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2025-12-06Merge tag 'mm-nonmm-stable-2025-12-06-11-14' of ↵Linus Torvalds3-6/+124
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Pull non-MM updates from Andrew Morton: - "panic: sys_info: Refactor and fix a potential issue" (Andy Shevchenko) fixes a build issue and does some cleanup in ib/sys_info.c - "Implement mul_u64_u64_div_u64_roundup()" (David Laight) enhances the 64-bit math code on behalf of a PWM driver and beefs up the test module for these library functions - "scripts/gdb/symbols: make BPF debug info available to GDB" (Ilya Leoshkevich) makes BPF symbol names, sizes, and line numbers available to the GDB debugger - "Enable hung_task and lockup cases to dump system info on demand" (Feng Tang) adds a sysctl which can be used to cause additional info dumping when the hung-task and lockup detectors fire - "lib/base64: add generic encoder/decoder, migrate users" (Kuan-Wei Chiu) adds a general base64 encoder/decoder to lib/ and migrates several users away from their private implementations - "rbree: inline rb_first() and rb_last()" (Eric Dumazet) makes TCP a little faster - "liveupdate: Rework KHO for in-kernel users" (Pasha Tatashin) reworks the KEXEC Handover interfaces in preparation for Live Update Orchestrator (LUO), and possibly for other future clients - "kho: simplify state machine and enable dynamic updates" (Pasha Tatashin) increases the flexibility of KEXEC Handover. Also preparation for LUO - "Live Update Orchestrator" (Pasha Tatashin) is a major new feature targeted at cloud environments. Quoting the cover letter: This series introduces the Live Update Orchestrator, a kernel subsystem designed to facilitate live kernel updates using a kexec-based reboot. This capability is critical for cloud environments, allowing hypervisors to be updated with minimal downtime for running virtual machines. LUO achieves this by preserving the state of selected resources, such as memory, devices and their dependencies, across the kernel transition. As a key feature, this series includes support for preserving memfd file descriptors, which allows critical in-memory data, such as guest RAM or any other large memory region, to be maintained in RAM across the kexec reboot. Mike Rappaport merits a mention here, for his extensive review and testing work. - "kexec: reorganize kexec and kdump sysfs" (Sourabh Jain) moves the kexec and kdump sysfs entries from /sys/kernel/ to /sys/kernel/kexec/ and adds back-compatibility symlinks which can hopefully be removed one day - "kho: fixes for vmalloc restoration" (Mike Rapoport) fixes a BUG which was being hit during KHO restoration of vmalloc() regions * tag 'mm-nonmm-stable-2025-12-06-11-14' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (139 commits) calibrate: update header inclusion Reinstate "resource: avoid unnecessary lookups in find_next_iomem_res()" vmcoreinfo: track and log recoverable hardware errors kho: fix restoring of contiguous ranges of order-0 pages kho: kho_restore_vmalloc: fix initialization of pages array MAINTAINERS: TPM DEVICE DRIVER: update the W-tag init: replace simple_strtoul with kstrtoul to improve lpj_setup KHO: fix boot failure due to kmemleak access to non-PRESENT pages Documentation/ABI: new kexec and kdump sysfs interface Documentation/ABI: mark old kexec sysfs deprecated kexec: move sysfs entries to /sys/kernel/kexec test_kho: always print restore status kho: free chunks using free_page() instead of kfree() selftests/liveupdate: add kexec test for multiple and empty sessions selftests/liveupdate: add simple kexec-based selftest for LUO selftests/liveupdate: add userspace API selftests docs: add documentation for memfd preservation via LUO mm: memfd_luo: allow preserving memfd liveupdate: luo_file: add private argument to store runtime state mm: shmem: export some functions to internal.h ...
2025-12-05Merge tag 'pull-persistency' of ↵Linus Torvalds1-1/+1
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull persistent dentry infrastructure and conversion from Al Viro: "Some filesystems use a kinda-sorta controlled dentry refcount leak to pin dentries of created objects in dcache (and undo it when removing those). A reference is grabbed and not released, but it's not actually _stored_ anywhere. That works, but it's hard to follow and verify; among other things, we have no way to tell _which_ of the increments is intended to be an unpaired one. Worse, on removal we need to decide whether the reference had already been dropped, which can be non-trivial if that removal is on umount and we need to figure out if this dentry is pinned due to e.g. unlink() not done. Usually that is handled by using kill_litter_super() as ->kill_sb(), but there are open-coded special cases of the same (consider e.g. /proc/self). Things get simpler if we introduce a new dentry flag (DCACHE_PERSISTENT) marking those "leaked" dentries. Having it set claims responsibility for +1 in refcount. The end result this series is aiming for: - get these unbalanced dget() and dput() replaced with new primitives that would, in addition to adjusting refcount, set and clear persistency flag. - instead of having kill_litter_super() mess with removing the remaining "leaked" references (e.g. for all tmpfs files that hadn't been removed prior to umount), have the regular shrink_dcache_for_umount() strip DCACHE_PERSISTENT of all dentries, dropping the corresponding reference if it had been set. After that kill_litter_super() becomes an equivalent of kill_anon_super(). Doing that in a single step is not feasible - it would affect too many places in too many filesystems. It has to be split into a series. This work has really started early in 2024; quite a few preliminary pieces have already gone into mainline. This chunk is finally getting to the meat of that stuff - infrastructure and most of the conversions to it. Some pieces are still sitting in the local branches, but the bulk of that stuff is here" * tag 'pull-persistency' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (54 commits) d_make_discardable(): warn if given a non-persistent dentry kill securityfs_recursive_remove() convert securityfs get rid of kill_litter_super() convert rust_binderfs convert nfsctl convert rpc_pipefs convert hypfs hypfs: swich hypfs_create_u64() to returning int hypfs: switch hypfs_create_str() to returning int hypfs: don't pin dentries twice convert gadgetfs gadgetfs: switch to simple_remove_by_name() convert functionfs functionfs: switch to simple_remove_by_name() functionfs: fix the open/removal races functionfs: need to cancel ->reset_work in ->kill_sb() functionfs: don't bother with ffs->ref in ffs_data_{opened,closed}() functionfs: don't abuse ffs_data_closed() on fs shutdown convert selinuxfs ...
2025-12-04Merge tag 'drm-next-2025-12-03' of https://gitlab.freedesktop.org/drm/kernelLinus Torvalds1-0/+3
Pull drm updates from Dave Airlie: "There was a rather late merge of a new color pipeline feature, that some userspace projects are blocked on, and has seen a lot of work in amdgpu. This should have seen some time in -next. There is additional support for this for Intel, that if it arrives in the next day or two I'll pass it on in another pull request and you can decide if you want to take it. Highlights: - Arm Ethos NPU accelerator driver - new DRM color pipeline support - amdgpu will now run discrete SI/CIK cards instead of radeon, which enables vulkan support in userspace - msm gets gen8 gpu support - initial Xe3P support in xe Full detail summary: New driver: - Arm Ethos-U65/U85 accel driver Core: - support the drm color pipeline in vkms/amdgfx - add support for drm colorop pipeline - add COLOR PIPELINE plane property - add DRM_CLIENT_CAP_PLANE_COLOR_PIPELINE - throttle dirty worker with vblank - use drm_for_each_bridge_in_chain_scoped in drm's bridge code - Ensure drm_client_modeset tests are enabled in UML - add simulated vblank interrupt - use in drivers - dumb buffer sizing helper - move freeing of drm client memory to driver - crtc sharpness strength property - stop using system_wq in scheduler/drivers - support emergency restore in drm-client Rust: - make slice::as_flattened usable on all supported rustc - add FromBytes::from_bytes_prefix() method - remove redundant device ptr from Rust GEM object - Change how AlwaysRefCounted is implemented for GEM objects gpuvm: - Add deferred vm_bo cleanup to GPUVM (for rust) atomic: - cleanup and improve state handling interfaces buddy: - optimize block management dma-buf: - heaps: Create heap per CMA reserved location - improve userspace documentation dp: - add POST_LT_ADJ_REQ training sequence - DPCD dSC quirk for synaptics panamera devices - helpers to query branch DSC max throughput ttm: - Rename ttm_bo_put to ttm_bo_fini - allow page protection flags on risc-v - rework pipelined eviction fence handling amdgpu: - enable amdgpu by default for SI/CI dGPUs - enable DC by default on SI - refactor CIK/SI enablement - add ABM KMS property - Re-enable DM idle optimizations - DC Analog encoders support - Powerplay fixes for fiji/iceland - Enable DC on bonaire by default - HMM cleanup - Add new RAS framework - DML2.1 updates - YCbCr420 fixes - DC FP fixes - DMUB fixes - LTTPR fixes - DTBCLK fixes - DMU cursor offload handling - Userq validation improvements - Unify shutdown callback handling - Suspend improvements - Power limit code cleanup - SR-IOV fixes - AUX backlight fixes - DCN 3.5 fixes - HDMI compliance fixes - DCN 4.0.1 cursor updates - DCN interrupt fix - DC KMS full update improvements - Add additional HDCP traces - DCN 3.2 fixes - DP MST fixes - Add support for new SR-IOV mailbox interface - UQ reset support - HDP flush rework - VCE1 support amdkfd: - HMM cleanups - Relax checks on save area overallocations - Fix GPU mappings after prefetch radeon: - refactor CIK/SI enablement xe: - Initial Xe3P support - panic support on VRAM for display - fix stolen size check - Loosen used tracking restriction - New SR-IOV debugfs structure and debugfs updates - Hide the GPU madvise flag behind a VM_BIND flag - Always expose VRAM provisioning data on discrete GPUs - Allow VRAM mappings for userptr when used with SVM - Allow pinning of p2p dma-buf - Use per-tile debugfs where appropriate - Add documentation for Execution Queues - PF improvements - VF migration recovery redesign work - User / Kernel VRAM partitioning - Update Tile-based messages - Allow configfs to disable specific GT types - VF provisioning and migration improvements - use SVM range helpers in PT layer - Initial CRI support - access VF registers using dedicated MMIO view - limit number of jobs per exec queue - add sriov_admin sysfs tree - more crescent island specific support - debugfs residency counter - SRIOV migration work - runtime registers for GFX 35 i915: - add initial Xe3p_LPD display version 35 support - Enable LNL+ content adaptive sharpness filter - Use optimized VRR guardband - Enable Xe3p LT PHY - enable FBC support for Xe3p_LPD display - add display 30.02 firmware support - refactor SKL+ watermark latency setup - refactor fbdev handling - call i915/xe runtime PM via function pointers - refactor i915/xe stolen memory/display interfaces - use display version instead of gfx version in display code - extend i915_display_info with Type-C port details - lots of display cleanups/refactorings - set O_LARGEFILE in __create_shmem - skuip guc communication warning on reset - fix time conversions - defeature DRRS on LNL+ - refactor intel_frontbuffer split between i915/xe/display - convert inteL_rom interfaces to struct drm_device - unify display register polling interfaces - aovid lock inversion when pinning to GGTT on CHV/BXT+VTD panel: - Add KD116N3730A08/A12, chromebook mt8189 - JT101TM023, LQ079L1SX01, - GLD070WX3-SL01 MIPI DSI - Samsung LTL106AL0, Samsung LTL106AL01 - Raystar RFF500F-AWH-DNN - Winstar WF70A8SYJHLNGA - Wanchanglong w552946aaa - Samsung SOFEF00 - Lenovo X13s panel - ilitek-ili9881c - add rpi 5" support - visionx-rm69299 - add backlight support - edp - support AUI B116XAN02.0 bridge: - improve ref counting - ti-sn65dsi86 - add support for DP mode with HPD - synopsis: support CEC, init timer with correct freq - ASL CS5263 DP-to-HDMI bridge support nova-core: - introduce bitfield! macro - introduce safe integer converters - GSP inits to fully booted state on Ampere - Use more future-proof register for GPU identification nova-drm: - select NOVA_CORE - 64-bit only nouveau: - improve reclocking on tegra 186+ - add large page and compression support msm: - GPU: - Gen8 support: A840 (Kaanapali) and X2-85 (Glymur) - A612 support - MDSS: - Added support for Glymur and QCS8300 platforms - DPU: - Enabled Quad-Pipe support, unlocking higher resolutions support - Added support for Glymur platform - Documented DPU on QCS8300 platform as supported - DisplayPort: - Added support for Glymur platform - Added support lame remapping inside DP block - Documented DisplayPort controller on QCS8300 and SM6150/QCS615 as supported tegra: - NVJPG driver panfrost: - display JM contexts over debugfs - export JM contexts to userspace - improve error and job handling panthor: - support custom ASN_HASH for mt8196 - support mali-G1 GPU - flush shmem write before mapping buffers uncached - make timeout per-queue instead of per-job mediatek: - MT8195/88 HDMIv2/DDCv2 support rockchip: - dsi: add support for RK3368 amdxdna: - enhance runtime PM - last hardware error reading uapi - support firmware debug output - add resource and telemetry data uapi - preemption support imx: - add driver for HDMI TX Parallel audio interface ivpu: - add support for user-managed preemption buffer - add userptr support - update JSM firware API to 3.33.0 - add better alloc/free warnings - fix page fault in unbind all bos - rework bind/unbind of imported buffers - enable MCA ECC signalling - split fw runtime and global memory buffers - add fdinfo memory statistics tidss: - convert to drm logging - logging cleanup ast: - refactor generation init paths - add per chip generation detect_tx_chip - set quirks for each chip model atmel-hlcdc: - set LCDC_ATTRE register in plane disable - set correct values for plane scaler solomon: - use drm helper for get_modes and move_valid sitronix: - fix output position when clearing screens qaic: - support dma-buf exports - support new firmware's READ_DATA implementation - sahara AIC200 image table update - add sysfs support - add coredump support - add uevents support - PM support sun4i: - layer refactors to decouple plane from output - improve DE33 support vc4: - switch to generic CEC helpers komeda: - use drm_ logging functions vkms: - configfs support for display configuration vgem: - fix fence timer deadlock etnaviv: - add HWDB entry for GC8000 Nano Ultra VIP r6205" * tag 'drm-next-2025-12-03' of https://gitlab.freedesktop.org/drm/kernel: (1869 commits) Revert "drm/amd: Skip power ungate during suspend for VPE" drm/amdgpu: use common defines for HUB faults drm/amdgpu/gmc12: add amdgpu_vm_handle_fault() handling drm/amdgpu/gmc11: add amdgpu_vm_handle_fault() handling drm/amdgpu: use static ids for ACP platform devs drm/amdgpu/sdma6: Update SDMA 6.0.3 FW version to include UMQ protected-fence fix drm/amdgpu: Forward VMID reservation errors drm/amdgpu/gmc8: Delegate VM faults to soft IRQ handler ring drm/amdgpu/gmc7: Delegate VM faults to soft IRQ handler ring drm/amdgpu/gmc6: Delegate VM faults to soft IRQ handler ring drm/amdgpu/gmc6: Cache VM fault info drm/amdgpu/gmc6: Don't print MC client as it's unknown drm/amdgpu/cz_ih: Enable soft IRQ handler ring drm/amdgpu/tonga_ih: Enable soft IRQ handler ring drm/amdgpu/iceland_ih: Enable soft IRQ handler ring drm/amdgpu/cik_ih: Enable soft IRQ handler ring drm/amdgpu/si_ih: Enable soft IRQ handler ring drm/amd/display: fix typo in display_mode_core_structs.h drm/amd/display: fix Smart Power OLED not working after S4 drm/amd/display: Move RGB-type check for audio sync to DCE HW sequence ...
2025-12-03Merge tag 'kbuild-6.19-1' of ↵Linus Torvalds1-2/+6
git://git.kernel.org/pub/scm/linux/kernel/git/kbuild/linux Pull Kbuild updates from Nicolas Schier: - Enable -fms-extensions, allowing anonymous use of tagged struct or union in struct/union (tag kbuild-ms-extensions-6.19). An exemplary conversion patch is added here, too (btrfs). [ Editor's note: the core of this actually came in early through a shared branch and a few other trees - Linus ] - Introduce architecture-specific CC_CAN_LINK and flags for userprogs - Add new packaging target 'modules-cpio-pkg' for building a initramfs cpio w/ kmods - Handle included .c files in gen_compile_commands - Minor kbuild changes: - Use objtree for module signing key path, fixing oot kmod signing - Improve documentation of KBUILD_BUILD_TIMESTAMP - Reuse KBUILD_USERCFLAGS for UAPI, instead of defining twice - Rename scripts/Makefile.extrawarn to Makefile.warn - Drop obsolete types.h check from headers_check.pl - Remove outdated config leak ignore entries * tag 'kbuild-6.19-1' of git://git.kernel.org/pub/scm/linux/kernel/git/kbuild/linux: kbuild: add target to build a cpio containing modules initramfs: add gen_init_cpio to hostprogs unconditionally kbuild: allow architectures to override CC_CAN_LINK init: deduplicate cc-can-link.sh invocations kbuild: don't enable CC_CAN_LINK if the dummy program generates warnings scripts: headers_install.sh: Remove two outdated config leak ignore entries scripts/clang-tools: Handle included .c files in gen_compile_commands kbuild: uapi: Drop types.h check from headers_check.pl kbuild: Rename Makefile.extrawarn to Makefile.warn MAINTAINERS, .mailmap: Update mail address for Nicolas Schier kbuild: uapi: reuse KBUILD_USERCFLAGS kbuild: doc: improve KBUILD_BUILD_TIMESTAMP documentation kbuild: Use objtree for module signing key path btrfs: send: make use of -fms-extensions for defining struct fs_path
2025-12-02Merge tag 'core-rseq-2025-11-30' of ↵Linus Torvalds2-1/+30
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull rseq updates from Thomas Gleixner: "A large overhaul of the restartable sequences and CID management: The recent enablement of RSEQ in glibc resulted in regressions which are caused by the related overhead. It turned out that the decision to invoke the exit to user work was not really a decision. More or less each context switch caused that. There is a long list of small issues which sums up nicely and results in a 3-4% regression in I/O benchmarks. The other detail which caused issues due to extra work in context switch and task migration is the CID (memory context ID) management. It also requires to use a task work to consolidate the CID space, which is executed in the context of an arbitrary task and results in sporadic uncontrolled exit latencies. The rewrite addresses this by: - Removing deprecated and long unsupported functionality - Moving the related data into dedicated data structures which are optimized for fast path processing. - Caching values so actual decisions can be made - Replacing the current implementation with a optimized inlined variant. - Separating fast and slow path for architectures which use the generic entry code, so that only fault and error handling goes into the TIF_NOTIFY_RESUME handler. - Rewriting the CID management so that it becomes mostly invisible in the context switch path. That moves the work of switching modes into the fork/exit path, which is a reasonable tradeoff. That work is only required when a process creates more threads than the cpuset it is allowed to run on or when enough threads exit after that. An artificial thread pool benchmarks which triggers this did not degrade, it actually improved significantly. The main effect in migration heavy scenarios is that runqueue lock held time and therefore contention goes down significantly" * tag 'core-rseq-2025-11-30' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (54 commits) sched/mmcid: Switch over to the new mechanism sched/mmcid: Implement deferred mode change irqwork: Move data struct to a types header sched/mmcid: Provide CID ownership mode fixup functions sched/mmcid: Provide new scheduler CID mechanism sched/mmcid: Introduce per task/CPU ownership infrastructure sched/mmcid: Serialize sched_mm_cid_fork()/exit() with a mutex sched/mmcid: Provide precomputed maximal value sched/mmcid: Move initialization out of line signal: Move MMCID exit out of sighand lock sched/mmcid: Convert mm CID mask to a bitmap cpumask: Cache num_possible_cpus() sched/mmcid: Use cpumask_weighted_or() cpumask: Introduce cpumask_weighted_or() sched/mmcid: Prevent pointless work in mm_update_cpus_allowed() sched/mmcid: Move scheduler code out of global header sched: Fixup whitespace damage sched/mmcid: Cacheline align MM CID storage sched/mmcid: Use proper data structures sched/mmcid: Revert the complex CID management ...
2025-12-01Merge tag 'kernel-6.19-rc1.cred' of ↵Linus Torvalds1-0/+27
git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs Pull cred guard updates from Christian Brauner: "This contains substantial credential infrastructure improvements adding guard-based credential management that simplifies code and eliminates manual reference counting in many subsystems. Features: - Kernel Credential Guards Add with_kernel_creds() and scoped_with_kernel_creds() guards that allow using the kernel credentials without allocating and copying them. This was requested by Linus after seeing repeated prepare_kernel_creds() calls that duplicate the kernel credentials only to drop them again later. The new guards completely avoid the allocation and never expose the temporary variable to hold the kernel credentials anywhere in callers. - Generic Credential Guards Add scoped_with_creds() guards for the common override_creds() and revert_creds() pattern. This builds on earlier work that made override_creds()/revert_creds() completely reference count free. - Prepare Credential Guards Add prepare credential guards for the more complex pattern of preparing a new set of credentials and overriding the current credentials with them: - prepare_creds() - modify new creds - override_creds() - revert_creds() - put_cred() Cleanups: - Make init_cred static since it should not be directly accessed - Add kernel_cred() helper to properly access the kernel credentials - Fix scoped_class() macro that was introduced two cycles ago - coredump: split out do_coredump() from vfs_coredump() for cleaner credential handling - coredump: move revert_cred() before coredump_cleanup() - coredump: mark struct mm_struct as const - coredump: pass struct linux_binfmt as const - sev-dev: use guard for path" * tag 'kernel-6.19-rc1.cred' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: (36 commits) trace: use override credential guard trace: use prepare credential guard coredump: use override credential guard coredump: use prepare credential guard coredump: split out do_coredump() from vfs_coredump() coredump: mark struct mm_struct as const coredump: pass struct linux_binfmt as const coredump: move revert_cred() before coredump_cleanup() sev-dev: use override credential guards sev-dev: use prepare credential guard sev-dev: use guard for path cred: add prepare credential guard net/dns_resolver: use credential guards in dns_query() cgroup: use credential guards in cgroup_attach_permissions() act: use credential guards in acct_write_process() smb: use credential guards in cifs_get_spnego_key() nfs: use credential guards in nfs_idmap_get_key() nfs: use credential guards in nfs_local_call_write() nfs: use credential guards in nfs_local_call_read() erofs: use credential guards ...
2025-12-01Merge tag 'namespace-6.19-rc1' of ↵Linus Torvalds1-6/+1
git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs Pull namespace updates from Christian Brauner: "This contains substantial namespace infrastructure changes including a new system call, active reference counting, and extensive header cleanups. The branch depends on the shared kbuild branch for -fms-extensions support. Features: - listns() system call Add a new listns() system call that allows userspace to iterate through namespaces in the system. This provides a programmatic interface to discover and inspect namespaces, addressing longstanding limitations: Currently, there is no direct way for userspace to enumerate namespaces. Applications must resort to scanning /proc/*/ns/ across all processes, which is: - Inefficient - requires iterating over all processes - Incomplete - misses namespaces not attached to any running process but kept alive by file descriptors, bind mounts, or parent references - Permission-heavy - requires access to /proc for many processes - No ordering or ownership information - No filtering per namespace type The listns() system call solves these problems: ssize_t listns(const struct ns_id_req *req, u64 *ns_ids, size_t nr_ns_ids, unsigned int flags); struct ns_id_req { __u32 size; __u32 spare; __u64 ns_id; struct /* listns */ { __u32 ns_type; __u32 spare2; __u64 user_ns_id; }; }; Features include: - Pagination support for large namespace sets - Filtering by namespace type (MNT_NS, NET_NS, USER_NS, etc.) - Filtering by owning user namespace - Permission checks respecting namespace isolation - Active Reference Counting Introduce an active reference count that tracks namespace visibility to userspace. A namespace is visible in the following cases: - The namespace is in use by a task - The namespace is persisted through a VFS object (namespace file descriptor or bind-mount) - The namespace is a hierarchical type and is the parent of child namespaces The active reference count does not regulate lifetime (that's still done by the normal reference count) - it only regulates visibility to namespace file handles and listns(). This prevents resurrection of namespaces that are pinned only for internal kernel reasons (e.g., user namespaces held by file->f_cred, lazy TLB references on idle CPUs, etc.) which should not be accessible via (1)-(3). - Unified Namespace Tree Introduce a unified tree structure for all namespaces with: - Fixed IDs assigned to initial namespaces - Lookup based solely on inode number - Maintained list of owned namespaces per user namespace - Simplified rbtree comparison helpers Cleanups - Header Reorganization: - Move namespace types into separate header (ns_common_types.h) - Decouple nstree from ns_common header - Move nstree types into separate header - Switch to new ns_tree_{node,root} structures with helper functions - Use guards for ns_tree_lock - Initial Namespace Reference Count Optimization - Make all reference counts on initial namespaces a nop to avoid pointless cacheline ping-pong for namespaces that can never go away - Drop custom reference count initialization for initial namespaces - Add NS_COMMON_INIT() macro and use it for all namespaces - pid: rely on common reference count behavior - Miscellaneous Cleanups - Rename exit_task_namespaces() to exit_nsproxy_namespaces() - Rename is_initial_namespace() and make argument const - Use boolean to indicate anonymous mount namespace - Simplify owner list iteration in nstree - nsfs: raise SB_I_NODEV, SB_I_NOEXEC, and DCACHE_DONTCACHE explicitly - nsfs: use inode_just_drop() - pidfs: raise DCACHE_DONTCACHE explicitly - pidfs: simplify PIDFD_GET__NAMESPACE ioctls - libfs: allow to specify s_d_flags - cgroup: add cgroup namespace to tree after owner is set - nsproxy: fix free_nsproxy() and simplify create_new_namespaces() Fixes: - setns(pidfd, ...) race condition Fix a subtle race when using pidfds with setns(). When the target task exits after prepare_nsset() but before commit_nsset(), the namespace's active reference count might have been dropped. If setns() then installs the namespaces, it would bump the active reference count from zero without taking the required reference on the owner namespace, leading to underflow when later decremented. The fix resurrects the ownership chain if necessary - if the caller succeeded in grabbing passive references, the setns() should succeed even if the target task exits or gets reaped. - Return EFAULT on put_user() error instead of success - Make sure references are dropped outside of RCU lock (some namespaces like mount namespace sleep when putting the last reference) - Don't skip active reference count initialization for network namespace - Add asserts for active refcount underflow - Add asserts for initial namespace reference counts (both passive and active) - ipc: enable is_ns_init_id() assertions - Fix kernel-doc comments for internal nstree functions - Selftests - 15 active reference count tests - 9 listns() functionality tests - 7 listns() permission tests - 12 inactive namespace resurrection tests - 3 threaded active reference count tests - commit_creds() active reference tests - Pagination and stress tests - EFAULT handling test - nsid tests fixes" * tag 'namespace-6.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: (103 commits) pidfs: simplify PIDFD_GET_<type>_NAMESPACE ioctls nstree: fix kernel-doc comments for internal functions nsproxy: fix free_nsproxy() and simplify create_new_namespaces() selftests/namespaces: fix nsid tests ns: drop custom reference count initialization for initial namespaces pid: rely on common reference count behavior ns: add asserts for initial namespace active reference counts ns: add asserts for initial namespace reference counts ns: make all reference counts on initial namespace a nop ipc: enable is_ns_init_id() assertions fs: use boolean to indicate anonymous mount namespace ns: rename is_initial_namespace() ns: make is_initial_namespace() argument const nstree: use guards for ns_tree_lock nstree: simplify owner list iteration nstree: switch to new structures nstree: add helper to operate on struct ns_tree_{node,root} nstree: move nstree types into separate header nstree: decouple from ns_common header ns: move namespace types into separate header ...
2025-11-27calibrate: update header inclusionAndy Shevchenko1-3/+6
While cleaning up some headers, I got a build error on this file: init/calibrate.c:20:9: error: call to undeclared function 'kstrtoul'; ISO C99 and later do not support implicit function declarations [-Wimplicit-function-declaration] Update header inclusions to follow IWYU (Include What You Use) principle. Link: https://lkml.kernel.org/r/20251124230607.1445421-1-andriy.shevchenko@linux.intel.com Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-27init: replace simple_strtoul with kstrtoul to improve lpj_setupThorsten Blum1-2/+2
Replace simple_strtoul() with the recommended kstrtoul() for parsing the 'lpj=' boot parameter. Check the return value of kstrtoul() and reject invalid values. This adds error handling while preserving existing behavior for valid values, and removes use of the deprecated simple_strtoul() helper. Link: https://lkml.kernel.org/r/20251122114539.446937-2-thorsten.blum@linux.dev Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev> Cc: Christian Brauner <brauner@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-27liveupdate: kho: move to kernel/liveupdatePasha Tatashin1-0/+2
Move KHO to kernel/liveupdate/ in preparation of placing all Live Update core kernel related files to the same place. [pasha.tatashin@soleen.com: disable the menu when DEFERRED_STRUCT_PAGE_INIT] Link: https://lkml.kernel.org/r/CA+CK2bAvh9Oa2SLfsbJ8zztpEjrgr_hr-uGgF1coy8yoibT39A@mail.gmail.com Link: https://lkml.kernel.org/r/20251101142325.1326536-8-pasha.tatashin@soleen.com Signed-off-by: Pasha Tatashin <pasha.tatashin@soleen.com> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Reviewed-by: Mike Rapoport (Microsoft) <rppt@kernel.org> Cc: Alexander Graf <graf@amazon.com> Cc: Changyuan Lyu <changyuanl@google.com> Cc: Christian Brauner <brauner@kernel.org> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Masahiro Yamada <masahiroy@kernel.org> Cc: Miguel Ojeda <ojeda@kernel.org> Cc: Pratyush Yadav <pratyush@kernel.org> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Simon Horman <horms@kernel.org> Cc: Tejun Heo <tj@kernel.org> Cc: Zhu Yanjun <yanjun.zhu@linux.dev> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-20sched/mmcid: Use proper data structuresThomas Gleixner1-0/+3
Having a lot of CID functionality specific members in struct task_struct and struct mm_struct is not really making the code easier to read. Encapsulate the CID specific parts in data structures and keep them separate from the stuff they are embedded in. No functional change. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Link: https://patch.msgid.link/20251119172549.131573768@linutronix.de
2025-11-16convert ramfs and tmpfsAl Viro1-1/+1
Quite a bit is already done by infrastructure changes (simple_link(), simple_unlink()) - all that is left is replacing d_instantiate() + pinning dget() (in ->symlink() and ->mknod()) with d_make_persistent(), and, in case of shmem, using simple_unlink() and simple_link() in ->unlink() and ->link() resp., instead of open-coding those there. Since d_make_persistent() accepts (and hashes) unhashed ones, shmem situation gets simpler - we no longer care whether ->lookup() has hashed the sucker. With that done, we don't need kill_litter_super() for these filesystems anymore - by the umount time all remaining dentries will be marked persistent and kill_litter_super() will boil down to call of kill_anon_super(). The same goes for devtmpfs and rootfs - they are handled by ramfs or by shmem, depending upon config. NB: strictly speaking, both devtmpfs and rootfs ought to use ramfs_kill_sb() if they end up using ramfs; that's a separate story and the only impact of "just use kill_{litter,anon}_super()" is that we fail to free their sb->s_fs_info... on reboot. That's orthogonal to the changes in this series - kill_litter_super() is identical to kill_anon_super() for those at this point. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2025-11-14kbuild: allow architectures to override CC_CAN_LINKThomas Weißschuh1-0/+4
The generic test for CC_CAN_LINK assumes that all architectures use -m32 and -m64 to switch between 32-bit and 64-bit compilation. This is overly simplistic. Architectures may use other flags (-mabi, -m31, etc.) or may also require byte order handling (-mlittle-endian, -EL). Expressing all of the different possibilities will be very complicated and brittle. Instead allow architectures to supply their own logic which will be easy to understand and evolve. Both the boolean ARCH_HAS_CC_CAN_LINK and the string ARCH_USERFLAGS need to be implemented as kconfig does not allow the reuse of string options. Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de> Reviewed-by: Nicolas Schier <nsc@kernel.org> Reviewed-by: Nathan Chancellor <nathan@kernel.org> Link: https://patch.msgid.link/20251114-kbuild-userprogs-bits-v3-3-4dee0d74d439@linutronix.de Signed-off-by: Nicolas Schier <nsc@kernel.org>
2025-11-14init: deduplicate cc-can-link.sh invocationsThomas Weißschuh1-2/+2
The command to invoke scripts/cc-can-link.sh is very long and new usages are about to be added. Add a helper variable to make the code easier to read and maintain. Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de> Reviewed-by: Nicolas Schier <nsc@kernel.org> Reviewed-by: Nathan Chancellor <nathan@kernel.org> Link: https://patch.msgid.link/20251114-kbuild-userprogs-bits-v3-2-4dee0d74d439@linutronix.de Signed-off-by: Nicolas Schier <nsc@kernel.org>
2025-11-14rust: enable slice_flatten feature and provide it through an extension traitAlexandre Courbot1-0/+3
In Rust 1.80, the previously unstable `slice::flatten` family of methods have been stabilized and renamed to `slice::as_flattened`. This creates an issue as we want to use `as_flattened`, but need to support the MSRV (which at the moment is Rust 1.78) where it is named `flatten`. Solve this by enabling the `slice_flatten` feature, and providing an `as_flattened` implementation through an extension trait for compiler versions where it is not available. The trait is then exported from the prelude, making the `as_flattened` family of methods transparently available for all supported compiler versions. This extension trait can be removed once the MSRV passes 1.80. Suggested-by: Miguel Ojeda <ojeda@kernel.org> Link: https://lore.kernel.org/all/CANiq72kK4pG=O35NwxPNoTO17oRcg1yfGcvr3==Fi4edr+sfmw@mail.gmail.com/ Acked-by: Danilo Krummrich <dakr@kernel.org> Acked-by: Miguel Ojeda <ojeda@kernel.org> Reviewed-by: Alice Ryhl <aliceryhl@google.com> Signed-off-by: Alexandre Courbot <acourbot@nvidia.com> Message-ID: <20251110-gsp_boot-v9-8-8ae4058e3c0e@nvidia.com> Message-ID: <20251104-b4-as-flattened-v3-1-6cb9c26b45cd@nvidia.com>
2025-11-12init/main.c: wrap long kernel cmdline when printing to logsDouglas Anderson2-1/+114
The kernel cmdline length is allowed to be longer than what printk can handle. When this happens the cmdline that's printed to the kernel ring buffer at bootup is cutoff and some kernel cmdline options are "hidden" from the logs. This undercuts the usefulness of the log message. Specifically, grepping for COMMAND_LINE_SIZE shows that 2048 is common and some architectures even define it as 4096. s390 allows a CONFIG-based maximum up to 1MB (though it's not expected that anyone will go over the default max of 4096 [1]). The maximum message pr_notice() seems to be able to handle (based on experiment) is 1021 characters. This appears to be based on the current value of PRINTKRB_RECORD_MAX as 1024 and the fact that pr_notice() spends 2 characters on the loglevel prefix and we have a '\n' at the end. While it would be possible to increase the limits of printk() (and therefore pr_notice()) somewhat, it doesn't appear possible to increase it enough to fully include a 2048-character cmdline without breaking userspace. Specifically on at least two tested userspaces (ChromeOS plus the Debian-based distro I'm typing this message on) the `dmesg` tool reads lines from `/dev/kmsg` in 2047-byte chunks. As per `Documentation/ABI/testing/dev-kmsg`: Every read() from the opened device node receives one record of the kernel's printk buffer. ... Messages in the record ring buffer get overwritten as whole, there are never partial messages received by read(). We simply can't fit a 2048-byte cmdline plus the "Kernel command line:" prefix plus info about time/log_level/etc in a 2047-byte read. The above means that if we want to avoid the truncation we need to do some type of wrapping of the cmdline when printing. Add wrapping to the printout of the kernel command line. By default, the wrapping is set to 1021 characters to avoid breaking anyone, but allow wrapping to be set lower by a Kconfig knob "CONFIG_CMDLINE_LOG_WRAP_IDEAL_LEN". Any tools that are correctly parsing the cmdline today (because it is less than 1021 characters) will see no difference in their behavior. The format of wrapped output is designed to be matched by anyone using "grep" to search for the cmdline and also to be easy for tools to handle. Anyone who is sure their tools (if any) handle the wrapped format can choose a lower wrapping value and have prettier output. Setting CONFIG_CMDLINE_LOG_WRAP_IDEAL_LEN to 0 fully disables the wrapping logic. This means that long command lines will be truncated again, but this config could be set if command lines are expected to be long and userspace is known not to handle parsing logs with the wrapping. Wrapping is based on spaces, ignoring quotes. All lines are prefixed with "Kernel command line: " and lines that are not the last line have a " \" suffix added to them. The prefix and suffix count towards the line length for wrapping purposes. The ideal length will be exceeded if no appropriate place to wrap is found. The wrapping function added here is fairly generic and could be made a library function (somewhat like print_hex_dump()) if it's needed elsewhere in the kernel. However, having printk() directly incorporate this wrapping would be unlikely to be a good idea since it would break printouts into more than one record without any obvious common line prefix to tie lines together. It would also be extra overhead when, in general, kernel log message should simply be kept smaller than 1021 bytes. For some discussion on this topic, see responses to the v1 posting of this patch [2]. [akpm@linux-foundation.org: make print_kernel_cmdline __init] [dianders@chromium.org: v4] Link: https://lkml.kernel.org/r/20251027082204.v4.1.I095f1e2c6c27f9f4de0b4841f725f356c643a13f@changeid Link: https://lkml.kernel.org/r/20251023113257.v3.1.I095f1e2c6c27f9f4de0b4841f725f356c643a13f@changeid Link: https://lore.kernel.org/r/20251021131633.26700Dd6-hca@linux.ibm.com [1] Link: https://lore.kernel.org/r/CAD=FV=VNyt1zG_8pS64wgV8VkZWiWJymnZ-XCfkrfaAhhFSKcA@mail.gmail.com [2] Signed-off-by: Douglas Anderson <dianders@chromium.org> Tested-by: Paul E. McKenney <paulmck@kernel.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Andrew Chant <achant@google.com> Cc: Brian Gerst <brgerst@gmail.com> Cc: Christian Brauner <brauner@kernel.org> Cc: Francesco Valla <francesco@valla.it> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: guoweikang <guoweikang.kernel@gmail.com> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Huacai Chen <chenhuacai@kernel.org> Cc: Ingo Molnar <mingo@kernel.org> Cc: Jan Hendrik Farr <kernel@jfarr.cc> Cc: Jeff Xu <jeffxu@chromium.org> Cc: Kees Cook <kees@kernel.org> Cc: Masahiro Yamada <masahiroy@kernel.org> Cc: Michal Koutný <mkoutny@suse.com> Cc: Miguel Ojeda <ojeda@kernel.org> Cc: Mike Rapoport <rppt@kernel.org> Cc: Nathan Chancellor <nathan@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Shakeel Butt <shakeel.butt@linux.dev> Cc: Sven Schnelle <svens@linux.ibm.com> Cc: Tejun Heo <tj@kernel.org> Cc: Thomas Gleinxer <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-11ns: drop custom reference count initialization for initial namespacesChristian Brauner1-1/+1
Initial namespaces don't modify their reference count anymore. They remain fixed at one so drop the custom refcount initializations. Link: https://patch.msgid.link/20251110-work-namespace-nstree-fixes-v1-16-e8a9264e0fb9@kernel.org Signed-off-by: Christian Brauner <brauner@kernel.org>
2025-11-05init: Replace simple_strtoul() with kstrtouint() in root_delay_setup()Kaushlendra Kumar1-1/+2
Replace deprecated simple_strtoul() with kstrtouint() for better error handling and input validation. Return 0 on parsing failure to indicate invalid parameter, maintaining existing behavior for valid inputs. The simple_strtoul() function is deprecated in favor of kstrtoint() family functions which provide better error handling and are recommended for new code and replacements. Signed-off-by: Kaushlendra Kumar <kaushlendra.kumar@intel.com> Link: https://patch.msgid.link/20251103080627.1844645-1-kaushlendra.kumar@intel.com Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Christian Brauner <brauner@kernel.org>
2025-11-04cred: make init_cred staticChristian Brauner1-0/+27
There's zero need to expose struct init_cred. The very few places that need access can just go through init_task which is already exported. Link: https://patch.msgid.link/20251103-work-creds-init_cred-v1-3-cb3ec8711a6a@kernel.org Reviewed-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Christian Brauner <brauner@kernel.org>
2025-11-04rseq: Switch to fast path processing on exit to userThomas Gleixner1-1/+1
Now that all bits and pieces are in place, hook the RSEQ handling fast path function into exit_to_user_mode_prepare() after the TIF work bits have been handled. If case of fast path failure, TIF_NOTIFY_RESUME has been raised and the caller needs to take another turn through the TIF handling slow path. This only works for architectures which use the generic entry code. Architectures who still have their own incomplete hacks are not supported and won't be. This results in the following improvements: Kernel build Before After Reduction exit to user 80692981 80514451 signal checks: 32581 121 99% slowpath runs: 1201408 1.49% 198 0.00% 100% fastpath runs: 675941 0.84% N/A id updates: 1233989 1.53% 50541 0.06% 96% cs checks: 1125366 1.39% 0 0.00% 100% cs cleared: 1125366 100% 0 100% cs fixup: 0 0% 0 RSEQ selftests Before After Reduction exit to user: 386281778 387373750 signal checks: 35661203 0 100% slowpath runs: 140542396 36.38% 100 0.00% 100% fastpath runs: 9509789 2.51% N/A id updates: 176203599 45.62% 9087994 2.35% 95% cs checks: 175587856 45.46% 4728394 1.22% 98% cs cleared: 172359544 98.16% 1319307 27.90% 99% cs fixup: 3228312 1.84% 3409087 72.10% The 'cs cleared' and 'cs fixup' percentages are not relative to the exit to user invocations, they are relative to the actual 'cs check' invocations. While some of this could have been avoided in the original code, like the obvious clearing of CS when it's already clear, the main problem of going through TIF_NOTIFY_RESUME cannot be solved. In some workloads the RSEQ notify handler is invoked more than once before going out to user space. Doing this once when everything has stabilized is the only solution to avoid this. The initial attempt to completely decouple it from the TIF work turned out to be suboptimal for workloads, which do a lot of quick and short system calls. Even if the fast path decision is only 4 instructions (including a conditional branch), this adds up quickly and becomes measurable when the rate for actually having to handle rseq is in the low single digit percentage range of user/kernel transitions. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Reviewed-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Link: https://patch.msgid.link/20251027084307.701201365@linutronix.de
2025-11-04rseq: Provide static branch for runtime debuggingThomas Gleixner1-0/+14
Config based debug is rarely turned on and is not available easily when things go wrong. Provide a static branch to allow permanent integration of debug mechanisms along with the usual toggles in Kconfig, command line and debugfs. Requested-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Reviewed-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Link: https://patch.msgid.link/20251027084307.089270547@linutronix.de
2025-11-04rseq: Expose lightweight statistics in debugfsThomas Gleixner1-0/+12
Analyzing the call frequency without actually using tracing is helpful for analysis of this infrastructure. The overhead is minimal as it just increments a per CPU counter associated to each operation. The debugfs readout provides a racy sum of all counters. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Reviewed-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Link: https://patch.msgid.link/20251027084307.027916598@linutronix.de
2025-11-03ns: use NS_COMMON_INIT() for all namespacesChristian Brauner1-6/+1
Now that we have a common initializer use it for all static namespaces. Signed-off-by: Christian Brauner <brauner@kernel.org>
2025-10-31initrd: Replace simple_strtol with kstrtoint to improve ramdisk_start_setupThorsten Blum1-2/+1
Replace simple_strtol() with the recommended kstrtoint() for parsing the 'ramdisk_start=' boot parameter. Unlike simple_strtol(), which returns a a long, kstrtoint() converts the string directly to an integer and avoids implicit casting. Check the return value of kstrtoint() and reject invalid values. This adds error handling while preserving existing behavior for valid values, and removes use of the deprecated simple_strtol() helper. Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev> Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Christian Brauner <brauner@kernel.org>
2025-10-04Merge 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