Skip to content

Latest commit

 

History

History
79 lines (69 loc) · 2.61 KB

README.md

File metadata and controls

79 lines (69 loc) · 2.61 KB
Raw

Useful SystemTap scripts for daily tasks

This repo holds some SystemTap scripts, which I have used on my job on a more or less daily basis.

filewatch.stp

Used for watching file accesses from Kernel space. Useful if you want to know which user/program accesses a file.

Example:

[root@devel-el6 ~]# stap filewatch.stap /etc/passwd
PROG(PID)            UID     FILE/FLAGS
crond(1118)          0       "/etc/passwd", O_RDONLY|O_CLOEXEC
crond(1118)          0       "/etc/passwd", O_RDONLY|O_CLOEXEC
crond(1118)          0       "/etc/passwd", O_RDONLY|O_CLOEXEC
crond(1118)          0       "/etc/passwd", O_RDONLY|O_CLOEXEC
whoami(1693)         500     "/etc/passwd", O_RDONLY|O_CLOEXEC
getent(1695)         500     "/etc/passwd", O_RDONLY|O_CLOEXEC

malloc.stap

Used for generating memory allocation stacktraces, which then could be transformed into a flamegraph with the magnificent toolchain from Brendan Gregg, which resides here.

Example:

[root@devel-el6 ~]# stap -d /lib64/ld-2.12.so -d /lib64/libc-2.12.so -d /home/devel/memeater malloc.stap memeater
sys_mmap+0x0 [kernel]
tracesys+0xd9 [kernel]
mmap64+0xa [ld-2.12.so]
__libc_memalign+0x81 [ld-2.12.so]
_dl_init_paths+0x8b [ld-2.12.so]
dl_main+0xb5a [ld-2.12.so]
_dl_sysdep_start+0x18e [ld-2.12.so]
_dl_start+0x374 [ld-2.12.so]
0x7ff7137c9b08 [ld-2.12.so+0xb08]
4096

sys_mmap+0x0 [kernel]
tracesys+0xd9 [kernel]
mmap64+0xa [libc-2.12.so]
_int_malloc+0x1265 [libc-2.12.so]
malloc+0x71 [libc-2.12.so]
memeat+0x5a [memeater]
main+0x11f [memeater]
__libc_start_main+0xfd [libc-2.12.so]
_start+0x29 [memeater]
104898560

sys_mmap+0x0 [kernel]
tracesys+0xd9 [kernel]
mmap64+0xa [libc-2.12.so]
_IO_file_doallocate+0x7c [libc-2.12.so]
_IO_doallocbuf+0x2c [libc-2.12.so]
_IO_file_overflow@@GLIBC_2.2.5+0x190 [libc-2.12.so]
_IO_file_xsputn@@GLIBC_2.2.5+0x6d [libc-2.12.so]
_IO_vfprintf+0x159 [libc-2.12.so]
printf+0x9a [libc-2.12.so]
main+0x16c [memeater]
__libc_start_main+0xfd [libc-2.12.so]
_start+0x29 [memeater]
4096

sys_mmap+0x0 [kernel]
tracesys+0xd9 [kernel]
mmap64+0xa [libc-2.12.so]
_IO_file_doallocate+0x7c [libc-2.12.so]
_IO_doallocbuf+0x2c [libc-2.12.so]
_IO_file_underflow@@GLIBC_2.2.5+0x1b4 [libc-2.12.so]
_IO_default_uflow+0xe [libc-2.12.so]
getchar+0xbc [libc-2.12.so]
main+0x171 [memeater]
__libc_start_main+0xfd [libc-2.12.so]
_start+0x29 [memeater]
4096