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| author | Hugh Dickins <hughd@google.com> | 2014-06-04 16:05:33 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2014-06-30 20:11:53 -0700 |
| commit | 9164f428a751ef1d4d2c8f361943a09ae2a9c98e (patch) | |
| tree | 2e860f96d3a01ac4a0c0ca0c08b5636b26dc84e9 /mm | |
| parent | 981433901d8e675a8441bdc73beb70d39b9dc387 (diff) | |
| download | lwn-9164f428a751ef1d4d2c8f361943a09ae2a9c98e.tar.gz lwn-9164f428a751ef1d4d2c8f361943a09ae2a9c98e.zip | |
mm: fix sleeping function warning from __put_anon_vma
commit 7f39dda9d86fb4f4f17af0de170decf125726f8c upstream.
Trinity reports BUG:
sleeping function called from invalid context at kernel/locking/rwsem.c:47
in_atomic(): 0, irqs_disabled(): 0, pid: 5787, name: trinity-c27
__might_sleep < down_write < __put_anon_vma < page_get_anon_vma <
migrate_pages < compact_zone < compact_zone_order < try_to_compact_pages ..
Right, since conversion to mutex then rwsem, we should not put_anon_vma()
from inside an rcu_read_lock()ed section: fix the two places that did so.
And add might_sleep() to anon_vma_free(), as suggested by Peter Zijlstra.
Fixes: 88c22088bf23 ("mm: optimize page_lock_anon_vma() fast-path")
Reported-by: Dave Jones <davej@redhat.com>
Signed-off-by: Hugh Dickins <hughd@google.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'mm')
| -rw-r--r-- | mm/rmap.c | 8 |
1 files changed, 5 insertions, 3 deletions
diff --git a/mm/rmap.c b/mm/rmap.c index 5d91bb71e751..cdbd31285cf6 100644 --- a/mm/rmap.c +++ b/mm/rmap.c @@ -103,6 +103,7 @@ static inline void anon_vma_free(struct anon_vma *anon_vma) * LOCK should suffice since the actual taking of the lock must * happen _before_ what follows. */ + might_sleep(); if (rwsem_is_locked(&anon_vma->root->rwsem)) { anon_vma_lock_write(anon_vma); anon_vma_unlock_write(anon_vma); @@ -426,8 +427,9 @@ struct anon_vma *page_get_anon_vma(struct page *page) * above cannot corrupt). */ if (!page_mapped(page)) { + rcu_read_unlock(); put_anon_vma(anon_vma); - anon_vma = NULL; + return NULL; } out: rcu_read_unlock(); @@ -477,9 +479,9 @@ struct anon_vma *page_lock_anon_vma_read(struct page *page) } if (!page_mapped(page)) { + rcu_read_unlock(); put_anon_vma(anon_vma); - anon_vma = NULL; - goto out; + return NULL; } /* we pinned the anon_vma, its safe to sleep */ |