From 201d3dfa4da10ac45b260320b94e2f2f0e10d687 Mon Sep 17 00:00:00 2001 From: Oleg Nesterov Date: Fri, 9 Aug 2013 17:19:13 +0200 Subject: dlm: kill the unnecessary and wrong device_close()->recalc_sigpending() device_close()->recalc_sigpending() is not needed, sigprocmask() takes care of TIF_SIGPENDING correctly. And without ->siglock it is racy and wrong, it can wrongly clear TIF_SIGPENDING and miss a signal. But even with this patch device_close() is still buggy: 1. sigprocmask() should not be used, we have set_task_blocked(), but this is minor. 2. We should never block SIGKILL or SIGSTOP, and this is what the code tries to do. 3. This can't protect against SIGKILL or SIGSTOP anyway. Another thread can do signal_wake_up(), say, do_signal_stop() or complete_signal() or debugger. 4. sigprocmask(SIG_BLOCK, allsigs) doesn't necessarily clears TIF_SIGPENDING, say, freezing() or ->jobctl. 5. device_write() looks equally wrong by the same reason. Looks like, this tries to protect some wait_event_interruptible() logic from signals, it should be turned into uninterruptible wait. Or we need to implement something like signals_stop/start for such a use-case. Signed-off-by: Oleg Nesterov Signed-off-by: Linus Torvalds --- fs/dlm/user.c | 1 - 1 file changed, 1 deletion(-) (limited to 'fs/dlm') diff --git a/fs/dlm/user.c b/fs/dlm/user.c index 911649a..8121491 100644 --- a/fs/dlm/user.c +++ b/fs/dlm/user.c @@ -686,7 +686,6 @@ static int device_close(struct inode *inode, struct file *file) device_remove_lockspace() */ sigprocmask(SIG_SETMASK, &tmpsig, NULL); - recalc_sigpending(); return 0; } -- cgit v1.1