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>
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@ -733,12 +733,14 @@ static void kill_fasync_rcu(struct fasync_struct *fa, int sig, int band)
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{
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while (fa) {
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struct fown_struct *fown;
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unsigned long flags;
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if (fa->magic != FASYNC_MAGIC) {
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printk(KERN_ERR "kill_fasync: bad magic number in "
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"fasync_struct!\n");
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return;
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}
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spin_lock(&fa->fa_lock);
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spin_lock_irqsave(&fa->fa_lock, flags);
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if (fa->fa_file) {
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fown = &fa->fa_file->f_owner;
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/* Don't send SIGURG to processes which have not set a
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@ -747,7 +749,7 @@ static void kill_fasync_rcu(struct fasync_struct *fa, int sig, int band)
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if (!(sig == SIGURG && fown->signum == 0))
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send_sigio(fown, fa->fa_fd, band);
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}
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spin_unlock(&fa->fa_lock);
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spin_unlock_irqrestore(&fa->fa_lock, flags);
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fa = rcu_dereference(fa->fa_next);
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}
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}
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