Description:

I'm experiencing some random "Illegal instruction" crashes. It's random because I'm still unable to properly reproduce them, and they vary from one time to another, but sometimes the same context come back. I've been able to generate some coredumps that shows the exact same error occuring for several apps. This includes : gcc (when trying to compile gcc, or sometimes mencoder), rtorrent, mlnet (from mldonkey) and bash. I guess it also affects the kernel because I got many kernel panics, from which I can only get the end of the stack trace displayed on the screen. The things I can see from it vary (from what I remember) : there were page_fault(), other stuff related to tcp, and other things.

For all the coredumps I get (11), the illegal instruction _always_ occurs like it's showed in the attached file (typical_crash). It's within the libc _IO_vfscanf_internal function, called from somewhere I don't know (because I'm unable to compile anything, I can't have the debug symbols). And the insctruction pointer is _IO_vfscanf_internal+304.

Additional info:
Remember I'm unable to compile anything "big" (such as gcc or mencoder) because it always end up somewhere with an Illegal instruction error (either bash or gcc crashing). Smaller programs are OK.

These crashes are not easily reproductibles. For example, I sure it will crash when compiling gcc, but I don't know exacty when. And when I try to reproduce the faulty gcc command after, it just compiles the file without any error.

I've done 7 memtest passes without any error.

When the illegal instruction happens, the insctruction pointer doesn't seems to be aligned with the assembler code. So my guess is that the problem may comes from some glibc alignements mismatchs on x86_64.

All the programs used comes from the binary archlinux packages. Mentionned packages versions:
* core/glibc 2.11.1-1
* community/rtorrent 0.8.6-2
* core/bash 4.1.002-2
* core/gcc 4.4.3-1
* core/gcc-libs 4.4.3-1
* core/kernel26 2.6.32.7-1