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2026-04-07rust: kbuild: remove "dummy parameter" workaround for `bindgen` < 0.71.1Miguel Ojeda
Until the version bump of `bindgen`, we needed to pass a dummy parameter to avoid failing the `--version` call. Thus remove it. Reviewed-by: Tamir Duberstein <tamird@kernel.org> Reviewed-by: Gary Guo <gary@garyguo.net> Link: https://patch.msgid.link/20260405235309.418950-22-ojeda@kernel.org Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2026-04-07rust: remove `RUSTC_HAS_COERCE_POINTEE` and simplify codeMiguel Ojeda
With the Rust version bump in place, the `RUSTC_HAS_COERCE_POINTEE` Kconfig (automatic) option is always true. Thus remove the option and simplify the code. In particular, this includes removing our use of the predecessor unstable features we used with Rust < 1.84.0 (`coerce_unsized`, `dispatch_from_dyn` and `unsize`). Reviewed-by: Tamir Duberstein <tamird@kernel.org> Acked-by: Danilo Krummrich <dakr@kernel.org> Reviewed-by: Gary Guo <gary@garyguo.net> Link: https://patch.msgid.link/20260405235309.418950-11-ojeda@kernel.org Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2026-04-07rust: remove `RUSTC_HAS_SLICE_AS_FLATTENED` and simplify codeMiguel Ojeda
With the Rust version bump in place, the `RUSTC_HAS_SLICE_AS_FLATTENED` Kconfig (automatic) option is always true. Thus remove the option and simplify the code. In particular, this includes removing the `slice` module which contained the temporary slice helpers, i.e. the `AsFlattened` extension trait and its `impl`s. Reviewed-by: Tamir Duberstein <tamird@kernel.org> Reviewed-by: Gary Guo <gary@garyguo.net> Link: https://patch.msgid.link/20260405235309.418950-10-ojeda@kernel.org Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2026-04-07rust: simplify `RUSTC_VERSION` Kconfig conditionsMiguel Ojeda
With the Rust version bump in place, several Kconfig conditions based on `RUSTC_VERSION` are always true. Thus simplify them. The minimum supported major LLVM version by our new Rust minimum version is now LLVM 18, instead of LLVM 16. However, there are no possible cleanups for `RUSTC_LLVM_VERSION`. Reviewed-by: Tamir Duberstein <tamird@kernel.org> Reviewed-by: Gary Guo <gary@garyguo.net> Link: https://patch.msgid.link/20260405235309.418950-9-ojeda@kernel.org Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2026-04-05mm: introduce CONFIG_NUMA_MIGRATION and simplify CONFIG_MIGRATIONDavid Hildenbrand (Arm)
CONFIG_MEMORY_HOTREMOVE, CONFIG_COMPACTION and CONFIG_CMA all select CONFIG_MIGRATION, because they require it to work (users). Only CONFIG_NUMA_BALANCING and CONFIG_BALLOON_MIGRATION depend on CONFIG_MIGRATION. CONFIG_BALLOON_MIGRATION is not an actual user, but an implementation of migration support, so the dependency is correct (CONFIG_BALLOON_MIGRATION does not make any sense without CONFIG_MIGRATION). However, kconfig-language.rst clearly states "In general use select only for non-visible symbols". So far CONFIG_MIGRATION is user-visible ... and the dependencies rather confusing. The whole reason why CONFIG_MIGRATION is user-visible is because of CONFIG_NUMA: some users might want CONFIG_NUMA but not page migration support. Let's clean all that up by introducing a dedicated CONFIG_NUMA_MIGRATION config option for that purpose only. Make CONFIG_NUMA_BALANCING that so far depended on CONFIG_NUMA && CONFIG_MIGRATION to depend on CONFIG_MIGRATION instead. CONFIG_NUMA_MIGRATION will depend on CONFIG_NUMA && CONFIG_MMU. CONFIG_NUMA_MIGRATION is user-visible and will default to "y". We use that default so new configs will automatically enable it, just like it was the case with CONFIG_MIGRATION. The downside is that some configs that used to have CONFIG_MIGRATION=n might get it re-enabled by CONFIG_NUMA_MIGRATION=y, which shouldn't be a problem. CONFIG_MIGRATION is now a non-visible config option. Any code that select CONFIG_MIGRATION (as before) must depend directly or indirectly on CONFIG_MMU. CONFIG_NUMA_MIGRATION is responsible for any NUMA migration code, which is mempolicy migration code, memory-tiering code, and move_pages() code in migrate.c. CONFIG_NUMA_BALANCING uses its functionality. Note that this implies that with CONFIG_NUMA_MIGRATION=n, move_pages() will not be available even though CONFIG_MIGRATION=y, which is an expected change. In migrate.c, we can remove the CONFIG_NUMA check as both CONFIG_NUMA_MIGRATION and CONFIG_NUMA_BALANCING depend on it. With this change, CONFIG_MIGRATION is an internal config, all users of migration selects CONFIG_MIGRATION, and only CONFIG_BALLOON_MIGRATION depends on it. Link: https://lkml.kernel.org/r/20260319-config_migration-v1-2-42270124966f@kernel.org Signed-off-by: David Hildenbrand (Arm) <david@kernel.org> Reviewed-by: Lorenzo Stoakes (Oracle) <ljs@kernel.org> Acked-by: Zi Yan <ziy@nvidia.com> Reviewed-by: Jonathan Cameron <jonathan.cameron@huawei.com> Cc: Albert Ou <aou@eecs.berkeley.edu> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Alexandre Ghiti <alex@ghiti.fr> Cc: Alistair Popple <apopple@nvidia.com> Cc: "Borislav Petkov (AMD)" <bp@alien8.de> Cc: Byungchul Park <byungchul@sk.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Christian Borntraeger <borntraeger@linux.ibm.com> Cc: Gregory Price <gourry@gourry.net> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Huacai Chen <chenhuacai@kernel.org> Cc: "Huang, Ying" <ying.huang@linux.alibaba.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Joshua Hahn <joshua.hahnjy@gmail.com> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Madhavan Srinivasan <maddy@linux.ibm.com> Cc: Matthew Brost <matthew.brost@intel.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Rakie Kim <rakie.kim@sk.com> Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Sven Schnelle <svens@linux.ibm.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: WANG Xuerui <kernel@xen0n.name> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-04-03kernel: ksysfs: initialize kernel_kobj earlierBartosz Golaszewski
Software nodes depend on kernel_kobj which is initialized pretty late into the boot process - as a core_initcall(). Ahead of moving the software node initialization to driver_init() we must first make kernel_kobj available before it. Make ksysfs_init() visible in a new header - ksysfs.h - and call it in do_basic_setup() right before driver_init(). Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@oss.qualcomm.com> Link: https://patch.msgid.link/20260402-nokia770-gpio-swnodes-v5-1-d730db3dd299@oss.qualcomm.com Signed-off-by: Danilo Krummrich <dakr@kernel.org>
2026-04-03locking: Add task::blocked_lock to serialize blocked_on stateJohn Stultz
So far, we have been able to utilize the mutex::wait_lock for serializing the blocked_on state, but when we move to proxying across runqueues, we will need to add more state and a way to serialize changes to this state in contexts where we don't hold the mutex::wait_lock. So introduce the task::blocked_lock, which nests under the mutex::wait_lock in the locking order, and rework the locking to use it. Signed-off-by: John Stultz <jstultz@google.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: K Prateek Nayak <kprateek.nayak@amd.com> Link: https://patch.msgid.link/20260324191337.1841376-5-jstultz@google.com
2026-04-01memblock: make free_reserved_area() update memblock if ARCH_KEEP_MEMBLOCK=yMike Rapoport (Microsoft)
On architectures that keep memblock after boot, freeing of reserved memory with free_reserved_area() is paired with an update of memblock arrays, usually by a call to memblock_free(). Make free_reserved_area() directly update memblock.reserved when ARCH_KEEP_MEMBLOCK is enabled. Remove the now-redundant explicit memblock_free() call from arm64::free_initmem() and the #ifdef CONFIG_ARCH_KEEP_MEMBLOCK block from the generic free_initrd_mem(). Link: https://patch.msgid.link/20260323074836.3653702-8-rppt@kernel.org Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
2026-03-30kbuild: rust: add `CONFIG_RUSTC_CLANG_LLVM_COMPATIBLE`Gary Guo
This config detects if Rust and Clang have matching LLVM major version. All IR or bitcode operations (e.g. LTO) rely on LLVM major version to be matching, otherwise it may generate errors, or worse, miscompile silently due to change of IR semantics. It's usually suggested to use the exact same LLVM version, but this can be difficult to guarantee. Rust's suggestion [1] is also major-version only, so I think this check is sufficient for the kernel. Link: https://doc.rust-lang.org/rustc/linker-plugin-lto.html [1] Reviewed-by: Andreas Hindborg <a.hindborg@kernel.org> Signed-off-by: Gary Guo <gary@garyguo.net> Signed-off-by: Matthew Maurer <mmaurer@google.com> Signed-off-by: Alice Ryhl <aliceryhl@google.com> Reviewed-by: Nathan Chancellor <nathan@kernel.org> Tested-by: Nathan Chancellor <nathan@kernel.org> Reviewed-by: Nicolas Schier <nsc@kernel.org> Tested-by: Nicolas Schier <nsc@kernel.org> Tested-by: Andreas Hindborg <a.hindborg@kernel.org> Link: https://patch.msgid.link/20260203-inline-helpers-v2-1-beb8547a03c9@google.com [ Fixed typo. - Miguel ] Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2026-03-26timens: Remove dependency on the vDSOThomas Weißschuh
Previously, missing time namespace support in the vDSO meant that time namespaces needed to be disabled globally. This was expressed in a hard dependency on the generic vDSO library. This also meant that architectures without any vDSO or only a stub vDSO could not enable time namespaces. Now that all architectures using a real vDSO are using the generic library, that dependency is not necessary anymore. Remove the dependency and let all architectures enable time namespaces. Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de> Signed-off-by: Thomas Gleixner <tglx@kernel.org> Link: https://patch.msgid.link/20260326-vdso-timens-decoupling-v2-2-c82693a7775f@linutronix.de
2026-03-25Merge tag 'hardening-v7.0-rc6' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux Pull hardening fixes from Kees Cook: - fix required Clang version for CC_HAS_COUNTED_BY_PTR (Nathan Chancellor) - update Coccinelle script used for kmalloc_obj * tag 'hardening-v7.0-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux: init/Kconfig: Require a release version of clang-22 for CC_HAS_COUNTED_BY_PTR coccinelle: kmalloc_obj: Remove default GFP_KERNEL arg
2026-03-24randomize_kstack: Unify random source across archesRyan Roberts
Previously different architectures were using random sources of differing strength and cost to decide the random kstack offset. A number of architectures (loongarch, powerpc, s390, x86) were using their timestamp counter, at whatever the frequency happened to be. Other arches (arm64, riscv) were using entropy from the crng via get_random_u16(). There have been concerns that in some cases the timestamp counters may be too weak, because they can be easily guessed or influenced by user space. And get_random_u16() has been shown to be too costly for the level of protection kstack offset randomization provides. So let's use a common, architecture-agnostic source of entropy; a per-cpu prng, seeded at boot-time from the crng. This has a few benefits: - We can remove choose_random_kstack_offset(); That was only there to try to make the timestamp counter value a bit harder to influence from user space [*]. - The architecture code is simplified. All it has to do now is call add_random_kstack_offset() in the syscall path. - The strength of the randomness can be reasoned about independently of the architecture. - Arches previously using get_random_u16() now have much faster syscall paths, see below results. [*] Additionally, this gets rid of some redundant work on s390 and x86. Before this patch, those architectures called choose_random_kstack_offset() under arch_exit_to_user_mode_prepare(), which is also called for exception returns to userspace which were *not* syscalls (e.g. regular interrupts). Getting rid of choose_random_kstack_offset() avoids a small amount of redundant work for the non-syscall cases. In some configurations, add_random_kstack_offset() will now call instrumentable code, so for a couple of arches, I have moved the call a bit later to the first point where instrumentation is allowed. This doesn't impact the efficacy of the mechanism. There have been some claims that a prng may be less strong than the timestamp counter if not regularly reseeded. But the prng has a period of about 2^113. So as long as the prng state remains secret, it should not be possible to guess. If the prng state can be accessed, we have bigger problems. Additionally, we are only consuming 6 bits to randomize the stack, so there are only 64 possible random offsets. I assert that it would be trivial for an attacker to brute force by repeating their attack and waiting for the random stack offset to be the desired one. The prng approach seems entirely proportional to this level of protection. Performance data are provided below. The baseline is v6.18 with rndstack on for each respective arch. (I)/(R) indicate statistically significant improvement/regression. arm64 platform is AWS Graviton3 (m7g.metal). x86_64 platform is AWS Sapphire Rapids (m7i.24xlarge): +-----------------+--------------+---------------+---------------+ | Benchmark | Result Class | per-cpu-prng | per-cpu-prng | | | | arm64 (metal) | x86_64 (VM) | +=================+==============+===============+===============+ | syscall/getpid | mean (ns) | (I) -9.50% | (I) -17.65% | | | p99 (ns) | (I) -59.24% | (I) -24.41% | | | p99.9 (ns) | (I) -59.52% | (I) -28.52% | +-----------------+--------------+---------------+---------------+ | syscall/getppid | mean (ns) | (I) -9.52% | (I) -19.24% | | | p99 (ns) | (I) -59.25% | (I) -25.03% | | | p99.9 (ns) | (I) -59.50% | (I) -28.17% | +-----------------+--------------+---------------+---------------+ | syscall/invalid | mean (ns) | (I) -10.31% | (I) -18.56% | | | p99 (ns) | (I) -60.79% | (I) -20.06% | | | p99.9 (ns) | (I) -61.04% | (I) -25.04% | +-----------------+--------------+---------------+---------------+ I tested an earlier version of this change on x86 bare metal and it showed a smaller but still significant improvement. The bare metal system wasn't available this time around so testing was done in a VM instance. I'm guessing the cost of rdtsc is higher for VMs. Acked-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Ryan Roberts <ryan.roberts@arm.com> Link: https://patch.msgid.link/20260303150840.3789438-3-ryan.roberts@arm.com Signed-off-by: Kees Cook <kees@kernel.org>
2026-03-24randomize_kstack: Maintain kstack_offset per taskRyan Roberts
kstack_offset was previously maintained per-cpu, but this caused a couple of issues. So let's instead make it per-task. Issue 1: add_random_kstack_offset() and choose_random_kstack_offset() expected and required to be called with interrupts and preemption disabled so that it could manipulate per-cpu state. But arm64, loongarch and risc-v are calling them with interrupts and preemption enabled. I don't _think_ this causes any functional issues, but it's certainly unexpected and could lead to manipulating the wrong cpu's state, which could cause a minor performance degradation due to bouncing the cache lines. By maintaining the state per-task those functions can safely be called in preemptible context. Issue 2: add_random_kstack_offset() is called before executing the syscall and expands the stack using a previously chosen random offset. choose_random_kstack_offset() is called after executing the syscall and chooses and stores a new random offset for the next syscall. With per-cpu storage for this offset, an attacker could force cpu migration during the execution of the syscall and prevent the offset from being updated for the original cpu such that it is predictable for the next syscall on that cpu. By maintaining the state per-task, this problem goes away because the per-task random offset is updated after the syscall regardless of which cpu it is executing on. Fixes: 39218ff4c625 ("stack: Optionally randomize kernel stack offset each syscall") Closes: https://lore.kernel.org/all/dd8c37bc-795f-4c7a-9086-69e584d8ab24@arm.com/ Cc: stable@vger.kernel.org Acked-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Ryan Roberts <ryan.roberts@arm.com> Link: https://patch.msgid.link/20260303150840.3789438-2-ryan.roberts@arm.com Signed-off-by: Kees Cook <kees@kernel.org>
2026-03-22sched_ext: Fix build errors and unused label warning in non-cgroup configsCheng-Yang Chou
When building with SCHED_CLASS_EXT=y but CGROUPS=n, clang reports errors for undeclared cgroup_put() and cgroup_get() calls, and a warning for the unused err_stop_helper label. EXT_SUB_SCHED is def_bool y depending only on SCHED_CLASS_EXT, but it fundamentally requires cgroups (cgroup_path, cgroup_get, cgroup_put, cgroup_id, etc.). Add the missing CGROUPS dependency to EXT_SUB_SCHED in init/Kconfig. Guard cgroup_put() and cgroup_get() in the common paths with: #if defined(CONFIG_EXT_GROUP_SCHED) || defined(CONFIG_EXT_SUB_SCHED) Guard the err_stop_helper label with #ifdef CONFIG_EXT_SUB_SCHED since all gotos targeting it are inside that same ifdef block. Tested with both CGROUPS enabled and disabled. Fixes: ebeca1f930ea ("sched_ext: Introduce cgroup sub-sched support") Reported-by: kernel test robot <lkp@intel.com> Closes: https://lore.kernel.org/oe-kbuild-all/202603210903.IrKhPd6k-lkp@intel.com/ Signed-off-by: Cheng-Yang Chou <yphbchou0911@gmail.com> Acked-by: Andrea Righi <arighi@nvidia.com> Signed-off-by: Tejun Heo <tj@kernel.org>
2026-03-20init/Kconfig: Require a release version of clang-22 for CC_HAS_COUNTED_BY_PTRNathan Chancellor
Commit 150a04d817d8 ("compiler_types.h: Attributes: Add __counted_by_ptr macro") used Clang 22.0.0 as a minimum supported version for __counted_by_ptr, which made sense while 22.0.0 was the version of LLVM's main branch to allow developers to easily test and develop uses of __counted_by_ptr in their code. However, __counted_by_ptr requires a change [1] merged towards the end of the 22 development cycle to avoid errors when applied to void pointers. In file included from fs/xfs/xfs_attr_inactive.c:18: fs/xfs/libxfs/xfs_attr.h:59:2: error: 'counted_by' cannot be applied to a pointer with pointee of unknown size because 'void' is an incomplete type 59 | void *buffer __counted_by_ptr(bufsize); | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ This is disruptive for deployed prerelease clang-22 builds (such as Android LLVM) or when bisecting between llvmorg-21-init and the fix. Require a released version of clang-22 (i.e., 21.1.0 or newer) to enabled __counted_by_ptr to ensure all fixes needed for proper support are present. Fixes: 150a04d817d8 ("compiler_types.h: Attributes: Add __counted_by_ptr macro") Link: https://github.com/llvm/llvm-project/commit/f29955a594aedf5943d492a999b83e8c6b8fafae [1] Signed-off-by: Nathan Chancellor <nathan@kernel.org> Link: https://patch.msgid.link/20260318-counted_by_ptr-release-clang-22-v1-1-e017da246df0@kernel.org Signed-off-by: Kees Cook <kees@kernel.org>
2026-03-20init/initramfs.c: trivial fix: FSM -> Finite-state machineAskar Safin
FSM means "finite-state machine", but I think this is not obvious to everyone. Signed-off-by: Askar Safin <safinaskar@gmail.com> Link: https://patch.msgid.link/20260319232721.452950-1-safinaskar@gmail.com Signed-off-by: Christian Brauner <brauner@kernel.org>
2026-03-12kbuild: Use '-fms-anonymous-structs' if it is availableNathan Chancellor
Clang recently added '-fms-anonymous-structs' [1] to specifically enable the Microsoft tagged anonymous structure / union extension, for which the kernel added '-fms-extensions' in commit c4781dc3d1cf ("Kbuild: enable -fms-extensions"). Switch to this more narrow option if it is available, which would have helped avoid the issue addressed by commit a6773e6932cb ("jfs: Rename _inline to avoid conflict with clang's '-fms-extensions'"). GCC has talked about adding a similar flag [2] as well but potentially naming it differently. Move the selection of the flag to Kconfig to make it easier to use cc-option (as CC_FLAGS_DIALECT may be used in arch Makefiles, which may be too early for cc-option in Kbuild) and customize based on compiler flag names. Link: https://github.com/llvm/llvm-project/commit/c391efe6fb67329d8e2fd231692cc6b0ea902956 [1] Link: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=123623 [2] Signed-off-by: Nathan Chancellor <nathan@kernel.org> Reviewed-by: Nicolas Schier <nsc@kernel.org> Reviewed-by: Kees Cook <kees@kernel.org> Acked-by: Ard Biesheuvel <ardb@kernel.org> Acked-by: Helge Deller <deller@gmx.de> # parisc Link: https://patch.msgid.link/20260223-fms-anonymous-structs-v1-2-8ee406d3c36c@kernel.org Signed-off-by: Nicolas Schier <nsc@kernel.org>
2026-03-11vdso/datastore: Allocate data pages dynamicallyThomas Weißschuh
Allocating the data pages as part of the kernel image does not work on SPARC. The MMU will raise a fault when userspace tries to access them. Allocate the data pages through the page allocator instead. Unused pages in the vDSO VMA are still allocated to keep the virtual addresses aligned. Switch the mapping from PFNs to 'struct page' as that is required for dynamically allocated pages. This also aligns the allocation of the datapages with the code pages and is a prerequisite for mlockall() support. VM_MIXEDMAP is necessary for the call to vmf_insert_page() in the timens prefault path to work. The data pages need to be order-0, non-compound pages so that the mapping to userspace and the different orderings work. These pages are also used by the timekeeping, random pool and architecture initialization code. Some of these are running before the page allocator is available. To keep these subsytems working without changes, introduce early, statically data storage which will then replaced by the real one as soon as that is available. Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de> Signed-off-by: Thomas Gleixner <tglx@kernel.org> Reviewed-by: Christophe Leroy (CS GROUP) <chleroy@kernel.org> Link: https://patch.msgid.link/20260304-vdso-sparc64-generic-2-v6-3-d8eb3b0e1410@linutronix.de
2026-03-06sched_ext: Introduce cgroup sub-sched supportTejun Heo
A system often runs multiple workloads especially in multi-tenant server environments where a system is split into partitions servicing separate more-or-less independent workloads each requiring an application-specific scheduler. To support such and other use cases, sched_ext is in the process of growing multiple scheduler support. When partitioning a system in terms of CPUs for such use cases, an oft-taken approach is hard partitioning the system using cpuset. While it would be possible to tie sched_ext multiple scheduler support to cpuset partitions, such an approach would have fundamental limitations stemming from the lack of dynamism and flexibility. Users often don't care which specific CPUs are assigned to which workload and want to take advantage of optimizations which are enabled by running workloads on a larger machine - e.g. opportunistic over-commit, improving latency critical workload characteristics while maintaining bandwidth fairness, employing control mechanisms based on different criteria than on-CPU time for e.g. flexible memory bandwidth isolation, packing similar parts from different workloads on same L3s to improve cache efficiency, and so on. As this sort of dynamic behaviors are impossible or difficult to implement with hard partitioning, sched_ext is implementing cgroup sub-sched support where schedulers can be attached to the cgroup hierarchy and a parent scheduler is responsible for controlling the CPUs that each child can use at any given moment. This makes CPU distribution dynamically controlled by BPF allowing high flexibility. This patch adds the skeletal sched_ext cgroup sub-sched support: - sched_ext_ops.sub_cgroup_id and .sub_attach/detach() are added. Non-zero sub_cgroup_id indicates that the scheduler is to be attached to the identified cgroup. A sub-sched is attached to the cgroup iff the nearest ancestor scheduler implements .sub_attach() and grants the attachment. Max nesting depth is limited by SCX_SUB_MAX_DEPTH. - When a scheduler exits, all its descendant schedulers are exited together. Also, cgroup.scx_sched added which points to the effective scheduler instance for the cgroup. This is updated on scheduler init/exit and inherited on cgroup online. When a cgroup is offlined, the attached scheduler is automatically exited. - Sub-sched support is gated on CONFIG_EXT_SUB_SCHED which is automatically enabled if both SCX and cgroups are enabled. Sub-sched support is not tied to the CPU controller but rather the cgroup hierarchy itself. This is intentional as the support for cpu.weight and cpu.max based resource control is orthogonal to sub-sched support. Note that CONFIG_CGROUPS around cgroup subtree iteration support for scx_task_iter is replaced with CONFIG_EXT_SUB_SCHED for consistency. - This allows loading sub-scheds and most framework operations such as propagating disable down the hierarchy work. However, sub-scheds are not operational yet and all tasks stay with the root sched. This will serve as the basis for building up full sub-sched support. - DSQs point to the scx_sched they belong to. - scx_qmap is updated to allow attachment of sub-scheds and also serving as sub-scheds. - scx_is_descendant() is added but not yet used in this patch. It is used by later changes in the series and placed here as this is where the function belongs. Signed-off-by: Tejun Heo <tj@kernel.org> Reviewed-by: Andrea Righi <arighi@nvidia.com>
2026-03-06Merge tag 'io_uring-7.0-20260305' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux Pull io_uring fixes from Jens Axboe: - Fix a typo in the mock_file help text - Fix a comment regarding IORING_SETUP_TASKRUN_FLAG in the io_uring.h UAPI header - Use READ_ONCE() for reading refill queue entries - Reject SEND_VECTORIZED for fixed buffer sends, as it isn't implemented. Currently this flag is silently ignored This is in preparation for making these work, but first we need a fixup so that older kernels will correctly reject them - Ensure "0" means default for the rx page size * tag 'io_uring-7.0-20260305' of git://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux: io_uring/zcrx: use READ_ONCE with user shared RQEs io_uring/mock: Fix typo in help text io_uring/net: reject SEND_VECTORIZED when unsupported io_uring: correct comment for IORING_SETUP_TASKRUN_FLAG io_uring/zcrx: don't set rx_page_size when not requested
2026-03-03io_uring/mock: Fix typo in help textJ. Neuschäfer
Fix the spelling of "subsystem". Signed-off-by: J. Neuschäfer <j.ne@posteo.net> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-02-23init/Kconfig: Adjust fixed clang version for __builtin_counted_by_refNathan Chancellor
Commit d39a1d7486d9 ("compiler_types: Disable __builtin_counted_by_ref for Clang") used 22.0.0 as the fixed version for a compiler crash but the fix was only merged in main (23.0.0) and release/22.x (22.1.0). With the current fixed version number, prerelease or Android LLVM 22 builds will still be able to hit the compiler crash when building the kernel. This can be particularly disruptive when bisecting LLVM. Use 21.1.0 as the fixed version number to ensure the fix for this crash is always present. Fixes: d39a1d7486d9 ("compiler_types: Disable __builtin_counted_by_ref for Clang") Signed-off-by: Nathan Chancellor <nathan@kernel.org> Link: https://patch.msgid.link/20260223-fix-clang-version-builtin-counted-by-ref-v1-1-3ea478a24f0a@kernel.org Signed-off-by: Kees Cook <kees@kernel.org>
2026-02-21Convert 'alloc_flex' family to use the new default GFP_KERNEL argumentLinus Torvalds
This is the exact same thing as the 'alloc_obj()' version, only much smaller because there are a lot fewer users of the *alloc_flex() interface. As with alloc_obj() version, this was done entirely with mindless brute force, using the same script, except using 'flex' in the pattern rather than 'objs*'. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2026-02-21Convert 'alloc_obj' family to use the new default GFP_KERNEL argumentLinus Torvalds
This was done entirely with mindless brute force, using git grep -l '\<k[vmz]*alloc_objs*(.*, GFP_KERNEL)' | xargs sed -i 's/\(alloc_objs*(.*\), GFP_KERNEL)/\1)/' to convert the new alloc_obj() users that had a simple GFP_KERNEL argument to just drop that argument. Note that due to the extreme simplicity of the scripting, any slightly more complex cases spread over multiple lines would not be triggered: they definitely exist, but this covers the vast bulk of the cases, and the resulting diff is also then easier to check automatically. For the same reason the 'flex' versions will be done as a separate conversion. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2026-02-21treewide: Replace kmalloc with kmalloc_obj for non-scalar typesKees Cook
This is the result of running the Coccinelle script from scripts/coccinelle/api/kmalloc_objs.cocci. The script is designed to avoid scalar types (which need careful case-by-case checking), and instead replace kmalloc-family calls that allocate struct or union object instances: Single allocations: kmalloc(sizeof(TYPE), ...) are replaced with: kmalloc_obj(TYPE, ...) Array allocations: kmalloc_array(COUNT, sizeof(TYPE), ...) are replaced with: kmalloc_objs(TYPE, COUNT, ...) Flex array allocations: kmalloc(struct_size(PTR, FAM, COUNT), ...) are replaced with: kmalloc_flex(*PTR, FAM, COUNT, ...) (where TYPE may also be *VAR) The resulting allocations no longer return "void *", instead returning "TYPE *". Signed-off-by: Kees Cook <kees@kernel.org>
2026-02-21compiler_types: Disable __builtin_counted_by_ref for ClangKees Cook
Unfortunately, there is a corner case of __builtin_counted_by_ref() usage that crashes[1] Clang since support was introduced in Clang 19. Disable it prior to Clang 22. Found while tested kmalloc_obj treewide refactoring (via kmalloc_flex() usage). Link: https://github.com/llvm/llvm-project/issues/182575 [1] Signed-off-by: Kees Cook <kees@kernel.org>
2026-02-12Merge tag 'mm-nonmm-stable-2026-02-12-10-48' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Pull non-MM updates from Andrew Morton: - "ocfs2: give ocfs2 the ability to reclaim suballocator free bg" saves disk space by teaching ocfs2 to reclaim suballocator block group space (Heming Zhao) - "Add ARRAY_END(), and use it to fix off-by-one bugs" adds the ARRAY_END() macro and uses it in various places (Alejandro Colomar) - "vmcoreinfo: support VMCOREINFO_BYTES larger than PAGE_SIZE" makes the vmcore code future-safe, if VMCOREINFO_BYTES ever exceeds the page size (Pnina Feder) - "kallsyms: Prevent invalid access when showing module buildid" cleans up kallsyms code related to module buildid and fixes an invalid access crash when printing backtraces (Petr Mladek) - "Address page fault in ima_restore_measurement_list()" fixes a kexec-related crash that can occur when booting the second-stage kernel on x86 (Harshit Mogalapalli) - "kho: ABI headers and Documentation updates" updates the kexec handover ABI documentation (Mike Rapoport) - "Align atomic storage" adds the __aligned attribute to atomic_t and atomic64_t definitions to get natural alignment of both types on csky, m68k, microblaze, nios2, openrisc and sh (Finn Thain) - "kho: clean up page initialization logic" simplifies the page initialization logic in kho_restore_page() (Pratyush Yadav) - "Unload linux/kernel.h" moves several things out of kernel.h and into more appropriate places (Yury Norov) - "don't abuse task_struct.group_leader" removes the usage of ->group_leader when it is "obviously unnecessary" (Oleg Nesterov) - "list private v2 & luo flb" adds some infrastructure improvements to the live update orchestrator (Pasha Tatashin) * tag 'mm-nonmm-stable-2026-02-12-10-48' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (107 commits) watchdog/hardlockup: simplify perf event probe and remove per-cpu dependency procfs: fix missing RCU protection when reading real_parent in do_task_stat() watchdog/softlockup: fix sample ring index wrap in need_counting_irqs() kcsan, compiler_types: avoid duplicate type issues in BPF Type Format kho: fix doc for kho_restore_pages() tests/liveupdate: add in-kernel liveupdate test liveupdate: luo_flb: introduce File-Lifecycle-Bound global state liveupdate: luo_file: Use private list list: add kunit test for private list primitives list: add primitives for private list manipulations delayacct: fix uapi timespec64 definition panic: add panic_force_cpu= parameter to redirect panic to a specific CPU netclassid: use thread_group_leader(p) in update_classid_task() RDMA/umem: don't abuse current->group_leader drm/pan*: don't abuse current->group_leader drm/amd: kill the outdated "Only the pthreads threading model is supported" checks drm/amdgpu: don't abuse current->group_leader android/binder: use same_thread_group(proc->tsk, current) in binder_mmap() android/binder: don't abuse current->group_leader kho: skip memoryless NUMA nodes when reserving scratch areas ...
2026-02-12Merge tag 'mm-stable-2026-02-11-19-22' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Pull MM updates from Andrew Morton: - "powerpc/64s: do not re-activate batched TLB flush" makes arch_{enter|leave}_lazy_mmu_mode() nest properly (Alexander Gordeev) It adds a generic enter/leave layer and switches architectures to use it. Various hacks were removed in the process. - "zram: introduce compressed data writeback" implements data compression for zram writeback (Richard Chang and Sergey Senozhatsky) - "mm: folio_zero_user: clear page ranges" adds clearing of contiguous page ranges for hugepages. Large improvements during demand faulting are demonstrated (David Hildenbrand) - "memcg cleanups" tidies up some memcg code (Chen Ridong) - "mm/damon: introduce {,max_}nr_snapshots and tracepoint for damos stats" improves DAMOS stat's provided information, deterministic control, and readability (SeongJae Park) - "selftests/mm: hugetlb cgroup charging: robustness fixes" fixes a few issues in the hugetlb cgroup charging selftests (Li Wang) - "Fix va_high_addr_switch.sh test failure - again" addresses several issues in the va_high_addr_switch test (Chunyu Hu) - "mm/damon/tests/core-kunit: extend existing test scenarios" improves the KUnit test coverage for DAMON (Shu Anzai) - "mm/khugepaged: fix dirty page handling for MADV_COLLAPSE" fixes a glitch in khugepaged which was causing madvise(MADV_COLLAPSE) to transiently return -EAGAIN (Shivank Garg) - "arch, mm: consolidate hugetlb early reservation" reworks and consolidates a pile of straggly code related to reservation of hugetlb memory from bootmem and creation of CMA areas for hugetlb (Mike Rapoport) - "mm: clean up anon_vma implementation" cleans up the anon_vma implementation in various ways (Lorenzo Stoakes) - "tweaks for __alloc_pages_slowpath()" does a little streamlining of the page allocator's slowpath code (Vlastimil Babka) - "memcg: separate private and public ID namespaces" cleans up the memcg ID code and prevents the internal-only private IDs from being exposed to userspace (Shakeel Butt) - "mm: hugetlb: allocate frozen gigantic folio" cleans up the allocation of frozen folios and avoids some atomic refcount operations (Kefeng Wang) - "mm/damon: advance DAMOS-based LRU sorting" improves DAMOS's movement of memory betewwn the active and inactive LRUs and adds auto-tuning of the ratio-based quotas and of monitoring intervals (SeongJae Park) - "Support page table check on PowerPC" makes CONFIG_PAGE_TABLE_CHECK_ENFORCED work on powerpc (Andrew Donnellan) - "nodemask: align nodes_and{,not} with underlying bitmap ops" makes nodes_and() and nodes_andnot() propagate the return values from the underlying bit operations, enabling some cleanup in calling code (Yury Norov) - "mm/damon: hide kdamond and kdamond_lock from API callers" cleans up some DAMON internal interfaces (SeongJae Park) - "mm/khugepaged: cleanups and scan limit fix" does some cleanup work in khupaged and fixes a scan limit accounting issue (Shivank Garg) - "mm: balloon infrastructure cleanups" goes to town on the balloon infrastructure and its page migration function. Mainly cleanups, also some locking simplification (David Hildenbrand) - "mm/vmscan: add tracepoint and reason for kswapd_failures reset" adds additional tracepoints to the page reclaim code (Jiayuan Chen) - "Replace wq users and add WQ_PERCPU to alloc_workqueue() users" is part of Marco's kernel-wide migration from the legacy workqueue APIs over to the preferred unbound workqueues (Marco Crivellari) - "Various mm kselftests improvements/fixes" provides various unrelated improvements/fixes for the mm kselftests (Kevin Brodsky) - "mm: accelerate gigantic folio allocation" greatly speeds up gigantic folio allocation, mainly by avoiding unnecessary work in pfn_range_valid_contig() (Kefeng Wang) - "selftests/damon: improve leak detection and wss estimation reliability" improves the reliability of two of the DAMON selftests (SeongJae Park) - "mm/damon: cleanup kdamond, damon_call(), damos filter and DAMON_MIN_REGION" does some cleanup work in the core DAMON code (SeongJae Park) - "Docs/mm/damon: update intro, modules, maintainer profile, and misc" performs maintenance work on the DAMON documentation (SeongJae Park) - "mm: add and use vma_assert_stabilised() helper" refactors and cleans up the core VMA code. The main aim here is to be able to use the mmap write lock's lockdep state to perform various assertions regarding the locking which the VMA code requires (Lorenzo Stoakes) - "mm, swap: swap table phase II: unify swapin use" removes some old swap code (swap cache bypassing and swap synchronization) which wasn't working very well. Various other cleanups and simplifications were made. The end result is a 20% speedup in one benchmark (Kairui Song) - "enable PT_RECLAIM on more 64-bit architectures" makes PT_RECLAIM available on 64-bit alpha, loongarch, mips, parisc, and um. Various cleanups were performed along the way (Qi Zheng) * tag 'mm-stable-2026-02-11-19-22' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (325 commits) mm/memory: handle non-split locks correctly in zap_empty_pte_table() mm: move pte table reclaim code to memory.c mm: make PT_RECLAIM depends on MMU_GATHER_RCU_TABLE_FREE mm: convert __HAVE_ARCH_TLB_REMOVE_TABLE to CONFIG_HAVE_ARCH_TLB_REMOVE_TABLE config um: mm: enable MMU_GATHER_RCU_TABLE_FREE parisc: mm: enable MMU_GATHER_RCU_TABLE_FREE mips: mm: enable MMU_GATHER_RCU_TABLE_FREE LoongArch: mm: enable MMU_GATHER_RCU_TABLE_FREE alpha: mm: enable MMU_GATHER_RCU_TABLE_FREE mm: change mm/pt_reclaim.c to use asm/tlb.h instead of asm-generic/tlb.h mm/damon/stat: remove __read_mostly from memory_idle_ms_percentiles zsmalloc: make common caches global mm: add SPDX id lines to some mm source files mm/zswap: use %pe to print error pointers mm/vmscan: use %pe to print error pointers mm/readahead: fix typo in comment mm: khugepaged: fix NR_FILE_PAGES and NR_SHMEM in collapse_file() mm: refactor vma_map_pages to use vm_insert_pages mm/damon: unify address range representation with damon_addr_range mm/cma: replace snprintf with strscpy in cma_new_area ...
2026-02-11Merge tag 'kbuild-7.0-1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/kbuild/linux Pull Kbuild/Kconfig updates from Nathan Chancellor: "Kbuild: - Drop '*_probe' pattern from modpost section check allowlist, which hid legitimate warnings (Johan Hovold) - Disable -Wtype-limits altogether, instead of enabling at W=2 (Vincent Mailhol) - Improve UAPI testing to skip testing headers that require a libc when CONFIG_CC_CAN_LINK is not set, opening up testing of headers with no libc dependencies to more environments (Thomas Weißschuh) - Update gendwarfksyms documentation with required dependencies (Jihan LIN) - Reject invalid LLVM= values to avoid unintentionally falling back to system toolchain (Thomas Weißschuh) - Add a script to help run the kernel build process in a container for consistent environments and testing (Guillaume Tucker) - Simplify kallsyms by getting rid of the relative base (Ard Biesheuvel) - Performance and usability improvements to scripts/make_fit.py (Simon Glass) - Minor various clean ups and fixes Kconfig: - Move XPM icons to individual files, clearing up GTK deprecation warnings (Rostislav Krasny) - Support depends on FOO if BAR as syntactic sugar for depends on FOO || !BAR (Nicolas Pitre, Graham Roff) - Refactor merge_config.sh to use awk over shell/sed/grep, dramatically speeding up processing large number of config fragments (Anders Roxell, Mikko Rapeli)" * tag 'kbuild-7.0-1' of git://git.kernel.org/pub/scm/linux/kernel/git/kbuild/linux: (39 commits) kbuild: remove dependency of run-command on config scripts/make_fit: Compress dtbs in parallel scripts/make_fit: Support a few more parallel compressors kbuild: Support a FIT_EXTRA_ARGS environment variable scripts/make_fit: Move dtb processing into a function scripts/make_fit: Support an initial ramdisk scripts/make_fit: Speed up operation rust: kconfig: Don't require RUST_IS_AVAILABLE for rustc-option MAINTAINERS: Add scripts/install.sh into Kbuild entry modpost: Amend ppc64 save/restfpr symnames for -Os build MIPS: tools: relocs: Ship a definition of R_MIPS_PC32 streamline_config.pl: remove superfluous exclamation mark kbuild: dummy-tools: Add python3 scripts: kconfig: merge_config.sh: warn on duplicate input files scripts: kconfig: merge_config.sh: use awk in checks too scripts: kconfig: merge_config.sh: refactor from shell/sed/grep to awk kallsyms: Get rid of kallsyms relative base mips: Add support for PC32 relocations in vmlinux Documentation: dev-tools: add container.rst page scripts: add tool to run containerized builds ...
2026-02-10Merge tag 'sched-core-2026-02-09' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull scheduler updates from Ingo Molnar: "Scheduler Kconfig space updates: - Further consolidate configurable preemption modes (Peter Zijlstra) Reduce the number of architectures that are allowed to offer PREEMPT_NONE and PREEMPT_VOLUNTARY, reducing the number of preemption models from four to just two: 'full' and 'lazy' on up-to-date architectures (arm64, loongarch, powerpc, riscv, s390, x86). None and voluntary are only available as legacy features on platforms that don't implement lazy preemption yet, or which don't even support preemption. The goal is to eventually remove cond_resched() and voluntary preemption altogether. RSEQ based 'scheduler time slice extension' support (Thomas Gleixner and Peter Zijlstra): This allows a thread to request a time slice extension when it enters a critical section to avoid contention on a resource when the thread is scheduled out inside of the critical section. - Add fields and constants for time slice extension - Provide static branch for time slice extensions - Add statistics for time slice extensions - Add prctl() to enable time slice extensions - Implement sys_rseq_slice_yield() - Implement syscall entry work for time slice extensions - Implement time slice extension enforcement timer - Reset slice extension when scheduled - Implement rseq_grant_slice_extension() - entry: Hook up rseq time slice extension - selftests: Implement time slice extension test - Allow registering RSEQ with slice extension - Move slice_ext_nsec to debugfs - Lower default slice extension - selftests/rseq: Add rseq slice histogram script Scheduler performance/scalability improvements: - Update rq->avg_idle when a task is moved to an idle CPU, which improves the scalability of various workloads (Shubhang Kaushik) - Reorder fields in 'struct rq' for better caching (Blake Jones) - Fair scheduler SMP NOHZ balancing code speedups (Shrikanth Hegde): - Move checking for nohz cpus after time check - Change likelyhood of nohz.nr_cpus - Remove nohz.nr_cpus and use weight of cpumask instead - Avoid false sharing for sched_clock_irqtime (Wangyang Guo) - Cleanups (Yury Norov): - Drop useless cpumask_empty() in find_energy_efficient_cpu() - Simplify task_numa_find_cpu() - Use cpumask_weight_and() in sched_balance_find_dst_group() DL scheduler updates: - Add a deadline server for sched_ext tasks (by Andrea Righi and Joel Fernandes, with fixes by Peter Zijlstra) RT scheduler updates: - Skip currently executing CPU in rto_next_cpu() (Chen Jinghuang) Entry code updates and performance improvements (Jinjie Ruan) This is part of the scheduler tree in this cycle due to inter- dependencies with the RSEQ based time slice extension work: - Remove unused syscall argument from syscall_trace_enter() - Rework syscall_exit_to_user_mode_work() for architecture reuse - Add arch_ptrace_report_syscall_entry/exit() - Inline syscall_exit_work() and syscall_trace_enter() Scheduler core updates (Peter Zijlstra): - Rework sched_class::wakeup_preempt() and rq_modified_*() - Avoid rq->lock bouncing in sched_balance_newidle() - Rename rcu_dereference_check_sched_domain() => rcu_dereference_sched_domain() - <linux/compiler_types.h>: Add the __signed_scalar_typeof() helper Fair scheduler updates/refactoring (Peter Zijlstra and Ingo Molnar): - Fold the sched_avg update - Change rcu_dereference_check_sched_domain() to rcu-sched - Switch to rcu_dereference_all() - Remove superfluous rcu_read_lock() - Limit hrtick work - Join two #ifdef CONFIG_FAIR_GROUP_SCHED blocks - Clean up comments in 'struct cfs_rq' - Separate se->vlag from se->vprot - Rename cfs_rq::avg_load to cfs_rq::sum_weight - Rename cfs_rq::avg_vruntime to ::sum_w_vruntime & helper functions - Introduce and use the vruntime_cmp() and vruntime_op() wrappers for wrapped-signed aritmetics - Sort out 'blocked_load*' namespace noise Scheduler debugging code updates: - Export hidden tracepoints to modules (Gabriele Monaco) - Convert copy_from_user() + kstrtouint() to kstrtouint_from_user() (Fushuai Wang) - Add assertions to QUEUE_CLASS (Peter Zijlstra) - hrtimer: Fix tracing oddity (Thomas Gleixner) Misc fixes and cleanups: - Re-evaluate scheduling when migrating queued tasks out of throttled cgroups (Zicheng Qu) - Remove task_struct->faults_disabled_mapping (Christoph Hellwig) - Fix math notation errors in avg_vruntime comment (Zhan Xusheng) - sched/cpufreq: Use %pe format for PTR_ERR() printing (zenghongling)" * tag 'sched-core-2026-02-09' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (64 commits) sched: Re-evaluate scheduling when migrating queued tasks out of throttled cgroups sched/cpufreq: Use %pe format for PTR_ERR() printing sched/rt: Skip currently executing CPU in rto_next_cpu() sched/clock: Avoid false sharing for sched_clock_irqtime selftests/sched_ext: Add test for DL server total_bw consistency selftests/sched_ext: Add test for sched_ext dl_server sched/debug: Fix dl_server (re)start conditions sched/debug: Add support to change sched_ext server params sched_ext: Add a DL server for sched_ext tasks sched/debug: Stop and start server based on if it was active sched/debug: Fix updating of ppos on server write ops sched/deadline: Clear the defer params entry: Inline syscall_exit_work() and syscall_trace_enter() entry: Add arch_ptrace_report_syscall_entry/exit() entry: Rework syscall_exit_to_user_mode_work() for architecture reuse entry: Remove unused syscall argument from syscall_trace_enter() sched: remove task_struct->faults_disabled_mapping sched: Update rq->avg_idle when a task is moved to an idle CPU selftests/rseq: Add rseq slice histogram script hrtimer: Fix trace oddity ...
2026-02-10Merge tag 'perf-core-2026-02-09' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull performance event updates from Ingo Molnar: "x86 PMU driver updates: - Add support for the core PMU for Intel Diamond Rapids (DMR) CPUs (Dapeng Mi) Compared to previous iterations of the Intel PMU code, there's been a lot of changes, which center around three main areas: - Introduce the OFF-MODULE RESPONSE (OMR) facility to replace the Off-Core Response (OCR) facility - New PEBS data source encoding layout - Support the new "RDPMC user disable" feature - Likewise, a large series adds uncore PMU support for Intel Diamond Rapids (DMR) CPUs (Zide Chen) This centers around these four main areas: - DMR may have two Integrated I/O and Memory Hub (IMH) dies, separate from the compute tile (CBB) dies. Each CBB and each IMH die has its own discovery domain. - Unlike prior CPUs that retrieve the global discovery table portal exclusively via PCI or MSR, DMR uses PCI for IMH PMON discovery and MSR for CBB PMON discovery. - DMR introduces several new PMON types: SCA, HAMVF, D2D_ULA, UBR, PCIE4, CRS, CPC, ITC, OTC, CMS, and PCIE6. - IIO free-running counters in DMR are MMIO-based, unlike SPR. - Also add support for Add missing PMON units for Intel Panther Lake, and support Nova Lake (NVL), which largely maps to Panther Lake. (Zide Chen) - KVM integration: Add support for mediated vPMUs (by Kan Liang and Sean Christopherson, with fixes and cleanups by Peter Zijlstra, Sandipan Das and Mingwei Zhang) - Add Intel cstate driver to support for Wildcat Lake (WCL) CPUs, which are a low-power variant of Panther Lake (Zide Chen) - Add core, cstate and MSR PMU support for the Airmont NP Intel CPU (aka MaxLinear Lightning Mountain), which maps to the existing Airmont code (Martin Schiller) Performance enhancements: - Speed up kexec shutdown by avoiding unnecessary cross CPU calls (Jan H. Schönherr) - Fix slow perf_event_task_exit() with LBR callstacks (Namhyung Kim) User-space stack unwinding support: - Various cleanups and refactorings in preparation to generalize the unwinding code for other architectures (Jens Remus) Uprobes updates: - Transition from kmap_atomic to kmap_local_page (Keke Ming) - Fix incorrect lockdep condition in filter_chain() (Breno Leitao) - Fix XOL allocation failure for 32-bit tasks (Oleg Nesterov) Misc fixes and cleanups: - s390: Remove kvm_types.h from Kbuild (Randy Dunlap) - x86/intel/uncore: Convert comma to semicolon (Chen Ni) - x86/uncore: Clean up const mismatch (Greg Kroah-Hartman) - x86/ibs: Fix typo in dc_l2tlb_miss comment (Xiang-Bin Shi)" * tag 'perf-core-2026-02-09' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (58 commits) s390: remove kvm_types.h from Kbuild uprobes: Fix incorrect lockdep condition in filter_chain() x86/ibs: Fix typo in dc_l2tlb_miss comment x86/uprobes: Fix XOL allocation failure for 32-bit tasks perf/x86/intel/uncore: Convert comma to semicolon perf/x86/intel: Add support for rdpmc user disable feature perf/x86: Use macros to replace magic numbers in attr_rdpmc perf/x86/intel: Add core PMU support for Novalake perf/x86/intel: Add support for PEBS memory auxiliary info field in NVL perf/x86/intel: Add core PMU support for DMR perf/x86/intel: Add support for PEBS memory auxiliary info field in DMR perf/x86/intel: Support the 4 new OMR MSRs introduced in DMR and NVL perf/core: Fix slow perf_event_task_exit() with LBR callstacks perf/core: Speed up kexec shutdown by avoiding unnecessary cross CPU calls uprobes: use kmap_local_page() for temporary page mappings arm/uprobes: use kmap_local_page() in arch_uprobe_copy_ixol() mips/uprobes: use kmap_local_page() in arch_uprobe_copy_ixol() arm64/uprobes: use kmap_local_page() in arch_uprobe_copy_ixol() riscv/uprobes: use kmap_local_page() in arch_uprobe_copy_ixol() perf/x86/intel/uncore: Add Nova Lake support ...
2026-02-10Merge tag 'bpf-next-7.0' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next Pull bpf updates from Alexei Starovoitov: - Support associating BPF program with struct_ops (Amery Hung) - Switch BPF local storage to rqspinlock and remove recursion detection counters which were causing false positives (Amery Hung) - Fix live registers marking for indirect jumps (Anton Protopopov) - Introduce execution context detection BPF helpers (Changwoo Min) - Improve verifier precision for 32bit sign extension pattern (Cupertino Miranda) - Optimize BTF type lookup by sorting vmlinux BTF and doing binary search (Donglin Peng) - Allow states pruning for misc/invalid slots in iterator loops (Eduard Zingerman) - In preparation for ASAN support in BPF arenas teach libbpf to move global BPF variables to the end of the region and enable arena kfuncs while holding locks (Emil Tsalapatis) - Introduce support for implicit arguments in kfuncs and migrate a number of them to new API. This is a prerequisite for cgroup sub-schedulers in sched-ext (Ihor Solodrai) - Fix incorrect copied_seq calculation in sockmap (Jiayuan Chen) - Fix ORC stack unwind from kprobe_multi (Jiri Olsa) - Speed up fentry attach by using single ftrace direct ops in BPF trampolines (Jiri Olsa) - Require frozen map for calculating map hash (KP Singh) - Fix lock entry creation in TAS fallback in rqspinlock (Kumar Kartikeya Dwivedi) - Allow user space to select cpu in lookup/update operations on per-cpu array and hash maps (Leon Hwang) - Make kfuncs return trusted pointers by default (Matt Bobrowski) - Introduce "fsession" support where single BPF program is executed upon entry and exit from traced kernel function (Menglong Dong) - Allow bpf_timer and bpf_wq use in all programs types (Mykyta Yatsenko, Andrii Nakryiko, Kumar Kartikeya Dwivedi, Alexei Starovoitov) - Make KF_TRUSTED_ARGS the default for all kfuncs and clean up their definition across the tree (Puranjay Mohan) - Allow BPF arena calls from non-sleepable context (Puranjay Mohan) - Improve register id comparison logic in the verifier and extend linked registers with negative offsets (Puranjay Mohan) - In preparation for BPF-OOM introduce kfuncs to access memcg events (Roman Gushchin) - Use CFI compatible destructor kfunc type (Sami Tolvanen) - Add bitwise tracking for BPF_END in the verifier (Tianci Cao) - Add range tracking for BPF_DIV and BPF_MOD in the verifier (Yazhou Tang) - Make BPF selftests work with 64k page size (Yonghong Song) * tag 'bpf-next-7.0' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (268 commits) selftests/bpf: Fix outdated test on storage->smap selftests/bpf: Choose another percpu variable in bpf for btf_dump test selftests/bpf: Remove test_task_storage_map_stress_lookup selftests/bpf: Update task_local_storage/task_storage_nodeadlock test selftests/bpf: Update task_local_storage/recursion test selftests/bpf: Update sk_storage_omem_uncharge test bpf: Switch to bpf_selem_unlink_nofail in bpf_local_storage_{map_free, destroy} bpf: Support lockless unlink when freeing map or local storage bpf: Prepare for bpf_selem_unlink_nofail() bpf: Remove unused percpu counter from bpf_local_storage_map_free bpf: Remove cgroup local storage percpu counter bpf: Remove task local storage percpu counter bpf: Change local_storage->lock and b->lock to rqspinlock bpf: Convert bpf_selem_unlink to failable bpf: Convert bpf_selem_link_map to failable bpf: Convert bpf_selem_unlink_map to failable bpf: Select bpf_local_storage_map_bucket based on bpf_local_storage selftests/xsk: fix number of Tx frags in invalid packet selftests/xsk: properly handle batch ending in the middle of a packet bpf: Prevent reentrance into call_rcu_tasks_trace() ...
2026-02-10Merge tag 'hardening-v7.0-rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux Pull hardening updates from Kees Cook: "Mostly small cleanups and various scattered annotations and flex array warning fixes that we reviewed by unlanded in other trees. Introduces new annotation for expanding counted_by to pointer members, now that compiler behavior between GCC and Clang has been normalized. - Various missed __counted_by annotations (Thorsten Blum) - Various missed -Wflex-array-member-not-at-end fixes (Gustavo A. R. Silva) - Avoid leftover tempfiles for interrupted compile-time FORTIFY tests (Nicolas Schier) - Remove non-existant CONFIG_UBSAN_REPORT_FULL from docs (Stefan Wiehler) - fortify: Use C arithmetic not FIELD_xxx() in FORTIFY_REASON defines (David Laight) - Add __counted_by_ptr attribute, tests, and first user (Bill Wendling, Kees Cook) - Update MAINTAINERS file to make hardening section not include pstore" * tag 'hardening-v7.0-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux: MAINTAINERS: pstore: Remove L: entry nfp: tls: Avoid -Wflex-array-member-not-at-end warnings carl9170: Avoid -Wflex-array-member-not-at-end warning coredump: Use __counted_by_ptr for struct core_name::corename lkdtm/bugs: Add __counted_by_ptr() test PTR_BOUNDS compiler_types.h: Attributes: Add __counted_by_ptr macro fortify: Cleanup temp file also on non-successful exit fortify: Rename temporary file to match ignore pattern fortify: Use C arithmetic not FIELD_xxx() in FORTIFY_REASON defines ecryptfs: Annotate struct ecryptfs_message with __counted_by fs/xattr: Annotate struct simple_xattr with __counted_by crypto: af_alg - Annotate struct af_alg_iv with __counted_by Kconfig.ubsan: Remove CONFIG_UBSAN_REPORT_FULL from documentation drm/nouveau: fifo: Avoid -Wflex-array-member-not-at-end warning
2026-02-09Merge tag 'kthread-for-7.0' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/frederic/linux-dynticks Pull kthread updates from Frederic Weisbecker: "The kthread code provides an infrastructure which manages the preferred affinity of unbound kthreads (node or custom cpumask) against housekeeping (CPU isolation) constraints and CPU hotplug events. One crucial missing piece is the handling of cpuset: when an isolated partition is created, deleted, or its CPUs updated, all the unbound kthreads in the top cpuset become indifferently affine to _all_ the non-isolated CPUs, possibly breaking their preferred affinity along the way. Solve this with performing the kthreads affinity update from cpuset to the kthreads consolidated relevant code instead so that preferred affinities are honoured and applied against the updated cpuset isolated partitions. The dispatch of the new isolated cpumasks to timers, workqueues and kthreads is performed by housekeeping, as per the nice Tejun's suggestion. As a welcome side effect, HK_TYPE_DOMAIN then integrates both the set from boot defined domain isolation (through isolcpus=) and cpuset isolated partitions. Housekeeping cpumasks are now modifiable with a specific RCU based synchronization. A big step toward making nohz_full= also mutable through cpuset in the future" * tag 'kthread-for-7.0' of git://git.kernel.org/pub/scm/linux/kernel/git/frederic/linux-dynticks: (33 commits) doc: Add housekeeping documentation kthread: Document kthread_affine_preferred() kthread: Comment on the purpose and placement of kthread_affine_node() call kthread: Honour kthreads preferred affinity after cpuset changes sched/arm64: Move fallback task cpumask to HK_TYPE_DOMAIN sched: Switch the fallback task allowed cpumask to HK_TYPE_DOMAIN kthread: Rely on HK_TYPE_DOMAIN for preferred affinity management kthread: Include kthreadd to the managed affinity list kthread: Include unbound kthreads in the managed affinity list kthread: Refine naming of affinity related fields PCI: Remove superfluous HK_TYPE_WQ check sched/isolation: Remove HK_TYPE_TICK test from cpu_is_isolated() cpuset: Remove cpuset_cpu_is_isolated() timers/migration: Remove superfluous cpuset isolation test cpuset: Propagate cpuset isolation update to timers through housekeeping cpuset: Propagate cpuset isolation update to workqueue through housekeeping PCI: Flush PCI probe workqueue on cpuset isolated partition change sched/isolation: Flush vmstat workqueues on cpuset isolated partition change sched/isolation: Flush memcg workqueues on cpuset isolated partition change cpuset: Update HK_TYPE_DOMAIN cpumask from cpuset ...
2026-02-09Merge tag 'vfs-7.0-rc1.misc' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs Pull misc vfs updates from Christian Brauner: "This contains a mix of VFS cleanups, performance improvements, API fixes, documentation, and a deprecation notice. Scalability and performance: - Rework pid allocation to only take pidmap_lock once instead of twice during alloc_pid(), improving thread creation/teardown throughput by 10-16% depending on false-sharing luck. Pad the namespace refcount to reduce false-sharing - Track file lock presence via a flag in ->i_opflags instead of reading ->i_flctx, avoiding false-sharing with ->i_readcount on open/close hot paths. Measured 4-16% improvement on 24-core open-in-a-loop benchmarks - Use a consume fence in locks_inode_context() to match the store-release/load-consume idiom, eliminating a hardware fence on some architectures - Annotate cdev_lock with __cacheline_aligned_in_smp to prevent false-sharing - Remove a redundant DCACHE_MANAGED_DENTRY check in __follow_mount_rcu() that never fires since the caller already verifies it, eliminating a 100% mispredicted branch - Fix a 100% mispredicted likely() in devcgroup_inode_permission() that became wrong after a prior code reorder Bug fixes and correctness: - Make insert_inode_locked() wait for inode destruction instead of skipping, fixing a corner case where two matching inodes could exist in the hash - Move f_mode initialization before file_ref_init() in alloc_file() to respect the SLAB_TYPESAFE_BY_RCU ordering contract - Add a WARN_ON_ONCE guard in try_to_free_buffers() for folios with no buffers attached, preventing a null pointer dereference when AS_RELEASE_ALWAYS is set but no release_folio op exists - Fix select restart_block to store end_time as timespec64, avoiding truncation of tv_sec on 32-bit architectures - Make dump_inode() use get_kernel_nofault() to safely access inode and superblock fields, matching the dump_mapping() pattern API modernization: - Make posix_acl_to_xattr() allocate the buffer internally since every single caller was doing it anyway. Reduces boilerplate and unnecessary error checking across ~15 filesystems - Replace deprecated simple_strtoul() with kstrtoul() for the ihash_entries, dhash_entries, mhash_entries, and mphash_entries boot parameters, adding proper error handling - Convert chardev code to use guard(mutex) and __free(kfree) cleanup patterns - Replace min_t() with min() or umin() in VFS code to avoid silently truncating unsigned long to unsigned int - Gate LOOKUP_RCU assertions behind CONFIG_DEBUG_VFS since callers already check the flag Deprecation: - Begin deprecating legacy BSD process accounting (acct(2)). The interface has numerous footguns and better alternatives exist (eBPF) Documentation: - Fix and complete kernel-doc for struct export_operations, removing duplicated documentation between ReST and source - Fix kernel-doc warnings for __start_dirop() and ilookup5_nowait() Testing: - Add a kunit test for initramfs cpio handling of entries with filesize > PATH_MAX Misc: - Add missing <linux/init_task.h> include in fs_struct.c" * tag 'vfs-7.0-rc1.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: (28 commits) posix_acl: make posix_acl_to_xattr() alloc the buffer fs: make insert_inode_locked() wait for inode destruction initramfs_test: kunit test for cpio.filesize > PATH_MAX fs: improve dump_inode() to safely access inode fields fs: add <linux/init_task.h> for 'init_fs' docs: exportfs: Use source code struct documentation fs: move initializing f_mode before file_ref_init() exportfs: Complete kernel-doc for struct export_operations exportfs: Mark struct export_operations functions at kernel-doc exportfs: Fix kernel-doc output for get_name() acct(2): begin the deprecation of legacy BSD process accounting device_cgroup: remove branch hint after code refactor VFS: fix __start_dirop() kernel-doc warnings fs: Describe @isnew parameter in ilookup5_nowait() fs/namei: Remove redundant DCACHE_MANAGED_DENTRY check in __follow_mount_rcu fs: only assert on LOOKUP_RCU when built with CONFIG_DEBUG_VFS select: store end_time as timespec64 in restart block chardev: Switch to guard(mutex) and __free(kfree) namespace: Replace simple_strtoul with kstrtoul to parse boot params dcache: Replace simple_strtoul with kstrtoul in set_dhash_entries ...
2026-02-09Merge tag 'vfs-7.0-rc1.nullfs' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs Pull vfs nullfs update from Christian Brauner: "Add a completely catatonic minimal pseudo filesystem called "nullfs" and make pivot_root() work in the initramfs. Currently pivot_root() does not work on the real rootfs because it cannot be unmounted. Userspace has to recursively delete initramfs contents manually before continuing boot, using the fragile switch_root sequence (overmount + chroot). Add nullfs, a minimal immutable filesystem that serves as the true root of the mount hierarchy. The mutable rootfs (tmpfs/ramfs) is mounted on top of it. This allows userspace to simply: chdir(new_root); pivot_root(".", "."); umount2(".", MNT_DETACH); without the traditional switch_root workarounds. systemd already handles this correctly. It tries pivot_root() first and falls back to MS_MOVE only when that fails. This also means rootfs mounts in unprivileged namespaces no longer need MNT_LOCKED, since the immutable nullfs guarantees nothing can be revealed by unmounting the covering mount. nullfs is a single-instance filesystem (get_tree_single()) marked SB_NOUSER | SB_I_NOEXEC | SB_I_NODEV with an immutable empty root directory. This means sooner or later it can be used to overmount other directories to hide their contents without any additional protection needed. We enable it unconditionally. If we see any real regression we'll hide it behind a boot option. nullfs has extensions beyond this in the future. It will serve as a concept to support the creation of completely empty mount namespaces - which is work coming up in the next cycle" * tag 'vfs-7.0-rc1.nullfs' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: fs: use nullfs unconditionally as the real rootfs docs: mention nullfs fs: add immutable rootfs fs: add init_pivot_root() fs: ensure that internal tmpfs mount gets mount id zero
2026-02-09Merge tag 'vfs-7.0-rc1.initrd' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs Pull vfs initrd removal from Christian Brauner: "Remove the deprecated linuxrc-based initrd code path and related dead code. The linuxrc initrd path was deprecated in 2020 and this series completes its removal. If we see real-life regressions we'll revert. The core change removes handle_initrd() and init_linuxrc() — the entire flow that ran /linuxrc from an initrd, pivoted roots, and handed off to the real root filesystem. With that gone, initrd_load() becomes void (no longer short-circuits prepare_namespace()), rd_load_image() is simplified to always load /initrd.image instead of taking a path, and rd_load_disk() is deleted. The /proc/sys/kernel/real-root-dev sysctl and its backing variable are removed since they only existed for linuxrc to communicate the real root device back to the kernel. The no-op load_ramdisk= and prompt_ramdisk= parameters are dropped, and noinitrd and ramdisk_start= gain deprecation warnings. Initramfs is entirely unaffected. The non-linuxrc initrd path (root=/dev/ram0) is preserved but now carries a deprecation warning targeting January 2027 removal" * tag 'vfs-7.0-rc1.initrd' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: init: remove /proc/sys/kernel/real-root-dev initrd: remove deprecated code path (linuxrc) init: remove deprecated "load_ramdisk" and "prompt_ramdisk" command line parameters
2026-02-03cpuset: Propagate cpuset isolation update to workqueue through housekeepingFrederic Weisbecker
Until now, cpuset would propagate isolated partition changes to workqueues so that unbound workers get properly reaffined. Since housekeeping now centralizes, synchronize and propagates isolation cpumask changes, perform the work from that subsystem for consolidation and consistency purposes. For simplification purpose, the target function is adapted to take the new housekeeping mask instead of the isolated mask. Suggested-by: Tejun Heo <tj@kernel.org> Signed-off-by: Frederic Weisbecker <frederic@kernel.org> Reviewed-by: Waiman Long <longman@redhat.com> Acked-by: Tejun Heo <tj@kernel.org> Cc: "Michal Koutný" <mkoutny@suse.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Lai Jiangshan <jiangshanlai@gmail.com> Cc: Marco Crivellari <marco.crivellari@suse.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Tejun Heo <tj@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Waiman Long <longman@redhat.com> Cc: cgroups@vger.kernel.org
2026-01-26arch, mm: consolidate initialization of nodes, zones and memory mapMike Rapoport (Microsoft)
To initialize node, zone and memory map data structures every architecture calls free_area_init() during setup_arch() and passes it an array of zone limits. Beside code duplication it creates "interesting" ordering cases between allocation and initialization of hugetlb and the memory map. Some architectures allocate hugetlb pages very early in setup_arch() in certain cases, some only create hugetlb CMA areas in setup_arch() and sometimes hugetlb allocations happen mm_core_init(). With arch_zone_limits_init() helper available now on all architectures it is no longer necessary to call free_area_init() from architecture setup code. Rather core MM initialization can call arch_zone_limits_init() in a single place. This allows to unify ordering of hugetlb vs memory map allocation and initialization. Remove the call to free_area_init() from architecture specific code and place it in a new mm_core_init_early() function that is called immediately after setup_arch(). After this refactoring it is possible to consolidate hugetlb allocations and eliminate differences in ordering of hugetlb and memory map initialization among different architectures. As the first step of this consolidation move hugetlb_bootmem_alloc() to mm_core_early_init(). Link: https://lkml.kernel.org/r/20260111082105.290734-24-rppt@kernel.org Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Alex Shi <alexs@kernel.org> Cc: Andreas Larsson <andreas@gaisler.com> Cc: "Borislav Petkov (AMD)" <bp@alien8.de> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: David Hildenbrand <david@kernel.org> Cc: David S. Miller <davem@davemloft.net> Cc: Dinh Nguyen <dinguyen@kernel.org> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Guo Ren <guoren@kernel.org> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Helge Deller <deller@gmx.de> Cc: Huacai Chen <chenhuacai@kernel.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Johannes Berg <johannes@sipsolutions.net> Cc: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Klara Modin <klarasmodin@gmail.com> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Magnus Lindholm <linmag7@gmail.com> Cc: Matt Turner <mattst88@gmail.com> Cc: Max Filippov <jcmvbkbc@gmail.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Hocko <mhocko@suse.com> Cc: Michal Simek <monstr@monstr.eu> Cc: Muchun Song <muchun.song@linux.dev> Cc: Oscar Salvador <osalvador@suse.de> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Pratyush Yadav <pratyush@kernel.org> Cc: Richard Weinberger <richard@nod.at> Cc: "Ritesh Harjani (IBM)" <ritesh.list@gmail.com> Cc: Russell King <linux@armlinux.org.uk> Cc: Stafford Horne <shorne@gmail.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Vineet Gupta <vgupta@kernel.org> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-01-26init/main: read bootconfig header with get_unaligned_le32()Sun Jian
get_boot_config_from_initrd() scans up to 3 bytes before initrd_end to handle GRUB 4-byte alignment. As a result, the bootconfig header immediately preceding the magic may be unaligned. Read the size and checksum fields with get_unaligned_le32() instead of casting to u32 * and using le32_to_cpu(), avoiding potential unaligned access and silencing sparse "cast to restricted __le32" warnings. Sparse warnings (gcc + C=1): init/main.c:292:16: warning: cast to restricted __le32 init/main.c:293:16: warning: cast to restricted __le32 No functional change intended. Link: https://lkml.kernel.org/r/20260113101532.1630770-1-sun.jian.kdev@gmail.com Signed-off-by: Sun Jian <sun.jian.kdev@gmail.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Thomas Gleixner <tglx@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-01-26init/main.c: check if rdinit was explicitly set before printing warningLillian Berry
The rdinit parameter is set by default, and attempted during boot even if not specified in the command line. Only print the warning about rdinit being inaccessible if the rdinit value was found in command line; it's just noise otherwise. [akpm@linux-foundation.org: move ramdisk_execute_command_set into __initdata] Link: https://lkml.kernel.org/r/20260111125635.53682-1-lillian@star-ark.net Signed-off-by: Lillian Berry <lillian@star-ark.net> Cc: Ahmad Fatoum <a.fatoum@pengutronix.de> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Douglas Anderson <dianders@chromium.org> Cc: Francesco Valla <francesco@valla.it> Cc: Guo Weikang <guoweikang.kernel@gmail.com> Cc: Huacai Chen <chenhuacai@kernel.org> Cc: Huan Yang <link@vivo.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: "Mike Rapoport (Microsoft)" <rppt@kernel.org> Cc: Sascha Hauer <kernel@pengutronix.de> Cc: Thomas Gleixner <tglx@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-01-22sched: remove task_struct->faults_disabled_mappingChristoph Hellwig
This reverts commit 2b69987be575 ("sched: Add task_struct->faults_disabled_mapping"), which added this field without review or maintainer signoff. With bcachefs removed from the tree it is also unused now. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://patch.msgid.link/20260122085223.487092-1-hch@lst.de
2026-01-22rseq: Add fields and constants for time slice extensionThomas Gleixner
Aside of a Kconfig knob add the following items: - Two flag bits for the rseq user space ABI, which allow user space to query the availability and enablement without a syscall. - A new member to the user space ABI struct rseq, which is going to be used to communicate request and grant between kernel and user space. - A rseq state struct to hold the kernel state of this - Documentation of the new mechanism Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://patch.msgid.link/20251215155708.669472597@linutronix.de
2026-01-17compiler_types.h: Attributes: Add __counted_by_ptr macroBill Wendling
Introduce __counted_by_ptr(), which works like __counted_by(), but for pointer struct members. struct foo { int a, b, c; char *buffer __counted_by_ptr(bytes); short nr_bars; struct bar *bars __counted_by_ptr(nr_bars); size_t bytes; }; Because "counted_by" can only be applied to pointer members in very recent compiler versions, its application ends up needing to be distinct from flexibe array "counted_by" annotations, hence a separate macro. This is a reworking of Kees' previous patch [1]. Link: https://lore.kernel.org/all/20251020220118.1226740-1-kees@kernel.org/ [1] Co-developed-by: Kees Cook <kees@kernel.org> Signed-off-by: Bill Wendling <morbo@google.com> Link: https://patch.msgid.link/20260116005838.2419118-1-morbo@google.com Signed-off-by: Kees Cook <kees@kernel.org>
2026-01-16kbuild: uapi: drop dependency on CC_CAN_LINKThomas Weißschuh
The header tests try to compile each header. Some UAPI headers depend on libc headers so they need a full userspace toolchain to build. This dependency is expressed in kconfig as a dependency on CC_CAN_LINK. Many kernel builds do not satisfy CC_CAN_LINK as they only use a minimal kernel (cross-) compiler. In those configurations the UAPI headers are not tested at all. However most UAPI headers do not even depend on any libc headers, and such dependencies are undesired in any case. Also the static analysis performed by headers_check.pl does not need CC_CAN_LINK. Drop the hard dependency on CC_CAN_LINK and instead skip the affected compilation step for exactly those headers which require libc. Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de> Link: https://patch.msgid.link/20251223-uapi-nostdinc-v1-5-d91545d794f7@linutronix.de Signed-off-by: Nathan Chancellor <nathan@kernel.org>
2026-01-14initramfs_test: kunit test for cpio.filesize > PATH_MAXDavid Disseldorp
initramfs unpack skips over cpio entries where namesize > PATH_MAX, instead of returning an error. Add coverage for this behaviour. Signed-off-by: David Disseldorp <ddiss@suse.de> Link: https://patch.msgid.link/20260114135051.4943-2-ddiss@suse.de Signed-off-by: Christian Brauner <brauner@kernel.org>
2026-01-14acct(2): begin the deprecation of legacy BSD process accountingJeff Layton
As Christian points out [1], even though it's privileged, this interface has a lot of footguns. There are better options these days (e.g. eBPF), so it would be good to start discouraging its use and mark it as deprecated. [1]: https://lore.kernel.org/linux-fsdevel/20250212-giert-spannend-8893f1eaba7d@brauner/ Signed-off-by: Jeff Layton <jlayton@kernel.org> Link: https://patch.msgid.link/20260106-bsd-acct-v1-1-d15564b52c83@kernel.org Signed-off-by: Christian Brauner <brauner@kernel.org>
2026-01-14fs: use nullfs unconditionally as the real rootfsChristian Brauner
Remove the "nullfs_rootfs" boot parameter and simply always use nullfs. The mutable rootfs will be mounted on top of it. Systems that don't use pivot_root() to pivot away from the real rootfs will have an additional mount stick around but that shouldn't be a problem at all. If it is we'll rever this commit. This also simplifies the boot process and removes the need for the traditional switch_root workarounds. Suggested-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Christian Brauner <brauner@kernel.org>
2026-01-12init: remove /proc/sys/kernel/real-root-devAskar Safin
It is not used anymore. Signed-off-by: Askar Safin <safinaskar@gmail.com> Link: https://patch.msgid.link/20251119222407.3333257-4-safinaskar@gmail.com Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Christian Brauner <brauner@kernel.org>
2026-01-12initrd: remove deprecated code path (linuxrc)Askar Safin
Remove linuxrc initrd code path, which was deprecated in 2020. Initramfs and (non-initial) RAM disks (i. e. brd) still work. Both built-in and bootloader-supplied initramfs still work. Non-linuxrc initrd code path (i. e. using /dev/ram as final root filesystem) still works, but I put deprecation message into it. Also I deprecate command line parameters "noinitrd" and "ramdisk_start=". Signed-off-by: Askar Safin <safinaskar@gmail.com> Link: https://patch.msgid.link/20251119222407.3333257-3-safinaskar@gmail.com Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Christian Brauner <brauner@kernel.org>