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2026-09-26bitmap: bitmap_parselist(): don't wrap around on a huge group sizeShashank Mohan Jain
In the "range:used/group" form bitmap_set_region() walks the range with for (start = r->start; start <= r->end; start += r->group_len) where all values are unsigned int. bitmap_getnum() accepts any group size up to UINT_MAX, and bitmap_check_region() only requires it to be non-zero and at least the used size. If start + group_len exceeds UINT_MAX, start wraps around to a small value that is still <= end, and bits below the start of the range get set: "1-1:1/4294967295" -> bits 0,1 (expected bit 1) "15-15:1/4294967281" -> bits 0,15 (expected bit 15) The loop still terminates, because start keeps decreasing until it wraps past zero again, but the resulting mask contains bits outside the requested range. This needs a group size within 'start' of UINT_MAX, so it is unlikely to be hit by accident; all bits set stay below the end of the range, so there is no out-of-bounds write. A group larger than the range simply means that the range contains a single group, so stop the walk when the next group would start beyond UINT_MAX. Fixes: 0a5ce0831d04 ("lib/bitmap.c: make bitmap_parselist() thread-safe and much faster") Assisted-by: LLM Signed-off-by: Shashank Mohan Jain <jain.sm@gmail.com> Signed-off-by: Yury Norov <ynorov@nvidia.com>
2026-09-26bitmap: test bitmap_parselist() with text after the group sizeShashank Mohan Jain
Add bitmap_parselist() cases where 'N' or 'all' directly follows the group size of a "range:used/group" region. These were accepted before "bitmap: bitmap_parselist(): reject trailing characters after group size" and must return -EINVAL. Assisted-by: LLM Signed-off-by: Shashank Mohan Jain <jain.sm@gmail.com> Signed-off-by: Yury Norov <ynorov@nvidia.com>
2026-09-26bitmap: bitmap_parselist(): reject trailing characters after group sizeShashank Mohan Jain
bitmap_parse_region() checks that every region ends at a separator (',', whitespace, '\n' or '\0'), except in the "range:used/group" form: after parsing the group size it returns the pointer to the following character without looking at it. The caller then starts a new region at that character. Before 'N' and 'all' were accepted as region starts this happened to be harmless, because any other character would fail to parse as a new region. Now text directly following the group size is silently parsed as another region: "0-7:1/2N" -> bits 0,2,4,6,7 (nbits = 8), returns 0 "0-7:1/2all" -> all bits set, returns 0 while "0-7N", "5N" or "0-7:1/2x" are correctly rejected with -EINVAL. bitmap_parselist() is documented to return -EINVAL for an invalid character. It parses cpu lists from sysfs, cgroup cpuset files and boot parameters such as isolcpus= and nohz_full=, so a typo there is accepted and yields a different mask than intended. Check for the end of the region after the group size as well, like the other forms do. Fixes: 2c4885d24e64 ("lib: bitmap: support "N" as an alias for size of bitmap") Assisted-by: LLM Signed-off-by: Shashank Mohan Jain <jain.sm@gmail.com> Signed-off-by: Yury Norov <ynorov@nvidia.com>
2026-09-26bitmap: test bitmap_parse() with an illegal character before 8 hex digitsShashank Mohan Jain
Add bitmap_parse() cases where an illegal character directly precedes a chunk of eight hex digits. These were accepted before the previous patch and must return -EINVAL. Assisted-by: LLM Signed-off-by: Shashank Mohan Jain <jain.sm@gmail.com> Signed-off-by: Yury Norov <ynorov@nvidia.com>
2026-09-26bitmap: bitmap_parse(): reject non-hex character before 8 digitsShashank Mohan Jain
bitmap_parse() is documented to return -EINVAL for illegal characters, and it does so everywhere except when the illegal character directly precedes a chunk of exactly eight hex digits. bitmap_get_x32_reverse() parses a chunk from right to left. After it has consumed eight digits it looks at one more character: a hex digit means the chunk is wider than 32 bits and -EOVERFLOW is returned. Any other character is silently consumed as if it were a separator, and the remaining input is parsed as the next chunk. As a result: "x12345678" -> 0x12345678, returns 0 (expected -EINVAL) "1g12345678" -> 0x1_12345678, returns 0 (expected -EINVAL) "0x0000000f" -> 0xf, returns 0, while "0xf" returns -EINVAL bitmap_parse() backs cpumask_parse() and cpumask_parse_user(), so the same inconsistency is visible when writing masks such as /proc/irq/*/smp_affinity or the network queue rps_cpus/xps_cpus files. __bitmap_parse(), which this function replaced in commit 2d6261583be0 ("lib: rework bitmap_parse()"), rejected all three strings with -EINVAL, and a "0x" prefix is accepted today only when exactly eight digits follow it, so no reliably working input is lost. When the loop falls through, *end is known to be a non-separator character inside the buffer, so return -EOVERFLOW if it is a hex digit and -EINVAL otherwise. Fixes: 2d6261583be0 ("lib: rework bitmap_parse()") Assisted-by: LLM Signed-off-by: Shashank Mohan Jain <jain.sm@gmail.com> Signed-off-by: Yury Norov <ynorov@nvidia.com>
2026-09-25sysctl: Add jiffies converter entries to the test moduleZhan Xusheng
lib/test_sysctl.c covers proc_dointvec(), proc_douintvec(), proc_dostring(), proc_do_large_bitmap() and proc_dou8vec_minmax(), but none of the jiffies converters. Their int paths report the sign separately from the magnitude, which is a shape the existing entries do not exercise at all. Add one entry per affected int converter: proc_dointvec_jiffies(), proc_dointvec_ms_jiffies() and proc_dointvec_userhz_jiffies(). Each is seeded with HZ jiffies, which is one second in every converter's own unit, so the three read back as 1, 1000 and 100 respectively. Signed-off-by: Zhan Xusheng <zhanxusheng@xiaomi.com> Reviewed-by: Bradley Morgan <brads@mainlining.org> Tested-by: Bradley Morgan <brads@mainlining.org> # POWER10 Signed-off-by: Joel Granados <joel.granados@kernel.org>
2026-09-25sysctl: unregister tables before freeing bitmapYibo Tan
The table registered for bitmap_0001 retains a pointer to test_data.bitmap_0001. unregister_sysctl_table() prevents new handlers from starting and waits for active handlers to finish. test_sysctl_exit() currently frees the bitmap before unregistering the table. A concurrent read during module removal can therefore enter proc_do_large_bitmap() while the bitmap is freed. KASAN reports a slab-use-after-free in _find_next_bit(). Unregister all tables before freeing the bitmap so the unregister rundown provides the required lifetime boundary. The unmodified module reproduced the use-after-free in three KASAN runs. With this change, three runs each completed 100 load, read and unload race rounds without a kernel diagnostic. Fixes: 2ea622b887e7 ("tools/testing/selftests/sysctl/sysctl.sh: add proc_do_large_bitmap() test case") Assisted-by: LLM Signed-off-by: Yibo Tan <lhfff@tju.edu.cn> Signed-off-by: Joel Granados <joel.granados@kernel.org>
2026-09-24kobject: fix out-of-bounds access in kobject_action_type()Jiacheng Xu
kobject_action_type() compares the input against each known action using strncmp() and then indexes the action string using count_first to check for an exact-length match. An embedded NUL can make strncmp() return zero even when count_first exceeds the length of the action string. For example, the five-byte input "add\0X" makes the parser access kobject_actions[KOBJ_ADD][5], which is beyond the end of the "add" string. Check the action string length with strlen() instead of indexing it with the input-derived offset. This rejects malformed action strings containing embedded NUL bytes with -EINVAL instead of invoking undefined behavior. Cc: stable@kernel.org Fixes: 60a96a59569b ("Driver core: accept all valid action-strings in uevent-trigger") Signed-off-by: Jiacheng Xu <stitch@zju.edu.cn> Reviewed-by: Vishal Moola (Fractile) <vishal.moola@gmail.com> Link: https://patch.msgid.link/20260920053726.22626-1-stitch@zju.edu.cn Signed-off-by: Danilo Krummrich <dakr@kernel.org>
2026-09-24um: Consolidate MAGIC_SYSRQ into generic Kconfig definitionSasha Levin
kconfiglint reports: K008: config MAGIC_SYSRQ has prompts in 2 separate definitions MAGIC_SYSRQ is defined in two places with complementary conditions: arch/um/Kconfig:213 — depends on MCONSOLE (UML only) lib/Kconfig.debug:665 — depends on !UML (everything except UML) The UML definition has existed since the initial git import in commit 1da177e4c3f4 ("Linux-2.6.12-rc2"). UML needs MAGIC_SYSRQ to work through its mconsole interface rather than through keyboard input, so the UML version depends on MCONSOLE while the generic version excludes UML entirely with `depends on !UML`. These two definitions are logically complementary: on UML, MAGIC_SYSRQ requires MCONSOLE; on everything else, it has no special dependencies. This can be expressed as a single definition with `depends on !UML || MCONSOLE`, which evaluates to: - On UML: requires MCONSOLE (same as before) - On non-UML: always satisfiable (same as before) Consolidate into the generic definition in lib/Kconfig.debug by changing the dependency to `depends on !UML || MCONSOLE` and merging the UML- specific help text that explains the mconsole-based sysrq interface. Remove the now-redundant definition from arch/um/Kconfig. This follows the same unification pattern used by commit 7bd291abe2da ("sched: Unify the SCHED_{SMT,CLUSTER,MC} Kconfig") and our earlier SCHED_MC consolidation for SH. No functional change — the resulting Kconfig behavior is identical. Assisted-by: Claude:claude-opus-4-6 kconfiglint Signed-off-by: Sasha Levin <sashal@kernel.org> Link: https://patch.msgid.link/20260426000339.57049-1-sashal@kernel.org Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2026-09-23lib/842: depend on the decompressor for KUnit testsKarl Mehltretter
842_DECOMPRESS_KUNIT_TEST selects the decompressor even when no other option needs it, including through KUNIT_ALL_TESTS. Depend on 842_DECOMPRESS as required by Documentation/dev-tools/kunit/style.rst. This also prevents the test from promoting a modular decompressor to built-in. Fixes: cca072cb1423 ("lib/842: add KUnit tests for the decompressor") Reported-by: Geert Uytterhoeven <geert@linux-m68k.org> Closes: https://lore.kernel.org/r/CAMuHMdVcZ5cV4-HrjLYfFKh6UshiVxq5eXCNyp0Z1k_SMAvF5g@mail.gmail.com/ Assisted-by: LLM Signed-off-by: Karl Mehltretter <kmehltretter@gmail.com> Acked-by: David Gow <david@davidgow.net> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2026-09-23rhashtable: Use separate lockdep keys for each lockHerbert Xu
Use separate lockdep keys for the different types of locks in rhashtable (mutex, spin lock, and bucket locks). They are separate and not normally nested with respect to each other. Also move the rhashtable_init/rhltable_init kdoc to the header file as that's where the macros are defined. Fixes: 4333ab90aaae ("rhashtable: use private lockdep class for all locks.") Reported-by: syzbot+4d0e4d2db6dfde01b52f@syzkaller.appspotmail.com Assisted-by: Gemini:gemini-3.6-flash Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Reviewed-by: NeilBrown <neil@brown.name> Tested-by: Shin'ichiro Kawasaki <shinichiro.kawasaki@wdc.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2026-09-22umh, treewide: Explicitly include linux/umh.h where neededPetr Pavlu
The usermode helper declarations were previously provided by linux/kmod.h but commit c1f3fa2a4fde ("kmod: split off umh headers into its own file") moved them to linux/umh.h in 2017. Add explicit includes of linux/umh.h to files that use usermode helpers and remove linux/kmod.h where it is no longer needed. Acked-by: Alex Elder <elder@riscstar.com> # for greybus Signed-off-by: Petr Pavlu <petr.pavlu@suse.com>
2026-09-17lib/vsprintf: Use acquire/release for ptr_key publicationJinjie Ruan
Replace the smp_wmb() + WRITE_ONCE() and READ_ONCE() + smp_rmb() barrier pair with smp_store_release()/smp_load_acquire() on filled_random_ptr_key. This expresses the publish/subscribe pattern more clearly and allows architectures with native acquire/release instructions (e.g. arm64's STLR/LDAR) to avoid the cost of full one-way barriers (DMB ISHST/ISHLD). No functional change intended. Cc: Petr Mladek <pmladek@suse.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk> Cc: Sergey Senozhatsky <senozhatsky@chromium.org> Cc: Andrew Morton <akpm@linux-foundation.org> Assisted-by: DeepSeek:DeepSeek-V3 Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com> Reviewed-by: Petr Mladek <pmladek@suse.com> Link: https://patch.msgid.link/20260902074805.398540-3-ruanjinjie@huawei.com Signed-off-by: Petr Mladek <pmladek@suse.com>
2026-09-14Merge tag 'mm-hotfixes-stable-2026-09-13-21-50' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Pull misc fixes from Andrew Morton: "14 hotfixes. 10 are cc:stable. 11 are for MM. All are singletons - please see the changelogs for details" * tag 'mm-hotfixes-stable-2026-09-13-21-50' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: mm/folio: EXPORT_SYMBOL_FOR_KVM(lru_cache_drain_for_folio) mm/shrinker: fix bogus set_shrinker_bit() with cgroup.memory=nokmem mm/vma: correctly unaccount on mmap_prepare() failure mm/mlock: use the IRQ-safe accessor for NR_MLOCK in __munlock_folio() remove old lib/alloc_tag.c fs/dax: check zero or empty entry before converting xarray entry fs: fix missed removal of super_fs_objects_eligible() mm: filemap: retain mapped dropbehind folios mailmap: update entry for Christopher Obbard memcg: avoid charging the root memcg from obj_cgroup_charge_pages() mm, swap: fix SWAP_USAGE_OFFLIST_BIT collision with real usage count mailmap: map Coiby Xu's address mm/mremap: account mm->locked_vm correctly for MREMAP_DONTUNMAP mm/huge_memory: bypass THP tuneables for huge pfnmap mappings
2026-09-11Merge tag 'block-7.3-20260911' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux Pull block fixes from Jens Axboe: - Fix the start and length check added to iov_iter_extract_bvecs(), which used iter_iov_addr()/iter_iov_len() helpers that aren't safe for the ITER_BVEC/FOLIOQ/etc iterator types passed - sunvdc fixes for an -EIO issue from lack of retries, and unmapping LDC cookies when the descriptor send fails - Clear force_abort in ublk_queue_reset_io_flags() - ublk selftest install fix * tag 'block-7.3-20260911' of git://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux: selftests: ublk: add batch IO cases to recover_03 ublk: clear force_abort in ublk_queue_reset_io_flags() sunvdc: fix -EIO issue due to lack of retries sunvdc: unmap LDC cookies when the descriptor send fails block: Fix start and length check added to iov_iter_extract_bvecs() selftests: ublk: install test_common.sh and trace/ scripts
2026-09-11bootconfig: remove redundant assignment in xbc_parse_array()Sang-Heon Jeon
After the loop, node is the last array value that xbc_add_child() added, and xbc_parse_array() sets node->child to 0. xbc_init_node() already set node->child to 0 when the value was added, and node->child is not modified after that, so the assignment is redundant. So remove the assignment. No functional change. Link: https://lore.kernel.org/all/20260910163051.1973775-1-ekffu200098@gmail.com/ Signed-off-by: Sang-Heon Jeon <ekffu200098@gmail.com> Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
2026-09-11bootconfig: merge _xbc_exit() into xbc_exit()Sang-Heon Jeon
Since commit 87ce9e83ab8b ("memblock, treewide: make memblock_free() handle late freeing"), both branches of xbc_free_mem() call memblock_free(), and the early argument has no effect. memblock_free() also does nothing if addr is NULL, so the check before the call is redundant. So remove the argument and the NULL check, and merge _xbc_exit() into xbc_exit(). No functional change. Link: https://lore.kernel.org/all/20260908165712.1703439-1-ekffu200098@gmail.com/ Signed-off-by: Sang-Heon Jeon <ekffu200098@gmail.com> Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
2026-09-11lib/842: add KUnit tests for the decompressorKarl Mehltretter
Add table-driven tests for the 842 decompressor's output and history validation. Three malformed streams cover an indexed copy larger than the remaining output, short data larger than the remaining output, and a repeat after fewer than eight output bytes. Every case checks the return value, output length and fixed guard bands on both sides of the output. Successful cases also check complete contents from a poison-filled destination. The repeat vector's CRC includes the leading guard byte, so the unfixed decoder successfully validates the CRC after reading before the buffer. Three valid streams cover the same boundaries at equality: an I8 index consuming the final eight bytes, five short-data bytes consuming the final five, and a repeat with exactly one block of history. On an unmodified baseline the malformed cases fail and the boundary cases pass; with the preceding fixes all six pass. Assisted-by: LLM Signed-off-by: Karl Mehltretter <kmehltretter@gmail.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2026-09-11lib/842: require a complete history block for repeat templatesKarl Mehltretter
An 842 repeat template copies the preceding eight-byte output block. The decoder rejects a repeat only when no output has been produced. A short-data operation can produce between one and seven bytes before a repeat. Such a stream makes the repeat copy read before the start of the output buffer. Depending on the surrounding mapping, this can fault or bring preceding memory into the decompressed data. This is also reachable through zram's compressed writeback path. With 842 selected, targeted corruption of the compressed data on its backing device to a short-data-then-repeat stream made a KASAN kernel report a vmalloc-out-of-bounds read when zram read the page back. Require at least one complete output block before accepting a repeat. Fixes: 2da572c959dd ("lib: add software 842 compression/decompression") Cc: stable@vger.kernel.org Assisted-by: LLM Signed-off-by: Karl Mehltretter <kmehltretter@gmail.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2026-09-11lib/842: reject output overflows from index and short dataKarl Mehltretter
The output length passed to sw842_decompress() is the caller's buffer capacity. Indexed copies write 2, 4 or 8 bytes and short-data templates write up to 7, but neither checks that capacity before writing and decrementing p->olen. Overwriting an undersized destination then underflows p->olen, which is unsigned, so every later bounds check in the stream passes. Subsequent operations keep writing past the destination, and a matching CRC lets sw842_decompress() return success with an output length larger than the capacity the caller supplied. This is reachable through zram's compressed writeback path. With 842 selected, targeted corruption of the compressed data on its backing device made a KASAN kernel report vmalloc-out-of-bounds writes in __do_index() and sw842_decompress() when zram read the page back. Check the remaining output before both operations and return -ENOSPC, matching the other output-producing templates. Fixes: 2da572c959dd ("lib: add software 842 compression/decompression") Cc: stable@vger.kernel.org Assisted-by: LLM Signed-off-by: Karl Mehltretter <kmehltretter@gmail.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2026-09-10block: Fix start and length check added to iov_iter_extract_bvecs()David Howells
Commit 14b007e17881 added an address check using iter_iov_addr() and a length check using iter_iov_len() to iov_iter_extract_bvecs(), but these cannot be used so and are unsafe in this circumstance as the functions have hardwired assumptions about the iterator type. They should only be used with ITER_UBUF or ITER_IOVEC-type iterators; they shouldn't be used with ITER_BVEC, ITER_KVEC, ITER_FOLIOQ, ITER_XARRAY or ITER_DISCARD iterators. This proves to be a problem for cachefiles as an iterator of type ITER_FOLIOQ is passed and iter_iov_addr() and iter_iov_len() both malfunction because iter->__iov in iter_iov() is not pointing to an iovec array. Fix this by using iov_iter_alignment() instead. Fixes: 14b007e17881 ("block: validate user space vectors during extraction") Signed-off-by: David Howells <dhowells@redhat.com> Reviewed-by: Keith Busch <kbusch@kernel.org> cc: Hannes Reinecke <hare@kernel.org> cc: Christoph Hellwig <hch@infradead.org> cc: Jens Axboe <axboe@kernel.dk> cc: Alexander Viro <viro@zeniv.linux.org.uk> cc: Paulo Alcantara <pc@manguebit.org> cc: netfs@lists.linux.dev cc: linux-block@vger.kernel.org cc: linux-fsdevel@vger.kernel.org Reviewed-by: Christoph Hellwig <hch@lst.de> Link: https://patch.msgid.link/1667275.1788941191@warthog.procyon.org.uk Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-09-10xor: Add AVX-512 optimized xor_gen()Eric Biggers
Add an implementation of xor_gen() using AVX-512. It uses 512-bit vectors, i.e. ZMM registers. It also uses the vpternlogq instruction to do three-input XORs when applicable. It's enabled on x86_64 CPUs that have AVX512F && !PREFER_YMM. In practice that means: - AMD Zen 4 and later (client and server) - Intel Sapphire Rapids and later (server) - Intel Rocket Lake (client) - Intel Nova Lake and later (client) The !PREFER_YMM condition excludes the older AVX-512 implementations in Intel Skylake Server and Intel Ice Lake. They could run this code, but they're known to have overly-eager downclocking when ZMM registers are used. This is the same policy that the crypto and CRC code uses. Results from xor_benchmark on AMD Ryzen 9 9950X (Zen 5): Before: # xor_benchmark: 4096 bytes 16384 bytes # xor_benchmark: 4 disks: 256 GB/s 185 GB/s # xor_benchmark: 5 disks: 233 GB/s 165 GB/s # xor_benchmark: 6 disks: 243 GB/s 174 GB/s # xor_benchmark: 7 disks: 244 GB/s 176 GB/s # xor_benchmark: 8 disks: 265 GB/s 179 GB/s # xor_benchmark: 10 disks: 249 GB/s 175 GB/s # xor_benchmark: 12 disks: 219 GB/s 173 GB/s # xor_benchmark: 15 disks: 206 GB/s 177 GB/s # xor_benchmark: 16 disks: 212 GB/s 180 GB/s # xor_benchmark: 32 disks: 193 GB/s 177 GB/s After: # xor_benchmark: 4096 bytes 16384 bytes # xor_benchmark: 4 disks: 492 GB/s 202 GB/s # xor_benchmark: 5 disks: 436 GB/s 191 GB/s # xor_benchmark: 6 disks: 466 GB/s 193 GB/s # xor_benchmark: 7 disks: 491 GB/s 194 GB/s # xor_benchmark: 8 disks: 513 GB/s 205 GB/s # xor_benchmark: 10 disks: 454 GB/s 199 GB/s # xor_benchmark: 12 disks: 330 GB/s 204 GB/s # xor_benchmark: 15 disks: 266 GB/s 198 GB/s # xor_benchmark: 16 disks: 243 GB/s 177 GB/s # xor_benchmark: 32 disks: 187 GB/s 165 GB/s Signed-off-by: Eric Biggers <ebiggers@kernel.org> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Reviewed-by: David Laight <david.laight.linux@gmail.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Acked-by: Christoph Hellwig <hch@lst.de> Link: https://patch.msgid.link/20260901145740.42337-9-ebiggers@kernel.org
2026-09-10xor: Remove redundant X86_FEATURE_OSXSAVE checkEric Biggers
X86_FEATURE_AVX implies X86_FEATURE_OSXSAVE already. Signed-off-by: Eric Biggers <ebiggers@kernel.org> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Reviewed-by: Christoph Hellwig <hch@lst.de> Acked-by: Christoph Hellwig <hch@lst.de> Link: https://patch.msgid.link/20260901145740.42337-8-ebiggers@kernel.org
2026-09-09lib/crc: x86: Stop using cpu_has_xfeatures()Eric Biggers
Checking both boot_cpu_has() and cpu_has_xfeatures() has never really been needed in practice, and it's never been universally done (e.g., lib/raid/ omits cpu_has_xfeatures()). Nevertheless, both x86 and UML now explicitly clear the AVX and AVX-512 flags if their xfeatures are missing, which should remove any remaining doubts. Thus, remove all the calls to cpu_has_xfeatures(). Signed-off-by: Eric Biggers <ebiggers@kernel.org> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Acked-by: Christoph Hellwig <hch@lst.de> Link: https://patch.msgid.link/20260901145740.42337-6-ebiggers@kernel.org
2026-09-08lib/crypto: x86: Stop using cpu_has_xfeatures()Eric Biggers
Checking both boot_cpu_has() and cpu_has_xfeatures() has never really been needed in practice, and it's never been universally done (e.g., lib/raid/ omits cpu_has_xfeatures()). Nevertheless, both x86 and UML now explicitly clear the AVX and AVX-512 flags if their xfeatures are missing, which should remove any remaining doubts. Thus, remove all the calls to cpu_has_xfeatures(). Signed-off-by: Eric Biggers <ebiggers@kernel.org> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Acked-by: Christoph Hellwig <hch@lst.de> Link: https://patch.msgid.link/20260901145740.42337-5-ebiggers@kernel.org
2026-09-05remove old lib/alloc_tag.cAndrew Morton
This was moved into mm/, but the original lib/ file somehow remained. Remove it. Reported-by: Suren Baghdasaryan <surenb@google.com> Cc: Lorenzo Stoakes <ljs@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-09-04treewide: refresh kmalloc_obj() conversionsKees Cook
This is another run of the Coccinelle script for converting kmalloc() family of allocations to kmalloc_obj() via the existing rules in scripts/coccinelle/api/kmalloc_objs.cocci This catches both the set of kmalloc() uses added since the first kmalloc_obj() conversions in v7.0 and adds a large group missed in the first pass due to Coccinelle not interacting well with the cleanup.h scoped_...() family of macros[1]. I worked around this with spatch's "--macro-file" argument to a file with all the scoped_...() macros mapped to Coccinelle's YACFE_ITERATOR[2] as that was the closest viable control flow indicator I could find. Build tested allmodconfig on x86, arm64, arm, loongarch, mips, powerpc, riscv, and s390 with no new warnings. Link: https://lore.kernel.org/lkml/202609021314.8A9C0B8@keescook/ [1] Link: https://github.com/coccinelle/coccinelle/blob/master/standard.h [2] Signed-off-by: Kees Cook <kees+treewide@kernel.org>
2026-09-04rhashtable: use private lockdep class for all locks.NeilBrown
This patch builds on Commit: 060d4e94b8d4 ("rhashtable: give each instance its own lockdep class") to allow lockdep to see each rhashtable as unique with respect to all of the locks, not just the ht->mutex. This is needed if rhashtable is to be used tracepoint BPF which could run while an rhashtable lock (in a different table) is held - see Link below. Rather then adding extra keys for the other locks, we use distinct sub-classes for the different locks. rhashtable->lock uses class 0 rhashtable->mutex uses class 1 bucket bitlocks, which are the only ones that are ever nested, use classes 2 and 3. Currently rht_lock() and rht_lock_nested() are quite separate code despite the near-identical function. This patch moves rht_lock() to after rht_lock_nested(), and simply calls that other function with a nesting level of zero. Link: https://lore.kernel.org/all/20260801-fix-rhashtable-bucket-lockdep-v1-1-15a0f8ae094c@gmail.com/ Closes: https://syzkaller.appspot.com/bug?extid=ef8d17bae14efb960935 Tested-by: quanyeyang <quanyeyang@proton.me> Signed-off-by: NeilBrown <neil@brown.name> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2026-09-03lib/test_csd_lock: Add a module to stall a CPU on a CSD lockBreno Leitao
Add test_csd_lock, a module that keeps one CPU from answering an IPI for as long as its stall_ms parameter says, so that the CSD-lock debug code has a stall to report. With in_handler=1 the CPU stalls inside a CSD handler instead, which is the case where the IPI is not re-sent. The module needs CONFIG_CSD_LOCK_WAIT_DEBUG and csdlock_debug=1. Loading it runs one stall and then fails the load with -EAGAIN, the way test_lockup does, so that nothing is left loaded afterwards. Signed-off-by: Breno Leitao <leitao@debian.org> Signed-off-by: Paul E. McKenney <paulmck@kernel.org> Cc: Andrew Morton <akpm@linux-foundation.org>
2026-09-02kunit: Return void from kunit_run_all_tests()Thomas Weißschuh
No caller tests the return value of this function. The integer return type is still a remnant from when the function was executed as initcall. This usage however was removed in commit 8c0d884986ba ("init: main: add KUnit to kernel init") Link: https://lore.kernel.org/r/20260901-kunit-void-v1-1-c91952391d66@linutronix.de Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de> Reviewed-by: David Gow <david@davidgow.net> Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
2026-09-01Revert "once: don't use a work queue to reset sleepable static key"Eric Dumazet
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 <edumazet@google.com> Closes: https://lore.kernel.org/lkml/ao0mwtt8ePAINFni@shinhome/ Reported-by: Shin'ichiro Kawasaki <shinichiro.kawasaki@wdc.com> Cc: Tony Luck <tony.luck@intel.com> Cc: Reinette Chatre <reinette.chatre@intel.com> Cc: Keith Busch <kbusch@kernel.org> Cc: Nilay Shroff <nilay@linux.ibm.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-08-27Merge tag 'mm-stable-2026-08-26-15-22' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm 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 ...
2026-08-25Merge tag 'char-misc-7.3-rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc 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 ...
2026-08-25Merge tag 'bootconfig-v7.3' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace 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
2026-08-24maple_tree: add helper mas_make_walkable()Liam R. Howlett (Oracle)
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) <liam@infradead.org> Cc: Boqun Feng <boqun.feng@gmail.com> Cc: Breno Leitao <leitao@debian.org> Cc: Chris Mason <clm@meta.com> Cc: Chuck Lever <cel@kernel.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: Joe Perches <joe@perches.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@surriel.com> Cc: Waiman Long <longman@redhat.com> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-08-24maple_tree: avoid extra gap calculationLiam R. Howlett (Oracle)
Prior to ending the ascension loop of larger operations like split, rebalance, and spanning store the gap in the node had been calculated. Once the node is inserted into the tree, the gap is recalculated in mas_update_gap(). This can be avoided by creating a helper for mas_update_gap() that accepts the known gap value, which reduces the operations required for gap updating path. Link: https://lore.kernel.org/20260821192627.4085470-19-liam@infradead.org Signed-off-by: Liam R. Howlett (Oracle) <liam@infradead.org> Cc: Boqun Feng <boqun.feng@gmail.com> Cc: Breno Leitao <leitao@debian.org> Cc: Chris Mason <clm@meta.com> Cc: Chuck Lever <cel@kernel.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: Joe Perches <joe@perches.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@surriel.com> Cc: Waiman Long <longman@redhat.com> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-08-24maple_tree: avoid mas_erase() and mtree_erase() failuresLiam R. Howlett (Oracle)
Failures to remove entries using the two APIs to erase the entries may result in allocation failures. The failures may go unnoticed and an unexpected entry may remain. Instead, fall back to retrying with GFP_KERNEL | __GFP_NOFAIL so that the entry will be removed. Link: https://lore.kernel.org/20260821192627.4085470-15-liam@infradead.org Signed-off-by: Liam R. Howlett (Oracle) <liam@infradead.org> Cc: Rik van Riel <riel@surriel.com> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: Boqun Feng <boqun.feng@gmail.com> Cc: Breno Leitao <leitao@debian.org> Cc: Chris Mason <clm@meta.com> Cc: Chuck Lever <cel@kernel.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Joe Perches <joe@perches.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Waiman Long <longman@redhat.com> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-08-24maple_tree: document that erase may use GFP_KERNEL for allocationsLiam R. Howlett (Oracle)
State that the mas_erase() and mtree_erase() functions may use GFP_KERNEL on allocation retry. Don't just depend on people reading the documentation by adding a check that will warn of the use. Link: https://lore.kernel.org/20260821192627.4085470-14-liam@infradead.org Signed-off-by: Liam R. Howlett (Oracle) <liam@infradead.org> Reviewed-by: Rik van Riel <riel@surriel.com> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: Boqun Feng <boqun.feng@gmail.com> Cc: Breno Leitao <leitao@debian.org> Cc: Chris Mason <clm@meta.com> Cc: Chuck Lever <cel@kernel.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Joe Perches <joe@perches.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Waiman Long <longman@redhat.com> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-08-24maple_tree: catch race in mas_alloc_cyclic()Liam R. Howlett (Oracle)
If mas_alloc_cyclic() is called during a low memory situation, it is possible the lock may be dropped so reclaim can occur. There is a window where some other task may allocate the same id and cause the mas_insert() to fail with -EEXIST. In this scenario the function will return -EEXIST, which is not expected. Modifying the retry on mas_nomem() to re-search for a slot means that any race with other writes will not matter as the lock will be held between finding the index and writing the index. Moving the flag logic avoids cases where the flag is modified on drop lock/reacquire or when the write fails after clearing the flag. No existing users are exposed to this issue. Link: https://lore.kernel.org/20260821192627.4085470-13-liam@infradead.org Fixes: 9b6713cc7522 ("maple_tree: Add mtree_alloc_cyclic()") Signed-off-by: Liam R. Howlett (Oracle) <liam@infradead.org> Reported-by: Chris Mason <clm@meta.com> Reviewed-by: Chuck Lever <cel@kernel.org> Cc: Boqun Feng <boqun.feng@gmail.com> Cc: Breno Leitao <leitao@debian.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: Joe Perches <joe@perches.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@surriel.com> Cc: Waiman Long <longman@redhat.com> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-08-24maple_tree: add bulk parent set helperLiam R. Howlett (Oracle)
Instead of calculating the parent pointer each time for a child, cache the majority of the parent pointer and only change the slot per child. Drop the mas_set_parent() function since the last user has been removed. Testing on a tree containing 2048 entries of height 4 had an increased gain of 3.51% on nodes tracking gaps. Link: https://lore.kernel.org/20260821192627.4085470-12-liam@infradead.org Signed-off-by: Liam R. Howlett (Oracle) <liam@infradead.org> Cc: Boqun Feng <boqun.feng@gmail.com> Cc: Breno Leitao <leitao@debian.org> Cc: Chris Mason <clm@meta.com> Cc: Chuck Lever <cel@kernel.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: Joe Perches <joe@perches.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@surriel.com> Cc: Waiman Long <longman@redhat.com> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-08-24maple_tree: micro optimisation of mas_wr_store_type()Liam R. Howlett (Oracle)
Use three new local booleans instead of reading other structures. This has shown an increase of 0.62% on a 2048 entry tree of height 4. Link: https://lore.kernel.org/20260821192627.4085470-11-liam@infradead.org Signed-off-by: Liam R. Howlett (Oracle) <liam@infradead.org> Cc: Boqun Feng <boqun.feng@gmail.com> Cc: Breno Leitao <leitao@debian.org> Cc: Chris Mason <clm@meta.com> Cc: Chuck Lever <cel@kernel.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: Joe Perches <joe@perches.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@surriel.com> Cc: Waiman Long <longman@redhat.com> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-08-24maple_tree: optimise mas_wr_node_store() when not in rcu modeLiam R. Howlett (Oracle)
Clearing the entire node on the stack is unnecessary since most of the node will be overwritten anyways. Just clear what isn't used after the data is in place. Benchmarking shows a speedup of 0.67% on a height 4 tree with 2048 entries. Link: https://lore.kernel.org/20260821192627.4085470-10-liam@infradead.org Signed-off-by: Liam R. Howlett (Oracle) <liam@infradead.org> Cc: Boqun Feng <boqun.feng@gmail.com> Cc: Breno Leitao <leitao@debian.org> Cc: Chris Mason <clm@meta.com> Cc: Chuck Lever <cel@kernel.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: Joe Perches <joe@perches.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@surriel.com> Cc: Waiman Long <longman@redhat.com> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-08-24maple_tree: use prefetched value in mas_wr_store_type()Liam R. Howlett (Oracle)
The slot contents exist in wr_mas->content, which has less overhead than reading the slot again. Link: https://lore.kernel.org/20260821192627.4085470-9-liam@infradead.org Signed-off-by: Liam R. Howlett (Oracle) <liam@infradead.org> Cc: Boqun Feng <boqun.feng@gmail.com> Cc: Breno Leitao <leitao@debian.org> Cc: Chris Mason <clm@meta.com> Cc: Chuck Lever <cel@kernel.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: Joe Perches <joe@perches.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@surriel.com> Cc: Waiman Long <longman@redhat.com> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-08-24maple_tree: clarify comments on mas_nomem()Liam R. Howlett (Oracle)
When an allocation completely fails, the return is false. If the allocation succeeds or partially succeeds, return true to indicate a retry of the operation. Note that since the lock may have been dropped, the operation is retried from the start - including potentially allocating more memory. Link: https://lore.kernel.org/20260821192627.4085470-8-liam@infradead.org Signed-off-by: Liam R. Howlett (Oracle) <liam@infradead.org> Cc: Boqun Feng <boqun.feng@gmail.com> Cc: Breno Leitao <leitao@debian.org> Cc: Chris Mason <clm@meta.com> Cc: Chuck Lever <cel@kernel.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: Joe Perches <joe@perches.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@surriel.com> Cc: Waiman Long <longman@redhat.com> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-08-24maple_tree: drop dead code from mas_extend_spanning_null()Liam R. Howlett (Oracle)
mas_extend_spanning_null() had a clause if the end of the range being written (mas->last) is the same as the end of the existing range it is overwriting (wr_mas->r_max), action will be taken. This code path is not possible because the only calling function increments mas->last (unless it's ULONG_MAX) to walk to one beyond the write and then resets the value back to the initial value. In the case of mas->last == ULONG_MAX, then the second part of the statement will always be false - mas->last cannot be less than the node max. This code never executed and is flawed anyways (the arguments are incorrectly ordered), so removing it is the safest action. Since the code never executes, it is not fixing any issue so Fixes tag is not given. Link: https://lore.kernel.org/20260821192627.4085470-6-liam@infradead.org Signed-off-by: Liam R. Howlett (Oracle) <liam@infradead.org> Cc: Boqun Feng <boqun.feng@gmail.com> Cc: Breno Leitao <leitao@debian.org> Cc: Chris Mason <clm@meta.com> Cc: Chuck Lever <cel@kernel.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: Joe Perches <joe@perches.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@surriel.com> Cc: Waiman Long <longman@redhat.com> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-08-24maple_tree: add write lock checking with lockdep sequence numbersLiam R. Howlett (Oracle)
Use the lockdep sequence numbers to ensure the write lock is not dropped between write operations. The lockdep sequence is recorded on any walk that starts from the top of the tree and re-checked prior to any operation using an active node. When lockdep detects an issue, it sets debug_locks to 0 disabling further reports. __lock_sequnece() will return u32 ~0 when debug_locks is zero, and the real sequnece count cannot return such a high value as it is less than 32bits. By always updating the sequence number, regardless of lock state and by ignoring ~0 value in the sequence number will avoid ever printing a WARN_ON when lockdep sets debug_locks to 0. Link: https://lore.kernel.org/20260821192627.4085470-4-liam@infradead.org Signed-off-by: Liam R. Howlett (Oracle) <liam@infradead.org> Cc: Breno Leitao <leitao@debian.org> Tested-by: Breno Leitao <leitao@debian.org> Cc: Boqun Feng <boqun.feng@gmail.com> Cc: Chris Mason <clm@meta.com> Cc: Chuck Lever <cel@kernel.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: Joe Perches <joe@perches.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@surriel.com> Cc: Waiman Long <longman@redhat.com> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-08-24maple_tree: add rcu locking check when LOCKDEP is enabledLiam R. Howlett (Oracle)
Patch series "maple_tree: lock checking and clean ups", v3. In this series: 1. Try to detect lock issues A number of syzbot reports are incorrectly pointing to the mm exit as a source of the locking error. The first three patches attempt to help users detect errors in their locking - but they still have to use LOCKDEP. I guess it's still down to hope and prayers. 2. Documentation fixes The documentation was lacking clarity, there are updates to try and help the users, especially around the erase() cases. 3. Two benign issues The cyclic allocator may have a race, although no in-kernel user can hit it. The erase functions may cause allocation issues if used with the incorrect locking type, but none are present in-tree. 4. The erase gfp uses mas_erase() and mtree_erase() do not take a gfp argument. To improve reliability of the erase, the first attempt to allocate will be GFP_NOWAIT, followed by a retry (if necessary of GFP_KERNEL | GFP_NOFAIL. This will ensure the data is gone. I've updated the documentation to make it more clear as well. mas_store() is not addressed in the same way, but may need to be updated at a later date, but that may require changing callers so it is out of scope here. Beyond these goals there are some test fixes, some general speed-up patches targeting extra work and cycles, and dropping dead code. This patch (of 19): When CONFIG_LOCKDEP and CONFIG_RCU_STRICT_GRACE_PERIOD is enabled, check for rcu locking issues by recording the grace period in the maple state and checking the rcu window is still valid whenever the maple state is reused with a state that is not MA_START or MA_PAUSED. Link: https://lore.kernel.org/20260821192627.4085470-1-liam@infradead.org Link: https://lore.kernel.org/20260821192627.4085470-2-liam@infradead.org Signed-off-by: Liam R. Howlett (Oracle) <liam@infradead.org> Cc: Boqun Feng <boqun.feng@gmail.com> Cc: Breno Leitao <leitao@debian.org> Cc: Chris Mason <clm@meta.com> Cc: Chuck Lever <cel@kernel.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: Joe Perches <joe@perches.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@surriel.com> Cc: Waiman Long <longman@redhat.com> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-08-24lib/test_hmm: fix garbage pfn and wrong direction in devmem fault debugQiang Liu
Move pr_debug() inside the `if (dpage)` block to avoid printing garbage pfn for NULL dpage, and correct the direction label from "sys to dev" to "dev to sys". Link: https://lore.kernel.org/20260812092856.55296-1-liuqiangneo@163.com Signed-off-by: Qiang Liu <liuqiang@kylinos.cn> Assisted-by: Qoder:Qwen-3.8-MAX-Preview Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: Leon Romanovsky <leon@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-08-24percpu: drop CONFIG_DEBUG_FORCE_WEAK_PER_CPUTejun Heo
alpha requires percpu variables in modules to be defined as weak so that the compiler generates GOT based external references for them. This puts two extra restrictions on percpu variable definitions. The symbol must be globally unique even when static and a static percpu variable can't be defined inside a function. DEBUG_FORCE_WEAK_PER_CPU exists to give generic code build coverage for these restrictions without building for alpha. MEM_ALLOC_PROFILING defines a static percpu counter at each allocation call site and thus can't be built with weak percpu definitions, so it depends on !DEBUG_FORCE_WEAK_PER_CPU. As allmodconfig enables DEBUG_FORCE_WEAK_PER_CPU, this knocks MEM_ALLOC_PROFILING out of allmodconfig build coverage. allmodconfig coverage for MEM_ALLOC_PROFILING is worth more than build coverage for restrictions which only matter to alpha module builds. Drop DEBUG_FORCE_WEAK_PER_CPU. Restriction violations will now show up only on alpha builds. Link: https://lore.kernel.org/178656406317.2437052.7257990869957704195@slm.duckdns.org Signed-off-by: Tejun Heo <tj@kernel.org> Reported-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Suren Baghdasaryan <surenb@google.com> Acked-by: Gabriele Monaco <gmonaco@redhat.com> [include/rv/da_monitor.h] Cc: Dennis Zhou <dennis@kernel.org> Cc: Kent Overstreet <kent.overstreet@linux.dev> Cc: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-08-24maple_tree: fix comment typoMark Sercombe
Fix a spelling mistake n a code comment. This is a comment only change with no functional impact. Link: https://lore.kernel.org/20260813183847.474357-1-sercombe.joel.mark@gmail.com Signed-off-by: Mark Sercombe <sercombe.joel.mark@gmail.com> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Liam R. Howlett (Oracle) <liam@infradead.org> Cc: Alice Ryhl <aliceryhl@google.com> Cc: Andrew Ballance <andrewjballance@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>