This just converts the 'cc-disable-warning' uses in the generic makefile
extrawarn script to use the plain 'cc-option' form instead. Partly to
clean things up, and partly just to have the new form get some proper
test coverage.
I'll leave the various random other uses of 'cc-disable-warning' alone
and let subsystem maintainers decide if they want to convert to the new
unified model.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This is the follow-up to commit a79be02bba ("Fix mis-uses of
'cc-option' for warning disablement") where I mentioned that the best
fix would be to just make 'cc-option' a bit smarter, and work for all
compiler options, including the '-Wno-xyzzy' pattern that it used to
accept unknown options for.
It turns out that fixing cc-option is pretty straightforward: just
rewrite any '-Wno-xyzzy' option pattern to use '-Wxyzzy' instead for
testing.
That makes the whole artificial distinction between 'cc-option' and
'cc-disable-warning' go away, and we can happily forget about the odd
build rule that you have to treat compiler options that disable warnings
specially.
The 'cc-disable-warning' helper remains as a backwards compatibility
syntax for now, but is implemented in terms of the new and improved
cc-option.
Acked-by: Masahiro Yamada <masahiroy@kernel.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Thomas Weißschuh <linux@weissschuh.net>
Cc: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull documentation updates from Jonathan Corbet:
"A moderately busy cycle for documentation this time around:
- The most significant change is the replacement of the old
kernel-doc script (a monstrous collection of Perl regexes that
predates the Git era) with a Python reimplementation. That, too, is
a horrifying collection of regexes, but in a much cleaner and more
maintainable structure that integrates far better with the Sphinx
build system.
This change has been in linux-next for the full 6.15 cycle; the
small number of problems that turned up have been addressed,
seemingly to everybody's satisfaction. The Perl kernel-doc script
remains in tree (as scripts/kernel-doc.pl) and can be used with a
command-line option if need be. Unless some reason to keep it
around materializes, it will probably go away in 6.17.
Credit goes to Mauro Carvalho Chehab for doing all this work.
- Some RTLA documentation updates
- A handful of Chinese translations
- The usual collection of typo fixes, general updates, etc"
* tag 'docs-6.16' of git://git.lwn.net/linux: (85 commits)
Docs: doc-guide: update sphinx.rst Sphinx version number
docs: doc-guide: clarify latest theme usage
Documentation/scheduler: Fix typo in sched-stats domain field description
scripts: kernel-doc: prevent a KeyError when checking output
docs: kerneldoc.py: simplify exception handling logic
MAINTAINERS: update linux-doc entry to cover new Python scripts
docs: align with scripts/syscall.tbl migration
Documentation: NTB: Fix typo
Documentation: ioctl-number: Update table intro
docs: conf.py: drop backward support for old Sphinx versions
Docs: driver-api/basics: add kobject_event interfaces
Docs: relay: editing cleanups
docs: fix "incase" typo in coresight/panic.rst
Fix spelling error for 'parallel'
docs: admin-guide: fix typos in reporting-issues.rst
docs: dmaengine: add explanation for DMA_ASYNC_TX capability
Documentation: leds: improve readibility of multicolor doc
docs: fix typo in firmware-related section
docs: Makefile: Inherit PYTHONPYCACHEPREFIX setting as env variable
Documentation: ioctl-number: Update outdated submission info
...
Pull core x86 updates from Ingo Molnar:
"Boot code changes:
- A large series of changes to reorganize the x86 boot code into a
better isolated and easier to maintain base of PIC early startup
code in arch/x86/boot/startup/, by Ard Biesheuvel.
Motivation & background:
| Since commit
|
| c88d71508e ("x86/boot/64: Rewrite startup_64() in C")
|
| dated Jun 6 2017, we have been using C code on the boot path in a way
| that is not supported by the toolchain, i.e., to execute non-PIC C
| code from a mapping of memory that is different from the one provided
| to the linker. It should have been obvious at the time that this was a
| bad idea, given the need to sprinkle fixup_pointer() calls left and
| right to manipulate global variables (including non-pointer variables)
| without crashing.
|
| This C startup code has been expanding, and in particular, the SEV-SNP
| startup code has been expanding over the past couple of years, and
| grown many of these warts, where the C code needs to use special
| annotations or helpers to access global objects.
This tree includes the first phase of this work-in-progress x86
boot code reorganization.
Scalability enhancements and micro-optimizations:
- Improve code-patching scalability (Eric Dumazet)
- Remove MFENCEs for X86_BUG_CLFLUSH_MONITOR (Andrew Cooper)
CPU features enumeration updates:
- Thorough reorganization and cleanup of CPUID parsing APIs (Ahmed S.
Darwish)
- Fix, refactor and clean up the cacheinfo code (Ahmed S. Darwish,
Thomas Gleixner)
- Update CPUID bitfields to x86-cpuid-db v2.3 (Ahmed S. Darwish)
Memory management changes:
- Allow temporary MMs when IRQs are on (Andy Lutomirski)
- Opt-in to IRQs-off activate_mm() (Andy Lutomirski)
- Simplify choose_new_asid() and generate better code (Borislav
Petkov)
- Simplify 32-bit PAE page table handling (Dave Hansen)
- Always use dynamic memory layout (Kirill A. Shutemov)
- Make SPARSEMEM_VMEMMAP the only memory model (Kirill A. Shutemov)
- Make 5-level paging support unconditional (Kirill A. Shutemov)
- Stop prefetching current->mm->mmap_lock on page faults (Mateusz
Guzik)
- Predict valid_user_address() returning true (Mateusz Guzik)
- Consolidate initmem_init() (Mike Rapoport)
FPU support and vector computing:
- Enable Intel APX support (Chang S. Bae)
- Reorgnize and clean up the xstate code (Chang S. Bae)
- Make task_struct::thread constant size (Ingo Molnar)
- Restore fpu_thread_struct_whitelist() to fix
CONFIG_HARDENED_USERCOPY=y (Kees Cook)
- Simplify the switch_fpu_prepare() + switch_fpu_finish() logic (Oleg
Nesterov)
- Always preserve non-user xfeatures/flags in __state_perm (Sean
Christopherson)
Microcode loader changes:
- Help users notice when running old Intel microcode (Dave Hansen)
- AMD: Do not return error when microcode update is not necessary
(Annie Li)
- AMD: Clean the cache if update did not load microcode (Boris
Ostrovsky)
Code patching (alternatives) changes:
- Simplify, reorganize and clean up the x86 text-patching code (Ingo
Molnar)
- Make smp_text_poke_batch_process() subsume
smp_text_poke_batch_finish() (Nikolay Borisov)
- Refactor the {,un}use_temporary_mm() code (Peter Zijlstra)
Debugging support:
- Add early IDT and GDT loading to debug relocate_kernel() bugs
(David Woodhouse)
- Print the reason for the last reset on modern AMD CPUs (Yazen
Ghannam)
- Add AMD Zen debugging document (Mario Limonciello)
- Fix opcode map (!REX2) superscript tags (Masami Hiramatsu)
- Stop decoding i64 instructions in x86-64 mode at opcode (Masami
Hiramatsu)
CPU bugs and bug mitigations:
- Remove X86_BUG_MMIO_UNKNOWN (Borislav Petkov)
- Fix SRSO reporting on Zen1/2 with SMT disabled (Borislav Petkov)
- Restructure and harmonize the various CPU bug mitigation methods
(David Kaplan)
- Fix spectre_v2 mitigation default on Intel (Pawan Gupta)
MSR API:
- Large MSR code and API cleanup (Xin Li)
- In-kernel MSR API type cleanups and renames (Ingo Molnar)
PKEYS:
- Simplify PKRU update in signal frame (Chang S. Bae)
NMI handling code:
- Clean up, refactor and simplify the NMI handling code (Sohil Mehta)
- Improve NMI duration console printouts (Sohil Mehta)
Paravirt guests interface:
- Restrict PARAVIRT_XXL to 64-bit only (Kirill A. Shutemov)
SEV support:
- Share the sev_secrets_pa value again (Tom Lendacky)
x86 platform changes:
- Introduce the <asm/amd/> header namespace (Ingo Molnar)
- i2c: piix4, x86/platform: Move the SB800 PIIX4 FCH definitions to
<asm/amd/fch.h> (Mario Limonciello)
Fixes and cleanups:
- x86 assembly code cleanups and fixes (Uros Bizjak)
- Misc fixes and cleanups (Andi Kleen, Andy Lutomirski, Andy
Shevchenko, Ard Biesheuvel, Bagas Sanjaya, Baoquan He, Borislav
Petkov, Chang S. Bae, Chao Gao, Dan Williams, Dave Hansen, David
Kaplan, David Woodhouse, Eric Biggers, Ingo Molnar, Josh Poimboeuf,
Juergen Gross, Malaya Kumar Rout, Mario Limonciello, Nathan
Chancellor, Oleg Nesterov, Pawan Gupta, Peter Zijlstra, Shivank
Garg, Sohil Mehta, Thomas Gleixner, Uros Bizjak, Xin Li)"
* tag 'x86-core-2025-05-25' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (331 commits)
x86/bugs: Fix spectre_v2 mitigation default on Intel
x86/bugs: Restructure ITS mitigation
x86/xen/msr: Fix uninitialized variable 'err'
x86/msr: Remove a superfluous inclusion of <asm/asm.h>
x86/paravirt: Restrict PARAVIRT_XXL to 64-bit only
x86/mm/64: Make 5-level paging support unconditional
x86/mm/64: Make SPARSEMEM_VMEMMAP the only memory model
x86/mm/64: Always use dynamic memory layout
x86/bugs: Fix indentation due to ITS merge
x86/cpuid: Rename hypervisor_cpuid_base()/for_each_possible_hypervisor_cpuid_base() to cpuid_base_hypervisor()/for_each_possible_cpuid_base_hypervisor()
x86/cpu/intel: Rename CPUID(0x2) descriptors iterator parameter
x86/cacheinfo: Rename CPUID(0x2) descriptors iterator parameter
x86/cpuid: Rename cpuid_get_leaf_0x2_regs() to cpuid_leaf_0x2()
x86/cpuid: Rename have_cpuid_p() to cpuid_feature()
x86/cpuid: Set <asm/cpuid/api.h> as the main CPUID header
x86/cpuid: Move CPUID(0x2) APIs into <cpuid/api.h>
x86/msr: Add rdmsrl_on_cpu() compatibility wrapper
x86/mm: Fix kernel-doc descriptions of various pgtable methods
x86/asm-offsets: Export certain 'struct cpuinfo_x86' fields for 64-bit asm use too
x86/boot: Defer initialization of VM space related global variables
...
Pull RCU updates from Joel Fernandes:
- Removed swake_up_one_online() workaround
- Reverted an incorrect rcuog wake-up fix from offline softirq
- Rust RCU Guard methods marked as inline
- Updated MAINTAINERS with Joel’s and Zqiang's new email address
- Replaced magic constant in rcu_seq_done_exact() with named constant
- Added warning mechanism to validate rcu_seq_done_exact()
- Switched SRCU polling API to use rcu_seq_done_exact()
- Commented on redundant delta check in rcu_seq_done_exact()
- Made ->gpwrap tests in rcutorture more frequent
- Fixed reuse of ARM64 images in rcutorture
- rcutorture improved to check Kconfig and reader conflict handling
- Extracted logic from rcu_torture_one_read() for clarity
- Updated LWN RCU API documentation links
- Enabled --do-rt in torture.sh for CONFIG_PREEMPT_RT
- Added tests for SRCU up/down reader primitives
- Added comments and delays checks in rcutorture
- Deprecated srcu_read_lock_lite() and srcu_read_unlock_lite() via checkpatch
- Added --do-normal and --do-no-normal to torture.sh
- Added RCU Rust binding tests to torture.sh
- Reduced CPU overcommit and removed MAXSMP/CPUMASK_OFFSTACK in TREE01
- Replaced kmalloc() with kcalloc() in rcuscale
- Refined listRCU example code for stale data elimination
- Fixed hardirq count bug for x86 in cpu_stall_cputime
- Added safety checks in rcu/nocb for offloaded rdp access
- Other miscellaneous changes
* tag 'next.2025.05.17a' of git://git.kernel.org/pub/scm/linux/kernel/git/rcu/linux: (27 commits)
rcutorture: Fix issue with re-using old images on ARM64
rcutorture: Remove MAXSMP and CPUMASK_OFFSTACK from TREE01
rcutorture: Reduce TREE01 CPU overcommit
torture: Check for "Call trace:" as well as "Call Trace:"
rcutorture: Perform more frequent testing of ->gpwrap
torture: Add testing of RCU's Rust bindings to torture.sh
torture: Add --do-{,no-}normal to torture.sh
checkpatch: Deprecate srcu_read_lock_lite() and srcu_read_unlock_lite()
rcutorture: Comment invocations of tick_dep_set_task()
rcu/nocb: Add Safe checks for access offloaded rdp
rcuscale: using kcalloc() to relpace kmalloc()
doc/RCU/listRCU: refine example code for eliminating stale data
doc: Update LWN RCU API links in whatisRCU.rst
Revert "rcu/nocb: Fix rcuog wake-up from offline softirq"
rust: sync: rcu: Mark Guard methods as inline
rcu/cpu_stall_cputime: fix the hardirq count for x86 architecture
rcu: Remove swake_up_one_online() bandaid
MAINTAINERS: Update Zqiang's email address
rcutorture: Make torture.sh --do-rt use CONFIG_PREEMPT_RT
srcu: Use rcu_seq_done_exact() for polling API
...
Uses of srcu_read_lock_lite() and srcu_read_unlock_lite() are better
served by the new srcu_read_lock_fast() and srcu_read_unlock_fast() APIs.
As in srcu_read_lock_lite() and srcu_read_unlock_lite() would never have
happened had I thought a bit harder a few months ago. Therefore, mark
them deprecated.
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Joel Fernandes <joelagnelf@nvidia.com>
Commit ac4f06789b ("kbuild: Create intermediate vmlinux build with
relocations preserved") missed replacing one occurrence of "vmlinux"
that was added during the same development cycle.
Fixes: ac4f06789b ("kbuild: Create intermediate vmlinux build with relocations preserved")
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Acked-by: Ard Biesheuvel <ardb@kernel.org>
A new on by default warning in clang [1] aims to flags instances where
const variables without static or thread local storage or const members
in aggregate types are not initialized because it can lead to an
indeterminate value. This is quite noisy for the kernel due to
instances originating from header files such as:
drivers/gpu/drm/i915/gt/intel_ring.h:62:2: error: default initialization of an object of type 'typeof (ring->size)' (aka 'const unsigned int') leaves the object uninitialized [-Werror,-Wdefault-const-init-var-unsafe]
62 | typecheck(typeof(ring->size), next);
| ^
include/linux/typecheck.h:10:9: note: expanded from macro 'typecheck'
10 | ({ type __dummy; \
| ^
include/net/ip.h:478:14: error: default initialization of an object of type 'typeof (rt->dst.expires)' (aka 'const unsigned long') leaves the object uninitialized [-Werror,-Wdefault-const-init-var-unsafe]
478 | if (mtu && time_before(jiffies, rt->dst.expires))
| ^
include/linux/jiffies.h:138:26: note: expanded from macro 'time_before'
138 | #define time_before(a,b) time_after(b,a)
| ^
include/linux/jiffies.h:128:3: note: expanded from macro 'time_after'
128 | (typecheck(unsigned long, a) && \
| ^
include/linux/typecheck.h:11:12: note: expanded from macro 'typecheck'
11 | typeof(x) __dummy2; \
| ^
include/linux/list.h:409:27: warning: default initialization of an object of type 'union (unnamed union at include/linux/list.h:409:27)' with const member leaves the object uninitialized [-Wdefault-const-init-field-unsafe]
409 | struct list_head *next = smp_load_acquire(&head->next);
| ^
include/asm-generic/barrier.h:176:29: note: expanded from macro 'smp_load_acquire'
176 | #define smp_load_acquire(p) __smp_load_acquire(p)
| ^
arch/arm64/include/asm/barrier.h:164:59: note: expanded from macro '__smp_load_acquire'
164 | union { __unqual_scalar_typeof(*p) __val; char __c[1]; } __u; \
| ^
include/linux/list.h:409:27: note: member '__val' declared 'const' here
crypto/scatterwalk.c:66:22: error: default initialization of an object of type 'struct scatter_walk' with const member leaves the object uninitialized [-Werror,-Wdefault-const-init-field-unsafe]
66 | struct scatter_walk walk;
| ^
include/crypto/algapi.h:112:15: note: member 'addr' declared 'const' here
112 | void *const addr;
| ^
fs/hugetlbfs/inode.c:733:24: error: default initialization of an object of type 'struct vm_area_struct' with const member leaves the object uninitialized [-Werror,-Wdefault-const-init-field-unsafe]
733 | struct vm_area_struct pseudo_vma;
| ^
include/linux/mm_types.h:803:20: note: member 'vm_flags' declared 'const' here
803 | const vm_flags_t vm_flags;
| ^
Silencing the instances from typecheck.h is difficult because '= {}' is
not available in older but supported compilers and '= {0}' would cause
warnings about a literal 0 being treated as NULL. While it might be
possible to come up with a local hack to silence the warning for
clang-21+, it may not be worth it since -Wuninitialized will still
trigger if an uninitialized const variable is actually used.
In all audited cases of the "field" variant of the warning, the members
are either not used in the particular call path, modified through other
means such as memset() / memcpy() because the containing object is not
const, or are within a union with other non-const members.
Since this warning does not appear to have a high signal to noise ratio,
just disable it.
Cc: stable@vger.kernel.org
Link: 576161cb60 [1]
Reported-by: Linux Kernel Functional Testing <lkft@linaro.org>
Closes: https://lore.kernel.org/CA+G9fYuNjKcxFKS_MKPRuga32XbndkLGcY-PVuoSwzv6VWbY=w@mail.gmail.com/
Reported-by: Marcus Seyfarth <m.seyfarth@gmail.com>
Closes: https://github.com/ClangBuiltLinux/linux/issues/2088
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
The dwarf.h header, which is included by
scripts/gendwarfksyms/gendwarfksyms.h, resides within elfutils-devel
or libdw-devel package.
This portion of the code is compiled under the condition that
CONFIG_GENDWARFKSYMS is enabled.
Consequently, add (elfutils-devel or libdw-devel) to BuildRequires to
prevent unforeseen compilation failures.
Fix follow possible error:
In file included from scripts/gendwarfksyms/cache.c:6:
scripts/gendwarfksyms/gendwarfksyms.h:6:10: fatal error: 'dwarf.h' file not found
6 | #include <dwarf.h>
| ^~~~~~~~~
Link: https://lore.kernel.org/all/3e52d80d-0c60-4df5-8cb5-21d4b1fce7b7@suse.com/
Fixes: f28568841a ("tools: Add gendwarfksyms")
Suggested-by: Petr Pavlu <petr.pavlu@suse.com>
Signed-off-by: WangYuli <wangyuli@uniontech.com>
Reviewed-by: Nicolas Schier <n.schier@avm.de>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
The dwarf.h header, which is included by
scripts/gendwarfksyms/gendwarfksyms.h, resides within the libdw-dev
package.
This portion of the code is compiled under the condition that
CONFIG_GENDWARFKSYMS is enabled.
Consequently, add libdw-dev to Build-Depends-Arch to prevent
unforeseen compilation failures.
Fix follow possible error:
In file included from scripts/gendwarfksyms/symbols.c:6:
scripts/gendwarfksyms/gendwarfksyms.h:6:10: fatal error: 'dwarf.h' file not found
6 | #include <dwarf.h>
| ^~~~~~~~~
Fixes: f28568841a ("tools: Add gendwarfksyms")
Reviewed-by: Sami Tolvanen <samitolvanen@google.com>
Signed-off-by: WangYuli <wangyuli@uniontech.com>
Reviewed-by: Nicolas Schier <n.schier@avm.de>
Tested-by: Nicolas Schier <n.schier@avm.de>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
The .rela.dyn section contains runtime relocations and is only emitted
for a relocatable kernel.
riscv uses this section to relocate the kernel at runtime but that section
is stripped from vmlinux. That prevents kexec to successfully load vmlinux
since it does not contain the relocations info needed.
Fixes: 559d1e45a1 ("riscv: Use --emit-relocs in order to move .rela.dyn in init")
Tested-by: Björn Töpel <bjorn@rivosinc.com>
Reviewed-by: Björn Töpel <bjorn@rivosinc.com>
Acked-by: Ard Biesheuvel <ardb@kernel.org>
Link: https://lore.kernel.org/r/20250408072851.90275-1-alexghiti@rivosinc.com
Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com>
Clang and GCC have different behaviors around disabling warnings
included in -Wall and -Wextra and the order in which flags are
specified, which is exposed by clang's new support for
-Wunterminated-string-initialization.
$ cat test.c
const char foo[3] = "FOO";
const char bar[3] __attribute__((__nonstring__)) = "BAR";
$ clang -fsyntax-only -Wextra test.c
test.c:1:21: warning: initializer-string for character array is too long, array size is 3 but initializer has size 4 (including the null terminating character); did you mean to use the 'nonstring' attribute? [-Wunterminated-string-initialization]
1 | const char foo[3] = "FOO";
| ^~~~~
$ clang -fsyntax-only -Wextra -Wno-unterminated-string-initialization test.c
$ clang -fsyntax-only -Wno-unterminated-string-initialization -Wextra test.c
test.c:1:21: warning: initializer-string for character array is too long, array size is 3 but initializer has size 4 (including the null terminating character); did you mean to use the 'nonstring' attribute? [-Wunterminated-string-initialization]
1 | const char foo[3] = "FOO";
| ^~~~~
$ gcc -fsyntax-only -Wextra test.c
test.c:1:21: warning: initializer-string for array of ‘char’ truncates NUL terminator but destination lacks ‘nonstring’ attribute (4 chars into 3 available) [-Wunterminated-string-initialization]
1 | const char foo[3] = "FOO";
| ^~~~~
$ gcc -fsyntax-only -Wextra -Wno-unterminated-string-initialization test.c
$ gcc -fsyntax-only -Wno-unterminated-string-initialization -Wextra test.c
Move -Wextra up right below -Wall in Makefile.extrawarn to ensure these
flags are at the beginning of the warning options list. Move the couple
of warning options that have been added to the main Makefile since
commit e88ca24319 ("kbuild: consolidate warning flags in
scripts/Makefile.extrawarn") to scripts/Makefile.extrawarn after -Wall /
-Wextra to ensure they get properly disabled for all compilers.
Fixes: 9d7a0577c9 ("gcc-15: disable '-Wunterminated-string-initialization' entirely for now")
Link: https://github.com/llvm/llvm-project/issues/10359
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This was triggered by one of my mis-uses causing odd build warnings on
sparc in linux-next, but while figuring out why the "obviously correct"
use of cc-option caused such odd breakage, I found eight other cases of
the same thing in the tree.
The root cause is that 'cc-option' doesn't work for checking negative
warning options (ie things like '-Wno-stringop-overflow') because gcc
will silently accept options it doesn't recognize, and so 'cc-option'
ends up thinking they are perfectly fine.
And it all works, until you have a situation where _another_ warning is
emitted. At that point the compiler will go "Hmm, maybe the user
intended to disable this warning but used that wrong option that I
didn't recognize", and generate a warning for the unrecognized negative
option.
Which explains why we have several cases of this in the tree: the
'cc-option' test really doesn't work for this situation, but most of the
time it simply doesn't matter that ity doesn't work.
The reason my recently added case caused problems on sparc was pointed
out by Thomas Weißschuh: the sparc build had a previous explicit warning
that then triggered the new one.
I think the best fix for this would be to make 'cc-option' a bit smarter
about this sitation, possibly by adding an intentional warning to the
test case that then triggers the unrecognized option warning reliably.
But the short-term fix is to replace 'cc-option' with an existing helper
designed for this exact case: 'cc-disable-warning', which picks the
negative warning but uses the positive form for testing the compiler
support.
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Link: https://lore.kernel.org/all/20250422204718.0b4e3f81@canb.auug.org.au/
Explained-by: Thomas Weißschuh <linux@weissschuh.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull rust fixes from Miguel Ojeda:
"Toolchain and infrastructure:
- Fix missing KASAN LLVM flags on first build (and fix spurious
rebuilds) by skipping '--target'
- Fix Make < 4.3 build error by using '$(pound)'
- Fix UML build error by removing 'volatile' qualifier from io
helpers
- Fix UML build error by adding 'dma_{alloc,free}_attrs()' helpers
- Clean gendwarfksyms warnings by avoiding to export '__pfx' symbols
- Clean objtool warning by adding a new 'noreturn' function for
1.86.0
- Disable 'needless_continue' Clippy lint due to new 1.86.0 warnings
- Add missing 'ffi' crate to 'generate_rust_analyzer.py'
'pin-init' crate:
- Import a couple fixes from upstream"
* tag 'rust-fixes-6.15' of git://git.kernel.org/pub/scm/linux/kernel/git/ojeda/linux:
rust: helpers: Add dma_alloc_attrs() and dma_free_attrs()
rust: helpers: Remove volatile qualifier from io helpers
rust: kbuild: use `pound` to support GNU Make < 4.3
objtool/rust: add one more `noreturn` Rust function for Rust 1.86.0
rust: kasan/kbuild: fix missing flags on first build
rust: disable `clippy::needless_continue`
rust: kbuild: Don't export __pfx symbols
rust: pin-init: use Markdown autolinks in Rust comments
rust: pin-init: alloc: restrict `impl ZeroableOption` for `Box` to `T: Sized`
scripts: generate_rust_analyzer: Add ffi crate
GNU Make 4.3 changed the behavior of `#` inside commands in commit
c6966b323811 ("[SV 20513] Un-escaped # are not comments in function
invocations"):
* WARNING: Backward-incompatibility!
Number signs (#) appearing inside a macro reference or function invocation
no longer introduce comments and should not be escaped with backslashes:
thus a call such as:
foo := $(shell echo '#')
is legal. Previously the number sign needed to be escaped, for example:
foo := $(shell echo '\#')
Now this latter will resolve to "\#". If you want to write makefiles
portable to both versions, assign the number sign to a variable:
H := \#
foo := $(shell echo '$H')
This was claimed to be fixed in 3.81, but wasn't, for some reason.
To detect this change search for 'nocomment' in the .FEATURES variable.
Unlike other commits in the kernel about this issue, such as commit
633174a704 ("lib/raid6/test/Makefile: Use $(pound) instead of \#
for Make 4.3"), that fixed the issue for newer GNU Makes, in our case
it was the opposite, i.e. we need to fix it for the older ones: someone
building with e.g. 4.2.1 gets the following error:
scripts/Makefile.compiler:81: *** unterminated call to function 'call': missing ')'. Stop.
Thus use the existing variable to fix it.
Reported-by: moyi geek <1441339168@qq.com>
Closes: https://rust-for-linux.zulipchat.com/#narrow/channel/291565/topic/x/near/512001985
Cc: stable@vger.kernel.org
Fixes: e72a076c62 ("kbuild: fix issues with rustc-option")
Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Link: https://lore.kernel.org/r/20250414171241.2126137-1-ojeda@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
If KASAN is enabled, and one runs in a clean repository e.g.:
make LLVM=1 prepare
make LLVM=1 prepare
Then the Rust code gets rebuilt, which should not happen.
The reason is some of the LLVM KASAN `rustc` flags are added in the
second run:
-Cllvm-args=-asan-instrumentation-with-call-threshold=10000
-Cllvm-args=-asan-stack=0
-Cllvm-args=-asan-globals=1
-Cllvm-args=-asan-kernel-mem-intrinsic-prefix=1
Further runs do not rebuild Rust because the flags do not change anymore.
Rebuilding like that in the second run is bad, even if this just happens
with KASAN enabled, but missing flags in the first one is even worse.
The root issue is that we pass, for some architectures and for the moment,
a generated `target.json` file. That file is not ready by the time `rustc`
gets called for the flag test, and thus the flag test fails just because
the file is not available, e.g.:
$ ... --target=./scripts/target.json ... -Cllvm-args=...
error: target file "./scripts/target.json" does not exist
There are a few approaches we could take here to solve this. For instance,
we could ensure that every time that the config is rebuilt, we regenerate
the file and recompute the flags. Or we could use the LLVM version to
check for these flags, instead of testing the flag (which may have other
advantages, such as allowing us to detect renames on the LLVM side).
However, it may be easier than that: `rustc` is aware of the `-Cllvm-args`
regardless of the `--target` (e.g. I checked that the list printed
is the same, plus that I can check for these flags even if I pass
a completely unrelated target), and thus we can just eliminate the
dependency completely.
Thus filter out the target.
This does mean that `rustc-option` cannot be used to test a flag that
requires the right target, but we don't have other users yet, it is a
minimal change and we want to get rid of custom targets in the future.
We could only filter in the case `target.json` is used, to make it work
in more cases, but then it would be harder to notice that it may not
work in a couple architectures.
Cc: Matthew Maurer <mmaurer@google.com>
Cc: Sami Tolvanen <samitolvanen@google.com>
Cc: stable@vger.kernel.org
Fixes: e3117404b4 ("kbuild: rust: Enable KASAN support")
Tested-by: Alice Ryhl <aliceryhl@google.com>
Link: https://lore.kernel.org/r/20250408220311.1033475-1-ojeda@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
The filtering logic was seeking for the DOC name to check for
symbols, but such data is stored only inside a section. Add it
to the output_declaration, as it is quicker/easier to check
the declaration name than to check inside each section.
While here, make sure that the output for both ReST and man
after filtering will be similar to what kernel-doc Perl
version does.
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Link: https://lore.kernel.org/r/6d8b77af85295452c0191863ea1041f4195aeaaf.1744106242.git.mchehab+huawei@kernel.org
Instead of setting file lists at __init__ time, move it to
the actual parsing function. This allows adding more files
to be parsed in real time, by calling parse function multiple
times.
With the new way, the export_files logic was rewritten to
avoid parsing twice EXPORT_SYMBOL for partial matches.
Please notice that, with this logic, it can still read the
same file twice when export_file is used.
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Link: https://lore.kernel.org/r/ab10bc94050406ce6536d4944b5d718ecd70812f.1744106242.git.mchehab+huawei@kernel.org
