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2025-10-29mm: remove __filemap_fdatawriteChristoph Hellwig
And rewrite filemap_fdatawrite to use filemap_fdatawrite_range instead to have a simpler call chain. Signed-off-by: Christoph Hellwig <hch@lst.de> Link: https://patch.msgid.link/20251024080431.324236-8-hch@lst.de Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Christian Brauner <brauner@kernel.org>
2025-10-29mm,btrfs: add a filemap_flush_nr helperChristoph Hellwig
Abstract out the btrfs-specific behavior of kicking off I/O on a number of pages on an address_space into a well-defined helper. Note: there is no kerneldoc comment for the new function because it is not part of the public API. Signed-off-by: Christoph Hellwig <hch@lst.de> Link: https://patch.msgid.link/20251024080431.324236-7-hch@lst.de Reviewed-by: David Hildenbrand <david@redhat.com> Reviewed-by: Damien Le Moal <dlemoal@kernel.org> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Christian Brauner <brauner@kernel.org>
2025-10-29mm: don't opencode filemap_fdatawrite_range in filemap_invalidate_inodeChristoph Hellwig
Use filemap_fdatawrite_range instead of opencoding the logic using filemap_fdatawrite_wbc. Signed-off-by: Christoph Hellwig <hch@lst.de> Link: https://patch.msgid.link/20251024080431.324236-2-hch@lst.de Reviewed-by: David Hildenbrand <david@redhat.com> Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: Damien Le Moal <dlemoal@kernel.org> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Signed-off-by: Christian Brauner <brauner@kernel.org>
2025-10-27slab: convert setup_slub_debug() to use __core_param_cb()Petr Tesarik
Use __core_param_cb() to parse the "slab_debug" kernel parameter instead of the obsolescent __setup(). For now, the parameter is not exposed in sysfs, and no get ops is provided. There is a slight change in behavior. Before this patch, the following parameter would silently turn on full debugging for all slabs: slub_debug_yada_yada_gotta_love_this=hail_satan! This syntax is now rejected, and the parameter will be passed to user space, making the kernel a holier place. Signed-off-by: Petr Tesarik <ptesarik@suse.com> Link: https://patch.msgid.link/9674b34861394088c7853edf8e9d2b439fd4b42f.1761324765.git.ptesarik@suse.com Reviewed-by: Harry Yoo <harry.yoo@oracle.com> Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
2025-10-27slab: constify slab debug stringsPetr Tesarik
Since the string passed to slab_debug is never modified, use pointers to const char in all places where it is processed. No functional changes intended. Signed-off-by: Petr Tesarik <ptesarik@suse.com> Reviewed-by: Christoph Lameter <cl@gentwo.org> Link: https://patch.msgid.link/819095b921f6ae03bb54fd69ee4020e2a3aef675.1761324765.git.ptesarik@suse.com Reviewed-by: Harry Yoo <harry.yoo@oracle.com> Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
2025-10-24Merge tag 'slab-for-6.18-rc3' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/vbabka/slab Pull slab fixes from Vlastimil Babka: - Two fixes for race conditions in obj_exts allocation (Hao Ge) - Fix for slab accounting imbalance due to deferred slab decativation (Vlastimil Babka) * tag 'slab-for-6.18-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/vbabka/slab: slab: Fix obj_ext mistakenly considered NULL due to race condition slab: fix slab accounting imbalance due to defer_deactivate_slab() slab: Avoid race on slab->obj_exts in alloc_slab_obj_exts
2025-10-24slab: Fix obj_ext mistakenly considered NULL due to race conditionHao Ge
If two competing threads enter alloc_slab_obj_exts(), and the one that allocates the vector wins the cmpxchg(), the other thread that failed allocation mistakenly assumes that slab->obj_exts is still empty due to its own allocation failure. This will then trigger warnings with CONFIG_MEM_ALLOC_PROFILING_DEBUG checks in the subsequent free path. Therefore, let's check the result of cmpxchg() to see if marking the allocation as failed was successful. If it wasn't, check whether the winning side has succeeded its allocation (it might have been also marking it as failed) and if yes, return success. Suggested-by: Harry Yoo <harry.yoo@oracle.com> Fixes: f7381b911640 ("slab: mark slab->obj_exts allocation failures unconditionally") Cc: <stable@vger.kernel.org> Signed-off-by: Hao Ge <gehao@kylinos.cn> Link: https://patch.msgid.link/20251023143313.1327968-1-hao.ge@linux.dev Reviewed-by: Suren Baghdasaryan <surenb@google.com> Reviewed-by: Harry Yoo <harry.yoo@oracle.com> Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
2025-10-23slab: fix slab accounting imbalance due to defer_deactivate_slab()Vlastimil Babka
Since commit af92793e52c3 ("slab: Introduce kmalloc_nolock() and kfree_nolock().") there's a possibility in alloc_single_from_new_slab() that we discard the newly allocated slab if we can't spin and we fail to trylock. As a result we don't perform inc_slabs_node() later in the function. Instead we perform a deferred deactivate_slab() which can either put the unacounted slab on partial list, or discard it immediately while performing dec_slabs_node(). Either way will cause an accounting imbalance. Fix this by not marking the slab as frozen, and using free_slab() instead of deactivate_slab() for non-frozen slabs in free_deferred_objects(). For CONFIG_SLUB_TINY, that's the only possible case. By not using discard_slab() we avoid dec_slabs_node(). Fixes: af92793e52c3 ("slab: Introduce kmalloc_nolock() and kfree_nolock().") Link: https://patch.msgid.link/20251023-fix-slab-accounting-v2-1-0e62d50986ea@suse.cz Reviewed-by: Harry Yoo <harry.yoo@oracle.com> Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
2025-10-22Merge tag 'mm-hotfixes-stable-2025-10-22-12-43' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Pull hotfixes from Andrew Morton: "17 hotfixes. 12 are cc:stable and 14 are for MM. There's a two-patch DAMON series from SeongJae Park which addresses a missed check and possible memory leak. Apart from that it's all singletons - please see the changelogs for details" * tag 'mm-hotfixes-stable-2025-10-22-12-43' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: csky: abiv2: adapt to new folio flags field mm/damon/core: use damos_commit_quota_goal() for new goal commit mm/damon/core: fix potential memory leak by cleaning ops_filter in damon_destroy_scheme hugetlbfs: move lock assertions after early returns in huge_pmd_unshare() vmw_balloon: indicate success when effectively deflating during migration mm/damon/core: fix list_add_tail() call on damon_call() mm/mremap: correctly account old mapping after MREMAP_DONTUNMAP remap mm: prevent poison consumption when splitting THP ocfs2: clear extent cache after moving/defragmenting extents mm: don't spin in add_stack_record when gfp flags don't allow dma-debug: don't report false positives with DMA_BOUNCE_UNALIGNED_KMALLOC mm/damon/sysfs: dealloc commit test ctx always mm/damon/sysfs: catch commit test ctx alloc failure hung_task: fix warnings caused by unaligned lock pointers
2025-10-22memfd,selinux: call security_inode_init_security_anon()Thiébaud Weksteen
Prior to this change, no security hooks were called at the creation of a memfd file. It means that, for SELinux as an example, it will receive the default type of the filesystem that backs the in-memory inode. In most cases, that would be tmpfs, but if MFD_HUGETLB is passed, it will be hugetlbfs. Both can be considered implementation details of memfd. It also means that it is not possible to differentiate between a file coming from memfd_create and a file coming from a standard tmpfs mount point. Additionally, no permission is validated at creation, which differs from the similar memfd_secret syscall. Call security_inode_init_security_anon during creation. This ensures that the file is setup similarly to other anonymous inodes. On SELinux, it means that the file will receive the security context of its task. The ability to limit fexecve on memfd has been of interest to avoid potential pitfalls where /proc/self/exe or similar would be executed [1][2]. Reuse the "execute_no_trans" and "entrypoint" access vectors, similarly to the file class. These access vectors may not make sense for the existing "anon_inode" class. Therefore, define and assign a new class "memfd_file" to support such access vectors. Guard these changes behind a new policy capability named "memfd_class". [1] https://crbug.com/1305267 [2] https://lore.kernel.org/lkml/20221215001205.51969-1-jeffxu@google.com/ Signed-off-by: Thiébaud Weksteen <tweek@google.com> Reviewed-by: Stephen Smalley <stephen.smalley.work@gmail.com> Tested-by: Stephen Smalley <stephen.smalley.work@gmail.com> Acked-by: Hugh Dickins <hughd@google.com> [PM: subj tweak] Signed-off-by: Paul Moore <paul@paul-moore.com>
2025-10-21mm/damon/core: use damos_commit_quota_goal() for new goal commitSeongJae Park
When damos_commit_quota_goals() is called for adding new DAMOS quota goals of DAMOS_QUOTA_USER_INPUT metric, current_value fields of the new goals should be also set as requested. However, damos_commit_quota_goals() is not updating the field for the case, since it is setting only metrics and target values using damos_new_quota_goal(), and metric-optional union fields using damos_commit_quota_goal_union(). As a result, users could see the first current_value parameter that committed online with a new quota goal is ignored. Users are assumed to commit the current_value for DAMOS_QUOTA_USER_INPUT quota goals, since it is being used as a feedback. Hence the real impact would be subtle. That said, this is obviously not intended behavior. Fix the issue by using damos_commit_quota_goal() which sets all quota goal parameters, instead of damos_commit_quota_goal_union(), which sets only the union fields. Link: https://lkml.kernel.org/r/20251014001846.279282-1-sj@kernel.org Fixes: 1aef9df0ee90 ("mm/damon/core: commit damos_quota_goal->nid") Signed-off-by: SeongJae Park <sj@kernel.org> Cc: <stable@vger.kernel.org> [6.16+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-10-21mm/damon/core: fix potential memory leak by cleaning ops_filter in ↵Enze Li
damon_destroy_scheme Currently, damon_destroy_scheme() only cleans up the filter list but leaves ops_filter untouched, which could lead to memory leaks when a scheme is destroyed. This patch ensures both filter and ops_filter are properly freed in damon_destroy_scheme(), preventing potential memory leaks. Link: https://lkml.kernel.org/r/20251014084225.313313-1-lienze@kylinos.cn Fixes: ab82e57981d0 ("mm/damon/core: introduce damos->ops_filters") Signed-off-by: Enze Li <lienze@kylinos.cn> Reviewed-by: SeongJae Park <sj@kernel.org> Tested-by: SeongJae Park <sj@kernel.org> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-10-21hugetlbfs: move lock assertions after early returns in huge_pmd_unshare()Deepanshu Kartikey
When hugetlb_vmdelete_list() processes VMAs during truncate operations, it may encounter VMAs where huge_pmd_unshare() is called without the required shareable lock. This triggers an assertion failure in hugetlb_vma_assert_locked(). The previous fix in commit dd83609b8898 ("hugetlbfs: skip VMAs without shareable locks in hugetlb_vmdelete_list") skipped entire VMAs without shareable locks to avoid the assertion. However, this prevented pages from being unmapped and freed, causing a regression in fallocate(PUNCH_HOLE) operations where pages were not freed immediately, as reported by Mark Brown. Instead of checking locks in the caller or skipping VMAs, move the lock assertions in huge_pmd_unshare() to after the early return checks. The assertions are only needed when actual PMD unsharing work will be performed. If the function returns early because sz != PMD_SIZE or the PMD is not shared, no locks are required and assertions should not fire. This approach reverts the VMA skipping logic from commit dd83609b8898 ("hugetlbfs: skip VMAs without shareable locks in hugetlb_vmdelete_list") while moving the assertions to avoid the assertion failure, keeping all the logic within huge_pmd_unshare() itself and allowing page unmapping and freeing to proceed for all VMAs. Link: https://lkml.kernel.org/r/20251014113344.21194-1-kartikey406@gmail.com Fixes: dd83609b8898 ("hugetlbfs: skip VMAs without shareable locks in hugetlb_vmdelete_list") Signed-off-by: Deepanshu Kartikey <kartikey406@gmail.com> Reported-by: <syzbot+f26d7c75c26ec19790e7@syzkaller.appspotmail.com> Reported-by: Mark Brown <broonie@kernel.org> Closes: https://syzkaller.appspot.com/bug?extid=f26d7c75c26ec19790e7 Suggested-by: David Hildenbrand <david@redhat.com> Suggested-by: Oscar Salvador <osalvador@suse.de> Tested-by: <syzbot+f26d7c75c26ec19790e7@syzkaller.appspotmail.com> Acked-by: David Hildenbrand <david@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-10-21mm/damon/core: fix list_add_tail() call on damon_call()SeongJae Park
Each damon_ctx maintains callback requests using a linked list (damon_ctx->call_controls). When a new callback request is received via damon_call(), the new request should be added to the list. However, the function is making a mistake at list_add_tail() invocation: putting the new item to add and the list head to add it before, in the opposite order. Because of the linked list manipulation implementation, the new request can still be reached from the context's list head. But the list items that were added before the new request are dropped from the list. As a result, the callbacks are unexpectedly not invocated. Worse yet, if the dropped callback requests were dynamically allocated, the memory is leaked. Actually DAMON sysfs interface is using a dynamically allocated repeat-mode callback request for automatic essential stats update. And because the online DAMON parameters commit is using a non-repeat-mode callback request, the issue can easily be reproduced, like below. # damo start --damos_action stat --refresh_stat 1s # damo tune --damos_action stat --refresh_stat 1s The first command dynamically allocates the repeat-mode callback request for automatic essential stat update. Users can see the essential stats are automatically updated for every second, using the sysfs interface. The second command calls damon_commit() with a new callback request that was made for the commit. As a result, the previously added repeat-mode callback request is dropped from the list. The automatic stats refresh stops working, and the memory for the repeat-mode callback request is leaked. It can be confirmed using kmemleak. Fix the mistake on the list_add_tail() call. Link: https://lkml.kernel.org/r/20251014205939.1206-1-sj@kernel.org Fixes: 004ded6bee11 ("mm/damon: accept parallel damon_call() requests") Signed-off-by: SeongJae Park <sj@kernel.org> Cc: <stable@vger.kernel.org> [6.17+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-10-21mm/mremap: correctly account old mapping after MREMAP_DONTUNMAP remapLorenzo Stoakes
Commit b714ccb02a76 ("mm/mremap: complete refactor of move_vma()") mistakenly introduced a new behaviour - clearing the VM_ACCOUNT flag of the old mapping when a mapping is mremap()'d with the MREMAP_DONTUNMAP flag set. While we always clear the VM_LOCKED and VM_LOCKONFAULT flags for the old mapping (the page tables have been moved, so there is no data that could possibly be locked in memory), there is no reason to touch any other VMA flags. This is because after the move the old mapping is in a state as if it were freshly mapped. This implies that the attributes of the mapping ought to remain the same, including whether or not the mapping is accounted. Link: https://lkml.kernel.org/r/20251013165836.273113-1-lorenzo.stoakes@oracle.com Signed-off-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Fixes: b714ccb02a76 ("mm/mremap: complete refactor of move_vma()") Reviewed-by: Pedro Falcato <pfalcato@suse.de> Cc: Jann Horn <jannh@google.com> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-10-21slab: Avoid race on slab->obj_exts in alloc_slab_obj_extsHao Ge
If two competing threads enter alloc_slab_obj_exts() and one of them fails to allocate the object extension vector, it might override the valid slab->obj_exts allocated by the other thread with OBJEXTS_ALLOC_FAIL. This will cause the thread that lost this race and expects a valid pointer to dereference a NULL pointer later on. Update slab->obj_exts atomically using cmpxchg() to avoid slab->obj_exts overrides by racing threads. Thanks for Vlastimil and Suren's help with debugging. Fixes: f7381b911640 ("slab: mark slab->obj_exts allocation failures unconditionally") Cc: <stable@vger.kernel.org> Suggested-by: Suren Baghdasaryan <surenb@google.com> Signed-off-by: Hao Ge <gehao@kylinos.cn> Reviewed-by: Harry Yoo <harry.yoo@oracle.com> Reviewed-by: Suren Baghdasaryan <surenb@google.com> Link: https://patch.msgid.link/20251021010353.1187193-1-hao.ge@linux.dev Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
2025-10-21Merge branch 'memory-hotplug'Heiko Carstens
Sumanth Korikkar says: ==================== Provide a new interface for dynamic configuration and deconfiguration of hotplug memory on s390, allowing with/without memmap_on_memory support. It is a follow up on the discussion with David when introducing memmap_on_memory support for s390 and support dynamic (de)configuration of memory: https://lore.kernel.org/all/ee492da8-74b4-4a97-8b24-73e07257f01d@redhat.com/ https://lore.kernel.org/all/20241202082732.3959803-1-sumanthk@linux.ibm.com/ The original motivation for introducing memmap_on_memory on s390 was to avoid using online memory to store struct pages metadata, particularly for standby memory blocks. This became critical in cases where there was an imbalance between standby and online memory, potentially leading to boot failures due to insufficient memory for metadata allocation. To address this, memmap_on_memory was utilized on s390. However, in its current form, it adds struct pages metadata at the start of each memory block at the time of addition (only standby memory), and this configuration is static. It cannot be changed at runtime (When the user needs continuous physical memory). Inorder to provide more flexibility to the user and overcome the above limitation, add an option to dynamically configure and deconfigure hotpluggable memory block with/without memmap_on_memory. With the new interface, s390 will not add all possible hotplug memory in advance, like before, to make it visible in sysfs for online/offline actions. Instead, before memory block can be set online, it has to be configured via a new interface in /sys/firmware/memory/memoryX/config, which makes s390 similar to others. i.e. Adding of hotpluggable memory is controlled by the user instead of adding it at boottime. s390 kernel sysfs interface to configure/deconfigure memory with memmap_on_memory (with upcoming lsmem changes): * Initial memory layout: lsmem -o RANGE,SIZE,STATE,BLOCK,CONFIGURED,MEMMAP_ON_MEMORY RANGE SIZE STATE BLOCK CONFIGURED MEMMAP_ON_MEMORY 0x00000000-0x7fffffff 2G online 0-15 yes no 0x80000000-0xffffffff 2G offline 16-31 no yes * Configure memory echo 1 > /sys/firmware/memory/memory16/config lsmem -o RANGE,SIZE,STATE,BLOCK,CONFIGURED,MEMMAP_ON_MEMORY RANGE SIZE STATE BLOCK CONFIGURED MEMMAP_ON_MEMORY 0x00000000-0x7fffffff 2G online 0-15 yes no 0x80000000-0x87ffffff 128M offline 16 yes yes 0x88000000-0xffffffff 1.9G offline 17-31 no yes * Deconfigure memory echo 0 > /sys/firmware/memory/memory16/config lsmem -o RANGE,SIZE,STATE,BLOCK,CONFIGURED,MEMMAP_ON_MEMORY RANGE SIZE STATE BLOCK CONFIGURED MEMMAP_ON_MEMORY 0x00000000-0x7fffffff 2G online 0-15 yes no 0x80000000-0xffffffff 2G offline 16-31 no yes * Enable memmap_on_memory and online it. (Deconfigure first) echo 0 > /sys/devices/system/memory/memory5/online echo 0 > /sys/firmware/memory/memory5/config lsmem -o RANGE,SIZE,STATE,BLOCK,CONFIGURED,MEMMAP_ON_MEMORY RANGE SIZE STATE BLOCK CONFIGURED MEMMAP_ON_MEMORY 0x00000000-0x27ffffff 640M online 0-4 yes no 0x28000000-0x2fffffff 128M offline 5 no no 0x30000000-0x7fffffff 1.3G online 6-15 yes no 0x80000000-0xffffffff 2G offline 16-31 no yes (Enable memmap_on_memory and online it) echo 1 > /sys/firmware/memory/memory5/memmap_on_memory echo 1 > /sys/firmware/memory/memory5/config echo 1 > /sys/devices/system/memory/memory5/online lsmem -o RANGE,SIZE,STATE,BLOCK,CONFIGURED,MEMMAP_ON_MEMORY RANGE SIZE STATE BLOCK CONFIGURED MEMMAP_ON_MEMORY 0x00000000-0x27ffffff 640M online 0-4 yes no 0x28000000-0x2fffffff 128M online 5 yes yes 0x30000000-0x7fffffff 1.3G online 6-15 yes no 0x80000000-0xffffffff 2G offline 16-31 no yes * Disable memmap_on_memory and online it. (Deconfigure first) echo 0 > /sys/devices/system/memory/memory5/online echo 0 > /sys/firmware/memory/memory5/config lsmem -o RANGE,SIZE,STATE,BLOCK,CONFIGURED,MEMMAP_ON_MEMORY RANGE SIZE STATE BLOCK CONFIGURED MEMMAP_ON_MEMORY 0x00000000-0x27ffffff 640M online 0-4 yes no 0x28000000-0x2fffffff 128M offline 5 no yes 0x30000000-0x7fffffff 1.3G online 6-15 yes no 0x80000000-0xffffffff 2G offline 16-31 no yes (Disable memmap_on_memory and online it) echo 0 > /sys/firmware/memory/memory5/memmap_on_memory echo 1 > /sys/firmware/memory/memory5/config echo 1 > /sys/devices/system/memory/memory5/online lsmem -o RANGE,SIZE,STATE,BLOCK,CONFIGURED,MEMMAP_ON_MEMORY RANGE SIZE STATE BLOCK CONFIGURED MEMMAP_ON_MEMORY 0x00000000-0x7fffffff 2G online 0-15 yes no 0x80000000-0xffffffff 2G offline 16-31 no yes * Userspace changes: lsmem/chmem tool is also changed to use the new interface. I will send it to util-linux soon. Patch 1 adds support for removal of boot-allocated memory blocks. Patch 2 provides option to dynamically configure and deconfigure memory with/without memmap_on_memory. Patch 3 removes MHP_OFFLINE_INACCESSIBLE from s390. The mhp flag was used to mark memory as not accessible until memory hotplug online phase begins. However, with patch 2, it is no longer essential. Memory can be brought to accessible state before adding memory, as the memory is added during runttime now instead of boottime. Patch 4 removes the MEM_PREPARE_ONLINE/MEM_FINISH_OFFLINE notifiers. It is no longer needed. Memory can be brought to accessible state before adding memory now, with runtime (de)configuration of memory. Note: The patches apply to the linux-next branch. v3: Thanks David * Avoid goto label in create_standby_sclp_mems(). * Use unsigned long instead of u64. * Add Acked-by. v2: Thanks David * Rename struct mblock/mblock_arg with struct sclp_mem/sclp_mem_arg. * Rename all mblocks/mblock references with sclp_mems/sclp_mem - structures, functions. * Rename create_online_mblock() with create_configured_sclp_mem(). * Rename config_mblock_show()/config_mblock_store() with config_sclp_mem_show()/config_sclp_mem_store(). * Remove contains_standby_increment() and sclp_mem_notifier. sclp mem state change is performed when adding/removing memory. sclp memory notifier - no longer needed with this patchset. * Recover sclp mem state when add_memory() fails. * Refactor and add function init_sclp_mem(). * Use unsigned long instead of unsigned long long. * Simplify and correct kobj handling. Thanks Heiko. ==================== Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2025-10-20Coccinelle-based conversion to use ->i_state accessorsMateusz Guzik
All places were patched by coccinelle with the default expecting that ->i_lock is held, afterwards entries got fixed up by hand to use unlocked variants as needed. The script: @@ expression inode, flags; @@ - inode->i_state & flags + inode_state_read(inode) & flags @@ expression inode, flags; @@ - inode->i_state &= ~flags + inode_state_clear(inode, flags) @@ expression inode, flag1, flag2; @@ - inode->i_state &= ~flag1 & ~flag2 + inode_state_clear(inode, flag1 | flag2) @@ expression inode, flags; @@ - inode->i_state |= flags + inode_state_set(inode, flags) @@ expression inode, flags; @@ - inode->i_state = flags + inode_state_assign(inode, flags) @@ expression inode, flags; @@ - flags = inode->i_state + flags = inode_state_read(inode) @@ expression inode, flags; @@ - READ_ONCE(inode->i_state) & flags + inode_state_read(inode) & flags Signed-off-by: Mateusz Guzik <mjguzik@gmail.com> Signed-off-by: Christian Brauner <brauner@kernel.org>
2025-10-20mm/mempolicy: Export memory policy symbolsShivank Garg
KVM guest_memfd wants to implement support for NUMA policies just like shmem already does using the shared policy infrastructure. As guest_memfd currently resides in KVM module code, we have to export the relevant symbols. In the future, guest_memfd might be moved to core-mm, at which point the symbols no longer would have to be exported. When/if that happens is still unclear. Acked-by: David Hildenbrand <david@redhat.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Shivank Garg <shivankg@amd.com> Tested-by: Ashish Kalra <ashish.kalra@amd.com> Link: https://lore.kernel.org/r/20250827175247.83322-6-shivankg@amd.com Signed-off-by: Sean Christopherson <seanjc@google.com>
2025-10-20mm/filemap: Extend __filemap_get_folio() to support NUMA memory policiesMatthew Wilcox
Extend __filemap_get_folio() to support NUMA memory policies by renaming the implementation to __filemap_get_folio_mpol() and adding a mempolicy parameter. The original function becomes a static inline wrapper that passes NULL for the mempolicy. This infrastructure will enable future support for NUMA-aware page cache allocations in guest_memfd memory backend KVM guests. Reviewed-by: Pankaj Gupta <pankaj.gupta@amd.com> Reviewed-by: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: David Hildenbrand <david@redhat.com> Signed-off-by: Shivank Garg <shivankg@amd.com> Tested-by: Ashish Kalra <ashish.kalra@amd.com> Link: https://lore.kernel.org/r/20250827175247.83322-5-shivankg@amd.com Signed-off-by: Sean Christopherson <seanjc@google.com>
2025-10-20mm/filemap: Add NUMA mempolicy support to filemap_alloc_folio()Matthew Wilcox
Add a mempolicy parameter to filemap_alloc_folio() to enable NUMA-aware page cache allocations. This will be used by upcoming changes to support NUMA policies in guest-memfd, where guest_memory need to be allocated NUMA policy specified by VMM. All existing users pass NULL maintaining current behavior. Reviewed-by: Pankaj Gupta <pankaj.gupta@amd.com> Reviewed-by: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: David Hildenbrand <david@redhat.com> Signed-off-by: Shivank Garg <shivankg@amd.com> Tested-by: Ashish Kalra <ashish.kalra@amd.com> Link: https://lore.kernel.org/r/20250827175247.83322-4-shivankg@amd.com Signed-off-by: Sean Christopherson <seanjc@google.com>
2025-10-16slab: reset slab->obj_ext when freeing and it is OBJEXTS_ALLOC_FAILHao Ge
If obj_exts allocation failed, slab->obj_exts is set to OBJEXTS_ALLOC_FAIL, But we do not clear it when freeing the slab. Since OBJEXTS_ALLOC_FAIL and MEMCG_DATA_OBJEXTS currently share the same bit position, during the release of the associated folio, a VM_BUG_ON_FOLIO() check in folio_memcg_kmem() is triggered because the OBJEXTS_ALLOC_FAIL flag was not cleared, causing it to be interpreted as a kmem folio (non-slab) with MEMCG_OBJEXTS_DATA flag set, which is invalid because MEMCG_OBJEXTS_DATA is supposed to be set only on slabs. Another problem that predates sharing the OBJEXTS_ALLOC_FAIL and MEMCG_DATA_OBJEXTS bits is that on configurations with is_check_pages_enabled(), the non-cleared bit in page->memcg_data will trigger a free_page_is_bad() failure "page still charged to cgroup" When freeing a slab, we clear slab->obj_exts if the obj_ext array has been successfully allocated. So let's clear it also when the allocation has failed. Fixes: 09c46563ff6d ("codetag: debug: introduce OBJEXTS_ALLOC_FAIL to mark failed slab_ext allocations") Fixes: 7612833192d5 ("slab: Reuse first bit for OBJEXTS_ALLOC_FAIL") Link: https://lore.kernel.org/all/20251015141642.700170-1-hao.ge@linux.dev/ Cc: <stable@vger.kernel.org> Signed-off-by: Hao Ge <gehao@kylinos.cn> Reviewed-by: Suren Baghdasaryan <surenb@google.com> Reviewed-by: Harry Yoo <harry.yoo@oracle.com> Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
2025-10-15mm: prevent poison consumption when splitting THPQiuxu Zhuo
When performing memory error injection on a THP (Transparent Huge Page) mapped to userspace on an x86 server, the kernel panics with the following trace. The expected behavior is to terminate the affected process instead of panicking the kernel, as the x86 Machine Check code can recover from an in-userspace #MC. mce: [Hardware Error]: CPU 0: Machine Check Exception: f Bank 3: bd80000000070134 mce: [Hardware Error]: RIP 10:<ffffffff8372f8bc> {memchr_inv+0x4c/0xf0} mce: [Hardware Error]: TSC afff7bbff88a ADDR 1d301b000 MISC 80 PPIN 1e741e77539027db mce: [Hardware Error]: PROCESSOR 0:d06d0 TIME 1758093249 SOCKET 0 APIC 0 microcode 80000320 mce: [Hardware Error]: Run the above through 'mcelog --ascii' mce: [Hardware Error]: Machine check: Data load in unrecoverable area of kernel Kernel panic - not syncing: Fatal local machine check The root cause of this panic is that handling a memory failure triggered by an in-userspace #MC necessitates splitting the THP. The splitting process employs a mechanism, implemented in try_to_map_unused_to_zeropage(), which reads the pages in the THP to identify zero-filled pages. However, reading the pages in the THP results in a second in-kernel #MC, occurring before the initial memory_failure() completes, ultimately leading to a kernel panic. See the kernel panic call trace on the two #MCs. First Machine Check occurs // [1] memory_failure() // [2] try_to_split_thp_page() split_huge_page() split_huge_page_to_list_to_order() __folio_split() // [3] remap_page() remove_migration_ptes() remove_migration_pte() try_to_map_unused_to_zeropage() // [4] memchr_inv() // [5] Second Machine Check occurs // [6] Kernel panic [1] Triggered by accessing a hardware-poisoned THP in userspace, which is typically recoverable by terminating the affected process. [2] Call folio_set_has_hwpoisoned() before try_to_split_thp_page(). [3] Pass the RMP_USE_SHARED_ZEROPAGE remap flag to remap_page(). [4] Try to map the unused THP to zeropage. [5] Re-access pages in the hw-poisoned THP in the kernel. [6] Triggered in-kernel, leading to a panic kernel. In Step[2], memory_failure() sets the poisoned flag on the page in the THP by TestSetPageHWPoison() before calling try_to_split_thp_page(). As suggested by David Hildenbrand, fix this panic by not accessing to the poisoned page in the THP during zeropage identification, while continuing to scan unaffected pages in the THP for possible zeropage mapping. This prevents a second in-kernel #MC that would cause kernel panic in Step[4]. Thanks to Andrew Zaborowski for his initial work on fixing this issue. Link: https://lkml.kernel.org/r/20251015064926.1887643-1-qiuxu.zhuo@intel.com Link: https://lkml.kernel.org/r/20251011075520.320862-1-qiuxu.zhuo@intel.com Fixes: b1f202060afe ("mm: remap unused subpages to shared zeropage when splitting isolated thp") Signed-off-by: Qiuxu Zhuo <qiuxu.zhuo@intel.com> Reported-by: Farrah Chen <farrah.chen@intel.com> Suggested-by: David Hildenbrand <david@redhat.com> Acked-by: David Hildenbrand <david@redhat.com> Tested-by: Farrah Chen <farrah.chen@intel.com> Tested-by: Qiuxu Zhuo <qiuxu.zhuo@intel.com> Acked-by: Lance Yang <lance.yang@linux.dev> Reviewed-by: Wei Yang <richard.weiyang@gmail.com> Acked-by: Zi Yan <ziy@nvidia.com> Reviewed-by: Miaohe Lin <linmiaohe@huawei.com> Cc: Barry Song <baohua@kernel.org> Cc: Dev Jain <dev.jain@arm.com> Cc: Jiaqi Yan <jiaqiyan@google.com> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: "Luck, Tony" <tony.luck@intel.com> Cc: Mariano Pache <npache@redhat.com> Cc: Miaohe Lin <linmiaohe@huawei.com> Cc: Naoya Horiguchi <nao.horiguchi@gmail.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-10-15mm: don't spin in add_stack_record when gfp flags don't allowAlexei Starovoitov
syzbot was able to find the following path: add_stack_record_to_list mm/page_owner.c:182 [inline] inc_stack_record_count mm/page_owner.c:214 [inline] __set_page_owner+0x2c3/0x4a0 mm/page_owner.c:333 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x240/0x2a0 mm/page_alloc.c:1851 prep_new_page mm/page_alloc.c:1859 [inline] get_page_from_freelist+0x21e4/0x22c0 mm/page_alloc.c:3858 alloc_pages_nolock_noprof+0x94/0x120 mm/page_alloc.c:7554 Don't spin in add_stack_record_to_list() when it is called from *_nolock() context. Link: https://lkml.kernel.org/r/CAADnVQK_8bNYEA7TJYgwTYR57=TTFagsvRxp62pFzS_z129eTg@mail.gmail.com Fixes: 97769a53f117 ("mm, bpf: Introduce try_alloc_pages() for opportunistic page allocation") Signed-off-by: Alexei Starovoitov <ast@kernel.org> Reported-by: syzbot+8259e1d0e3ae8ed0c490@syzkaller.appspotmail.com Reported-by: syzbot+665739f456b28f32b23d@syzkaller.appspotmail.com Acked-by: Vlastimil Babka <vbabka@suse.cz> Reviewed-by: Oscar Salvador <osalvador@suse.de> Cc: Brendan Jackman <jackmanb@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Zi Yan <ziy@nvidia.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-10-15mm/damon/sysfs: dealloc commit test ctx alwaysSeongJae Park
The damon_ctx for testing online DAMON parameters commit inputs is deallocated only when the test fails. This means memory is leaked for every successful online DAMON parameters commit. Fix the leak by always deallocating it. Link: https://lkml.kernel.org/r/20251003201455.41448-3-sj@kernel.org Fixes: 4c9ea539ad59 ("mm/damon/sysfs: validate user inputs from damon_sysfs_commit_input()") Signed-off-by: SeongJae Park <sj@kernel.org> Cc: <stable@vger.kernel.org> [6.15+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-10-15mm/damon/sysfs: catch commit test ctx alloc failureSeongJae Park
Patch series "mm/damon/sysfs: fix commit test damon_ctx [de]allocation". DAMON sysfs interface dynamically allocates and uses a damon_ctx object for testing if given inputs for online DAMON parameters update is valid. The object is being used without an allocation failure check, and leaked when the test succeeds. Fix the two bugs. This patch (of 2): The damon_ctx for testing online DAMON parameters commit inputs is used without its allocation failure check. This could result in an invalid memory access. Fix it by directly returning an error when the allocation failed. Link: https://lkml.kernel.org/r/20251003201455.41448-1-sj@kernel.org Link: https://lkml.kernel.org/r/20251003201455.41448-2-sj@kernel.org Fixes: 4c9ea539ad59 ("mm/damon/sysfs: validate user inputs from damon_sysfs_commit_input()") Signed-off-by: SeongJae Park <sj@kernel.org> Cc: <stable@vger.kernel.org> [6.15+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-10-14slab: fix clearing freelist in free_deferred_objects()Vlastimil Babka
defer_free() links pending objects using the slab's freelist offset which is fine as they are not free yet. free_deferred_objects() then clears this pointer to avoid confusing the debugging consistency checks that may be enabled for the cache. However, with CONFIG_SLAB_FREELIST_HARDENED, even the NULL pointer needs to be encoded appropriately using set_freepointer(), otherwise it's decoded as something else and triggers the consistency checks, as found by the kernel test robot. Use set_freepointer() to prevent the issue. Fixes: af92793e52c3 ("slab: Introduce kmalloc_nolock() and kfree_nolock().") Reported-and-tested-by: kernel test robot <oliver.sang@intel.com> Closes: https://lore.kernel.org/oe-lkp/202510101652.7921fdc6-lkp@intel.com Acked-by: Alexei Starovoitov <ast@kernel.org> Reviewed-by: Harry Yoo <harry.yoo@oracle.com> Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
2025-10-14mm/memory_hotplug: Remove MEM_PREPARE_ONLINE/MEM_FINISH_OFFLINE notifiersSumanth Korikkar
MEM_PREPARE_ONLINE/MEM_FINISH_OFFLINE memory notifiers were introduced to prepare the transition of memory to and from a physically accessible state. This enhancement was crucial for implementing the "memmap on memory" feature for s390. With introduction of dynamic (de)configuration of hotpluggable memory, memory can be brought to accessible state before add_memory(). Memory can be brought to inaccessible state before remove_memory(). Hence, there is no need of MEM_PREPARE_ONLINE/MEM_FINISH_OFFLINE memory notifiers anymore. This basically reverts commit c5f1e2d18909 ("mm/memory_hotplug: introduce MEM_PREPARE_ONLINE/MEM_FINISH_OFFLINE notifiers") Additionally, apply minor adjustments to the function parameters of move_pfn_range_to_zone() and mhp_supports_memmap_on_memory() to ensure compatibility with the latest branch. Acked-by: David Hildenbrand <david@redhat.com> Signed-off-by: Sumanth Korikkar <sumanthk@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2025-10-11Merge tag 'slab-for-6.18-rc1-hotfix' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/vbabka/slab Pull slab fix from Vlastimil Babka: "A NULL pointer deref hotfix" * tag 'slab-for-6.18-rc1-hotfix' of git://git.kernel.org/pub/scm/linux/kernel/git/vbabka/slab: slab: fix barn NULL pointer dereference on memoryless nodes
2025-10-11Merge tag 'mm-nonmm-stable-2025-10-10-15-03' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Pull more updates from Andrew Morton: "Just one series here - Mike Rappoport has taught KEXEC handover to preserve vmalloc allocations across handover" * tag 'mm-nonmm-stable-2025-10-10-15-03' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: lib/test_kho: use kho_preserve_vmalloc instead of storing addresses in fdt kho: add support for preserving vmalloc allocations kho: replace kho_preserve_phys() with kho_preserve_pages() kho: check if kho is finalized in __kho_preserve_order() MAINTAINERS, .mailmap: update Umang's email address
2025-10-11Merge tag 'mm-hotfixes-stable-2025-10-10-15-00' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Pull misc fixes from Andrew Morton: "7 hotfixes. All 7 are cc:stable and all 7 are for MM. All singletons, please see the changelogs for details" * tag 'mm-hotfixes-stable-2025-10-10-15-00' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: mm: hugetlb: avoid soft lockup when mprotect to large memory area fsnotify: pass correct offset to fsnotify_mmap_perm() mm/ksm: fix flag-dropping behavior in ksm_madvise mm/damon/vaddr: do not repeat pte_offset_map_lock() until success mm/rmap: fix soft-dirty and uffd-wp bit loss when remapping zero-filled mTHP subpage to shared zeropage mm/thp: fix MTE tag mismatch when replacing zero-filled subpages memcg: skip cgroup_file_notify if spinning is not allowed
2025-10-11slab: fix barn NULL pointer dereference on memoryless nodesVlastimil Babka
Phil reported a boot failure once sheaves become used in commits 59faa4da7cd4 ("maple_tree: use percpu sheaves for maple_node_cache") and 3accabda4da1 ("mm, vma: use percpu sheaves for vm_area_struct cache"): BUG: kernel NULL pointer dereference, address: 0000000000000040 #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page PGD 0 P4D 0 Oops: Oops: 0000 [#1] SMP NOPTI CPU: 21 UID: 0 PID: 818 Comm: kworker/u398:0 Not tainted 6.17.0-rc3.slab+ #5 PREEMPT(voluntary) Hardware name: Dell Inc. PowerEdge R7425/02MJ3T, BIOS 1.26.0 07/30/2025 RIP: 0010:__pcs_replace_empty_main+0x44/0x1d0 Code: ec 08 48 8b 46 10 48 8b 76 08 48 85 c0 74 0b 8b 48 18 85 c9 0f 85 e5 00 00 00 65 48 63 05 e4 ee 50 02 49 8b 84 c6 e0 00 00 00 <4c> 8b 68 40 4c 89 ef e8 b0 81 ff ff 48 89 c5 48 85 c0 74 1d 48 89 RSP: 0018:ffffd2d10950bdb0 EFLAGS: 00010246 RAX: 0000000000000000 RBX: ffff8a775dab74b0 RCX: 00000000ffffffff RDX: 0000000000000cc0 RSI: ffff8a6800804000 RDI: ffff8a680004e300 RBP: ffffd2d10950be40 R08: 0000000000000060 R09: ffffffffb9367388 R10: 00000000000149e8 R11: ffff8a6f87a38000 R12: 0000000000000cc0 R13: 0000000000000cc0 R14: ffff8a680004e300 R15: 00000000000000c0 FS: 0000000000000000(0000) GS:ffff8a77a3541000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000040 CR3: 0000000e1aa24000 CR4: 00000000003506f0 Call Trace: <TASK> ? srso_return_thunk+0x5/0x5f ? vm_area_alloc+0x1e/0x60 kmem_cache_alloc_noprof+0x4ec/0x5b0 vm_area_alloc+0x1e/0x60 create_init_stack_vma+0x26/0x210 alloc_bprm+0x139/0x200 kernel_execve+0x4a/0x140 call_usermodehelper_exec_async+0xd0/0x190 ? __pfx_call_usermodehelper_exec_async+0x10/0x10 ret_from_fork+0xf0/0x110 ? __pfx_call_usermodehelper_exec_async+0x10/0x10 ret_from_fork_asm+0x1a/0x30 </TASK> Modules linked in: CR2: 0000000000000040 ---[ end trace 0000000000000000 ]--- RIP: 0010:__pcs_replace_empty_main+0x44/0x1d0 Code: ec 08 48 8b 46 10 48 8b 76 08 48 85 c0 74 0b 8b 48 18 85 c9 0f 85 e5 00 00 00 65 48 63 05 e4 ee 50 02 49 8b 84 c6 e0 00 00 00 <4c> 8b 68 40 4c 89 ef e8 b0 81 ff ff 48 89 c5 48 85 c0 74 1d 48 89 RSP: 0018:ffffd2d10950bdb0 EFLAGS: 00010246 RAX: 0000000000000000 RBX: ffff8a775dab74b0 RCX: 00000000ffffffff RDX: 0000000000000cc0 RSI: ffff8a6800804000 RDI: ffff8a680004e300 RBP: ffffd2d10950be40 R08: 0000000000000060 R09: ffffffffb9367388 R10: 00000000000149e8 R11: ffff8a6f87a38000 R12: 0000000000000cc0 R13: 0000000000000cc0 R14: ffff8a680004e300 R15: 00000000000000c0 FS: 0000000000000000(0000) GS:ffff8a77a3541000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000040 CR3: 0000000e1aa24000 CR4: 00000000003506f0 Kernel panic - not syncing: Fatal exception Kernel Offset: 0x36a00000 from 0xffffffff81000000 (relocation range: 0xffffffff80000000-0xffffffffbfffffff) ---[ end Kernel panic - not syncing: Fatal exception ]--- And noted "this is an AMD EPYC 7401 with 8 NUMA nodes configured such that memory is only on 2 of them." # numactl --hardware available: 8 nodes (0-7) node 0 cpus: 0 8 16 24 32 40 48 56 64 72 80 88 node 0 size: 0 MB node 0 free: 0 MB node 1 cpus: 2 10 18 26 34 42 50 58 66 74 82 90 node 1 size: 31584 MB node 1 free: 30397 MB node 2 cpus: 4 12 20 28 36 44 52 60 68 76 84 92 node 2 size: 0 MB node 2 free: 0 MB node 3 cpus: 6 14 22 30 38 46 54 62 70 78 86 94 node 3 size: 0 MB node 3 free: 0 MB node 4 cpus: 1 9 17 25 33 41 49 57 65 73 81 89 node 4 size: 0 MB node 4 free: 0 MB node 5 cpus: 3 11 19 27 35 43 51 59 67 75 83 91 node 5 size: 32214 MB node 5 free: 31625 MB node 6 cpus: 5 13 21 29 37 45 53 61 69 77 85 93 node 6 size: 0 MB node 6 free: 0 MB node 7 cpus: 7 15 23 31 39 47 55 63 71 79 87 95 node 7 size: 0 MB node 7 free: 0 MB Linus decoded the stacktrace to get_barn() and get_node() and determined that kmem_cache->node[numa_mem_id()] is NULL. The problem is due to a wrong assumption that memoryless nodes only exist on systems with CONFIG_HAVE_MEMORYLESS_NODES, where numa_mem_id() points to the nearest node that has memory. SLUB has been allocating its kmem_cache_node structures only on nodes with memory and so it does with struct node_barn. For kmem_cache_node, get_partial_node() checks if get_node() result is not NULL, which I assumed was for protection from a bogus node id passed to kmalloc_node() but apparently it's also for systems where numa_mem_id() (used when no specific node is given) might return a memoryless node. Fix the sheaves code the same way by checking the result of get_node() and bailing out if it's NULL. Note that cpus on such memoryless nodes will have degraded sheaves performance, which can be improved later, preferably by making numa_mem_id() work properly on such systems. Fixes: 2d517aa09bbc ("slab: add opt-in caching layer of percpu sheaves") Reported-and-tested-by: Phil Auld <pauld@redhat.com> Closes: https://lore.kernel.org/all/20251010151116.GA436967@pauld.westford.csb/ Analyzed-by: Linus Torvalds <torvalds@linux-foundation.org> Link: https://lore.kernel.org/all/CAHk-%3Dwg1xK%2BBr%3DFJ5QipVhzCvq7uQVPt5Prze6HDhQQ%3DQD_BcQ@mail.gmail.com/ Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
2025-10-09Merge tag 'slab-for-6.18-rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/vbabka/slab Pull slab fixes from Vlastimil Babka: - Fixes for several corner cases in error paths and debugging options, related to the new kmalloc_nolock() functionality (Kuniyuki Iwashima, Ran Xiaokai) * tag 'slab-for-6.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/vbabka/slab: slub: Don't call lockdep_unregister_key() for immature kmem_cache. slab: Fix using this_cpu_ptr() in preemptible context slab: Add allow_spin check to eliminate kmemleak warnings
2025-10-07mm: hugetlb: avoid soft lockup when mprotect to large memory areaYang Shi
When calling mprotect() to a large hugetlb memory area in our customer's workload (~300GB hugetlb memory), soft lockup was observed: watchdog: BUG: soft lockup - CPU#98 stuck for 23s! [t2_new_sysv:126916] CPU: 98 PID: 126916 Comm: t2_new_sysv Kdump: loaded Not tainted 6.17-rc7 Hardware name: GIGACOMPUTING R2A3-T40-AAV1/Jefferson CIO, BIOS 5.4.4.1 07/15/2025 pstate: 20400009 (nzCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--) pc : mte_clear_page_tags+0x14/0x24 lr : mte_sync_tags+0x1c0/0x240 sp : ffff80003150bb80 x29: ffff80003150bb80 x28: ffff00739e9705a8 x27: 0000ffd2d6a00000 x26: 0000ff8e4bc00000 x25: 00e80046cde00f45 x24: 0000000000022458 x23: 0000000000000000 x22: 0000000000000004 x21: 000000011b380000 x20: ffff000000000000 x19: 000000011b379f40 x18: 0000000000000000 x17: 0000000000000000 x16: 0000000000000000 x15: 0000000000000000 x14: 0000000000000000 x13: 0000000000000000 x12: 0000000000000000 x11: 0000000000000000 x10: 0000000000000000 x9 : ffffc875e0aa5e2c x8 : 0000000000000000 x7 : 0000000000000000 x6 : 0000000000000000 x5 : fffffc01ce7a5c00 x4 : 00000000046cde00 x3 : fffffc0000000000 x2 : 0000000000000004 x1 : 0000000000000040 x0 : ffff0046cde7c000 Call trace:   mte_clear_page_tags+0x14/0x24   set_huge_pte_at+0x25c/0x280   hugetlb_change_protection+0x220/0x430   change_protection+0x5c/0x8c   mprotect_fixup+0x10c/0x294   do_mprotect_pkey.constprop.0+0x2e0/0x3d4   __arm64_sys_mprotect+0x24/0x44   invoke_syscall+0x50/0x160   el0_svc_common+0x48/0x144   do_el0_svc+0x30/0xe0   el0_svc+0x30/0xf0   el0t_64_sync_handler+0xc4/0x148   el0t_64_sync+0x1a4/0x1a8 Soft lockup is not triggered with THP or base page because there is cond_resched() called for each PMD size. Although the soft lockup was triggered by MTE, it should be not MTE specific. The other processing which takes long time in the loop may trigger soft lockup too. So add cond_resched() for hugetlb to avoid soft lockup. Link: https://lkml.kernel.org/r/20250929202402.1663290-1-yang@os.amperecomputing.com Fixes: 8f860591ffb2 ("[PATCH] Enable mprotect on huge pages") Signed-off-by: Yang Shi <yang@os.amperecomputing.com> Tested-by: Carl Worth <carl@os.amperecomputing.com> Reviewed-by: Christoph Lameter (Ampere) <cl@gentwo.org> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: David Hildenbrand <david@redhat.com> Acked-by: Oscar Salvador <osalvador@suse.de> Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com> Reviewed-by: Dev Jain <dev.jain@arm.com> Cc: Muchun Song <muchun.song@linux.dev> Cc: Will Deacon <will@kernel.org> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-10-07fsnotify: pass correct offset to fsnotify_mmap_perm()Ryan Roberts
fsnotify_mmap_perm() requires a byte offset for the file about to be mmap'ed. But it is called from vm_mmap_pgoff(), which has a page offset. Previously the conversion was done incorrectly so let's fix it, being careful not to overflow on 32-bit platforms. Discovered during code review. Link: https://lkml.kernel.org/r/20251003155238.2147410-1-ryan.roberts@arm.com Fixes: 066e053fe208 ("fsnotify: add pre-content hooks on mmap()") Signed-off-by: Ryan Roberts <ryan.roberts@arm.com> Reviewed-by: Kiryl Shutsemau <kas@kernel.org> Cc: Amir Goldstein <amir73il@gmail.com> Cc: David Hildenbrand <david@redhat.com> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-10-07mm/damon/vaddr: do not repeat pte_offset_map_lock() until successSeongJae Park
DAMON's virtual address space operation set implementation (vaddr) calls pte_offset_map_lock() inside the page table walk callback function. This is for reading and writing page table accessed bits. If pte_offset_map_lock() fails, it retries by returning the page table walk callback function with ACTION_AGAIN. pte_offset_map_lock() can continuously fail if the target is a pmd migration entry, though. Hence it could cause an infinite page table walk if the migration cannot be done until the page table walk is finished. This indeed caused a soft lockup when CPU hotplugging and DAMON were running in parallel. Avoid the infinite loop by simply not retrying the page table walk. DAMON is promising only a best-effort accuracy, so missing access to such pages is no problem. Link: https://lkml.kernel.org/r/20250930004410.55228-1-sj@kernel.org Fixes: 7780d04046a2 ("mm/pagewalkers: ACTION_AGAIN if pte_offset_map_lock() fails") Signed-off-by: SeongJae Park <sj@kernel.org> Reported-by: Xinyu Zheng <zhengxinyu6@huawei.com> Closes: https://lore.kernel.org/20250918030029.2652607-1-zhengxinyu6@huawei.com Acked-by: Hugh Dickins <hughd@google.com> Cc: <stable@vger.kernel.org> [6.5+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-10-07mm/rmap: fix soft-dirty and uffd-wp bit loss when remapping zero-filled mTHP ↵Lance Yang
subpage to shared zeropage When splitting an mTHP and replacing a zero-filled subpage with the shared zeropage, try_to_map_unused_to_zeropage() currently drops several important PTE bits. For userspace tools like CRIU, which rely on the soft-dirty mechanism for incremental snapshots, losing the soft-dirty bit means modified pages are missed, leading to inconsistent memory state after restore. As pointed out by David, the more critical uffd-wp bit is also dropped. This breaks the userfaultfd write-protection mechanism, causing writes to be silently missed by monitoring applications, which can lead to data corruption. Preserve both the soft-dirty and uffd-wp bits from the old PTE when creating the new zeropage mapping to ensure they are correctly tracked. Link: https://lkml.kernel.org/r/20250930081040.80926-1-lance.yang@linux.dev Fixes: b1f202060afe ("mm: remap unused subpages to shared zeropage when splitting isolated thp") Signed-off-by: Lance Yang <lance.yang@linux.dev> Suggested-by: David Hildenbrand <david@redhat.com> Suggested-by: Dev Jain <dev.jain@arm.com> Acked-by: David Hildenbrand <david@redhat.com> Reviewed-by: Dev Jain <dev.jain@arm.com> Acked-by: Zi Yan <ziy@nvidia.com> Reviewed-by: Liam R. Howlett <Liam.Howlett@oracle.com> Reviewed-by: Harry Yoo <harry.yoo@oracle.com> Cc: Alistair Popple <apopple@nvidia.com> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Barry Song <baohua@kernel.org> Cc: Byungchul Park <byungchul@sk.com> Cc: Gregory Price <gourry@gourry.net> Cc: "Huang, Ying" <ying.huang@linux.alibaba.com> Cc: Jann Horn <jannh@google.com> Cc: Joshua Hahn <joshua.hahnjy@gmail.com> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Mariano Pache <npache@redhat.com> Cc: Mathew Brost <matthew.brost@intel.com> Cc: Peter Xu <peterx@redhat.com> Cc: Rakie Kim <rakie.kim@sk.com> Cc: Rik van Riel <riel@surriel.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Usama Arif <usamaarif642@gmail.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Yu Zhao <yuzhao@google.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-10-07mm/thp: fix MTE tag mismatch when replacing zero-filled subpagesLance Yang
When both THP and MTE are enabled, splitting a THP and replacing its zero-filled subpages with the shared zeropage can cause MTE tag mismatch faults in userspace. Remapping zero-filled subpages to the shared zeropage is unsafe, as the zeropage has a fixed tag of zero, which may not match the tag expected by the userspace pointer. KSM already avoids this problem by using memcmp_pages(), which on arm64 intentionally reports MTE-tagged pages as non-identical to prevent unsafe merging. As suggested by David[1], this patch adopts the same pattern, replacing the memchr_inv() byte-level check with a call to pages_identical(). This leverages existing architecture-specific logic to determine if a page is truly identical to the shared zeropage. Having both the THP shrinker and KSM rely on pages_identical() makes the design more future-proof, IMO. Instead of handling quirks in generic code, we just let the architecture decide what makes two pages identical. [1] https://lore.kernel.org/all/ca2106a3-4bb2-4457-81af-301fd99fbef4@redhat.com Link: https://lkml.kernel.org/r/20250922021458.68123-1-lance.yang@linux.dev Fixes: b1f202060afe ("mm: remap unused subpages to shared zeropage when splitting isolated thp") Signed-off-by: Lance Yang <lance.yang@linux.dev> Reported-by: Qun-wei Lin <Qun-wei.Lin@mediatek.com> Closes: https://lore.kernel.org/all/a7944523fcc3634607691c35311a5d59d1a3f8d4.camel@mediatek.com Suggested-by: David Hildenbrand <david@redhat.com> Acked-by: Zi Yan <ziy@nvidia.com> Acked-by: David Hildenbrand <david@redhat.com> Acked-by: Usama Arif <usamaarif642@gmail.com> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Reviewed-by: Wei Yang <richard.weiyang@gmail.com> Cc: Alistair Popple <apopple@nvidia.com> Cc: andrew.yang <andrew.yang@mediatek.com> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Barry Song <baohua@kernel.org> Cc: Byungchul Park <byungchul@sk.com> Cc: Charlie Jenkins <charlie@rivosinc.com> Cc: Chinwen Chang <chinwen.chang@mediatek.com> Cc: Dev Jain <dev.jain@arm.com> Cc: Domenico Cerasuolo <cerasuolodomenico@gmail.com> Cc: Gregory Price <gourry@gourry.net> Cc: "Huang, Ying" <ying.huang@linux.alibaba.com> Cc: Hugh Dickins <hughd@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Joshua Hahn <joshua.hahnjy@gmail.com> Cc: Kairui Song <ryncsn@gmail.com> Cc: Kalesh Singh <kaleshsingh@google.com> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Mariano Pache <npache@redhat.com> Cc: Mathew Brost <matthew.brost@intel.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Mike Rapoport <rppt@kernel.org> Cc: Palmer Dabbelt <palmer@rivosinc.com> Cc: Rakie Kim <rakie.kim@sk.com> Cc: Rik van Riel <riel@surriel.com> Cc: Roman Gushchin <roman.gushchin@linux.dev> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Samuel Holland <samuel.holland@sifive.com> Cc: Shakeel Butt <shakeel.butt@linux.dev> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Yu Zhao <yuzhao@google.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-10-07memcg: skip cgroup_file_notify if spinning is not allowedShakeel Butt
Generally memcg charging is allowed from all the contexts including NMI where even spinning on spinlock can cause locking issues. However one call chain was missed during the addition of memcg charging from any context support. That is try_charge_memcg() -> memcg_memory_event() -> cgroup_file_notify(). The possible function call tree under cgroup_file_notify() can acquire many different spin locks in spinning mode. Some of them are cgroup_file_kn_lock, kernfs_notify_lock, pool_workqeue's lock. So, let's just skip cgroup_file_notify() from memcg charging if the context does not allow spinning. Alternative approach was also explored where instead of skipping cgroup_file_notify(), we defer the memcg event processing to irq_work [1]. However it adds complexity and it was decided to keep things simple until we need more memcg events with !allow_spinning requirement. Link: https://lore.kernel.org/all/5qi2llyzf7gklncflo6gxoozljbm4h3tpnuv4u4ej4ztysvi6f@x44v7nz2wdzd/ [1] Link: https://lkml.kernel.org/r/20250922220203.261714-1-shakeel.butt@linux.dev Fixes: 3ac4638a734a ("memcg: make memcg_rstat_updated nmi safe") Signed-off-by: Shakeel Butt <shakeel.butt@linux.dev> Acked-by: Michal Hocko <mhocko@suse.com> Closes: https://lore.kernel.org/all/20250905061919.439648-1-yepeilin@google.com/ Cc: Alexei Starovoitov <ast@kernel.org> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Kumar Kartikeya Dwivedi <memxor@gmail.com> Cc: Muchun Song <muchun.song@linux.dev> Cc: Peilin Ye <yepeilin@google.com> Cc: Roman Gushchin <roman.gushchin@linux.dev> Cc: Tejun Heo <tj@kernel.org> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-10-07kho: replace kho_preserve_phys() with kho_preserve_pages()Mike Rapoport (Microsoft)
to make it clear that KHO operates on pages rather than on a random physical address. The kho_preserve_pages() will be also used in upcoming support for vmalloc preservation. Link: https://lkml.kernel.org/r/20250921054458.4043761-3-rppt@kernel.org Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org> Reviewed-by: Pratyush Yadav <pratyush@kernel.org> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Cc: Alexander Graf <graf@amazon.com> Cc: Baoquan He <bhe@redhat.com> Cc: Changyuan Lyu <changyuanl@google.com> Cc: Chris Li <chrisl@kernel.org> Cc: Pasha Tatashin <pasha.tatashin@soleen.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-10-07Merge tag 'dma-mapping-6.18-2025-10-07' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/mszyprowski/linux Pull dma-mapping fixes from Marek Szyprowski: "Two small fixes for the recently performed code refactoring (Shigeru Yoshida) and missing handling of direction parameter in DMA debug code (Petr Tesarik)" * tag 'dma-mapping-6.18-2025-10-07' of git://git.kernel.org/pub/scm/linux/kernel/git/mszyprowski/linux: dma-mapping: fix direction in dma_alloc direction traces kmsan: fix kmsan_handle_dma() to avoid false positives
2025-10-07slub: Don't call lockdep_unregister_key() for immature kmem_cache.Kuniyuki Iwashima
syzbot reported the lockdep splat below in __kmem_cache_release(). [0] The problem is that __kmem_cache_release() could be called from do_kmem_cache_create() before init_kmem_cache_cpus() registers the lockdep key. Let's perform lockdep_unregister_key() only when init_kmem_cache_cpus() has been done, which we can determine by checking s->cpu_slab [0]: WARNING: CPU: 1 PID: 6128 at kernel/locking/lockdep.c:6606 lockdep_unregister_key+0x2ca/0x310 kernel/locking/lockdep.c:6606 Modules linked in: CPU: 1 UID: 0 PID: 6128 Comm: syz.4.21 Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 RIP: 0010:lockdep_unregister_key+0x2ca/0x310 kernel/locking/lockdep.c:6606 Code: 50 e4 0f 48 3b 44 24 10 0f 84 26 fe ff ff e8 bd cd 17 09 e8 e8 ce 17 09 41 f7 c7 00 02 00 00 74 bd fb 40 84 ed 75 bc eb cd 90 <0f> 0b 90 e9 19 ff ff ff 90 0f 0b 90 e9 2a ff ff ff 48 c7 c7 d0 ac RSP: 0018:ffffc90003e870d0 EFLAGS: 00010002 RAX: eb1525397f5bdf00 RBX: ffff88803c121148 RCX: 1ffff920007d0dfc RDX: 0000000000000000 RSI: ffffffff8acb1500 RDI: ffffffff8b1dd0e0 RBP: 00000000ffffffea R08: ffffffff8eb5aa37 R09: 1ffffffff1d6b546 R10: dffffc0000000000 R11: fffffbfff1d6b547 R12: 0000000000000000 R13: ffff88814d1b8900 R14: 0000000000000000 R15: 0000000000000203 FS: 00007f773f75e6c0(0000) GS:ffff88812712f000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ffdaea3af52 CR3: 000000003a5ca000 CR4: 00000000003526f0 Call Trace: <TASK> __kmem_cache_release+0xe3/0x1e0 mm/slub.c:7696 do_kmem_cache_create+0x74e/0x790 mm/slub.c:8575 create_cache mm/slab_common.c:242 [inline] __kmem_cache_create_args+0x1ce/0x330 mm/slab_common.c:340 nfsd_file_cache_init+0x1d6/0x530 fs/nfsd/filecache.c:816 nfsd_startup_generic fs/nfsd/nfssvc.c:282 [inline] nfsd_startup_net fs/nfsd/nfssvc.c:377 [inline] nfsd_svc+0x393/0x900 fs/nfsd/nfssvc.c:786 nfsd_nl_threads_set_doit+0x84a/0x960 fs/nfsd/nfsctl.c:1639 genl_family_rcv_msg_doit+0x212/0x300 net/netlink/genetlink.c:1115 genl_family_rcv_msg net/netlink/genetlink.c:1195 [inline] genl_rcv_msg+0x60e/0x790 net/netlink/genetlink.c:1210 netlink_rcv_skb+0x208/0x470 net/netlink/af_netlink.c:2552 genl_rcv+0x28/0x40 net/netlink/genetlink.c:1219 netlink_unicast_kernel net/netlink/af_netlink.c:1320 [inline] netlink_unicast+0x846/0xa10 net/netlink/af_netlink.c:1346 netlink_sendmsg+0x805/0xb30 net/netlink/af_netlink.c:1896 sock_sendmsg_nosec net/socket.c:727 [inline] __sock_sendmsg+0x219/0x270 net/socket.c:742 ____sys_sendmsg+0x508/0x820 net/socket.c:2630 ___sys_sendmsg+0x21f/0x2a0 net/socket.c:2684 __sys_sendmsg net/socket.c:2716 [inline] __do_sys_sendmsg net/socket.c:2721 [inline] __se_sys_sendmsg net/socket.c:2719 [inline] __x64_sys_sendmsg+0x1a1/0x260 net/socket.c:2719 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f77400eeec9 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f773f75e038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007f7740345fa0 RCX: 00007f77400eeec9 RDX: 0000000000008004 RSI: 0000200000000180 RDI: 0000000000000006 RBP: 00007f7740171f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f7740346038 R14: 00007f7740345fa0 R15: 00007ffce616f8d8 </TASK> [alexei.starovoitov@gmail.com: simplify the fix] Link: https://lore.kernel.org/all/20251007052534.2776661-1-kuniyu@google.com/ Fixes: 83382af9ddc3 ("slab: Make slub local_(try)lock more precise for LOCKDEP") Reported-by: syzbot+a6f4d69b9b23404bbabf@syzkaller.appspotmail.com Closes: https://lore.kernel.org/all/68e4a3d1.a00a0220.298cc0.0471.GAE@google.com/ Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com> Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
2025-10-06slab: Fix using this_cpu_ptr() in preemptible contextRan Xiaokai
defer_free() maybe called in preemptible context, this will trigger the below warning message: BUG: using smp_processor_id() in preemptible [00000000] code: swapper/0/1 caller is defer_free+0x1b/0x60 Call Trace: <TASK> dump_stack_lvl+0xac/0xc0 check_preemption_disabled+0xbe/0xe0 defer_free+0x1b/0x60 kfree_nolock+0x1eb/0x2b0 alloc_slab_obj_exts+0x356/0x390 __alloc_tagging_slab_alloc_hook+0xa0/0x300 __kmalloc_cache_noprof+0x1c4/0x5c0 __set_page_owner+0x10d/0x1c0 post_alloc_hook+0x84/0xf0 get_page_from_freelist+0x73b/0x1380 __alloc_frozen_pages_noprof+0x110/0x2c0 alloc_pages_mpol+0x44/0x140 alloc_slab_page+0xac/0x150 allocate_slab+0x78/0x3a0 ___slab_alloc+0x76b/0xed0 __slab_alloc.constprop.0+0x5a/0xb0 __kmalloc_noprof+0x3dc/0x6d0 __list_lru_init+0x6c/0x210 alloc_super+0x3b6/0x470 sget_fc+0x5f/0x3a0 get_tree_nodev+0x27/0x90 vfs_get_tree+0x26/0xc0 vfs_kern_mount.part.0+0xb6/0x140 kern_mount+0x24/0x40 init_pipe_fs+0x4f/0x70 do_one_initcall+0x62/0x2e0 kernel_init_freeable+0x25b/0x4b0 kernel_init+0x1a/0x1c0 ret_from_fork+0x290/0x2e0 ret_from_fork_asm+0x11/0x20 </TASK> Disable preemption in defer_free() and also defer_deactivate_slab() to make it safe. [vbabka@suse.cz: disable preemption instead of using raw_cpu_ptr() per the discussion ] Fixes: af92793e52c3 ("slab: Introduce kmalloc_nolock() and kfree_nolock().") Signed-off-by: Ran Xiaokai <ran.xiaokai@zte.com.cn> Link: https://lore.kernel.org/r/20250930083402.782927-1-ranxiaokai627@163.com Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
2025-10-05Merge tag 'mm-stable-2025-10-03-16-49' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Pull more MM updates from Andrew Morton: "Only two patch series in this pull request: - "mm/memory_hotplug: fixup crash during uevent handling" from Hannes Reinecke fixes a race that was causing udev to trigger a crash in the memory hotplug code - "mm_slot: following fixup for usage of mm_slot_entry()" from Wei Yang adds some touchups to the just-merged mm_slot changes" * tag 'mm-stable-2025-10-03-16-49' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: mm/khugepaged: use KMEM_CACHE() mm/ksm: cleanup mm_slot_entry() invocation Documentation/mm: drop pxx_mkdevmap() descriptions from page table helpers mm: clean up is_guard_pte_marker() drivers/base: move memory_block_add_nid() into the caller mm/memory_hotplug: activate node before adding new memory blocks drivers/base/memory: add node id parameter to add_memory_block()
2025-10-04Merge tag 'memblock-v6.18-rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/rppt/memblock Pull mm-init update from Mike Rapoport: "Simplify deferred initialization of struct pages Refactor and simplify deferred initialization of the memory map. Beside the negative diffstat it gives 3ms (55ms vs 58ms) reduction in the initialization of deferred pages on single node system with 64GiB of RAM" * tag 'memblock-v6.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rppt/memblock: memblock: drop for_each_free_mem_pfn_range_in_zone_from() mm/mm_init: drop deferred_init_maxorder() mm/mm_init: deferred_init_memmap: use a job per zone mm/mm_init: use deferred_init_memmap_chunk() in deferred_grow_zone()
2025-10-03Merge tag 'dma-mapping-6.18-2025-09-30' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/mszyprowski/linux Pull dma-mapping updates from Marek Szyprowski: - Refactoring of DMA mapping API to physical addresses as the primary interface instead of page+offset parameters This gets much closer to Matthew Wilcox's long term wish for struct-pageless IO to cacheable DRAM and is supporting memdesc project which seeks to substantially transform how struct page works. An advantage of this approach is the possibility of introducing DMA_ATTR_MMIO, which covers existing 'dma_map_resource' flow in the common paths, what in turn lets to use recently introduced dma_iova_link() API to map PCI P2P MMIO without creating struct page Developped by Leon Romanovsky and Jason Gunthorpe - Minor clean-up by Petr Tesarik and Qianfeng Rong * tag 'dma-mapping-6.18-2025-09-30' of git://git.kernel.org/pub/scm/linux/kernel/git/mszyprowski/linux: kmsan: fix missed kmsan_handle_dma() signature conversion mm/hmm: properly take MMIO path mm/hmm: migrate to physical address-based DMA mapping API dma-mapping: export new dma_*map_phys() interface xen: swiotlb: Open code map_resource callback dma-mapping: implement DMA_ATTR_MMIO for dma_(un)map_page_attrs() kmsan: convert kmsan_handle_dma to use physical addresses dma-mapping: convert dma_direct_*map_page to be phys_addr_t based iommu/dma: implement DMA_ATTR_MMIO for iommu_dma_(un)map_phys() iommu/dma: rename iommu_dma_*map_page to iommu_dma_*map_phys dma-mapping: rename trace_dma_*map_page to trace_dma_*map_phys dma-debug: refactor to use physical addresses for page mapping iommu/dma: implement DMA_ATTR_MMIO for dma_iova_link(). dma-mapping: introduce new DMA attribute to indicate MMIO memory swiotlb: Remove redundant __GFP_NOWARN dma-direct: clean up the logic in __dma_direct_alloc_pages()
2025-10-03mm/khugepaged: use KMEM_CACHE()Wei Yang
We got some late review commits during review of commit b4c9ffb54b32 ("mm/khugepaged: remove definition of struct khugepaged_mm_slot"). No need to keep the old cache name "khugepaged_mm_slot", let's simply use KMEM_CACHE(). Link: https://lkml.kernel.org/r/20251001091900.20041-3-richard.weiyang@gmail.com Fixes: b4c9ffb54b32 ("mm/khugepaged: remove definition of struct khugepaged_mm_slot") Signed-off-by: Wei Yang <richard.weiyang@gmail.com> Acked-by: Lance Yang <lance.yang@linux.dev> Reviewed-by: Dev Jain <dev.jain@arm.com> Acked-by: David Hildenbrand <david@redhat.com> Acked-by: Zi Yan <ziy@nvidia.com> Reviewed-by: Raghavendra K T <raghavendra.kt@amd.com> Cc: Kiryl Shutsemau <kirill@shutemov.name> Cc: xu xin <xu.xin16@zte.com.cn> Cc: SeongJae Park <sj@kernel.org> Cc: Nico Pache <npache@redhat.com> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Barry Song <baohua@kernel.org> Cc: Chengming Zhou <chengming.zhou@linux.dev> Cc: Dan Carpenter <dan.carpenter@linaro.org> Cc: Kiryl Shutsemau <kas@kernel.org> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-10-03mm/ksm: cleanup mm_slot_entry() invocationWei Yang
Patch series "mm_slot: following fixup for usage of mm_slot_entry()", v2. We got some late review commits during review of "mm_slot: fix the usage of mm_slot_entry()" in [1]. This patch (of 2): We got some late review commits during review of commit 08498be43ee6 ("mm/ksm: get mm_slot by mm_slot_entry() when slot is !NULL"). Let's reduce the indentation level and make the code easier to follow by using gotos to a new label. Link: https://lkml.kernel.org/r/20251001091900.20041-1-richard.weiyang@gmail.com Link: https://lkml.kernel.org/r/20251001091900.20041-2-richard.weiyang@gmail.com Link: https://lkml.kernel.org/r/20250927004539.19308-1-richard.weiyang@gmail.com [1] Fixes: 08498be43ee6 ("mm/ksm: get mm_slot by mm_slot_entry() when slot is !NULL") Signed-off-by: Wei Yang <richard.weiyang@gmail.com> Reviewed-by: Dev Jain <dev.jain@arm.com> Acked-by: David Hildenbrand <david@redhat.com> Acked-by: Kiryl Shutsemau <kas@kernel.org> Acked-by: Zi Yan <ziy@nvidia.com> Cc: Lance Yang <lance.yang@linux.dev> Cc: xu xin <xu.xin16@zte.com.cn> Cc: Dan Carpenter <dan.carpenter@linaro.org> Cc: Chengming Zhou <chengming.zhou@linux.dev> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Barry Song <baohua@kernel.org> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Mariano Pache <npache@redhat.com> Cc: Raghavendra K T <raghavendra.kt@amd.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Kiryl Shutsemau <kirill@shutemov.name> Cc: SeongJae Park <sj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-10-03mm: clean up is_guard_pte_marker()Lance Yang
Let's simplify the implementation. The current code is redundant as it effectively expands to: is_swap_pte(pte) && is_pte_marker_entry(...) && // from is_pte_marker() is_pte_marker_entry(...) // from is_guard_swp_entry() While a modern compiler could likely optimize this away, let's have clean code and not rely on it. Link: https://lkml.kernel.org/r/20250924045830.3817-1-lance.yang@linux.dev Signed-off-by: Lance Yang <lance.yang@linux.dev> Reviewed-by: Wei Yang <richard.weiyang@gmail.com> Reviewed-by: Zi Yan <ziy@nvidia.com> Acked-by: David Hildenbrand <david@redhat.com> Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Reviewed-by: Dev Jain <dev.jain@arm.com> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Barry Song <baohua@kernel.org> Cc: Hugh Dickins <hughd@google.com> Cc: Kairui Song <kasong@tencent.com> Cc: "Kirill A. Shutemov" <kirill@shutemov.name> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Mariano Pache <npache@redhat.com> Cc: Mika Penttilä <mpenttil@redhat.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-10-03mm/memory_hotplug: activate node before adding new memory blocksHannes Reinecke
The sysfs attributes for memory blocks require the node ID to be set and initialized, so move the node activation before adding new memory blocks. This also has the nice side effect that the BUG_ON() can be converted into a WARN_ON() as we now can handle registration errors. Link: https://lkml.kernel.org/r/20250729064637.51662-3-hare@kernel.org Fixes: b9ff036082cd ("mm/memory_hotplug.c: make add_memory_resource use __try_online_node") Signed-off-by: Hannes Reinecke <hare@kernel.org> Acked-by: David Hildenbrand <david@redhat.com> Acked-by: Oscar Salvador <osalvador@suse.de> Reviewed-by: Donet Tom <donettom@linux.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>