[Bug 19948] New: segfault in mode selection -- VidModeGetNumOfModes()

[bugzilla-daemon at freedesktop.org]

http://bugs.freedesktop.org/show_bug.cgi?id=19948

           Summary: segfault in mode selection -- VidModeGetNumOfModes()
           Product: xorg
           Version: unspecified
          Platform: x86 (IA32)
               URL: https://bugs.edge.launchpad.net/ubuntu/+source/xorg-
                    server/+bug/300310
        OS/Version: Linux (All)
            Status: NEW
          Severity: major
          Priority: high
         Component: Driver/Radeon
        AssignedTo: xorg-driver-ati at lists.x.org
        ReportedBy: bryce at canonical.com
         QAContact: xorg-team at lists.x.org


Created an attachment (id=22567)
 --> (http://bugs.freedesktop.org/attachment.cgi?id=22567)
Xorg.0.log.old

Forwarding this bug from a Ubuntu reporter:
https://bugs.edge.launchpad.net/ubuntu/+source/xorg-server/+bug/300310

[Problem]
xserver is crashing in video mode selection when using -ati (-fglrx is ok) when
starting an SDL application.  Maybe it just needs a check for the NULL pointer?

[Backtrace]
#0 VidModeGetFirstModeline (scrnIndex=<value optimized out>,
mode=0x7fff7e25b778,
    dotClock=0x7fff7e25b784) at ../../../../hw/xfree86/common/xf86VidMode.c:229
        pScrn = (ScrnInfoPtr) 0x25925b0
#1 0x0000000000485a32 in VidModeGetNumOfModes (scrnIndex=39526608)
    at ../../../../hw/xfree86/common/xf86VidMode.c:451
        mode = (pointer) 0x0
        dotClock = 0
        nummodes = 0
#2 0x00007f82738f5031 in ProcXF86VidModeGetAllModeLines (client=0x289ea60)
    at ../../../../../hw/xfree86/dixmods/extmod/xf86vmode.c:534
        rep = {type = 40 '(', pad1 = 69 'E', sequenceNumber = 126, length = 0,
modecount = 4527588,
  pad2 = 0, pad3 = 0, pad4 = 0, pad5 = 42592864, pad6 = 0}
        mdinf = {dotclock = 0, hdisplay = 0, hsyncstart = 0, hsyncend = 0,
htotal = 0, hskew = 0,
  vdisplay = 0, vsyncstart = 0, vsyncend = 0, vtotal = 0, pad1 = 16751, flags =
0, reserved1 = 0,
  reserved2 = 0, reserved3 = 39886816, privsize = 0}
        oldmdinf = {dotclock = 8275232, hdisplay = 0, hsyncstart = 0, hsyncend
= 134, htotal = 0,
  vdisplay = 0, vsyncstart = 0, vsyncend = 30928, vtotal = 633, flags = 0,
privsize = 5319427}
        mode = <value optimized out>
        modecount = <value optimized out>
        dotClock = <value optimized out>
        ver = 2
#3 0x000000000044d6e4 in Dispatch () at ../../dix/dispatch.c:454
        result = <value optimized out>
        client = (ClientPtr) 0x289ea60
        nready = 0
        start_tick = 460
#4 0x00000000004336fd in main (argc=8, argv=0x7fff7e25ba48, envp=<value
optimized out>)
    at ../../dix/main.c:441
        i = 1
        error = 0
        xauthfile = <value optimized out>
        alwaysCheckForInput = {0, 1}


[Original Report]
I'm not sure what should happen when I start an SDL application (like qemu/kvm)
under X, but the X server crashing is definitely the wrong choice.