From f20a6709eaa7be3f2e3e4d0bf70e346781427c42 Mon Sep 17 00:00:00 2001
From: Martin Peres <martin.peres@linux.intel.com>
Date: Fri, 17 Jul 2015 17:21:26 +0300
Subject: [PATCH] os: make sure the clientsWritable fd_set is initialized
 before use

In WaitForSomething(), the fd_set clientsWritable may be used unitialized when
the boolean AnyClientsWriteBlocked is set in the WakeupHandler().

Fix this by zeroing the fd_set at the begining of WaitForSomething(). In this
case, the bottom part of the loop will not do any work but the next call to
select will result in the execution of the right codepath. This is exactly what
we want because we need to know the writable clients before handling them.

Reported-by: Karol Herbst <freedesktop@karolherbst.de>
Reported-by: Tobias Klausmann <tobias.klausmann@mni.thm.de>
Signed-off-by: Martin Peres <martin.peres@linux.intel.com>
Tested-by: Martin Peres <martin.peres@linux.intel.com>
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=91316
Cc: Ilia Mirkin  <imirkin@alum.mit.edu>
Cc: Martin Peres <martin.peres@linux.intel.com>
Cc: Olivier Fourdan <ofourdan@redhat.com
Cc: Adam Jackson <ajax@redhat.com>
Cc: Alan Coopersmith <alan.coopersmith@oracle.com
Cc: Chris Wilson <chris@chris-wilson.co.uk>
---
 os/WaitFor.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/os/WaitFor.c b/os/WaitFor.c
index 431f1a6..993c14e 100644
--- a/os/WaitFor.c
+++ b/os/WaitFor.c
@@ -158,6 +158,7 @@ WaitForSomething(int *pClientsReady)
     Bool someReady = FALSE;
 
     FD_ZERO(&clientsReadable);
+    FD_ZERO(&clientsWritable);
 
     if (nready)
         SmartScheduleStopTimer();
-- 
2.4.5