December 2022 - Linux-stable-mirror

FAILED: patch "[PATCH] mm/khugepaged: fix GUP-fast interaction by sending IPI" failed to apply to 5.10-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 5.10-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. Possible dependencies: 2ba99c5e0881 ("mm/khugepaged: fix GUP-fast interaction by sending IPI") 8d3c106e19e8 ("mm/khugepaged: take the right locks for page table retraction") 34488399fa08 ("mm/madvise: add file and shmem support to MADV_COLLAPSE") 58ac9a8993a1 ("mm/khugepaged: attempt to map file/shmem-backed pte-mapped THPs by pmds") 780a4b6fb865 ("mm/khugepaged: check compound_order() in collapse_pte_mapped_thp()") b26e27015ec9 ("mm: thp: convert to use common struct mm_slot") 685405020b9f ("mm/khugepaged: stop using vma linked list") 7d2c4385c341 ("mm/khugepaged: rename prefix of shared collapse functions") 7d8faaf15545 ("mm/madvise: introduce MADV_COLLAPSE sync hugepage collapse") 507228044236 ("mm/khugepaged: record SCAN_PMD_MAPPED when scan_pmd() finds hugepage") a7f4e6e4c47c ("mm/thp: add flag to enforce sysfs THP in hugepage_vma_check()") 50ad2f24b3b4 ("mm/khugepaged: propagate enum scan_result codes back to callers") 9710a78ab2ae ("mm/khugepaged: dedup and simplify hugepage alloc and charging") 34d6b470ab9c ("mm/khugepaged: add struct collapse_control") c6a7f445a272 ("mm: khugepaged: don't carry huge page to the next loop for !CONFIG_NUMA") 1064026bab9f ("mm: khugepaged: reorg some khugepaged helpers") 7da4e2cb8b1f ("mm: thp: kill __transhuge_page_enabled()") 9fec51689ff6 ("mm: thp: kill transparent_hugepage_active()") f707fa493784 ("mm: khugepaged: better comments for anon vma check in hugepage_vma_revalidate") 4fa6893faeaa ("mm: thp: consolidate vma size check to transhuge_vma_suitable") thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 2ba99c5e08812494bc57f319fb562f527d9bacd8 Mon Sep 17 00:00:00 2001 From: Jann Horn <jannh(a)google.com> Date: Fri, 25 Nov 2022 22:37:13 +0100 Subject: [PATCH] mm/khugepaged: fix GUP-fast interaction by sending IPI Since commit 70cbc3cc78a99 ("mm: gup: fix the fast GUP race against THP collapse"), the lockless_pages_from_mm() fastpath rechecks the pmd_t to ensure that the page table was not removed by khugepaged in between. However, lockless_pages_from_mm() still requires that the page table is not concurrently freed. Fix it by sending IPIs (if the architecture uses semi-RCU-style page table freeing) before freeing/reusing page tables. Link: https://lkml.kernel.org/r/20221129154730.2274278-2-jannh@google.com Link: https://lkml.kernel.org/r/20221128180252.1684965-2-jannh@google.com Link: https://lkml.kernel.org/r/20221125213714.4115729-2-jannh@google.com Fixes: ba76149f47d8 ("thp: khugepaged") Signed-off-by: Jann Horn <jannh(a)google.com> Reviewed-by: Yang Shi <shy828301(a)gmail.com> Acked-by: David Hildenbrand <david(a)redhat.com> Cc: John Hubbard <jhubbard(a)nvidia.com> Cc: Peter Xu <peterx(a)redhat.com> Cc: <stable(a)vger.kernel.org> Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org> diff --git a/include/asm-generic/tlb.h b/include/asm-generic/tlb.h index 492dce43236e..cab7cfebf40b 100644 --- a/include/asm-generic/tlb.h +++ b/include/asm-generic/tlb.h @@ -222,12 +222,16 @@ extern void tlb_remove_table(struct mmu_gather *tlb, void *table); #define tlb_needs_table_invalidate() (true) #endif +void tlb_remove_table_sync_one(void); + #else #ifdef tlb_needs_table_invalidate #error tlb_needs_table_invalidate() requires MMU_GATHER_RCU_TABLE_FREE #endif +static inline void tlb_remove_table_sync_one(void) { } + #endif /* CONFIG_MMU_GATHER_RCU_TABLE_FREE */ diff --git a/mm/khugepaged.c b/mm/khugepaged.c index 0a11e132ad6b..294cb75d9c22 100644 --- a/mm/khugepaged.c +++ b/mm/khugepaged.c @@ -1051,6 +1051,7 @@ static int collapse_huge_page(struct mm_struct *mm, unsigned long address, _pmd = pmdp_collapse_flush(vma, address, pmd); spin_unlock(pmd_ptl); mmu_notifier_invalidate_range_end(&range); + tlb_remove_table_sync_one(); spin_lock(pte_ptl); result = __collapse_huge_page_isolate(vma, address, pte, cc, @@ -1410,6 +1411,7 @@ static void collapse_and_free_pmd(struct mm_struct *mm, struct vm_area_struct *v lockdep_assert_held_write(&vma->anon_vma->root->rwsem); pmd = pmdp_collapse_flush(vma, addr, pmdp); + tlb_remove_table_sync_one(); mm_dec_nr_ptes(mm); page_table_check_pte_clear_range(mm, addr, pmd); pte_free(mm, pmd_pgtable(pmd)); diff --git a/mm/mmu_gather.c b/mm/mmu_gather.c index add4244e5790..3a2c3f8cad2f 100644 --- a/mm/mmu_gather.c +++ b/mm/mmu_gather.c @@ -153,7 +153,7 @@ static void tlb_remove_table_smp_sync(void *arg) /* Simply deliver the interrupt */ } -static void tlb_remove_table_sync_one(void) +void tlb_remove_table_sync_one(void) { /* * This isn't an RCU grace period and hence the page-tables cannot be @@ -177,8 +177,6 @@ static void tlb_remove_table_free(struct mmu_table_batch *batch) #else /* !CONFIG_MMU_GATHER_RCU_TABLE_FREE */ -static void tlb_remove_table_sync_one(void) { } - static void tlb_remove_table_free(struct mmu_table_batch *batch) { __tlb_remove_table_free(batch);

1 year, 10 months

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FAILED: patch "[PATCH] mm/khugepaged: fix GUP-fast interaction by sending IPI" failed to apply to 5.15-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 5.15-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. Possible dependencies: 2ba99c5e0881 ("mm/khugepaged: fix GUP-fast interaction by sending IPI") 8d3c106e19e8 ("mm/khugepaged: take the right locks for page table retraction") 34488399fa08 ("mm/madvise: add file and shmem support to MADV_COLLAPSE") 58ac9a8993a1 ("mm/khugepaged: attempt to map file/shmem-backed pte-mapped THPs by pmds") 780a4b6fb865 ("mm/khugepaged: check compound_order() in collapse_pte_mapped_thp()") b26e27015ec9 ("mm: thp: convert to use common struct mm_slot") 685405020b9f ("mm/khugepaged: stop using vma linked list") 7d2c4385c341 ("mm/khugepaged: rename prefix of shared collapse functions") 7d8faaf15545 ("mm/madvise: introduce MADV_COLLAPSE sync hugepage collapse") 507228044236 ("mm/khugepaged: record SCAN_PMD_MAPPED when scan_pmd() finds hugepage") a7f4e6e4c47c ("mm/thp: add flag to enforce sysfs THP in hugepage_vma_check()") 50ad2f24b3b4 ("mm/khugepaged: propagate enum scan_result codes back to callers") 9710a78ab2ae ("mm/khugepaged: dedup and simplify hugepage alloc and charging") 34d6b470ab9c ("mm/khugepaged: add struct collapse_control") c6a7f445a272 ("mm: khugepaged: don't carry huge page to the next loop for !CONFIG_NUMA") 1064026bab9f ("mm: khugepaged: reorg some khugepaged helpers") 7da4e2cb8b1f ("mm: thp: kill __transhuge_page_enabled()") 9fec51689ff6 ("mm: thp: kill transparent_hugepage_active()") f707fa493784 ("mm: khugepaged: better comments for anon vma check in hugepage_vma_revalidate") 4fa6893faeaa ("mm: thp: consolidate vma size check to transhuge_vma_suitable") thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 2ba99c5e08812494bc57f319fb562f527d9bacd8 Mon Sep 17 00:00:00 2001 From: Jann Horn <jannh(a)google.com> Date: Fri, 25 Nov 2022 22:37:13 +0100 Subject: [PATCH] mm/khugepaged: fix GUP-fast interaction by sending IPI Since commit 70cbc3cc78a99 ("mm: gup: fix the fast GUP race against THP collapse"), the lockless_pages_from_mm() fastpath rechecks the pmd_t to ensure that the page table was not removed by khugepaged in between. However, lockless_pages_from_mm() still requires that the page table is not concurrently freed. Fix it by sending IPIs (if the architecture uses semi-RCU-style page table freeing) before freeing/reusing page tables. Link: https://lkml.kernel.org/r/20221129154730.2274278-2-jannh@google.com Link: https://lkml.kernel.org/r/20221128180252.1684965-2-jannh@google.com Link: https://lkml.kernel.org/r/20221125213714.4115729-2-jannh@google.com Fixes: ba76149f47d8 ("thp: khugepaged") Signed-off-by: Jann Horn <jannh(a)google.com> Reviewed-by: Yang Shi <shy828301(a)gmail.com> Acked-by: David Hildenbrand <david(a)redhat.com> Cc: John Hubbard <jhubbard(a)nvidia.com> Cc: Peter Xu <peterx(a)redhat.com> Cc: <stable(a)vger.kernel.org> Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org> diff --git a/include/asm-generic/tlb.h b/include/asm-generic/tlb.h index 492dce43236e..cab7cfebf40b 100644 --- a/include/asm-generic/tlb.h +++ b/include/asm-generic/tlb.h @@ -222,12 +222,16 @@ extern void tlb_remove_table(struct mmu_gather *tlb, void *table); #define tlb_needs_table_invalidate() (true) #endif +void tlb_remove_table_sync_one(void); + #else #ifdef tlb_needs_table_invalidate #error tlb_needs_table_invalidate() requires MMU_GATHER_RCU_TABLE_FREE #endif +static inline void tlb_remove_table_sync_one(void) { } + #endif /* CONFIG_MMU_GATHER_RCU_TABLE_FREE */ diff --git a/mm/khugepaged.c b/mm/khugepaged.c index 0a11e132ad6b..294cb75d9c22 100644 --- a/mm/khugepaged.c +++ b/mm/khugepaged.c @@ -1051,6 +1051,7 @@ static int collapse_huge_page(struct mm_struct *mm, unsigned long address, _pmd = pmdp_collapse_flush(vma, address, pmd); spin_unlock(pmd_ptl); mmu_notifier_invalidate_range_end(&range); + tlb_remove_table_sync_one(); spin_lock(pte_ptl); result = __collapse_huge_page_isolate(vma, address, pte, cc, @@ -1410,6 +1411,7 @@ static void collapse_and_free_pmd(struct mm_struct *mm, struct vm_area_struct *v lockdep_assert_held_write(&vma->anon_vma->root->rwsem); pmd = pmdp_collapse_flush(vma, addr, pmdp); + tlb_remove_table_sync_one(); mm_dec_nr_ptes(mm); page_table_check_pte_clear_range(mm, addr, pmd); pte_free(mm, pmd_pgtable(pmd)); diff --git a/mm/mmu_gather.c b/mm/mmu_gather.c index add4244e5790..3a2c3f8cad2f 100644 --- a/mm/mmu_gather.c +++ b/mm/mmu_gather.c @@ -153,7 +153,7 @@ static void tlb_remove_table_smp_sync(void *arg) /* Simply deliver the interrupt */ } -static void tlb_remove_table_sync_one(void) +void tlb_remove_table_sync_one(void) { /* * This isn't an RCU grace period and hence the page-tables cannot be @@ -177,8 +177,6 @@ static void tlb_remove_table_free(struct mmu_table_batch *batch) #else /* !CONFIG_MMU_GATHER_RCU_TABLE_FREE */ -static void tlb_remove_table_sync_one(void) { } - static void tlb_remove_table_free(struct mmu_table_batch *batch) { __tlb_remove_table_free(batch);

1 year, 10 months

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FAILED: patch "[PATCH] mm/khugepaged: fix GUP-fast interaction by sending IPI" failed to apply to 6.0-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 6.0-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. Possible dependencies: 2ba99c5e0881 ("mm/khugepaged: fix GUP-fast interaction by sending IPI") 8d3c106e19e8 ("mm/khugepaged: take the right locks for page table retraction") 34488399fa08 ("mm/madvise: add file and shmem support to MADV_COLLAPSE") 58ac9a8993a1 ("mm/khugepaged: attempt to map file/shmem-backed pte-mapped THPs by pmds") 780a4b6fb865 ("mm/khugepaged: check compound_order() in collapse_pte_mapped_thp()") b26e27015ec9 ("mm: thp: convert to use common struct mm_slot") 685405020b9f ("mm/khugepaged: stop using vma linked list") 7d2c4385c341 ("mm/khugepaged: rename prefix of shared collapse functions") 7d8faaf15545 ("mm/madvise: introduce MADV_COLLAPSE sync hugepage collapse") 507228044236 ("mm/khugepaged: record SCAN_PMD_MAPPED when scan_pmd() finds hugepage") a7f4e6e4c47c ("mm/thp: add flag to enforce sysfs THP in hugepage_vma_check()") 50ad2f24b3b4 ("mm/khugepaged: propagate enum scan_result codes back to callers") 9710a78ab2ae ("mm/khugepaged: dedup and simplify hugepage alloc and charging") 34d6b470ab9c ("mm/khugepaged: add struct collapse_control") c6a7f445a272 ("mm: khugepaged: don't carry huge page to the next loop for !CONFIG_NUMA") thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 2ba99c5e08812494bc57f319fb562f527d9bacd8 Mon Sep 17 00:00:00 2001 From: Jann Horn <jannh(a)google.com> Date: Fri, 25 Nov 2022 22:37:13 +0100 Subject: [PATCH] mm/khugepaged: fix GUP-fast interaction by sending IPI Since commit 70cbc3cc78a99 ("mm: gup: fix the fast GUP race against THP collapse"), the lockless_pages_from_mm() fastpath rechecks the pmd_t to ensure that the page table was not removed by khugepaged in between. However, lockless_pages_from_mm() still requires that the page table is not concurrently freed. Fix it by sending IPIs (if the architecture uses semi-RCU-style page table freeing) before freeing/reusing page tables. Link: https://lkml.kernel.org/r/20221129154730.2274278-2-jannh@google.com Link: https://lkml.kernel.org/r/20221128180252.1684965-2-jannh@google.com Link: https://lkml.kernel.org/r/20221125213714.4115729-2-jannh@google.com Fixes: ba76149f47d8 ("thp: khugepaged") Signed-off-by: Jann Horn <jannh(a)google.com> Reviewed-by: Yang Shi <shy828301(a)gmail.com> Acked-by: David Hildenbrand <david(a)redhat.com> Cc: John Hubbard <jhubbard(a)nvidia.com> Cc: Peter Xu <peterx(a)redhat.com> Cc: <stable(a)vger.kernel.org> Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org> diff --git a/include/asm-generic/tlb.h b/include/asm-generic/tlb.h index 492dce43236e..cab7cfebf40b 100644 --- a/include/asm-generic/tlb.h +++ b/include/asm-generic/tlb.h @@ -222,12 +222,16 @@ extern void tlb_remove_table(struct mmu_gather *tlb, void *table); #define tlb_needs_table_invalidate() (true) #endif +void tlb_remove_table_sync_one(void); + #else #ifdef tlb_needs_table_invalidate #error tlb_needs_table_invalidate() requires MMU_GATHER_RCU_TABLE_FREE #endif +static inline void tlb_remove_table_sync_one(void) { } + #endif /* CONFIG_MMU_GATHER_RCU_TABLE_FREE */ diff --git a/mm/khugepaged.c b/mm/khugepaged.c index 0a11e132ad6b..294cb75d9c22 100644 --- a/mm/khugepaged.c +++ b/mm/khugepaged.c @@ -1051,6 +1051,7 @@ static int collapse_huge_page(struct mm_struct *mm, unsigned long address, _pmd = pmdp_collapse_flush(vma, address, pmd); spin_unlock(pmd_ptl); mmu_notifier_invalidate_range_end(&range); + tlb_remove_table_sync_one(); spin_lock(pte_ptl); result = __collapse_huge_page_isolate(vma, address, pte, cc, @@ -1410,6 +1411,7 @@ static void collapse_and_free_pmd(struct mm_struct *mm, struct vm_area_struct *v lockdep_assert_held_write(&vma->anon_vma->root->rwsem); pmd = pmdp_collapse_flush(vma, addr, pmdp); + tlb_remove_table_sync_one(); mm_dec_nr_ptes(mm); page_table_check_pte_clear_range(mm, addr, pmd); pte_free(mm, pmd_pgtable(pmd)); diff --git a/mm/mmu_gather.c b/mm/mmu_gather.c index add4244e5790..3a2c3f8cad2f 100644 --- a/mm/mmu_gather.c +++ b/mm/mmu_gather.c @@ -153,7 +153,7 @@ static void tlb_remove_table_smp_sync(void *arg) /* Simply deliver the interrupt */ } -static void tlb_remove_table_sync_one(void) +void tlb_remove_table_sync_one(void) { /* * This isn't an RCU grace period and hence the page-tables cannot be @@ -177,8 +177,6 @@ static void tlb_remove_table_free(struct mmu_table_batch *batch) #else /* !CONFIG_MMU_GATHER_RCU_TABLE_FREE */ -static void tlb_remove_table_sync_one(void) { } - static void tlb_remove_table_free(struct mmu_table_batch *batch) { __tlb_remove_table_free(batch);

1 year, 10 months

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FAILED: patch "[PATCH] mm/khugepaged: take the right locks for page table retraction" failed to apply to 5.4-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 5.4-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. Possible dependencies: 8d3c106e19e8 ("mm/khugepaged: take the right locks for page table retraction") 34488399fa08 ("mm/madvise: add file and shmem support to MADV_COLLAPSE") 58ac9a8993a1 ("mm/khugepaged: attempt to map file/shmem-backed pte-mapped THPs by pmds") 780a4b6fb865 ("mm/khugepaged: check compound_order() in collapse_pte_mapped_thp()") b26e27015ec9 ("mm: thp: convert to use common struct mm_slot") 685405020b9f ("mm/khugepaged: stop using vma linked list") 7d2c4385c341 ("mm/khugepaged: rename prefix of shared collapse functions") 7d8faaf15545 ("mm/madvise: introduce MADV_COLLAPSE sync hugepage collapse") 507228044236 ("mm/khugepaged: record SCAN_PMD_MAPPED when scan_pmd() finds hugepage") a7f4e6e4c47c ("mm/thp: add flag to enforce sysfs THP in hugepage_vma_check()") 50ad2f24b3b4 ("mm/khugepaged: propagate enum scan_result codes back to callers") 9710a78ab2ae ("mm/khugepaged: dedup and simplify hugepage alloc and charging") 34d6b470ab9c ("mm/khugepaged: add struct collapse_control") c6a7f445a272 ("mm: khugepaged: don't carry huge page to the next loop for !CONFIG_NUMA") 1064026bab9f ("mm: khugepaged: reorg some khugepaged helpers") 7da4e2cb8b1f ("mm: thp: kill __transhuge_page_enabled()") 9fec51689ff6 ("mm: thp: kill transparent_hugepage_active()") f707fa493784 ("mm: khugepaged: better comments for anon vma check in hugepage_vma_revalidate") 4fa6893faeaa ("mm: thp: consolidate vma size check to transhuge_vma_suitable") 66137fb34a4b ("mm: khugepaged: check THP flag in hugepage_vma_check()") thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 8d3c106e19e8d251da31ff4cc7462e4565d65084 Mon Sep 17 00:00:00 2001 From: Jann Horn <jannh(a)google.com> Date: Fri, 25 Nov 2022 22:37:12 +0100 Subject: [PATCH] mm/khugepaged: take the right locks for page table retraction pagetable walks on address ranges mapped by VMAs can be done under the mmap lock, the lock of an anon_vma attached to the VMA, or the lock of the VMA's address_space. Only one of these needs to be held, and it does not need to be held in exclusive mode. Under those circumstances, the rules for concurrent access to page table entries are: - Terminal page table entries (entries that don't point to another page table) can be arbitrarily changed under the page table lock, with the exception that they always need to be consistent for hardware page table walks and lockless_pages_from_mm(). This includes that they can be changed into non-terminal entries. - Non-terminal page table entries (which point to another page table) can not be modified; readers are allowed to READ_ONCE() an entry, verify that it is non-terminal, and then assume that its value will stay as-is. Retracting a page table involves modifying a non-terminal entry, so page-table-level locks are insufficient to protect against concurrent page table traversal; it requires taking all the higher-level locks under which it is possible to start a page walk in the relevant range in exclusive mode. The collapse_huge_page() path for anonymous THP already follows this rule, but the shmem/file THP path was getting it wrong, making it possible for concurrent rmap-based operations to cause corruption. Link: https://lkml.kernel.org/r/20221129154730.2274278-1-jannh@google.com Link: https://lkml.kernel.org/r/20221128180252.1684965-1-jannh@google.com Link: https://lkml.kernel.org/r/20221125213714.4115729-1-jannh@google.com Fixes: 27e1f8273113 ("khugepaged: enable collapse pmd for pte-mapped THP") Signed-off-by: Jann Horn <jannh(a)google.com> Reviewed-by: Yang Shi <shy828301(a)gmail.com> Acked-by: David Hildenbrand <david(a)redhat.com> Cc: John Hubbard <jhubbard(a)nvidia.com> Cc: Peter Xu <peterx(a)redhat.com> Cc: <stable(a)vger.kernel.org> Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org> diff --git a/mm/khugepaged.c b/mm/khugepaged.c index a8d5ef2a77d2..0a11e132ad6b 100644 --- a/mm/khugepaged.c +++ b/mm/khugepaged.c @@ -1379,16 +1379,37 @@ static int set_huge_pmd(struct vm_area_struct *vma, unsigned long addr, return SCAN_SUCCEED; } +/* + * A note about locking: + * Trying to take the page table spinlocks would be useless here because those + * are only used to synchronize: + * + * - modifying terminal entries (ones that point to a data page, not to another + * page table) + * - installing *new* non-terminal entries + * + * Instead, we need roughly the same kind of protection as free_pgtables() or + * mm_take_all_locks() (but only for a single VMA): + * The mmap lock together with this VMA's rmap locks covers all paths towards + * the page table entries we're messing with here, except for hardware page + * table walks and lockless_pages_from_mm(). + */ static void collapse_and_free_pmd(struct mm_struct *mm, struct vm_area_struct *vma, unsigned long addr, pmd_t *pmdp) { - spinlock_t *ptl; pmd_t pmd; mmap_assert_write_locked(mm); - ptl = pmd_lock(vma->vm_mm, pmdp); + if (vma->vm_file) + lockdep_assert_held_write(&vma->vm_file->f_mapping->i_mmap_rwsem); + /* + * All anon_vmas attached to the VMA have the same root and are + * therefore locked by the same lock. + */ + if (vma->anon_vma) + lockdep_assert_held_write(&vma->anon_vma->root->rwsem); + pmd = pmdp_collapse_flush(vma, addr, pmdp); - spin_unlock(ptl); mm_dec_nr_ptes(mm); page_table_check_pte_clear_range(mm, addr, pmd); pte_free(mm, pmd_pgtable(pmd)); @@ -1439,6 +1460,14 @@ int collapse_pte_mapped_thp(struct mm_struct *mm, unsigned long addr, if (!hugepage_vma_check(vma, vma->vm_flags, false, false, false)) return SCAN_VMA_CHECK; + /* + * Symmetry with retract_page_tables(): Exclude MAP_PRIVATE mappings + * that got written to. Without this, we'd have to also lock the + * anon_vma if one exists. + */ + if (vma->anon_vma) + return SCAN_VMA_CHECK; + /* Keep pmd pgtable for uffd-wp; see comment in retract_page_tables() */ if (userfaultfd_wp(vma)) return SCAN_PTE_UFFD_WP; @@ -1472,6 +1501,20 @@ int collapse_pte_mapped_thp(struct mm_struct *mm, unsigned long addr, goto drop_hpage; } + /* + * We need to lock the mapping so that from here on, only GUP-fast and + * hardware page walks can access the parts of the page tables that + * we're operating on. + * See collapse_and_free_pmd(). + */ + i_mmap_lock_write(vma->vm_file->f_mapping); + + /* + * This spinlock should be unnecessary: Nobody else should be accessing + * the page tables under spinlock protection here, only + * lockless_pages_from_mm() and the hardware page walker can access page + * tables while all the high-level locks are held in write mode. + */ start_pte = pte_offset_map_lock(mm, pmd, haddr, &ptl); result = SCAN_FAIL; @@ -1526,6 +1569,8 @@ int collapse_pte_mapped_thp(struct mm_struct *mm, unsigned long addr, /* step 4: remove pte entries */ collapse_and_free_pmd(mm, vma, haddr, pmd); + i_mmap_unlock_write(vma->vm_file->f_mapping); + maybe_install_pmd: /* step 5: install pmd entry */ result = install_pmd @@ -1539,6 +1584,7 @@ int collapse_pte_mapped_thp(struct mm_struct *mm, unsigned long addr, abort: pte_unmap_unlock(start_pte, ptl); + i_mmap_unlock_write(vma->vm_file->f_mapping); goto drop_hpage; } @@ -1595,7 +1641,8 @@ static int retract_page_tables(struct address_space *mapping, pgoff_t pgoff, * An alternative would be drop the check, but check that page * table is clear before calling pmdp_collapse_flush() under * ptl. It has higher chance to recover THP for the VMA, but - * has higher cost too. + * has higher cost too. It would also probably require locking + * the anon_vma. */ if (vma->anon_vma) { result = SCAN_PAGE_ANON;

1 year, 10 months

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FAILED: patch "[PATCH] mm/khugepaged: take the right locks for page table retraction" failed to apply to 5.10-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 5.10-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. Possible dependencies: 8d3c106e19e8 ("mm/khugepaged: take the right locks for page table retraction") 34488399fa08 ("mm/madvise: add file and shmem support to MADV_COLLAPSE") 58ac9a8993a1 ("mm/khugepaged: attempt to map file/shmem-backed pte-mapped THPs by pmds") 780a4b6fb865 ("mm/khugepaged: check compound_order() in collapse_pte_mapped_thp()") b26e27015ec9 ("mm: thp: convert to use common struct mm_slot") 685405020b9f ("mm/khugepaged: stop using vma linked list") 7d2c4385c341 ("mm/khugepaged: rename prefix of shared collapse functions") 7d8faaf15545 ("mm/madvise: introduce MADV_COLLAPSE sync hugepage collapse") 507228044236 ("mm/khugepaged: record SCAN_PMD_MAPPED when scan_pmd() finds hugepage") a7f4e6e4c47c ("mm/thp: add flag to enforce sysfs THP in hugepage_vma_check()") 50ad2f24b3b4 ("mm/khugepaged: propagate enum scan_result codes back to callers") 9710a78ab2ae ("mm/khugepaged: dedup and simplify hugepage alloc and charging") 34d6b470ab9c ("mm/khugepaged: add struct collapse_control") c6a7f445a272 ("mm: khugepaged: don't carry huge page to the next loop for !CONFIG_NUMA") 1064026bab9f ("mm: khugepaged: reorg some khugepaged helpers") 7da4e2cb8b1f ("mm: thp: kill __transhuge_page_enabled()") 9fec51689ff6 ("mm: thp: kill transparent_hugepage_active()") f707fa493784 ("mm: khugepaged: better comments for anon vma check in hugepage_vma_revalidate") 4fa6893faeaa ("mm: thp: consolidate vma size check to transhuge_vma_suitable") 66137fb34a4b ("mm: khugepaged: check THP flag in hugepage_vma_check()") thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 8d3c106e19e8d251da31ff4cc7462e4565d65084 Mon Sep 17 00:00:00 2001 From: Jann Horn <jannh(a)google.com> Date: Fri, 25 Nov 2022 22:37:12 +0100 Subject: [PATCH] mm/khugepaged: take the right locks for page table retraction pagetable walks on address ranges mapped by VMAs can be done under the mmap lock, the lock of an anon_vma attached to the VMA, or the lock of the VMA's address_space. Only one of these needs to be held, and it does not need to be held in exclusive mode. Under those circumstances, the rules for concurrent access to page table entries are: - Terminal page table entries (entries that don't point to another page table) can be arbitrarily changed under the page table lock, with the exception that they always need to be consistent for hardware page table walks and lockless_pages_from_mm(). This includes that they can be changed into non-terminal entries. - Non-terminal page table entries (which point to another page table) can not be modified; readers are allowed to READ_ONCE() an entry, verify that it is non-terminal, and then assume that its value will stay as-is. Retracting a page table involves modifying a non-terminal entry, so page-table-level locks are insufficient to protect against concurrent page table traversal; it requires taking all the higher-level locks under which it is possible to start a page walk in the relevant range in exclusive mode. The collapse_huge_page() path for anonymous THP already follows this rule, but the shmem/file THP path was getting it wrong, making it possible for concurrent rmap-based operations to cause corruption. Link: https://lkml.kernel.org/r/20221129154730.2274278-1-jannh@google.com Link: https://lkml.kernel.org/r/20221128180252.1684965-1-jannh@google.com Link: https://lkml.kernel.org/r/20221125213714.4115729-1-jannh@google.com Fixes: 27e1f8273113 ("khugepaged: enable collapse pmd for pte-mapped THP") Signed-off-by: Jann Horn <jannh(a)google.com> Reviewed-by: Yang Shi <shy828301(a)gmail.com> Acked-by: David Hildenbrand <david(a)redhat.com> Cc: John Hubbard <jhubbard(a)nvidia.com> Cc: Peter Xu <peterx(a)redhat.com> Cc: <stable(a)vger.kernel.org> Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org> diff --git a/mm/khugepaged.c b/mm/khugepaged.c index a8d5ef2a77d2..0a11e132ad6b 100644 --- a/mm/khugepaged.c +++ b/mm/khugepaged.c @@ -1379,16 +1379,37 @@ static int set_huge_pmd(struct vm_area_struct *vma, unsigned long addr, return SCAN_SUCCEED; } +/* + * A note about locking: + * Trying to take the page table spinlocks would be useless here because those + * are only used to synchronize: + * + * - modifying terminal entries (ones that point to a data page, not to another + * page table) + * - installing *new* non-terminal entries + * + * Instead, we need roughly the same kind of protection as free_pgtables() or + * mm_take_all_locks() (but only for a single VMA): + * The mmap lock together with this VMA's rmap locks covers all paths towards + * the page table entries we're messing with here, except for hardware page + * table walks and lockless_pages_from_mm(). + */ static void collapse_and_free_pmd(struct mm_struct *mm, struct vm_area_struct *vma, unsigned long addr, pmd_t *pmdp) { - spinlock_t *ptl; pmd_t pmd; mmap_assert_write_locked(mm); - ptl = pmd_lock(vma->vm_mm, pmdp); + if (vma->vm_file) + lockdep_assert_held_write(&vma->vm_file->f_mapping->i_mmap_rwsem); + /* + * All anon_vmas attached to the VMA have the same root and are + * therefore locked by the same lock. + */ + if (vma->anon_vma) + lockdep_assert_held_write(&vma->anon_vma->root->rwsem); + pmd = pmdp_collapse_flush(vma, addr, pmdp); - spin_unlock(ptl); mm_dec_nr_ptes(mm); page_table_check_pte_clear_range(mm, addr, pmd); pte_free(mm, pmd_pgtable(pmd)); @@ -1439,6 +1460,14 @@ int collapse_pte_mapped_thp(struct mm_struct *mm, unsigned long addr, if (!hugepage_vma_check(vma, vma->vm_flags, false, false, false)) return SCAN_VMA_CHECK; + /* + * Symmetry with retract_page_tables(): Exclude MAP_PRIVATE mappings + * that got written to. Without this, we'd have to also lock the + * anon_vma if one exists. + */ + if (vma->anon_vma) + return SCAN_VMA_CHECK; + /* Keep pmd pgtable for uffd-wp; see comment in retract_page_tables() */ if (userfaultfd_wp(vma)) return SCAN_PTE_UFFD_WP; @@ -1472,6 +1501,20 @@ int collapse_pte_mapped_thp(struct mm_struct *mm, unsigned long addr, goto drop_hpage; } + /* + * We need to lock the mapping so that from here on, only GUP-fast and + * hardware page walks can access the parts of the page tables that + * we're operating on. + * See collapse_and_free_pmd(). + */ + i_mmap_lock_write(vma->vm_file->f_mapping); + + /* + * This spinlock should be unnecessary: Nobody else should be accessing + * the page tables under spinlock protection here, only + * lockless_pages_from_mm() and the hardware page walker can access page + * tables while all the high-level locks are held in write mode. + */ start_pte = pte_offset_map_lock(mm, pmd, haddr, &ptl); result = SCAN_FAIL; @@ -1526,6 +1569,8 @@ int collapse_pte_mapped_thp(struct mm_struct *mm, unsigned long addr, /* step 4: remove pte entries */ collapse_and_free_pmd(mm, vma, haddr, pmd); + i_mmap_unlock_write(vma->vm_file->f_mapping); + maybe_install_pmd: /* step 5: install pmd entry */ result = install_pmd @@ -1539,6 +1584,7 @@ int collapse_pte_mapped_thp(struct mm_struct *mm, unsigned long addr, abort: pte_unmap_unlock(start_pte, ptl); + i_mmap_unlock_write(vma->vm_file->f_mapping); goto drop_hpage; } @@ -1595,7 +1641,8 @@ static int retract_page_tables(struct address_space *mapping, pgoff_t pgoff, * An alternative would be drop the check, but check that page * table is clear before calling pmdp_collapse_flush() under * ptl. It has higher chance to recover THP for the VMA, but - * has higher cost too. + * has higher cost too. It would also probably require locking + * the anon_vma. */ if (vma->anon_vma) { result = SCAN_PAGE_ANON;

1 year, 10 months

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FAILED: patch "[PATCH] mm/khugepaged: take the right locks for page table retraction" failed to apply to 5.15-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 5.15-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. Possible dependencies: 8d3c106e19e8 ("mm/khugepaged: take the right locks for page table retraction") 34488399fa08 ("mm/madvise: add file and shmem support to MADV_COLLAPSE") 58ac9a8993a1 ("mm/khugepaged: attempt to map file/shmem-backed pte-mapped THPs by pmds") 780a4b6fb865 ("mm/khugepaged: check compound_order() in collapse_pte_mapped_thp()") b26e27015ec9 ("mm: thp: convert to use common struct mm_slot") 685405020b9f ("mm/khugepaged: stop using vma linked list") 7d2c4385c341 ("mm/khugepaged: rename prefix of shared collapse functions") 7d8faaf15545 ("mm/madvise: introduce MADV_COLLAPSE sync hugepage collapse") 507228044236 ("mm/khugepaged: record SCAN_PMD_MAPPED when scan_pmd() finds hugepage") a7f4e6e4c47c ("mm/thp: add flag to enforce sysfs THP in hugepage_vma_check()") 50ad2f24b3b4 ("mm/khugepaged: propagate enum scan_result codes back to callers") 9710a78ab2ae ("mm/khugepaged: dedup and simplify hugepage alloc and charging") 34d6b470ab9c ("mm/khugepaged: add struct collapse_control") c6a7f445a272 ("mm: khugepaged: don't carry huge page to the next loop for !CONFIG_NUMA") 1064026bab9f ("mm: khugepaged: reorg some khugepaged helpers") 7da4e2cb8b1f ("mm: thp: kill __transhuge_page_enabled()") 9fec51689ff6 ("mm: thp: kill transparent_hugepage_active()") f707fa493784 ("mm: khugepaged: better comments for anon vma check in hugepage_vma_revalidate") 4fa6893faeaa ("mm: thp: consolidate vma size check to transhuge_vma_suitable") 66137fb34a4b ("mm: khugepaged: check THP flag in hugepage_vma_check()") thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 8d3c106e19e8d251da31ff4cc7462e4565d65084 Mon Sep 17 00:00:00 2001 From: Jann Horn <jannh(a)google.com> Date: Fri, 25 Nov 2022 22:37:12 +0100 Subject: [PATCH] mm/khugepaged: take the right locks for page table retraction pagetable walks on address ranges mapped by VMAs can be done under the mmap lock, the lock of an anon_vma attached to the VMA, or the lock of the VMA's address_space. Only one of these needs to be held, and it does not need to be held in exclusive mode. Under those circumstances, the rules for concurrent access to page table entries are: - Terminal page table entries (entries that don't point to another page table) can be arbitrarily changed under the page table lock, with the exception that they always need to be consistent for hardware page table walks and lockless_pages_from_mm(). This includes that they can be changed into non-terminal entries. - Non-terminal page table entries (which point to another page table) can not be modified; readers are allowed to READ_ONCE() an entry, verify that it is non-terminal, and then assume that its value will stay as-is. Retracting a page table involves modifying a non-terminal entry, so page-table-level locks are insufficient to protect against concurrent page table traversal; it requires taking all the higher-level locks under which it is possible to start a page walk in the relevant range in exclusive mode. The collapse_huge_page() path for anonymous THP already follows this rule, but the shmem/file THP path was getting it wrong, making it possible for concurrent rmap-based operations to cause corruption. Link: https://lkml.kernel.org/r/20221129154730.2274278-1-jannh@google.com Link: https://lkml.kernel.org/r/20221128180252.1684965-1-jannh@google.com Link: https://lkml.kernel.org/r/20221125213714.4115729-1-jannh@google.com Fixes: 27e1f8273113 ("khugepaged: enable collapse pmd for pte-mapped THP") Signed-off-by: Jann Horn <jannh(a)google.com> Reviewed-by: Yang Shi <shy828301(a)gmail.com> Acked-by: David Hildenbrand <david(a)redhat.com> Cc: John Hubbard <jhubbard(a)nvidia.com> Cc: Peter Xu <peterx(a)redhat.com> Cc: <stable(a)vger.kernel.org> Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org> diff --git a/mm/khugepaged.c b/mm/khugepaged.c index a8d5ef2a77d2..0a11e132ad6b 100644 --- a/mm/khugepaged.c +++ b/mm/khugepaged.c @@ -1379,16 +1379,37 @@ static int set_huge_pmd(struct vm_area_struct *vma, unsigned long addr, return SCAN_SUCCEED; } +/* + * A note about locking: + * Trying to take the page table spinlocks would be useless here because those + * are only used to synchronize: + * + * - modifying terminal entries (ones that point to a data page, not to another + * page table) + * - installing *new* non-terminal entries + * + * Instead, we need roughly the same kind of protection as free_pgtables() or + * mm_take_all_locks() (but only for a single VMA): + * The mmap lock together with this VMA's rmap locks covers all paths towards + * the page table entries we're messing with here, except for hardware page + * table walks and lockless_pages_from_mm(). + */ static void collapse_and_free_pmd(struct mm_struct *mm, struct vm_area_struct *vma, unsigned long addr, pmd_t *pmdp) { - spinlock_t *ptl; pmd_t pmd; mmap_assert_write_locked(mm); - ptl = pmd_lock(vma->vm_mm, pmdp); + if (vma->vm_file) + lockdep_assert_held_write(&vma->vm_file->f_mapping->i_mmap_rwsem); + /* + * All anon_vmas attached to the VMA have the same root and are + * therefore locked by the same lock. + */ + if (vma->anon_vma) + lockdep_assert_held_write(&vma->anon_vma->root->rwsem); + pmd = pmdp_collapse_flush(vma, addr, pmdp); - spin_unlock(ptl); mm_dec_nr_ptes(mm); page_table_check_pte_clear_range(mm, addr, pmd); pte_free(mm, pmd_pgtable(pmd)); @@ -1439,6 +1460,14 @@ int collapse_pte_mapped_thp(struct mm_struct *mm, unsigned long addr, if (!hugepage_vma_check(vma, vma->vm_flags, false, false, false)) return SCAN_VMA_CHECK; + /* + * Symmetry with retract_page_tables(): Exclude MAP_PRIVATE mappings + * that got written to. Without this, we'd have to also lock the + * anon_vma if one exists. + */ + if (vma->anon_vma) + return SCAN_VMA_CHECK; + /* Keep pmd pgtable for uffd-wp; see comment in retract_page_tables() */ if (userfaultfd_wp(vma)) return SCAN_PTE_UFFD_WP; @@ -1472,6 +1501,20 @@ int collapse_pte_mapped_thp(struct mm_struct *mm, unsigned long addr, goto drop_hpage; } + /* + * We need to lock the mapping so that from here on, only GUP-fast and + * hardware page walks can access the parts of the page tables that + * we're operating on. + * See collapse_and_free_pmd(). + */ + i_mmap_lock_write(vma->vm_file->f_mapping); + + /* + * This spinlock should be unnecessary: Nobody else should be accessing + * the page tables under spinlock protection here, only + * lockless_pages_from_mm() and the hardware page walker can access page + * tables while all the high-level locks are held in write mode. + */ start_pte = pte_offset_map_lock(mm, pmd, haddr, &ptl); result = SCAN_FAIL; @@ -1526,6 +1569,8 @@ int collapse_pte_mapped_thp(struct mm_struct *mm, unsigned long addr, /* step 4: remove pte entries */ collapse_and_free_pmd(mm, vma, haddr, pmd); + i_mmap_unlock_write(vma->vm_file->f_mapping); + maybe_install_pmd: /* step 5: install pmd entry */ result = install_pmd @@ -1539,6 +1584,7 @@ int collapse_pte_mapped_thp(struct mm_struct *mm, unsigned long addr, abort: pte_unmap_unlock(start_pte, ptl); + i_mmap_unlock_write(vma->vm_file->f_mapping); goto drop_hpage; } @@ -1595,7 +1641,8 @@ static int retract_page_tables(struct address_space *mapping, pgoff_t pgoff, * An alternative would be drop the check, but check that page * table is clear before calling pmdp_collapse_flush() under * ptl. It has higher chance to recover THP for the VMA, but - * has higher cost too. + * has higher cost too. It would also probably require locking + * the anon_vma. */ if (vma->anon_vma) { result = SCAN_PAGE_ANON;

1 year, 10 months

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FAILED: patch "[PATCH] mm/khugepaged: take the right locks for page table retraction" failed to apply to 6.0-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 6.0-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. Possible dependencies: 8d3c106e19e8 ("mm/khugepaged: take the right locks for page table retraction") 34488399fa08 ("mm/madvise: add file and shmem support to MADV_COLLAPSE") 58ac9a8993a1 ("mm/khugepaged: attempt to map file/shmem-backed pte-mapped THPs by pmds") 780a4b6fb865 ("mm/khugepaged: check compound_order() in collapse_pte_mapped_thp()") b26e27015ec9 ("mm: thp: convert to use common struct mm_slot") 685405020b9f ("mm/khugepaged: stop using vma linked list") 7d2c4385c341 ("mm/khugepaged: rename prefix of shared collapse functions") 7d8faaf15545 ("mm/madvise: introduce MADV_COLLAPSE sync hugepage collapse") 507228044236 ("mm/khugepaged: record SCAN_PMD_MAPPED when scan_pmd() finds hugepage") a7f4e6e4c47c ("mm/thp: add flag to enforce sysfs THP in hugepage_vma_check()") 50ad2f24b3b4 ("mm/khugepaged: propagate enum scan_result codes back to callers") 9710a78ab2ae ("mm/khugepaged: dedup and simplify hugepage alloc and charging") 34d6b470ab9c ("mm/khugepaged: add struct collapse_control") c6a7f445a272 ("mm: khugepaged: don't carry huge page to the next loop for !CONFIG_NUMA") thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 8d3c106e19e8d251da31ff4cc7462e4565d65084 Mon Sep 17 00:00:00 2001 From: Jann Horn <jannh(a)google.com> Date: Fri, 25 Nov 2022 22:37:12 +0100 Subject: [PATCH] mm/khugepaged: take the right locks for page table retraction pagetable walks on address ranges mapped by VMAs can be done under the mmap lock, the lock of an anon_vma attached to the VMA, or the lock of the VMA's address_space. Only one of these needs to be held, and it does not need to be held in exclusive mode. Under those circumstances, the rules for concurrent access to page table entries are: - Terminal page table entries (entries that don't point to another page table) can be arbitrarily changed under the page table lock, with the exception that they always need to be consistent for hardware page table walks and lockless_pages_from_mm(). This includes that they can be changed into non-terminal entries. - Non-terminal page table entries (which point to another page table) can not be modified; readers are allowed to READ_ONCE() an entry, verify that it is non-terminal, and then assume that its value will stay as-is. Retracting a page table involves modifying a non-terminal entry, so page-table-level locks are insufficient to protect against concurrent page table traversal; it requires taking all the higher-level locks under which it is possible to start a page walk in the relevant range in exclusive mode. The collapse_huge_page() path for anonymous THP already follows this rule, but the shmem/file THP path was getting it wrong, making it possible for concurrent rmap-based operations to cause corruption. Link: https://lkml.kernel.org/r/20221129154730.2274278-1-jannh@google.com Link: https://lkml.kernel.org/r/20221128180252.1684965-1-jannh@google.com Link: https://lkml.kernel.org/r/20221125213714.4115729-1-jannh@google.com Fixes: 27e1f8273113 ("khugepaged: enable collapse pmd for pte-mapped THP") Signed-off-by: Jann Horn <jannh(a)google.com> Reviewed-by: Yang Shi <shy828301(a)gmail.com> Acked-by: David Hildenbrand <david(a)redhat.com> Cc: John Hubbard <jhubbard(a)nvidia.com> Cc: Peter Xu <peterx(a)redhat.com> Cc: <stable(a)vger.kernel.org> Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org> diff --git a/mm/khugepaged.c b/mm/khugepaged.c index a8d5ef2a77d2..0a11e132ad6b 100644 --- a/mm/khugepaged.c +++ b/mm/khugepaged.c @@ -1379,16 +1379,37 @@ static int set_huge_pmd(struct vm_area_struct *vma, unsigned long addr, return SCAN_SUCCEED; } +/* + * A note about locking: + * Trying to take the page table spinlocks would be useless here because those + * are only used to synchronize: + * + * - modifying terminal entries (ones that point to a data page, not to another + * page table) + * - installing *new* non-terminal entries + * + * Instead, we need roughly the same kind of protection as free_pgtables() or + * mm_take_all_locks() (but only for a single VMA): + * The mmap lock together with this VMA's rmap locks covers all paths towards + * the page table entries we're messing with here, except for hardware page + * table walks and lockless_pages_from_mm(). + */ static void collapse_and_free_pmd(struct mm_struct *mm, struct vm_area_struct *vma, unsigned long addr, pmd_t *pmdp) { - spinlock_t *ptl; pmd_t pmd; mmap_assert_write_locked(mm); - ptl = pmd_lock(vma->vm_mm, pmdp); + if (vma->vm_file) + lockdep_assert_held_write(&vma->vm_file->f_mapping->i_mmap_rwsem); + /* + * All anon_vmas attached to the VMA have the same root and are + * therefore locked by the same lock. + */ + if (vma->anon_vma) + lockdep_assert_held_write(&vma->anon_vma->root->rwsem); + pmd = pmdp_collapse_flush(vma, addr, pmdp); - spin_unlock(ptl); mm_dec_nr_ptes(mm); page_table_check_pte_clear_range(mm, addr, pmd); pte_free(mm, pmd_pgtable(pmd)); @@ -1439,6 +1460,14 @@ int collapse_pte_mapped_thp(struct mm_struct *mm, unsigned long addr, if (!hugepage_vma_check(vma, vma->vm_flags, false, false, false)) return SCAN_VMA_CHECK; + /* + * Symmetry with retract_page_tables(): Exclude MAP_PRIVATE mappings + * that got written to. Without this, we'd have to also lock the + * anon_vma if one exists. + */ + if (vma->anon_vma) + return SCAN_VMA_CHECK; + /* Keep pmd pgtable for uffd-wp; see comment in retract_page_tables() */ if (userfaultfd_wp(vma)) return SCAN_PTE_UFFD_WP; @@ -1472,6 +1501,20 @@ int collapse_pte_mapped_thp(struct mm_struct *mm, unsigned long addr, goto drop_hpage; } + /* + * We need to lock the mapping so that from here on, only GUP-fast and + * hardware page walks can access the parts of the page tables that + * we're operating on. + * See collapse_and_free_pmd(). + */ + i_mmap_lock_write(vma->vm_file->f_mapping); + + /* + * This spinlock should be unnecessary: Nobody else should be accessing + * the page tables under spinlock protection here, only + * lockless_pages_from_mm() and the hardware page walker can access page + * tables while all the high-level locks are held in write mode. + */ start_pte = pte_offset_map_lock(mm, pmd, haddr, &ptl); result = SCAN_FAIL; @@ -1526,6 +1569,8 @@ int collapse_pte_mapped_thp(struct mm_struct *mm, unsigned long addr, /* step 4: remove pte entries */ collapse_and_free_pmd(mm, vma, haddr, pmd); + i_mmap_unlock_write(vma->vm_file->f_mapping); + maybe_install_pmd: /* step 5: install pmd entry */ result = install_pmd @@ -1539,6 +1584,7 @@ int collapse_pte_mapped_thp(struct mm_struct *mm, unsigned long addr, abort: pte_unmap_unlock(start_pte, ptl); + i_mmap_unlock_write(vma->vm_file->f_mapping); goto drop_hpage; } @@ -1595,7 +1641,8 @@ static int retract_page_tables(struct address_space *mapping, pgoff_t pgoff, * An alternative would be drop the check, but check that page * table is clear before calling pmdp_collapse_flush() under * ptl. It has higher chance to recover THP for the VMA, but - * has higher cost too. + * has higher cost too. It would also probably require locking + * the anon_vma. */ if (vma->anon_vma) { result = SCAN_PAGE_ANON;

1 year, 10 months

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FAILED: patch "[PATCH] tracing: Free buffers when a used dynamic event is removed" failed to apply to 4.9-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 4.9-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. Possible dependencies: 4313e5a61304 ("tracing: Free buffers when a used dynamic event is removed") 5448d44c3855 ("tracing: Add unified dynamic event framework") 6b0b7551428e ("perf/core: Rename CONFIG_[UK]PROBE_EVENT to CONFIG_[UK]PROBE_EVENTS") 1d9995771fcb ("s390: update defconfigs") thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 4313e5a613049dfc1819a6dfb5f94cf2caff9452 Mon Sep 17 00:00:00 2001 From: "Steven Rostedt (Google)" <rostedt(a)goodmis.org> Date: Wed, 23 Nov 2022 17:14:34 -0500 Subject: [PATCH] tracing: Free buffers when a used dynamic event is removed MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit After 65536 dynamic events have been added and removed, the "type" field of the event then uses the first type number that is available (not currently used by other events). A type number is the identifier of the binary blobs in the tracing ring buffer (known as events) to map them to logic that can parse the binary blob. The issue is that if a dynamic event (like a kprobe event) is traced and is in the ring buffer, and then that event is removed (because it is dynamic, which means it can be created and destroyed), if another dynamic event is created that has the same number that new event's logic on parsing the binary blob will be used. To show how this can be an issue, the following can crash the kernel: # cd /sys/kernel/tracing # for i in `seq 65536`; do echo 'p:kprobes/foo do_sys_openat2 $arg1:u32' > kprobe_events # done For every iteration of the above, the writing to the kprobe_events will remove the old event and create a new one (with the same format) and increase the type number to the next available on until the type number reaches over 65535 which is the max number for the 16 bit type. After it reaches that number, the logic to allocate a new number simply looks for the next available number. When an dynamic event is removed, that number is then available to be reused by the next dynamic event created. That is, once the above reaches the max number, the number assigned to the event in that loop will remain the same. Now that means deleting one dynamic event and created another will reuse the previous events type number. This is where bad things can happen. After the above loop finishes, the kprobes/foo event which reads the do_sys_openat2 function call's first parameter as an integer. # echo 1 > kprobes/foo/enable # cat /etc/passwd > /dev/null # cat trace cat-2211 [005] .... 2007.849603: foo: (do_sys_openat2+0x0/0x130) arg1=4294967196 cat-2211 [005] .... 2007.849620: foo: (do_sys_openat2+0x0/0x130) arg1=4294967196 cat-2211 [005] .... 2007.849838: foo: (do_sys_openat2+0x0/0x130) arg1=4294967196 cat-2211 [005] .... 2007.849880: foo: (do_sys_openat2+0x0/0x130) arg1=4294967196 # echo 0 > kprobes/foo/enable Now if we delete the kprobe and create a new one that reads a string: # echo 'p:kprobes/foo do_sys_openat2 +0($arg2):string' > kprobe_events And now we can the trace: # cat trace sendmail-1942 [002] ..... 530.136320: foo: (do_sys_openat2+0x0/0x240) arg1= cat-2046 [004] ..... 530.930817: foo: (do_sys_openat2+0x0/0x240) arg1="��" cat-2046 [004] ..... 530.930961: foo: (do_sys_openat2+0x0/0x240) arg1="��" cat-2046 [004] ..... 530.934278: foo: (do_sys_openat2+0x0/0x240) arg1="��" cat-2046 [004] ..... 530.934563: foo: (do_sys_openat2+0x0/0x240) arg1="��" bash-1515 [007] ..... 534.299093: foo: (do_sys_openat2+0x0/0x240) arg1="kkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkk��@��4Z��;Y��U And dmesg has: ================================================================== BUG: KASAN: use-after-free in string+0xd4/0x1c0 Read of size 1 at addr ffff88805fdbbfa0 by task cat/2049 CPU: 0 PID: 2049 Comm: cat Not tainted 6.1.0-rc6-test+ #641 Hardware name: Hewlett-Packard HP Compaq Pro 6300 SFF/339A, BIOS K01 v03.03 07/14/2016 Call Trace: <TASK> dump_stack_lvl+0x5b/0x77 print_report+0x17f/0x47b kasan_report+0xad/0x130 string+0xd4/0x1c0 vsnprintf+0x500/0x840 seq_buf_vprintf+0x62/0xc0 trace_seq_printf+0x10e/0x1e0 print_type_string+0x90/0xa0 print_kprobe_event+0x16b/0x290 print_trace_line+0x451/0x8e0 s_show+0x72/0x1f0 seq_read_iter+0x58e/0x750 seq_read+0x115/0x160 vfs_read+0x11d/0x460 ksys_read+0xa9/0x130 do_syscall_64+0x3a/0x90 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7fc2e972ade2 Code: c0 e9 b2 fe ff ff 50 48 8d 3d b2 3f 0a 00 e8 05 f0 01 00 0f 1f 44 00 00 f3 0f 1e fa 64 8b 04 25 18 00 00 00 85 c0 75 10 0f 05 <48> 3d 00 f0 ff ff 77 56 c3 0f 1f 44 00 00 48 83 ec 28 48 89 54 24 RSP: 002b:00007ffc64e687c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 RAX: ffffffffffffffda RBX: 0000000000020000 RCX: 00007fc2e972ade2 RDX: 0000000000020000 RSI: 00007fc2e980d000 RDI: 0000000000000003 RBP: 00007fc2e980d000 R08: 00007fc2e980c010 R09: 0000000000000000 R10: 0000000000000022 R11: 0000000000000246 R12: 0000000000020f00 R13: 0000000000000003 R14: 0000000000020000 R15: 0000000000020000 </TASK> The buggy address belongs to the physical page: page:ffffea00017f6ec0 refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x5fdbb flags: 0xfffffc0000000(node=0|zone=1|lastcpupid=0x1fffff) raw: 000fffffc0000000 0000000000000000 ffffea00017f6ec8 0000000000000000 raw: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff88805fdbbe80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff88805fdbbf00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff >ffff88805fdbbf80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ^ ffff88805fdbc000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff88805fdbc080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ================================================================== This was found when Zheng Yejian sent a patch to convert the event type number assignment to use IDA, which gives the next available number, and this bug showed up in the fuzz testing by Yujie Liu and the kernel test robot. But after further analysis, I found that this behavior is the same as when the event type numbers go past the 16bit max (and the above shows that). As modules have a similar issue, but is dealt with by setting a "WAS_ENABLED" flag when a module event is enabled, and when the module is freed, if any of its events were enabled, the ring buffer that holds that event is also cleared, to prevent reading stale events. The same can be done for dynamic events. If any dynamic event that is being removed was enabled, then make sure the buffers they were enabled in are now cleared. Link: https://lkml.kernel.org/r/20221123171434.545706e3@gandalf.local.home Link: https://lore.kernel.org/all/20221110020319.1259291-1-zhengyejian1@huawei.co… Cc: stable(a)vger.kernel.org Cc: Andrew Morton <akpm(a)linux-foundation.org> Depends-on: e18eb8783ec49 ("tracing: Add tracing_reset_all_online_cpus_unlocked() function") Depends-on: 5448d44c38557 ("tracing: Add unified dynamic event framework") Depends-on: 6212dd29683ee ("tracing/kprobes: Use dyn_event framework for kprobe events") Depends-on: 065e63f951432 ("tracing: Only have rmmod clear buffers that its events were active in") Depends-on: 575380da8b469 ("tracing: Only clear trace buffer on module unload if event was traced") Fixes: 77b44d1b7c283 ("tracing/kprobes: Rename Kprobe-tracer to kprobe-event") Reported-by: Zheng Yejian <zhengyejian1(a)huawei.com> Reported-by: Yujie Liu <yujie.liu(a)intel.com> Reported-by: kernel test robot <yujie.liu(a)intel.com> Acked-by: Masami Hiramatsu (Google) <mhiramat(a)kernel.org> Signed-off-by: Steven Rostedt (Google) <rostedt(a)goodmis.org> diff --git a/kernel/trace/trace_dynevent.c b/kernel/trace/trace_dynevent.c index 154996684fb5..4376887e0d8a 100644 --- a/kernel/trace/trace_dynevent.c +++ b/kernel/trace/trace_dynevent.c @@ -118,6 +118,7 @@ int dyn_event_release(const char *raw_command, struct dyn_event_operations *type if (ret) break; } + tracing_reset_all_online_cpus(); mutex_unlock(&event_mutex); out: argv_free(argv); @@ -214,6 +215,7 @@ int dyn_events_release_all(struct dyn_event_operations *type) break; } out: + tracing_reset_all_online_cpus(); mutex_unlock(&event_mutex); return ret; diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c index 78cd19e31dba..f71ea6e79b3c 100644 --- a/kernel/trace/trace_events.c +++ b/kernel/trace/trace_events.c @@ -2880,7 +2880,10 @@ static int probe_remove_event_call(struct trace_event_call *call) * TRACE_REG_UNREGISTER. */ if (file->flags & EVENT_FILE_FL_ENABLED) - return -EBUSY; + goto busy; + + if (file->flags & EVENT_FILE_FL_WAS_ENABLED) + tr->clear_trace = true; /* * The do_for_each_event_file_safe() is * a double loop. After finding the call for this @@ -2893,6 +2896,12 @@ static int probe_remove_event_call(struct trace_event_call *call) __trace_remove_event_call(call); return 0; + busy: + /* No need to clear the trace now */ + list_for_each_entry(tr, &ftrace_trace_arrays, list) { + tr->clear_trace = false; + } + return -EBUSY; } /* Remove an event_call */

1 year, 10 months

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FAILED: patch "[PATCH] tracing: Free buffers when a used dynamic event is removed" failed to apply to 4.14-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 4.14-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. Possible dependencies: 4313e5a61304 ("tracing: Free buffers when a used dynamic event is removed") 5448d44c3855 ("tracing: Add unified dynamic event framework") thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 4313e5a613049dfc1819a6dfb5f94cf2caff9452 Mon Sep 17 00:00:00 2001 From: "Steven Rostedt (Google)" <rostedt(a)goodmis.org> Date: Wed, 23 Nov 2022 17:14:34 -0500 Subject: [PATCH] tracing: Free buffers when a used dynamic event is removed MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit After 65536 dynamic events have been added and removed, the "type" field of the event then uses the first type number that is available (not currently used by other events). A type number is the identifier of the binary blobs in the tracing ring buffer (known as events) to map them to logic that can parse the binary blob. The issue is that if a dynamic event (like a kprobe event) is traced and is in the ring buffer, and then that event is removed (because it is dynamic, which means it can be created and destroyed), if another dynamic event is created that has the same number that new event's logic on parsing the binary blob will be used. To show how this can be an issue, the following can crash the kernel: # cd /sys/kernel/tracing # for i in `seq 65536`; do echo 'p:kprobes/foo do_sys_openat2 $arg1:u32' > kprobe_events # done For every iteration of the above, the writing to the kprobe_events will remove the old event and create a new one (with the same format) and increase the type number to the next available on until the type number reaches over 65535 which is the max number for the 16 bit type. After it reaches that number, the logic to allocate a new number simply looks for the next available number. When an dynamic event is removed, that number is then available to be reused by the next dynamic event created. That is, once the above reaches the max number, the number assigned to the event in that loop will remain the same. Now that means deleting one dynamic event and created another will reuse the previous events type number. This is where bad things can happen. After the above loop finishes, the kprobes/foo event which reads the do_sys_openat2 function call's first parameter as an integer. # echo 1 > kprobes/foo/enable # cat /etc/passwd > /dev/null # cat trace cat-2211 [005] .... 2007.849603: foo: (do_sys_openat2+0x0/0x130) arg1=4294967196 cat-2211 [005] .... 2007.849620: foo: (do_sys_openat2+0x0/0x130) arg1=4294967196 cat-2211 [005] .... 2007.849838: foo: (do_sys_openat2+0x0/0x130) arg1=4294967196 cat-2211 [005] .... 2007.849880: foo: (do_sys_openat2+0x0/0x130) arg1=4294967196 # echo 0 > kprobes/foo/enable Now if we delete the kprobe and create a new one that reads a string: # echo 'p:kprobes/foo do_sys_openat2 +0($arg2):string' > kprobe_events And now we can the trace: # cat trace sendmail-1942 [002] ..... 530.136320: foo: (do_sys_openat2+0x0/0x240) arg1= cat-2046 [004] ..... 530.930817: foo: (do_sys_openat2+0x0/0x240) arg1="��" cat-2046 [004] ..... 530.930961: foo: (do_sys_openat2+0x0/0x240) arg1="��" cat-2046 [004] ..... 530.934278: foo: (do_sys_openat2+0x0/0x240) arg1="��" cat-2046 [004] ..... 530.934563: foo: (do_sys_openat2+0x0/0x240) arg1="��" bash-1515 [007] ..... 534.299093: foo: (do_sys_openat2+0x0/0x240) arg1="kkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkk��@��4Z��;Y��U And dmesg has: ================================================================== BUG: KASAN: use-after-free in string+0xd4/0x1c0 Read of size 1 at addr ffff88805fdbbfa0 by task cat/2049 CPU: 0 PID: 2049 Comm: cat Not tainted 6.1.0-rc6-test+ #641 Hardware name: Hewlett-Packard HP Compaq Pro 6300 SFF/339A, BIOS K01 v03.03 07/14/2016 Call Trace: <TASK> dump_stack_lvl+0x5b/0x77 print_report+0x17f/0x47b kasan_report+0xad/0x130 string+0xd4/0x1c0 vsnprintf+0x500/0x840 seq_buf_vprintf+0x62/0xc0 trace_seq_printf+0x10e/0x1e0 print_type_string+0x90/0xa0 print_kprobe_event+0x16b/0x290 print_trace_line+0x451/0x8e0 s_show+0x72/0x1f0 seq_read_iter+0x58e/0x750 seq_read+0x115/0x160 vfs_read+0x11d/0x460 ksys_read+0xa9/0x130 do_syscall_64+0x3a/0x90 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7fc2e972ade2 Code: c0 e9 b2 fe ff ff 50 48 8d 3d b2 3f 0a 00 e8 05 f0 01 00 0f 1f 44 00 00 f3 0f 1e fa 64 8b 04 25 18 00 00 00 85 c0 75 10 0f 05 <48> 3d 00 f0 ff ff 77 56 c3 0f 1f 44 00 00 48 83 ec 28 48 89 54 24 RSP: 002b:00007ffc64e687c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 RAX: ffffffffffffffda RBX: 0000000000020000 RCX: 00007fc2e972ade2 RDX: 0000000000020000 RSI: 00007fc2e980d000 RDI: 0000000000000003 RBP: 00007fc2e980d000 R08: 00007fc2e980c010 R09: 0000000000000000 R10: 0000000000000022 R11: 0000000000000246 R12: 0000000000020f00 R13: 0000000000000003 R14: 0000000000020000 R15: 0000000000020000 </TASK> The buggy address belongs to the physical page: page:ffffea00017f6ec0 refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x5fdbb flags: 0xfffffc0000000(node=0|zone=1|lastcpupid=0x1fffff) raw: 000fffffc0000000 0000000000000000 ffffea00017f6ec8 0000000000000000 raw: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff88805fdbbe80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff88805fdbbf00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff >ffff88805fdbbf80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ^ ffff88805fdbc000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff88805fdbc080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ================================================================== This was found when Zheng Yejian sent a patch to convert the event type number assignment to use IDA, which gives the next available number, and this bug showed up in the fuzz testing by Yujie Liu and the kernel test robot. But after further analysis, I found that this behavior is the same as when the event type numbers go past the 16bit max (and the above shows that). As modules have a similar issue, but is dealt with by setting a "WAS_ENABLED" flag when a module event is enabled, and when the module is freed, if any of its events were enabled, the ring buffer that holds that event is also cleared, to prevent reading stale events. The same can be done for dynamic events. If any dynamic event that is being removed was enabled, then make sure the buffers they were enabled in are now cleared. Link: https://lkml.kernel.org/r/20221123171434.545706e3@gandalf.local.home Link: https://lore.kernel.org/all/20221110020319.1259291-1-zhengyejian1@huawei.co… Cc: stable(a)vger.kernel.org Cc: Andrew Morton <akpm(a)linux-foundation.org> Depends-on: e18eb8783ec49 ("tracing: Add tracing_reset_all_online_cpus_unlocked() function") Depends-on: 5448d44c38557 ("tracing: Add unified dynamic event framework") Depends-on: 6212dd29683ee ("tracing/kprobes: Use dyn_event framework for kprobe events") Depends-on: 065e63f951432 ("tracing: Only have rmmod clear buffers that its events were active in") Depends-on: 575380da8b469 ("tracing: Only clear trace buffer on module unload if event was traced") Fixes: 77b44d1b7c283 ("tracing/kprobes: Rename Kprobe-tracer to kprobe-event") Reported-by: Zheng Yejian <zhengyejian1(a)huawei.com> Reported-by: Yujie Liu <yujie.liu(a)intel.com> Reported-by: kernel test robot <yujie.liu(a)intel.com> Acked-by: Masami Hiramatsu (Google) <mhiramat(a)kernel.org> Signed-off-by: Steven Rostedt (Google) <rostedt(a)goodmis.org> diff --git a/kernel/trace/trace_dynevent.c b/kernel/trace/trace_dynevent.c index 154996684fb5..4376887e0d8a 100644 --- a/kernel/trace/trace_dynevent.c +++ b/kernel/trace/trace_dynevent.c @@ -118,6 +118,7 @@ int dyn_event_release(const char *raw_command, struct dyn_event_operations *type if (ret) break; } + tracing_reset_all_online_cpus(); mutex_unlock(&event_mutex); out: argv_free(argv); @@ -214,6 +215,7 @@ int dyn_events_release_all(struct dyn_event_operations *type) break; } out: + tracing_reset_all_online_cpus(); mutex_unlock(&event_mutex); return ret; diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c index 78cd19e31dba..f71ea6e79b3c 100644 --- a/kernel/trace/trace_events.c +++ b/kernel/trace/trace_events.c @@ -2880,7 +2880,10 @@ static int probe_remove_event_call(struct trace_event_call *call) * TRACE_REG_UNREGISTER. */ if (file->flags & EVENT_FILE_FL_ENABLED) - return -EBUSY; + goto busy; + + if (file->flags & EVENT_FILE_FL_WAS_ENABLED) + tr->clear_trace = true; /* * The do_for_each_event_file_safe() is * a double loop. After finding the call for this @@ -2893,6 +2896,12 @@ static int probe_remove_event_call(struct trace_event_call *call) __trace_remove_event_call(call); return 0; + busy: + /* No need to clear the trace now */ + list_for_each_entry(tr, &ftrace_trace_arrays, list) { + tr->clear_trace = false; + } + return -EBUSY; } /* Remove an event_call */

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FAILED: patch "[PATCH] mmc: mtk-sd: Fix missing clk_disable_unprepare in" failed to apply to 5.15-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 5.15-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. Possible dependencies: c61bfb1cb63d ("mmc: mtk-sd: Fix missing clk_disable_unprepare in msdc_of_clock_parse()") thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From c61bfb1cb63ddab52b31cf5f1924688917e61fad Mon Sep 17 00:00:00 2001 From: Gaosheng Cui <cuigaosheng1(a)huawei.com> Date: Fri, 25 Nov 2022 17:01:41 +0800 Subject: [PATCH] mmc: mtk-sd: Fix missing clk_disable_unprepare in msdc_of_clock_parse() The clk_disable_unprepare() should be called in the error handling of devm_clk_bulk_get_optional, fix it by replacing devm_clk_get_optional and clk_prepare_enable by devm_clk_get_optional_enabled. Fixes: f5eccd94b63f ("mmc: mediatek: Add subsys clock control for MT8192 msdc") Signed-off-by: Gaosheng Cui <cuigaosheng1(a)huawei.com> Cc: stable(a)vger.kernel.org Link: https://lore.kernel.org/r/20221125090141.3626747-1-cuigaosheng1@huawei.com Signed-off-by: Ulf Hansson <ulf.hansson(a)linaro.org> diff --git a/drivers/mmc/host/mtk-sd.c b/drivers/mmc/host/mtk-sd.c index df941438aef5..26bc59b5a7cc 100644 --- a/drivers/mmc/host/mtk-sd.c +++ b/drivers/mmc/host/mtk-sd.c @@ -2588,13 +2588,11 @@ static int msdc_of_clock_parse(struct platform_device *pdev, return PTR_ERR(host->src_clk_cg); } - host->sys_clk_cg = devm_clk_get_optional(&pdev->dev, "sys_cg"); + /* If present, always enable for this clock gate */ + host->sys_clk_cg = devm_clk_get_optional_enabled(&pdev->dev, "sys_cg"); if (IS_ERR(host->sys_clk_cg)) host->sys_clk_cg = NULL; - /* If present, always enable for this clock gate */ - clk_prepare_enable(host->sys_clk_cg); - host->bulk_clks[0].id = "pclk_cg"; host->bulk_clks[1].id = "axi_cg"; host->bulk_clks[2].id = "ahb_cg";

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Linux-stable-mirror December 2022