On Fri, 14 Mar 2003, Scott Gilbertson wrote:
> The attached small C program causes my Xfbdev server to crash in CopyGC.
> Usually it's a SIGSEGV, but sometimes its a SIGILL. When the program
> starts, it shows a blank screen. Click mouse button 1 and it starts
> animating some circles, and does so until you kill it (control-C or
> whatever). On my embedded system, it crashes the X server in about 10
> minutes. Using gdb, I've looked at the source and destination GC, including
> all the function pointers. Everything looks fine -- no indication of what
> made it crash.
>
> Running the same program on a desktop PC, it hasn't crashed yet, although I
> haven't tried to run it for all that long.
>
> I'm wondering:
> a) Is there any obvious should-not-do code in the attached program?
Even a malicious app should not be able to crash the server.
> b) Is high-volume XCreateGC/XCopyGC/XFreeGC (see below) considered normal?
I'm sure there are other apps that do things like that. I think
nearly every abuse has been done at one point or another.
> c) Could the high volume be causing the problem?
I still think it's likely to be a system memory problem or code generation
problem.
> d) Can anyone else replicate this crash?
If I can remember I'll leave it running overnight on one of my machines
tonight.
Mark.
>
> My Xfbdev is version 4.3, but the same thing happens on 4.2.0. I've tried
> compiling it with gcc 3.2.1 and 3.3 (not released yet), and both with and
> without optimization. The one I'm running at the moment was compiled for
> Intel 486.
>
> My system is an Arcom SBC-GX1, which uses a National Geode GX1 chip
> (Pentium-compatible). It has 128 megs of RAM and no swap. At no time
> during the test does the free RAM drop below 20 megs. It's obviously
> conceivable that the problem is related to the non-Intel processor, but I
> would have expected the symptoms to change with different optimizer settings
> if that were the case. I suppose the kernel or video FB driver could also
> be at fault.
>
> My linux is:
> Linux version 2.4.18-rthal5 ([EMAIL PROTECTED]) (gcc version 3.2.1) #1 Wed
> Dec 18 17:39:47 EST 2002
>
> History:
> I've been trying to track down an Xfbdev crash when running a gcj-compiled
> (Java) executable using the xlib peers. I noticed that the C xlib examples
> I found don't do very many XCreateGC, XCopyGC and XFreeGC calls, whereas the
> java library peers create a new GC for every repaint. The attached C
> program creates a new GC every paint, just like the peers. Since it crashes
> the server in the same manner as the Java program, it's not strictly a
> problem with the Java compiler or libraries.
>
>
>
_______________________________________________
XFree86 mailing list
[EMAIL PROTECTED]
http://XFree86.Org/mailman/listinfo/xfree86
