diff options
| author | Hugh Dickins <hughd@google.com> | 2014-06-04 16:05:33 -0700 |
|---|---|---|
| committer | Ben Hutchings <ben@decadent.org.uk> | 2014-07-11 13:33:46 +0100 |
| commit | e3ffaedcd935237fa5f1d820cb6ad33810593079 (patch) | |
| tree | 2bc7bef8e0cdf8c760187d44bfa13add2e1f2293 /mm | |
| parent | ba1ef838a9e275933683edbd08b6e2226f16e351 (diff) | |
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>
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
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 9ac405ba91df..ae27d95072c8 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 (mutex_is_locked(&anon_vma->root->mutex)) { anon_vma_lock(anon_vma); anon_vma_unlock(anon_vma); @@ -434,8 +435,9 @@ 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(); @@ -485,9 +487,9 @@ struct anon_vma *page_lock_anon_vma(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 */ |