Pull printk updates from Petr Mladek:
- Add KUnit test for the printk ring buffer
- Fix the check of the maximal record size which is allowed to be
stored into the printk ring buffer. It prevents corruptions of the
ring buffer.
Note that printk() is on the safe side. The messages are limited by
1kB buffer and are always small enough for the minimal log buffer
size 4kB, see CONFIG_LOG_BUF_SHIFT definition.
* tag 'printk-for-6.18' of git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux:
printk: ringbuffer: Fix data block max size check
printk: kunit: support offstack cpumask
printk: kunit: Fix __counted_by() in struct prbtest_rbdata
printk: ringbuffer: Explain why the KUnit test ignores failed writes
printk: ringbuffer: Add KUnit test
Pull non-MM updates from Andrew Morton:
- "ida: Remove the ida_simple_xxx() API" from Christophe Jaillet
completes the removal of this legacy IDR API
- "panic: introduce panic status function family" from Jinchao Wang
provides a number of cleanups to the panic code and its various
helpers, which were rather ad-hoc and scattered all over the place
- "tools/delaytop: implement real-time keyboard interaction support"
from Fan Yu adds a few nice user-facing usability changes to the
delaytop monitoring tool
- "efi: Fix EFI boot with kexec handover (KHO)" from Evangelos
Petrongonas fixes a panic which was happening with the combination of
EFI and KHO
- "Squashfs: performance improvement and a sanity check" from Phillip
Lougher teaches squashfs's lseek() about SEEK_DATA/SEEK_HOLE. A mere
150x speedup was measured for a well-chosen microbenchmark
- plus another 50-odd singleton patches all over the place
* tag 'mm-nonmm-stable-2025-10-02-15-29' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (75 commits)
Squashfs: reject negative file sizes in squashfs_read_inode()
kallsyms: use kmalloc_array() instead of kmalloc()
MAINTAINERS: update Sibi Sankar's email address
Squashfs: add SEEK_DATA/SEEK_HOLE support
Squashfs: add additional inode sanity checking
lib/genalloc: fix device leak in of_gen_pool_get()
panic: remove CONFIG_PANIC_ON_OOPS_VALUE
ocfs2: fix double free in user_cluster_connect()
checkpatch: suppress strscpy warnings for userspace tools
cramfs: fix incorrect physical page address calculation
kernel: prevent prctl(PR_SET_PDEATHSIG) from racing with parent process exit
Squashfs: fix uninit-value in squashfs_get_parent
kho: only fill kimage if KHO is finalized
ocfs2: avoid extra calls to strlen() after ocfs2_sprintf_system_inode_name()
kernel/sys.c: fix the racy usage of task_lock(tsk->group_leader) in sys_prlimit64() paths
sched/task.h: fix the wrong comment on task_lock() nesting with tasklist_lock
coccinelle: platform_no_drv_owner: handle also built-in drivers
coccinelle: of_table: handle SPI device ID tables
lib/decompress: use designated initializers for struct compress_format
efi: support booting with kexec handover (KHO)
...
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 VDSO updates from Thomas Gleixner:
- Further consolidation of the VDSO infrastructure and the common data
store
- Simplification of the related Kconfig logic
- Improve the VDSO selftest suite
* tag 'timers-vdso-2025-09-29' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
selftests: vDSO: Drop vdso_test_clock_getres
selftests: vDSO: vdso_test_abi: Add tests for clock_gettime64()
selftests: vDSO: vdso_test_abi: Test CPUTIME clocks
selftests: vDSO: vdso_test_abi: Use explicit indices for name array
selftests: vDSO: vdso_test_abi: Drop clock availability tests
selftests: vDSO: vdso_test_abi: Use ksft_finished()
selftests: vDSO: vdso_test_abi: Correctly skip whole test with missing vDSO
selftests: vDSO: Fix -Wunitialized in powerpc VDSO_CALL() wrapper
vdso: Add struct __kernel_old_timeval forward declaration to gettime.h
vdso: Gate VDSO_GETRANDOM behind HAVE_GENERIC_VDSO
vdso: Drop Kconfig GENERIC_VDSO_TIME_NS
vdso: Drop Kconfig GENERIC_VDSO_DATA_STORE
vdso: Drop kconfig GENERIC_COMPAT_VDSO
vdso: Drop kconfig GENERIC_VDSO_32
riscv: vdso: Untangle Kconfig logic
time: Build generic update_vsyscall() only with generic time vDSO
vdso/gettimeofday: Remove !CONFIG_TIME_NS stubs
vdso: Move ENABLE_COMPAT_VDSO from core to arm64
ARM: VDSO: Remove cntvct_ok global variable
vdso/datastore: Gate time data behind CONFIG_GENERIC_GETTIMEOFDAY
Pull cgroup updates from Tejun Heo:
- Extensive cpuset code cleanup and refactoring work with no functional
changes: CPU mask computation logic refactoring, introducing new
helpers, removing redundant code paths, and improving error handling
for better maintainability.
- A few bug fixes to cpuset including fixes for partition creation
failures when isolcpus is in use, missing error returns, and null
pointer access prevention in free_tmpmasks().
- Core cgroup changes include replacing the global percpu_rwsem with
per-threadgroup rwsem when writing to cgroup.procs for better
scalability, workqueue conversions to use WQ_PERCPU and
system_percpu_wq to prepare for workqueue default switching from
percpu to unbound, and removal of unused code including the
post_attach callback.
- New cgroup.stat.local time accounting feature that tracks frozen time
duration.
- Misc changes including selftests updates (new freezer time tests and
backward compatibility fixes), documentation sync, string function
safety improvements, and 64-bit division fixes.
* tag 'cgroup-for-6.18' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup: (39 commits)
cpuset: remove is_prs_invalid helper
cpuset: remove impossible warning in update_parent_effective_cpumask
cpuset: remove redundant special case for null input in node mask update
cpuset: fix missing error return in update_cpumask
cpuset: Use new excpus for nocpu error check when enabling root partition
cpuset: fix failure to enable isolated partition when containing isolcpus
Documentation: cgroup-v2: Sync manual toctree
cpuset: use partition_cpus_change for setting exclusive cpus
cpuset: use parse_cpulist for setting cpus.exclusive
cpuset: introduce partition_cpus_change
cpuset: refactor cpus_allowed_validate_change
cpuset: refactor out validate_partition
cpuset: introduce cpus_excl_conflict and mems_excl_conflict helpers
cpuset: refactor CPU mask buffer parsing logic
cpuset: Refactor exclusive CPU mask computation logic
cpuset: change return type of is_partition_[in]valid to bool
cpuset: remove unused assignment to trialcs->partition_root_state
cpuset: move the root cpuset write check earlier
cgroup/cpuset: Remove redundant rcu_read_lock/unlock() in spin_lock
cgroup: Remove redundant rcu_read_lock/unlock() in spin_lock
...
Pull s390 updates from Alexander Gordeev:
- Refactor SCLP memory hotplug code
- Introduce common boot_panic() decompressor helper macro and use it to
get rid of nearly few identical implementations
- Take into account additional key generation flags and forward it to
the ep11 implementation. With that allow users to modify the key
generation process, e.g. provide valid combinations of XCP_BLOB_*
flags
- Replace kmalloc() + copy_from_user() with memdup_user_nul() in s390
debug facility and HMC driver
- Add DAX support for DCSS memory block devices
- Make the compiler statement attribute "assume" available with a new
__assume macro
- Rework ffs() and fls() family bitops functions, including source code
improvements and generated code optimizations. Use the newly
introduced __assume macro for that
- Enable additional network features in default configurations
- Use __GFP_ACCOUNT flag for user page table allocations to add missing
kmemcg accounting
- Add WQ_PERCPU flag to explicitly request the use of the per-CPU
workqueue for 3590 tape driver
- Switch power reading to the per-CPU and the Hiperdispatch to the
default workqueue
- Add memory allocation profiling hooks to allow better profiling data
and the /proc/allocinfo output similar to other architectures
* tag 's390-6.18-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (21 commits)
s390/mm: Add memory allocation profiling hooks
s390: Replace use of system_wq with system_dfl_wq
s390/diag324: Replace use of system_wq with system_percpu_wq
s390/tape: Add WQ_PERCPU to alloc_workqueue users
s390/bitops: Switch to generic ffs() if supported by compiler
s390/bitops: Switch to generic fls(), fls64(), etc.
s390/mm: Use __GFP_ACCOUNT for user page table allocations
s390/configs: Enable additional network features
s390/bitops: Cleanup __flogr()
s390/bitops: Use __assume() for __flogr() inline assembly return value
compiler_types: Add __assume macro
s390/bitops: Limit return value range of __flogr()
s390/dcssblk: Add DAX support
s390/hmcdrv: Replace kmalloc() + copy_from_user() with memdup_user_nul()
s390/debug: Replace kmalloc() + copy_from_user() with memdup_user_nul()
s390/pkey: Forward keygenflags to ep11_unwrapkey
s390/boot: Add common boot_panic() code
s390/bitops: Optimize inlining
s390/bitops: Slightly optimize ffs() and fls64()
s390/sclp: Move memory hotplug code for better modularity
...
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
Pull namespace updates from Christian Brauner:
"This contains a larger set of changes around the generic namespace
infrastructure of the kernel.
Each specific namespace type (net, cgroup, mnt, ...) embedds a struct
ns_common which carries the reference count of the namespace and so
on.
We open-coded and cargo-culted so many quirks for each namespace type
that it just wasn't scalable anymore. So given there's a bunch of new
changes coming in that area I've started cleaning all of this up.
The core change is to make it possible to correctly initialize every
namespace uniformly and derive the correct initialization settings
from the type of the namespace such as namespace operations, namespace
type and so on. This leaves the new ns_common_init() function with a
single parameter which is the specific namespace type which derives
the correct parameters statically. This also means the compiler will
yell as soon as someone does something remotely fishy.
The ns_common_init() addition also allows us to remove ns_alloc_inum()
and drops any special-casing of the initial network namespace in the
network namespace initialization code that Linus complained about.
Another part is reworking the reference counting. The reference
counting was open-coded and copy-pasted for each namespace type even
though they all followed the same rules. This also removes all open
accesses to the reference count and makes it private and only uses a
very small set of dedicated helpers to manipulate them just like we do
for e.g., files.
In addition this generalizes the mount namespace iteration
infrastructure introduced a few cycles ago. As reminder, the vfs makes
it possible to iterate sequentially and bidirectionally through all
mount namespaces on the system or all mount namespaces that the caller
holds privilege over. This allow userspace to iterate over all mounts
in all mount namespaces using the listmount() and statmount() system
call.
Each mount namespace has a unique identifier for the lifetime of the
systems that is exposed to userspace. The network namespace also has a
unique identifier working exactly the same way. This extends the
concept to all other namespace types.
The new nstree type makes it possible to lookup namespaces purely by
their identifier and to walk the namespace list sequentially and
bidirectionally for all namespace types, allowing userspace to iterate
through all namespaces. Looking up namespaces in the namespace tree
works completely locklessly.
This also means we can move the mount namespace onto the generic
infrastructure and remove a bunch of code and members from struct
mnt_namespace itself.
There's a bunch of stuff coming on top of this in the future but for
now this uses the generic namespace tree to extend a concept
introduced first for pidfs a few cycles ago. For a while now we have
supported pidfs file handles for pidfds. This has proven to be very
useful.
This extends the concept to cover namespaces as well. It is possible
to encode and decode namespace file handles using the common
name_to_handle_at() and open_by_handle_at() apis.
As with pidfs file handles, namespace file handles are exhaustive,
meaning it is not required to actually hold a reference to nsfs in
able to decode aka open_by_handle_at() a namespace file handle.
Instead the FD_NSFS_ROOT constant can be passed which will let the
kernel grab a reference to the root of nsfs internally and thus decode
the file handle.
Namespaces file descriptors can already be derived from pidfds which
means they aren't subject to overmount protection bugs. IOW, it's
irrelevant if the caller would not have access to an appropriate
/proc/<pid>/ns/ directory as they could always just derive the
namespace based on a pidfd already.
It has the same advantage as pidfds. It's possible to reliably and for
the lifetime of the system refer to a namespace without pinning any
resources and to compare them trivially.
Permission checking is kept simple. If the caller is located in the
namespace the file handle refers to they are able to open it otherwise
they must hold privilege over the owning namespace of the relevant
namespace.
The namespace file handle layout is exposed as uapi and has a stable
and extensible format. For now it simply contains the namespace
identifier, the namespace type, and the inode number. The stable
format means that userspace may construct its own namespace file
handles without going through name_to_handle_at() as they are already
allowed for pidfs and cgroup file handles"
* tag 'namespace-6.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: (65 commits)
ns: drop assert
ns: move ns type into struct ns_common
nstree: make struct ns_tree private
ns: add ns_debug()
ns: simplify ns_common_init() further
cgroup: add missing ns_common include
ns: use inode initializer for initial namespaces
selftests/namespaces: verify initial namespace inode numbers
ns: rename to __ns_ref
nsfs: port to ns_ref_*() helpers
net: port to ns_ref_*() helpers
uts: port to ns_ref_*() helpers
ipv4: use check_net()
net: use check_net()
net-sysfs: use check_net()
user: port to ns_ref_*() helpers
time: port to ns_ref_*() helpers
pid: port to ns_ref_*() helpers
ipc: port to ns_ref_*() helpers
cgroup: port to ns_ref_*() helpers
...
Pull misc vfs updates from Christian Brauner:
"This contains the usual selections of misc updates for this cycle.
Features:
- Add "initramfs_options" parameter to set initramfs mount options.
This allows to add specific mount options to the rootfs to e.g.,
limit the memory size
- Add RWF_NOSIGNAL flag for pwritev2()
Add RWF_NOSIGNAL flag for pwritev2. This flag prevents the SIGPIPE
signal from being raised when writing on disconnected pipes or
sockets. The flag is handled directly by the pipe filesystem and
converted to the existing MSG_NOSIGNAL flag for sockets
- Allow to pass pid namespace as procfs mount option
Ever since the introduction of pid namespaces, procfs has had very
implicit behaviour surrounding them (the pidns used by a procfs
mount is auto-selected based on the mounting process's active
pidns, and the pidns itself is basically hidden once the mount has
been constructed)
This implicit behaviour has historically meant that userspace was
required to do some special dances in order to configure the pidns
of a procfs mount as desired. Examples include:
* In order to bypass the mnt_too_revealing() check, Kubernetes
creates a procfs mount from an empty pidns so that user
namespaced containers can be nested (without this, the nested
containers would fail to mount procfs)
But this requires forking off a helper process because you cannot
just one-shot this using mount(2)
* Container runtimes in general need to fork into a container
before configuring its mounts, which can lead to security issues
in the case of shared-pidns containers (a privileged process in
the pidns can interact with your container runtime process)
While SUID_DUMP_DISABLE and user namespaces make this less of an
issue, the strict need for this due to a minor uAPI wart is kind
of unfortunate
Things would be much easier if there was a way for userspace to
just specify the pidns they want. So this pull request contains
changes to implement a new "pidns" argument which can be set
using fsconfig(2):
fsconfig(procfd, FSCONFIG_SET_FD, "pidns", NULL, nsfd);
fsconfig(procfd, FSCONFIG_SET_STRING, "pidns", "/proc/self/ns/pid", 0);
or classic mount(2) / mount(8):
// mount -t proc -o pidns=/proc/self/ns/pid proc /tmp/proc
mount("proc", "/tmp/proc", "proc", MS_..., "pidns=/proc/self/ns/pid");
Cleanups:
- Remove the last references to EXPORT_OP_ASYNC_LOCK
- Make file_remove_privs_flags() static
- Remove redundant __GFP_NOWARN when GFP_NOWAIT is used
- Use try_cmpxchg() in start_dir_add()
- Use try_cmpxchg() in sb_init_done_wq()
- Replace offsetof() with struct_size() in ioctl_file_dedupe_range()
- Remove vfs_ioctl() export
- Replace rwlock() with spinlock in epoll code as rwlock causes
priority inversion on preempt rt kernels
- Make ns_entries in fs/proc/namespaces const
- Use a switch() statement() in init_special_inode() just like we do
in may_open()
- Use struct_size() in dir_add() in the initramfs code
- Use str_plural() in rd_load_image()
- Replace strcpy() with strscpy() in find_link()
- Rename generic_delete_inode() to inode_just_drop() and
generic_drop_inode() to inode_generic_drop()
- Remove unused arguments from fcntl_{g,s}et_rw_hint()
Fixes:
- Document @name parameter for name_contains_dotdot() helper
- Fix spelling mistake
- Always return zero from replace_fd() instead of the file descriptor
number
- Limit the size for copy_file_range() in compat mode to prevent a
signed overflow
- Fix debugfs mount options not being applied
- Verify the inode mode when loading it from disk in minixfs
- Verify the inode mode when loading it from disk in cramfs
- Don't trigger automounts with RESOLVE_NO_XDEV
If openat2() was called with RESOLVE_NO_XDEV it didn't traverse
through automounts, but could still trigger them
- Add FL_RECLAIM flag to show_fl_flags() macro so it appears in
tracepoints
- Fix unused variable warning in rd_load_image() on s390
- Make INITRAMFS_PRESERVE_MTIME depend on BLK_DEV_INITRD
- Use ns_capable_noaudit() when determining net sysctl permissions
- Don't call path_put() under namespace semaphore in listmount() and
statmount()"
* tag 'vfs-6.18-rc1.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: (38 commits)
fcntl: trim arguments
listmount: don't call path_put() under namespace semaphore
statmount: don't call path_put() under namespace semaphore
pid: use ns_capable_noaudit() when determining net sysctl permissions
fs: rename generic_delete_inode() and generic_drop_inode()
init: INITRAMFS_PRESERVE_MTIME should depend on BLK_DEV_INITRD
initramfs: Replace strcpy() with strscpy() in find_link()
initrd: Use str_plural() in rd_load_image()
initramfs: Use struct_size() helper to improve dir_add()
initrd: Fix unused variable warning in rd_load_image() on s390
fs: use the switch statement in init_special_inode()
fs/proc/namespaces: make ns_entries const
filelock: add FL_RECLAIM to show_fl_flags() macro
eventpoll: Replace rwlock with spinlock
selftests/proc: add tests for new pidns APIs
procfs: add "pidns" mount option
pidns: move is-ancestor logic to helper
openat2: don't trigger automounts with RESOLVE_NO_XDEV
namei: move cross-device check to __traverse_mounts
namei: remove LOOKUP_NO_XDEV check from handle_mounts
...
There's a silly problem with the CC_HAS_ASM_GOTO_OUTPUT test: even with
a working compiler it will fail on some architectures simply because it
uses the mnemonic "jmp" for testing the inline asm.
And as reported by Geert, not all architectures use that mnemonic, so
the test fails spuriously on such platforms (including arm and riscv,
but also several other architectures).
This issue avoided any obvious test failures because the build still
works thanks to falling back on the old non-asm-goto code, which just
generates worse code.
Just use an empty asm statement instead.
Reported-and-tested-by: Geert Uytterhoeven <geert@linux-m68k.org>
Suggested-by: Peter Zijlstra <peterz@infradead.org>
Fixes: e2ffa15b9b ("kbuild: Disable CC_HAS_ASM_GOTO_OUTPUT on clang < 17")
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
It's misplaced in struct proc_ns_operations and ns->ops might be NULL if
the namespace is compiled out but we still want to know the type of the
namespace for the initial namespace struct.
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Christian Brauner <brauner@kernel.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>
clang < 17 fails to use scope local labels with CONFIG_CC_HAS_ASM_GOTO_OUTPUT=y:
{
__label__ local_lbl;
...
unsafe_get_user(uval, uaddr, local_lbl);
...
return 0;
local_lbl:
return -EFAULT;
}
when two such scopes exist in the same function:
error: cannot jump from this asm goto statement to one of its possible targets
There are other failure scenarios. Shuffling code around slightly makes it
worse and fail even with one instance.
That issue prevents using local labels for a cleanup based user access
mechanism.
After failed attempts to provide a simple enough test case for the 'depends
on' test in Kconfig, the initial cure was to mark ASM goto broken on clang
versions < 17 to get this road block out of the way.
But Nathan pointed out that this is a known clang issue and indeed affects
clang < version 17 in combination with cleanup(). It's not even required to
use local labels for that.
The clang issue tracker has a small enough test case, which can be used as
a test in the 'depends on' section of CC_HAS_ASM_GOTO_OUTPUT:
void bar(void **);
void* baz(void);
int foo (void) {
{
asm goto("jmp %l0"::::l0);
return 0;
l0:
return 1;
}
void *x __attribute__((cleanup(bar))) = baz();
{
asm goto("jmp %l0"::::l1);
return 42;
l1:
return 0xff;
}
}
Add another dependency to config CC_HAS_ASM_GOTO_OUTPUT for it and use the
clang issue tracker test case for detection by condensing it to obfuscated
C-code contest format. This reliably catches the problem on clang < 17 and
did not show any issues on the non broken GCC versions.
That test might be sufficient to catch all issues and therefore could
replace the existing test, but keeping that around does no harm either.
Thanks to Nathan for pointing to the relevant clang issue!
Suggested-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Nathan Chancellor <nathan@kernel.org>
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
Link: https://github.com/ClangBuiltLinux/linux/issues/1886
Link: f023f5cdb2
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>
Support the generic ns lookup infrastructure to support file handles for
namespaces.
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Christian Brauner <brauner@kernel.org>
Make the statement attribute "assume" with a new __assume macro available.
The assume attribute is used to indicate that a certain condition is
assumed to be true. Compilers may or may not use this indication to
generate optimized code. If this condition is violated at runtime, the
behavior is undefined.
Note that the clang documentation states that optimizers may react
differently to this attribute, and this may even have a negative
performance impact. Therefore this attribute should be used with care.
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
INITRAMFS_PRESERVE_MTIME is only used in init/initramfs.c and
init/initramfs_test.c. Hence add a dependency on BLK_DEV_INITRD, to
prevent asking the user about this feature when configuring a kernel
without initramfs support.
Fixes: 1274aea127 ("initramfs: add INITRAMFS_PRESERVE_MTIME Kconfig option")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Martin Wilck <mwilck@suse.com>
Reviewed-by: David Disseldorp <ddiss@suse.de>
Signed-off-by: Christian Brauner <brauner@kernel.org>
Add the local variable 'nr_disks' and replace the manual ternary "s"
pluralization with the standardized str_plural() helper function.
Use pr_notice() instead of printk(KERN_NOTICE) to silence a checkpatch
warning.
No functional changes intended.
Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Christian Brauner <brauner@kernel.org>
Use struct_size() to calculate the number of bytes to allocate for a new
directory entry. No functional changes.
Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev>
Signed-off-by: Christian Brauner <brauner@kernel.org>
The local variables 'rotator' and 'rotate' (used for the progress
indicator) aren't used on s390. Building the kernel with W=1 generates
the following warning:
init/do_mounts_rd.c:192:17: warning: variable 'rotate' set but not used [-Wunused-but-set-variable]
192 | unsigned short rotate = 0;
| ^
1 warning generated.
Remove the preprocessor directives and use the IS_ENABLED(CONFIG_S390)
macro instead, allowing the compiler to optimize away unused variables
and avoid the warning on s390.
Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev>
Signed-off-by: Christian Brauner <brauner@kernel.org>
