kernel/git/next/linux-next.git/lib, branch master

Merge branch 'non-rcu/next' of https://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu.git

2026-08-28T13:12:27+00:00

# Conflicts: # kernel/smp.c

lib/group_cpus: snapshot cluster masks to keep grouping hotplug invariant

2026-08-28T05:50:07+00:00

group_cpus_evenly() builds the managed-IRQ affinity spread used by multi-queue devices such as NVMe. That spread is meant to be a property of the static CPU topology: it walks cpu_present_mask and then cpu_possible_mask so every hardware queue owns a fixed set of CPUs, including CPUs that are offline at the time. A driver depends on that partition staying stable across re-computation - the CPUs a queue is given at probe must still describe the same queue after the device is later reset and its affinity recomputed. On an AMD system that stability breaks across an s2idle cycle. With CPUs 3-11 offlined and only CPUs 0-2 left online, the machine is suspended to s2idle and resumed. The NVMe controller uses the simple-suspend quirk, so resume fully re-initialises it and recomputes the affinity spread. The system then hangs for roughly two minutes and stays sluggish afterwards, the controller only making progress through its command-timeout poll: nvme nvme0: I/O tag 898 (3382) QID 9 timeout, completion polled nvme nvme0: I/O tag 398 (618e) QID 11 timeout, completion polled QID 9 and QID 11 are the queues whose CPUs were offline when the spread was recomputed. "completion polled" means the commands did finish in hardware, but their interrupts were never delivered to a CPU that was watching the queue, so nothing reaped them until the timeout fired. It happens because commit 89802ca36c96 ("lib/group_cpus: make group CPU cluster aware") derives the cluster groups from topology_cluster_cpumask(), which lists only the cluster siblings that are online when it is called. The resulting partition therefore depends on the transient online mask rather than on the topology alone. Recomputed on resume while the non-boot CPUs are still offline, it no longer matches the boot-time partition, and a queue is left with an affinity that does not cover the CPU it is meant to serve once that CPU comes back online. The dependence is on the online mask, not on any AMD-specific behaviour, so the same stall is reproducible on Intel platforms as well. Make the cluster grouping depend on the complete cluster topology rather than on whichever CPUs happen to be online. Snapshot the cluster masks once while every present CPU is online and reuse that view for every later spread. Every spread then groups from the same masks, so the partition computed when the controller is reset matches the one computed at probe and each queue's IRQ still covers the CPUs it serves. If the snapshot was never taken, the cluster path is skipped and the plain present/possible spread is used. Link: https://lore.kernel.org/20260826171537.4167367-1-Vishal.Badole@amd.com Fixes: 89802ca36c96 ("lib/group_cpus: make group CPU cluster aware") Signed-off-by: Vishal Badole Cc: "Borislav Petkov (AMD)" Cc: Radu Rendec Cc: Thomas Gleixner Cc: Tim Chen Cc: Wangyang Guo Cc: Tianyou Li Cc: Dan Liang Cc: Signed-off-by: Andrew Morton

klist: avoid accesses after waking klist_remove()

2026-08-28T05:50:06+00:00

klist_remove() waits until a node is unreferenced so that its caller can free the containing object. klist_release() currently publishes waiter->woken and wakes the waiter before its final accesses to the waiter and node. klist_remove() can then return, allowing its stack waiter and the containing object to be freed or reused while klist_release() is still running. In particular, bus_remove_driver() can free drv->p while __device_attach() walks the same bus klist with bus_for_each_drv(). On an arm64 Cortex-A72 system, an unpatched 7.2.0-rc3 kernel with CONFIG_PREEMPT_RT=y and CONFIG_KASAN=y reproduced the bug through the in-tree I2C/at24 path. KASAN reported a use-after-free in klist_dec_and_del() reached from klist_next()/bus_for_each_drv() while at24 was being unregistered. Clear n_klist and take a task reference before publishing woken. Use release/acquire accesses for that publication and wake the referenced task. The task reference keeps the waiter task alive if it returns and exits before wake_up_process(). Link: https://lore.kernel.org/20260827041708.31682-1-kmehltretter@gmail.com Fixes: 8b0c250be489 ("[PATCH] add klist_node_attached() to determine if a node is on a list or not.") Fixes: 210272a28465 ("driver core: Remove completion from struct klist_node") Assisted-by: LLM Signed-off-by: Karl Mehltretter Cc: Danilo Krummrich Cc: Greg Kroah-Hartman Cc: Matthew Wilcox (Oracle) Cc: "Rafael J. Wysocki" Cc: Signed-off-by: Andrew Morton

raid/kunit: enable RAID6 PQ and XOR benchmarks if KUNIT_ALL_TESTS=m

2026-08-28T05:50:06+00:00

Enabling the (possibly long-running benchmarks) by default may cause a big delay in boot time in case of built-in tests. However, they can still safely be enabled by default if all tests are modular, as they would only run when requested explicitly by the system administrator. Link: https://lore.kernel.org/64c6e0191bd8ccef0074ffbb09bd0584680d710b.1787584360.git.geert@linux-m68k.org Signed-off-by: Geert Uytterhoeven Reviewed-by: Christoph Hellwig Acked-by: Ard Biesheuvel Cc: Eric Biggers Signed-off-by: Andrew Morton

fault-inject: fix dentry leak

2026-08-28T05:50:04+00:00

fault_create_debugfs_attr() has always taken an extra dentry reference on the created directory (attr->dname = dget(dir)) so that fail_dump() could print the name via %pd from any context. Nothing anywhere in the tree ever calls dput() on attr->dname. For callers with a matching teardown, that unmatched reference causes one dentry plus its attached inode to leak per fault_create_debugfs_attr / debugfs_remove_recursive cycle. simple_recursive_removal() drops debugfs's own +1 ref on the child dentry, but the dget()'d ref keeps its refcount at 1: the dentry ends up unhashed but pinned, and its inode is never freed. Boot-once callers (mm/failslab, block/blk-core, etc.) leak exactly once at init and never destroy the tree, so the impact there is bounded. But per-lifecycle callers (drivers/nvme, drivers/infiniband/hw/hfi1, drivers/mmc, drivers/iommu/iommufd, drivers/media, drivers/misc, drivers/gpu/drm/msm, drivers/crypto, net/sunrpc) leak on every create/destroy cycle. We observed this in production: an NVMe/RDMA host repeatedly reconnecting to a target that rejected the CRTO Property Get went through ~50 nvme controller create/destroy cycles per second, and dentry and inode_cache grew by ~13k pinned objects per 240 s -- unrecoverable through drop_caches. Byte math matched a per-cycle 1-dentry / 1-inode leak from the "fault_inject" directory dentry. Fix this by not holding any external reference in fault_attr. Embed the directory name as a fixed-size char array (FAULT_ATTR_DNAME_LEN, 64 bytes) inside struct fault_attr, copied by strscpy() at fault_create_debugfs_attr() time. fail_dump() prints it via %s. Advantages of an embedded array over kstrdup() + kfree() paired with a new destroy API: - Zero API footprint. No new export and no caller changes required: callers already own their fault_attr's memory and free it when they are done, and now that suffices. - No allocation on the create path. - fault_create_debugfs_attr() cannot fail from the name-copy step. - No lifetime coupling between attr->dname and debugfs; the string is valid for exactly as long as the containing struct. The 64-byte length accommodates every in-tree caller with generous headroom (the longest current name is "fail_dma_array_full", 19 chars). The user-visible fail_dump() format changes from "name %pd" to "name %s", but the printed content is identical -- %pd on the created directory renders the same string that was passed in as @name. drivers/infiniband/hw/hfi1/fault.c drops a now-invalid "attr.dname = NULL" statement; the surrounding kzalloc() already zero-initialises the array. Link: https://lore.kernel.org/20260821181527.3271414-1-mliang@purestorage.com Fixes: 6adc4a22f20b ("fault-inject: add ratelimit option") Signed-off-by: Michael Liang Reviewed-by: Andrew Morton Cc: Akinbou Mita Cc: Dennis Dalessandro Cc: Jason Gunthorpe Cc: Leon Romanovsky Cc: Vlastimil Babka Cc: Signed-off-by: Andrew Morton

Revert "once: don't use a work queue to reset sleepable static key"

2026-08-27T20:07:49+00:00

This reverts commit e8eef69a99f185e75909adb24ab93d706e07bf27. While DO_ONCE_SLEEPABLE() is used from sleepable/process context, callers may still be holding arbitrary subsystem locks. For instance, __inet_hash_connect() uses get_random_sleepable_once() which invokes DO_ONCE_SLEEPABLE() while holding the socket lock (sk_lock): lock_sock(sk) __inet_hash_connect() get_random_sleepable_once() DO_ONCE_SLEEPABLE() __do_once_sleepable_done() static_branch_disable() static_key_disable() cpus_read_lock() Calling static_branch_disable() directly from __do_once_sleepable_done() causes static_key_disable() to synchronously acquire cpus_read_lock() (cpu_hotplug_lock) and jump_label_mutex inside the caller's lock context. This introduces an unwanted lockdep dependency: sk_lock -> cpu_hotplug_lock Because cpu_hotplug_lock depends on fs_reclaim (via workqueue CPU bringup allocating memory with GFP_KERNEL), and storage/block layers (such as NVMe-TCP) acquire sk_lock during I/O dispatch, lockdep reports circular locking dependencies: set->srcu -> sk_lock -> cpu_hotplug_lock -> fs_reclaim -> q_usage_counter -> elevator_lock -> set->srcu This false positive previously prompted commit 19bdb70c77d3 ("nvme-tcp: lockdep: use dynamic lockdep keys per socket instance") to work around the warning using per-socket dynamic keys in NVMe-TCP. That in turn broke asynchronous socket teardown and caused syzbot warnings in tcp_tsq_handler(). Restoring once_disable_jump() in __do_once_sleepable_done() ensures that static_branch_disable() is executed asynchronously from a system workqueue without holding the caller's locks. Link: https://lore.kernel.org/20260825142515.1965654-1-edumazet@google.com Fixes: e8eef69a99f1 ("once: don't use a work queue to reset sleepable static key") Signed-off-by: Eric Dumazet Closes: https://lore.kernel.org/lkml/ao0mwtt8ePAINFni@shinhome/ Reported-by: Shin'ichiro Kawasaki Cc: Tony Luck Cc: Reinette Chatre Cc: Keith Busch Cc: Nilay Shroff Cc: Signed-off-by: Andrew Morton

Merge tag 'mm-stable-2026-08-26-15-22' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

2026-08-27T16:17:06+00:00

Pull more MM updates from Andrew Morton: - "mm/rmap: index MAP_PRIVATE file-backed folios by anonymous pgoff" (Lorenzo Stoakes) Index MAP_PRIVATE file-backed folios by their anonymous page offset to resolve confusion around reverse mapping for zeroed and CoW'd file-backed memory. Use this new VMA anonymous page offset tracking to eliminate index conflicts and lay the foundation for scalable CoW performance improvements. - "promote mapped executable folios after first usage for MGLRU" (Baolin Wang) Make MGLRU's protection of mapped executable file folios more reliable. Follow the classical LRU's logic, promoting mapped executable file folios after their first usage to give executable code a better chance to stay in memory and improve workload performance. - "mm: vmscan: fix node reclaim ignoring swappiness parameter" (Ridong Chen) Fix per-node proactive reclaim interface's ignoring the swappiness parameter when CONFIG_MEMCG is disabled by consolidating sc_swappiness() into a single function that checks proactive_swappiness regardless of kernel configuration. - "mm/vmscan: reduce lru_lock contention via vmstat-derived scan-balance cost" (Usama Arif) Reduce lru_lock contention in the reclaim path by deriving scan-balance costs from vmstat counters rather than lock-acquired producer updates. Read and decay these cost signals on the reclaim side under a dedicated per-lruvec lock, reducing total LRU lock wait time by over 60% without impacting scan throughput. - "zram: fix zram issues reported by sashiko" (Sergey Senozhatsky) Fix two low-risk zram bugs which Sashiko spotted in drive-by review. - "Honor XA_FLAGS_ACCOUNT in xas_split_alloc() and charge to folio's memcg" (Zi Yan) Fix xas_split_alloc() by enabling target folio memcg charging during splits and adding the missing __GFP_ACCOUNT flag for proper XArray node memory accounting. - "selftests/mm: use pattern matching in .gitignore" (Pratyush Mallick) Replace hardcoded binary names in selftests/mm/.gitignore with a generic pattern-matching rule to automatically ignore generated test files and avoid manual updates when adding new tests. - "mm/page_ext: remove pgdat_page_ext_init()" (Sang-Heon Jeon) Make the incompatibility between FLATMEM and NUMA explicit in mm/Kconfig and remove the unused pgdat_page_ext_init() function. - "zram: fix zstd error paths and add parameter validation" (Haoqin Huang) Clean up zram compression backends by removing redundant error cleanup, adding parameter and dictionary validation, auto-prefixing algorithm error logs, and resetting parameters prior to reinitialization. - "zram: fix stale scan bounds after reinitialization" (Longlong Xia) Prevent out-of-bounds slot accesses during concurrent zram resets by moving table scan bound calculations under dev_lock in writeback_store() and read_block_state(). - "add anon mTHP collapse test cases" (Baolin Wang) Extend selftests helper functions to support arbitrary page orders and add new test cases and options for mTHP collapse in khugepaged. - "selftests/mm: Handle unsupported and transient test conditions" (Muhammad Usama Anjum) Update MM selftests to report a SKIP status instead of a failure when required kernel or filesystem features are unsupported, while adding retry logic for transient page migration errors. - "mm/zswap: Fixes and improves the zswap shrink" (Hao Jia) Fix the missing zswap global shrinker when CONFIG_MEMCG is disabled and extend shrink_memcg() to support batch writeback for improved writeback efficiency. - "alloc_tag: introduce IOCTL-based filtering for MAP" (Suren Baghdasaryan) Introduce an IOCTL-based binary interface for memory allocation profiling that enables kernel-side filtering before per-CPU counter aggregation. This eliminates the text-parsing overhead of /proc/allocinfo and provides up to a 20x speedup by transferring only filtered allocation data to userspace. - "better block swap batching and a different take on swap_ops v5" (Christoph Hellwig) Refactor block swap I/O to use swap_iocb for batching instead of single-bio requests and rebase the swap_ops interface, achieving faster swap throughput during kernel builds. - "mm: kmemleak: reduce transient false positives by confirming leaks" (Catalin Marinas) Reduce false-positive kmemleak reports by combining two kmemleak enhancements that add a second confirmation scan and a configurable minimum unreferenced scan count module parameter. - "mm: kmemleak: default min_unref_scans to 2 for verbose kernels" (Breno Leitao) Auto-scanning kernels can generate false-positive memory leak reports on single scans, so this patch defaults min_unref_scans to 2 when CONFIG_DEBUG_KMEMLEAK_VERBOSE is enabled to require a second confirming scan. - "swap_ops updates" (Christoph Hellwig) Batching I/O for synchronous swap devices causes performance regressions and filesystem-based swap suffers from double-indirection overhead. This series resolves both issues by reintroducing per-folio writes for synchronous swap and allowing filesystems to directly export their own swap_ops. - "mm/khugepaged: several cleanups" (Nico Pache) khugepaged accumulated redundant state-checking patterns and outdated comments following mTHP integration. Introduce dedicated helpers for PTE validation and event counting while refreshing the internal documentation. - "maple_tree: lock checking and clean ups" (Liam Howlett) Syzbot reports incorrectly blame memory management exit paths for locking bugs, maple tree erase operations risk allocation failures without gfp flags and internal documentation lacks clarity. Improve lock error detection, update docs, fix race and allocation edge cases and optimize erase allocations using a fallback to GFP_KERNEL | GFP_NOFAIL. * tag 'mm-stable-2026-08-26-15-22' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (172 commits) selftests/proc: make proc-maps-race work with READ_IMPLIES_EXEC memcg: move LRU size accounting on reparenting instead of copying it mm/vmscan: fix comment logic in balance_pgdat maple_tree: add helper mas_make_walkable() maple_tree: avoid extra gap calculation maple_tree: fix argument name in header maple_tree: change two GFP flags in tests maple_tree: document erase and allocations better maple_tree: avoid mas_erase() and mtree_erase() failures maple_tree: document that erase may use GFP_KERNEL for allocations maple_tree: catch race in mas_alloc_cyclic() maple_tree: add bulk parent set helper maple_tree: micro optimisation of mas_wr_store_type() maple_tree: optimise mas_wr_node_store() when not in rcu mode maple_tree: use prefetched value in mas_wr_store_type() maple_tree: clarify comments on mas_nomem() maple_tree: drop MAPLE_ALLOC_SLOTS maple_tree: drop dead code from mas_extend_spanning_null() maple_tree: documentation fix maple_tree: add write lock checking with lockdep sequence numbers ...

Merge tag 'char-misc-7.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc

2026-08-25T16:38:50+00:00

Pull char/misc/IIO/etc driver updates from Greg KH: "Here is the big set of char, misc, iio, counter, fpga, and other small driver subsystems for 7.3-rc1. Overall, due to some driver removals we only added a bit more code than removed, which was a nice change. Highlights in this merge request are: - Loads of IIO driver updates and additions - binder driver updates (more on that below...) - Removal of the SGI XP and GRU drivers as they are not used anymore and turn out to be pretty insecure overall - Removal of the obsolete ibmasm driver as it's not being used anymore - Coresight driver updates and additions - Mei driver udpates - Counter driver updates - FPGA driver updates - ICC driver updates - lots and lots of other tiny driver updates to resolve reported issues All of these have been in linux-next for a while" * tag 'char-misc-7.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: (513 commits) iio: chemical: atlas-sensor: use iio_trigger_poll_nested() to fix remove UAF iio: adc: pac1921: fix wrong channel used in trigger handler read iio: light: gp2ap002: re-enable irq if runtime suspend fails iio: light: gp2ap002: Fix unbalanced runtime PM on repeated event writes iio: light: apds9306: fix PM reference leak in apds9306_read_data() iio: gyro: mpu3050: fix sign of raw angular velocity readings iio: srf04: fix pm_runtime handling on probe error path iio: adc: ad4080: configure backend data size iio: adc: adi-axi-adc: add data size support for AD408X backend iio: chemical: atlas-sensor: fix PM reference leak in buffer postenable iio: dac: ad5446: fix OF module device table iio: light: opt4001: Fix reversed GENMASK() arguments in fault count mask iio: light: opt4001: Reject integration times with a non-zero seconds part iio: light: opt4001: Fix incompatible pointer type passed to div_u64_rem() iio: light: opt4001: Fix power down clearing bits of the wrong register iio: light: opt4060: Fix incorrect register name in threshold read error message iio: light: opt4060: Fix pointer type passed to div_u64_rem() iio: light: opt4060: Reject integration times with a non-zero seconds part iio: light: ltrf216a: fix runtime PM reference leak in error path iio: pressure: dps310: fix NULL pointer dereference on ACPI probe ...

Merge tag 'bootconfig-v7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace

2026-08-25T15:59:09+00:00

Pull bootconfig updates from Masami Hiramatsu: - Support build-time command line building for embedded bootconfig - Fix xbc_snprint_cmdline() to render descendant keys when the root has both a value and subkeys, and treats empty subtrees correctly. - Add build-time pipeline using tools/bootconfig -C to render the embedded bootconfig "kernel" subtree into .init.rodata as a cmdline string. - Clean build-time tools/bootconfig from make clean - Add helper to prepend embedded bootconfig cmdline into boot_command_line early before parse_early_param() - Wire early prepend helper in x86 setup_arch() so early_param handlers see values from the embedded bootconfig (currently x86 only) - Avoid duplicating "kernel" keys in setup_boot_config() - Refactor setup_boot_config() to share bootconfig_cmdline_requested() - Document CONFIG_CMDLINE_FROM_BOOTCONFIG usage, requirements, and precedence * tag 'bootconfig-v7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: init/main.c: use bootconfig_cmdline_requested() for the runtime opt-in bootconfig: skip runtime kernel.* render once prepended early x86/setup: prepend embedded bootconfig cmdline before parse_early_param Documentation: bootconfig: document build-time cmdline rendering bootconfig: add xbc_prepend_embedded_cmdline() helper bootconfig: clean build-time tools/bootconfig from make clean bootconfig: render embedded bootconfig as a kernel cmdline at build time bootconfig: render descendant keys when xbc_snprint_cmdline() root has a value

maple_tree: add helper mas_make_walkable()

2026-08-25T01:43:32+00:00

A check in mas_walk() was incorrect and caused inefficient use of the maple state. The same issue existed in mas_erase(), but was left unfixed. Making a helper function is the obvious answer. Link: https://lore.kernel.org/20260821192627.4085470-20-liam@infradead.org Signed-off-by: Liam R. Howlett (Oracle) Cc: Boqun Feng Cc: Breno Leitao Cc: Chris Mason Cc: Chuck Lever Cc: Ingo Molnar Cc: Jason Gunthorpe Cc: Joe Perches Cc: Peter Zijlstra Cc: Rik van Riel Cc: Waiman Long Cc: Will Deacon Signed-off-by: Andrew Morton