NAME

execsnoop - Trace new processes via exec() syscalls. Uses Linux eBPF/bcc.

SYNOPSIS

execsnoop [-h] [-T] [-t] [-x] [--cgroupmap CGROUPMAP] [--mntnsmap MAPPATH] [-u USER] [-q] [-n NAME] [-l LINE] [-U] [--max-args MAX_ARGS]

DESCRIPTION

execsnoop traces new processes, showing the filename executed and argument list.

It works by traces the execve() system call (commonly used exec() variant). This catches new processes that follow the fork->exec sequence, as well as processes that re-exec() themselves. Some applications fork() but do not exec(), eg, for worker processes, which won't be included in the execsnoop output.

This works by tracing the kernel sys_execve() function using dynamic tracing, and will need updating to match any changes to this function.

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

REQUIREMENTS

CONFIG_BPF and bcc.

OPTIONS

-h: Print usage message.
-T: Include a time column (HH:MM:SS).
-U: Include UID column.
-t: Include a timestamp column.
-u USER: Filter by UID (or username)
-x: Include failed exec()s
-q: Add "quotemarks" around arguments. Escape quotemarks in arguments with a backslash. For tracing empty arguments or arguments that contain whitespace.
-n NAME: Only print command lines matching this name (regex)
-l LINE: Only print commands where arg contains this line (regex)
--max-args MAXARGS: Maximum number of arguments parsed and displayed, defaults to 20
--cgroupmap MAPPATH: Trace cgroups in this BPF map only (filtered in-kernel).
--mntnsmap MAPPATH: Trace mount namespaces in this BPF map only (filtered in-kernel).
-P PPID: Trace this parent PID only.

EXAMPLES

Trace all exec() syscalls:: # execsnoop
Trace all exec() syscalls, and include timestamps:: # execsnoop -t
Display process UID:: # execsnoop -U
Trace only UID 1000:: # execsnoop -u 1000
Trace only processes launched by root and display UID column:: # execsnoop -Uu root
Include failed exec()s:: # execsnoop -x
Put quotemarks around arguments.: # execsnoop -q
Only trace exec()s where the filename contains "mount":: # execsnoop -n mount
Only trace exec()s where argument's line contains "testpkg":: # execsnoop -l testpkg
Trace a set of cgroups only (see special_filtering.md from bcc sources for more details):: # execsnoop --cgroupmap /sys/fs/bpf/test01

FIELDS

TIME: Time of exec() return, in HH:MM:SS format.
TIME(s): Time of exec() return, in seconds.
UID: User ID
PCOMM: Parent process/command name.
PID: Process ID
PPID: Parent process ID
RET: Return value of exec(). 0 == successs. Failures are only shown when using the -x option.
ARGS: Filename for the exec(), followed be up to 19 arguments. An ellipsis "..." is shown if the argument list is known to be truncated.

OVERHEAD

This traces the kernel execve function and prints output for each event. As the rate of this is generally expected to be low (< 1000/s), the overhead is also expected to be negligible. If you have an application that is calling a high rate of exec()s, 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, Rocky Xing