From: Ian Abbott <abbotti@mev.co.uk>
Date: Tue, 1 Nov 2011 09:49:29 +0000 (+0000)
Subject: Fix signal handling in read and write
X-Git-Url: http://git.tremily.us/?a=commitdiff_plain;h=549d8aed98c2de6326e6594a8cd020a84ff45726;p=comedi.git

Fix signal handling in read and write

Follow bug-fix by Federico Vaga on the Linux "staging" version:

After sleeping on a wait queue, signal_pending(current) should be
checked (not before sleeping).
---

diff --git a/comedi/comedi_fops.c b/comedi/comedi_fops.c
index 0b29573b..210eb416 100644
--- a/comedi/comedi_fops.c
+++ b/comedi/comedi_fops.c
@@ -1682,11 +1682,11 @@ static ssize_t comedi_write(struct file *file, const char *buf, size_t nbytes,
 				retval = -EAGAIN;
 				break;
 			}
+			schedule();
 			if (signal_pending(current)) {
 				retval = -ERESTARTSYS;
 				break;
 			}
-			schedule();
 			if (!s->busy) {
 				break;
 			}
@@ -1784,11 +1784,11 @@ static ssize_t comedi_read(struct file *file, char *buf, size_t nbytes,
 				retval = -EAGAIN;
 				break;
 			}
+			schedule();
 			if (signal_pending(current)) {
 				retval = -ERESTARTSYS;
 				break;
 			}
-			schedule();
 			if (!s->busy) {
 				retval = 0;
 				break;