[PATCH 4/8] OProfile update

[John Levon]

If there's are multiple tasks sleeping inside the read routine ever, this is necessary.

diff -Naur -X dontdiff linux-cvs/drivers/oprofile/event_buffer.c linux-me/drivers/oprofile/event_buffer.c
--- linux-cvs/drivers/oprofile/event_buffer.c	2002-12-21 19:18:20.000000000 +0000
+++ linux-me/drivers/oprofile/event_buffer.c	2003-04-29 01:09:35.000000000 +0100
@@ -151,11 +151,15 @@
 	if (count != max || *offset)
 		return -EINVAL;
 
-	/* wait for the event buffer to fill up with some data */
 	wait_event_interruptible(buffer_wait, atomic_read(&buffer_ready));
+
 	if (signal_pending(current))
 		return -EINTR;
 
+	/* can't currently happen */
+	if (!atomic_read(&buffer_ready))
+		return -EAGAIN;
+
 	down(&buffer_sem);
 
 	atomic_set(&buffer_ready, 0);