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| author | Jann Horn <jannh@google.com> | 2022-11-25 22:37:13 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2023-01-18 09:26:04 +0100 |
| commit | 42adf3fe46e5aa9b387ad3f2bff59e4c2b236889 (patch) | |
| tree | 6bda2e7f0167d65f4495ed5f92773ff83975b43c /include | |
| parent | 7ebf22461c74dff22152d7fc5dd556e86231041e (diff) | |
| download | linux-42adf3fe46e5aa9b387ad3f2bff59e4c2b236889.tar.gz linux-42adf3fe46e5aa9b387ad3f2bff59e4c2b236889.tar.bz2 linux-42adf3fe46e5aa9b387ad3f2bff59e4c2b236889.zip | |
mm/khugepaged: fix GUP-fast interaction by sending IPI
commit 2ba99c5e08812494bc57f319fb562f527d9bacd8 upstream.
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@google.com>
Reviewed-by: Yang Shi <shy828301@gmail.com>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
[manual backport: two of the three places in khugepaged that can free
ptes were refactored into a common helper between 5.15 and 6.0;
TLB flushing was refactored between 5.4 and 5.10;
TLB flushing was refactored between 4.19 and 5.4;
pmd collapse for PTE-mapped THP was only added in 5.4;
ugly hack for s390 in <=4.19 and arm]
Signed-off-by: Jann Horn <jannh@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'include')
| -rw-r--r-- | include/asm-generic/tlb.h | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/include/asm-generic/tlb.h b/include/asm-generic/tlb.h index 5e7e4aaf36c5..43409a047480 100644 --- a/include/asm-generic/tlb.h +++ b/include/asm-generic/tlb.h @@ -60,6 +60,12 @@ struct mmu_table_batch { extern void tlb_table_flush(struct mmu_gather *tlb); extern void tlb_remove_table(struct mmu_gather *tlb, void *table); +void tlb_remove_table_sync_one(void); + +#else + +static inline void tlb_remove_table_sync_one(void) { } + #endif /* |