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| author | Andrew Morton <akpm@linux-foundation.org> | 2010-06-29 15:05:42 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2010-06-29 15:29:32 -0700 |
| commit | f4985dc714d7ab1920c5aa502b7f4073fa1b4177 (patch) | |
| tree | 4e8385c3d0c95f02623f5712a875742664701822 /fs/fcntl.c | |
| parent | fb967ecc584c20c74a007de749ca597068b0fcac (diff) | |
| download | lwn-f4985dc714d7ab1920c5aa502b7f4073fa1b4177.tar.gz lwn-f4985dc714d7ab1920c5aa502b7f4073fa1b4177.zip | |
fs/fcntl.c:kill_fasync_rcu() fa_lock must be IRQ-safe
Fix a lockdep-splat-causing regression introduced by commit 989a2979205d
("fasync: RCU and fine grained locking").
kill_fasync() can be called from both process and hard-irq context, so
fa_lock must be taken with IRQs disabled.
Addresses https://bugzilla.kernel.org/show_bug.cgi?id=16230
Reported-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Reported-by: Dominik Brodowski <linux@dominikbrodowski.net>
Tested-by: Dominik Brodowski <linux@dominikbrodowski.net>
Cc: Maciej Rutecki <maciej.rutecki@gmail.com>
Acked-by: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Lai Jiangshan <laijs@cn.fujitsu.com>
Cc: "David S. Miller" <davem@davemloft.net>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'fs/fcntl.c')
| -rw-r--r-- | fs/fcntl.c | 6 |
1 files changed, 4 insertions, 2 deletions
diff --git a/fs/fcntl.c b/fs/fcntl.c index 51e11bf5708f..9d175d623aab 100644 --- a/fs/fcntl.c +++ b/fs/fcntl.c @@ -733,12 +733,14 @@ static void kill_fasync_rcu(struct fasync_struct *fa, int sig, int band) { while (fa) { struct fown_struct *fown; + unsigned long flags; + if (fa->magic != FASYNC_MAGIC) { printk(KERN_ERR "kill_fasync: bad magic number in " "fasync_struct!\n"); return; } - spin_lock(&fa->fa_lock); + spin_lock_irqsave(&fa->fa_lock, flags); if (fa->fa_file) { fown = &fa->fa_file->f_owner; /* Don't send SIGURG to processes which have not set a @@ -747,7 +749,7 @@ static void kill_fasync_rcu(struct fasync_struct *fa, int sig, int band) if (!(sig == SIGURG && fown->signum == 0)) send_sigio(fown, fa->fa_fd, band); } - spin_unlock(&fa->fa_lock); + spin_unlock_irqrestore(&fa->fa_lock, flags); fa = rcu_dereference(fa->fa_next); } } |