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gitolite.kernel.org:pub/scm/linux/kernel/git/tip/tip
Pull objtool updates from Ingo Molnar:
- A large series of KLP fixes and improvements, in preparation of the
arm64 port (Josh Poimboeuf)
- Fix a number of bugs and issues on specific distro, LTO, FineIBT and
kCFI configs (Josh Poimboeuf)
- Misc other fixes by Josh Poimboeuf and Joe Lawrence
* tag 'objtool-core-2026-06-14' of gitolite.kernel.org:pub/scm/linux/kernel/git/tip/tip: (53 commits)
objtool/klp: Cache dont_correlate() result
objtool: Improve and simplify prefix symbol detection
objtool/klp: Fix kCFI prefix finding/cloning
objtool: Grow __cfi_* prefix symbols for all CFI+CALL_PADDING
objtool/klp: Fix position-dependent checksums for non-relocated jumps/calls
objtool: Add insn_sym() helper
objtool/klp: Add correlation debugging output
objtool/klp: Rewrite symbol correlation algorithm
objtool/klp: Calculate object checksums
klp-build: Validate short-circuit prerequisites
objtool/klp: Remove "objtool --checksum"
klp-build: Use "objtool klp checksum" subcommand
objtool/klp: Add "objtool klp checksum" subcommand
objtool: Consolidate file decoding into decode_file()
objtool/klp: Extricate checksum calculation from validate_branch()
objtool: Add is_cold_func() helper
objtool: Add is_alias_sym() helper
objtool/klp: Handle Clang .data..Lanon anonymous data sections
objtool/klp: Create empty checksum sections for function-less object files
objtool: Include libsubcmd headers directly from source tree
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Pull Rust updates from Miguel Ojeda:
"This one is big due to the vendoring of the `zerocopy` library, which
allows us to replace a bunch of `unsafe` code dealing with conversions
between byte sequences and other types with safe alternatives. More
details on that below (and in its merge commit).
Toolchain and infrastructure:
- Introduce support for the 'zerocopy' library [1][2]:
Fast, safe, compile error. Pick two.
Zerocopy makes zero-cost memory manipulation effortless. We write
`unsafe` so you don't have to.
It essentially provides derivable traits (e.g. 'FromBytes') and
macros (e.g. 'transmute!') for safely converting between byte
sequences and other types. Having such support allows us to remove
some 'unsafe' code.
It is among the most downloaded Rust crates and it is also used by
the Rust compiler itself.
It is licensed under "BSD-2-Clause OR Apache-2.0 OR MIT".
The crates are imported essentially as-is (only +2/-3 lines needed
to be adapted), plus SPDX identifiers. Upstream has since added the
SPDX identifiers as well as one of the tweaks at my request, thus
reducing our future diffs on updates -- I keep the details in one
of our usual live lists [3].
In total, it is about ~39k lines added, ~32k without counting
'benches/' which are just for documentation purposes.
The series includes a few Kbuild and rust-analyzer improvements and
an example patch using it in Nova, removing one 'unsafe impl'.
I checked that the codegen of an isolated example function (similar
to the Nova patch on top) is essentially identical. It also turns
out that (for that particular case) the 'zerocopy' version, even
with 'debug-assertions' enabled, has no remaining panics, unlike a
few in the current code (since the compiler can prove the remaining
'ub_checks' statically).
So their "fast, safe" does indeed check out -- at least in that
case.
- Support AutoFDO. This allows Rust code to be profiled and optimized
based on the profile. Tested with Rust Binder: ~13% slower without
AutoFDO in the binderAddInts benchmark (using an app-launch
benchmark for the profile).
- Support Software Tag-Based KASAN.
In addition, fix KASAN Kconfig by requiring Clang.
- Add Kconfig options for each existing Rust KUnit test suite, such
as 'CONFIG_RUST_BITMAP_KUNIT_TEST'.
They are placed within a new menu, 'CONFIG_RUST_KUNIT_TESTS', in
the new 'rust/kernel/Kconfig.test' file.
- Support the upcoming Rust 1.98.0 release (expected 2026-08-20):
lint cleanups and an unstable flag rename.
- Disable 'rustdoc' documentation inlining for all prelude items,
which bloats the generated documentation.
- Ignore (in Git) and clean (in Kbuild) the (rarely) 'rustc'-generated
'*.long-type-*.txt' files.
'kernel' crate:
- Add new 'bitfield' module with the 'bitfield!' macro (extracted
from the existing 'register!' one), which declares integer types
that are split into distinct bit fields of arbitrary length.
Each field is a 'Bounded' of the appropriate bit width (ensuring
values are properly validated and avoiding implicit data loss) and
gets several generated getters and setters (infallible, 'const' and
fallible) as well as associated constants ('_MASK', '_SHIFT' and
'_RANGE'). It also supports fields that can be converted from/to
custom types, either fallibly ('?=>') or infallibly ('=>').
For instance:
bitfield! {
struct Rgb(u16) {
15:11 blue;
10:5 green;
4:0 red;
}
}
// Compile-time checks.
let color = Rgb::zeroed().with_const_green::<0x1f>();
assert_eq!(color.green(), 0x1f);
assert_eq!(color.into_raw(), 0x1f << Rgb::GREEN_SHIFT);
Add as well documentation and a test suite for it, as usual; and
update the 'register!' macro to use it.
It will be maintained by Alexandre Courbot (with Yury Norov as
reviewer) under a new 'MAINTAINERS' entry: 'RUST [BITFIELD]'.
- 'ptr' module: rework index projection syntax into keyworded syntax
and introduce panicking variant.
The keyword syntax ('build:', 'try:', 'panic:') is more explicit
and paves the way of perhaps adding more flavors in the future,
e.g. an 'unsafe' index projection.
For instance, projections now look like this:
fn f(p: *const [u8; 32]) -> Result {
// Ok, within bounds, checked at build time.
project!(p, [build: 1]);
// Build error.
project!(p, [build: 128]);
// `OutOfBound` runtime error (convertible to `ERANGE`).
project!(p, [try: 128]);
// Runtime panic.
project!(p, [panic: 128]);
Ok(())
}
Update as well the users, which now look like e.g.
// Pointer to the first entry of the GSP message queue.
let data = project!(self.0.as_ptr(), .gspq.msgq.data[build: 0]);
- 'build_assert' module: make the module the home of its macros
instead of rendering them twice.
- 'sync' module: add 'UniqueArc::as_ptr()' associated function.
- 'alloc' module:
- Fix the 'Vec::reserve()' doctest to properly account for the
existing vector length in the capacity assertion.
- Fix an incorrect operator in the 'Vec::extend_with()' 'SAFETY'
comment; add a doc test demonstrating basic usage and the
zero-length case.
- Clean imports across several modules to follow the "kernel
vertical" import style in order to minimize conflicts.
'pin-init' crate:
- User visible changes:
- Do not generate 'non_snake_case' warnings for identifiers that
are syntactically just users of a field name. This would allow
all '#[allow(non_snake_case)]' in nova-core to be removed,
which Gary will send to the nova tree next cycle.
- Filter non-cfg attributes out properly in derived structs. This
improves pin-init compatibility with other derive macros.
- Insert projection types' where clause properly.
- Other changes:
- Bump MSRV to 1.82, plus associated cleanups.
- Overhaul how init slots are projected. The new approach is
easier to justify with safety comments.
- Mark more functions as inline, which should help mitigate the
super-long symbol name issue due to lack of inlining.
rust-analyzer:
- Support '--envs' for passing env vars for crates like 'zerocopy'.
'MAINTAINERS':
- Add the following reviewers to the 'RUST' entry:
- Daniel Almeida
- Tamir Duberstein
- Alexandre Courbot
- Onur Özkan
They have been involved in the Rust for Linux project for about 7
collective years and bring expertise across several domains, which
will be very useful to have around in the future.
Thanks everyone for stepping up!
And some other fixes, cleanups and improvements"
Link: https://github.com/google/zerocopy [1]
Link: https://docs.rs/zerocopy [2]
Link: https://github.com/Rust-for-Linux/linux/issues/1239 [3]
* tag 'rust-7.2' of gitolite.kernel.org:pub/scm/linux/kernel/git/ojeda/linux: (86 commits)
MAINTAINERS: add Onur Özkan as Rust reviewer
MAINTAINERS: add Alexandre Courbot as Rust reviewer
MAINTAINERS: add Tamir Duberstein as Rust reviewer
MAINTAINERS: add Daniel Almeida as Rust reviewer
kbuild: rust: clean `zerocopy-derive` in `mrproper`
rust: make `build_assert` module the home of related macros
rust: str: clean unused import for Rust >= 1.98
rust: str: use the "kernel vertical" imports style
rust: aref: use the "kernel vertical" imports style
rust: page: use the "kernel vertical" imports style
gpu: nova-core: firmware: parse `FalconUCodeDescV2` via `zerocopy`
rust: prelude: add `zerocopy{,_derive}::FromBytes`
rust: zerocopy-derive: enable support in kbuild
rust: zerocopy-derive: add `README.md`
rust: zerocopy-derive: avoid generating non-ASCII identifiers
rust: zerocopy-derive: add SPDX License Identifiers
rust: zerocopy-derive: import crate
rust: zerocopy: enable support in kbuild
rust: zerocopy: add `README.md`
rust: zerocopy: remove float `Display` support
...
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Add distributed ThinLTO build support for the Linux kernel.
This new mode offers several advantages: (1) Increased
flexibility in handling user-specified build options.
(2) Improved user-friendliness for developers. (3) Greater
convenience for integrating with objtool and livepatch.
Note that "distributed" in this context refers to a term
that differentiates in-process ThinLTO builds by invoking
backend compilation through the linker, not necessarily
building in distributed environments.
Distributed ThinLTO is enabled via the
`CONFIG_LTO_CLANG_THIN_DIST` Kconfig option. For example:
> make LLVM=1 defconfig
> scripts/config -e LTO_CLANG_THIN_DIST
> make LLVM=1 oldconfig
> make LLVM=1 vmlinux -j <..>
The build flow proceeds in four stages:
1. Perform FE compilation, mirroring the in-process ThinLTO mode.
2. Thin-link the generated IR files and object files.
3. Find all IR files and perform BE compilation, using the flags
stored in the .*.o.cmd files.
4. Link the BE results to generate the final vmlinux.o.
NOTE: This patch currently implements the build for the main kernel
image (vmlinux) only. Kernel module support is planned for a
subsequent patch.
Tested on the following arch: x86, arm64, loongarch, and
riscv.
The earlier implementation details can be found here:
https://discourse.llvm.org/t/rfc-distributed-thinlto-build-for-kernel/85934
Signed-off-by: Rong Xu <xur@google.com>
Co-developed-by: Masahiro Yamada <masahiroy@kernel.org>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Tested-by: Piotr Gorski <piotrgorski@cachyos.org>
Tested-by: Nathan Chancellor <nathan@kernel.org>
Link: https://patch.msgid.link/20260529185347.2418373-4-xur@google.com
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
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This patch enables AutoFDO build support for Rust code within the Linux
kernel. This allows Rust code to be profiled and optimized based on the
profile.
The RUSTFLAGS variable was suffixed with *_AUTOFDO_CLANG to match the
naming of the config option, which is called CONFIG_AUTOFDO_CLANG.
This implementation has been verified in Android, first by inspecting
the object files and confirming that they look correct. After that,
it was verified as below:
1. Running the binderAddInts benchmark [1] with Rust Binder built as
rust_binder.ko module, using a Pixel 9 Pro.
2. Collecting a profile on a Pixel 10 Pro XL using the app-launch
benchmark, which starts different apps many times, on a device with
Rust Binder as a built-in kernel module. (C Binder was not present on
the device.)
3. Using the collected profile, run the binderAddInts benchmark again
with Rust Binder built both as a rust_binder.ko module, and as a
built-in kernel module.
4. In both cases, Rust Binder without AutoFDO was approximately 13%
slower than the AutoFDO optimized version. Built-in vs .ko did not
make a measurable performance difference.
All of the above was verified in conjunction with my helpers inlining
series [2], which confirmed that this worked correctly for helpers too
once [3] was fixed in the helpers inlining series.
Link: https://android.googlesource.com/platform/system/extras/+/920f089/tests/binder/benchmarks/binderAddInts.cpp [1]
Link: https://lore.kernel.org/r/20260203-inline-helpers-v2-0-beb8547a03c9@google.com [2]
Link: https://lore.kernel.org/r/aasPsbMEsX6iGUl8@google.com [3]
Reviewed-by: Rong Xu <xur@google.com>
Reviewed-by: Gary Guo <gary@garyguo.net>
Tested-by: Alice Ryhl <aliceryhl@google.com>
Signed-off-by: Alice Ryhl <aliceryhl@google.com>
Acked-by: Nicolas Schier <nsc@kernel.org>
Acked-by: Nathan Chancellor <nathan@kernel.org>
Link: https://patch.msgid.link/20260331-autofdo-v2-1-eb5c5964820d@google.com
[ Reworded for typos. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
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For all CONFIG_CFI+CONFIG_CALL_PADDING configs, for C functions, the
__cfi_ symbols only cover the 5-byte kCFI type hash. After that there
also N bytes of NOP padding between the hash and the function entry
which aren't associated with any symbol.
The NOPs can be replaced with actual code at runtime. Without a symbol,
unwinders and tooling have no way of knowing where those bytes belong.
Grow the existing __cfi_* symbols to fill that gap.
Note that assembly functions with SYM_TYPED_FUNC_START() aren't affected
by this issue, their __cfi_ symbols also cover the padding.
Also, CONFIG_PREFIX_SYMBOLS has no reason to exist: CONFIG_CALL_PADDING
is what causes the compiler to emit NOP padding before function entry
(via -fpatchable-function-entry), so it's the right condition for
creating prefix symbols.
Remove CONFIG_PREFIX_SYMBOLS, as it's no longer needed. Simplify the
LONGEST_SYM_KUNIT_TEST dependency accordingly. Rework objtool's
arguments a bit to handle the variety of prefix/cfi-related cases.
Suggested-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
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git://git.kernel.org/pub/scm/linux/kernel/git/kbuild/linux
Pull Kbuild/Kconfig updates from Nathan Chancellor:
"Kbuild:
- Drop '*_probe' pattern from modpost section check allowlist, which
hid legitimate warnings (Johan Hovold)
- Disable -Wtype-limits altogether, instead of enabling at W=2
(Vincent Mailhol)
- Improve UAPI testing to skip testing headers that require a libc
when CONFIG_CC_CAN_LINK is not set, opening up testing of headers
with no libc dependencies to more environments (Thomas Weißschuh)
- Update gendwarfksyms documentation with required dependencies
(Jihan LIN)
- Reject invalid LLVM= values to avoid unintentionally falling back
to system toolchain (Thomas Weißschuh)
- Add a script to help run the kernel build process in a container
for consistent environments and testing (Guillaume Tucker)
- Simplify kallsyms by getting rid of the relative base (Ard
Biesheuvel)
- Performance and usability improvements to scripts/make_fit.py
(Simon Glass)
- Minor various clean ups and fixes
Kconfig:
- Move XPM icons to individual files, clearing up GTK deprecation
warnings (Rostislav Krasny)
- Support
depends on FOO if BAR
as syntactic sugar for
depends on FOO || !BAR
(Nicolas Pitre, Graham Roff)
- Refactor merge_config.sh to use awk over shell/sed/grep,
dramatically speeding up processing large number of config
fragments (Anders Roxell, Mikko Rapeli)"
* tag 'kbuild-7.0-1' of git://git.kernel.org/pub/scm/linux/kernel/git/kbuild/linux: (39 commits)
kbuild: remove dependency of run-command on config
scripts/make_fit: Compress dtbs in parallel
scripts/make_fit: Support a few more parallel compressors
kbuild: Support a FIT_EXTRA_ARGS environment variable
scripts/make_fit: Move dtb processing into a function
scripts/make_fit: Support an initial ramdisk
scripts/make_fit: Speed up operation
rust: kconfig: Don't require RUST_IS_AVAILABLE for rustc-option
MAINTAINERS: Add scripts/install.sh into Kbuild entry
modpost: Amend ppc64 save/restfpr symnames for -Os build
MIPS: tools: relocs: Ship a definition of R_MIPS_PC32
streamline_config.pl: remove superfluous exclamation mark
kbuild: dummy-tools: Add python3
scripts: kconfig: merge_config.sh: warn on duplicate input files
scripts: kconfig: merge_config.sh: use awk in checks too
scripts: kconfig: merge_config.sh: refactor from shell/sed/grep to awk
kallsyms: Get rid of kallsyms relative base
mips: Add support for PC32 relocations in vmlinux
Documentation: dev-tools: add container.rst page
scripts: add tool to run containerized builds
...
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In some cases it is useful to be able to pass additional flags to the
make_fit.py script. For example, since ramdisks are typically large,
passing -E to use external data can be helpful.
Add a new FIT_EXTRA_ARGS variable for this.
Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Nicolas Schier <nsc@kernel.org>
Reviewed-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
Link: https://patch.msgid.link/20260106162738.2605574-5-sjg@chromium.org
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
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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
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With CONFIG_KLP_BUILD enabled, checksums are only needed during a
klp-build run. There's no need to enable them for normal kernel builds.
This also has the benefit of softening the xxhash dependency.
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Michael Kelley <mhklinux@outlook.com>
Link: https://patch.msgid.link/edbb1ca215e4926e02edb493b68b9d6d063e902f.1762990139.git.jpoimboe@kernel.org
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Add a klp-build script which automates the generation of a livepatch
module from a source .patch file by performing the following steps:
- Builds an original kernel with -function-sections and
-fdata-sections, plus objtool function checksumming.
- Applies the .patch file and rebuilds the kernel using the same
options.
- Runs 'objtool klp diff' to detect changed functions and generate
intermediate binary diff objects.
- Builds a kernel module which links the diff objects with some
livepatch module init code (scripts/livepatch/init.c).
- Finalizes the livepatch module (aka work around linker wreckage)
using 'objtool klp post-link'.
Acked-by: Petr Mladek <pmladek@suse.com>
Tested-by: Joe Lawrence <joe.lawrence@redhat.com>
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
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In preparation for klp-build, defer objtool validation for
CONFIG_KLP_BUILD kernels until the final pre-link archive (e.g.,
vmlinux.o, module-foo.o) is built. This will simplify the process of
generating livepatch modules.
Delayed objtool is generally preferred anyway, and is already standard
for IBT and LTO. Eventually the per-translation-unit mode will be
phased out.
Acked-by: Petr Mladek <pmladek@suse.com>
Tested-by: Joe Lawrence <joe.lawrence@redhat.com>
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
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The objtool --Werror option name is stylistically inconsistent: halfway
between GCC's single-dash capitalized -Werror and objtool's double-dash
--lowercase convention, making it unnecessarily hard to remember.
Make the 'W' lower case (--werror) for consistency with objtool's other
options.
Acked-by: Petr Mladek <pmladek@suse.com>
Tested-by: Joe Lawrence <joe.lawrence@redhat.com>
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
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In preparation for the objtool klp diff subcommand, remove the arbitrary
'kmod_' prefix from __KBUILD_MODNAME and instead add it explicitly in
the __initcall_id() macro.
This change supports the standardization of "unique" symbol naming by
ensuring the non-unique portion of the name comes before the unique
part. That will enable objtool to properly correlate symbols across
builds.
Cc: Masahiro Yamada <masahiroy@kernel.org>
Acked-by: Petr Mladek <pmladek@suse.com>
Tested-by: Joe Lawrence <joe.lawrence@redhat.com>
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
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git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild
Pull Kbuild updates from Masahiro Yamada:
- Add support for the EXPORT_SYMBOL_GPL_FOR_MODULES() macro, which
exports a symbol only to specified modules
- Improve ABI handling in gendwarfksyms
- Forcibly link lib-y objects to vmlinux even if CONFIG_MODULES=n
- Add checkers for redundant or missing <linux/export.h> inclusion
- Deprecate the extra-y syntax
- Fix a genksyms bug when including enum constants from *.symref files
* tag 'kbuild-v6.16' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (28 commits)
genksyms: Fix enum consts from a reference affecting new values
arch: use always-$(KBUILD_BUILTIN) for vmlinux.lds
kbuild: set y instead of 1 to KBUILD_{BUILTIN,MODULES}
efi/libstub: use 'targets' instead of extra-y in Makefile
module: make __mod_device_table__* symbols static
scripts/misc-check: check unnecessary #include <linux/export.h> when W=1
scripts/misc-check: check missing #include <linux/export.h> when W=1
scripts/misc-check: add double-quotes to satisfy shellcheck
kbuild: move W=1 check for scripts/misc-check to top-level Makefile
scripts/tags.sh: allow to use alternative ctags implementation
kconfig: introduce menu type enum
docs: symbol-namespaces: fix reST warning with literal block
kbuild: link lib-y objects to vmlinux forcibly even when CONFIG_MODULES=n
tinyconfig: enable CONFIG_LD_DEAD_CODE_DATA_ELIMINATION
docs/core-api/symbol-namespaces: drop table of contents and section numbering
modpost: check forbidden MODULE_IMPORT_NS("module:") at compile time
kbuild: move kbuild syntax processing to scripts/Makefile.build
Makefile: remove dependency on archscripts for header installation
Documentation/kbuild: Add new gendwarfksyms kABI rules
Documentation/kbuild: Drop section numbers
...
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git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull more MM updates from Andrew Morton:
- "zram: support algorithm-specific parameters" from Sergey Senozhatsky
adds infrastructure for passing algorithm-specific parameters into
zram. A single parameter `winbits' is implemented at this time.
- "memcg: nmi-safe kmem charging" from Shakeel Butt makes memcg
charging nmi-safe, which is required by BFP, which can operate in NMI
context.
- "Some random fixes and cleanup to shmem" from Kemeng Shi implements
small fixes and cleanups in the shmem code.
- "Skip mm selftests instead when kernel features are not present" from
Zi Yan fixes some issues in the MM selftest code.
- "mm/damon: build-enable essential DAMON components by default" from
SeongJae Park reworks DAMON Kconfig to make it easier to enable
CONFIG_DAMON.
- "sched/numa: add statistics of numa balance task migration" from Libo
Chen adds more info into sysfs and procfs files to improve visibility
into the NUMA balancer's task migration activity.
- "selftests/mm: cow and gup_longterm cleanups" from Mark Brown
provides various updates to some of the MM selftests to make them
play better with the overall containing framework.
* tag 'mm-stable-2025-06-01-14-06' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (43 commits)
mm/khugepaged: clean up refcount check using folio_expected_ref_count()
selftests/mm: fix test result reporting in gup_longterm
selftests/mm: report unique test names for each cow test
selftests/mm: add helper for logging test start and results
selftests/mm: use standard ksft_finished() in cow and gup_longterm
selftests/damon/_damon_sysfs: skip testcases if CONFIG_DAMON_SYSFS is disabled
sched/numa: add statistics of numa balance task
sched/numa: fix task swap by skipping kernel threads
tools/testing: check correct variable in open_procmap()
tools/testing/vma: add missing function stub
mm/gup: update comment explaining why gup_fast() disables IRQs
selftests/mm: two fixes for the pfnmap test
mm/khugepaged: fix race with folio split/free using temporary reference
mm: add CONFIG_PAGE_BLOCK_ORDER to select page block order
mmu_notifiers: remove leftover stub macros
selftests/mm: deduplicate test names in madv_populate
kcov: rust: add flags for KCOV with Rust
mm: rust: make CONFIG_MMU ifdefs more narrow
mmu_gather: move tlb flush for VM_PFNMAP/VM_MIXEDMAP vmas into free_pgtables()
mm/damon/Kconfig: enable CONFIG_DAMON by default
...
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Rust code is currently not instrumented properly when KCOV is enabled.
Thus, add the relevant flags to perform instrumentation correctly. This
is necessary for efficient fuzzing of Rust code.
The sanitizer-coverage features of LLVM have existed for long enough
that they are available on any LLVM version supported by rustc, so we do
not need any Kconfig feature detection. The coverage level is set to 3,
as that is the level needed by trace-pc.
We do not instrument `core` since when we fuzz the kernel, we are
looking for bugs in the kernel, not the Rust stdlib.
Link: https://lkml.kernel.org/r/20250501-rust-kcov-v2-1-b71e83e9779f@google.com
Signed-off-by: Alice Ryhl <aliceryhl@google.com>
Co-developed-by: Matthew Maurer <mmaurer@google.com>
Signed-off-by: Matthew Maurer <mmaurer@google.com>
Reviewed-by: Alexander Potapenko <glider@google.com>
Tested-by: Aleksandr Nogikh <nogikh@google.com>
Acked-by: Miguel Ojeda <ojeda@kernel.org>
Cc: Andreas Hindborg <a.hindborg@kernel.org>
Cc: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Benno Lossin <benno.lossin@proton.me>
Cc: Bill Wendling <morbo@google.com>
Cc: Björn Roy Baron <bjorn3_gh@protonmail.com>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Danilo Krummrich <dakr@kernel.org>
Cc: Dmitriy Vyukov <dvyukov@google.com>
Cc: Gary Guo <gary@garyguo.net>
Cc: Justin Stitt <justinstitt@google.com>
Cc: Masahiro Yamada <masahiroy@kernel.org>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Trevor Gross <tmgross@umich.edu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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scripts/Makefile.lib is included by the following Makefiles:
scripts/Makefile.build
scripts/Makefile.modfinal
scripts/Makefile.package
scripts/Makefile.vmlinux
scripts/Makefile.vmlinux_o
However, the last four do not need to process Kbuild syntax such as
obj-*, lib-*, subdir-*, etc.
Move the relevant code to scripts/Makefile.build.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nicolas Schier <nicolas.schier@linux.dev>
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There was no dependency between the plugins changing and the rest of the
kernel being built. This could cause strange behaviors as instrumentation
could vary between targets depending on when they were built.
Generate a new header file, gcc-plugins.h, any time the GCC plugins
change. Include the header file in compiler-version.h when its associated
feature name, GCC_PLUGINS, is defined. This will be picked up by fixdep
and force rebuilds where needed.
Add a generic "touch" kbuild command, which will be used again in
a following patch. Add a "normalize_path" string helper to make the
"TOUCH" output less ugly.
Link: https://lore.kernel.org/r/20250503184623.2572355-1-kees@kernel.org
Tested-by: Nicolas Schier <n.schier@avm.de>
Reviewed-by: Nicolas Schier <n.schier@avm.de>
Signed-off-by: Kees Cook <kees@kernel.org>
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git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild
Pull Kbuild updates from Masahiro Yamada:
- Improve performance in gendwarfksyms
- Remove deprecated EXTRA_*FLAGS and KBUILD_ENABLE_EXTRA_GCC_CHECKS
- Support CONFIG_HEADERS_INSTALL for ARCH=um
- Use more relative paths to sources files for better reproducibility
- Support the loong64 Debian architecture
- Add Kbuild bash completion
- Introduce intermediate vmlinux.unstripped for architectures that need
static relocations to be stripped from the final vmlinux
- Fix versioning in Debian packages for -rc releases
- Treat missing MODULE_DESCRIPTION() as an error
- Convert Nios2 Makefiles to use the generic rule for built-in DTB
- Add debuginfo support to the RPM package
* tag 'kbuild-v6.15' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (40 commits)
kbuild: rpm-pkg: build a debuginfo RPM
kconfig: merge_config: use an empty file as initfile
nios2: migrate to the generic rule for built-in DTB
rust: kbuild: skip `--remap-path-prefix` for `rustdoc`
kbuild: pacman-pkg: hardcode module installation path
kbuild: deb-pkg: don't set KBUILD_BUILD_VERSION unconditionally
modpost: require a MODULE_DESCRIPTION()
kbuild: make all file references relative to source root
x86: drop unnecessary prefix map configuration
kbuild: deb-pkg: add comment about future removal of KDEB_COMPRESS
kbuild: Add a help message for "headers"
kbuild: deb-pkg: remove "version" variable in mkdebian
kbuild: deb-pkg: fix versioning for -rc releases
Documentation/kbuild: Fix indentation in modules.rst example
x86: Get rid of Makefile.postlink
kbuild: Create intermediate vmlinux build with relocations preserved
kbuild: Introduce Kconfig symbol for linking vmlinux with relocations
kbuild: link-vmlinux.sh: Make output file name configurable
kbuild: do not generate .tmp_vmlinux*.map when CONFIG_VMLINUX_MAP=y
Revert "kheaders: Ignore silly-rename files"
...
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Similar to GCOV, KCOV can leave behind dead code and undefined behavior.
Warnings related to those should be ignored.
The previous commit:
6b023c784204 ("objtool: Silence more KCOV warnings")
... only did so for CONFIG_CGOV_KERNEL. Also do it for CONFIG_KCOV, but
for real this time.
Fixes the following warning:
vmlinux.o: warning: objtool: synaptics_report_mt_data: unexpected end of section .text.synaptics_report_mt_data
Fixes: 6b023c784204 ("objtool: Silence more KCOV warnings")
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: https://lore.kernel.org/r/a44ba16e194bcbc52c1cef3d3cd9051a62622723.1743481539.git.jpoimboe@kernel.org
Closes: https://lore.kernel.org/oe-kbuild-all/202503282236.UhfRsF3B-lkp@intel.com/
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Remove the following from CONFIG_OBJTOOL_WERROR:
* backtrace
* "upgraded warnings to errors" message
* cmdline args
This makes the default output less cluttered and makes it easier to spot
the actual warnings. Note the above options are still are available
with --verbose or OBJTOOL_VERBOSE=1.
Also, do the cmdline arg printing on all warnings, regardless of werror.
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: https://lore.kernel.org/r/d61df69f64b396fa6b2a1335588aad7a34ea9e71.1742852846.git.jpoimboe@kernel.org
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull objtool updates from Ingo Molnar:
- The biggest change is the new option to automatically fail the build
on objtool warnings: CONFIG_OBJTOOL_WERROR.
While there are no currently known unfixed false positives left, such
an expansion in the severity of objtool warnings inevitably creates a
risk of build failures, so it's disabled by default and depends on
!COMPILE_TEST, so it shouldn't be enabled on
allyesconfig/allmodconfig builds and won't be forced on people who
just accept build-time defaults in 'make oldconfig'.
While the option is strongly recommended, only people who enable it
explicitly should see it.
(Josh Poimboeuf)
- Disable branch profiling in noinstr code with a broad brush that
includes all of arch/x86/ and kernel/sched/. (Josh Poimboeuf)
- Create backup object files on objtool errors and print exact objtool
arguments to make failure analysis easier (Josh Poimboeuf)
- Improve noreturn handling (Josh Poimboeuf)
- Improve rodata handling (Tiezhu Yang)
- Support jump tables, switch tables and goto tables on LoongArch
(Tiezhu Yang)
- Misc cleanups and fixes (Josh Poimboeuf, David Engraf, Ingo Molnar)
* tag 'objtool-core-2025-03-22' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (22 commits)
tracing: Disable branch profiling in noinstr code
objtool: Use O_CREAT with explicit mode mask
objtool: Add CONFIG_OBJTOOL_WERROR
objtool: Create backup on error and print args
objtool: Change "warning:" to "error:" for --Werror
objtool: Add --Werror option
objtool: Add --output option
objtool: Upgrade "Linked object detected" warning to error
objtool: Consolidate option validation
objtool: Remove --unret dependency on --rethunk
objtool: Increase per-function WARN_FUNC() rate limit
objtool: Update documentation
objtool: Improve __noreturn annotation warning
objtool: Fix error handling inconsistencies in check()
x86/traps: Make exc_double_fault() consistently noreturn
LoongArch: Enable jump table for objtool
objtool/LoongArch: Add support for goto table
objtool/LoongArch: Add support for switch table
objtool: Handle PC relative relocation type
objtool: Handle different entry size of rodata
...
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Objtool warnings can be indicative of crashes, broken live patching, or
even boot failures. Ignoring them is not recommended.
Add CONFIG_OBJTOOL_WERROR to upgrade objtool warnings to errors by
enabling the objtool --Werror option. Also set --backtrace to print the
branches leading up to the warning, which can help considerably when
debugging certain warnings.
To avoid breaking bots too badly for now, make it the default for real
world builds only (!COMPILE_TEST).
Co-developed-by: Brendan Jackman <jackmanb@google.com>
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/3e7c109313ff15da6c80788965cc7450115b0196.1741975349.git.jpoimboe@kernel.org
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The imperative paradigm used to build vmlinux, extract some info from it
or perform some checks on it, and subsequently modify it again goes
against the declarative paradigm that is usually employed for defining
make rules.
In particular, the Makefile.postlink files that consume their input via
an output rule result in some dodgy logic in the decompressor makefiles
for RISC-V and x86, given that the vmlinux.relocs input file needed to
generate the arch-specific relocation tables may not exist or be out of
date, but cannot be constructed using the ordinary Make dependency based
rules, because the info needs to be extracted while vmlinux is in its
ephemeral, non-stripped form.
So instead, for architectures that require the static relocations that
are emitted into vmlinux when passing --emit-relocs to the linker, and
are subsequently stripped out again, introduce an intermediate vmlinux
target called vmlinux.unstripped, and organize the reset of the build
logic accordingly:
- vmlinux.unstripped is created only once, and not updated again
- build rules under arch/*/boot can depend on vmlinux.unstripped without
running the risk of the data disappearing or being out of date
- the final vmlinux generated by the build is not bloated with static
relocations that are never needed again after the build completes.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
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Commit f77bf01425b1 ("kbuild: introduce ccflags-y, asflags-y and
ldflags-y") deprecated these in 2007. The migration should have been
completed by now.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Kees Cook <kees@kernel.org>
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
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Since we're going to approach integer overflow mitigation a type at a
time, we need to enable all of the associated sanitizers, and then opt
into types one at a time.
Rename the existing "signed wrap" sanitizer to just the entire topic area:
"integer wrap". Enable the implicit integer truncation sanitizers, with
required callbacks and tests.
Notably, this requires features (currently) only available in Clang,
so we can depend on the cc-option tests to determine availability
instead of doing version tests.
Link: https://lore.kernel.org/r/20250307041914.937329-1-kees@kernel.org
Signed-off-by: Kees Cook <kees@kernel.org>
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Signed-off-by: Oleh Zadorozhnyi <lesorubshayan@gmail.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
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Since commit bede169618c6 ("kbuild: enable objtool for *.mod.o and
additional kernel objects"), Clang LTO builds do not perform any
optimizations when CONFIG_OBJTOOL is disabled (e.g., for ARCH=arm64).
This is because every LLVM bitcode file is immediately converted to
ELF format before the object files are linked together.
This commit fixes the breakage.
Fixes: bede169618c6 ("kbuild: enable objtool for *.mod.o and additional kernel objects")
Reported-by: Yonghong Song <yonghong.song@linux.dev>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Tested-by: Yonghong Song <yonghong.song@linux.dev>
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Due to the fact that runtime const ELF sections are named without a
leading period or double underscore, the RSTRIP logic that removes the
static RELA sections from vmlinux fails to identify them. This results
in a situation like below, where some sections that were supposed to get
removed are left behind.
[Nr] Name Type Address Off Size ES Flg Lk Inf Al
[58] runtime_shift_d_hash_shift PROGBITS ffffffff83500f50 2900f50 000014 00 A 0 0 1
[59] .relaruntime_shift_d_hash_shift RELA 0000000000000000 55b6f00 000078 18 I 70 58 8
[60] runtime_ptr_dentry_hashtable PROGBITS ffffffff83500f68 2900f68 000014 00 A 0 0 1
[61] .relaruntime_ptr_dentry_hashtable RELA 0000000000000000 55b6f78 000078 18 I 70 60 8
[62] runtime_ptr_USER_PTR_MAX PROGBITS ffffffff83500f80 2900f80 000238 00 A 0 0 1
[63] .relaruntime_ptr_USER_PTR_MAX RELA 0000000000000000 55b6ff0 000d50 18 I 70 62 8
So tweak the match expression to strip all sections starting with .rel.
While at it, consolidate the logic used by RISC-V, s390 and x86 into a
single shared Makefile library command.
Link: https://lore.kernel.org/all/CAHk-=wjk3ynjomNvFN8jf9A1k=qSc=JFF591W00uXj-qqNUxPQ@mail.gmail.com/
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Reviewed-by: Charlie Jenkins <charlie@rivosinc.com>
Tested-by: Charlie Jenkins <charlie@rivosinc.com>
Tested-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
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Replace lz4c with lz4 for kernel image compression.
Although lz4 and lz4c are functionally similar, lz4c has been deprecated
upstream since 2018. Since as early as Ubuntu 16.04 and Fedora 25, lz4
and lz4c have been packaged together, making it safe to update the
requirement from lz4c to lz4.
Consequently, some distributions and build systems, such as OpenEmbedded,
have fully transitioned to using lz4. OpenEmbedded core adopted this
change in commit fe167e082cbd ("bitbake.conf: require lz4 instead of
lz4c"), causing compatibility issues when building the mainline kernel
in the latest OpenEmbedded environment, as seen in the errors below.
This change also updates the LZ4 compression commands to make it backward
compatible by replacing stdin and stdout with the '-' option, due to some
unclear reason, the stdout keyword does not work for lz4 and '-' works for
both. In addition, this modifies the legacy '-c1' with '-9' which is also
compatible with both. This fixes the mainline kernel build failures with
the latest master OpenEmbedded builds associated with the mentioned
compatibility issues.
LZ4 arch/arm/boot/compressed/piggy_data
/bin/sh: 1: lz4c: not found
...
...
ERROR: oe_runmake failed
Link: https://github.com/lz4/lz4/pull/553
Suggested-by: Francesco Dolcini <francesco.dolcini@toradex.com>
Signed-off-by: Parth Pancholi <parth.pancholi@toradex.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
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Currently, objtool is disabled in scripts/Makefile.{modfinal,vmlinux}.
This commit moves rule_cc_o_c and rule_as_o_S to scripts/Makefile.lib
and set objtool-enabled to y there.
With this change, *.mod.o, .module-common.o, builtin-dtb.o, and
vmlinux.export.o will now be covered by objtool.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
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The cmd_cc_o_c and cmd_as_o_S macros are duplicated in
scripts/Makefile.{build,modfinal,vmlinux}.
This commit factors them out to scripts/Makefile.lib.
No functional changes are intended.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
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There has been a long-standing request to support building external
modules in a separate build directory.
This commit introduces a new environment variable, KBUILD_EXTMOD_OUTPUT,
and its shorthand Make variable, MO.
A simple usage:
$ make -C <kernel-dir> M=<module-src-dir> MO=<module-build-dir>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>
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Add the build support for using Clang's Propeller optimizer. Like
AutoFDO, Propeller uses hardware sampling to gather information
about the frequency of execution of different code paths within a
binary. This information is then used to guide the compiler's
optimization decisions, resulting in a more efficient binary.
The support requires a Clang compiler LLVM 19 or later, and the
create_llvm_prof tool
(https://github.com/google/autofdo/releases/tag/v0.30.1). This
commit is limited to x86 platforms that support PMU features
like LBR on Intel machines and AMD Zen3 BRS.
Here is an example workflow for building an AutoFDO+Propeller
optimized kernel:
1) Build the kernel on the host machine, with AutoFDO and Propeller
build config
CONFIG_AUTOFDO_CLANG=y
CONFIG_PROPELLER_CLANG=y
then
$ make LLVM=1 CLA |
