Bug#911680: xserver-xorg-core: X server crashes when loading libglamorgl.so module (Bug #911680)

[Bernhard Übelacker]

Hello Massimo Manghi,
just tried to reproduce the issue inside a debian buster amd64 qemu VM.
I never hit the crash and found you were probably running inside a VirtualBox.

Nevertheless with installed debug informations I think the crash shown
in the Xorg.log points to that location:


(gdb) bt
#0 glamor_egl_init (scrn=***@entry=0x5555557fc0f0, fd=<optimized out>) at ../../../../../../glamor/glamor_egl.c:992
#1 0x00007ffff5088172 in try_enable_glamor (pScrn=0x5555557fc0f0) at ../../../../../../../hw/xfree86/drivers/modesetting/driver.c:767
#2 PreInit (pScrn=0x5555557fc0f0, flags=<optimized out>) at ../../../../../../../hw/xfree86/drivers/modesetting/driver.c:994
#3 0x00005555555ef6c0 in InitOutput (pScreenInfo=***@entry=0x5555557c3780 <screenInfo>, argc=***@entry=1, argv=***@entry=0x7fffffffed08) at ../../../../../../hw/xfree86/common/xf86Init.c:522
#4 0x00005555555b26df in dix_main (argc=1, argv=0x7fffffffed08, envp=<optimized out>) at ../../../../dix/main.c:193
#5 0x00007ffff64cbb17 in __libc_start_main (main=0x55555559c640 <main>, argc=1, argv=0x7fffffffed08, init=<optimized out>, fini=<optimized out>, rtld_fini=<optimized out>, stack_end=0x7fffffffecf8) at ../csu/libc-start.c:310
#6 0x000055555559c67a in _start ()


glamor/glamor_egl.c:
990
991 renderer = glGetString(GL_RENDERER);
992 if (strstr((const char *)renderer, "llvmpipe")) {
993 xf86DrvMsg(scrn->scrnIndex, X_INFO,
994 "Refusing to try glamor on llvmpipe\n");


Therefore my guess would be that "glGetString(GL_RENDERER)" returns
in VirtualBox (or at least that installation) something odd.


That line originates from this patch that is applied upstream and
I assume is cherry picked [1] for that debian package version:
./debian/patches/08_dont-init-glamor-on-llvmpipe.diff

Upstream added on top of that another patch [2] to
avoid a crash that is probably exact that one we see here.

Kind regards,
Bernhard

[1] https://cgit.freedesktop.org/xorg/xserver/commit/glamor/?id=0a9415cf
[2] https://cgit.freedesktop.org/xorg/xserver/commit/glamor/glamor_egl.c?id=af151895f3cb1755a7a5631f2398a3d3b219cbef

[Massimo MANGHI]

Hello Bernhard

thank you for taking care of the problem so quickly

Post by Bernhard Übelacker
Hello Massimo Manghi,
just tried to reproduce the issue inside a debian buster amd64 qemu VM.
I never hit the crash and found you were probably running inside a VirtualBox.

you got it

Post by Bernhard Übelacker
Nevertheless with installed debug informations I think the crash shown
[...]
990
991 renderer = glGetString(GL_RENDERER);
992 if (strstr((const char *)renderer, "llvmpipe")) {
993 xf86DrvMsg(scrn->scrnIndex, X_INFO,
994 "Refusing to try glamor on llvmpipe\n");
Therefore my guess would be that "glGetString(GL_RENDERER)" returns
in VirtualBox (or at least that installation) something odd.
That line originates from this patch that is applied upstream and
./debian/patches/08_dont-init-glamor-on-llvmpipe.diff
Upstream added on top of that another patch [2] to
avoid a crash that is probably exact that one we see here.

very good, I guess this clarifies the issue and the new patch will be
included in the next upload, is it correct? Am I supposed to take any
further action? Something like changing the bug status or applying some
extra tag to the bug in order to specify the environment (VirtualBox)
where the problem occurs?

thank you a

[Bernhard Übelacker]

Hello Massimo,

... and the new patch will be
included in the next upload, is it correct? Am I supposed to take any
further action? Something like changing the bug status or applying some
extra tag to the bug in order to specify the environment (VirtualBox)
where the problem occurs?

I really was just trying to debug the issue,
further actions are up to the maintainers.

Also another user reported a workaround in [1] that
you might have not received by mail.

Kind regards,
Bernhard

[1] https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=911680#18

[Debian Bug Tracking System]

Your message dated Thu, 25 Oct 2018 09:01:05 +0000
with message-id <E1gFbVp-0003xj-***@fasolo.debian.org>
and subject line Bug#911680: fixed in xorg-server 2:1.20.2-1
has caused the Debian Bug report #911680,
regarding xserver-xorg-core: X server crashes when loading libglamorgl.so module
to be marked as done.

This means that you claim that the problem has been dealt with.
If this is not the case it is now your responsibility to reopen the
Bug report if necessary, and/or fix the problem forthwith.

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