inlined can be easily hooked with BPF for tracing. However, functions intended for tracing may still be inlined unexpectedly. For example, in our case, after upgrading the compiler from GCC 9 to GCC 11, the tcp_drop_reason() function was inlined, which broke our monitoring tools. To prevent this, we need to ensure that the function remains non-inlined. The noinline_for_tracing annotation is introduced as a general solution for preventing inlining of kernel functions that need to be traced. This approach avoids the need for adding individual noinline comments to each function and provides a more consistent way to maintain traceability. Link: https://lore.kernel.org/netdev/CANn89iKvr44ipuRYFaPTpzwz=B_+pgA94jsggQ946mjwreV6Aw@mail.gmail.com/ Suggested-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Yafang Shao <laoar.shao@gmail.com> Link: https://patch.msgid.link/20241024093742.87681-2-laoar.shao@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-08-22string: Check for "nonstring" attribute on strscpy() argumentsKees Cook
GCC already checks for arguments that are marked with the "nonstring"[1] attribute when used on standard C String API functions (e.g. strcpy). Gain this compile-time checking also for the kernel's primary string copying function, strscpy(). Note that Clang has neither "nonstring" nor __builtin_has_attribute(). Link: https://gcc.gnu.org/onlinedocs/gcc/Common-Variable-Attributes.html#index-nonstring-variable-attribute [1] Reviewed-by: Miguel Ojeda <ojeda@kernel.org> Tested-by: Miguel Ojeda <ojeda@kernel.org> Link: https://lore.kernel.org/r/20240805214340.work.339-kees@kernel.org Signed-off-by: Kees Cook <kees@kernel.org>
2024-06-14compiler_types.h: Define __retain for __attribute__((__retain__))Tony Ambardar
Some code includes the __used macro to prevent functions and data from being optimized out. This macro implements __attribute__((__used__)), which operates at the compiler and IR-level, and so still allows a linker to remove objects intended to be kept. Compilers supporting __attribute__((__retain__)) can address this gap by setting the flag SHF_GNU_RETAIN on the section of a function/variable, indicating to the linker the object should be retained. This attribute is available since gcc 11, clang 13, and binutils 2.36. Provide a __retain macro implementing __attribute__((__retain__)), whose first user will be the '__bpf_kfunc' tag. [ Additional remark from discussion: Why is CONFIG_LTO_CLANG added here? The __used macro permits garbage collection at section level, so CLANG_LTO_CLANG without CONFIG_LD_DEAD_CODE_DATA_ELIMINATION should not change final section dynamics? The conditional guard was included to ensure consistent behaviour between __retain and other features forcing split sections. In particular, the same guard is used in vmlinux.lds.h to merge split sections where needed. For example, using __retain in LLVM builds without CONFIG_LTO was failing CI tests on kernel-patches/bpf because the kernel didn't boot properly. And in further testing, the kernel had no issues loading BPF kfunc modules with such split sections, so the module (partial) linking scripts were left alone. ] Signed-off-by: Tony Ambardar <tony.ambardar@gmail.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Cc: Yonghong Song <yonghong.song@linux.dev> Link: https://lore.kernel.org/bpf/ZlmGoT9KiYLZd91S@krava/T/ Link: https://lore.kernel.org/bpf/b31bca5a5e6765a0f32cc8c19b1d9cdbfaa822b5.1717477560.git.Tony.Ambardar@gmail.com
2024-05-22Merge local branch 'x86-codegen'Linus Torvalds
Merge trivial x86 code generation annoyances - Introduce helper macros for clang asm input problems - use said macros to improve trivially stupid code generation issues in bitops and array_index_mask_nospec - also improve codegen with 32-bit array index comparisons None of these really matter, but I look at code generation and profiles fairly regularly, and these misfeatures caused the generated code to look really odd and distract from the real issues. * branch 'x86-codegen' of local tree: x86: improve bitop code generation with clang x86: improve array_index_mask_nospec() code generation clang: work around asm input constraint problems
2024-05-22clang: work around asm input constraint problemsLinus Torvalds
Work around clang problems with asm constraints that have multiple possibilities, particularly "g" and "rm". Clang seems to turn inputs like that into the most generic form, which is the memory input - but to make matters worse, clang won't even use a possible original memory location, but will spill the value to stack, and use the stack for the asm input. See https://github.com/llvm/llvm-project/issues/20571#issuecomment-980933442 for some explanation of why clang has this strange behavior, but the end result is that "g" and "rm" really end up generating horrid code. Link: https://github.com/llvm/llvm-project/issues/20571 Cc: Peter Zijlstra <peterz@infradead.org> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2024-05-14Merge tag 'net-next-6.10' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next Pull networking updates from Jakub Kicinski: "Core & protocols: - Complete rework of garbage collection of AF_UNIX sockets. AF_UNIX is prone to forming reference count cycles due to fd passing functionality. New method based on Tarjan's Strongly Connected Components algorithm should be both faster and remove a lot of workarounds we accumulated over the years. - Add TCP fraglist GRO support, allowing chaining multiple TCP packets and forwarding them together. Useful for small switches / routers which lack basic checksum offload in some scenarios (e.g. PPPoE). - Support using SMP threads for handling packet backlog i.e. packet processing from software interfaces and old drivers which don't use NAPI. This helps move the processing out of the softirq jumble. - Continue work of converting from rtnl lock to RCU protection. Don't require rtnl lock when reading: IPv6 routing FIB, IPv6 address labels, netdev threaded NAPI sysfs files, bonding driver's sysfs files, MPLS devconf, IPv4 FIB rules, netns IDs, tcp metrics, TC Qdiscs, neighbor entries, ARP entries via ioctl(SIOCGARP), a lot of the link information available via rtnetlink. - Small optimizations from Eric to UDP wake up handling, memory accounting, RPS/RFS implementation, TCP packet sizing etc. - Allow direct page recycling in the bulk API used by XDP, for +2% PPS. - Support peek with an offset on TCP sockets. - Add MPTCP APIs for querying last time packets were received/sent/acked and whether MPTCP "upgrade" succeeded on a TCP socket. - Add intra-node communication shortcut to improve SMC performance. - Add IPv6 (and IPv{4,6}-over-IPv{4,6}) support to the GTP protocol driver. - Add HSR-SAN (RedBOX) mode of operation to the HSR protocol driver. - Add reset reasons for tracing what caused a TCP reset to be sent. - Introduce direction attribute for xfrm (IPSec) states. State can be used either for input or output packet processing. Things we sprinkled into general kernel code: - Add bitmap_{read,write}(), bitmap_size(), expose BYTES_TO_BITS(). This required touch-ups and renaming of a few existing users. - Add Endian-dependent __counted_by_{le,be} annotations. - Make building selftests "quieter" by printing summaries like "CC object.o" rather than full commands with all the arguments. Netfilter: - Use GFP_KERNEL to clone elements, to deal better with OOM situations and avoid failures in the .commit step. BPF: - Add eBPF JIT for ARCv2 CPUs. - Support attaching kprobe BPF programs through kprobe_multi link in a session mode, meaning, a BPF program is attached to both function entry and return, the entry program can decide if the return program gets executed and the entry program can share u64 cookie value with return program. "Session mode" is a common use-case for tetragon and bpftrace. - Add the ability to specify and retrieve BPF cookie for raw tracepoint programs in order to ease migration from classic to raw tracepoints. - Add an internal-only BPF per-CPU instruction for resolving per-CPU memory addresses and implement support in x86, ARM64 and RISC-V JITs. This allows inlining functions which need to access per-CPU state. - Optimize x86 BPF JIT's emit_mov_imm64, and add support for various atomics in bpf_arena which can be JITed as a single x86 instruction. Support BPF arena on ARM64. - Add a new bpf_wq API for deferring events and refactor process-context bpf_timer code to keep common code where possible. - Harden the BPF verifier's and/or/xor value tracking. - Introduce crypto kfuncs to let BPF programs call kernel crypto APIs. - Support bpf_tail_call_static() helper for BPF programs with GCC 13. - Add bpf_preempt_{disable,enable}() kfuncs in order to allow a BPF program to have code sections where preemption is disabled. Driver API: - Skip software TC processing completely if all installed rules are marked as HW-only, instead of checking the HW-only flag rule by rule. - Add support for configuring PoE (Power over Ethernet), similar to the already existing support for PoDL (Power over Data Line) config. - Initial bits of a queue control API, for now allowing a single queue to be reset without disturbing packet flow to other queues. - Common (ethtool) statistics for hardware timestamping. Tests and tooling: - Remove the need to create a config file to run the net forwarding tests so that a naive "make run_tests" can exercise them. - Define a method of writing tests which require an external endpoint to communicate with (to send/receive data towards the test machine). Add a few such tests. - Create a shared code library for writing Python tests. Expose the YAML Netlink library from tools/ to the tests for easy Netlink access. - Move netfilter tests under net/, extend them, separate performance tests from correctness tests, and iron out issues found by running them "on every commit". - Refactor BPF selftests to use common network helpers. - Further work filling in YAML definitions of Netlink messages for: nftables, team driver, bonding interfaces, vlan interfaces, VF info, TC u32 mark, TC police action. - Teach Python YAML Netlink to decode attribute policies. - Extend the definition of the "indexed array" construct in the specs to cover arrays of scalars rather than just nests. - Add hyperlinks between definitions in generated Netlink docs. Drivers: - Make sure unsupported flower control flags are rejected by drivers, and make more drivers report errors directly to the application rather than dmesg (large number of driver changes from Asbjørn Sloth Tønnesen). - Ethernet high-speed NICs: - Broadcom (bnxt): - support multiple RSS contexts and steering traffic to them - support XDP metadata - make page pool allocations more NUMA aware - Intel (100G, ice, idpf): - extract datapath code common among Intel drivers into a library - use fewer resources in switchdev by sharing queues with the PF - add PFCP filter support - add Ethernet filter support - use a spinlock instead of HW lock in PTP clock ops - support 5 layer Tx scheduler topology - nVidia/Mellanox: - 800G link modes and 100G SerDes speeds - per-queue IRQ coalescing configuration - Marvell Octeon: - support offloading TC packet mark action - Ethernet NICs consumer, embedded and virtual: - stop lying about skb->truesize in USB Ethernet drivers, it messes up TCP memory calculations - Google cloud vNIC: - support changing ring size via ethtool - support ring reset using the queue control API - VirtIO net: - expose flow hash from RSS to XDP - per-queue statistics - add selftests - Synopsys (stmmac): - support controllers which require an RX clock signal from the MII bus to perform their hardware initialization - TI: - icssg_prueth: support ICSSG-based Ethernet on AM65x SR1.0 devices - icssg_prueth: add SW TX / RX Coalescing based on hrtimers - cpsw: minimal XDP support - Renesas (ravb): - support describing the MDIO bus - Realtek (r8169): - add support for RTL8168M - Microchip Sparx5: - matchall and flower actions mirred and redirect - Ethernet switches: - nVidia/Mellanox: - improve events processing performance - Marvell: - add support for MV88E6250 family internal PHYs - Microchip: - add DCB and DSCP mapping support for KSZ switches - vsc73xx: convert to PHYLINK - Realtek: - rtl8226b/rtl8221b: add C45 instances and SerDes switching - Many driver changes related to PHYLIB and PHYLINK deprecated API cleanup - Ethernet PHYs: - Add a new driver for Airoha EN8811H 2.5 Gigabit PHY. - micrel: lan8814: add support for PPS out and external timestamp trigger - WiFi: - Disable Wireless Extensions (WEXT) in all Wi-Fi 7 devices drivers. Modern devices can only be configured using nl80211. - mac80211/cfg80211 - handle color change per link for WiFi 7 Multi-Link Operation - Intel (iwlwifi): - don't support puncturing in 5 GHz - support monitor mode on passive channels - BZ-W device support - P2P with HE/EHT support - re-add support for firmware API 90 - provide channel survey information for Automatic Channel Selection - MediaTek (mt76): - mt7921 LED control - mt7925 EHT radiotap support - mt7920e PCI support - Qualcomm (ath11k): - P2P support for QCA6390, WCN6855 and QCA2066 - support hibernation - ieee80211-freq-limit Device Tree property support - Qualcomm (ath12k): - refactoring in preparation of multi-link support - suspend and hibernation support - ACPI support - debugfs support, including dfs_simulate_radar support - RealTek: - rtw88: RTL8723CS SDIO device support - rtw89: RTL8922AE Wi-Fi 7 PCI device support - rtw89: complete features of new WiFi 7 chip 8922AE including BT-coexistence and Wake-on-WLAN - rtw89: use BIOS ACPI settings to set TX power and channels - rtl8xxxu: enable Management Frame Protection (MFP) support - Bluetooth: - support for Intel BlazarI and Filmore Peak2 (BE201) - support for MediaTek MT7921S SDIO - initial support for Intel PCIe BT driver - remove HCI_AMP support" * tag 'net-next-6.10' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (1827 commits) selftests: netfilter: fix packetdrill conntrack testcase net: gro: fix napi_gro_cb zeroed alignment Bluetooth: btintel_pcie: Refactor and code cleanup Bluetooth: btintel_pcie: Fix warning reported by sparse Bluetooth: hci_core: Fix not handling hdev->le_num_of_adv_sets=1 Bluetooth: btintel: Fix compiler warning for multi_v7_defconfig config Bluetooth: btintel_pcie: Fix compiler warnings Bluetooth: btintel_pcie: Add *setup* function to download firmware Bluetooth: btintel_pcie: Add support for PCIe transport Bluetooth: btintel: Export few static functions Bluetooth: HCI: Remove HCI_AMP support Bluetooth: L2CAP: Fix div-by-zero in l2cap_le_flowctl_init() Bluetooth: qca: Fix error code in qca_read_fw_build_info() Bluetooth: hci_conn: Use __counted_by() and avoid -Wfamnae warning Bluetooth: btintel: Add support for Filmore Peak2 (BE201) Bluetooth: btintel: Add support for BlazarI LE Create Connection command timeout increased to 20 secs dt-bindings: net: bluetooth: Add MediaTek MT7921S SDIO Bluetooth Bluetooth: compute LE flow credits based on recvbuf space Bluetooth: hci_sync: Use cmd->num_cis instead of magic number ...
2024-05-13Merge tag 'kcsan.2024.05.10a' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu Pull kcsan update from Paul McKenney: "Introduce __data_racy type qualifier This adds a __data_racy type qualifier that enables kernel developers to inform KCSAN that a given variable is a shared variable without needing to mark each and every access. This allows pre-KCSAN code to be correctly (if approximately) instrumented withh very little effort, and also provides people reading the code a clear indication that the variable is in fact shared. In addition, it permits incremental transition to per-access KCSAN marking, so that (for example) a given subsystem can be transitioned one variable at a time, while avoiding large numbers of KCSAN warnings during this transition" * tag 'kcsan.2024.05.10a' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu: kcsan, compiler_types: Introduce __data_racy type qualifier
2024-05-07kcsan, compiler_types: Introduce __data_racy type qualifierMarco Elver
Based on the discussion at [1], it would be helpful to mark certain variables as explicitly "data racy", which would result in KCSAN not reporting data races involving any accesses on such variables. To do that, introduce the __data_racy type qualifier: struct foo { ... int __data_racy bar; ... }; In KCSAN-kernels, __data_racy turns into volatile, which KCSAN already treats specially by considering them "marked". In non-KCSAN kernels the type qualifier turns into no-op. The generated code between KCSAN-instrumented kernels and non-KCSAN kernels is already huge (inserted calls into runtime for every memory access), so the extra generated code (if any) due to volatile for few such __data_racy variables are unlikely to have measurable impact on performance. Link: https://lore.kernel.org/all/CAHk-=wi3iondeh_9V2g3Qz5oHTRjLsOpoy83hb58MVh=nRZe0A@mail.gmail.com/ [1] Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Marco Elver <elver@google.com> Cc: Paul E. McKenney <paulmck@kernel.org> Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2024-05-05kmsan: compiler_types: declare __no_sanitize_or_inlineAlexander Potapenko
It turned out that KMSAN instruments READ_ONCE_NOCHECK(), resulting in false positive reports, because __no_sanitize_or_inline enforced inlining. Properly declare __no_sanitize_or_inline under __SANITIZE_MEMORY__, so that it does not __always_inline the annotated function. Link: https://lkml.kernel.org/r/20240426091622.3846771-1-glider@google.com Fixes: 5de0ce85f5a4 ("kmsan: mark noinstr as __no_sanitize_memory") Signed-off-by: Alexander Potapenko <glider@google.com> Reported-by: syzbot+355c5bb8c1445c871ee8@syzkaller.appspotmail.com Link: https://lkml.kernel.org/r/000000000000826ac1061675b0e3@google.com Cc: <stable@vger.kernel.org> Reviewed-by: Marco Elver <elver@google.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Miguel Ojeda <ojeda@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-03-28compiler_types: add Endianness-dependent __counted_by_{le,be}Alexander Lobakin
Some structures contain flexible arrays at the end and the counter for them, but the counter has explicit Endianness and thus __counted_by() can't be used directly. To increase test coverage for potential problems without breaking anything, introduce __counted_by_{le,be}() defined depending on platform's Endianness to either __counted_by() when applicable or noop otherwise. Maybe it would be a good idea to introduce such attributes on compiler level if possible, but for now let's stop on what we have. Acked-by: Kees Cook <keescook@chromium.org> Acked-by: Gustavo A. R. Silva <gustavoars@kernel.org> Signed-off-by: Alexander Lobakin <aleksander.lobakin@intel.com> Reviewed-by: Przemek Kitszel <przemyslaw.kitszel@intel.com> Link: https://lore.kernel.org/r/20240327142241.1745989-2-aleksander.lobakin@intel.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-03-21Merge tag 'kbuild-v6.9' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild Pull Kbuild updates from Masahiro Yamada: - Generate a list of built DTB files (arch/*/boot/dts/dtbs-list) - Use more threads when building Debian packages in parallel - Fix warnings shown during the RPM kernel package uninstallation - Change OBJECT_FILES_NON_STANDARD_*.o etc. to take a relative path to Makefile - Support GCC's -fmin-function-alignment flag - Fix a null pointer dereference bug in modpost - Add the DTB support to the RPM package - Various fixes and cleanups in Kconfig * tag 'kbuild-v6.9' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (67 commits) kconfig: tests: test dependency after shuffling choices kconfig: tests: add a test for randconfig with dependent choices kconfig: tests: support KCONFIG_SEED for the randconfig runner kbuild: rpm-pkg: add dtb files in kernel rpm kconfig: remove unneeded menu_is_visible() call in conf_write_defconfig() kconfig: check prompt for choice while parsing kconfig: lxdialog: remove unused dialog colors kconfig: lxdialog: fix button color for blackbg theme modpost: fix null pointer dereference kbuild: remove GCC's default -Wpacked-bitfield-compat flag kbuild: unexport abs_srctree and abs_objtree kbuild: Move -Wenum-{compare-conditional,enum-conversion} into W=1 kconfig: remove named choice support kconfig: use linked list in get_symbol_str() to iterate over menus kconfig: link menus to a symbol kbuild: fix inconsistent indentation in top Makefile kbuild: Use -fmin-function-alignment when available alpha: merge two entries for CONFIG_ALPHA_GAMMA alpha: merge two entries for CONFIG_ALPHA_EV4 kbuild: change DTC_FLAGS_<basetarget>.o to take the path relative to $(obj) ...
2024-03-12Merge tag 'hardening-v6.9-rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux Pull hardening updates from Kees Cook: "As is pretty normal for this tree, there are changes all over the place, especially for small fixes, selftest improvements, and improved macro usability. Some header changes ended up landing via this tree as they depended on the string header cleanups. Also, a notable set of changes is the work for the reintroduction of the UBSAN signed integer overflow sanitizer so that we can continue to make improvements on the compiler side to make this sanitizer a more viable future security hardening option. Summary: - string.h and related header cleanups (Tanzir Hasan, Andy Shevchenko) - VMCI memcpy() usage and struct_size() cleanups (Vasiliy Kovalev, Harshit Mogalapalli) - selftests/powerpc: Fix load_unaligned_zeropad build failure (Michael Ellerman) - hardened Kconfig fragment updates (Marco Elver, Lukas Bulwahn) - Handle tail call optimization better in LKDTM (Douglas Anderson) - Use long form types in overflow.h (Andy Shevchenko) - Add flags param to string_get_size() (Andy Shevchenko) - Add Coccinelle script for potential struct_size() use (Jacob Keller) - Fix objtool corner case under KCFI (Josh Poimboeuf) - Drop 13 year old backward compat CAP_SYS_ADMIN check (Jingzi Meng) - Add str_plural() helper (Michal Wajdeczko, Kees Cook) - Ignore relocations in .notes section - Add comments to explain how __is_constexpr() works - Fix m68k stack alignment expectations in stackinit Kunit test - Convert string selftests to KUnit - Add KUnit tests for fortified string functions - Improve reporting during fortified string warnings - Allow non-type arg to type_max() and type_min() - Allow strscpy() to be called with only 2 arguments - Add binary mode to leaking_addresses scanner - Various small cleanups to leaking_addresses scanner - Adding wrapping_*() arithmetic helper - Annotate initial signed integer wrap-around in refcount_t - Add explicit UBSAN section to MAINTAINERS - Fix UBSAN self-test warnings - Simplify UBSAN build via removal of CONFIG_UBSAN_SANITIZE_ALL - Reintroduce UBSAN's signed overflow sanitizer" * tag 'hardening-v6.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux: (51 commits) selftests/powerpc: Fix load_unaligned_zeropad build failure string: Convert helpers selftest to KUnit string: Convert selftest to KUnit sh: Fix build with CONFIG_UBSAN=y compiler.h: Explain how __is_constexpr() works overflow: Allow non-type arg to type_max() and type_min() VMCI: Fix possible memcpy() run-time warning in vmci_datagram_invoke_guest_handler() lib/string_helpers: Add flags param to string_get_size() x86, relocs: Ignore relocations in .notes section objtool: Fix UNWIND_HINT_{SAVE,RESTORE} across basic blocks overflow: Use POD in check_shl_overflow() lib: stackinit: Adjust target string to 8 bytes for m68k sparc: vdso: Disable UBSAN instrumentation kernel.h: Move lib/cmdline.c prototypes to string.h leaking_addresses: Provide mechanism to scan binary files leaking_addresses: Ignore input device status lines leaking_addresses: Use File::Temp for /tmp files MAINTAINERS: Update LEAKING_ADDRESSES details fortify: Improve buffer overflow reporting fortify: Add KUnit tests for runtime overflows ...
2024-02-25kbuild: Use -fmin-function-alignment when availablePetr Pavlu
GCC recently added option -fmin-function-alignment, which should appear in GCC 14. Unlike -falign-functions, this option causes all functions to be aligned at the specified value, including the cold ones. In particular, when an arm64 kernel is built with DYNAMIC_FTRACE_WITH_CALL_OPS=y, the 8-byte function alignment is required for correct functionality. This was done by -falign-functions=8 and having workarounds in the kernel to force the compiler to follow this alignment. The new -fmin-function-alignment option directly guarantees it. Detect availability of -fmin-function-alignment and use it instead of -falign-functions when present. Introduce CC_HAS_SANE_FUNCTION_ALIGNMENT and enable __cold to work as expected when it is set. Signed-off-by: Petr Pavlu <petr.pavlu@suse.com> Reviewed-by: Nathan Chancellor <nathan@kernel.org> Acked-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>