Process terminated by signal 6, core shows kind of loop in libc

Question

Hi

On analysis of the core of a process (terminated by signal 6), on LINUX, stack bt shows :

Core was generated by `/opt/namsam/pac_rrc_qx_e1/bin/rrcprb'.

Program terminated with signal 6, Aborted.

#0  0x0000005555ffb004 in epoll_wait () from /lib64/libc.so.6

(gdb) bt

#0  0x0000005555ffb004 in epoll_wait () from /lib64/libc.so.6
#1  0x0000005555ffafe8 in __epoll_wait_nocancel () from /lib64/libc.so.6
#2  0x0000005555ffafe8 in __epoll_wait_nocancel () from /lib64/libc.so.6
#3  0x0000005555ffafe8 in __epoll_wait_nocancel () from /lib64/libc.so.6
#4  0x0000005555ffafe8 in __epoll_wait_nocancel () from /lib64/libc.so.6
#5  0x0000005555ffafe8 in __epoll_wait_nocancel () from /lib64/libc.so.6
#6  0x0000005555ffafe8 in __epoll_wait_nocancel () from /lib64/libc.so.6
#7  0x0000005555ffafe8 in __epoll_wait_nocancel () from /lib64/libc.so.6

libc seems to have gone in some loop.. Did something go wrong with the application "rrcprb" here..? please help me debug this issue..?

Answer 1

Since __epoll_wait_nocancel does not call itself, it's pretty clear that the stack trace you've got is bogus. Most likely cause is incorrect unwind descriptors in your libc.so.6.

It's also somewhat unlikely that you actually crashed in epoll_wait. Try thread apply all where, and see if there is a "more interesting" stack trace / thread for you to look at.