On Wed, 2006-10-11 at 02:32 +0200, Frans Pop wrote:
>
> On Monday 02 October 2006 13:51, Frans Pop wrote:
> > After playing a particular game (Chromium) in full screen mode, the
> > XOrg server crashes about 2 out of 3 times when switching back to KDE.
>
> With the help of David I've done some further research on this and
> obtained a full backtrace from gdb with both the xserver and the i810
> driver compiled with debugging symbols (attached).
>
> I used the upstream 1.7.0 version of the i810 driver for this, so it is
> confirmed that the new driver does _not_ fix this issue.
>
> From the Xorg log:
> (II) Module i810: vendor="X.Org Foundation"
> compiled for 7.1.1, module version = 1.7.0
> Module class: X.Org Video Driver
> ABI class: X.Org Video Driver, version 1.0
>
> My default screen resolution when running KDE is 1280x1024. The game
> switches that to fullscreen mode at 800x600.
> The crash mostly happens when exiting the game, but also sometimes when
> starting it.
> Both starting and exiting the game are also sometimes successful.
Thanks for the detailed information. This looks like a race condition
between the mode switching code leaving pScrn->currentMode NULL for some
time and I830SetCursorPosition() dereferencing it unconditionally,
getting called from the SIGIO handler.
Can you try the attached patch? Alternatively, possible workarounds are:
* Disabling SilkenMouse
* Not moving the mouse while the mode is being switched ;)
Alan, if the patch works for Frans, should I push it to xf86-video-intel
git, or would you like to fix this differently?
> Program received signal SIGSEGV, Segmentation fault.
> [Switching to Thread 47953045281504 (LWP 8640)]
> I830SetCursorPosition (pScrn=0x6ea2d0, x=33, y=61)
> at ../../src/i830_cursor.c:524
> 524 if (x >= pScrn->currentMode->HDisplay) x =
> pScrn->currentMode->HDisplay - 1;
> (gdb) bt f
> #0 I830SetCursorPosition (pScrn=0x6ea2d0, x=33, y=61)
> at ../../src/i830_cursor.c:524
> #1 0x00002b9cf1921c39 in xf86SetCursor ()
> from /usr/lib/xorg/modules/libramdac.so
> #2 0x00002b9cf19213c9 in xf86CursorSetCursor ()
> from /usr/lib/xorg/modules/libramdac.so
> #3 0x00000000004cacf2 in miPointerMove (pScreen=0x6f0cc0, x=34, y=62,
> time=884799019)
> at ../../mi/mipointer.c:487
> #4 0x00000000004cadce in miPointerAbsoluteCursor (x=34, y=62,
> time=884799019)
> at ../../mi/mipointer.c:456
> #5 0x000000000049e170 in xf86PostMotionEvent (device=0x748c80,
> is_absolute=0,
> first_valuator=<value optimized out>, num_valuators=2)
> at ../../../../hw/xfree86/common/xf86Xinput.c:1057
> #6 0x00002b9cf139d76c in xf86MouseProtocolNameToID ()
> from /usr/lib/xorg/modules/input/mouse_drv.so
> #7 0x00002b9cf139dce8 in xf86MouseProtocolNameToID ()
> from /usr/lib/xorg/modules/input/mouse_drv.so
> #8 0x00002b9cf139e182 in xf86MouseProtocolNameToID ()
> from /usr/lib/xorg/modules/input/mouse_drv.so
> #9 0x00000000004803bf in xf86SigioReadInput (fd=<value optimized
> out>, closure=0x7479d0)
> at ../../../../hw/xfree86/common/xf86Events.c:1232
> #10 0x000000000046d60f in xf86SIGIO (sig=<value optimized out>)
>
> at ../../../../../hw/xfree86/os-support/linux/../shared/sigio.c:125
> #11 0x00002b9cf0027110 in killpg () from /lib/libc.so.6
> #12 0x0000000000000000 in ?? ()
--
Earthling Michel Dänzer | http://tungstengraphics.com
Libre software enthusiast | Debian, X and DRI developer
diff --git a/src/i830_cursor.c b/src/i830_cursor.c
index c5c904c..8343b6b 100644
--- a/src/i830_cursor.c
+++ b/src/i830_cursor.c
@@ -520,11 +520,17 @@ #endif
x -= pScrn->frameX0;
y -= pScrn->frameY0;
- /* Clamp the cursor position to the visible screen area */
- if (x >= pScrn->currentMode->HDisplay) x = pScrn->currentMode->HDisplay - 1;
- if (y >= pScrn->currentMode->VDisplay) y = pScrn->currentMode->VDisplay - 1;
- if (x <= -I810_CURSOR_X) x = -I810_CURSOR_X + 1;
- if (y <= -I810_CURSOR_Y) y = -I810_CURSOR_Y + 1;
+ if (pScrn->currentMode) {
+ /* Clamp the cursor position to the visible screen area */
+ if (x >= pScrn->currentMode->HDisplay) x = pScrn->currentMode->HDisplay - 1;
+ if (y >= pScrn->currentMode->VDisplay) y = pScrn->currentMode->VDisplay - 1;
+ if (x <= -I810_CURSOR_X) x = -I810_CURSOR_X + 1;
+ if (y <= -I810_CURSOR_Y) y = -I810_CURSOR_Y + 1;
+ } else {
+ /* Can't ensure the cursor will be visible, so hide it */
+ hide = TRUE;
+ show = FALSE;
+ }
#if 0
/*
