Manual: killsnoop-bpfcc

killsnoop(8)					   System Manager's Manual					killsnoop(8)

NAME
       killsnoop - Trace signals issued by the kill() syscall. Uses Linux eBPF/bcc.

SYNOPSIS
       killsnoop [-h] [-x] [-p PID] [-T PID] [-s SIGNAL]

DESCRIPTION
       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 4.4 feature (bpf_perf_event_output()); for kernels older than 4.4, see	 the  version  under
       tools/old, which uses an older mechanism.

       Since this uses BPF, only the root user can use this tool.

REQUIREMENTS
       CONFIG_BPF and bcc.

OPTIONS
       -h     Print usage message.

       -x     Only print failed kill() syscalls.

       -p PID Trace this process ID only which is the sender of signal (filtered in-kernel).

       -T PID Trace this target process ID only which is the receiver of signal (filtered in-kernel).

       -s SIGNAL
	      Trace this signal only (filtered in-kernel).

EXAMPLES
       Trace all kill() syscalls:
	      # killsnoop

       Trace only kill() syscalls that failed:
	      # killsnoop -x

       Trace PID 181 only:
	      # killsnoop -p 181

       Trace target PID 189 only:
	      # killsnoop -T 189

       Trace signal 9 only:
	      # killsnoop -s 9

FIELDS
       TIME   Time of the kill call.

       PID    Source process ID

       COMM   Source process name

       SIG    Signal number. See signal(7).

       TPID   Target process ID

       RES    Result. 0 == success, a negative value (of the error code) for failure.

OVERHEAD
       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 before use.

SOURCE
       This is from bcc.

	      https://github.com/iovisor/bcc

       Also look in the bcc distribution for a companion _examples.txt file containing example usage, output, and commentary
       for this tool.

OS
       Linux

STABILITY
       Unstable - in development.

AUTHOR
       Brendan Gregg

SEE ALSO
       opensnoop(8), funccount(8)

USER COMMANDS						 2015-08-20						killsnoop(8)