Commit Graph

2636 Commits

Author SHA1 Message Date
Linus Torvalds
f1c538ca81 Merge tag 'timers-vdso-2026-02-09' of 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()
2026-02-10 17:02:23 -08:00
Linus Torvalds
0923fd0419 Merge tag 'locking-core-2026-02-08' of 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
  ...
2026-02-10 12:28:44 -08:00
Linus Torvalds
f17b474e36 Merge tag 'bpf-next-7.0' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next
Pull bpf updates from Alexei Starovoitov:

 - Support associating BPF program with struct_ops (Amery Hung)

 - Switch BPF local storage to rqspinlock and remove recursion detection
   counters which were causing false positives (Amery Hung)

 - Fix live registers marking for indirect jumps (Anton Protopopov)

 - Introduce execution context detection BPF helpers (Changwoo Min)

 - Improve verifier precision for 32bit sign extension pattern
   (Cupertino Miranda)

 - Optimize BTF type lookup by sorting vmlinux BTF and doing binary
   search (Donglin Peng)

 - Allow states pruning for misc/invalid slots in iterator loops (Eduard
   Zingerman)

 - In preparation for ASAN support in BPF arenas teach libbpf to move
   global BPF variables to the end of the region and enable arena kfuncs
   while holding locks (Emil Tsalapatis)

 - Introduce support for implicit arguments in kfuncs and migrate a
   number of them to new API. This is a prerequisite for cgroup
   sub-schedulers in sched-ext (Ihor Solodrai)

 - Fix incorrect copied_seq calculation in sockmap (Jiayuan Chen)

 - Fix ORC stack unwind from kprobe_multi (Jiri Olsa)

 - Speed up fentry attach by using single ftrace direct ops in BPF
   trampolines (Jiri Olsa)

 - Require frozen map for calculating map hash (KP Singh)

 - Fix lock entry creation in TAS fallback in rqspinlock (Kumar
   Kartikeya Dwivedi)

 - Allow user space to select cpu in lookup/update operations on per-cpu
   array and hash maps (Leon Hwang)

 - Make kfuncs return trusted pointers by default (Matt Bobrowski)

 - Introduce "fsession" support where single BPF program is executed
   upon entry and exit from traced kernel function (Menglong Dong)

 - Allow bpf_timer and bpf_wq use in all programs types (Mykyta
   Yatsenko, Andrii Nakryiko, Kumar Kartikeya Dwivedi, Alexei
   Starovoitov)

 - Make KF_TRUSTED_ARGS the default for all kfuncs and clean up their
   definition across the tree (Puranjay Mohan)

 - Allow BPF arena calls from non-sleepable context (Puranjay Mohan)

 - Improve register id comparison logic in the verifier and extend
   linked registers with negative offsets (Puranjay Mohan)

 - In preparation for BPF-OOM introduce kfuncs to access memcg events
   (Roman Gushchin)

 - Use CFI compatible destructor kfunc type (Sami Tolvanen)

 - Add bitwise tracking for BPF_END in the verifier (Tianci Cao)

 - Add range tracking for BPF_DIV and BPF_MOD in the verifier (Yazhou
   Tang)

 - Make BPF selftests work with 64k page size (Yonghong Song)

* tag 'bpf-next-7.0' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (268 commits)
  selftests/bpf: Fix outdated test on storage->smap
  selftests/bpf: Choose another percpu variable in bpf for btf_dump test
  selftests/bpf: Remove test_task_storage_map_stress_lookup
  selftests/bpf: Update task_local_storage/task_storage_nodeadlock test
  selftests/bpf: Update task_local_storage/recursion test
  selftests/bpf: Update sk_storage_omem_uncharge test
  bpf: Switch to bpf_selem_unlink_nofail in bpf_local_storage_{map_free, destroy}
  bpf: Support lockless unlink when freeing map or local storage
  bpf: Prepare for bpf_selem_unlink_nofail()
  bpf: Remove unused percpu counter from bpf_local_storage_map_free
  bpf: Remove cgroup local storage percpu counter
  bpf: Remove task local storage percpu counter
  bpf: Change local_storage->lock and b->lock to rqspinlock
  bpf: Convert bpf_selem_unlink to failable
  bpf: Convert bpf_selem_link_map to failable
  bpf: Convert bpf_selem_unlink_map to failable
  bpf: Select bpf_local_storage_map_bucket based on bpf_local_storage
  selftests/xsk: fix number of Tx frags in invalid packet
  selftests/xsk: properly handle batch ending in the middle of a packet
  bpf: Prevent reentrance into call_rcu_tasks_trace()
  ...
2026-02-10 11:26:21 -08:00
Linus Torvalds
85f24b0ace Merge tag 'hardening-v7.0-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux
Pull hardening updates from Kees Cook:
 "Mostly small cleanups and various scattered annotations and flex array
  warning fixes that we reviewed by unlanded in other trees. Introduces
  new annotation for expanding counted_by to pointer members, now that
  compiler behavior between GCC and Clang has been normalized.

   - Various missed __counted_by annotations (Thorsten Blum)

   - Various missed -Wflex-array-member-not-at-end fixes (Gustavo A. R.
     Silva)

   - Avoid leftover tempfiles for interrupted compile-time FORTIFY tests
     (Nicolas Schier)

   - Remove non-existant CONFIG_UBSAN_REPORT_FULL from docs (Stefan
     Wiehler)

   - fortify: Use C arithmetic not FIELD_xxx() in FORTIFY_REASON defines
     (David Laight)

   - Add __counted_by_ptr attribute, tests, and first user (Bill
     Wendling, Kees Cook)

   - Update MAINTAINERS file to make hardening section not include
     pstore"

* tag 'hardening-v7.0-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
  MAINTAINERS: pstore: Remove L: entry
  nfp: tls: Avoid -Wflex-array-member-not-at-end warnings
  carl9170: Avoid -Wflex-array-member-not-at-end warning
  coredump: Use __counted_by_ptr for struct core_name::corename
  lkdtm/bugs: Add __counted_by_ptr() test PTR_BOUNDS
  compiler_types.h: Attributes: Add __counted_by_ptr macro
  fortify: Cleanup temp file also on non-successful exit
  fortify: Rename temporary file to match ignore pattern
  fortify: Use C arithmetic not FIELD_xxx() in FORTIFY_REASON defines
  ecryptfs: Annotate struct ecryptfs_message with __counted_by
  fs/xattr: Annotate struct simple_xattr with __counted_by
  crypto: af_alg - Annotate struct af_alg_iv with __counted_by
  Kconfig.ubsan: Remove CONFIG_UBSAN_REPORT_FULL from documentation
  drm/nouveau: fifo: Avoid -Wflex-array-member-not-at-end warning
2026-02-10 08:54:13 -08:00
Linus Torvalds
72c395024d Merge tag 'docs-7.0' of git://git.kernel.org/pub/scm/linux/kernel/git/docs/linux
Pull documentation updates from Jonathan Corbet:
 "A slightly calmer cycle for docs this time around, though there is
  still a fair amount going on, including:

   - Some signs of life on the long-moribund Japanese translation

   - Documentation on policies around the use of generative tools for
     patch submissions, and a separate document intended for consumption
     by generative tools

   - The completion of the move of the documentation tools to
     tools/docs. For now we're leaving a /scripts/kernel-doc symlink
     behind to avoid breaking scripts

   - Ongoing build-system work includes the incorporation of
     documentation in Python code, better support for documenting
     variables, and lots of improvements and fixes

   - Automatic linking of man-page references -- cat(1), for example --
     to the online pages in the HTML build

  ...and the usual array of typo fixes and such"

* tag 'docs-7.0' of git://git.kernel.org/pub/scm/linux/kernel/git/docs/linux: (107 commits)
  doc: development-process: add notice on testing
  tools: sphinx-build-wrapper: improve its help message
  docs: sphinx-build-wrapper: allow -v override -q
  docs: kdoc: Fix pdfdocs build for tools
  docs: ja_JP: process: translate 'Obtain a current source tree'
  docs: fix 're-use' -> 'reuse' in documentation
  docs: ioctl-number: fix a typo in ioctl-number.rst
  docs: filesystems: ensure proc pid substitutable is complete
  docs: automarkup.py: Skip common English words as C identifiers
  Documentation: use a source-read extension for the index link boilerplate
  docs: parse_features: make documentation more consistent
  docs: add parse_features module documentation
  docs: jobserver: do some documentation improvements
  docs: add jobserver module documentation
  docs: kabi: helpers: add documentation for each "enum" value
  docs: kabi: helpers: add helper for debug bits 7 and 8
  docs: kabi: system_symbols: end docstring phrases with a dot
  docs: python: abi_regex: do some improvements at documentation
  docs: python: abi_parser: do some improvements at documentation
  docs: add kabi modules documentation
  ...
2026-02-09 20:53:18 -08:00
Linus Torvalds
05f7e89ab9 Linux 6.19 2026-02-08 13:03:27 -08:00
Linus Torvalds
18f7fcd5e6 Linux 6.19-rc8 2026-02-01 14:01:13 -08:00
Linus Torvalds
367b81ef01 Merge tag 'rust-fixes-6.19' of git://git.kernel.org/pub/scm/linux/kernel/git/ojeda/linux
Pull Rust fixes from Miguel Ojeda:
 "Toolchain and infrastructure:

   - Trigger rebuilds of the newly added 'proc-macro2' crate (and its
     dependencies) when the Rust compiler version changes

   - Fix error in '.rsi' targets (macro expanding single targets) under
     'O=' pointing to an external (not subdir) folder

   - Fix off-by-one line number in 'rustdoc' KUnit tests

   - Add '-fdiagnostics-show-context' to GCC flags skipped by 'bindgen'

   - Clean objtool warning by adding one more 'noreturn' function

   - Clean 'libpin_init_internal.{so,dylib}' in 'mrproper'

  'kernel' crate:

   - Fix build error when using expressions in formatting arguments

   - Mark 'num::Bounded::__new()' as unsafe and clean documentation
     accordingly

   - Always inline functions using 'build_assert' with arguments

   - Fix 'rusttest' build error providing the right 'isize_atomic_repr'
     type for the host

  'macros' crate:

   - Fix 'rusttest' build error by ignoring example

  rust-analyzer:

   - Remove assertion that was not true for distributions like NixOS

   - Add missing dependency edges and fix editions for 'quote' and
     sysroot crates to provide correct IDE support

  DRM Tyr:

   - Fix build error by adding missing dependency on 'CONFIG_COMMON_CLK'

  Plus clean a few typos in docs and comments"

* tag 'rust-fixes-6.19' of git://git.kernel.org/pub/scm/linux/kernel/git/ojeda/linux: (28 commits)
  rust: num: bounded: clean __new documentation and comments
  scripts: generate_rust_analyzer: fix resolution of #[pin_data] macros
  drm/tyr: depend on `COMMON_CLK` to fix build error
  rust: sync: atomic: Provide stub for `rusttest` 32-bit hosts
  kbuild: rust: clean libpin_init_internal in mrproper
  rust: proc-macro2: rebuild if the version text changes
  rust: num: bounded: add missing comment for always inlined function
  rust: sync: refcount: always inline functions using build_assert with arguments
  rust: bits: always inline functions using build_assert with arguments
  scripts: generate_rust_analyzer: compile sysroot with correct edition
  scripts: generate_rust_analyzer: compile quote with correct edition
  scripts: generate_rust_analyzer: quote: treat `core` and `std` as dependencies
  scripts: generate_rust_analyzer: syn: treat `std` as a dependency
  scripts: generate_rust_analyzer: remove sysroot assertion
  rust: kbuild: give `--config-path` to `rustfmt` in `.rsi` target
  scripts: generate_rust_analyzer: Add pin_init_internal deps
  scripts: generate_rust_analyzer: Add pin_init -> compiler_builtins dep
  scripts: generate_rust_analyzer: Add compiler_builtins -> core dep
  rust: macros: ignore example with module parameters
  rust: num: bounded: mark __new as unsafe
  ...
2026-01-30 16:15:59 -08:00
Linus Torvalds
63804fed14 Linux 6.19-rc7 2026-01-25 14:11:24 -08:00
Chen Miao
a44bfed9df kbuild: rust: clean libpin_init_internal in mrproper
When I enabled Rust compilation, I wanted to clean up its output, so I
used make mrproper. However, I was still able to find that
libpin_init_internal.so in the rust directory was not deleted, while
all other corresponding outputs were cleared.

Thus add it to the `MRPROPER_FILES` list.

Reviewed-by: Dongliang Mu <dzm91@hust.edu.cn>
Signed-off-by: Chen Miao <chenmiao@openatom.club>
Fixes: d7659acca7 ("rust: add pin-init crate build infrastructure")
Cc: stable@vger.kernel.org
Acked-by: Nicolas Schier <nsc@kernel.org>
Acked-by: Benno Lossin <lossin@kernel.org>
Link: https://patch.msgid.link/71ff222b8731e63e06059c5d8566434e508baf2b.1761876365.git.chenmiao@openatom.club
[ Fixed tags and Git author as discussed. Reworded slightly. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2026-01-23 23:25:00 +01:00
Jonathan Corbet
eba6ffd126 docs: kdoc: move kernel-doc to tools/docs
kernel-doc is the last documentation-related tool still living outside of
the tools/docs directory; the time has come to move it over.

[mchehab: fixed kdoc lib location]

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Message-ID: <311d17e403524349940a8b12de6b5e91e554b1f4.1768823489.git.mchehab+huawei@kernel.org>
2026-01-20 15:31:06 -07:00
Linus Torvalds
24d479d26b Linux 6.19-rc6 2026-01-18 15:42:45 -08:00
Peter Zijlstra
fd69b2f7d5 compiler: Use __typeof_unqual__() for __unqual_scalar_typeof()
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/
2026-01-18 10:32:03 +01:00
Bill Wendling
150a04d817 compiler_types.h: Attributes: Add __counted_by_ptr macro
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>
2026-01-17 11:00:28 -08:00
Alexei Starovoitov
e3d0dbb3b5 Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf after rc5
Cross-merge BPF and other fixes after downstream PR.

No conflicts.

Adjacent:
Auto-merging MAINTAINERS
Auto-merging Makefile
Auto-merging kernel/bpf/verifier.c
Auto-merging kernel/sched/ext.c
Auto-merging mm/memcontrol.c

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2026-01-14 15:22:01 -08:00
Linus Torvalds
0f61b1860c Linux 6.19-rc5 2026-01-11 17:03:14 -10:00
Marco Elver
3269701cb2 compiler-context-analysis: Add infrastructure for Context Analysis with Clang
Context Analysis is a language extension, which enables statically
checking that required contexts are active (or inactive), by acquiring
and releasing user-definable "context locks". An obvious application is
lock-safety checking for the kernel's various synchronization primitives
(each of which represents a "context lock"), and checking that locking
rules are not violated.

Clang originally called the feature "Thread Safety Analysis" [1]. This
was later changed and the feature became more flexible, gaining the
ability to define custom "capabilities". Its foundations can be found in
"Capability Systems" [2], used to specify the permissibility of
operations to depend on some "capability" being held (or not held).

Because the feature is not just able to express "capabilities" related
to synchronization primitives, and "capability" is already overloaded in
the kernel, the naming chosen for the kernel departs from Clang's
"Thread Safety" and "capability" nomenclature; we refer to the feature
as "Context Analysis" to avoid confusion. The internal implementation
still makes references to Clang's terminology in a few places, such as
`-Wthread-safety` being the warning option that also still appears in
diagnostic messages.

 [1] https://clang.llvm.org/docs/ThreadSafetyAnalysis.html
 [2] https://www.cs.cornell.edu/talc/papers/capabilities.pdf

See more details in the kernel-doc documentation added in this and
subsequent changes.

Clang version 22+ is required.

[peterz: disable the thing for __CHECKER__ builds]
Signed-off-by: Marco Elver <elver@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://patch.msgid.link/20251219154418.3592607-3-elver@google.com
2026-01-05 16:43:26 +01:00
Linus Torvalds
9ace4753a5 Linux 6.19-rc4 2026-01-04 14:41:55 -08:00
Linus Torvalds
f8f9c1f4d0 Linux 6.19-rc3 2025-12-28 13:24:26 -08:00
Linus Torvalds
9448598b22 Linux 6.19-rc2 2025-12-21 15:52:04 -08:00
Ihor Solodrai
90e5b38a26 kbuild: Sync kconfig when PAHOLE_VERSION changes
This patch implements kconfig re-sync when the pahole version changes
between builds, similar to how it happens for compiler version change
via CC_VERSION_TEXT.

Define PAHOLE_VERSION in the top-level Makefile and export it for
config builds. Set CONFIG_PAHOLE_VERSION default to the exported
variable.

Kconfig records the PAHOLE_VERSION value in
include/config/auto.conf.cmd [1].

The Makefile includes auto.conf.cmd, so if PAHOLE_VERSION changes
between builds, make detects a dependency change and triggers
syncconfig to update the kconfig [2].

For external module builds, add a warning message in the prepare
target, similar to the existing compiler version mismatch warning.

Note that if pahole is not installed or available, PAHOLE_VERSION is
set to 0 by pahole-version.sh, so the (un)installation of pahole is
treated as a version change.

See previous discussions for context [3].

[1] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/scripts/kconfig/preprocess.c?h=v6.18#n91
[2] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Makefile?h=v6.18#n815
[3] https://lore.kernel.org/bpf/8f946abf-dd88-4fac-8bb4-84fcd8d81cf0@oracle.com/

Signed-off-by: Ihor Solodrai <ihor.solodrai@linux.dev>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Tested-by: Nicolas Schier <nsc@kernel.org>
Tested-by: Alan Maguire <alan.maguire@oracle.com>
Reviewed-by: Nicolas Schier <nsc@kernel.org>
Link: https://lore.kernel.org/bpf/20251219181321.1283664-6-ihor.solodrai@linux.dev
2025-12-19 10:55:40 -08:00
Linus Torvalds
8f0b4cce44 Linux 6.19-rc1 2025-12-14 16:05:07 +12:00
Linus Torvalds
36492b7141 Merge tag 'tracepoints-v6.19' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace
Pull unused tracepoints update from Steven Rostedt:
 "Detect unused tracepoints.

  If a tracepoint is defined but never used (TRACE_EVENT() created but
  no trace_<tracepoint>() called), it can take up to or more than 5K of
  memory each. This can add up as there are around a hundred unused
  tracepoints with various configs. That is 500K of wasted memory.

  Add a make build parameter of "UT=1" to have the build warn if an
  unused tracepoint is detected in the build. This allows detection of
  unused tracepoints to be upstream so that outreachy and the mentoring
  project can have new developers look for fixing them, without having
  these warnings suddenly show up when someone upgrades their kernel.

  When all known unused tracepoints are removed, then the "UT=1" build
  parameter can be removed and unused tracepoints will always warn. This
  will catch new unused tracepoints after the current ones have been
  removed.

  Summary:

   - Separate out elf functions from sorttable.c

     Move out the ELF parsing functions from sorttable.c so that the
     tracing tooling can use it.

   - Add a tracepoint verifier tool to the build process

     If "UT=1" is added to the kernel command line, any unused
     tracepoints will trigger a warning at build time.

   - Do not warn about unused tracepoints for tracepoints that are
     exported

     There are sever cases where a tracepoint is created by the kernel
     and used by modules. Since there's no easy way to detect if these
     are truly unused since the users are in modules, if a tracepoint is
     exported, assume it will eventually be used by a module. Note,
     there's not many exported tracepoints so this should not be a
     problem to ignore them.

   - Have building of modules also detect unused tracepoints

     Do not only check the main vmlinux for unused tracepoints, also
     check modules. If a module is defining a tracepoint it should be
     using it.

   - Add the tracepoint-update program to the ignore file

     The new tracepoint-update program needs to be ignored by git"

* tag 'tracepoints-v6.19' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  scripts: add tracepoint-update to the list of ignores files
  tracing: Add warnings for unused tracepoints for modules
  tracing: Allow tracepoint-update.c to work with modules
  tracepoint: Do not warn for unused event that is exported
  tracing: Add a tracepoint verification check at build time
  sorttable: Move ELF parsing into scripts/elf-parse.[ch]
2025-12-05 09:37:41 -08:00
Linus Torvalds
ed1b409137 Merge tag 'hardening-v6.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux
Pull hardening updates from Kees Cook:

 - string: Add missing kernel-doc return descriptions (Kriish Sharma)

 - Update some mis-typed allocations

   These correct some accidentally wrong types used in allocations (that
   didn't affect the resulting size) that never got picked up from the
   batch I sent a few months ago.

 - Enable GCC diagnostic context for value-tracking warnings

   This results in better GCC diagnostics for the value range tracking,
   so we can get better visibility into where those values are coming
   from when we get out-of-bounds warnings at compile time.

* tag 'hardening-v6.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
  kbuild: Enable GCC diagnostic context for value-tracking warnings
  string: Add missing kernel-doc return descriptions
  media: iris: Cast iris_hfi_gen2_get_instance() allocation type
  drm/plane: Remove const qualifier from plane->modifiers allocation type
  comedi: Adjust range_table_list allocation type
2025-12-05 09:11:02 -08:00
Linus Torvalds
2ddcf4962c Merge tag 'kbuild-6.19-1' of git://git.kernel.org/pub/scm/linux/kernel/git/kbuild/linux
Pull Kbuild updates from Nicolas Schier:

  - Enable -fms-extensions, allowing anonymous use of tagged struct or
    union in struct/union (tag kbuild-ms-extensions-6.19). An exemplary
    conversion patch is added here, too (btrfs).

    [ Editor's note: the core of this actually came in early through a
      shared branch and a few other trees    - Linus ]

  - Introduce architecture-specific CC_CAN_LINK and flags for userprogs

  - Add new packaging target 'modules-cpio-pkg' for building a initramfs
    cpio w/ kmods

  - Handle included .c files in gen_compile_commands

  - Minor kbuild changes:
     - Use objtree for module signing key path, fixing oot kmod signing
     - Improve documentation of KBUILD_BUILD_TIMESTAMP
     - Reuse KBUILD_USERCFLAGS for UAPI, instead of defining twice
     - Rename scripts/Makefile.extrawarn to Makefile.warn
     - Drop obsolete types.h check from headers_check.pl
     - Remove outdated config leak ignore entries

* tag 'kbuild-6.19-1' of git://git.kernel.org/pub/scm/linux/kernel/git/kbuild/linux:
  kbuild: add target to build a cpio containing modules
  initramfs: add gen_init_cpio to hostprogs unconditionally
  kbuild: allow architectures to override CC_CAN_LINK
  init: deduplicate cc-can-link.sh invocations
  kbuild: don't enable CC_CAN_LINK if the dummy program generates warnings
  scripts: headers_install.sh: Remove two outdated config leak ignore entries
  scripts/clang-tools: Handle included .c files in gen_compile_commands
  kbuild: uapi: Drop types.h check from headers_check.pl
  kbuild: Rename Makefile.extrawarn to Makefile.warn
  MAINTAINERS, .mailmap: Update mail address for Nicolas Schier
  kbuild: uapi: reuse KBUILD_USERCFLAGS
  kbuild: doc: improve KBUILD_BUILD_TIMESTAMP documentation
  kbuild: Use objtree for module signing key path
  btrfs: send: make use of -fms-extensions for defining struct fs_path
2025-12-03 14:42:21 -08:00
Linus Torvalds
784faa8eca Merge tag 'rust-6.19' of git://git.kernel.org/pub/scm/linux/kernel/git/ojeda/linux
Pull Rust updates from Miguel Ojeda:
 "Toolchain and infrastructure:

   - Add support for 'syn'.

     Syn is a parsing library for parsing a stream of Rust tokens into a
     syntax tree of Rust source code.

     Currently this library is geared toward use in Rust procedural
     macros, but contains some APIs that may be useful more generally.

     'syn' allows us to greatly simplify writing complex macros such as
     'pin-init' (Benno has already prepared the 'syn'-based version). We
     will use it in the 'macros' crate too.

     'syn' is the most downloaded Rust crate (according to crates.io),
     and it is also used by the Rust compiler itself. While the amount
     of code is substantial, there should not be many updates needed for
     these crates, and even if there are, they should not be too big,
     e.g. +7k -3k lines across the 3 crates in the last year.

     'syn' requires two smaller dependencies: 'quote' and 'proc-macro2'.
     I only modified their code to remove a third dependency
     ('unicode-ident') and to add the SPDX identifiers. The code can be
     easily verified to exactly match upstream with the provided
     scripts.

     They are all licensed under "Apache-2.0 OR MIT", like the other
     vendored 'alloc' crate we had for a while.

     Please see the merge commit with the cover letter for more context.

   - Allow 'unreachable_pub' and 'clippy::disallowed_names' for
     doctests.

     Examples (i.e. doctests) may want to do things like show public
     items and use names such as 'foo'.

     Nevertheless, we still try to keep examples as close to real code
     as possible (this is part of why running Clippy on doctests is
     important for us, e.g. for safety comments, which userspace Rust
     does not support yet but we are stricter).

  'kernel' crate:

   - Replace our custom 'CStr' type with 'core::ffi::CStr'.

     Using the standard library type reduces our custom code footprint,
     and we retain needed custom functionality through an extension
     trait and a new 'fmt!' macro which replaces the previous 'core'
     import.

     This started in 6.17 and continued in 6.18, and we finally land the
     replacement now. This required quite some stamina from Tamir, who
     split the changes in steps to prepare for the flag day change here.

   - Replace 'kernel::c_str!' with C string literals.

     C string literals were added in Rust 1.77, which produce '&CStr's
     (the 'core' one), so now we can write:

         c"hi"

     instead of:

         c_str!("hi")

   - Add 'num' module for numerical features.

     It includes the 'Integer' trait, implemented for all primitive
     integer types.

     It also includes the 'Bounded' integer wrapping type: an integer
     value that requires only the 'N' least significant bits of the
     wrapped type to be encoded:

         // An unsigned 8-bit integer, of which only the 4 LSBs are used.
         let v = Bounded::<u8, 4>:🆕:<15>();
         assert_eq!(v.get(), 15);

     'Bounded' is useful to e.g. enforce guarantees when working with
     bitfields that have an arbitrary number of bits.

     Values can also be constructed from simple non-constant expressions
     or, for more complex ones, validated at runtime.

     'Bounded' also comes with comparison and arithmetic operations
     (with both their backing type and other 'Bounded's with a
     compatible backing type), casts to change the backing type,
     extending/shrinking and infallible/fallible conversions from/to
     primitives as applicable.

   - 'rbtree' module: add immutable cursor ('Cursor').

     It enables to use just an immutable tree reference where
     appropriate. The existing fully-featured mutable cursor is renamed
     to 'CursorMut'.

  kallsyms:

   - Fix wrong "big" kernel symbol type read from procfs.

  'pin-init' crate:

   - A couple minor fixes (Benno asked me to pick these patches up for
     him this cycle).

  Documentation:

   - Quick Start guide: add Debian 13 (Trixie).

     Debian Stable is now able to build Linux, since Debian 13 (released
     2025-08-09) packages Rust 1.85.0, which is recent enough.

     We are planning to propose that the minimum supported Rust version
     in Linux follows Debian Stable releases, with Debian 13 being the
     first one we upgrade to, i.e. Rust 1.85.

  MAINTAINERS:

   - Add entry for the new 'num' module.

   - Remove Alex as Rust maintainer: he hasn't had the time to
     contribute for a few years now, so it is a no-op change in
     practice.

  And a few other cleanups and improvements"

* tag 'rust-6.19' of git://git.kernel.org/pub/scm/linux/kernel/git/ojeda/linux: (53 commits)
  rust: macros: support `proc-macro2`, `quote` and `syn`
  rust: syn: enable support in kbuild
  rust: syn: add `README.md`
  rust: syn: remove `unicode-ident` dependency
  rust: syn: add SPDX License Identifiers
  rust: syn: import crate
  rust: quote: enable support in kbuild
  rust: quote: add `README.md`
  rust: quote: add SPDX License Identifiers
  rust: quote: import crate
  rust: proc-macro2: enable support in kbuild
  rust: proc-macro2: add `README.md`
  rust: proc-macro2: remove `unicode_ident` dependency
  rust: proc-macro2: add SPDX License Identifiers
  rust: proc-macro2: import crate
  rust: kbuild: support using libraries in `rustc_procmacro`
  rust: kbuild: support skipping flags in `rustc_test_library`
  rust: kbuild: add proc macro library support
  rust: kbuild: simplify `--cfg` handling
  rust: kbuild: introduce `core-flags` and `core-skip_flags`
  ...
2025-12-03 14:16:49 -08:00
Linus Torvalds
f96163865a Merge tag 'docs-6.19' of git://git.lwn.net/linux
Pull documentation updates from Jonathan Corbet:
 "This has been another busy cycle for documentation, with a lot of
  build-system thrashing. That work should slow down from here on out.

   - The various scripts and tools for documentation were spread out in
     several directories; now they are (almost) all coalesced under
     tools/docs/. The holdout is the kernel-doc script, which cannot be
     easily moved without some further thought.

   - As the amount of Python code increases, we are accumulating modules
     that are imported by multiple programs. These modules have been
     pulled together under tools/lib/python/ -- at least, for
     documentation-related programs. There is other Python code in the
     tree that might eventually want to move toward this organization.

   - The Perl kernel-doc.pl script has been removed. It is no longer
     used by default, and nobody has missed it, least of all anybody who
     actually had to look at it.

   - The docs build was controlled by a complex mess of makefilese that
     few dared to touch. Mauro has moved that logic into a new program
     (tools/docs/sphinx-build-wrapper) that, with any luck at all, will
     be far easier to understand and maintain.

   - The get_feat.pl program, used to access information under
     Documentation/features/, has been rewritten in Python, bringing an
     end to the use of Perl in the docs subsystem.

   - The top-level README file has been reorganized into a more
     reader-friendly presentation.

   - A lot of Chinese translation additions

   - Typo fixes and documentation updates as usual"

* tag 'docs-6.19' of git://git.lwn.net/linux: (164 commits)
  docs: makefile: move rustdoc check to the build wrapper
  README: restructure with role-based documentation and guidelines
  docs: kdoc: various fixes for grammar, spelling, punctuation
  docs: kdoc_parser: use '@' for Excess enum value
  docs: submitting-patches: Clarify that removal of Acks needs explanation too
  docs: kdoc_parser: add data/function attributes to ignore
  docs: MAINTAINERS: update Mauro's files/paths
  docs/zh_CN: Add wd719x.rst translation
  docs/zh_CN: Add libsas.rst translation
  get_feat.pl: remove it, as it got replaced by get_feat.py
  Documentation/sphinx/kernel_feat.py: use class directly
  tools/docs/get_feat.py: convert get_feat.pl to Python
  Documentation/admin-guide: fix typo and comment in cscope example
  docs/zh_CN: Add data-integrity.rst translation
  docs/zh_CN: Add blk-mq.rst translation
  docs/zh_CN: Add block/index.rst translation
  docs/zh_CN: Update the Chinese translation of kbuild.rst
  docs: bring some order to our Python module hierarchy
  docs: Move the python libraries to tools/lib/python
  Documentation/kernel-parameters: Move the kernel build options
  ...
2025-12-03 11:34:28 -08:00
Linus Torvalds
b04b2e7a61 Merge tag 'vfs-6.19-rc1.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs
Pull misc vfs updates from Christian Brauner:
 "Features:

   - Cheaper MAY_EXEC handling for path lookup. This elides MAY_WRITE
     permission checks during path lookup and adds the
     IOP_FASTPERM_MAY_EXEC flag so filesystems like btrfs can avoid
     expensive permission work.

   - Hide dentry_cache behind runtime const machinery.

   - Add German Maglione as virtiofs co-maintainer.

  Cleanups:

   - Tidy up and inline step_into() and walk_component() for improved
     code generation.

   - Re-enable IOCB_NOWAIT writes to files. This refactors file
     timestamp update logic, fixing a layering bypass in btrfs when
     updating timestamps on device files and improving FMODE_NOCMTIME
     handling in VFS now that nfsd started using it.

   - Path lookup optimizations extracting slowpaths into dedicated
     routines and adding branch prediction hints for mntput_no_expire(),
     fd_install(), lookup_slow(), and various other hot paths.

   - Enable clang's -fms-extensions flag, requiring a JFS rename to
     avoid conflicts.

   - Remove spurious exports in fs/file_attr.c.

   - Stop duplicating union pipe_index declaration. This depends on the
     shared kbuild branch that brings in -fms-extensions support which
     is merged into this branch.

   - Use MD5 library instead of crypto_shash in ecryptfs.

   - Use largest_zero_folio() in iomap_dio_zero().

   - Replace simple_strtol/strtoul with kstrtoint/kstrtouint in init and
     initrd code.

   - Various typo fixes.

  Fixes:

   - Fix emergency sync for btrfs. Btrfs requires an explicit sync_fs()
     call with wait == 1 to commit super blocks. The emergency sync path
     never passed this, leaving btrfs data uncommitted during emergency
     sync.

   - Use local kmap in watch_queue's post_one_notification().

   - Add hint prints in sb_set_blocksize() for LBS dependency on THP"

* tag 'vfs-6.19-rc1.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: (35 commits)
  MAINTAINERS: add German Maglione as virtiofs co-maintainer
  fs: inline step_into() and walk_component()
  fs: tidy up step_into() & friends before inlining
  orangefs: use inode_update_timestamps directly
  btrfs: fix the comment on btrfs_update_time
  btrfs: use vfs_utimes to update file timestamps
  fs: export vfs_utimes
  fs: lift the FMODE_NOCMTIME check into file_update_time_flags
  fs: refactor file timestamp update logic
  include/linux/fs.h: trivial fix: regualr -> regular
  fs/splice.c: trivial fix: pipes -> pipe's
  fs: mark lookup_slow() as noinline
  fs: add predicts based on nd->depth
  fs: move mntput_no_expire() slowpath into a dedicated routine
  fs: remove spurious exports in fs/file_attr.c
  watch_queue: Use local kmap in post_one_notification()
  fs: touch up predicts in path lookup
  fs: move fd_install() slowpath into a dedicated routine and provide commentary
  fs: hide dentry_cache behind runtime const machinery
  fs: touch predicts in do_dentry_open()
  ...
2025-12-01 08:44:26 -08:00
Linus Torvalds
7d0a66e4bb Linux 6.18 2025-11-30 14:42:10 -08:00
Kees Cook
7454048db2 kbuild: Enable GCC diagnostic context for value-tracking warnings
Enable GCC 16's coming "-fdiagnostics-show-context=N" option[1] to
provide enhanced diagnostic information for value-tracking warnings,
which displays the control flow chain leading to the diagnostic. This
covers our existing use of -Wrestrict and -Wstringop-overread, and
gets us closer to enabling -Warray-bounds, -Wstringop-overflow, and
-Wstringop-truncation, so we can track the rationale for the warning,
letting us more quickly identify actual issues vs what have looked in
the past like false positives. Fixes based on this work have already
been landing, e.g.:

  4a6f18f286 ("net/mlx4_core: Avoid impossible mlx4_db_alloc() order value")
  8a39f1c870 ("ovl: Check for NULL d_inode() in ovl_dentry_upper()")
  e5f7e4e0a4 ("drm/amdgpu/atom: Work around vbios NULL offset false positive")

The context depth ("=N") provides the immediate decision path that led
to the problematic code location, showing conditional checks and branch
decisions that caused the warning. This will help us understand why
GCC's value-tracking analysis triggered the warning and makes it easier
to determine whether warnings are legitimate issues or false positives.

For example, an array bounds warning will now show the conditional
statements (like "if (i >= 4)") that established the out-of-bounds access
range, directly connecting the control flow to the warning location.
This is particularly valuable when GCC's interprocedural analysis can
generate warnings that are difficult to understand without seeing the
inferred control flow.

While my testing has shown that "=1" reports enough for finding
the origin of most bounds issues, I have used "=2" here just to be
conservative. Build time measurements with this option off, =1, and =2
are all with noise of each other, so there seems to be no harm in "turning
it up". If we need to, we can make this value configurable in the future.

Link: https://gcc.gnu.org/git/?p=gcc.git;a=commit;h=6faa3cfe60ff9769d1bebfffdd2c7325217d7389 [1]
Reviewed-by: Miguel Ojeda <ojeda@kernel.org>
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
Link: https://patch.msgid.link/20251121184342.it.626-kees@kernel.org
Signed-off-by: Kees Cook <kees@kernel.org>
2025-11-24 12:44:05 -08:00
Miguel Ojeda
737401751a rust: syn: enable support in kbuild
With all the new files in place and ready from the new crate, enable
the support for it in the build system.

Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Gary Guo <gary@garyguo.net>
Tested-by: Gary Guo <gary@garyguo.net>
Tested-by: Jesung Yang <y.j3ms.n@gmail.com>
Link: https://patch.msgid.link/20251124151837.2184382-20-ojeda@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2025-11-24 17:15:48 +01:00
Miguel Ojeda
88de91cc1c rust: quote: enable support in kbuild
With all the new files in place and ready from the new crate, enable
the support for it in the build system.

Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Gary Guo <gary@garyguo.net>
Tested-by: Gary Guo <gary@garyguo.net>
Tested-by: Jesung Yang <y.j3ms.n@gmail.com>
Link: https://patch.msgid.link/20251124151837.2184382-15-ojeda@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2025-11-24 17:15:43 +01:00
Miguel Ojeda
158a3b7211 rust: proc-macro2: enable support in kbuild
With all the new files in place and ready from the new crate, enable
the support for it in the build system.

`proc_macro_byte_character` and `proc_macro_c_str_literals` were
stabilized in Rust 1.79.0 [1] and were implemented earlier than our
minimum Rust version (1.78) [2][3]. Thus just enable them instead of using
the `cfg` that `proc-macro2` uses to emulate them in older compilers.

In addition, skip formatting for this vendored crate and take the chance
to add a comment mentioning this.

Link: https://github.com/rust-lang/rust/pull/123431 [1]
Link: https://github.com/rust-lang/rust/pull/112711 [2]
Link: https://github.com/rust-lang/rust/pull/119651 [3]
Reviewed-by: Gary Guo <gary@garyguo.net>
Tested-by: Gary Guo <gary@garyguo.net>
Tested-by: Jesung Yang <y.j3ms.n@gmail.com>
Link: https://patch.msgid.link/20251124151837.2184382-11-ojeda@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2025-11-24 17:15:41 +01:00
Linus Torvalds
ac3fd01e4c Linux 6.18-rc7 2025-11-23 14:53:16 -08:00
Linus Torvalds
6a23ae0a96 Linux 6.18-rc6 2025-11-16 14:25:38 -08:00
Thomas Weißschuh
deab487e0f kbuild: allow architectures to override CC_CAN_LINK
The generic test for CC_CAN_LINK assumes that all architectures use -m32
and -m64 to switch between 32-bit and 64-bit compilation. This is overly
simplistic. Architectures may use other flags (-mabi, -m31, etc.) or may
also require byte order handling (-mlittle-endian, -EL). Expressing all
of the different possibilities will be very complicated and brittle.
Instead allow architectures to supply their own logic which will be
easy to understand and evolve.

Both the boolean ARCH_HAS_CC_CAN_LINK and the string ARCH_USERFLAGS need
to be implemented as kconfig does not allow the reuse of string options.

Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
Reviewed-by: Nicolas Schier <nsc@kernel.org>
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
Link: https://patch.msgid.link/20251114-kbuild-userprogs-bits-v3-3-4dee0d74d439@linutronix.de
Signed-off-by: Nicolas Schier <nsc@kernel.org>
2025-11-14 20:20:35 +01:00
Christian Brauner
3c60b0b1e5 Merge patch "kbuild: Add '-fms-extensions' to areas with dedicated CFLAGS"
Nathan Chancellor <nathan@kernel.org> says:

Shared branch between Kbuild and other trees for enabling
'-fms-extensions' for 6.19.

* tag 'kbuild-ms-extensions-6.19' of ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/kbuild/linux:
  kbuild: Add '-fms-extensions' to areas with dedicated CFLAGS
  Kbuild: enable -fms-extensions
  jfs: Rename _inline to avoid conflict with clang's '-fms-extensions'

Link: https://patch.msgid.link/20251101-kbuild-ms-extensions-dedicated-cflags-v1-1-38004aba524b@kernel.org
Signed-off-by: Christian Brauner <brauner@kernel.org>
2025-11-10 10:38:07 +01:00
Linus Torvalds
e9a6fb0bcd Linux 6.18-rc5 2025-11-09 15:10:19 -08:00
Nathan Chancellor
7319256dda kbuild: Rename Makefile.extrawarn to Makefile.warn
Since commit e88ca24319 ("kbuild: consolidate warning flags in
scripts/Makefile.extrawarn"), scripts/Makefile.extrawarn contains all
warnings for the main kernel build, not just warnings enabled by the
values for W=. Rename it to scripts/Makefile.warn to make it clearer
that this Makefile is where all Kbuild warning handling should exist.

Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Link: https://patch.msgid.link/20251023-rename-scripts-makefile-extrawarn-v1-1-8f7531542169@kernel.org
Signed-off-by: Nicolas Schier <nsc@kernel.org>
2025-11-08 12:17:59 +01:00
Nicolas Schier
9716818d61 Merge tag 'kbuild-ms-extensions-6.19' into kbuild-next
Shared branch between Kbuild and other trees for enabling '-fms-extensions' for 6.19

Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Nicolas Schier <nsc@kernel.org>
2025-11-08 12:16:41 +01:00
Linus Torvalds
6146a0f1df Linux 6.18-rc4 2025-11-02 11:28:02 -08:00
Rasmus Villemoes
c4781dc3d1 Kbuild: enable -fms-extensions
Once in a while, it turns out that enabling -fms-extensions could
allow some slightly prettier code. But every time it has come up, the
code that had to be used instead has been deemed "not too awful" and
not worth introducing another compiler flag for.

That's probably true for each individual case, but then it's somewhat
of a chicken/egg situation.

If we just "bite the bullet" as Linus says and enable it once and for
all, it is available whenever a use case turns up, and no individual
case has to justify it.

A lore.kernel.org search provides these examples:

- https://lore.kernel.org/lkml/200706301813.58435.agruen@suse.de/
- https://lore.kernel.org/lkml/20180419152817.GD25406@bombadil.infradead.org/
- https://lore.kernel.org/lkml/170622208395.21664.2510213291504081000@noble.neil.brown.name/
- https://lore.kernel.org/lkml/87h6475w9q.fsf@prevas.dk/
- https://lore.kernel.org/lkml/CAHk-=wjeZwww6Zswn6F_iZTpUihTSNKYppLqj36iQDDhfntuEw@mail.gmail.com/

Undoubtedly, there are more places in the code where this could also
be used but where -fms-extensions just didn't come up in any
discussion.

Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Acked-by: David Sterba <dsterba@suse.com>
Link: https://patch.msgid.link/20251020142228.1819871-2-linux@rasmusvillemoes.dk
[nathan: Move disabled clang warning to scripts/Makefile.extrawarn and
         adjust comment]
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
2025-10-29 16:23:47 -07:00
Linus Torvalds
dcb6fa37fd Linux 6.18-rc3 2025-10-26 15:59:49 -07:00
Steven Rostedt
e30f8e61e2 tracing: Add a tracepoint verification check at build time
If a tracepoint is defined via DECLARE_TRACE() or TRACE_EVENT() but never
called (via the trace_<tracepoint>() function), its metadata is still
around in memory and not discarded.

When created via TRACE_EVENT() the situation is worse because the
TRACE_EVENT() creates metadata that can be around 5k per trace event.
Having unused trace events causes several thousand of wasted bytes.

Add a verifier that injects a string of the name of the tracepoint it
calls that is added to the discarded section "__tracepoint_check".
For every builtin tracepoint, its name (which is saved in the in-memory
section "__tracepoint_strings") will have its name also in the
"__tracepoint_check" section if it is used.

Add a new program that is run on build called tracepoint-update. This is
executed on the vmlinux.o before the __tracepoint_check section is
discarded (the section is discarded before vmlinux is created). This
program will create an array of each string in the __tracepoint_check
section and then sort it. Then it will walk the strings in the
__tracepoint_strings section and do a binary search to check if its name
is in the __tracepoint_check section. If it is not, then it is unused and
a warning is printed.

Note, this currently only handles tracepoints that are builtin and not in
modules.

Enabling this currently with a given config produces:

warning: tracepoint 'sched_move_numa' is unused.
warning: tracepoint 'sched_stick_numa' is unused.
warning: tracepoint 'sched_swap_numa' is unused.
warning: tracepoint 'pelt_hw_tp' is unused.
warning: tracepoint 'pelt_irq_tp' is unused.
warning: tracepoint 'rcu_preempt_task' is unused.
warning: tracepoint 'rcu_unlock_preempted_task' is unused.
warning: tracepoint 'xdp_bulk_tx' is unused.
warning: tracepoint 'xdp_redirect_map' is unused.
warning: tracepoint 'xdp_redirect_map_err' is unused.
warning: tracepoint 'vma_mas_szero' is unused.
warning: tracepoint 'vma_store' is unused.
warning: tracepoint 'hugepage_set_pmd' is unused.
warning: tracepoint 'hugepage_set_pud' is unused.
warning: tracepoint 'hugepage_update_pmd' is unused.
warning: tracepoint 'hugepage_update_pud' is unused.
warning: tracepoint 'block_rq_remap' is unused.
warning: tracepoint 'xhci_dbc_handle_event' is unused.
warning: tracepoint 'xhci_dbc_handle_transfer' is unused.
warning: tracepoint 'xhci_dbc_gadget_ep_queue' is unused.
warning: tracepoint 'xhci_dbc_alloc_request' is unused.
warning: tracepoint 'xhci_dbc_free_request' is unused.
warning: tracepoint 'xhci_dbc_queue_request' is unused.
warning: tracepoint 'xhci_dbc_giveback_request' is unused.
warning: tracepoint 'tcp_ao_wrong_maclen' is unused.
warning: tracepoint 'tcp_ao_mismatch' is unused.
warning: tracepoint 'tcp_ao_key_not_found' is unused.
warning: tracepoint 'tcp_ao_rnext_request' is unused.
warning: tracepoint 'tcp_ao_synack_no_key' is unused.
warning: tracepoint 'tcp_ao_snd_sne_update' is unused.
warning: tracepoint 'tcp_ao_rcv_sne_update' is unused.

Some of the above is totally unused but others are not used due to their
"trace_" functions being inside configs, in which case, the defined
tracepoints should also be inside those same configs. Others are
architecture specific but defined in generic code, where they should
either be moved to the architecture or be surrounded by #ifdef for the
architectures they are for.

This tool could be updated to process modules in the future.

I'd like to thank Mathieu Desnoyers for suggesting using strings instead
of pointers, as using pointers in vmlinux.o required handling relocations
and it required implementing almost a full feature linker to do so.

To enable this check, run the build with: make UT=1

Note, when all the existing unused tracepoints are removed from the build,
the "UT=1" will be removed and this will always be enabled when
tracepoints are configured to warn on any new tracepoints. The reason this
isn't always enabled now is because it will introduce a lot of warnings
for the current unused tracepoints, and all bisects would end at this
commit for those warnings.

Link: https://lore.kernel.org/all/20250528114549.4d8a5e03@gandalf.local.home/

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Masahiro Yamada <masahiroy@kernel.org>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Nicolas Schier <nicolas.schier@linux.dev>
Cc: Nick Desaulniers <nick.desaulniers+lkml@gmail.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Link: https://lore.kernel.org/20251022004452.920728129@kernel.org
Suggested-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> # for using strings instead of pointers
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2025-10-24 16:43:14 -04:00
Linus Torvalds
211ddde082 Linux 6.18-rc2 2025-10-19 15:19:16 -10:00
Jonathan Corbet
3df5affb4b Merge branch 'build-script' into docs-mw
Quoth Mauro:

This series should probably be called:

    "Move the trick-or-treat build hacks accumulated over time
     into a single place and document them."

as this reflects its main goal. As such:

- it places the jobserver logic on a library;
- it removes sphinx/parallel-wrapper.sh;
- the code now properly implements a jobserver-aware logic
  to do the parallelism when called via GNU make, failing back to
  "-j" when there's  no jobserver;
- converts check-variable-fonts.sh to Python and uses it via
  function call;
- drops an extra script to generate man pages, adding a makefile
  target for it;
- ensures that return code is 0 when PDF successfully builds;
- about half of the script is comments and documentation.

I tried to do my best to document all tricks that are inside the
script. This way, the docs build steps is now documented.

It should be noticed that it is out of the scope of this series
to change the implementation. Surely the process can be improved,
but first let's consolidate and document everything on a single
place.

Such script was written in a way that it can be called either
directly or via a Makefile. Running outside Makefile is
interesting specially when debug is needed. The command line
interface replaces the need of having lots of env vars before
calling sphinx-build:

    $ ./tools/docs/sphinx-build-wrapper --help
    usage: sphinx-build-wrapper [-h]
	   [--sphinxdirs SPHINXDIRS [SPHINXDIRS ...]] [--conf CONF]
	   [--builddir BUILDDIR] [--theme THEME] [--css CSS] [--paper {,a4,letter}] [-v]
	   [-j JOBS] [-i] [-V [VENV]]
	   {cleandocs,linkcheckdocs,htmldocs,epubdocs,texinfodocs,infodocs,mandocs,latexdocs,pdfdocs,xmldocs}

    Kernel documentation builder

    positional arguments:
      {cleandocs,linkcheckdocs,htmldocs,epubdocs,texinfodocs,infodocs,mandocs,latexdocs,pdfdocs,xmldocs}
			    Documentation target to build

    options:
      -h, --help            show this help message and exit
      --sphinxdirs SPHINXDIRS [SPHINXDIRS ...]
			    Specific directories to build
      --conf CONF           Sphinx configuration file
      --builddir BUILDDIR   Sphinx configuration file
      --theme THEME         Sphinx theme to use
      --css CSS             Custom CSS file for HTML/EPUB
      --paper {,a4,letter}  Paper size for LaTeX/PDF output
      -v, --verbose         place build in verbose mode
      -j, --jobs JOBS       Sets number of jobs to use with sphinx-build
      -i, --interactive     Change latex default to run in interactive mode
      -V, --venv [VENV]     If used, run Sphinx from a venv dir (default dir: sphinx_latest)

the only mandatory argument is the target, which is identical with
"make" targets.

The call inside Makefile doesn't use the last four arguments. They're
there to help identifying problems at the build:

    -v makes the output verbose;
    -j helps to test parallelism;
    -i runs latexmk in interactive mode, allowing to debug PDF
       build issues;
    -V is useful when testing it with different venvs.

When used with GNU make (or some other make which implements jobserver),
a call like:

    make -j <targets> htmldocs

will make the wrapper to automatically use POSIX jobserver to claim
the number of available job slots, calling sphinx-build with a
"-j" parameter reflecting it. ON such case, the default can be
overriden via SPHINXDIRS argument.

Visiable changes when compared with the old behavior:

When V=0, the only visible difference is that:
- pdfdocs target now returns 0 on success, 1 on failures.
  This addresses an issue over the current process where we
  it always return success even on failures;
- it will now print the name of PDF files that failed to build,
  if any.

In verbose mode, sphinx-build-wrapper and sphinx-build command lines
are now displayed.
2025-10-17 14:11:30 -06:00
Linus Torvalds
3a86608788 Linux 6.18-rc1 2025-10-12 13:42:36 -07:00
Linus Torvalds
ee2fe81cdc Merge tag 'docs-6.18' of git://git.lwn.net/linux
Pull documentation updates from Jonathan Corbet:
 "It has been a relatively busy cycle in docsland, with changes all
  over:

   - Bring the kernel memory-model docs into the Sphinx build in the
     "literal include" mode.

   - Lots of build-infrastructure work, further cleaning up long-term
     kernel-doc technical debt. The sphinx-pre-install tool has been
     converted to Python and updated for current systems.

   - A new tool to detect when documents have been moved and generate
     HTML redirects; this can be used on kernel.org (or any other site
     hosting the rendered docs) to avoid breaking links.

   - Automated processing of the YAML files describing the netlink
     protocol.

   - A significant update of the maintainer's PGP guide.

  ... and a seemingly endless series of typo fixes, build-problem fixes,
  etc"

* tag 'docs-6.18' of git://git.lwn.net/linux: (193 commits)
  Documentation/features: Update feature lists for 6.17-rc7
  docs: remove cdomain.py
  Documentation/process: submitting-patches: fix typo in "were do"
  docs: dev-tools/lkmm: Fix typo of missing file extension
  Documentation: trace: histogram: Convert ftrace docs cross-reference
  Documentation: trace: histogram-design: Wrap introductory note in note:: directive
  Documentation: trace: historgram-design: Separate sched_waking histogram section heading and the following diagram
  Documentation: trace: histogram-design: Trim trailing vertices in diagram explanation text
  Documentation: trace: histogram: Fix histogram trigger subsection number order
  docs: driver-api: fix spelling of "buses".
  Documentation: fbcon: Use admonition directives
  Documentation: fbcon: Reindent 8th step of attach/detach/unload
  Documentation: fbcon: Add boot options and attach/detach/unload section headings
  docs: filesystems: sysfs: add remaining top level sysfs directory descriptions
  docs: filesystems: sysfs: clarify symlink destinations in dev and bus/devices descriptions
  docs: filesystems: sysfs: remove top level sysfs net directory
  docs: maintainer: Fix ambiguous subheading formatting
  docs: kdoc: a few more dump_typedef() tweaks
  docs: kdoc: remove redundant comment stripping in dump_typedef()
  docs: kdoc: remove some dead code in dump_typedef()
  ...
2025-10-03 17:16:13 -07:00
Linus Torvalds
7f70725741 Merge tag 'kbuild-6.18-1' of git://git.kernel.org/pub/scm/linux/kernel/git/kbuild/linux
Pull Kbuild updates from Nathan Chancellor:

 - Extend modules.builtin.modinfo to include module aliases from
   MODULE_DEVICE_TABLE for builtin modules so that userspace tools (such
   as kmod) can verify that a particular module alias will be handled by
   a builtin module

 - Bump the minimum version of LLVM for building the kernel to 15.0.0

 - Upgrade several userspace API checks in headers_check.pl to errors

 - Unify and consolidate CONFIG_WERROR / W=e handling

 - Turn assembler and linker warnings into errors with CONFIG_WERROR /
   W=e

 - Respect CONFIG_WERROR / W=e when building userspace programs
   (userprogs)

 - Enable -Werror unconditionally when building host programs
   (hostprogs)

 - Support copy_file_range() and data segment alignment in gen_init_cpio
   to improve performance on filesystems that support reflinks such as
   btrfs and XFS

 - Miscellaneous small changes to scripts and configuration files

* tag 'kbuild-6.18-1' of git://git.kernel.org/pub/scm/linux/kernel/git/kbuild/linux: (47 commits)
  modpost: Initialize builtin_modname to stop SIGSEGVs
  Documentation: kbuild: note CONFIG_DEBUG_EFI in reproducible builds
  kbuild: vmlinux.unstripped should always depend on .vmlinux.export.o
  modpost: Create modalias for builtin modules
  modpost: Add modname to mod_device_table alias
  scsi: Always define blogic_pci_tbl structure
  kbuild: extract modules.builtin.modinfo from vmlinux.unstripped
  kbuild: keep .modinfo section in vmlinux.unstripped
  kbuild: always create intermediate vmlinux.unstripped
  s390: vmlinux.lds.S: Reorder sections
  KMSAN: Remove tautological checks
  objtool: Drop noinstr hack for KCSAN_WEAK_MEMORY
  lib/Kconfig.debug: Drop CLANG_VERSION check from DEBUG_INFO_DWARF_TOOLCHAIN_DEFAULT
  riscv: Remove ld.lld version checks from many TOOLCHAIN_HAS configs
  riscv: Unconditionally use linker relaxation
  riscv: Remove version check for LTO_CLANG selects
  powerpc: Drop unnecessary initializations in __copy_inst_from_kernel_nofault()
  mips: Unconditionally select ARCH_HAS_CURRENT_STACK_POINTER
  arm64: Remove tautological LLVM Kconfig conditions
  ARM: Clean up definition of ARM_HAS_GROUP_RELOCS
  ...
2025-10-01 20:58:51 -07:00
Linus Torvalds
a5ba183bde Merge tag 'hardening-v6.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux
Pull hardening updates from Kees Cook:
 "One notable addition is the creation of the 'transitional' keyword for
  kconfig so CONFIG renaming can go more smoothly.

  This has been a long-standing deficiency, and with the renaming of
  CONFIG_CFI_CLANG to CONFIG_CFI (since GCC will soon have KCFI
  support), this came up again.

  The breadth of the diffstat is mainly this renaming.

   - Clean up usage of TRAILING_OVERLAP() (Gustavo A. R. Silva)

   - lkdtm: fortify: Fix potential NULL dereference on kmalloc failure
     (Junjie Cao)

   - Add str_assert_deassert() helper (Lad Prabhakar)

   - gcc-plugins: Remove TODO_verify_il for GCC >= 16

   - kconfig: Fix BrokenPipeError warnings in selftests

   - kconfig: Add transitional symbol attribute for migration support

   - kcfi: Rename CONFIG_CFI_CLANG to CONFIG_CFI"

* tag 'hardening-v6.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
  lib/string_choices: Add str_assert_deassert() helper
  kcfi: Rename CONFIG_CFI_CLANG to CONFIG_CFI
  kconfig: Add transitional symbol attribute for migration support
  kconfig: Fix BrokenPipeError warnings in selftests
  gcc-plugins: Remove TODO_verify_il for GCC >= 16
  stddef: Introduce __TRAILING_OVERLAP()
  stddef: Remove token-pasting in TRAILING_OVERLAP()
  lkdtm: fortify: Fix potential NULL dereference on kmalloc failure
2025-09-29 17:48:27 -07:00