Hello all,
I hope somebody can give me some tips on how to attack the following problem: I have developed a userspace application running on a 2.4.31 mips embedded system. This app consequently runs for a a few days and then 'stops' after 5 days, 17 hours and a few minutes. By 'stops', I mean that it is still running, but does no longer do it's job (does not answer on sockets, for example), and that strace shows no system call activity :
# strace -p 81 Process 81 attached - interrupt to quit (nothing is printed after this line)
/proc/state, however, reports the process is in sleeping state
# cat /proc/81/stat 81 (main) S 1 10 10 0 -1 256 541 (...)
which is what I would expect, since the cpu load is near 0.00.
I included sysreq support in the kernel, and a sysrq-t gives the follolowing output for this process. (I added symbol names myself)
Call Trace: [] [] [] []
This callstack confuses me: is the process stuck while performing a gettimeofday ?
So, my question is: how can I find out what this process is doing at this moment ? The obvious answer would be to attach gdb, but for some reason beyond my understanding it seems that gdb or some part of the toolchain is broken in some way, since gdb only reports a corrupted stack and is not able to provide a call trace. If nothing else works I shall try to upgrade my toolchain, but I'd like to investigate more simple options first.
Please let me know if I need to provide any more information.
Thank you very much for any tips.
mips-linux-gcc (GCC) 3.3.6 GNU ld version 2.14.90.0.8 20040114 Linux (none) 2.4.31-INCAIP-4.3 #2 Mon Mar 19 11:13:58 CET 2007 mips unknown