How to track the functions in self-written module using SystemTap?

[David Smith]

On 11/17/2015 09:38 PM, Nan Xiao wrote:
> Hi David,
> 
> Yes, the "FULL_PATH_TO_KEX" works:
> 
> ~/Downloads/kernel/105.ops # stap -l
> 'module("/root/Downloads/kernel/105.ops/kex.ko").function("*")'
> module("/root/Downloads/kernel/105.ops/kex.ko").function("_open@/root/Downloads/kernel/105.ops/kex.c:21")
> module("/root/Downloads/kernel/105.ops/kex.ko").function("_read@/root/Downloads/kernel/105.ops/kex.c:45")
> module("/root/Downloads/kernel/105.ops/kex.ko").function("_release@/root/Downloads/kernel/105.ops/kex.c:33")
> module("/root/Downloads/kernel/105.ops/kex.ko").function("copy_to_user@/usr/src/linux-3.12.49-3/arch/x86/include/asm/uaccess_64.h:72")
> module("/root/Downloads/kernel/105.ops/kex.ko").function("kex_cleanup@/root/Downloads/kernel/105.ops/kex.c:90")
> module("/root/Downloads/kernel/105.ops/kex.ko").function("kex_init@/root/Downloads/kernel/105.ops/kex.c:61")
> 
> But the "RELATIVE_PATH_TO_KEX" doesn't work:
> ~/Downloads/kernel/105.ops # stap -l 'module("./kex.ko").function("*")'
> ~/Downloads/kernel/105.ops #
> 
> Is it the expected behavior of SystemTap? Thanks!

Good question. You are correct, using relative paths doesn't seem to
work. I've filed PR19265 on this issue.

<https://sourceware.org/bugzilla/show_bug.cgi?id=19265>

Feel free to add yourself to the CC list on that bug. If you have the
time, also feel free to look into this more.

-- 
David Smith
dsmith@redhat.com
Red Hat
http://www.redhat.com
256.217.0141 (direct)
256.837.0057 (fax)