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2025-10-04Merge tag 'printk-for-6.18' of ↵Linus Torvalds1-0/+12
git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux 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
2025-10-02Merge tag 'mm-nonmm-stable-2025-10-02-15-29' of ↵Linus Torvalds1-0/+12
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm 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) ...
2025-10-02Merge branch 'rework/ringbuffer-kunit-test' into for-linusPetr Mladek1-0/+12
2025-10-01Merge tag 'kbuild-6.18-1' of ↵Linus Torvalds1-1/+66
git://git.kernel.org/pub/scm/linux/kernel/git/kbuild/linux Pull Kbuild updates from Nathan Chancellor: - Extend modules.builtin.modinfo to include module aliases from MODULE_DEVICE_TABLE for builtin modules so that userspace tools (such as kmod) can verify that a particular module alias will be handled by a builtin module - Bump the minimum version of LLVM for building the kernel to 15.0.0 - Upgrade several userspace API checks in headers_check.pl to errors - Unify and consolidate CONFIG_WERROR / W=e handling - Turn assembler and linker warnings into errors with CONFIG_WERROR / W=e - Respect CONFIG_WERROR / W=e when building userspace programs (userprogs) - Enable -Werror unconditionally when building host programs (hostprogs) - Support copy_file_range() and data segment alignment in gen_init_cpio to improve performance on filesystems that support reflinks such as btrfs and XFS - Miscellaneous small changes to scripts and configuration files * tag 'kbuild-6.18-1' of git://git.kernel.org/pub/scm/linux/kernel/git/kbuild/linux: (47 commits) modpost: Initialize builtin_modname to stop SIGSEGVs Documentation: kbuild: note CONFIG_DEBUG_EFI in reproducible builds kbuild: vmlinux.unstripped should always depend on .vmlinux.export.o modpost: Create modalias for builtin modules modpost: Add modname to mod_device_table alias scsi: Always define blogic_pci_tbl structure kbuild: extract modules.builtin.modinfo from vmlinux.unstripped kbuild: keep .modinfo section in vmlinux.unstripped kbuild: always create intermediate vmlinux.unstripped s390: vmlinux.lds.S: Reorder sections KMSAN: Remove tautological checks objtool: Drop noinstr hack for KCSAN_WEAK_MEMORY lib/Kconfig.debug: Drop CLANG_VERSION check from DEBUG_INFO_DWARF_TOOLCHAIN_DEFAULT riscv: Remove ld.lld version checks from many TOOLCHAIN_HAS configs riscv: Unconditionally use linker relaxation riscv: Remove version check for LTO_CLANG selects powerpc: Drop unnecessary initializations in __copy_inst_from_kernel_nofault() mips: Unconditionally select ARCH_HAS_CURRENT_STACK_POINTER arm64: Remove tautological LLVM Kconfig conditions ARM: Clean up definition of ARM_HAS_GROUP_RELOCS ...
2025-09-30Merge tag 'timers-vdso-2025-09-29' of ↵Linus Torvalds1-1/+1
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 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
2025-09-30Merge tag 'cgroup-for-6.18' of ↵Linus Torvalds1-0/+3
git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup 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 ...
2025-09-29Merge tag 's390-6.18-1' of ↵Linus Torvalds1-0/+10
git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux 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 ...
2025-09-29Merge tag 'hardening-v6.18-rc1' of ↵Linus Torvalds1-2/+2
git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux Pull hardening updates from Kees Cook: "One notable addition is the creation of the 'transitional' keyword for kconfig so CONFIG renaming can go more smoothly. This has been a long-standing deficiency, and with the renaming of CONFIG_CFI_CLANG to CONFIG_CFI (since GCC will soon have KCFI support), this came up again. The breadth of the diffstat is mainly this renaming. - Clean up usage of TRAILING_OVERLAP() (Gustavo A. R. Silva) - lkdtm: fortify: Fix potential NULL dereference on kmalloc failure (Junjie Cao) - Add str_assert_deassert() helper (Lad Prabhakar) - gcc-plugins: Remove TODO_verify_il for GCC >= 16 - kconfig: Fix BrokenPipeError warnings in selftests - kconfig: Add transitional symbol attribute for migration support - kcfi: Rename CONFIG_CFI_CLANG to CONFIG_CFI" * tag 'hardening-v6.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux: lib/string_choices: Add str_assert_deassert() helper kcfi: Rename CONFIG_CFI_CLANG to CONFIG_CFI kconfig: Add transitional symbol attribute for migration support kconfig: Fix BrokenPipeError warnings in selftests gcc-plugins: Remove TODO_verify_il for GCC >= 16 stddef: Introduce __TRAILING_OVERLAP() stddef: Remove token-pasting in TRAILING_OVERLAP() lkdtm: fortify: Fix potential NULL dereference on kmalloc failure
2025-09-29Merge tag 'namespace-6.18-rc1' of ↵Linus Torvalds2-2/+5
git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs 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 ...
2025-09-29Merge tag 'vfs-6.18-rc1.misc' of ↵Linus Torvalds3-10/+10
git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs 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 ...
2025-09-29Fix CC_HAS_ASM_GOTO_OUTPUT on non-x86 architecturesLinus Torvalds1-1/+1
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: e2ffa15b9baa ("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>
2025-09-25ns: move ns type into struct ns_commonChristian Brauner1-0/+1
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>
2025-09-24kcfi: Rename CONFIG_CFI_CLANG to CONFIG_CFIKees Cook1-2/+2
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>
2025-09-24kbuild: Disable CC_HAS_ASM_GOTO_OUTPUT on clang < 17Thomas Gleixner1-0/+3
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: https://github.com/llvm/llvm-project/commit/f023f5cdb2e6c19026f04a15b5a935c041835d14
2025-09-19Merge 6.17-rc6 into kbuild-nextNathan Chancellor2-5/+9
Commit bd7c2312128e ("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 41f9049cff32 ("riscv: Only allow LTO with CMODEL_MEDANY") and commit 6578a1ff6aa4 ("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>
2025-09-19ns: use inode initializer for initial namespacesChristian Brauner1-1/+1
Just use the common helper we have. Signed-off-by: Christian Brauner <brauner@kernel.org>
2025-09-19ns: rename to __ns_refChristian Brauner1-1/+1
Make it easier to grep and rename to ns_count. Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Christian Brauner <brauner@kernel.org>
2025-09-19time: support ns lookupChristian Brauner1-0/+2
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>
2025-09-18compiler_types: Add __assume macroHeiko Carstens1-0/+10
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>
2025-09-15init: INITRAMFS_PRESERVE_MTIME should depend on BLK_DEV_INITRDGeert Uytterhoeven1-0/+1
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: 1274aea127b2e8c9 ("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>
2025-09-15initramfs: Replace strcpy() with strscpy() in find_link()Thorsten Blum1-1/+1
strcpy() is deprecated; use strscpy() instead. Link: https://github.com/KSPP/linux/issues/88 Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev> Reviewed-by: Justin Stitt <justinstitt@google.com> Signed-off-by: Christian Brauner <brauner@kernel.org>
2025-09-15initrd: Use str_plural() in rd_load_image()Thorsten Blum1-3/+5
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>
2025-09-15initramfs: Use struct_size() helper to improve dir_add()Thorsten Blum1-1/+2
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>
2025-09-15initrd: Fix unused variable warning in rd_load_image() on s390Thorsten Blum1-5/+1
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>
2025-09-13init: handle bootloader identifier in kernel parametersHuacai Chen1-0/+12
BootLoaders (Grub, LILO, etc) may pass an identifier such as "BOOT_IMAGE= /boot/vmlinuz-x.y.z" to kernel parameters. But these identifiers are not recognized by the kernel itself so will be passed to userspace. However user space init program also don't recognize it. KEXEC/KDUMP (kexec-tools) may also pass an identifier such as "kexec" on some architectures. We cannot change BootLoader's behavior, because this behavior exists for many years, and there are already user space programs search BOOT_IMAGE= in /proc/cmdline to obtain the kernel image locations: https://github.com/linuxdeepin/deepin-ab-recovery/blob/master/util.go (search getBootOptions) https://github.com/linuxdeepin/deepin-ab-recovery/blob/master/main.go (search getKernelReleaseWithBootOption) So the the best way is handle (ignore) it by the kernel itself, which can avoid such boot warnings (if we use something like init=/bin/bash, bootloader identifier can even cause a crash): Kernel command line: BOOT_IMAGE=(hd0,1)/vmlinuz-6.x root=/dev/sda3 ro console=tty Unknown kernel command line parameters "BOOT_IMAGE=(hd0,1)/vmlinuz-6.x", will be passed to user space. [chenhuacai@loongson.cn: use strstarts()] Link: https://lkml.kernel.org/r/20250815090120.1569947-1-chenhuacai@loongson.cn Link: https://lkml.kernel.org/r/20250721101343.3283480-1-chenhuacai@loongson.cn Signed-off-by: Huacai Chen <chenhuacai@loongson.cn> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Christian Brauner <brauner@kernel.org> Cc: Jan Kara <jack@suse.cz> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-09-10Merge tag 'mm-hotfixes-stable-2025-09-10-20-00' of ↵Linus Torvalds1-1/+1
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Pull misc fixes from Andrew Morton: "20 hotfixes. 15 are cc:stable and the remainder address post-6.16 issues or aren't considered necessary for -stable kernels. 14 of these fixes are for MM. This includes - kexec fixes from Breno for a recently introduced use-uninitialized bug - DAMON fixes from Quanmin Yan to avoid div-by-zero crashes which can occur if the operator uses poorly-chosen insmod parameters and misc singleton fixes" * tag 'mm-hotfixes-stable-2025-09-10-20-00' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: MAINTAINERS: add tree entry to numa memblocks and emulation block mm/damon/sysfs: fix use-after-free in state_show() proc: fix type confusion in pde_set_flags() compiler-clang.h: define __SANITIZE_*__ macros only when undefined mm/vmalloc, mm/kasan: respect gfp mask in kasan_populate_vmalloc() ocfs2: fix recursive semaphore deadlock in fiemap call mm/memory-failure: fix VM_BUG_ON_PAGE(PagePoisoned(page)) when unpoison memory mm/mremap: fix regression in vrm->new_addr check percpu: fix race on alloc failed warning limit mm/memory-failure: fix redundant updates for already poisoned pages s390: kexec: initialize kexec_buf struct riscv: kexec: initialize kexec_buf struct arm64: kexec: initialize kexec_buf struct in load_other_segments() mm/damon/reclaim: avoid divide-by-zero in damon_reclaim_apply_parameters() mm/damon/lru_sort: avoid divide-by-zero in damon_lru_sort_apply_parameters() mm/damon/core: set quota->charged_from to jiffies at first charge window mm/hugetlb: add missing hugetlb_lock in __unmap_hugepage_range() init/main.c: fix boot time tracing crash mm/memory_hotplug: fix hwpoisoned large folio handling in do_migrate_range() mm/khugepaged: fix the address passed to notifier on testing young
2025-09-10cgroup: replace global percpu_rwsem with per threadgroup resem when writing ↵Yi Tao1-0/+3
to cgroup.procs The static usage pattern of creating a cgroup, enabling controllers, and then seeding it with CLONE_INTO_CGROUP doesn't require write locking cgroup_threadgroup_rwsem and thus doesn't benefit from this patch. To avoid affecting other users, the per threadgroup rwsem is only used when the favordynmods is enabled. As computer hardware advances, modern systems are typically equipped with many CPU cores and large amounts of memory, enabling the deployment of numerous applications. On such systems, container creation and deletion become frequent operations, making cgroup process migration no longer a cold path. This leads to noticeable contention with common process operations such as fork, exec, and exit. To alleviate the contention between cgroup process migration and operations like process fork, this patch modifies lock to take the write lock on signal_struct->group_rwsem when writing pid to cgroup.procs/threads instead of holding a global write lock. Cgroup process migration has historically relied on signal_struct->group_rwsem to protect thread group integrity. In commit <1ed1328792ff> ("sched, cgroup: replace signal_struct->group_rwsem with a global percpu_rwsem"), this was changed to a global cgroup_threadgroup_rwsem. The advantage of using a global lock was simplified handling of process group migrations. This patch retains the use of the global lock for protecting process group migration, while reducing contention by using per thread group lock during cgroup.procs/threads writes. The locking behavior is as follows: write cgroup.procs/threads | process fork,exec,exit | process group migration ------------------------------------------------------------------------------ cgroup_lock() | down_read(&g_rwsem) | cgroup_lock() down_write(&p_rwsem) | down_read(&p_rwsem) | down_write(&g_rwsem) critical section | critical section | critical section up_write(&p_rwsem) | up_read(&p_rwsem) | up_write(&g_rwsem) cgroup_unlock() | up_read(&g_rwsem) | cgroup_unlock() g_rwsem denotes cgroup_threadgroup_rwsem, p_rwsem denotes signal_struct->group_rwsem. This patch eliminates contention between cgroup migration and fork operations for threads that belong to different thread groups, thereby reducing the long-tail latency of cgroup migrations and lowering system load. With this patch, under heavy fork and exec interference, the long-tail latency of cgroup migration has been reduced from milliseconds to microseconds. Under heavy cgroup migration interference, the multi-CPU score of the spawn test case in UnixBench increased by 9%. tj: Update comment in cgroup_favor_dynmods() and switch WARN_ONCE() to pr_warn_once(). Signed-off-by: Yi Tao <escape@linux.alibaba.com> Signed-off-by: Tejun Heo <tj@kernel.org>
2025-09-06Merge tag 'rust-fixes-6.17-2' of ↵Linus Torvalds1-0/+3
git://git.kernel.org/pub/scm/linux/kernel/git/ojeda/linux Pull rust fixes from Miguel Ojeda: - Two changes to prepare for the future Rust 1.91.0 release (expected 2025-10-30, currently in nightly): a target specification format change and a renamed, soon-to-be-stabilized 'core' function. * tag 'rust-fixes-6.17-2' of git://git.kernel.org/pub/scm/linux/kernel/git/ojeda/linux: rust: support Rust >= 1.91.0 target spec rust: use the new name Location::file_as_c_str() in Rust >= 1.91.0
2025-09-04vdso: Drop Kconfig GENERIC_VDSO_TIME_NSThomas Weißschuh1-1/+1
All architectures implementing time-related functionality in the vDSO are using the generic vDSO library which handles time namespaces properly. Remove the now unnecessary Kconfig symbol. Enables the use of time namespaces on architectures, which use the generic vDSO but did not enable GENERIC_VDSO_TIME_NS, namely MIPS and arm. Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Link: https://lore.kernel.org/all/20250826-vdso-cleanups-v1-10-d9b65750e49f@linutronix.de
2025-09-03init/main.c: fix boot time tracing crashMike Rapoport (Microsoft)1-1/+1
Steven Rostedt reported a crash with "ftrace=function" kernel command line: [ 0.159269] BUG: kernel NULL pointer dereference, address: 000000000000001c [ 0.160254] #PF: supervisor read access in kernel mode [ 0.160975] #PF: error_code(0x0000) - not-present page [ 0.161697] PGD 0 P4D 0 [ 0.162055] Oops: Oops: 0000 [#1] SMP PTI [ 0.162619] CPU: 0 UID: 0 PID: 0 Comm: swapper Not tainted 6.17.0-rc2-test-00006-g48d06e78b7cb-dirty #9 PREEMPT(undef) [ 0.164141] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 [ 0.165439] RIP: 0010:kmem_cache_alloc_noprof (mm/slub.c:4237) [ 0.166186] Code: 90 90 90 f3 0f 1e fa 0f 1f 44 00 00 55 48 89 e5 41 57 41 56 41 55 41 54 49 89 fc 53 48 83 e4 f0 48 83 ec 20 8b 05 c9 b6 7e 01 <44> 8b 77 1c 65 4c 8b 2d b5 ea 20 02 4c 89 6c 24 18 41 89 f5 21 f0 [ 0.168811] RSP: 0000:ffffffffb2e03b30 EFLAGS: 00010086 [ 0.169545] RAX: 0000000001fff33f RBX: 0000000000000000 RCX: 0000000000000000 [ 0.170544] RDX: 0000000000002800 RSI: 0000000000002800 RDI: 0000000000000000 [ 0.171554] RBP: ffffffffb2e03b80 R08: 0000000000000004 R09: ffffffffb2e03c90 [ 0.172549] R10: ffffffffb2e03c90 R11: 0000000000000000 R12: 0000000000000000 [ 0.173544] R13: ffffffffb2e03c90 R14: ffffffffb2e03c90 R15: 0000000000000001 [ 0.174542] FS: 0000000000000000(0000) GS:ffff9d2808114000(0000) knlGS:0000000000000000 [ 0.175684] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 0.176486] CR2: 000000000000001c CR3: 000000007264c001 CR4: 00000000000200b0 [ 0.177483] Call Trace: [ 0.177828] <TASK> [ 0.178123] mas_alloc_nodes (lib/maple_tree.c:176 (discriminator 2) lib/maple_tree.c:1255 (discriminator 2)) [ 0.178692] mas_store_gfp (lib/maple_tree.c:5468) [ 0.179223] execmem_cache_add_locked (mm/execmem.c:207) [ 0.179870] execmem_alloc (mm/execmem.c:213 mm/execmem.c:313 mm/execmem.c:335 mm/execmem.c:475) [ 0.180397] ? ftrace_caller (arch/x86/kernel/ftrace_64.S:169) [ 0.180922] ? __pfx_ftrace_caller (arch/x86/kernel/ftrace_64.S:158) [ 0.181517] execmem_alloc_rw (mm/execmem.c:487) [ 0.182052] arch_ftrace_update_trampoline (arch/x86/kernel/ftrace.c:266 arch/x86/kernel/ftrace.c:344 arch/x86/kernel/ftrace.c:474) [ 0.182778] ? ftrace_caller_op_ptr (arch/x86/kernel/ftrace_64.S:182) [ 0.183388] ftrace_update_trampoline (kernel/trace/ftrace.c:7947) [ 0.184024] __register_ftrace_function (kernel/trace/ftrace.c:368) [ 0.184682] ftrace_startup (kernel/trace/ftrace.c:3048) [ 0.185205] ? __pfx_function_trace_call (kernel/trace/trace_functions.c:210) [ 0.185877] register_ftrace_function_nolock (kernel/trace/ftrace.c:8717) [ 0.186595] register_ftrace_function (kernel/trace/ftrace.c:8745) [ 0.187254] ? __pfx_function_trace_call (kernel/trace/trace_functions.c:210) [ 0.187924] function_trace_init (kernel/trace/trace_functions.c:170) [ 0.188499] tracing_set_tracer (kernel/trace/trace.c:5916 kernel/trace/trace.c:6349) [ 0.189088] register_tracer (kernel/trace/trace.c:2391) [ 0.189642] early_trace_init (kernel/trace/trace.c:11075 kernel/trace/trace.c:11149) [ 0.190204] start_kernel (init/main.c:970) [ 0.190732] x86_64_start_reservations (arch/x86/kernel/head64.c:307) [ 0.191381] x86_64_start_kernel (??:?) [ 0.191955] common_startup_64 (arch/x86/kernel/head_64.S:419) [ 0.192534] </TASK> [ 0.192839] Modules linked in: [ 0.193267] CR2: 000000000000001c [ 0.193730] ---[ end trace 0000000000000000 ]--- The crash happens because on x86 ftrace allocations from execmem require maple tree to be initialized. Move maple tree initialization that depends only on slab availability earlier in boot so that it will happen right after mm_core_init(). Link: https://lkml.kernel.org/r/20250824130759.1732736-1-rppt@kernel.org Fixes: 5d79c2be5081 ("x86/ftrace: enable EXECMEM_ROX_CACHE for ftrace allocations") Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org> Reported-by: Steven Rostedt (Google) <rostedt@goodmis.org> Tested-by: Steven Rostedt (Google) <rostedt@goodmis.org> Closes: https://lore.kernel.org/all/20250820184743.0302a8b5@gandalf.local.home/ Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Reviewed-by: Liam R. Howlett <Liam.Howlett@oracle.com> Cc: Borislav Betkov <bp@alien8.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleinxer <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-08-31rust: use the new name Location::file_as_c_str() in Rust >= 1.91.0Alice Ryhl1-0/+3
As part of the stabilization of Location::file_with_nul(), it was brought up that the with_nul() suffix usually means something else in Rust APIs, so the API is being renamed prior to stabilization [1]. Thus, use the new name on new rustc versions. Link: https://www.github.com/rust-lang/rust/pull/145928 [1] Signed-off-by: Alice Ryhl <aliceryhl@google.com> Reviewed-by: Boqun Feng <boqun.feng@gmail.com> Link: https://lore.kernel.org/r/20250827-file_as_c_str-v1-1-d3f5a3916a9c@google.com [ Kept `cfg` separation. Reworded slightly. - Miguel ] Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2025-08-29hardening: Require clang 20.1.0 for __counted_byNathan Chancellor1-4/+5
After an innocuous change in -next that modified a structure that contains __counted_by, clang-19 start crashing when building certain files in drivers/gpu/drm/xe. When assertions are enabled, the more descriptive failure is: clang: clang/lib/AST/RecordLayoutBuilder.cpp:3335: const ASTRecordLayout &clang::ASTContext::getASTRecordLayout(const RecordDecl *) const: Assertion `D && "Cannot get layout of forward declarations!"' failed. According to a reverse bisect, a tangential change to the LLVM IR generation phase of clang during the LLVM 20 development cycle [1] resolves this problem. Bump the version of clang that enables CONFIG_CC_HAS_COUNTED_BY to 20.1.0 to ensure that this issue cannot be hit. Link: https://github.com/llvm/llvm-project/commit/160fb1121cdf703c3ef5e61fb26c5659eb581489 [1] Signed-off-by: Nathan Chancellor <nathan@kernel.org> Reviewed-by: Justin Stitt <justinstitt@google.com> Link: https://lore.kernel.org/r/20250807-fix-counted_by-clang-19-v1-1-902c86c1d515@kernel.org Signed-off-by: Kees Cook <kees@kernel.org>
2025-08-21initramfs_test: add filename padding test caseDavid Disseldorp1-1/+66
Confirm that cpio filenames with multiple trailing zeros (accounted for in namesize) extract successfully. Signed-off-by: David Disseldorp <ddiss@suse.de> Acked-by: Nicolas Schier <nsc@kernel.org> Link: https://lore.kernel.org/r/20250819032607.28727-9-ddiss@suse.de [nathan: Fix duplicate filesize initialization, reported at https://lore.kernel.org/202508200304.wF1u78il-lkp@intel.com/] Signed-off-by: Nathan Chancellor <nathan@kernel.org>
2025-08-03Merge tag 'mm-nonmm-stable-2025-08-03-12-47' of ↵Linus Torvalds2-1/+9
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Pull non-MM updates from Andrew Morton: "Significant patch series in this pull request: - "squashfs: Remove page->mapping references" (Matthew Wilcox) gets us closer to being able to remove page->mapping - "relayfs: misc changes" (Jason Xing) does some maintenance and minor feature addition work in relayfs - "kdump: crashkernel reservation from CMA" (Jiri Bohac) switches us from static preallocation of the kdump crashkernel's working memory over to dynamic allocation. So the difficulty of a-priori estimation of the second kernel's needs is removed and the first kernel obtains extra memory - "generalize panic_print's dump function to be used by other kernel parts" (Feng Tang) implements some consolidation and rationalization of the various ways in which a failing kernel splats information at the operator * tag 'mm-nonmm-stable-2025-08-03-12-47' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (80 commits) tools/getdelays: add backward compatibility for taskstats version kho: add test for kexec handover delaytop: enhance error logging and add PSI feature description samples: Kconfig: fix spelling mistake "instancess" -> "instances" fat: fix too many log in fat_chain_add() scripts/spelling.txt: add notifer||notifier to spelling.txt xen/xenbus: fix typo "notifer" net: mvneta: fix typo "notifer" drm/xe: fix typo "notifer" cxl: mce: fix typo "notifer" KVM: x86: fix typo "notifer" MAINTAINERS: add maintainers for delaytop ucount: use atomic_long_try_cmpxchg() in atomic_long_inc_below() ucount: fix atomic_long_inc_below() argument type kexec: enable CMA based contiguous allocation stackdepot: make max number of pools boot-time configurable lib/xxhash: remove unused functions init/Kconfig: restore CONFIG_BROKEN help text lib/raid6: update recov_rvv.c zero page usage docs: update docs after introducing delaytop ...
2025-08-02init/Kconfig: restore CONFIG_BROKEN help textAndrew Morton1-0/+4
Linus added it in 2003, it later was removed. Put it back. Cc: Anshuman Khandual <anshuman.khandual@arm.com> Cc: Borislav Betkov <bp@alien8.de> Cc: David S. Miller <davem@davemloft.net> Cc: Ingo Molnar <mingo@redhat.com> Cc: Thomas Gleinxer <tglx@linutronix.de> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-07-31Merge tag 'sched_ext-for-6.17' of ↵Linus Torvalds1-0/+5
git://git.kernel.org/pub/scm/linux/kernel/git/tj/sched_ext Pull sched_ext updates from Tejun Heo: - Add support for cgroup "cpu.max" interface - Code organization cleanup so that ext_idle.c doesn't depend on the source-file-inclusion build method of sched/ - Drop UP paths in accordance with sched core changes - Documentation and other misc changes * tag 'sched_ext-for-6.17' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/sched_ext: sched_ext: Fix scx_bpf_reenqueue_local() reference sched_ext: Drop kfuncs marked for removal in 6.15 sched_ext, rcu: Eject BPF scheduler on RCU CPU stall panic kernel/sched/ext.c: fix typo "occured" -> "occurred" in comments sched_ext: Add support for cgroup bandwidth control interface sched_ext, sched/core: Factor out struct scx_task_group sched_ext: Return NULL in llc_span sched_ext: Always use SMP versions in kernel/sched/ext_idle.h sched_ext: Always use SMP versions in kernel/sched/ext_idle.c sched_ext: Always use SMP versions in kernel/sched/ext.h sched_ext: Always use SMP versions in kernel/sched/ext.c sched_ext: Documentation: Clarify time slice handling in task lifecycle sched_ext: Make scx_locked_rq() inline sched_ext: Make scx_rq_bypassing() inline sched_ext: idle: Make local functions static in ext_idle.c sched_ext: idle: Remove unnecessary ifdef in scx_bpf_cpu_node()
2025-07-31Merge tag 'mm-stable-2025-07-30-15-25' of ↵Linus Torvalds1-0/+1
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Pull MM updates from Andrew Morton: "As usual, many cleanups. The below blurbiage describes 42 patchsets. 21 of those are partially or fully cleanup work. "cleans up", "cleanup", "maintainability", "rationalizes", etc. I never knew the MM code was so dirty. "mm: ksm: prevent KSM from breaking merging of new VMAs" (Lorenzo Stoakes) addresses an issue with KSM's PR_SET_MEMORY_MERGE mode: newly mapped VMAs were not eligible for merging with existing adjacent VMAs. "mm/damon: introduce DAMON_STAT for simple and practical access monitoring" (SeongJae Park) adds a new kernel module which simplifies the setup and usage of DAMON in production environments. "stop passing a writeback_control to swap/shmem writeout" (Christoph Hellwig) is a cleanup to the writeback code which removes a couple of pointers from struct writeback_control. "drivers/base/node.c: optimization and cleanups" (Donet Tom) contains largely uncorrelated cleanups to the NUMA node setup and management code. "mm: userfaultfd: assorted fixes and cleanups" (Tal Zussman) does some maintenance work on the userfaultfd code. "Readahead tweaks for larger folios" (Ryan Roberts) implements some tuneups for pagecache readahead when it is reading into order>0 folios. "selftests/mm: Tweaks to the cow test" (Mark Brown) provides some cleanups and consistency improvements to the selftests code. "Optimize mremap() for large folios" (Dev Jain) does that. A 37% reduction in execution time was measured in a memset+mremap+munmap microbenchmark. "Remove zero_user()" (Matthew Wilcox) expunges zero_user() in favor of the more modern memzero_page(). "mm/huge_memory: vmf_insert_folio_*() and vmf_insert_pfn_pud() fixes" (David Hildenbrand) addresses some warts which David noticed in the huge page code. These were not known to be causing any issues at this time. "mm/damon: use alloc_migrate_target() for DAMOS_MIGRATE_{HOT,COLD" (SeongJae Park) provides some cleanup and consolidation work in DAMON. "use vm_flags_t consistently" (Lorenzo Stoakes) uses vm_flags_t in places where we were inappropriately using other types. "mm/memfd: Reserve hugetlb folios before allocation" (Vivek Kasireddy) increases the reliability of large page allocation in the memfd code. "mm: Remove pXX_devmap page table bit and pfn_t type" (Alistair Popple) removes several now-unneeded PFN_* flags. "mm/damon: decouple sysfs from core" (SeongJae Park) implememnts some cleanup and maintainability work in the DAMON sysfs layer. "madvise cleanup" (Lorenzo Stoakes) does quite a lot of cleanup/maintenance work in the madvise() code. "madvise anon_name cleanups" (Vlastimil Babka) provides additional cleanups on top or Lorenzo's effort. "Implement numa node notifier" (Oscar Salvador) creates a standalone notifier for NUMA node memory state changes. Previously these were lumped under the more general memory on/offline notifier. "Make MIGRATE_ISOLATE a standalone bit" (Zi Yan) cleans up the pageblock isolation code and fixes a potential issue which doesn't seem to cause any problems in practice. "selftests/damon: add python and drgn based DAMON sysfs functionality tests" (SeongJae Park) adds additional drgn- and python-based DAMON selftests which are more comprehensive than the existing selftest suite. "Misc rework on hugetlb faulting path" (Oscar Salvador) fixes a rather obscure deadlock in the hugetlb fault code and follows that fix with a series of cleanups. "cma: factor out allocation logic from __cma_declare_contiguous_nid" (Mike Rapoport) rationalizes and cleans up the highmem-specific code in the CMA allocator. "mm/migration: rework movable_ops page migration (part 1)" (David Hildenbrand) provides cleanups and future-preparedness to the migration code. "mm/damon: add trace events for auto-tuned monitoring intervals and DAMOS quota" (SeongJae Park) adds some tracepoints to some DAMON auto-tuning code. "mm/damon: fix misc bugs in DAMON modules" (SeongJae Park) does that. "mm/damon: misc cleanups" (SeongJae Park) also does what it claims. "mm: folio_pte_batch() improvements" (David Hildenbrand) cleans up the large folio PTE batching code. "mm/damon/vaddr: Allow interleaving in migrate_{hot,cold} actions" (SeongJae Park) facilitates dynamic alteration of DAMON's inter-node allocation policy. "Remove unmap_and_put_page()" (Vishal Moola) provides a couple of page->folio conversions. "mm: per-node proactive reclaim" (Davidlohr Bueso) implements a per-node control of proactive reclaim - beyond the current memcg-based implementation. "mm/damon: remove damon_callback" (SeongJae Park) replaces the damon_callback interface with a more general and powerful damon_call()+damos_walk() interface. "mm/mremap: permit mremap() move of multiple VMAs" (Lorenzo Stoakes) implements a number of mremap cleanups (of course) in preparation for adding new mremap() functionality: newly permit the remapping of multiple VMAs when the user is specifying MREMAP_FIXED. It still excludes some specialized situations where this cannot be performed reliably. "drop hugetlb_free_pgd_range()" (Anthony Yznaga) switches some sparc hugetlb code over to the generic version and removes the thus-unneeded hugetlb_free_pgd_range(). "mm/damon/sysfs: support periodic and automated stats update" (SeongJae Park) augments the present userspace-requested update of DAMON sysfs monitoring files. Automatic update is now provided, along with a tunable to control the update interval. "Some randome fixes and cleanups to swapfile" (Kemeng Shi) does what is claims. "mm: introduce snapshot_page" (Luiz Capitulino and David Hildenbrand) provides (and uses) a means by which debug-style functions can grab a copy of a pageframe and inspect it locklessly without tripping over the races inherent in operating on the live pageframe directly. "use per-vma locks for /proc/pid/maps reads" (Suren Baghdasaryan) addresses the large contention issues which can be triggered by reads from that procfs file. Latencies are reduced by more than half in some situations. The series also introduces several new selftests for the /proc/pid/maps interface. "__folio_split() clean up" (Zi Yan) cleans up __folio_split()! "Optimize mprotect() for large folios" (Dev Jain) provides some quite large (>3x) speedups to mprotect() when dealing with large folios. "selftests/mm: reuse FORCE_READ to replace "asm volatile("" : "+r" (XXX));" and some cleanup" (wang lian) does some cleanup work in the selftests code. "tools/testing: expand mremap testing" (Lorenzo Stoakes) extends the mremap() selftest in several ways, including adding more checking of Lorenzo's recently added "permit mremap() move of multiple VMAs" feature. "selftests/damon/sysfs.py: test all parameters" (SeongJae Park) extends the DAMON sysfs interface selftest so that it tests all possible user-requested parameters. Rather than the present minimal subset" * tag 'mm-stable-2025-07-30-15-25' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (370 commits) MAINTAINERS: add missing headers to mempory policy & migration section MAINTAINERS: add missing file to cgroup section MAINTAINERS: add MM MISC section, add missing files to MISC and CORE MAINTAINERS: add missing zsmalloc file MAINTAINERS: add missing files to page alloc section MAINTAINERS: add missing shrinker files MAINTAINERS: move memremap.[ch] to hotplug section MAINTAINERS: add missing mm_slot.h file THP section MAINTAINERS: add missing interval_tree.c to memory mapping section MAINTAINERS: add missing percpu-internal.h file to per-cpu section mm/page_alloc: remove trace_mm_alloc_contig_migrate_range_info() selftests/damon: introduce _common.sh to host shared function selftests/damon/sysfs.py: test runtime reduction of DAMON parameters selftests/damon/sysfs.py: test non-default parameters runtime commit selftests/damon/sysfs.py: generalize DAMON context commit assertion selftests/damon/sysfs.py: generalize monitoring attributes commit assertion selftests/damon/sysfs.py: generalize DAMOS schemes commit assertion selftests/damon/sysfs.py: test DAMOS filters commitment selftests/damon/sysfs.py: generalize DAMOS scheme commit assertion selftests/damon/sysfs.py: test DAMOS destinations commitment ...
2025-07-29Merge tag 'x86-boot-2025-07-29' of ↵Linus Torvalds1-5/+0
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 boot updates from Ingo Molnar: - Implement support for embedding EFI SBAT data (Secure Boot Advanced Targeting: a secure boot image revocation facility) on x86 (Vitaly Kuznetsov) - Move the efi_enter_virtual_mode() initialization call from the generic init code to x86 init code (Alexander Shishkin) * tag 'x86-boot-2025-07-29' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/efi: Implement support for embedding SBAT data for x86 x86/efi: Move runtime service initialization to arch/x86
2025-07-29Merge tag 'sched-core-2025-07-28' of ↵Linus Torvalds1-0/+15
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull scheduler updates from Ingo Molnar: "Core scheduler changes: - Better tracking of maximum lag of tasks in presence of different slices duration, for better handling of lag in the fair scheduler (Vincent Guittot) - Clean up and standardize #if/#else/#endif markers throughout the entire scheduler code base (Ingo Molnar) - Make SMP unconditional: build the SMP scheduler's data structures and logic on UP kernel too, even though they are not used, to simplify the scheduler and remove around 200 #ifdef/[#else]/#endif blocks from the scheduler (Ingo Molnar) - Reorganize cgroup bandwidth control interface handling for better interfacing with sched_ext (Tejun Heo) Balancing: - Bump sd->max_newidle_lb_cost when newidle balance fails (Chris Mason) - Remove sched_domain_topology_level::flags to simplify the code (Prateek Nayak) - Simplify and clean up build_sched_topology() (Li Chen) - Optimize build_sched_topology() on large machines (Li Chen) Real-time scheduling: - Add initial version of proxy execution: a mechanism for mutex-owning tasks to inherit the scheduling context of higher priority waiters. Currently limited to a single runqueue and conditional on CONFIG_EXPERT, and other limitations (John Stultz, Peter Zijlstra, Valentin Schneider) - Deadline scheduler (Juri Lelli): - Fix dl_servers initialization order (Juri Lelli) - Fix DL scheduler's root domain reinitialization logic (Juri Lelli) - Fix accounting bugs after global limits change (Juri Lelli) - Fix scalability regression by implementing less agressive dl_server handling (Peter Zijlstra) PSI: - Improve scalability by optimizing psi_group_change() cpu_clock() usage (Peter Zijlstra) Rust changes: - Make Task, CondVar and PollCondVar methods inline to avoid unnecessary function calls (Kunwu Chan, Panagiotis Foliadis) - Add might_sleep() support for Rust code: Rust's "#[track_caller]" mechanism is used so that Rust's might_sleep() doesn't need to be defined as a macro (Fujita Tomonori) - Introduce file_from_location() (Boqun Feng) Debugging & instrumentation: - Make clangd usable with scheduler source code files again (Peter Zijlstra) - tools: Add root_domains_dump.py which dumps root domains info (Juri Lelli) - tools: Add dl_bw_dump.py for printing bandwidth accounting info (Juri Lelli) Misc cleanups & fixes: - Remove play_idle() (Feng Lee) - Fix check_preemption_disabled() (Sebastian Andrzej Siewior) - Do not call __put_task_struct() on RT if pi_blocked_on is set (Luis Claudio R. Goncalves) - Correct the comment in place_entity() (wang wei)" * tag 'sched-core-2025-07-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (84 commits) sched/idle: Remove play_idle() sched: Do not call __put_task_struct() on rt if pi_blocked_on is set sched: Start blocked_on chain processing in find_proxy_task() sched: Fix proxy/current (push,pull)ability sched: Add an initial sketch of the find_proxy_task() function sched: Fix runtime accounting w/ split exec & sched contexts sched: Move update_curr_task logic into update_curr_se locking/mutex: Add p->blocked_on wrappers for correctness checks locking/mutex: Rework task_struct::blocked_on sched: Add CONFIG_SCHED_PROXY_EXEC & boot argument to enable/disable sched/topology: Remove sched_domain_topology_level::flags x86/smpboot: avoid SMT domain attach/destroy if SMT is not enabled x86/smpboot: moves x86_topology to static initialize and truncate x86/smpboot: remove redundant CONFIG_SCHED_SMT smpboot: introduce SDTL_INIT() helper to tidy sched topology setup tools/sched: Add dl_bw_dump.py for printing bandwidth accounting info tools/sched: Add root_domains_dump.py which dumps root domains info sched/deadline: Fix accounting after global limits change sched/deadline: Reset extra_bw to max_bw when clearing root domains sched/deadline: Initialize dl_servers after SMP ...
2025-07-29Merge tag 'locking-futex-2025-07-29' of ↵Linus Torvalds1-4/+0
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull futex updates from Thomas Gleixner: - Switch the reference counting to a RCU based per-CPU reference to address a performance bottleneck vs the single instance rcuref variant - Make the futex selftest build on 32-bit architectures which only support 64-bit time_t, e.g. RISCV-32 - Cleanups and improvements in selftests and futex bench * tag 'locking-futex-2025-07-29' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: selftests/futex: Fix spelling mistake "Succeffuly" -> "Successfully" selftests/futex: Define SYS_futex on 32-bit architectures with 64-bit time_t perf bench futex: Remove support for IMMUTABLE selftests/futex: Remove support for IMMUTABLE futex: Remove support for IMMUTABLE futex: Make futex_private_hash_get() static futex: Use RCU-based per-CPU reference counting instead of rcuref_t selftests/futex: Adapt the private hash test to RCU related changes
2025-07-29Merge tag 'char-misc-6.17-rc1' of ↵Linus Torvalds1-7/+0
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc Pull char / misc / IIO / other driver updates from Greg KH: "Here is the big set of char/misc/iio and other smaller driver subsystems for 6.17-rc1. It's a big set this time around, with the huge majority being in the iio subsystem with new drivers and dts files being added there. Highlights include: - IIO driver updates, additions, and changes making more code const and cleaning up some init logic - bus_type constant conversion changes - misc device test functions added - rust miscdevice minor fixup - unused function removals for some drivers - mei driver updates - mhi driver updates - interconnect driver updates - Android binder updates and test infrastructure added - small cdx driver updates - small comedi fixes - small nvmem driver updates - small pps driver updates - some acrn virt driver fixes for printk messages - other small driver updates All of these have been in linux-next with no reported issues" * tag 'char-misc-6.17-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: (292 commits) binder: Use seq_buf in binder_alloc kunit tests binder: Add copyright notice to new kunit files misc: ti_fpc202: Switch to of_fwnode_handle() bus: moxtet: Use dev_fwnode() pc104: move PC104 option to drivers/Kconfig drivers: virt: acrn: Don't use %pK through printk comedi: fix race between polling and detaching interconnect: qcom: Add Milos interconnect provider driver dt-bindings: interconnect: document the RPMh Network-On-Chip Interconnect in Qualcomm Milos SoC mei: more prints with client prefix mei: bus: use cldev in prints bus: mhi: host: pci_generic: Add Telit FN990B40 modem support bus: mhi: host: Detect events pointing to unexpected TREs bus: mhi: host: pci_generic: Add Foxconn T99W696 modem bus: mhi: host: Use str_true_false() helper bus: mhi: host: pci_generic: Add support for EM929x and set MRU to 32768 for better performance. bus: mhi: host: Fix endianness of BHI vector table bus: mhi: host: pci_generic: Disable runtime PM for QDU100 bus: mhi: host: pci_generic: Fix the modem name of Foxconn T99W640 dt-bindings: interconnect: qcom,msm8998-bwmon: Allow 'nonposted-mmio' ...
2025-07-28Merge tag 'for-6.17/io_uring-20250728' of git://git.kernel.dk/linuxLinus Torvalds1-1/+12
Pull io_uring updates from Jens Axboe: - Optimization to avoid reference counts on non-cloned registered buffers. This is how these buffers were handled prior to having cloning support, and we can still use that approach as long as the buffers haven't been cloned to another ring. - Cleanup and improvement for uring_cmd, where btrfs was the only user of storing allocated data for the lifetime of the uring_cmd. Clean that up so we can get rid of the need to do that. - Avoid unnecessary memory copies in uring_cmd usage. This is particularly important as a lot of uring_cmd usage necessitates the use of 128b SQEs. - A few updates for recv multishot, where it's now possible to add fairness limits for limiting how much is transferred for each retry loop. Additionally, recv multishot now supports an overall cap as well, where once reached the multishot recv will terminate. The latter is useful for buffer management and juggling many recv streams at the same time. - Add support for returning the TX timestamps via a new socket command. This feature can work in either singleshot or multishot mode, where the latter triggers a completion whenever new timestamps are available. This is an alternative to using the existing error queue. - Add support for an io_uring "mock" file, which is the start of being able to do 100% targeted testing in terms of exercising io_uring request handling. The idea is to have a file type that can be anything the tester would like, and behave exactly how you want it to behave in terms of hitting the code paths you want. - Improve zcrx by using sgtables to de-duplicate and improve dma address handling. - Prep work for supporting larger pages for zcrx. - Various little improvements and fixes. * tag 'for-6.17/io_uring-20250728' of git://git.kernel.dk/linux: (42 commits) io_uring/zcrx: fix leaking pages on sg init fail io_uring/zcrx: don't leak pages on account failure io_uring/zcrx: fix null ifq on area destruction io_uring: fix breakage in EXPERT menu io_uring/cmd: remove struct io_uring_cmd_data btrfs/ioctl: store btrfs_uring_encoded_data in io_btrfs_cmd io_uring/cmd: introduce IORING_URING_CMD_REISSUE flag io_uring/zcrx: account area memory io_uring: export io_[un]account_mem io_uring/net: Support multishot receive len cap io_uring: deduplicate wakeup handling io_uring/net: cast min_not_zero() type io_uring/poll: cleanup apoll freeing io_uring/net: allow multishot receive per-invocation cap io_uring/net: move io_sr_msg->retry_flags to io_sr_msg->flags io_uring/net: use passed in 'len' in io_recv_buf_select() io_uring/zcrx: prepare fallback for larger pages io_uring/zcrx: assert area type in io_zcrx_iov_page io_uring/zcrx: allocate sgtable for umem areas io_uring/zcrx: introduce io_populate_area_dma ...
2025-07-24pc104: move PC104 option to drivers/KconfigRandy Dunlap1-7/+0
Put the PC104 kconfig option in drivers/Kconfig along with other buses (AMBA, EISA, PCI, CXL, PCCard, & RapidIO). This localizes PC104 with option bus kconfig options to make it easier to find. Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Acked-by: William Breathitt Gray <wbg@kernel.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Link: https://lore.kernel.org/r/20250722235431.3671754-1-rdunlap@infradead.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-07-20io_uring: fix breakage in EXPERT menuRandy Dunlap1-1/+1
Add a dependency for IO_URING for the GCOV_PROFILE_URING symbol. Without this patch the EXPERT config menu ends with "Enable IO uring support" and the menu prompts for GCOV_PROFILE_URING and IO_URING_MOCK_FILE are not subordinate to it. This causes all of the EXPERT Kconfig options that follow GCOV_PROFILE_URING to be display in the "upper" menu (General setup), just following the EXPERT menu. Fixes: 1802656ef890 ("io_uring: add GCOV_PROFILE_URING Kconfig option") Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Cc: Jens Axboe <axboe@kernel.dk> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Masahiro Yamada <masahiroy@kernel.org> Cc: io-uring@vger.kernel.org Link: https://lore.kernel.org/r/20250720010456.2945344-1-rdunlap@infradead.org Signed-off-by: Jens Axboe <axboe@kernel.dk>
2025-07-19init/main.c: add warning when file specified in rdinit is inaccessibleLillian Berry1-1/+5
Avoid silently ignoring the initramfs when the file specified in rdinit is not usable. This prints an error that clearly explains the issue (file was not found, vs initramfs was not found). Link: https://lkml.kernel.org/r/20250707091411.1412681-1-lillian@star-ark.net Signed-off-by: Lillian Berry <lillian@star-ark.net> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-07-19mm/vmstat: make MEMCG select VM_EVENT_COUNTERSKirill A. Shutemov1-0/+1
The vmstat_text array contains labels for counters displayed in /proc/vmstat. It is important to keep the labels in sync with the counters. There is a BUILD_BUG_ON() check in vmstat_start() that ensures the size of the vmstat_text is not smaller than VM_EVENT_COUNTERS. This helps to catch cases where a new counter is added but the label is not. However, it does not help if a counter is removed but the label remains. It would be nice to make the BUILD_BUG_ON() check more strict to catch such cases. However, when compiling with MEMCG enabled but VM_EVENT_COUNTERS disabled, the vmstat_text array is larger than NR_VMSTAT_ITEMS. This issue arises because some elements of the vmstat_text array are present when either MEMCG or VM_EVENT_COUNTERS is enabled, but NR_VMSTAT_ITEMS only accounts for these elements if VM_EVENT_COUNTERS is enabled. Instead of adjusting the NR_VMSTAT_ITEMS definition to account for MEMCG, make MEMCG select VM_EVENT_COUNTERS. VM_EVENT_COUNTERS is enabled in most configurations anyway. Link: https://lkml.kernel.org/r/20250604095111.533783-1-kirill.shutemov@linux.intel.com Fixes: ebc5d83d0443 ("mm/memcontrol: use vmstat names for printing statistics") Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Reported-by: Randy Dunlap <rdunlap@infradead.org> Acked-by: Vlastimil Babka <vbabka@suse.cz> Tested-by: Randy Dunlap <rdunlap@infradead.org> Acked-by: Randy Dunlap <rdunlap@infradead.org> Acked-by: Shakeel Butt <shakeel.butt@linux.dev> Cc: Konstantin Khlebnikov <koct9i@gmail.com> Cc: David Hildenbrand <david@redhat.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Muchun Song <muchun.song@linux.dev> Cc: Suren Baghdasaryan <surenb@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-07-14sched: Add CONFIG_SCHED_PROXY_EXEC & boot argument to enable/disableJohn Stultz1-0/+12
Add a CONFIG_SCHED_PROXY_EXEC option, along with a boot argument sched_proxy_exec= that can be used to disable the feature at boot time if CONFIG_SCHED_PROXY_EXEC was enabled. Also uses this option to allow the rq->donor to be different from rq->curr. Signed-off-by: John Stultz <jstultz@google.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Tested-by: K Prateek Nayak <kprateek.nayak@amd.com> Link: https://lkml.kernel.org/r/20250712033407.2383110-2-jstultz@google.com
2025-07-14Merge branch 'tip/sched/urgent'Peter Zijlstra3-0/+6
Avoid merge conflicts Signed-off-by: Peter Zijlstra <peterz@infradead.org>
2025-07-11futex: Use RCU-based per-CPU reference counting instead of rcuref_tPeter Zijlstra1-4/+0
The use of rcuref_t for reference counting introduces a performance bottleneck when accessed concurrently by multiple threads during futex operations. Replace rcuref_t with special crafted per-CPU reference counters. The lifetime logic remains the same. The newly allocate private hash starts in FR_PERCPU state. In this state, each futex operation that requires the private hash uses a per-CPU counter (an unsigned int) for incrementing or decrementing the reference count. When the private hash is about to be replaced, the per-CPU counters are migrated to a atomic_t counter mm_struct::futex_atomic. The migration process: - Waiting for one RCU grace period to ensure all users observe the current private hash. This can be skipped if a grace period elapsed since the private hash was assigned. - futex_private_hash::state is set to FR_ATOMIC, forcing all users to use mm_struct::futex_atomic for reference counting. - After a RCU grace period, all users are guaranteed to be using the atomic counter. The per-CPU counters can now be summed up and added to the atomic_t counter. If the resulting count is zero, the hash can be safely replaced. Otherwise, active users still hold a valid reference. - Once the atomic reference count drops to zero, the next futex operation will switch to the new private hash. call_rcu_hurry() is used to speed up transition which otherwise might be delay with RCU_LAZY. There is nothing wrong with using call_rcu(). The side effects would be that on auto scaling the new hash is used later and the SET_SLOTS prctl() will block longer. [bigeasy: commit description + mm get/ put_async] Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lore.kernel.org/r/20250710110011.384614-3-bigeasy@linutronix.de
2025-07-02io_uring/mock: add basic infra for test mock filesPavel Begunkov1-0/+11
io_uring commands provide an ioctl style interface for files to implement file specific operations. io_uring provides many features and advanced api to commands, and it's getting hard to test as it requires specific files/devices. Add basic infrastucture for creating special mock files that will be implementing the cmd api and using various io_uring features we want to test. It'll also be useful to test some more obscure read/write/polling edge cases in the future. Suggested-by: chase xd <sl1589472800@gmail.com> Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/93f21b0af58c1367a2b22635d5a7d694ad0272fc.1750599274.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>