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| author | Vishal Moola (Oracle) <vishal.moola@gmail.com> | 2024-09-14 12:41:18 -0700 |
|---|---|---|
| committer | Andrew Morton <akpm@linux-foundation.org> | 2024-09-17 00:58:04 -0700 |
| commit | 2a058ab3286d6475b2082b90c2d2182d2fea4b39 (patch) | |
| tree | e521b1aa290facd3b3dc9d63a662be1520450aca /mm/internal.h | |
| parent | b4afe4183ec77f230851ea139d91e5cf2644c68b (diff) | |
| download | lwn-2a058ab3286d6475b2082b90c2d2182d2fea4b39.tar.gz lwn-2a058ab3286d6475b2082b90c2d2182d2fea4b39.zip | |
mm: change vmf_anon_prepare() to __vmf_anon_prepare()
Some callers of vmf_anon_prepare() may not want us to release the per-VMA
lock ourselves. Rename vmf_anon_prepare() to __vmf_anon_prepare() and let
the callers drop the lock when desired.
Also, make vmf_anon_prepare() a wrapper that releases the per-VMA lock
itself for any callers that don't care.
This is in preparation to fix this bug reported by syzbot:
https://lore.kernel.org/linux-mm/00000000000067c20b06219fbc26@google.com/
Link: https://lkml.kernel.org/r/20240914194243.245-1-vishal.moola@gmail.com
Fixes: 9acad7ba3e25 ("hugetlb: use vmf_anon_prepare() instead of anon_vma_prepare()")
Reported-by: syzbot+2dab93857ee95f2eeb08@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/linux-mm/00000000000067c20b06219fbc26@google.com/
Signed-off-by: Vishal Moola (Oracle) <vishal.moola@gmail.com>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'mm/internal.h')
| -rw-r--r-- | mm/internal.h | 11 |
1 files changed, 10 insertions, 1 deletions
diff --git a/mm/internal.h b/mm/internal.h index b4d86436565b..a963f67d3452 100644 --- a/mm/internal.h +++ b/mm/internal.h @@ -310,7 +310,16 @@ static inline void wake_throttle_isolated(pg_data_t *pgdat) wake_up(wqh); } -vm_fault_t vmf_anon_prepare(struct vm_fault *vmf); +vm_fault_t __vmf_anon_prepare(struct vm_fault *vmf); +static inline vm_fault_t vmf_anon_prepare(struct vm_fault *vmf) +{ + vm_fault_t ret = __vmf_anon_prepare(vmf); + + if (unlikely(ret & VM_FAULT_RETRY)) + vma_end_read(vmf->vma); + return ret; +} + vm_fault_t do_swap_page(struct vm_fault *vmf); void folio_rotate_reclaimable(struct folio *folio); bool __folio_end_writeback(struct folio *folio); |