killsnoop - Trace signals issued by the kill() syscall. Uses Linux eBPF/bcc.
killsnoop [-h] [-x] [-p PID]
killsnoop traces the kill() syscall, to show signals sent via this method. This
may be useful to troubleshoot failing applications, where an unknown mechanism
is sending signals.
This works by tracing the kernel sys_kill() function using dynamic tracing, and
will need updating to match any changes to this function.
This makes use of a Linux 4.5 feature (bpf_perf_event_output()); for kernels
older than 4.5, see the version under tools/old, which uses an older
Since this uses BPF, only the root user can use this tool.
CONFIG_BPF and bcc.
- Print usage message.
- Only print failed kill() syscalls.
- -p PID
- Trace this process ID only (filtered in-kernel).
- Trace all kill() syscalls:
- # killsnoop
- Trace only kill() syscalls that failed:
- # killsnoop -x
- Trace PID 181 only:
- # killsnoop -p 181
- Time of the kill call.
- Source process ID
- Source process name
- Signal number. See signal(7).
- Target process ID
- Result. 0 == success, a negative value (of the error code)
This traces the kernel kill function and prints output for each event. As the
rate of this is generally expected to be low (< 100/s), the overhead is
also expected to be negligible. If you have an application that is calling a
very high rate of kill()s for some reason, then test and understand overhead
This is from bcc.
Also look in the bcc distribution for a companion _examples.txt file containing
example usage, output, and commentary for this tool.
Unstable - in development.