diff options
| author | Hugh Dickins <hughd@google.com> | 2014-06-04 16:05:33 -0700 |
|---|---|---|
| committer | Jiri Slaby <jslaby@suse.cz> | 2014-07-02 12:06:11 +0200 |
| commit | 6e74114b58ad6f474bb591547ab7d766488251a2 (patch) | |
| tree | 49a74e4eb13488accf46113bc42be76e5edb1107 /mm | |
| parent | 79035696ef6d567b6431e446cdaa01b7951f76b2 (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>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
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 91ab22878103..4271107aa46e 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 */ |