Staging: comedi: fix signal handling in read and write
Federico Vaga [Sat, 29 Oct 2011 07:47:39 +0000 (09:47 +0200)]
commit 6a9ce6b654e491981f6ef7e214cbd4f63e033848 upstream.

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

Acked-by: Alessandro Rubini <rubini@gnudd.com>
Signed-off-by: Federico Vaga <federico.vaga@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/staging/comedi/comedi_fops.c

index bf55cce..b347cda 100644 (file)
@@ -1673,11 +1673,11 @@ static ssize_t comedi_write(struct file *file, const char __user *buf,
                                retval = -EAGAIN;
                                break;
                        }
+                       schedule();
                        if (signal_pending(current)) {
                                retval = -ERESTARTSYS;
                                break;
                        }
-                       schedule();
                        if (!s->busy)
                                break;
                        if (s->busy != file) {
@@ -1780,11 +1780,11 @@ static ssize_t comedi_read(struct file *file, char __user *buf, size_t nbytes,
                                retval = -EAGAIN;
                                break;
                        }
+                       schedule();
                        if (signal_pending(current)) {
                                retval = -ERESTARTSYS;
                                break;
                        }
-                       schedule();
                        if (!s->busy) {
                                retval = 0;
                                break;