On Mar 17, 11 11:39:07 +0100, Guido Berhoerster wrote:
when using the intellegacy driver the xserver segfaults shortly after being started by gdm. In order to get a backtrace I've moved the Xorg binary and replaced it with a wrapper that calls it through gdb as outlined in http://wiki.x.org/wiki/Development/Documentation/ServerDebugging#Version1. This apparently starts the xserver (as I can see from the logfile) but then gets stuck with a black screen. The same happens when starting it through startx rather than gdm and attaching to the xserver after starting it is not an option since it only lives for a second or so. What's wrong here, how can I get a backtrace?
Apparently, your Xserver doesn't crash directly after startup, but
rather when gdm wants to actually draw something on it.
That is bad, because starting Xserver by a script that runs it via gdb
interrupts the signal flow that is used to signal gdm that the Xserver
is ready to receive commands.
There is no easy way to do this with a single machine. If you can
connect remotely, you can do everything as before, and when you have the
black screen, find the gdm process and send it a SIGUSR1. That should
trigger rendering, and probably the Xserver crash, this time getting you
a backtrace.
You see, this is highly advanced debugging :-(((
Good luck
Matthias
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Matthias Hopf