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]
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
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
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>::new::<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`
...
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
...
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()
...
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>
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>
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>
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>
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>
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.
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()
...
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
...
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
This pattern isn't very documented, and apparently not used much outside
of 'make tools/help', but it has existed for over a decade (since commit
ea01fa9f63: "tools: Connect to the kernel build system").
However, it doesn't work very well for most cases, particularly the
useful "tools/all" target, because it overrides the LDFLAGS value with
an empty one.
And once overridden, 'make' will then not honor the tooling makefiles
trying to change it - which then makes any LDFLAGS use in the tooling
directory break, typically causing odd link errors.
Remove that LDFLAGS override, since it seems to be entirely historical.
The core kernel makefiles no longer modify LDFLAGS as part of the build,
and use kernel-specific link flags instead (eg 'KBUILD_LDFLAGS' and
friends).
This allows more of the 'make tools/*' cases to work. I say 'more',
because some of the tooling build rules make various other assumptions
or have other issues, so it's still a bit hit-or-miss. But those issues
tend to show up with the 'make -C tools xyz' pattern too, so now it's no
longer an issue of this particular 'tools/*' build rule being special.
Acked-by: Nathan Chancellor <nathan@kernel.org>
Cc: Nicolas Schier <nicolas@fjasle.eu>
Cc: Borislav Petkov <bp@alien8.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The kernel's CFI implementation uses the KCFI ABI specifically, and is
not strictly tied to a particular compiler. In preparation for GCC
supporting KCFI, rename CONFIG_CFI_CLANG to CONFIG_CFI (along with
associated options).
Use new "transitional" Kconfig option for old CONFIG_CFI_CLANG that will
enable CONFIG_CFI during olddefconfig.
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
Link: https://lore.kernel.org/r/20250923213422.1105654-3-kees@kernel.org
Signed-off-by: Kees Cook <kees@kernel.org>
Commit bd7c231212 ("pinctrl: meson: Fix typo in device table macro")
is needed in kbuild-next to avoid a build error with a future change.
While at it, address the conflict between commit 41f9049cff ("riscv:
Only allow LTO with CMODEL_MEDANY") and commit 6578a1ff6a ("riscv:
Remove version check for LTO_CLANG selects"), as reported by Stephen
Rothwell [1].
Link: https://lore.kernel.org/20250908134913.68778b7b@canb.auug.org.au/ [1]
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Pull Kbuild updates from Masahiro Yamada:
"This is the last pull request from me.
I'm grateful to have been able to continue as a maintainer for eight
years. From the next cycle, Nathan and Nicolas will maintain Kbuild.
- Fix a shortcut key issue in menuconfig
- Fix missing rebuild of kheaders
- Sort the symbol dump generated by gendwarfsyms
- Support zboot extraction in scripts/extract-vmlinux
- Migrate gconfig to GTK 3
- Add TAR variable to allow overriding the default tar command
- Hand over Kbuild maintainership"
* tag 'kbuild-v6.17-2' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (92 commits)
MAINTAINERS: hand over Kbuild maintenance
kheaders: make it possible to override TAR
kbuild: userprogs: use correct linker when mixing clang and GNU ld
kconfig: lxdialog: replace strcpy() with strncpy() in inputbox.c
kconfig: lxdialog: replace strcpy with snprintf in print_autowrap
kconfig: gconf: refactor text_insert_help()
kconfig: gconf: remove unneeded variable in text_insert_msg
kconfig: gconf: use hyphens in signals
kconfig: gconf: replace GtkImageMenuItem with GtkMenuItem
kconfig: gconf: Fix Back button behavior
kconfig: gconf: fix single view to display dependent symbols correctly
scripts: add zboot support to extract-vmlinux
gendwarfksyms: order -T symtypes output by name
gendwarfksyms: use preferred form of sizeof for allocation
kconfig: qconf: confine {begin,end}Group to constructor and destructor
kconfig: qconf: fix ConfigList::updateListAllforAll()
kconfig: add a function to dump all menu entries in a tree-like format
kconfig: gconf: show GTK version in About dialog
kconfig: gconf: replace GtkHPaned and GtkVPaned with GtkPaned
kconfig: gconf: replace GdkColor with GdkRGBA
...
Commit 86cdd2fdc4 ("kheaders: make headers archive reproducible")
introduced a number of options specific to GNU tar to the `tar`
invocation in `gen_kheaders.sh` script. This causes the script to fail
to work on systems where `tar` is not GNU tar. This can occur e.g.
on recent Gentoo Linux installations that support using bsdtar from
libarchive instead.
Add a `TAR` make variable to make it possible to override the tar
executable used, e.g. by specifying:
make TAR=gtar
Link: https://bugs.gentoo.org/884061
Reported-by: Sam James <sam@gentoo.org>
Tested-by: Sam James <sam@gentoo.org>
Co-developed-by: Masahiro Yamada <masahiroy@kernel.org>
Signed-off-by: Michał Górny <mgorny@gentoo.org>
Signed-off-by: Sam James <sam@gentoo.org>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
The userprogs infrastructure does not expect clang being used with GNU ld
and in that case uses /usr/bin/ld for linking, not the configured $(LD).
This fallback is problematic as it will break when cross-compiling.
Mixing clang and GNU ld is used for example when building for SPARC64,
as ld.lld is not sufficient; see Documentation/kbuild/llvm.rst.
Relax the check around --ld-path so it gets used for all linkers.
Fixes: dfc1b168a8 ("kbuild: userprogs: use correct lld when linking through clang")
Cc: stable@vger.kernel.org
Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Pull Rust updates from Miguel Ojeda:
"Toolchain and infrastructure:
- Enable a set of Clippy lints: 'ptr_as_ptr', 'ptr_cast_constness',
'as_ptr_cast_mut', 'as_underscore', 'cast_lossless' and
'ref_as_ptr'
These are intended to avoid type casts with the 'as' operator,
which are quite powerful, into restricted variants that are less
powerful and thus should help to avoid mistakes
- Remove the 'author' key now that most instances were moved to the
plural one in the previous cycle
'kernel' crate:
- New 'bug' module: add 'warn_on!' macro which reuses the existing
'BUG'/'WARN' infrastructure, i.e. it respects the usual sysctls and
kernel parameters:
warn_on!(value == 42);
To avoid duplicating the assembly code, the same strategy is
followed as for the static branch code in order to share the
assembly between both C and Rust
This required a few rearrangements on C arch headers -- the
existing C macros should still generate the same outputs, thus no
functional change expected there
- 'workqueue' module: add delayed work items, including a
'DelayedWork' struct, a 'impl_has_delayed_work!' macro and an
'enqueue_delayed' method, e.g.:
/// Enqueue the struct for execution on the system workqueue,
/// where its value will be printed 42 jiffies later.
fn print_later(value: Arc<MyStruct>) {
let _ = workqueue::system().enqueue_delayed(value, 42);
}
- New 'bits' module: add support for 'bit' and 'genmask' functions,
with runtime- and compile-time variants, e.g.:
static_assert!(0b00010000 == bit_u8(4));
static_assert!(0b00011110 == genmask_u8(1..=4));
assert!(checked_bit_u32(u32::BITS).is_none());
- 'uaccess' module: add 'UserSliceReader::strcpy_into_buf', which
reads NUL-terminated strings from userspace into a '&CStr'
Introduce 'UserPtr' newtype, similar in purpose to '__user' in C,
to minimize mistakes handling userspace pointers, including mixing
them up with integers and leaking them via the 'Debug' trait. Add
it to the prelude, too
- Start preparations for the replacement of our custom 'CStr' type
with the analogous type in the 'core' standard library. This will
take place across several cycles to make it easier. For this one,
it includes a new 'fmt' module, using upstream method names and
some other cleanups
Replace 'fmt!' with a re-export, which helps Clippy lint properly,
and clean up the found 'uninlined-format-args' instances
- 'dma' module:
- Clarify wording and be consistent in 'coherent' nomenclature
- Convert the 'read!()' and 'write!()' macros to return a 'Result'
- Add 'as_slice()', 'write()' methods in 'CoherentAllocation'
- Expose 'count()' and 'size()' in 'CoherentAllocation' and add
the corresponding type invariants
- Implement 'CoherentAllocation::dma_handle_with_offset()'
- 'time' module:
- Make 'Instant' generic over clock source. This allows the
compiler to assert that arithmetic expressions involving the
'Instant' use 'Instants' based on the same clock source
- Make 'HrTimer' generic over the timer mode. 'HrTimer' timers
take a 'Duration' or an 'Instant' when setting the expiry time,
depending on the timer mode. With this change, the compiler can
check the type matches the timer mode
- Add an abstraction for 'fsleep'. 'fsleep' is a flexible sleep
function that will select an appropriate sleep method depending
on the requested sleep time
- Avoid 64-bit divisions on 32-bit hardware when calculating
timestamps
- Seal the 'HrTimerMode' trait. This prevents users of the
'HrTimerMode' from implementing the trait on their own types
- Pass the correct timer mode ID to 'hrtimer_start_range_ns()'
- 'list' module: remove 'OFFSET' constants, allowing to remove
pointer arithmetic; now 'impl_list_item!' invokes
'impl_has_list_links!' or 'impl_has_list_links_self_ptr!'. Other
simplifications too
- 'types' module: remove 'ForeignOwnable::PointedTo' in favor of a
constant, which avoids exposing the type of the opaque pointer, and
require 'into_foreign' to return non-null
Remove the 'Either<L, R>' type as well. It is unused, and we want
to encourage the use of custom enums for concrete use cases
- 'sync' module: implement 'Borrow' and 'BorrowMut' for 'Arc' types
to allow them to be used in generic APIs
- 'alloc' module: implement 'Borrow' and 'BorrowMut' for 'Box<T, A>';
and 'Borrow', 'BorrowMut' and 'Default' for 'Vec<T, A>'
- 'Opaque' type: add 'cast_from' method to perform a restricted cast
that cannot change the inner type and use it in callers of
'container_of!'. Rename 'raw_get' to 'cast_into' to match it
- 'rbtree' module: add 'is_empty' method
- 'sync' module: new 'aref' submodule to hold 'AlwaysRefCounted' and
'ARef', which are moved from the too general 'types' module which
we want to reduce or eventually remove. Also fix a safety comment
in 'static_lock_class'
'pin-init' crate:
- Add 'impl<T, E> [Pin]Init<T, E> for Result<T, E>', so results are
now (pin-)initializers
- Add 'Zeroable::init_zeroed()' that delegates to 'init_zeroed()'
- New 'zeroed()', a safe version of 'mem::zeroed()' and also provide
it via 'Zeroable::zeroed()'
- Implement 'Zeroable' for 'Option<&T>', 'Option<&mut T>' and for
'Option<[unsafe] [extern "abi"] fn(...args...) -> ret>' for
'"Rust"' and '"C"' ABIs and up to 20 arguments
- Changed blanket impls of 'Init' and 'PinInit' from 'impl<T, E>
[Pin]Init<T, E> for T' to 'impl<T> [Pin]Init<T> for T'
- Renamed 'zeroed()' to 'init_zeroed()'
- Upstream dev news: improve CI more to deny warnings, use
'--all-targets'. Check the synchronization status of the two
'-next' branches in upstream and the kernel
MAINTAINERS:
- Add Vlastimil Babka, Liam R. Howlett, Uladzislau Rezki and Lorenzo
Stoakes as reviewers (thanks everyone)
And a few other cleanups and improvements"
* tag 'rust-6.17' of git://git.kernel.org/pub/scm/linux/kernel/git/ojeda/linux: (76 commits)
rust: Add warn_on macro
arm64/bug: Add ARCH_WARN_ASM macro for BUG/WARN asm code sharing with Rust
riscv/bug: Add ARCH_WARN_ASM macro for BUG/WARN asm code sharing with Rust
x86/bug: Add ARCH_WARN_ASM macro for BUG/WARN asm code sharing with Rust
rust: kernel: move ARef and AlwaysRefCounted to sync::aref
rust: sync: fix safety comment for `static_lock_class`
rust: types: remove `Either<L, R>`
rust: kernel: use `core::ffi::CStr` method names
rust: str: add `CStr` methods matching `core::ffi::CStr`
rust: str: remove unnecessary qualification
rust: use `kernel::{fmt,prelude::fmt!}`
rust: kernel: add `fmt` module
rust: kernel: remove `fmt!`, fix clippy::uninlined-format-args
scripts: rust: emit path candidates in panic message
scripts: rust: replace length checks with match
rust: list: remove nonexistent generic parameter in link
rust: bits: add support for bits/genmask macros
rust: list: remove OFFSET constants
rust: list: add `impl_list_item!` examples
rust: list: use fully qualified path
...
Pull hardening updates from Kees Cook:
- Introduce and start using TRAILING_OVERLAP() helper for fixing
embedded flex array instances (Gustavo A. R. Silva)
- mux: Convert mux_control_ops to a flex array member in mux_chip
(Thorsten Blum)
- string: Group str_has_prefix() and strstarts() (Andy Shevchenko)
- Remove KCOV instrumentation from __init and __head (Ritesh Harjani,
Kees Cook)
- Refactor and rename stackleak feature to support Clang
- Add KUnit test for seq_buf API
- Fix KUnit fortify test under LTO
* tag 'hardening-v6.17-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux: (22 commits)
sched/task_stack: Add missing const qualifier to end_of_stack()
kstack_erase: Support Clang stack depth tracking
kstack_erase: Add -mgeneral-regs-only to silence Clang warnings
init.h: Disable sanitizer coverage for __init and __head
kstack_erase: Disable kstack_erase for all of arm compressed boot code
x86: Handle KCOV __init vs inline mismatches
arm64: Handle KCOV __init vs inline mismatches
s390: Handle KCOV __init vs inline mismatches
arm: Handle KCOV __init vs inline mismatches
mips: Handle KCOV __init vs inline mismatch
powerpc/mm/book3s64: Move kfence and debug_pagealloc related calls to __init section
configs/hardening: Enable CONFIG_INIT_ON_FREE_DEFAULT_ON
configs/hardening: Enable CONFIG_KSTACK_ERASE
stackleak: Split KSTACK_ERASE_CFLAGS from GCC_PLUGINS_CFLAGS
stackleak: Rename stackleak_track_stack to __sanitizer_cov_stack_depth
stackleak: Rename STACKLEAK to KSTACK_ERASE
seq_buf: Introduce KUnit tests
string: Group str_has_prefix() and strstarts()
kunit/fortify: Add back "volatile" for sizeof() constants
acpi: nfit: intel: avoid multiple -Wflex-array-member-not-at-end warnings
...
