From e50c85f4ebf559a3bac4817b41074c43d4691779 Mon Sep 17 00:00:00 2001
From: Eric Anholt <eric@anholt.net>
Date: Fri, 26 Oct 2018 17:47:30 -0700
Subject: [PATCH xserver] Fix segfault on probing a non-PCI platform device on
 a system with PCI.

Some Broadcom set-top-box boards have PCI busses, but the GPU is still
probed through DT.  We would dereference a null busid here in that
case.

Signed-off-by: Eric Anholt <eric@anholt.net>
---
 hw/xfree86/common/xf86platformBus.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/hw/xfree86/common/xf86platformBus.c b/hw/xfree86/common/xf86platformBus.c
index cef47da03d..dadbac6c8f 100644
--- a/hw/xfree86/common/xf86platformBus.c
+++ b/hw/xfree86/common/xf86platformBus.c
@@ -289,7 +289,7 @@ xf86platformProbe(void)
     for (i = 0; i < xf86_num_platform_devices; i++) {
         char *busid = xf86_platform_odev_attributes(i)->busid;
 
-        if (pci && (strncmp(busid, "pci:", 4) == 0)) {
+        if (pci && busid && (strncmp(busid, "pci:", 4) == 0)) {
             platform_find_pci_info(&xf86_platform_devices[i], busid);
         }
 
-- 
2.21.0