[PATCH] Adds null check for DisplayStatus (wasRe: [Qemu-devel] [6344] graphical_console_init change (Stefano Stabellini)

[Shin-ichiro KAWASAKI <kawasaki@juno.dti.ne.jp>]

Shin-ichiro KAWASAKI wrote:
> Hi.
> 
> Anthony Liguori wrote:
>> Revision: 6344
>>           http://svn.sv.gnu.org/viewvc/?view=rev&root=qemu&revision=6344
>> Author:   aliguori
>> Date:     2009-01-16 19:04:14 +0000 (Fri, 16 Jan 2009)
>>
>> Log Message:
>> -----------
>> graphical_console_init change (Stefano Stabellini)
>>
> (snip)
> 
>> Modified: trunk/vl.c
>> ===================================================================
>> --- trunk/vl.c    2009-01-16 18:13:32 UTC (rev 6343)
>> +++ trunk/vl.c    2009-01-16 19:04:14 UTC (rev 6344)
> (snip)
>> +    /* just use the first displaystate for the moment */
>> +    ds = display_state;
>>      /* terminal init */
>> -    memset(&display_state, 0, sizeof(display_state));
>> -    ds->surface = qemu_create_displaysurface(640, 480, 32, 640 * 4);
>>      if (nographic) {
>>          if (curses) {
>>              fprintf(stderr, "fatal: -nographic can't be used with 
>> -curses\n");
> 
> This commit seems to cause segmentation fault for boards which has no 
> graphics
> display.  I saw the fault when I working with my SE7750 board support 
> patch, and
> invoking with -nographic options. The fault happens in 
> dump_display_init(ds) within the 'if (nographic)' block quoted above.  
> The argument ds is NULL because
> no graphic board initialize it, I guess.  Some null check for ds or 
> dummy ds might
> be needed, for such cases.

I'm sending the patch which solves the problem above.
Could anyone evaluate it?

Regards,
Shin-ichiro KAWASAKI


Signed-off-by: Shin-ichiro KAWASAKI <kawasaki@juno.dti.ne.jp>

Index: trunk/vl.c
===================================================================
--- trunk/vl.c	(revision 6365)
+++ trunk/vl.c	(working copy)
@@ -5544,7 +5544,8 @@
             exit(1);
         }
         /* nearly nothing to do */
-        dumb_display_init(ds);
+	if (ds)
+	    dumb_display_init(ds);
     } else { 
 #if defined(CONFIG_CURSES)
             if (curses) {
@@ -5568,18 +5569,21 @@
 #endif
             }
     }
-    dpy_resize(ds);
+    if (ds) {
+	dpy_resize(ds);
 
-    dcl = ds->listeners;
-    while (dcl != NULL) {
-        if (dcl->dpy_refresh != NULL) {
-            ds->gui_timer = qemu_new_timer(rt_clock, gui_update, ds);
-            qemu_mod_timer(ds->gui_timer, qemu_get_clock(rt_clock));
-        }
-        dcl = dcl->next;
+	dcl = ds->listeners;
+	while (dcl != NULL) {
+	    if (dcl->dpy_refresh != NULL) {
+		ds->gui_timer = qemu_new_timer(rt_clock, gui_update, ds);
+		qemu_mod_timer(ds->gui_timer, qemu_get_clock(rt_clock));
+	    }
+	    dcl = dcl->next;
+	}
     }
 
-    text_consoles_set_display(display_state);
+    if (display_state)
+	text_consoles_set_display(display_state);
 
     if (monitor_device && monitor_hd)
         monitor_init(monitor_hd, !nographic);