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Calloc is called from some signal handler in my production code. I know that it is not safe to call calloc from a signal handler. I need to find the point where is this done in my production code, but backtrace is of no help. Please guide

print $_siginfo.si_signo

I know above tells the signal number of the current signal. But that does not help me to find the point.

Following is the call stack, the stacktrace just below calloc is of no use.

#26 0x00002aaaaaccfec9 in calloc () from 
#27 0x00000000047c522f in Ox4074f61149c39b9f ()
#28 0x00000000047aa93a in Ox4074ff7b773cfdf6 ()
#29 0x000000000468c981 in Ox4074ea3d1f5df78f ()
#30 0x000000000468e667 in ?? ()
#31 0x000000000468f2dd in ?? ()
#32 0x0000000004686f2c in Ox4074ea18721a0b5d ()
#33 0x00000000047b3727 in Ox4075027a04de15e3 ()
#34 0x00000000047efdd4 in ?? ()
#35 <signal handler called>
#36 0x00002aaabc5d0332 in __lll_lock_wait () from /lib64/libpthread.so.0
#37 0x00002aaabc5cb5d8 in _L_lock_854 () from /lib64/libpthread.so.0
#38 0x00002aaabc5cb4a7 in pthread_mutex_lock () from 
    /lib64/libpthread.so.0
ks1322
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Rock
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  • I see from siginfo structure that SIGSTOP signal is generated. As far as I understad SIGSTOP can't be handled. Then who calls calloc from signal handler?? – Rock Feb 16 '19 at 07:29

1 Answers1

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Please guide

The most likely explanation for the stack trace you observed: you are analyzing a core dump from production machine on a different machine, and using the wrong system libraries to do so.

See this answer on how to do this properly.

Employed Russian
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  • NO, the stack trace is generated on the same machine on which the process is running. – Rock Feb 04 '19 at 04:36
  • @Rock I don't believe this stack trace. Perhaps you've updated system `libc` between starting the production server that crashed and the time you've collected the stack trace? – Employed Russian Feb 04 '19 at 05:51
  • I got the same call stack during my local executable run as well, can anyone guide? – Rock Feb 18 '19 at 12:31