#910846 X server "Segmentation fault at address 0x0" when using about:support in Firefox-based browsers.

Package:
xserver-xorg-video-radeon
Source:
xserver-xorg-video-ati
Description:
X.Org X server -- AMD/ATI Radeon display driver
Submitter:
Date:
2021-01-20 11:18:04 UTC
Severity:
normal
#910846#5
Date:
2018-10-12 04:40:36 UTC
From:
To:
I am using a standalone AMD HD 7670. "firmware-amd-graphics" is installed and loaded during boot.
It seems that whenever I tries to query information about hardware acceleration, X segfaults.
"dmesg" does not show any error or warning after segfault.
Sometimes other programs or games trigger it as well, with the same problem described in the file Xorg.0.log.
#910846#10
Date:
2018-10-12 08:10:27 UTC
From:
To:
[...]

Please make sure the xserver-xorg-video-radeon-dbgsym and
xserver-xorg-core-dbgsym packages are installed, and either get a
backtrace with gdb or another log file.


Does the problem also happen without Option "AccelMethod" "EXA"? That's
the default and recommended configuration for your GPU.
#910846#15
Date:
2018-10-14 04:53:21 UTC
From:
To:
There is no "xserver-xorg-video-radeon-dbgsym" or "xserver-xorg-core-dbgsym" in the repo.
#910846#20
Date:
2018-10-15 09:43:58 UTC
From:
To:
They're in a separate repository:

deb	https://deb.debian.org/debian-debug/	<suite>-debug	main contrib non-free

Replace <suite> with the name of the suite you're using in your main
repository entry.
#910846#25
Date:
2018-10-15 11:35:46 UTC
From:
To:
Here is the output of GDB.
I am no developer, thus I do not know whether this is what you want.
#910846#30
Date:
2018-10-15 11:43:46 UTC
From:
To:
Sorry, I have found the problem. If I remove this line from "/etc/X11/xorg.conf", X would not crash:
Option "DRI" "3"
So it is my fault. Sorry.
#910846#35
Date:
2018-10-15 15:16:12 UTC
From:
To:
If removing

	Option "AccelMethod" "EXA"

as well also works, that would be the best solution for you.

The crash is still a bug, even though EXA & DRI3 isn't recommended,
because it can't work correctly in some cases.

Any chance you can test if the attached patch fixes the crash?
#910846#40
Date:
2018-10-15 15:48:21 UTC
From:
To:
Using "glamor" instead of "EXA" works. However, the manpage says "EXA (for pre-TAHITI GPUs) and glamor (for R300 or higher)". TURKS GPUs are pre-TAHITI ones.
I cannot test the patch for you. I have said, I am no developer, and I do not want to mess up my OS by recompiling an important package.
#910846#45
Date:
2018-10-15 16:55:46 UTC
From:
To:
They're also post-R300. :) The next sentence (with side note which
doesn't apply here elided) in the manpage is:

The default is glamor with R600 or newer [...], otherwise EXA.
No problem. I'll send out the patch for review anyway, it's pretty
likely it'll fix the crash.