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2025-05-11mm: hugetlb: fix incorrect fallback for subpoolWupeng Ma
During our testing with hugetlb subpool enabled, we observe that hstate->resv_huge_pages may underflow into negative values. Root cause analysis reveals a race condition in subpool reservation fallback handling as follow: hugetlb_reserve_pages() /* Attempt subpool reservation */ gbl_reserve = hugepage_subpool_get_pages(spool, chg); /* Global reservation may fail after subpool allocation */ if (hugetlb_acct_memory(h, gbl_reserve) < 0) goto out_put_pages; out_put_pages: /* This incorrectly restores reservation to subpool */ hugepage_subpool_put_pages(spool, chg); When hugetlb_acct_memory() fails after subpool allocation, the current implementation over-commits subpool reservations by returning the full 'chg' value instead of the actual allocated 'gbl_reserve' amount. This discrepancy propagates to global reservations during subsequent releases, eventually causing resv_huge_pages underflow. This problem can be trigger easily with the following steps: 1. reverse hugepage for hugeltb allocation 2. mount hugetlbfs with min_size to enable hugetlb subpool 3. alloc hugepages with two task(make sure the second will fail due to insufficient amount of hugepages) 4. with for a few seconds and repeat step 3 which will make hstate->resv_huge_pages to go below zero. To fix this problem, return corrent amount of pages to subpool during the fallback after hugepage_subpool_get_pages is called. Link: https://lkml.kernel.org/r/20250410062633.3102457-1-mawupeng1@huawei.com Fixes: 1c5ecae3a93f ("hugetlbfs: add minimum size accounting to subpools") Signed-off-by: Wupeng Ma <mawupeng1@huawei.com> Tested-by: Joshua Hahn <joshua.hahnjy@gmail.com> Reviewed-by: Oscar Salvador <osalvador@suse.de> Cc: David Hildenbrand <david@redhat.com> Cc: Ma Wupeng <mawupeng1@huawei.com> Cc: Muchun Song <muchun.song@linux.dev> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-05-11Merge tag 'its-for-linus-20250509' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 ITS mitigation from Dave Hansen: "Mitigate Indirect Target Selection (ITS) issue. I'd describe this one as a good old CPU bug where the behavior is _obviously_ wrong, but since it just results in bad predictions it wasn't wrong enough to notice. Well, the researchers noticed and also realized that thus bug undermined a bunch of existing indirect branch mitigations. Thus the unusually wide impact on this one. Details: ITS is a bug in some Intel CPUs that affects indirect branches including RETs in the first half of a cacheline. Due to ITS such branches may get wrongly predicted to a target of (direct or indirect) branch that is located in the second half of a cacheline. Researchers at VUSec found this behavior and reported to Intel. Affected processors: - Cascade Lake, Cooper Lake, Whiskey Lake V, Coffee Lake R, Comet Lake, Ice Lake, Tiger Lake and Rocket Lake. Scope of impact: - Guest/host isolation: When eIBRS is used for guest/host isolation, the indirect branches in the VMM may still be predicted with targets corresponding to direct branches in the guest. - Intra-mode using cBPF: cBPF can be used to poison the branch history to exploit ITS. Realigning the indirect branches and RETs mitigates this attack vector. - User/kernel: With eIBRS enabled user/kernel isolation is *not* impacted by ITS. - Indirect Branch Prediction Barrier (IBPB): Due to this bug indirect branches may be predicted with targets corresponding to direct branches which were executed prior to IBPB. This will be fixed in the microcode. Mitigation: As indirect branches in the first half of cacheline are affected, the mitigation is to replace those indirect branches with a call to thunk that is aligned to the second half of the cacheline. RETs that take prediction from RSB are not affected, but they may be affected by RSB-underflow condition. So, RETs in the first half of cacheline are also patched to a return thunk that executes the RET aligned to second half of cacheline" * tag 'its-for-linus-20250509' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: selftest/x86/bugs: Add selftests for ITS x86/its: FineIBT-paranoid vs ITS x86/its: Use dynamic thunks for indirect branches x86/ibt: Keep IBT disabled during alternative patching mm/execmem: Unify early execmem_cache behaviour x86/its: Align RETs in BHB clear sequence to avoid thunking x86/its: Add support for RSB stuffing mitigation x86/its: Add "vmexit" option to skip mitigation on some CPUs x86/its: Enable Indirect Target Selection mitigation x86/its: Add support for ITS-safe return thunk x86/its: Add support for ITS-safe indirect thunk x86/its: Enumerate Indirect Target Selection (ITS) bug Documentation: x86/bugs/its: Add ITS documentation
2025-05-11Merge tag 'fixes-2025-05-11' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/rppt/memblock Pull memblock fixes from Mike Rapoport: - Mark set_high_memory() as __init to fix section mismatch - Accept memory allocated in memblock_double_array() to mitigate crash of SNP guests * tag 'fixes-2025-05-11' of git://git.kernel.org/pub/scm/linux/kernel/git/rppt/memblock: memblock: Accept allocated memory before use in memblock_double_array() mm,mm_init: Mark set_high_memory as __init
2025-05-09mm/execmem: Unify early execmem_cache behaviourPeter Zijlstra
Early kernel memory is RWX, only at the end of early boot (before SMP) do we mark things ROX. Have execmem_cache mirror this behaviour for early users. This avoids having to remember what code is execmem and what is not -- we can poke everything with impunity ;-) Also performance for not having to do endless text_poke_mm switches. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Pawan Gupta <pawan.kumar.gupta@linux.intel.com> Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Reviewed-by: Alexandre Chartre <alexandre.chartre@oracle.com>
2025-05-09mm/vmalloc: Enter lazy mmu mode while manipulating vmalloc ptesRyan Roberts
Wrap vmalloc's pte table manipulation loops with arch_enter_lazy_mmu_mode() / arch_leave_lazy_mmu_mode(). This provides the arch code with the opportunity to optimize the pte manipulations. Note that vmap_pfn() already uses lazy mmu mode since it delegates to apply_to_page_range() which enters lazy mmu mode for both user and kernel mappings. These hooks will shortly be used by arm64 to improve vmalloc performance. Reviewed-by: Uladzislau Rezki (Sony) <urezki@gmail.com> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com> Signed-off-by: Ryan Roberts <ryan.roberts@arm.com> Tested-by: Luiz Capitulino <luizcap@redhat.com> Link: https://lore.kernel.org/r/20250422081822.1836315-11-ryan.roberts@arm.com Signed-off-by: Will Deacon <will@kernel.org>
2025-05-09mm/vmalloc: Gracefully unmap huge ptesRyan Roberts
Commit f7ee1f13d606 ("mm/vmalloc: enable mapping of huge pages at pte level in vmap") added its support by reusing the set_huge_pte_at() API, which is otherwise only used for user mappings. But when unmapping those huge ptes, it continued to call ptep_get_and_clear(), which is a layering violation. To date, the only arch to implement this support is powerpc and it all happens to work ok for it. But arm64's implementation of ptep_get_and_clear() can not be safely used to clear a previous set_huge_pte_at(). So let's introduce a new arch opt-in function, arch_vmap_pte_range_unmap_size(), which can provide the size of a (present) pte. Then we can call huge_ptep_get_and_clear() to tear it down properly. Note that if vunmap_range() is called with a range that starts in the middle of a huge pte-mapped page, we must unmap the entire huge page so the behaviour is consistent with pmd and pud block mappings. In this case emit a warning just like we do for pmd/pud mappings. Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com> Reviewed-by: Uladzislau Rezki (Sony) <urezki@gmail.com> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Ryan Roberts <ryan.roberts@arm.com> Tested-by: Luiz Capitulino <luizcap@redhat.com> Link: https://lore.kernel.org/r/20250422081822.1836315-9-ryan.roberts@arm.com Signed-off-by: Will Deacon <will@kernel.org>
2025-05-09mm/vmalloc: Warn on improper use of vunmap_range()Ryan Roberts
A call to vmalloc_huge() may cause memory blocks to be mapped at pmd or pud level. But it is possible to subsequently call vunmap_range() on a sub-range of the mapped memory, which partially overlaps a pmd or pud. In this case, vmalloc unmaps the entire pmd or pud so that the no-overlapping portion is also unmapped. Clearly that would have a bad outcome, but it's not something that any callers do today as far as I can tell. So I guess it's just expected that callers will not do this. However, it would be useful to know if this happened in future; let's add a warning to cover the eventuality. Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Reviewed-by: Uladzislau Rezki (Sony) <urezki@gmail.com> Signed-off-by: Ryan Roberts <ryan.roberts@arm.com> Tested-by: Luiz Capitulino <luizcap@redhat.com> Link: https://lore.kernel.org/r/20250422081822.1836315-8-ryan.roberts@arm.com Signed-off-by: Will Deacon <will@kernel.org>
2025-05-09mm/page_table_check: Batch-check pmds/puds just like ptesRyan Roberts
Convert page_table_check_p[mu]d_set(...) to page_table_check_p[mu]ds_set(..., nr) to allow checking a contiguous set of pmds/puds in single batch. We retain page_table_check_p[mu]d_set(...) as macros that call new batch functions with nr=1 for compatibility. arm64 is about to reorganise its pte/pmd/pud helpers to reuse more code and to allow the implementation for huge_pte to more efficiently set ptes/pmds/puds in batches. We need these batch-helpers to make the refactoring possible. Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com> Reviewed-by: Pasha Tatashin <pasha.tatashin@soleen.com> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Ryan Roberts <ryan.roberts@arm.com> Tested-by: Luiz Capitulino <luizcap@redhat.com> Link: https://lore.kernel.org/r/20250422081822.1836315-4-ryan.roberts@arm.com Signed-off-by: Will Deacon <will@kernel.org>
2025-05-09memblock: Accept allocated memory before use in memblock_double_array()Tom Lendacky
When increasing the array size in memblock_double_array() and the slab is not yet available, a call to memblock_find_in_range() is used to reserve/allocate memory. However, the range returned may not have been accepted, which can result in a crash when booting an SNP guest: RIP: 0010:memcpy_orig+0x68/0x130 Code: ... RSP: 0000:ffffffff9cc03ce8 EFLAGS: 00010006 RAX: ff11001ff83e5000 RBX: 0000000000000000 RCX: fffffffffffff000 RDX: 0000000000000bc0 RSI: ffffffff9dba8860 RDI: ff11001ff83e5c00 RBP: 0000000000002000 R08: 0000000000000000 R09: 0000000000002000 R10: 000000207fffe000 R11: 0000040000000000 R12: ffffffff9d06ef78 R13: ff11001ff83e5000 R14: ffffffff9dba7c60 R15: 0000000000000c00 memblock_double_array+0xff/0x310 memblock_add_range+0x1fb/0x2f0 memblock_reserve+0x4f/0xa0 memblock_alloc_range_nid+0xac/0x130 memblock_alloc_internal+0x53/0xc0 memblock_alloc_try_nid+0x3d/0xa0 swiotlb_init_remap+0x149/0x2f0 mem_init+0xb/0xb0 mm_core_init+0x8f/0x350 start_kernel+0x17e/0x5d0 x86_64_start_reservations+0x14/0x30 x86_64_start_kernel+0x92/0xa0 secondary_startup_64_no_verify+0x194/0x19b Mitigate this by calling accept_memory() on the memory range returned before the slab is available. Prior to v6.12, the accept_memory() interface used a 'start' and 'end' parameter instead of 'start' and 'size', therefore the accept_memory() call must be adjusted to specify 'start + size' for 'end' when applying to kernels prior to v6.12. Cc: stable@vger.kernel.org # see patch description, needs adjustments for <= 6.11 Fixes: dcdfdd40fa82 ("mm: Add support for unaccepted memory") Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com> Link: https://lore.kernel.org/r/da1ac73bf4ded761e21b4e4bb5178382a580cd73.1746725050.git.thomas.lendacky@amd.com Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
2025-05-08kbuild: Switch from -Wvla to -Wvla-larger-than=1Kees Cook
Variable Length Arrays (VLAs) on the stack must not be used in the kernel. Function parameter VLAs[1] should be usable, but -Wvla will warn for those. For example, this will produce a warning but it is not using a stack VLA: int something(size_t n, int array[n]) { ... Clang has no way yet to distinguish between the VLA types[2], so depend on GCC for now to keep stack VLAs out of the tree by using GCC's -Wvla-larger-than=N option (though GCC may split -Wvla similarly[3] to how Clang is planning to). While GCC 8+ supports -Wvla-larger-than, only 9+ supports ...=0[4], so use -Wvla-larger-than=1. Adjust mm/kasan/Makefile to remove it from CFLAGS (GCC <9 appears unable to disable the warning correctly[5]). The VLA usage in lib/test_ubsan.c was removed in commit 9d7ca61b1366 ("lib/test_ubsan.c: VLA no longer used in kernel") so the lib/Makefile disabling of VLA checking can be entirely removed. Link: https://en.cppreference.com/w/c/language/array [1] Link: https://github.com/llvm/llvm-project/issues/57098 [2] Link: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98217 [3] Link: https://lore.kernel.org/lkml/7780883c-0ac8-4aaa-b850-469e33b50672@linux.ibm.com/ [4] Link: https://lore.kernel.org/r/202505071331.4iOzqmuE-lkp@intel.com/ [5] Reviewed-by: Nathan Chancellor <nathan@kernel.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Tested-by: Venkat Rao Bagalkote <venkat88@linux.ibm.com> Link: https://lore.kernel.org/r/20250418213235.work.532-kees@kernel.org Signed-off-by: Kees Cook <kees@kernel.org>
2025-05-08Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski
Cross-merge networking fixes after downstream PR (net-6.15-rc6). No conflicts. Adjacent changes: net/core/dev.c: 08e9f2d584c4 ("net: Lock netdevices during dev_shutdown") a82dc19db136 ("net: avoid potential race between netdev_get_by_index_lock() and netns switch") Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-05-07mm: fix folio_pte_batch() on XEN PVPetr Vaněk
On XEN PV, folio_pte_batch() can incorrectly batch beyond the end of a folio due to a corner case in pte_advance_pfn(). Specifically, when the PFN following the folio maps to an invalidated MFN, expected_pte = pte_advance_pfn(expected_pte, nr); produces a pte_none(). If the actual next PTE in memory is also pte_none(), the pte_same() succeeds, if (!pte_same(pte, expected_pte)) break; the loop is not broken, and batching continues into unrelated memory. For example, with a 4-page folio, the PTE layout might look like this: [ 53.465673] [ T2552] folio_pte_batch: printing PTE values at addr=0x7f1ac9dc5000 [ 53.465674] [ T2552] PTE[453] = 000000010085c125 [ 53.465679] [ T2552] PTE[454] = 000000010085d125 [ 53.465682] [ T2552] PTE[455] = 000000010085e125 [ 53.465684] [ T2552] PTE[456] = 000000010085f125 [ 53.465686] [ T2552] PTE[457] = 0000000000000000 <-- not present [ 53.465689] [ T2552] PTE[458] = 0000000101da7125 pte_advance_pfn(PTE[456]) returns a pte_none() due to invalid PFN->MFN mapping. The next actual PTE (PTE[457]) is also pte_none(), so the loop continues and includes PTE[457] in the batch, resulting in 5 batched entries for a 4-page folio. This triggers the following warning: [ 53.465751] [ T2552] page: refcount:85 mapcount:20 mapping:ffff88813ff4f6a8 index:0x110 pfn:0x10085c [ 53.465754] [ T2552] head: order:2 mapcount:80 entire_mapcount:0 nr_pages_mapped:4 pincount:0 [ 53.465756] [ T2552] memcg:ffff888003573000 [ 53.465758] [ T2552] aops:0xffffffff8226fd20 ino:82467c dentry name(?):"libc.so.6" [ 53.465761] [ T2552] flags: 0x2000000000416c(referenced|uptodate|lru|active|private|head|node=0|zone=2) [ 53.465764] [ T2552] raw: 002000000000416c ffffea0004021f08 ffffea0004021908 ffff88813ff4f6a8 [ 53.465767] [ T2552] raw: 0000000000000110 ffff888133d8bd40 0000005500000013 ffff888003573000 [ 53.465768] [ T2552] head: 002000000000416c ffffea0004021f08 ffffea0004021908 ffff88813ff4f6a8 [ 53.465770] [ T2552] head: 0000000000000110 ffff888133d8bd40 0000005500000013 ffff888003573000 [ 53.465772] [ T2552] head: 0020000000000202 ffffea0004021701 000000040000004f 00000000ffffffff [ 53.465774] [ T2552] head: 0000000300000003 8000000300000002 0000000000000013 0000000000000004 [ 53.465775] [ T2552] page dumped because: VM_WARN_ON_FOLIO((_Generic((page + nr_pages - 1), const struct page *: (const struct folio *)_compound_head(page + nr_pages - 1), struct page *: (struct folio *)_compound_head(page + nr_pages - 1))) != folio) Original code works as expected everywhere, except on XEN PV, where pte_advance_pfn() can yield a pte_none() after balloon inflation due to MFNs invalidation. In XEN, pte_advance_pfn() ends up calling __pte()->xen_make_pte()->pte_pfn_to_mfn(), which returns pte_none() when mfn == INVALID_P2M_ENTRY. The pte_pfn_to_mfn() documents that nastiness: If there's no mfn for the pfn, then just create an empty non-present pte. Unfortunately this loses information about the original pfn, so pte_mfn_to_pfn is asymmetric. While such hacks should certainly be removed, we can do better in folio_pte_batch() and simply check ahead of time how many PTEs we can possibly batch in our folio. This way, we can not only fix the issue but cleanup the code: removing the pte_pfn() check inside the loop body and avoiding end_ptr comparison + arithmetic. Link: https://lkml.kernel.org/r/20250502215019.822-2-arkamar@atlas.cz Fixes: f8d937761d65 ("mm/memory: optimize fork() with PTE-mapped THP") Co-developed-by: David Hildenbrand <david@redhat.com> Signed-off-by: David Hildenbrand <david@redhat.com> Signed-off-by: Petr Vaněk <arkamar@atlas.cz> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-05-07mm/hugetlb: copy the CMA flag when demotingFrank van der Linden
Since commit d2d786714080 ("mm/hugetlb: enable bootmem allocation from CMA areas"), a flag is used to mark hugetlb folios as allocated from CMA. This flag is also used to decide if it should be freed to CMA. However, the flag isn't copied to the smaller folios when a hugetlb folio is broken up for demotion, which would cause it to be freed incorrectly. Fix this by copying the flag to the smaller order hugetlb pages created from the original one. Link: https://lkml.kernel.org/r/20250501044325.20365-1-fvdl@google.com Fixes: d2d786714080 ("mm/hugetlb: enable bootmem allocation from CMA areas") Signed-off-by: Frank van der Linden <fvdl@google.com> Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com> Reviewed-by: Oscar Salvador <osalvador@suse.de> Reviewed-by: Jane Chu <Jane.Chu@oracle.com> Cc: Muchun Song <muchun.song@linux.dev> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-05-07mm, swap: fix false warning for large allocation with !THP_SWAPKairui Song
The !CONFIG_THP_SWAP check existed before just fine because slot cache would reject high order allocation and let the caller split all folios and try again. But slot cache is gone, so large allocation will directly go to the allocator, and the allocator should just fail silently to inform caller to do the folio split, this is totally fine and expected. Remove this meaningless warning. Link: https://lkml.kernel.org/r/20250429094803.85518-1-ryncsn@gmail.com Fixes: 0ff67f990bd4 ("mm, swap: remove swap slot cache") Signed-off-by: Kairui Song <kasong@tencent.com> Reported-by: Heiko Carstens <hca@linux.ibm.com> Closes: https://lore.kernel.org/linux-mm/20250428135252.25453B17-hca@linux.ibm.com/ Tested-by: Heiko Carstens <hca@linux.ibm.com> Cc: Baoquan He <bhe@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-05-07mm: vmalloc: support more granular vrealloc() sizingKees Cook
Introduce struct vm_struct::requested_size so that the requested (re)allocation size is retained separately from the allocated area size. This means that KASAN will correctly poison the correct spans of requested bytes. This also means we can support growing the usable portion of an allocation that can already be supported by the existing area's existing allocation. Link: https://lkml.kernel.org/r/20250426001105.it.679-kees@kernel.org Fixes: 3ddc2fefe6f3 ("mm: vmalloc: implement vrealloc()") Signed-off-by: Kees Cook <kees@kernel.org> Reported-by: Erhard Furtner <erhard_f@mailbox.org> Closes: https://lore.kernel.org/all/20250408192503.6149a816@outsider.home/ Reviewed-by: Danilo Krummrich <dakr@kernel.org> Cc: Michal Hocko <mhocko@suse.com> Cc: "Uladzislau Rezki (Sony)" <urezki@gmail.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-05-07mm/huge_memory: fix dereferencing invalid pmd migration entryGavin Guo
When migrating a THP, concurrent access to the PMD migration entry during a deferred split scan can lead to an invalid address access, as illustrated below. To prevent this invalid access, it is necessary to check the PMD migration entry and return early. In this context, there is no need to use pmd_to_swp_entry and pfn_swap_entry_to_page to verify the equality of the target folio. Since the PMD migration entry is locked, it cannot be served as the target. Mailing list discussion and explanation from Hugh Dickins: "An anon_vma lookup points to a location which may contain the folio of interest, but might instead contain another folio: and weeding out those other folios is precisely what the "folio != pmd_folio((*pmd)" check (and the "risk of replacing the wrong folio" comment a few lines above it) is for." BUG: unable to handle page fault for address: ffffea60001db008 CPU: 0 UID: 0 PID: 2199114 Comm: tee Not tainted 6.14.0+ #4 NONE Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 RIP: 0010:split_huge_pmd_locked+0x3b5/0x2b60 Call Trace: <TASK> try_to_migrate_one+0x28c/0x3730 rmap_walk_anon+0x4f6/0x770 unmap_folio+0x196/0x1f0 split_huge_page_to_list_to_order+0x9f6/0x1560 deferred_split_scan+0xac5/0x12a0 shrinker_debugfs_scan_write+0x376/0x470 full_proxy_write+0x15c/0x220 vfs_write+0x2fc/0xcb0 ksys_write+0x146/0x250 do_syscall_64+0x6a/0x120 entry_SYSCALL_64_after_hwframe+0x76/0x7e The bug is found by syzkaller on an internal kernel, then confirmed on upstream. Link: https://lkml.kernel.org/r/20250421113536.3682201-1-gavinguo@igalia.com Link: https://lore.kernel.org/all/20250414072737.1698513-1-gavinguo@igalia.com/ Link: https://lore.kernel.org/all/20250418085802.2973519-1-gavinguo@igalia.com/ Fixes: 84c3fc4e9c56 ("mm: thp: check pmd migration entry in common path") Signed-off-by: Gavin Guo <gavinguo@igalia.com> Acked-by: David Hildenbrand <david@redhat.com> Acked-by: Hugh Dickins <hughd@google.com> Acked-by: Zi Yan <ziy@nvidia.com> Reviewed-by: Gavin Shan <gshan@redhat.com> Cc: Florent Revest <revest@google.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Miaohe Lin <linmiaohe@huawei.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-05-06mm,mm_init: Mark set_high_memory as __initOscar Salvador
set_high_memory() touches arch_zone_lowest_possible_pfn which is marked as __initdata, which creates a section mismatch. Since the only user of the function is free_area_init() which is also marked as __init, mark set_high_memory() as __init as well. Signed-off-by: Oscar Salvador <osalvador@suse.de> Reported-by: kernel test robot <lkp@intel.com> Closes: https://lore.kernel.org/oe-kbuild-all/202505060901.Qcs06UoB-lkp@intel.com/ Link: https://lore.kernel.org/r/20250506111012.108743-1-osalvador@suse.de Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
2025-05-06swapfile: disable swapon for bs > ps devicesLuis Chamberlain
Devices which have a requirement for bs > ps cannot be supported for swap as swap still needs work. Now that the block device cache sets the min order for block devices we need this stop gap otherwise all swap operations are rejected. Without this you'll end up with errors on these devices as the swap code still needs much love to support min order. With this we at least now put a stop gap of its use, until the swap subsystem completes its major overhaul: mkswap: /dev/nvme3n1: warning: wiping old swap signature. Setting up swapspace version 1, size = 100 GiB (107374178304 bytes) no label, UUID=6af76b5c-7e7b-4902-b7f7-4c24dde6fa36 swapon: /dev/nvme3n1: swapon failed: Invalid argument Reviewed-by: Davidlohr Bueso <dave@stgolabs.net> Signed-off-by: Luis Chamberlain <mcgrof@kernel.org> Link: https://lore.kernel.org/aBkS926thy9zvdZb@bombadil.infradead.org Signed-off-by: Christian Brauner <brauner@kernel.org>
2025-05-05mm: remove NR_BOUNCE zone statChristoph Hellwig
The stat is always 0 now, so remove it and hardwire the user visible output to 0. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Hannes Reinecke <hare@suse.de> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Link: https://lore.kernel.org/r/20250505081138.3435992-8-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2025-05-03mm: Add vmalloc_huge_node()Peter Zijlstra
To enable node specific hash-tables using huge pages if possible. [bigeasy: use __vmalloc_node_range_noprof(), add nommu bits, inline vmalloc_huge] Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20250416162921.513656-3-bigeasy@linutronix.de
2025-05-02Merge 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
2025-05-01Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski
Cross-merge networking fixes after downstream PR (net-6.15-rc5). No conflicts or adjacent changes. Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-04-30Kbuild: remove structleak gcc pluginArnd Bergmann
gcc-12 and higher support the -ftrivial-auto-var-init= flag, after gcc-8 is the minimum version, this is half of the supported ones, and the vast majority of the versions that users are actually likely to have, so it seems like a good time to stop having the fallback plugin implementation Older toolchains are still able to build kernels normally without this plugin, but won't be able to use variable initialization.. Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2025-04-29Merge 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()
2025-04-24Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski
Cross-merge networking fixes after downstream PR (net-6.15-rc4). This pull includes wireless and a fix to vxlan which isn't in Linus's tree just yet. The latter creates with a silent conflict / build breakage, so merging it now to avoid causing problems. drivers/net/vxlan/vxlan_vnifilter.c 094adad91310 ("vxlan: Use a single lock to protect the FDB table") 087a9eb9e597 ("vxlan: vnifilter: Fix unlocked deletion of default FDB entry") https://lore.kernel.org/20250423145131.513029-1-idosch@nvidia.com No "normal" conflicts, or adjacent changes. Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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>
2025-04-21fs: add S_ANON_INODEChristian Brauner
This makes it easy to detect proper anonymous inodes and to ensure that we can detect them in codepaths such as readahead(). Readahead on anonymous inodes didn't work because they didn't have a proper mode. Now that they have we need to retain EINVAL being returned otherwise LTP will fail. We also need to ensure that ioctls aren't simply fired like they are for regular files so things like inotify inodes continue to correctly call their own ioctl handlers as in [1]. Reported-by: Xilin Wu <sophon@radxa.com> Link: https://lore.kernel.org/3A9139D5CD543962+89831381-31b9-4392-87ec-a84a5b3507d8@radxa.com [1] Link: https://lore.kernel.org/7a1a7076-ff6b-4cb0-94e7-7218a0a44028@sirena.org.uk 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 git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski
Cross-merge networking fixes after downstream PR (net-6.15-rc3). No conflicts. Adjacent changes: tools/net/ynl/pyynl/ynl_gen_c.py 4d07bbf2d456 ("tools: ynl-gen: don't declare loop iterator in place") 7e8ba0c7de2b ("tools: ynl: don't use genlmsghdr in classic netlink") Signed-off-by: Jakub Kicinski <kuba@kernel.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>
2025-04-14page_pool: Move pp_magic check into helper functionsToke Høiland-Jørgensen
Since we are about to stash some more information into the pp_magic field, let's move the magic signature checks into a pair of helper functions so it can be changed in one place. Reviewed-by: Mina Almasry <almasrymina@google.com> Tested-by: Yonglong Liu <liuyonglong@huawei.com> Acked-by: Jesper Dangaard Brouer <hawk@kernel.org> Reviewed-by: Ilias Apalodimas <ilias.apalodimas@linaro.org> Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com> Link: https://patch.msgid.link/20250409-page-pool-track-dma-v9-1-6a9ef2e0cba8@redhat.com Signed-off-by: Jakub Kicinski <kuba@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>
generated by cgit (git 2.34.1) at 2025-07-15 11:07:15 +0000