I've rebuilt xorg-server with nostrip nocheck noopt and added a load of debug, with that the backtrace shows
Program received signal SIGSEGV, Segmentation fault. 0x00000020 in ?? () (gdb) where #0 0x00000020 in ?? () #1 0x2a09b5f0 in xf86SIGIO (sig=707031856) at ../../../../../hw/xfree86/os-support/linux/../shared/sigio.c:121 Backtrace stopped: previous frame inner to this frame (corrupt stack?) (gdb) q which seems to make sense, because it's happening as I touch and the sigio seems to be bubbling touch events through evdev. I've added a load of debug and it does seem to be getting to the end of the sigio routine, just not returning properly (that line 121 is the resteration of the errno); I've also added loads of debug to Evdev, again it seems to be going through the motions ok. here is my (rather cryptic) debug I've added for the last of the events that happened before it died. xf86SIGIO for 29 xf86SIGIO found i=0 r=1 func=0x2a078999 xf86SigioReadInput: closure=0x2a26a5f0 read_info=0x40526629 EvdevReadInput: pInfo=0x2a26a5f0 EvdevReadInput: pInfo=0x2a26a5f0 looptop EvdevReadInput: post read len=32 (bufsize=256) EvdevReadInput: <process 0 EvdevProcessEvent: Abs EvPAbsME: value=454 EvPAbsME: (2) value=454 EvPAbsME: (3) value=454 EvPAbsME: (5) value=454 EvdevReadInput: >process 0 EvdevReadInput: <process 1 EvdevProcessEvent: Sync EvPSyncE pEvdev=0x2a31b4b0 vals=0x2a31cec0 EvPSyncE (2) ArrayLength=32 EvPSyncE (3) pEvdev=0x2a31b4b0 vals=0x2a31cec0 EvdevReadInput: >process 1 xf86SIGIO exit for 29 Program received signal SIGSEGV, Segmentation fault. 0x00000020 in ?? () (gdb) where #0 0x00000020 in ?? () #1 0x2a09b5f0 in xf86SIGIO (sig=707031856) at ../../../../../hw/xfree86/os-support/linux/../shared/sigio.c:121 Backtrace stopped: previous frame inner to this frame (corrupt stack?) (gdb) q Given that's in a signal handler perhaps the rest of the stack is fine; it's just the return data that's had it. -- -----Open up your eyes, open up your mind, open up your code ------- / Dr. David Alan Gilbert | Running GNU/Linux | Happy \ \ gro.gilbert @ treblig.org | | In Hex / \ _________________________|_____ http://www.treblig.org |_______/ -- To UNSUBSCRIBE, email to debian-x-requ...@lists.debian.org with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org Archive: http://lists.debian.org/20130719010937.GA25902@gallifrey