Created attachment 378970 [details] backtrace of crashed X server Description of problem: I am getting logged out because of X server crashes, typically 2-10 minutes after starting xlockmore. It seems fairly random (and I don't think there's a specific xlock mode that causes it). Xorg.0.log shows no sign at all of the crash (so it's not attached). Attaching gdb to the running X server showed that the crash is due to an assertion failure in the pixman library. A backtrace is attached. (In my opinion, (a) the X server should never allow itself to be killed by an assertion failure, and (b) if it does, it should produce a trace in the log. Something needs to be fixed there.) (Then I typed "gcore" into gdb and that's when the whole system locked solid - not even Alt+SysRq+b would work.) The trace doesn't seem that useful as all the data is optimized out. I've recompiled pixman without optimization and will attach another backtrace if it crashes again. Any pointers as to what to look out for at that time would be welcome. Version-Release number of selected component (if applicable): pixman-0.16.2-1.fc12.x86_64 xorg-x11-server-Xorg-1.7.1-7.fc12.x86_64 How reproducible: It's happened four or so times since I installed F12 ten days ago. Steps to Reproduce: 1. Work on the computer 2. Run "xlock -mode random" and go to lunch 3. Come back to find the login screen instead of the logged in session
Created attachment 379079 [details] Another backtrace with slightly more debugging info I didn't have to wait long. The crash occurs while xlock is doing a "losira" style erase (about line 742 of xlock/erase.c) and seems to result from executing: XCopyArea(dpy,window,window,gc,736,0,0,1132,737,0) It's not documented anywhere that it's illegal to call XCopyArea with a zero width, so either this assertion is wrong or the X server should treat the operation as a no-op before pixman gets involved.
Created attachment 379222 [details] Program that will crash the X server So here's a short C program with just that call in it; I tested it on another F12 box and it killed the X server instantly.
Thanks for the bug report. I believe this is fixed in pixman 0.16.4. Please feel free to reopen if it isn't.
Confirm that the program from comment 2 no longer crashes the X server after updating pixman.