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7 daysMerge tag 'slab-for-6.15-rc5' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/vbabka/slab Pull slab fix from Vlastimil Babka: - Stable fix to avoid bugs due to leftover obj_ext after allocation profiling is disabled at runtime (Zhenhua Huang) * tag 'slab-for-6.15-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/vbabka/slab: mm, slab: clean up slab->obj_exts always
10 daysMerge tag 'fixes-2025-04-29' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/rppt/memblock Pull memblock fixes from Mike Rapoport: "Fixes for nid setting in memmap_init_reserved_pages(): - pass 'size' rather than 'end' to memblock_set_node() as that function expects - fix a corner case when memblock.reserved is doubled at memmap_init_reserved_pages() and the newly reserved block won't have nid assigned" * tag 'fixes-2025-04-29' of git://git.kernel.org/pub/scm/linux/kernel/git/rppt/memblock: memblock tests: add test for memblock_set_node mm/memblock: repeat setting reserved region nid if array is doubled mm/memblock: pass size instead of end to memblock_set_node()
2025-04-24mm, slab: clean up slab->obj_exts alwaysZhenhua Huang
When memory allocation profiling is disabled at runtime or due to an error, shutdown_mem_profiling() is called: slab->obj_exts which previously allocated remains. It won't be cleared by unaccount_slab() because of mem_alloc_profiling_enabled() not true. It's incorrect, slab->obj_exts should always be cleaned up in unaccount_slab() to avoid following error: [...]BUG: Bad page state in process... .. [...]page dumped because: page still charged to cgroup [andriy.shevchenko@linux.intel.com: fold need_slab_obj_ext() into its only user] Fixes: 21c690a349ba ("mm: introduce slabobj_ext to support slab object extensions") Cc: stable@vger.kernel.org Signed-off-by: Zhenhua Huang <quic_zhenhuah@quicinc.com> Acked-by: David Rientjes <rientjes@google.com> Acked-by: Harry Yoo <harry.yoo@oracle.com> Tested-by: Harry Yoo <harry.yoo@oracle.com> Acked-by: Suren Baghdasaryan <surenb@google.com> Link: https://patch.msgid.link/20250421075232.2165527-1-quic_zhenhuah@quicinc.com Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
2025-04-22mm/migrate: fix sleep in atomic for large folios and buffer headsDavidlohr Bueso
The large folio + buffer head noref migration scenarios are being naughty and blocking while holding a spinlock. As a consequence of the pagecache lookup path taking the folio lock this serializes against migration paths, so they can wait for each other. For the private_lock atomic case, a new BH_Migrate flag is introduced which enables the lookup to bail. This allows the critical region of the private_lock on the migration path to be reduced to the way it was before ebdf4de5642fb6 ("mm: migrate: fix reference check race between __find_get_block() and migration"), that is covering the count checks. The scope is always noref migration. Reported-by: kernel test robot <oliver.sang@intel.com> Reported-by: syzbot+f3c6fda1297c748a7076@syzkaller.appspotmail.com Closes: https://lore.kernel.org/oe-lkp/202503101536.27099c77-lkp@intel.com Fixes: 3c20917120ce61 ("block/bdev: enable large folio support for large logical block sizes") Reviewed-by: Jan Kara <jack@suse.cz> Co-developed-by: Luis Chamberlain <mcgrof@kernel.org> Signed-off-by: Davidlohr Bueso <dave@stgolabs.net> Link: https://kdevops.org/ext4/v6.15-rc2.html # [0] Link: https://lore.kernel.org/all/aAAEvcrmREWa1SKF@bombadil.infradead.org/ # [1] Link: https://lore.kernel.org/20250418015921.132400-8-dave@stgolabs.net Tested-by: kdevops@lists.linux.dev # [0] [1] Reviewed-by: Luis Chamberlain <mcgrof@kernel.org> Signed-off-by: Christian Brauner <brauner@kernel.org>
2025-04-19Merge tag 'mm-hotfixes-stable-2025-04-19-21-24' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Pull misc hotfixes from Andrew Morton: "16 hotfixes. 2 are cc:stable and the remainder address post-6.14 issues or aren't considered necessary for -stable kernels. All patches are basically for MM although five are alterations to MAINTAINERS" [ Basic counting skills are clearly not a strictly necessary requirement for kernel maintainers. - Linus ] * tag 'mm-hotfixes-stable-2025-04-19-21-24' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: MAINTAINERS: add section for locking of mm's and VMAs mm: vmscan: fix kswapd exit condition in defrag_mode mm: vmscan: restore high-cpu watermark safety in kswapd MAINTAINERS: add Pedro as reviewer to the MEMORY MAPPING section mm/memory: move sanity checks in do_wp_page() after mapcount vs. refcount stabilization mm, hugetlb: increment the number of pages to be reset on HVO writeback: fix false warning in inode_to_wb() docs: ABI: replace mcroce@microsoft.com with new Meta address mm/gup: fix wrongly calculated returned value in fault_in_safe_writeable() MAINTAINERS: add memory advice section MAINTAINERS: add mmap trace events to MEMORY MAPPING mm: memcontrol: fix swap counter leak from offline cgroup MAINTAINERS: add MM subsection for the page allocator MAINTAINERS: update SLAB ALLOCATOR maintainers fs/dax: fix folio splitting issue by resetting old folio order + _nr_pages mm/page_alloc: fix deadlock on cpu_hotplug_lock in __accept_page()
2025-04-18Merge tag 'hardening-v6.15-rc3' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux Pull hardening fixes from Kees Cook: - lib/prime_numbers: KUnit test should not select PRIME_NUMBERS (Geert Uytterhoeven) - ubsan: Fix panic from test_ubsan_out_of_bounds (Mostafa Saleh) - ubsan: Remove 'default UBSAN' from UBSAN_INTEGER_WRAP (Nathan Chancellor) - string: Add load_unaligned_zeropad() code path to sized_strscpy() (Peter Collingbourne) - kasan: Add strscpy() test to trigger tag fault on arm64 (Vincenzo Frascino) - Disable GCC randstruct for COMPILE_TEST * tag 'hardening-v6.15-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux: lib/prime_numbers: KUnit test should not select PRIME_NUMBERS ubsan: Fix panic from test_ubsan_out_of_bounds lib/Kconfig.ubsan: Remove 'default UBSAN' from UBSAN_INTEGER_WRAP hardening: Disable GCC randstruct for COMPILE_TEST kasan: Add strscpy() test to trigger tag fault on arm64 string: Add load_unaligned_zeropad() code path to sized_strscpy()
2025-04-17mm: vmscan: fix kswapd exit condition in defrag_modeJohannes Weiner
Vlastimil points out an issue with kswapd in defrag_mode not waking up kcompactd reliably. Background: When kswapd is woken for any higher-order request, it initially checks those high-order watermarks to decide if work is necesary. However, it cannot (efficiently) meet the contiguity goal of such a request by itself. So once it has reclaimed a compaction gap, it adjusts the request down to check for free order-0 pages, then wakes kcompactd to coalesce them into larger blocks. In defrag_mode, the initial watermark check needs to be analogously against free pageblocks. However, once kswapd drops the high-order to hand off contiguity work, it also needs to fall back to base page watermarks - otherwise it'll keep reclaiming until blocks are freed. While it appears kcompactd is woken up frequently enough to do most of the compaction work, kswapd ends up overreclaiming by quite a bit: DEFRAGMODE DEFRAGMODE-thispatch Hugealloc Time mean 79381.34 ( +0.00%) 88126.12 ( +11.02%) Hugealloc Time stddev 85852.16 ( +0.00%) 135366.75 ( +57.67%) Kbuild Real time 249.35 ( +0.00%) 226.71 ( -9.04%) Kbuild User time 1249.16 ( +0.00%) 1249.37 ( +0.02%) Kbuild System time 171.76 ( +0.00%) 166.93 ( -2.79%) THP fault alloc 51666.87 ( +0.00%) 52685.60 ( +1.97%) THP fault fallback 16970.00 ( +0.00%) 15951.87 ( -6.00%) Direct compact fail 166.53 ( +0.00%) 178.93 ( +7.40%) Direct compact success 17.13 ( +0.00%) 4.13 ( -71.69%) Compact daemon scanned migrate 3095413.33 ( +0.00%) 9231239.53 ( +198.22%) Compact daemon scanned free 2155966.53 ( +0.00%) 7053692.87 ( +227.17%) Compact direct scanned migrate 265642.47 ( +0.00%) 68388.33 ( -74.26%) Compact direct scanned free 130252.60 ( +0.00%) 55634.87 ( -57.29%) Compact total migrate scanned 3361055.80 ( +0.00%) 9299627.87 ( +176.69%) Compact total free scanned 2286219.13 ( +0.00%) 7109327.73 ( +210.96%) Alloc stall 1890.80 ( +0.00%) 6297.60 ( +232.94%) Pages kswapd scanned 9043558.80 ( +0.00%) 5952576.73 ( -34.18%) Pages kswapd reclaimed 1891708.67 ( +0.00%) 1030645.00 ( -45.52%) Pages direct scanned 1017090.60 ( +0.00%) 2688047.60 ( +164.29%) Pages direct reclaimed 92682.60 ( +0.00%) 309770.53 ( +234.22%) Pages total scanned 10060649.40 ( +0.00%) 8640624.33 ( -14.11%) Pages total reclaimed 1984391.27 ( +0.00%) 1340415.53 ( -32.45%) Swap out 884585.73 ( +0.00%) 417781.93 ( -52.77%) Swap in 287106.27 ( +0.00%) 95589.73 ( -66.71%) File refaults 551697.60 ( +0.00%) 426474.80 ( -22.70%) Link: https://lkml.kernel.org/r/20250416135142.778933-3-hannes@cmpxchg.org Fixes: a211c6550efc ("mm: page_alloc: defrag_mode kswapd/kcompactd watermarks") Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Reported-by: Vlastimil Babka <vbabka@suse.cz> Reviewed-by: Vlastimil Babka <vbabka@suse.cz> Cc: Brendan Jackman <jackmanb@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-04-17mm: vmscan: restore high-cpu watermark safety in kswapdJohannes Weiner
Vlastimil points out that commit a211c6550efc ("mm: page_alloc: defrag_mode kswapd/kcompactd watermarks") switched kswapd from zone_watermark_ok_safe() to the standard, percpu-cached version of reading free pages, thus dropping the watermark safety precautions for systems with high CPU counts (e.g. >212 cpus on 64G). Restore them. Since zone_watermark_ok_safe() is no longer the right interface, and this was the last caller of the function anyway, open-code the zone_page_state_snapshot() conditional and delete the function. Link: https://lkml.kernel.org/r/20250416135142.778933-2-hannes@cmpxchg.org Fixes: a211c6550efc ("mm: page_alloc: defrag_mode kswapd/kcompactd watermarks") Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Reported-by: Vlastimil Babka <vbabka@suse.cz> Reviewed-by: Vlastimil Babka <vbabka@suse.cz> Cc: Brendan Jackman <jackmanb@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-04-17mm/memory: move sanity checks in do_wp_page() after mapcount vs. refcount ↵David Hildenbrand
stabilization In __folio_remove_rmap() for RMAP_LEVEL_PMD/RMAP_LEVEL_PUD and with CONFIG_PAGE_MAPCOUNT we first decrement the folio mapcount (and recompute mapped shared vs. mapped exclusively) to then adjust the entire mapcount. This means that another process might stumble in do_wp_page() over a PTE-mapped PMD folio that is indicated as "exclusively mapped", but still has an entire mapcount (PMD mapping), because it is racing with the process that is unmapping the folio (PMD mapping). Note that do_wp_page() will back off once it detects the remaining folio reference from the process that is in the process of unmapping the folio. This will trigger the early VM_WARN_ON_ONCE(folio_entire_mapcount(folio)) check in do_wp_page(), that can easily be reproduced by looping a couple of times over allocating a PMD THP, forking a child where we immediately unmap it again, and writing in the parent concurrently to the THP. [ 252.738129][T16470] ------------[ cut here ]------------ [ 252.739267][T16470] WARNING: CPU: 3 PID: 16470 at mm/memory.c:3738 do_wp_page+0x2a75/0x2c00 [ 252.740968][T16470] Modules linked in: [ 252.741958][T16470] CPU: 3 UID: 0 PID: 16470 Comm: ... ... [ 252.765841][T16470] <TASK> [ 252.766419][T16470] ? srso_alias_return_thunk+0x5/0xfbef5 [ 252.767558][T16470] ? rcu_is_watching+0x12/0x60 [ 252.768525][T16470] ? srso_alias_return_thunk+0x5/0xfbef5 [ 252.769645][T16470] ? srso_alias_return_thunk+0x5/0xfbef5 [ 252.770778][T16470] ? lock_acquire+0x33/0x80 [ 252.771697][T16470] ? __handle_mm_fault+0x5e8/0x3e40 [ 252.772735][T16470] ? __handle_mm_fault+0x5e8/0x3e40 [ 252.773781][T16470] __handle_mm_fault+0x1869/0x3e40 [ 252.774839][T16470] handle_mm_fault+0x22a/0x640 [ 252.775808][T16470] do_user_addr_fault+0x618/0x1000 [ 252.776847][T16470] exc_page_fault+0x68/0xd0 [ 252.777775][T16470] asm_exc_page_fault+0x26/0x30 While we could adjust the sequence in __folio_remove_rmap(), let's rater move the mapcount sanity checks after the mapcount vs. refcount stabilization phase. With this fix, a simple reproducer is happy. While at it, convert the two VM_WARN_ON_ONCE() we are moving to VM_WARN_ON_ONCE_FOLIO(). Link: https://lkml.kernel.org/r/20250415095007.569836-1-david@redhat.com Fixes: 1da190f4d0a6 ("mm: Copy-on-Write (COW) reuse support for PTE-mapped THP") Signed-off-by: David Hildenbrand <david@redhat.com> Reported-by: syzbot+5e8feb543ca8e12e0ede@syzkaller.appspotmail.com Closes: https://lkml.kernel.org/r/67fab4fe.050a0220.2c5fcf.0011.GAE@google.com Reviewed-by: Oscar Salvador <osalvador@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-04-17mm, hugetlb: increment the number of pages to be reset on HVOOscar Salvador
commit 4eeec8c89a0c ("mm: move hugetlb specific things in folio to page[3]") shifted hugetlb specific stuff, and now mapping overlaps _hugetlb_cgroup field. Upon restoring the vmemmap for HVO, only the first two tail pages are reset, and this causes the check in free_tail_page_prepare() to fail as it finds an unexpected mapping value in some tails. Increment the number of pages to be reset to 4 (head + 3 tail pages) Link: https://lkml.kernel.org/r/20250415111859.376302-1-osalvador@suse.de Fixes: 4eeec8c89a0c ("mm: move hugetlb specific things in folio to page[3]") Signed-off-by: Oscar Salvador <osalvador@suse.de> Suggested-by: David Hildenbrand <david@redhat.com> Reviewed-by: David Hildenbrand <david@redhat.com> Reviewed-by: Muchun Song <muchun.song@linux.dev> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-04-17mm/gup: fix wrongly calculated returned value in fault_in_safe_writeable()Baoquan He
Not like fault_in_readable() or fault_in_writeable(), in fault_in_safe_writeable() local variable 'start' is increased page by page to loop till the whole address range is handled. However, it mistakenly calculates the size of the handled range with 'uaddr - start'. Fix it here. Andreas said: : In gfs2, fault_in_iov_iter_writeable() is used in : gfs2_file_direct_read() and gfs2_file_read_iter(), so this potentially : affects buffered as well as direct reads. This bug could cause those : gfs2 functions to spin in a loop. Link: https://lkml.kernel.org/r/20250410035717.473207-1-bhe@redhat.com Link: https://lkml.kernel.org/r/20250410035717.473207-2-bhe@redhat.com Signed-off-by: Baoquan He <bhe@redhat.com> Fixes: fe673d3f5bf1 ("mm: gup: make fault_in_safe_writeable() use fixup_user_fault()") Reviewed-by: Oscar Salvador <osalvador@suse.de> Acked-by: David Hildenbrand <david@redhat.com> Cc: Andreas Gruenbacher <agruenba@redhat.com> Cc: Yanjun.Zhu <yanjun.zhu@linux.dev> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-04-17mm: memcontrol: fix swap counter leak from offline cgroupMuchun Song
commit 73f839b6d2ed addressed an issue regarding the swap counter leak that occurred from an offline cgroup. However, commit 89ce924f0bd4 modified the parameter from @swap_memcg to @memcg (presumably this alteration was introduced while resolving conflicts). Fix this problem by reverting this minor change. Link: https://lkml.kernel.org/r/20250410081812.10073-1-songmuchun@bytedance.com Fixes: 89ce924f0bd4 ("mm: memcontrol: move memsw charge callbacks to v1") Signed-off-by: Muchun Song <songmuchun@bytedance.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Shakeel Butt <shakeel.butt@linux.dev> Acked-by: Roman Gushchin <roman.gushchin@linux.dev> Cc: Michal Hocko <mhocko@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-04-17mm/page_alloc: fix deadlock on cpu_hotplug_lock in __accept_page()Kirill A. Shutemov
When the last page in the zone is accepted, __accept_page() calls static_branch_dec(). This function takes cpu_hotplug_lock, which can lead to a deadlock if the allocation occurs during CPU bringup path as _cpu_up() also takes the lock. To prevent this deadlock, defer static_branch_dec() to a workqueue. Call static_branch_dec() only when the workqueue is not yet initialized. Workqueues are initialized before CPU bring up, so this will not conflict with the first scenario. Link: https://lkml.kernel.org/r/20250329171030.3942298-1-kirill.shutemov@linux.intel.com Fixes: 55ad43e8ba0f ("mm: add a helper to accept page") Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Reported-by: Srikanth Aithal <sraithal@amd.com> Tested-by: Srikanth Aithal <sraithal@amd.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Ashish Kalra <ashish.kalra@amd.com> Cc: David Hildenbrand <david@redhat.com> Cc: "Edgecombe, Rick P" <rick.p.edgecombe@intel.com> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: "Mike Rapoport (IBM)" <rppt@kernel.org> Cc: Thomas Lendacky <thomas.lendacky@amd.com> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-04-17Merge tag 'slab-for-6.15-rc2' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/vbabka/slab Pull slab fix from Vlastimil Babka: - Stable fix adding zero initialization of slab->obj_ext to prevent crashes with allocation profiling (Suren Baghdasaryan) * tag 'slab-for-6.15-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/vbabka/slab: slab: ensure slab->obj_exts is clear in a newly allocated slab page
2025-04-15kasan: Add strscpy() test to trigger tag fault on arm64Vincenzo Frascino
When we invoke strscpy() with a maximum size of N bytes, it assumes that: - It can always read N bytes from the source. - It always write N bytes (zero-padded) to the destination. On aarch64 with Memory Tagging Extension enabled if we pass an N that is bigger then the source buffer, it would previously trigger an MTE fault. Implement a KASAN KUnit test that triggers the issue with the previous implementation of read_word_at_a_time() on aarch64 with MTE enabled. Cc: Will Deacon <will@kernel.org> Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Co-developed-by: Peter Collingbourne <pcc@google.com> Signed-off-by: Peter Collingbourne <pcc@google.com> Reviewed-by: Andrey Konovalov <andreyknvl@gmail.com> Link: https://linux-review.googlesource.com/id/If88e396b9e7c058c1a4b5a252274120e77b1898a Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Link: https://lore.kernel.org/r/20250403000703.2584581-3-pcc@google.com Signed-off-by: Kees Cook <kees@kernel.org>
2025-04-14slab: ensure slab->obj_exts is clear in a newly allocated slab pageSuren Baghdasaryan
ktest recently reported crashes while running several buffered io tests with __alloc_tagging_slab_alloc_hook() at the top of the crash call stack. The signature indicates an invalid address dereference with low bits of slab->obj_exts being set. The bits were outside of the range used by page_memcg_data_flags and objext_flags and hence were not masked out by slab_obj_exts() when obtaining the pointer stored in slab->obj_exts. The typical crash log looks like this: 00510 Unable to handle kernel NULL pointer dereference at virtual address 0000000000000010 00510 Mem abort info: 00510 ESR = 0x0000000096000045 00510 EC = 0x25: DABT (current EL), IL = 32 bits 00510 SET = 0, FnV = 0 00510 EA = 0, S1PTW = 0 00510 FSC = 0x05: level 1 translation fault 00510 Data abort info: 00510 ISV = 0, ISS = 0x00000045, ISS2 = 0x00000000 00510 CM = 0, WnR = 1, TnD = 0, TagAccess = 0 00510 GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0 00510 user pgtable: 4k pages, 39-bit VAs, pgdp=0000000104175000 00510 [0000000000000010] pgd=0000000000000000, p4d=0000000000000000, pud=0000000000000000 00510 Internal error: Oops: 0000000096000045 [#1] SMP 00510 Modules linked in: 00510 CPU: 10 UID: 0 PID: 7692 Comm: cat Not tainted 6.15.0-rc1-ktest-g189e17946605 #19327 NONE 00510 Hardware name: linux,dummy-virt (DT) 00510 pstate: 20001005 (nzCv daif -PAN -UAO -TCO -DIT +SSBS BTYPE=--) 00510 pc : __alloc_tagging_slab_alloc_hook+0xe0/0x190 00510 lr : __kmalloc_noprof+0x150/0x310 00510 sp : ffffff80c87df6c0 00510 x29: ffffff80c87df6c0 x28: 000000000013d1ff x27: 000000000013d200 00510 x26: ffffff80c87df9e0 x25: 0000000000000000 x24: 0000000000000001 00510 x23: ffffffc08041953c x22: 000000000000004c x21: ffffff80c0002180 00510 x20: fffffffec3120840 x19: ffffff80c4821000 x18: 0000000000000000 00510 x17: fffffffec3d02f00 x16: fffffffec3d02e00 x15: fffffffec3d00700 00510 x14: fffffffec3d00600 x13: 0000000000000200 x12: 0000000000000006 00510 x11: ffffffc080bb86c0 x10: 0000000000000000 x9 : ffffffc080201e58 00510 x8 : ffffff80c4821060 x7 : 0000000000000000 x6 : 0000000055555556 00510 x5 : 0000000000000001 x4 : 0000000000000010 x3 : 0000000000000060 00510 x2 : 0000000000000000 x1 : ffffffc080f50cf8 x0 : ffffff80d801d000 00510 Call trace: 00510 __alloc_tagging_slab_alloc_hook+0xe0/0x190 (P) 00510 __kmalloc_noprof+0x150/0x310 00510 __bch2_folio_create+0x5c/0xf8 00510 bch2_folio_create+0x2c/0x40 00510 bch2_readahead+0xc0/0x460 00510 read_pages+0x7c/0x230 00510 page_cache_ra_order+0x244/0x3a8 00510 page_cache_async_ra+0x124/0x170 00510 filemap_readahead.isra.0+0x58/0xa0 00510 filemap_get_pages+0x454/0x7b0 00510 filemap_read+0xdc/0x418 00510 bch2_read_iter+0x100/0x1b0 00510 vfs_read+0x214/0x300 00510 ksys_read+0x6c/0x108 00510 __arm64_sys_read+0x20/0x30 00510 invoke_syscall.constprop.0+0x54/0xe8 00510 do_el0_svc+0x44/0xc8 00510 el0_svc+0x18/0x58 00510 el0t_64_sync_handler+0x104/0x130 00510 el0t_64_sync+0x154/0x158 00510 Code: d5384100 f9401c01 b9401aa3 b40002e1 (f8227881) 00510 ---[ end trace 0000000000000000 ]--- 00510 Kernel panic - not syncing: Oops: Fatal exception 00510 SMP: stopping secondary CPUs 00510 Kernel Offset: disabled 00510 CPU features: 0x0000,000000e0,00000410,8240500b 00510 Memory Limit: none Investigation indicates that these bits are already set when we allocate slab page and are not zeroed out after allocation. We are not yet sure why these crashes start happening only recently but regardless of the reason, not initializing a field that gets used later is wrong. Fix it by initializing slab->obj_exts during slab page allocation. Fixes: 21c690a349ba ("mm: introduce slabobj_ext to support slab object extensions") Reported-by: Kent Overstreet <kent.overstreet@linux.dev> Tested-by: Kent Overstreet <kent.overstreet@linux.dev> Signed-off-by: Suren Baghdasaryan <surenb@google.com> Acked-by: Kent Overstreet <kent.overstreet@linux.dev> Cc: stable@vger.kernel.org Link: https://patch.msgid.link/20250411155737.1360746-1-surenb@google.com Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
2025-04-11mm: fix apply_to_existing_page_range()Kirill A. Shutemov
In the case of apply_to_existing_page_range(), apply_to_pte_range() is reached with 'create' set to false. When !create, the loop over the PTE page table is broken. apply_to_pte_range() will only move to the next PTE entry if 'create' is true or if the current entry is not pte_none(). This means that the user of apply_to_existing_page_range() will not have 'fn' called for any entries after the first pte_none() in the PTE page table. Fix the loop logic in apply_to_pte_range(). There are no known runtime issues from this, but the fix is trivial enough for stable@ even without a known buggy user. Link: https://lkml.kernel.org/r/20250409094043.1629234-1-kirill.shutemov@linux.intel.com Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Fixes: be1db4753ee6 ("mm/memory.c: add apply_to_existing_page_range() helper") Cc: Daniel Axtens <dja@axtens.net> Cc: David Hildenbrand <david@redhat.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-04-11mm: (un)track_pfn_copy() fix + doc improvementsDavid Hildenbrand
We got a late smatch warning and some additional review feedback. smatch warnings: mm/memory.c:1428 copy_page_range() error: uninitialized symbol 'pfn'. We actually use the pfn only when it is properly initialized; however, we may pass an uninitialized value to a function -- although it will not use it that likely still is UB in C. So let's just fix it by always initializing pfn in the caller of track_pfn_copy(), and improving the documentation of track_pfn_copy(). While at it, clarify the doc of untrack_pfn_copy(), that internal checks make sure if we actually have to untrack anything. Link: https://lkml.kernel.org/r/20250408085950.976103-1-david@redhat.com Fixes: dc84bc2aba85 ("x86/mm/pat: Fix VM_PAT handling when fork() fails in copy_page_range()") Signed-off-by: David Hildenbrand <david@redhat.com> Reported-by: kernel test robot <lkp@intel.com> Reported-by: Dan Carpenter <error27@gmail.com> Closes: https://lore.kernel.org/r/202503270941.IFILyNCX-lkp@intel.com/ Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Acked-by: Ingo Molnar <mingo@kernel.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Borislav Petkov <bp@alien8.de> Cc: Rik van Riel <riel@surriel.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-04-11mm: fix filemap_get_folios_contig returning batches of identical foliosVishal Moola (Oracle)
filemap_get_folios_contig() is supposed to return distinct folios found within [start, end]. Large folios in the Xarray become multi-index entries. xas_next() can iterate through the sub-indexes before finding a sibling entry and breaking out of the loop. This can result in a returned folio_batch containing an indeterminate number of duplicate folios, which forces the callers to skeptically handle the returned batch. This is inefficient and incurs a large maintenance overhead. We can fix this by calling xas_advance() after we have successfully adding a folio to the batch to ensure our Xarray is positioned such that it will correctly find the next folio - similar to filemap_get_read_batch(). Link: https://lkml.kernel.org/r/Z-8s1-kiIDkzgRbc@fedora Fixes: 35b471467f88 ("filemap: add filemap_get_folios_contig()") Signed-off-by: Vishal Moola (Oracle) <vishal.moola@gmail.com> Reported-by: Qu Wenruo <quwenruo.btrfs@gmx.com> Closes: https://lkml.kernel.org/r/b714e4de-2583-4035-b829-72cfb5eb6fc6@gmx.com Tested-by: Qu Wenruo <quwenruo.btrfs@gmx.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Vivek Kasireddy <vivek.kasireddy@intel.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-04-11mm/hugetlb: add a line break at the end of the format stringwangxuewen
Missing line break at the end of the format string. Link: https://lkml.kernel.org/r/20250407103017.2979821-1-18810879172@163.com Signed-off-by: wangxuewen <wangxuewen@kylinos.cn> Cc: Muchun Song <muchun.song@linux.dev> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-04-11mm/hugetlb: fix set_max_huge_pages() when there are surplus pagesJinjiang Tu
In set_max_huge_pages(), min_count is computed taking into account surplus huge pages, which might lead in some cases to not be able to free huge pages and end up accounting them as surplus instead. One way to solve it is to subtract surplus_huge_pages directly, but we cannot do it blindly because there might be surplus pages that are also free pages, which might happen when we fail to restore the vmemmap for optimized hvo pages. So we could be subtracting the same page twice. In order to work this around, let us first compute the number of free persistent pages, and use that along with surplus pages to compute min_count. Steps to reproduce: 1) create 5 hugetlb folios in Node0 2) run a program to use all the hugetlb folios 3) echo 0 > nr_hugepages for Node0 to free the hugetlb folios. Thus the 5 hugetlb folios in Node0 are accounted as surplus. 4) create 5 hugetlb folios in Node1 5) echo 0 > nr_hugepages for Node1 to free the hugetlb folios The result: Node0 Node1 Total 5 5 Free 0 5 Surp 5 5 The result with this patch: Node0 Node1 Total 5 0 Free 0 0 Surp 5 0 Link: https://lkml.kernel.org/r/20250409055957.3774471-1-tujinjiang@huawei.com Link: https://lkml.kernel.org/r/20250407124706.2688092-1-tujinjiang@huawei.com Fixes: 9a30523066cd ("hugetlb: add per node hstate attributes") Signed-off-by: Jinjiang Tu <tujinjiang@huawei.com> Acked-by: Oscar Salvador <osalvador@suse.de> Cc: David Hildenbrand <david@redhat.com> Cc: Kefeng Wang <wangkefeng.wang@huawei.com> Cc: Muchun Song <muchun.song@linux.dev> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-04-11mm/cma: report base address of single range correctlyFrank van der Linden
The cma_declare_contiguous_nid code was refactored by commit c009da4258f9 ("mm, cma: support multiple contiguous ranges, if requested"), so that it could use an internal function to attempt a single range area first, and then try a multi-range one. However, that meant that the actual base address used for the !fixed case (base == 0) wasn't available one level up to be printed in the informational message, and it would always end up printing a base address of 0 in the boot message. Make the internal function take a phys_addr_t pointer to the base address, so that the value is available to the caller. [fvdl@google.com: v2] Link: https://lkml.kernel.org/r/20250408164000.3215690-1-fvdl@google.com Link: https://lkml.kernel.org/r/20250407165435.2567898-1-fvdl@google.com Fixes: c009da4258f9 ("mm, cma: support multiple contiguous ranges, if requested") Signed-off-by: Frank van der Linden <fvdl@google.com> Reported-by: Geert Uytterhoeven <geert@linux-m68k.org> Closes: https://lore.kernel.org/linux-mm/CAMuHMdVWviQ7O9yBFE3f=ev0eVb1CnsQvR6SKtEROBbM6z7g3w@mail.gmail.com/ Tested-by: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Muchun Song <muchun.song@linux.dev> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-04-11mm: page_alloc: speed up fallbacks in rmqueue_bulk()Johannes Weiner
The test robot identified c2f6ea38fc1b ("mm: page_alloc: don't steal single pages from biggest buddy") as the root cause of a 56.4% regression in vm-scalability::lru-file-mmap-read. Carlos reports an earlier patch, c0cd6f557b90 ("mm: page_alloc: fix freelist movement during block conversion"), as the root cause for a regression in worst-case zone->lock+irqoff hold times. Both of these patches modify the page allocator's fallback path to be less greedy in an effort to stave off fragmentation. The flip side of this is that fallbacks are also less productive each time around, which means the fallback search can run much more frequently. Carlos' traces point to rmqueue_bulk() specifically, which tries to refill the percpu cache by allocating a large batch of pages in a loop. It highlights how once the native freelists are exhausted, the fallback code first scans orders top-down for whole blocks to claim, then falls back to a bottom-up search for the smallest buddy to steal. For the next batch page, it goes through the same thing again. This can be made more efficient. Since rmqueue_bulk() holds the zone->lock over the entire batch, the freelists are not subject to outside changes; when the search for a block to claim has already failed, there is no point in trying again for the next page. Modify __rmqueue() to remember the last successful fallback mode, and restart directly from there on the next rmqueue_bulk() iteration. Oliver confirms that this improves beyond the regression that the test robot reported against c2f6ea38fc1b: commit: f3b92176f4 ("tools/selftests: add guard region test for /proc/$pid/pagemap") c2f6ea38fc ("mm: page_alloc: don't steal single pages from biggest buddy") acc4d5ff0b ("Merge tag 'net-6.15-rc0' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net") 2c847f27c3 ("mm: page_alloc: speed up fallbacks in rmqueue_bulk()") <--- your patch f3b92176f4f7100f c2f6ea38fc1b640aa7a2e155cc1 acc4d5ff0b61eb1715c498b6536 2c847f27c37da65a93d23c237c5 ---------------- --------------------------- --------------------------- --------------------------- %stddev %change %stddev %change %stddev %change %stddev \ | \ | \ | \ 25525364 ± 3% -56.4% 11135467 -57.8% 10779336 +31.6% 33581409 vm-scalability.throughput Carlos confirms that worst-case times are almost fully recovered compared to before the earlier culprit patch: 2dd482ba627d (before freelist hygiene): 1ms c0cd6f557b90 (after freelist hygiene): 90ms next-20250319 (steal smallest buddy): 280ms this patch : 8ms [jackmanb@google.com: comment updates] Link: https://lkml.kernel.org/r/D92AC0P9594X.3BML64MUKTF8Z@google.com [hannes@cmpxchg.org: reset rmqueue_mode in rmqueue_buddy() error loop, per Yunsheng Lin] Link: https://lkml.kernel.org/r/20250409140023.GA2313@cmpxchg.org Link: https://lkml.kernel.org/r/20250407180154.63348-1-hannes@cmpxchg.org Fixes: c0cd6f557b90 ("mm: page_alloc: fix freelist movement during block conversion") Fixes: c2f6ea38fc1b ("mm: page_alloc: don't steal single pages from biggest buddy") Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: Brendan Jackman <jackmanb@google.com> Reported-by: kernel test robot <oliver.sang@intel.com> Reported-by: Carlos Song <carlos.song@nxp.com> Tested-by: Carlos Song <carlos.song@nxp.com> Tested-by: kernel test robot <oliver.sang@intel.com> Closes: https://lore.kernel.org/oe-lkp/202503271547.fc08b188-lkp@intel.com Reviewed-by: Brendan Jackman <jackmanb@google.com> Tested-by: Shivank Garg <shivankg@amd.com> Acked-by: Zi Yan <ziy@nvidia.com> Reviewed-by: Vlastimil Babka <vbabka@suse.cz> Cc: <stable@vger.kernel.org> [6.10+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-04-11mm/kasan: add module decriptionArnd Bergmann
Modules without a description now cause a warning: WARNING: modpost: missing MODULE_DESCRIPTION() in mm/kasan/kasan_test.o [akpm@linux-foundation.org: update description text, per Andrey] Link: https://lkml.kernel.org/r/20250324173242.1501003-9-arnd@kernel.org Fixes: 6c6c1fc09de3 ("modpost: require a MODULE_DESCRIPTION()") Signed-off-by: Arnd Bergmann <arnd@arndb.de> Reviewed-by: Andrey Konovalov <andreyknvl@gmail.com> Cc: Alexander Potapenko <glider@google.com> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Cc: Dmitriy Vyukov <dvyukov@google.com> Cc: Jann Horn <jannh@google.com> Cc: Jeff Johnson <jeff.johnson@oss.qualcomm.com> Cc: Macro Elver <elver@google.com> Cc: Masahiro Yamada <masahiroy@kernel.org> Cc: Nihar Chaithanya <niharchaithanya@gmail.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Sabyrzhan Tasbolatov <snovitoll@gmail.com> Cc: Stehen Rothwell <sfr@canb.auug.org.au> Cc: Vincenzo Frascino <vincenzo.frascino@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-04-11mm/vma: add give_up_on_oom option on modify/merge, use in uffd releaseLorenzo Stoakes
Currently, if a VMA merge fails due to an OOM condition arising on commit merge or a failure to duplicate anon_vma's, we report this so the caller can handle it. However there are cases where the caller is only ostensibly trying a merge, and doesn't mind if it fails due to this condition. Since we do not want to introduce an implicit assumption that we only actually modify VMAs after OOM conditions might arise, add a 'give up on oom' option and make an explicit contract that, should this flag be set, we absolutely will not modify any VMAs should OOM arise and just bail out. Since it'd be very unusual for a user to try to vma_modify() with this flag set but be specifying a range within a VMA which ends up being split (which can fail due to rlimit issues, not only OOM), we add a debug warning for this condition. The motivating reason for this is uffd release - syzkaller (and Pedro Falcato's VERY astute analysis) found a way in which an injected fault on allocation, triggering an OOM condition on commit merge, would result in uffd code becoming confused and treating an error value as if it were a VMA pointer. To avoid this, we make use of this new VMG flag to ensure that this never occurs, utilising the fact that, should we be clearing entire VMAs, we do not wish an OOM event to be reported to us. Many thanks to Pedro Falcato for his excellent analysis and Jann Horn for his insightful and intelligent analysis of the situation, both of whom were instrumental in this fix. Link: https://lkml.kernel.org/r/20250321100937.46634-1-lorenzo.stoakes@oracle.com Reported-by: syzbot+20ed41006cf9d842c2b5@syzkaller.appspotmail.com Closes: https://lore.kernel.org/all/67dc67f0.050a0220.25ae54.001e.GAE@google.com/ Fixes: 47b16d0462a4 ("mm: abort vma_modify() on merge out of memory failure") Signed-off-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Suggested-by: Pedro Falcato <pfalcato@suse.de> Suggested-by: Jann Horn <jannh@google.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-04-11mm/hugetlb: fix nid mismatch in alloc_surplus_hugetlb_folio()Liu Shixin
It's wrong to use nid directly since the nid may be changed in allocation. Use folio_nid() to obtain the nid of folio instead. Fix: 2273dea6b1e1 ("mm/hugetlb: update nr_huge_pages and surplus_huge_pages together") Link: https://lkml.kernel.org/r/20250403064138.2867929-1-liushixin2@huawei.com Signed-off-by: Liu Shixin <liushixin2@huawei.com> Acked-by: Oscar Salvador <osalvador@suse.de> Cc: David Hildenbrand <david@redhat.com> Cc: Kefeng Wang <wangkefeng.wang@huawei.com> Cc: Muchun Song <muchun.song@linux.dev> Cc: Nanyong Sun <sunnanyong@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-04-11mm/page_alloc: avoid second trylock of zone->lockAlexei Starovoitov
spin_trylock followed by spin_lock will cause extra write cache access. If the lock is contended it may cause unnecessary cache line bouncing and will execute redundant irq restore/save pair. Therefore, check alloc/fpi_flags first and use spin_trylock or spin_lock. Link: https://lkml.kernel.org/r/20250331002809.94758-1-alexei.starovoitov@gmail.com Fixes: 97769a53f117 ("mm, bpf: Introduce try_alloc_pages() for opportunistic page allocation") Signed-off-by: Alexei Starovoitov <ast@kernel.org> Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Reviewed-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Acked-by: Michal Hocko <mhocko@suse.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Reviewed-by: Harry Yoo <harry.yoo@oracle.com> Reviewed-by: Shakeel Butt <shakeel.butt@linux.dev> Cc: Andrii Nakryiko <andrii@kernel.org> Cc: Daniel Borkman <daniel@iogearbox.net> Cc: Martin KaFai Lau <martin.lau@kernel.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-04-11mm/compaction: fix bug in hugetlb handling pathwayVishal Moola (Oracle)
The compaction code doesn't take references on pages until we're certain we should attempt to handle it. In the hugetlb case, isolate_or_dissolve_huge_page() may return -EBUSY without taking a reference to the folio associated with our pfn. If our folio's refcount drops to 0, compound_nr() becomes unpredictable, making low_pfn and nr_scanned unreliable. The user-visible effect is minimal - this should rarely happen (if ever). Fix this by storing the folio statistics earlier on the stack (just like the THP and Buddy cases). Also revert commit 66fe1cf7f581 ("mm: compaction: use helper compound_nr in isolate_migratepages_block") to make backporting easier. Link: https://lkml.kernel.org/r/20250401021025.637333-1-vishal.moola@gmail.com Fixes: 369fa227c219 ("mm: make alloc_contig_range handle free hugetlb pages") Signed-off-by: Vishal Moola (Oracle) <vishal.moola@gmail.com> Acked-by: Oscar Salvador <osalvador@suse.de> Reviewed-by: Zi Yan <ziy@nvidia.com> Cc: Miaohe Lin <linmiaohe@huawei.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-04-11locking/local_lock, mm: replace localtry_ helpers with local_trylock_t typeAlexei Starovoitov
Partially revert commit 0aaddfb06882 ("locking/local_lock: Introduce localtry_lock_t"). Remove localtry_*() helpers, since localtry_lock() name might be misinterpreted as "try lock". Introduce local_trylock[_irqsave]() helpers that only work with newly introduced local_trylock_t type. Note that attempt to use local_trylock[_irqsave]() with local_lock_t will cause compilation failure. Usage and behavior in !PREEMPT_RT: local_lock_t lock; // sizeof(lock) == 0 local_lock(&lock); // preempt disable local_lock_irqsave(&lock, ...); // irq save if (local_trylock_irqsave(&lock, ...)) // compilation error local_trylock_t lock; // sizeof(lock) == 4 local_lock(&lock); // preempt disable, acquired = 1 local_lock_irqsave(&lock, ...); // irq save, acquired = 1 if (local_trylock(&lock)) // if (!acquired) preempt disable, acquired = 1 if (local_trylock_irqsave(&lock, ...)) // if (!acquired) irq save, acquired = 1 The existing local_lock_*() macros can be used either with local_lock_t or local_trylock_t. With local_trylock_t they set acquired = 1 while local_unlock_*() clears it. In !PREEMPT_RT local_lock_irqsave(local_lock_t *) disables interrupts to protect critical section, but it doesn't prevent NMI, so the fully reentrant code cannot use local_lock_irqsave(local_lock_t *) for exclusive access. The local_lock_irqsave(local_trylock_t *) helper disables interrupts and sets acquired=1, so local_trylock_irqsave(local_trylock_t *) from NMI attempting to acquire the same lock will return false. In PREEMPT_RT local_lock_irqsave() maps to preemptible spin_lock(). Map local_trylock_irqsave() to preemptible spin_trylock(). When in hard IRQ or NMI return false right away, since spin_trylock() is not safe due to explicit locking in the underneath rt_spin_trylock() implementation. Removing this explicit locking and attempting only "trylock" is undesired due to PI implications. The local_trylock() without _irqsave can be used to avoid the cost of disabling/enabling interrupts by only disabling preemption, so local_trylock() in an interrupt attempting to acquire the same lock will return false. Note there is no need to use local_inc for acquired variable, since it's a percpu variable with strict nesting scopes. Note that guard(local_lock)(&lock) works only for "local_lock_t lock". The patch also makes sure that local_lock_release(l) is called before WRITE_ONCE(l->acquired, 0). Though IRQs are disabled at this point the local_trylock() from NMI will succeed and local_lock_acquire(l) will warn. Link: https://lkml.kernel.org/r/20250403025514.41186-1-alexei.starovoitov@gmail.com Fixes: 0aaddfb06882 ("locking/local_lock: Introduce localtry_lock_t") Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Reviewed-by: Shakeel Butt <shakeel.butt@linux.dev> Cc: Daniel Borkman <daniel@iogearbox.net> Cc: Linus Torvalds <torvalds@linuxfoundation.org> Cc: Martin KaFai Lau <martin.lau@kernel.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-04-07mm/memblock: repeat setting reserved region nid if array is doubledWei Yang
Commit 61167ad5fecd ("mm: pass nid to reserve_bootmem_region()") introduce a way to set nid to all reserved region. But there is a corner case it will leave some region with invalid nid. When memblock_set_node() doubles the array of memblock.reserved, it may lead to a new reserved region before current position. The new region will be left with an invalid node id. Repeat the process when detecting it. Fixes: 61167ad5fecd ("mm: pass nid to reserve_bootmem_region()") Signed-off-by: Wei Yang <richard.weiyang@gmail.com> CC: Mike Rapoport <rppt@kernel.org> CC: Yajun Deng <yajun.deng@linux.dev> CC: stable@vger.kernel.org Link: https://lore.kernel.org/r/20250318071948.23854-3-richard.weiyang@gmail.com Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
2025-04-07mm/memblock: pass size instead of end to memblock_set_node()Wei Yang
The second parameter of memblock_set_node() is size instead of end. Since it iterates from lower address to higher address, finally the node id is correct. But during the process, some of them are wrong. Pass size instead of end. Fixes: 61167ad5fecd ("mm: pass nid to reserve_bootmem_region()") Signed-off-by: Wei Yang <richard.weiyang@gmail.com> CC: Mike Rapoport <rppt@kernel.org> CC: Yajun Deng <yajun.deng@linux.dev> CC: stable@vger.kernel.org Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com> Link: https://lore.kernel.org/r/20250318071948.23854-2-richard.weiyang@gmail.com Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
2025-04-06Disable SLUB_TINY for build testingLinus Torvalds
... and don't error out so hard on missing module descriptions. Before commit 6c6c1fc09de3 ("modpost: require a MODULE_DESCRIPTION()") we used to warn about missing module descriptions, but only when building with extra warnigns (ie 'W=1'). After that commit the warning became an unconditional hard error. And it turns out not all modules have been converted despite the claims to the contrary. As reported by Damian Tometzki, the slub KUnit test didn't have a module description, and apparently nobody ever really noticed. The reason nobody noticed seems to be that the slub KUnit tests get disabled by SLUB_TINY, which also ends up disabling a lot of other code, both in tests and in slub itself. And so anybody doing full build tests didn't actually see this failre. So let's disable SLUB_TINY for build-only tests, since it clearly ends up limiting build coverage. Also turn the missing module descriptions error back into a warning, but let's keep it around for non-'W=1' builds. Reported-by: Damian Tometzki <damian@riscv-rocks.de> Link: https://lore.kernel.org/all/01070196099fd059-e8463438-7b1b-4ec8-816d-173874be9966-000000@eu-central-1.amazonses.com/ Cc: Masahiro Yamada <masahiroy@kernel.org> Cc: Jeff Johnson <jeff.johnson@oss.qualcomm.com> Fixes: 6c6c1fc09de3 ("modpost: require a MODULE_DESCRIPTION()") Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2025-04-05treewide: Switch/rename to timer_delete[_sync]()Thomas Gleixner
timer_delete[_sync]() replaces del_timer[_sync](). Convert the whole tree over and remove the historical wrapper inlines. Conversion was done with coccinelle plus manual fixups where necessary. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@kernel.org>
2025-04-03Merge tag 'mm-stable-2025-04-02-22-07' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Pull more MM updates from Andrew Morton: - The series "mm: fixes for fallouts from mem_init() cleanup" from Mike Rapoport fixes a couple of issues with the just-merged "arch, mm: reduce code duplication in mem_init()" series - The series "MAINTAINERS: add my isub-entries to MM part." from Mike Rapoport does some maintenance on MAINTAINERS - The series "remove tlb_remove_page_ptdesc()" from Qi Zheng does some cleanup work to the page mapping code - The series "mseal system mappings" from Jeff Xu permits sealing of "system mappings", such as vdso, vvar, vvar_vclock, vectors (arm compat-mode), sigpage (arm compat-mode) - Plus the usual shower of singleton patches * tag 'mm-stable-2025-04-02-22-07' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (31 commits) mseal sysmap: add arch-support txt mseal sysmap: enable s390 selftest: test system mappings are sealed mseal sysmap: update mseal.rst mseal sysmap: uprobe mapping mseal sysmap: enable arm64 mseal sysmap: enable x86-64 mseal sysmap: generic vdso vvar mapping selftests: x86: test_mremap_vdso: skip if vdso is msealed mseal sysmap: kernel config and header change mm: pgtable: remove tlb_remove_page_ptdesc() x86: pgtable: convert to use tlb_remove_ptdesc() riscv: pgtable: unconditionally use tlb_remove_ptdesc() mm: pgtable: convert some architectures to use tlb_remove_ptdesc() mm: pgtable: change pt parameter of tlb_remove_ptdesc() to struct ptdesc* mm: pgtable: make generic tlb_remove_table() use struct ptdesc microblaze/mm: put mm_cmdline_setup() in .init.text section mm/memory_hotplug: fix call folio_test_large with tail page in do_migrate_range MAINTAINERS: mm: add entry for secretmem MAINTAINERS: mm: add entry for numa memblocks and numa emulation ...
2025-04-03Merge tag 'mm-hotfixes-stable-2025-04-02-21-57' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Pull MM hotfixes from Andrew Morton: "Five hotfixes. Three are cc:stable and the remainder address post-6.14 issues or aren't considered necessary for -stable kernels. All patches are for MM" * tag 'mm-hotfixes-stable-2025-04-02-21-57' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: mm: zswap: fix crypto_free_acomp() deadlock in zswap_cpu_comp_dead() mm/hugetlb: move hugetlb_sysctl_init() to the __init section mm: page_isolation: avoid calling folio_hstate() without hugetlb_lock mm/hugetlb_vmemmap: fix memory loads ordering mm/userfaultfd: fix release hang over concurrent GUP
2025-04-02mm/page_alloc: Fix try_alloc_pagesAlexei Starovoitov
Fix an obvious bug. try_alloc_pages() should set_page_refcounted. [ Not so obvious: it was probably correct at the time it was written but was at some point then rebased on top of v6.14-rc1. And at that point there was a semantic conflict with commit efabfe1420f5 ("mm/page_alloc: move set_page_refcounted() to callers of get_page_from_freelist()") and became buggy. - Linus ] Fixes: 97769a53f117 ("mm, bpf: Introduce try_alloc_pages() for opportunistic page allocation") Signed-off-by: Alexei Starovoitov <ast@kernel.org> Reviewed-by: Shakeel Butt <shakeel.butt@linux.dev> Acked-by: Michal Hocko <mhocko@suse.com> Acked-by: Vlastimil BAbka <vbabka@suse.cz> Reviewed-by: Harry Yoo <harry.yoo@oracle.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2025-04-01Merge tag 'vfio-v6.15-rc1' of https://github.com/awilliam/linux-vfioLinus Torvalds
Pull VFIO updates from Alex Williamson: - Relax IGD support code to match display class device rather than specifically requiring a VGA device (Tomita Moeko) - Accelerate DMA mapping of device MMIO by iterating at PMD and PUD levels to take advantage of huge pfnmap support added in v6.12 (Alex Williamson) - Extend virtio vfio-pci variant driver to include migration support for block devices where enabled by the PF (Yishai Hadas) - Virtualize INTx PIN register for devices where the platform does not route legacy PCI interrupts for the device and the interrupt is reported as IRQ_NOTCONNECTED (Alex Williamson) * tag 'vfio-v6.15-rc1' of https://github.com/awilliam/linux-vfio: vfio/pci: Handle INTx IRQ_NOTCONNECTED vfio/virtio: Enable support for virtio-block live migration vfio/type1: Use mapping page mask for pfnmaps mm: Provide address mask in struct follow_pfnmap_args vfio/type1: Use consistent types for page counts vfio/type1: Use vfio_batch for vaddr_get_pfns() vfio/type1: Convert all vaddr_get_pfns() callers to use vfio_batch vfio/type1: Catch zero from pin_user_pages_remote() vfio/pci: match IGD devices in display controller class
2025-04-01mm/memory_hotplug: fix call folio_test_large with tail page in do_migrate_rangeJinjiang Tu
We triggered the below BUG: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x2 pfn:0x240402 head: order:9 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 flags: 0x1ffffe0000000040(head|node=1|zone=3|lastcpupid=0x1ffff) page_type: f4(hugetlb) page dumped because: VM_BUG_ON_PAGE(page->compound_head & 1) ------------[ cut here ]------------ kernel BUG at ./include/linux/page-flags.h:310! Internal error: Oops - BUG: 00000000f2000800 [#1] PREEMPT SMP Modules linked in: CPU: 7 UID: 0 PID: 166 Comm: sh Not tainted 6.14.0-rc7-dirty #374 Hardware name: QEMU QEMU Virtual Machine, BIOS 0.0.0 02/06/2015 pstate: 60000005 (nZCv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--) pc : const_folio_flags+0x3c/0x58 lr : const_folio_flags+0x3c/0x58 Call trace: const_folio_flags+0x3c/0x58 (P) do_migrate_range+0x164/0x720 offline_pages+0x63c/0x6fc memory_subsys_offline+0x190/0x1f4 device_offline+0xc0/0x13c state_store+0x90/0xd8 dev_attr_store+0x18/0x2c sysfs_kf_write+0x44/0x54 kernfs_fop_write_iter+0x120/0x1cc vfs_write+0x240/0x378 ksys_write+0x70/0x108 __arm64_sys_write+0x1c/0x28 invoke_syscall+0x48/0x10c el0_svc_common.constprop.0+0x40/0xe0 When allocating a hugetlb folio, between the folio is taken from buddy and prep_compound_page() is called, start_isolate_page_range() and do_migrate_range() is called. When do_migrate_range() scans the head page of the hugetlb folio, the compound_head field isn't set, so scans the tail page next. And at this time, the compound_head field of tail page is set, folio_test_large() is called by tail page, thus triggers VM_BUG_ON(). To fix it, get folio refcount before calling folio_test_large(). Link: https://lkml.kernel.org/r/20250324131750.1551884-1-tujinjiang@huawei.com Fixes: 8135d8926c08 ("mm: memory_hotplug: memory hotremove supports thp migration") Fixes: b62b51d2d159 ("mm: memory_hotplug: remove head variable in do_migrate_range()") Signed-off-by: Jinjiang Tu <tujinjiang@huawei.com> Acked-by: Oscar Salvador <osalvador@suse.de> Acked-by: David Hildenbrand <david@redhat.com> Cc: Kefeng Wang <wangkefeng.wang@huawei.com> Cc: Nanyong Sun <sunnanyong@huawei.com> Cc: Naoya Horiguchi <nao.horiguchi@gmail.com> Cc: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-04-01memblock: don't release high memory to page allocator when HIGHMEM is offMike Rapoport (Microsoft)
Nathan Chancellor reports the following crash on a MIPS system with CONFIG_HIGHMEM=n: Linux version 6.14.0-rc6-00359-g6faea3422e3b (nathan@ax162) (mips-linux-gcc (GCC) 14.2.0, GNU ld (GNU Binutils) 2.42) #1 SMP Fri Mar 21 08:12:02 MST 2025 earlycon: uart8250 at I/O port 0x3f8 (options '38400n8') printk: legacy bootconsole [uart8250] enabled Config serial console: console=ttyS0,38400n8r CPU0 revision is: 00019300 (MIPS 24Kc) FPU revision is: 00739300 MIPS: machine is mti,malta Software DMA cache coherency enabled Initial ramdisk at: 0x8fad0000 (5360128 bytes) OF: reserved mem: Reserved memory: No reserved-memory node in the DT Primary instruction cache 2kB, VIPT, 2-way, linesize 16 bytes. Primary data cache 2kB, 2-way, VIPT, no aliases, linesize 16 bytes Zone ranges: DMA [mem 0x0000000000000000-0x0000000000ffffff] Normal [mem 0x0000000001000000-0x000000001fffffff] Movable zone start for each node Early memory node ranges node 0: [mem 0x0000000000000000-0x000000000fffffff] node 0: [mem 0x0000000090000000-0x000000009fffffff] Initmem setup node 0 [mem 0x0000000000000000-0x000000009fffffff] On node 0, zone Normal: 16384 pages in unavailable ranges random: crng init done percpu: Embedded 3 pages/cpu s18832 r8192 d22128 u49152 Kernel command line: rd_start=0xffffffff8fad0000 rd_size=5360128 console=ttyS0,38400n8r printk: log buffer data + meta data: 32768 + 102400 = 135168 bytes Dentry cache hash table entries: 65536 (order: 4, 262144 bytes, linear) Inode-cache hash table entries: 32768 (order: 3, 131072 bytes, linear) Writing ErrCtl register=00000000 Readback ErrCtl register=00000000 Built 1 zonelists, mobility grouping on. Total pages: 16384 mem auto-init: stack:all(zero), heap alloc:off, heap free:off Unhandled kernel unaligned access[#1]: CPU: 0 UID: 0 PID: 0 Comm: swapper Not tainted 6.14.0-rc6-00359-g6faea3422e3b #1 Hardware name: mti,malta $ 0 : 00000000 00000001 81cb0880 00129027 $ 4 : 00000001 0000000a 00000002 00129026 $ 8 : ffffdfff 80101e00 00000002 00000000 $12 : 81c9c224 81c63e68 00000002 00000000 $16 : 805b1e00 00025800 81cb0880 00000002 $20 : 00000000 81c63e64 0000000a 81f10000 $24 : 81c63e64 81c63e60 $28 : 81c60000 81c63de0 00000001 81cc9d20 Hi : 00000000 Lo : 00000000 epc : 814a227c __free_pages_ok+0x144/0x3c0 ra : 81cc9d20 memblock_free_all+0x1d4/0x27c Status: 10000002 KERNEL EXL Cause : 00800410 (ExcCode 04) BadVA : 00129026 PrId : 00019300 (MIPS 24Kc) Modules linked in: Process swapper (pid: 0, threadinfo=(ptrval), task=(ptrval), tls=00000000) Stack : 81f10000 805a9e00 81c80000 00000000 00000002 814aa240 000003ff 00000400 00000000 81f10000 81c9c224 00003b1f 81c80000 81c63e60 81ca0000 81c63e64 81f10000 0000000a 0000001f 81cc9d20 81f10000 81cc96d8 00000000 81c80000 81c9c224 81c63e60 81c63e64 00000000 81f10000 00024000 00028000 00025c00 90000000 a0000000 00000002 00000017 00000000 00000000 81f10000 81f10000 ... Call Trace: [<814a227c>] __free_pages_ok+0x144/0x3c0 [<81cc9d20>] memblock_free_all+0x1d4/0x27c [<81cc6764>] mm_core_init+0x100/0x138 [<81cb4ba4>] start_kernel+0x4a0/0x6e4 Code: 1080ffd5 02003825 2467ffff <8ce30000> 7c630500 1060ffd4 00000000 8ce30000 7c630180 The crash happens because commit 6faea3422e3b ("arch, mm: streamline HIGHMEM freeing") too eagerly frees high memory to the page allocator even when HIGHMEM is disabled. Make sure that when CONFIG_HIGHMEM=n the high memory is not released to the page allocator. Link: https://lore.kernel.org/all/20250323190647.GA1009914@ax162 Link: https://lkml.kernel.org/r/20250325114928.1791109-3-rppt@kernel.org Reported-by: Nathan Chancellor <nathan@kernel.org> Fixes: 6faea3422e3b ("arch, mm: streamline HIGHMEM freeing") Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org> Tested-by: Nathan Chancellor <nathan@kernel.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Betkov <bp@alien8.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jiaxun Yang <jiaxun.yang@flygoat.com> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: Thomas Gleinxer <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-04-01mm/mm_init: init holes in the end of the memory map for FLATMEMMike Rapoport (Microsoft)
Patch series "mm: fixes for fallouts from mem_init() cleanup". These are the fixes for fallouts from mem_init() cleanup reported by Nathan Chancellor and kbuild. The details are in the commit messages. This patch (of 2): Kernel test robot reports the following crash on 32-bit system with FLATMEM and DEBUG_VM_PGFLAGS enabled: [ 0.478822][ T0] kernel BUG at include/linux/page-flags.h:536! [ 0.479312][ T0] Oops: invalid opcode: 0000 [#1] PREEMPT SMP [ 0.479768][ T0] CPU: 0 UID: 0 PID: 0 Comm: swapper Not tainted 6.14.0-rc6-00357-g8268af309d07 #1 [ 0.480470][ T0] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.2-debian-1.16.2-1 04/01/2014 [ 0.481260][ T0] EIP: reserve_bootmem_region (include/linux/page-flags.h:536) [ 0.481683][ T0] Code: 5d c3 01 f1 89 c8 ba e1 38 f4 c3 e8 1e 37 8e fc 0f 0b b8 90 e2 62 c4 e8 e2 05 5e fc 01 f1 89 c8 ba be 85 f7 c3 e8 04 37 8e fc <0f> 0b b8 80 e2 62 c4 e8 c8 05 5e fc 55 89 e5 53 57 56 83 ec 10 89 [ 0.483177][ T0] EAX: 00000000 EBX: c425df50 ECX: 00000000 EDX: 00000000 [ 0.483712][ T0] ESI: 017ffc00 EDI: ffffffff EBP: c425df34 ESP: c425df2c [ 0.484248][ T0] DS: 007b ES: 007b FS: 00d8 GS: 0000 SS: 0068 EFLAGS: 00210046 [ 0.484846][ T0] CR0: 80050033 CR2: 00000000 CR3: 04b48000 CR4: 00000090 [ 0.485376][ T0] DR0: 00000000 DR1: 00000000 DR2: 00000000 DR3: 00000000 [ 0.485907][ T0] DR6: fffe0ff0 DR7: 00000400 [ 0.486253][ T0] Call Trace: [ 0.486494][ T0] ? __die_body (arch/x86/kernel/dumpstack.c:478) [ 0.486822][ T0] ? die (arch/x86/kernel/dumpstack.c:?) [ 0.487099][ T0] ? do_trap (arch/x86/kernel/traps.c:? arch/x86/kernel/traps.c:197) [ 0.487409][ T0] ? do_error_trap (arch/x86/kernel/traps.c:217) [ 0.487752][ T0] ? reserve_bootmem_region (include/linux/page-flags.h:536) [ 0.488153][ T0] ? exc_overflow (arch/x86/kernel/traps.c:301) [ 0.488490][ T0] ? handle_invalid_op (arch/x86/kernel/traps.c:254) [ 0.488869][ T0] ? reserve_bootmem_region (include/linux/page-flags.h:536) [ 0.489271][ T0] ? exc_invalid_op (arch/x86/kernel/traps.c:316) [ 0.489619][ T0] ? handle_exception (arch/x86/entry/entry_32.S:1055) [ 0.489996][ T0] ? exc_overflow (arch/x86/kernel/traps.c:301) [ 0.490332][ T0] ? reserve_bootmem_region (include/linux/page-flags.h:536) [ 0.490733][ T0] ? exc_overflow (arch/x86/kernel/traps.c:301) [ 0.491068][ T0] ? reserve_bootmem_region (include/linux/page-flags.h:536) [ 0.491470][ T0] memmap_init_reserved_pages (mm/memblock.c:2203) [ 0.491887][ T0] free_low_memory_core_early (mm/memblock.c:?) [ 0.492302][ T0] memblock_free_all (mm/memblock.c:2272 include/linux/atomic/atomic-arch-fallback.h:546 include/linux/atomic/atomic-long.h:123 include/linux/atomic/atomic-instrumented.h:3261 include/linux/mm.h:67 mm/memblock.c:2273) [ 0.492659][ T0] mem_init (arch/x86/mm/init_32.c:735) [ 0.492952][ T0] mm_core_init (mm/mm_init.c:2730) [ 0.493271][ T0] start_kernel (init/main.c:958) [ 0.493604][ T0] i386_start_kernel (arch/x86/kernel/head32.c:79) [ 0.493969][ T0] startup_32_smp (arch/x86/kernel/head_32.S:292) The crash happens because after commit 8268af309d07 ("arch, mm: set max_mapnr when allocating memory map for FLATMEM") max_mapnr is rounded up to MAX_ORDER_NR_PAGES and the pages in the end of the memory map are passing pfn_valid() check in reserve_bootmem_region(). Make sure that that pages in the end of the memory map are initialized, just like the pages in the end of the last section for SPARSEMEM. Link: https://lkml.kernel.org/r/20250325114928.1791109-1-rppt@kernel.org Link: https://lkml.kernel.org/r/20250325114928.1791109-2-rppt@kernel.org Fixes: 8268af309d07 ("arch, mm: set max_mapnr when allocating memory map for FLATMEM") Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org> Reported-by: kernel test robot <oliver.sang@intel.com> Closes: https://lore.kernel.org/oe-lkp/202503241424.d16223ec-lkp@intel.com Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Betkov <bp@alien8.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jiaxun Yang <jiaxun.yang@flygoat.com> Cc: Nathan Chancellor <nathan@kernel.org> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: Thomas Gleinxer <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-04-01mm/page_alloc: replace flag check with PageHWPoison() in check_new_page_bad()Ye Liu
This patch replaces the direct check for the __PG_HWPOISON flag with the PageHWPoison() macro, improving code readability and maintaining consistency with other parts of the memory management code. Link: https://lkml.kernel.org/r/20250320063346.489030-1-ye.liu@linux.dev Signed-off-by: Ye Liu <liuye@kylinos.cn> Reviewed-by: Sidhartha Kumar <sidhartha.kumar@oracle.com> Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-04-01mm/damon/core: simplify control flow in damon_register_ops()Taotao Chen
The function logic is not complex, so using goto is unnecessary. Replace it with a straightforward if-else to simplify control flow and improve readability. Link: https://lkml.kernel.org/r/Z9vxcPCw8tDsjKw1@OneApple Signed-off-by: Taotao Chen <chentaotao@didiglobal.com> Reviewed-by: SeongJae Park <sj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-04-01mm/kasan: use SLAB_NO_MERGE flag instead of an empty constructorHarry Yoo
Use SLAB_NO_MERGE flag to prevent merging instead of providing an empty constructor. Using an empty constructor in this manner is an abuse of slab interface. The SLAB_NO_MERGE flag should be used with caution, but in this case, it is acceptable as the cache is intended solely for debugging purposes. No functional changes intended. Link: https://lkml.kernel.org/r/20250318015926.1629748-1-harry.yoo@oracle.com Signed-off-by: Harry Yoo <harry.yoo@oracle.com> Reviewed-by: Alexander Potapenko <glider@google.com> Reviewed-by: Andrey Konovalov <andreyknvl@gmail.com> Acked-by: Andrey Ryabinin <ryabinin.a.a@gmail.com> Cc: Dmitriy Vyukov <dvyukov@google.com> Cc: Vincenzo Frascino <vincenzo.frascino@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-04-01mm: page_alloc: fix defrag_mode's retry & OOM pathJohannes Weiner
Brendan points out that defrag_mode doesn't properly clear ALLOC_NOFRAGMENT on its last-ditch attempt to allocate. But looking closer, the problem is actually more severe: it doesn't actually *check* whether it's already retried, and keeps looping. This means the OOM path is never taken, and the thread can loop indefinitely. This is verified with an intentional OOM test on defrag_mode=1, which results in the machine hanging. After this patch, it triggers the OOM kill reliably and recovers. Clear ALLOC_NOFRAGMENT properly, and only retry once. Link: https://lkml.kernel.org/r/20250401041231.GA2117727@cmpxchg.org Fixes: e3aa7df331bc ("mm: page_alloc: defrag_mode") Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Reported-by: Brendan Jackman <jackmanb@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-04-01mm/mremap: do not set vrm->vma NULL immediately prior to checking itLorenzo Stoakes
This seems rather unwise. If we cannot merge, extend, then we need to recall the original VMA to see if we need to uncharge. If we do need to, do so. Link: https://lkml.kernel.org/r/b2fb6b9c-376d-4e9b-905e-26d847fd3865@lucifer.local Fixes: d5c8aec0542e ("mm/mremap: initial refactor of move_vma()") Signed-off-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Reported-=by: "Lai, Yi" <yi1.lai@linux.intel.com> Closes: https://lore.kernel.org/linux-mm/Z+lcvEIHMLiKVR1i@ly-workstation/ Cc: Liam R. Howlett <Liam.Howlett@Oracle.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Harry Yoo <harry.yoo@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-04-01mm: zswap: fix crypto_free_acomp() deadlock in zswap_cpu_comp_dead()Yosry Ahmed
Currently, zswap_cpu_comp_dead() calls crypto_free_acomp() while holding the per-CPU acomp_ctx mutex. crypto_free_acomp() then holds scomp_lock (through crypto_exit_scomp_ops_async()). On the other hand, crypto_alloc_acomp_node() holds the scomp_lock (through crypto_scomp_init_tfm()), and then allocates memory. If the allocation results in reclaim, we may attempt to hold the per-CPU acomp_ctx mutex. The above dependencies can cause an ABBA deadlock. For example in the following scenario: (1) Task A running on CPU #1: crypto_alloc_acomp_node() Holds scomp_lock Enters reclaim Reads per_cpu_ptr(pool->acomp_ctx, 1) (2) Task A is descheduled (3) CPU #1 goes offline zswap_cpu_comp_dead(CPU #1) Holds per_cpu_ptr(pool->acomp_ctx, 1)) Calls crypto_free_acomp() Waits for scomp_lock (4) Task A running on CPU #2: Waits for per_cpu_ptr(pool->acomp_ctx, 1) // Read on CPU #1 DEADLOCK Since there is no requirement to call crypto_free_acomp() with the per-CPU acomp_ctx mutex held in zswap_cpu_comp_dead(), move it after the mutex is unlocked. Also move the acomp_request_free() and kfree() calls for consistency and to avoid any potential sublte locking dependencies in the future. With this, only setting acomp_ctx fields to NULL occurs with the mutex held. This is similar to how zswap_cpu_comp_prepare() only initializes acomp_ctx fields with the mutex held, after performing all allocations before holding the mutex. Opportunistically, move the NULL check on acomp_ctx so that it takes place before the mutex dereference. Link: https://lkml.kernel.org/r/20250226185625.2672936-1-yosry.ahmed@linux.dev Fixes: 12dcb0ef5406 ("mm: zswap: properly synchronize freeing resources during CPU hotunplug") Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Co-developed-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: Yosry Ahmed <yosry.ahmed@linux.dev> Reported-by: syzbot+1a517ccfcbc6a7ab0f82@syzkaller.appspotmail.com Closes: https://lore.kernel.org/all/67bcea51.050a0220.bbfd1.0096.GAE@google.com/ Acked-by: Herbert Xu <herbert@gondor.apana.org.au> Reviewed-by: Chengming Zhou <chengming.zhou@linux.dev> Reviewed-by: Nhat Pham <nphamcs@gmail.com> Tested-by: Nhat Pham <nphamcs@gmail.com> Cc: David S. Miller <davem@davemloft.net> Cc: Eric Biggers <ebiggers@kernel.org> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Chris Murphy <lists@colorremedies.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-04-01mm/hugetlb: move hugetlb_sysctl_init() to the __init sectionMarc Herbert
hugetlb_sysctl_init() is only invoked once by an __init function and is merely a wrapper around another __init function so there is not reason to keep it. Fixes the following warning when toning down some GCC inline options: WARNING: modpost: vmlinux: section mismatch in reference: hugetlb_sysctl_init+0x1b (section: .text) -> __register_sysctl_init (section: .init.text) Link: https://lkml.kernel.org/r/20250319060041.2737320-1-marc.herbert@linux.intel.com Signed-off-by: Marc Herbert <Marc.Herbert@linux.intel.com> Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com> Reviewed-by: Muchun Song <muchun.song@linux.dev> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-04-01mm: page_isolation: avoid calling folio_hstate() without hugetlb_lockLiu Shixin
I found a NULL pointer dereference as followed: BUG: kernel NULL pointer dereference, address: 0000000000000028 #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page PGD 0 P4D 0 Oops: Oops: 0000 [#1] SMP PTI CPU: 5 UID: 0 PID: 5964 Comm: sh Kdump: loaded Not tainted 6.13.0-dirty #20 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-1ubuntu1. RIP: 0010:has_unmovable_pages+0x184/0x360 ... Call Trace: <TASK> set_migratetype_isolate+0xd1/0x180 start_isolate_page_range+0xd2/0x170 alloc_contig_range_noprof+0x101/0x660 alloc_contig_pages_noprof+0x238/0x290 alloc_gigantic_folio.isra.0+0xb6/0x1f0 only_alloc_fresh_hugetlb_folio.isra.0+0xf/0x60 alloc_pool_huge_folio+0x80/0xf0 set_max_huge_pages+0x211/0x490 __nr_hugepages_store_common+0x5f/0xe0 nr_hugepages_store+0x77/0x80 kernfs_fop_write_iter+0x118/0x200 vfs_write+0x23c/0x3f0 ksys_write+0x62/0xe0 do_syscall_64+0x5b/0x170 entry_SYSCALL_64_after_hwframe+0x76/0x7e As has_unmovable_pages() call folio_hstate() without hugetlb_lock, there is a race to free the HugeTLB page between PageHuge() and folio_hstate(). There is no need to add hugetlb_lock here as the HugeTLB page can be freed in lot of places. So it's enough to unfold folio_hstate() and add a check to avoid NULL pointer dereference for hugepage_migration_supported(). Link: https://lkml.kernel.org/r/20250122061151.578768-1-liushixin2@huawei.com Fixes: 464c7ffbcb16 ("mm/hugetlb: filter out hugetlb pages if HUGEPAGE migration is not supported.") Signed-off-by: Liu Shixin <liushixin2@huawei.com> Acked-by: David Hildenbrand <david@redhat.com> Acked-by: Zi Yan <ziy@nvidia.com> Reviewed-by: Oscar Salvador <osalvador@suse.de> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Kefeng Wang <wangkefeng.wang@huawei.com> Cc: Kirill A. Shuemov <kirill.shutemov@linux.intel.com> Cc: Muchun Song <muchun.song@linux.dev> Cc: Nanyong Sun <sunnanyong@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-04-01Merge tag 'mm-stable-2025-03-30-16-52' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Pull MM updates from Andrew Morton: - The series "Enable strict percpu address space checks" from Uros Bizjak uses x86 named address space qualifiers to provide compile-time checking of percpu area accesses. This has caused a small amount of fallout - two or three issues were reported. In all cases the calling code was found to be incorrect. - The series "Some cleanup for memcg" from Chen Ridong implements some relatively monir cleanups for the memcontrol code. - The series "mm: fixes for device-exclusive entries (hmm)" from David Hildenbrand fixes a boatload of issues which David found then using device-exclusive PTE entries when THP is enabled. More work is needed, but this makes thins better - our own HMM selftests now succeed. - The series "mm: zswap: remove z3fold and zbud" from Yosry Ahmed remove the z3fold and zbud implementations. They have been deprecated for half a year and nobody has complained. - The series "mm: further simplify VMA merge operation" from Lorenzo Stoakes implements numerous simplifications in this area. No runtime effects are anticipated. - The series "mm/madvise: remove redundant mmap_lock operations from process_madvise()" from SeongJae Park rationalizes the locking in the madvise() implementation. Performance gains of 20-25% were observed in one MADV_DONTNEED microbenchmark. - The series "Tiny cleanup and improvements about SWAP code" from Baoquan He contains a number of touchups to issues which Baoquan noticed when working on the swap code. - The series "mm: kmemleak: Usability improvements" from Catalin Marinas implements a couple of improvements to the kmemleak user-visible output. - The series "mm/damon/paddr: fix large folios access and schemes handling" from Usama Arif provides a couple of fixes for DAMON's handling of large folios. - The series "mm/damon/core: fix wrong and/or useless damos_walk() behaviors" from SeongJae Park fixes a few issues with the accuracy of kdamond's walking of DAMON regions. - The series "expose mapping wrprotect, fix fb_defio use" from Lorenzo Stoakes changes the interaction between framebuffer deferred-io and core MM. No functional changes are anticipated - this is preparatory work for the future removal of page structure fields. - The series "mm/damon: add support for hugepage_size DAMOS filter" from Usama Arif adds a DAMOS filter which permits the filtering by huge page sizes. - The series "mm: permit guard regions for file-backed/shmem mappings" from Lorenzo Stoakes extends the guard region feature from its present "anon mappings only" state. The feature now covers shmem and file-backed mappings. - The series "mm: batched unmap lazyfree large folios during reclamation" from Barry Song cleans up and speeds up the unmapping for pte-mapped large folios. - The series "reimplement per-vma lock as a refcount" from Suren Baghdasaryan puts the vm_lock back into the vma. Our reasons for pulling it out were largely bogus and that change made the code more messy. This patchset provides small (0-10%) improvements on one microbenchmark. - The series "Docs/mm/damon: misc DAMOS filters documentation fixes and improves" from SeongJae Park does some maintenance work on the DAMON docs. - The series "hugetlb/CMA improvements for large systems" from Frank van der Linden addresses a pile of issues which have been observed when using CMA on large machines. - The series "mm/damon: introduce DAMOS filter type for unmapped pages" from SeongJae Park enables users of DMAON/DAMOS to filter my the page's mapped/unmapped status. - The series "zsmalloc/zram: there be preemption" from Sergey Senozhatsky teaches zram to run its compression and decompression operations preemptibly. - The series "selftests/mm: Some cleanups from trying to run them" from Brendan Jackman fixes a pile of unrelated issues which Brendan encountered while runnimg our selftests. - The series "fs/proc/task_mmu: add guard region bit to pagemap" from Lorenzo Stoakes permits userspace to use /proc/pid/pagemap to determine whether a particular page is a guard page. - The series "mm, swap: remove swap slot cache" from Kairui Song removes the swap slot cache from the allocation path - it simply wasn't being effective. - The series "mm: cleanups for device-exclusive entries (hmm)" from David Hildenbrand implements a number of unrelated cleanups in this code. - The series "mm: Rework generic PTDUMP configs" from Anshuman Khandual implements a number of preparatoty cleanups to the GENERIC_PTDUMP Kconfig logic. - The series "mm/damon: auto-tune aggregation interval" from SeongJae Park implements a feedback-driven automatic tuning feature for DAMON's aggregation interval tuning. - The series "Fix lazy mmu mode" from Ryan Roberts fixes some issues in powerpc, sparc and x86 lazy MMU implementations. Ryan did this in preparation for implementing lazy mmu mode for arm64 to optimize vmalloc. - The series "mm/page_alloc: Some clarifications for migratetype fallback" from Brendan Jackman reworks some commentary to make the code easier to follow. - The series "page_counter cleanup and size reduction" from Shakeel Butt cleans up the page_counter code and fixes a size increase which we accidentally added late last year. - The series "Add a command line option that enables control of how many threads should be used to allocate huge pages" from Thomas Prescher does that. It allows the careful operator to significantly reduce boot time by tuning the parallalization of huge page initialization. - The series "Fix calculations in trace_balance_dirty_pages() for cgwb" from Tang Yizhou fixes the tracing output from the dirty page balancing code. - The series "mm/damon: make allow filters after reject filters useful and intuitive" from SeongJae Park improves the handling of allow and reject filters. Behaviour is made more consistent and the documention is updated accordingly. - The series "Switch zswap to object read/write APIs" from Yosry Ahmed updates zswap to the new object read/write APIs and thus permits the removal of some legacy code from zpool and zsmalloc. - The series "Some trivial cleanups for shmem" from Baolin Wang does as it claims. - The series "fs/dax: Fix ZONE_DEVICE page reference counts" from Alistair Popple regularizes the weird ZONE_DEVICE page refcount handling in DAX, permittig the removal of a number of special-case checks. - The series "refactor mremap and fix bug" from Lorenzo Stoakes is a preparatoty refactoring and cleanup of the mremap() code. - The series "mm: MM owner tracking for large folios (!hugetlb) + CONFIG_NO_PAGE_MAPCOUNT" from David Hildenbrand reworks the manner in which we determine whether a large folio is known to be mapped exclusively into a single MM. - The series "mm/damon: add sysfs dirs for managing DAMOS filters based on handling layers" from SeongJae Park adds a couple of new sysfs directories to ease the management of DAMON/DAMOS filters. - The series "arch, mm: reduce code duplication in mem_init()" from Mike Rapoport consolidates many per-arch implementations of mem_init() into code generic code, where that is practical. - The series "mm/damon/sysfs: commit parameters online via damon_call()" from SeongJae Park continues the cleaning up of sysfs access to DAMON internal data. - The series "mm: page_ext: Introduce new iteration API" from Luiz Capitulino reworks the page_ext initialization to fix a boot-time crash which was observed with an unusual combination of compile and cmdline options. - The series "Buddy allocator like (or non-uniform) folio split" from Zi Yan reworks the code to split a folio into smaller folios. The main benefit is lessened memory consumption: fewer post-split folios are generated. - The series "Minimize xa_node allocation during xarry split" from Zi Yan reduces the number of xarray xa_nodes which are generated during an xarray split. - The series "drivers/base/memory: Two cleanups" from Gavin Shan performs some maintenance work on the drivers/base/memory code. - The series "Add tracepoints for lowmem reserves, watermarks and totalreserve_pages" from Martin Liu adds some more tracepoints to the page allocator code. - The series "mm/madvise: cleanup requests validations and classifications" from SeongJae Park cleans up some warts which SeongJae observed during his earlier madvise work. - The series "mm/hwpoison: Fix regressions in memory failure handling" from Shuai Xue addresses two quite serious regressions which Shuai has observed in the memory-failure implementation. - The series "mm: reliable huge page allocator" from Johannes Weiner makes huge page allocations cheaper and more reliable by reducing fragmentation. - The series "Minor memcg cleanups & prep for memdescs" from Matthew Wilcox is preparatory work for the future implementation of memdescs. - The series "track memory used by balloon drivers" from Nico Pache introduces a way to track memory used by our various balloon drivers. - The series "mm/damon: introduce DAMOS filter type for active pages" from Nhat Pham permits users to filter for active/inactive pages, separately for file and anon pages. - The series "Adding Proactive Memory Reclaim Statistics" from Hao Jia separates the proactive reclaim statistics from the direct reclaim statistics. - The series "mm/vmscan: don't try to reclaim hwpoison folio" from Jinjiang Tu fixes our handling of hwpoisoned pages within the reclaim code. * tag 'mm-stable-2025-03-30-16-52' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (431 commits) mm/page_alloc: remove unnecessary __maybe_unused in order_to_pindex() x86/mm: restore early initialization of high_memory for 32-bits mm/vmscan: don't try to reclaim hwpoison folio mm/hwpoison: introduce folio_contain_hwpoisoned_page() helper cgroup: docs: add pswpin and pswpout items in cgroup v2 doc mm: vmscan: split proactive reclaim statistics from direct reclaim statistics selftests/mm: speed up split_huge_page_test selftests/mm: uffd-unit-tests support for hugepages > 2M docs/mm/damon/design: document active DAMOS filter type mm/damon: implement a new DAMOS filter type for active pages fs/dax: don't disassociate zero page entries MM documentation: add "Unaccepted" meminfo entry selftests/mm: add commentary about 9pfs bugs fork: use __vmalloc_node() for stack allocation docs/mm: Physical Memory: Populate the "Zones" section xen: balloon: update the NR_BALLOON_PAGES state hv_balloon: update the NR_BALLOON_PAGES state balloon_compaction: update the NR_BALLOON_PAGES state meminfo: add a per node counter for balloon drivers mm: remove references to folio in __memcg_kmem_uncharge_page() ...
2025-03-31Merge tag 'trace-ringbuffer-v6.15-2' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace Pull ring-buffer updates from Steven Rostedt: - Restructure the persistent memory to have a "scratch" area Instead of hard coding the KASLR offset in the persistent memory by the ring buffer, push that work up to the callers of the persistent memory as they are the ones that need this information. The offsets and such is not important to the ring buffer logic and it should not be part of that. A scratch pad is now created when the caller allocates a ring buffer from persistent memory by stating how much memory it needs to save. - Allow where modules are loaded to be saved in the new scratch pad Save the addresses of modules when they are loaded into the persistent memory scratch pad. - A new module_for_each_mod() helper function was created With the acknowledgement of the module maintainers a new module helper function was created to iterate over all the currently loaded modules. This has a callback to be called for each module. This is needed for when tracing is started in the persistent buffer and the currently loaded modules need to be saved in the scratch area. - Expose the last boot information where the kernel and modules were loaded The last_boot_info file is updated to print out the addresses of where the kernel "_text" location was loaded from a previous boot, as well as where the modules are loaded. If the buffer is recording the current boot, it only prints "# Current" so that it does not expose the KASLR offset of the currently running kernel. - Allow the persistent ring buffer to be released (freed) To have this in production environments, where the kernel command line can not be changed easily, the ring buffer needs to be freed when it is not going to be used. The memory for the buffer will always be allocated at boot up, but if the system isn't going to enable tracing, the memory needs to be freed. Allow it to be freed and added back to the kernel memory pool. - Allow stack traces to print the function names in the persistent buffer Now that the modules are saved in the persistent ring buffer, if the same modules are loaded, the printing of the function names will examine the saved modules. If the module is found in the scratch area and is also loaded, then it will do the offset shift and use kallsyms to display the function name. If the address is not found, it simply displays the address from the previous boot in hex. * tag 'trace-ringbuffer-v6.15-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: tracing: Use _text and the kernel offset in last_boot_info tracing: Show last module text symbols in the stacktrace ring-buffer: Remove the unused variable bmeta tracing: Skip update_last_data() if cleared and remove active check for save_mod() tracing: Initialize scratch_size to zero to prevent UB tracing: Fix a compilation error without CONFIG_MODULES tracing: Freeable reserved ring buffer mm/memblock: Add reserved memory release function tracing: Update modules to persistent instances when loaded tracing: Show module names and addresses of last boot tracing: Have persistent trace instances save module addresses module: Add module_for_each_mod() function tracing: Have persistent trace instances save KASLR offset ring-buffer: Add ring_buffer_meta_scratch() ring-buffer: Add buffer meta data for persistent ring buffer ring-buffer: Use kaslr address instead of text delta ring-buffer: Fix bytes_dropped calculation issue