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author | Catalin Marinas <catalin.marinas@arm.com> | 2009-07-29 16:26:57 +0100 |
---|---|---|
committer | Linus Torvalds <torvalds@linux-foundation.org> | 2009-07-29 12:34:58 -0700 |
commit | f5886c7f96f2542382d3a983c5f13e03d7fc5259 (patch) | |
tree | 75c5e09bdd8726fa3fa0c2cc3b764d523e5160f2 /mm | |
parent | 84210aeb4a6a77de8a3067b121026bad630cd3da (diff) | |
download | lwn-f5886c7f96f2542382d3a983c5f13e03d7fc5259.tar.gz lwn-f5886c7f96f2542382d3a983c5f13e03d7fc5259.zip |
kmemleak: Protect the seq start/next/stop sequence by rcu_read_lock()
Objects passed to kmemleak_seq_next() have an incremented reference
count (hence not freed) but they may point via object_list.next to
other freed objects. To avoid this, the whole start/next/stop sequence
must be protected by rcu_read_lock().
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm')
-rw-r--r-- | mm/kmemleak.c | 4 |
1 files changed, 1 insertions, 3 deletions
diff --git a/mm/kmemleak.c b/mm/kmemleak.c index 5aabd41ffb8f..487267310a84 100644 --- a/mm/kmemleak.c +++ b/mm/kmemleak.c @@ -1217,7 +1217,6 @@ static void *kmemleak_seq_start(struct seq_file *seq, loff_t *pos) } object = NULL; out: - rcu_read_unlock(); return object; } @@ -1233,13 +1232,11 @@ static void *kmemleak_seq_next(struct seq_file *seq, void *v, loff_t *pos) ++(*pos); - rcu_read_lock(); list_for_each_continue_rcu(n, &object_list) { next_obj = list_entry(n, struct kmemleak_object, object_list); if (get_object(next_obj)) break; } - rcu_read_unlock(); put_object(prev_obj); return next_obj; @@ -1255,6 +1252,7 @@ static void kmemleak_seq_stop(struct seq_file *seq, void *v) * kmemleak_seq_start may return ERR_PTR if the scan_mutex * waiting was interrupted, so only release it if !IS_ERR. */ + rcu_read_unlock(); mutex_unlock(&scan_mutex); if (v) put_object(v); |