2012-11-02 09:26:01

by Jovi Zhang

[permalink] [raw]
Subject: [BUG] arm: perf probe can not get __copy_to_user callchain symbol

Hi

In ARM, It seems that we cannot get __copy_to_user callchain symbol,
like below output,

I guess it due to function __copy_to_user don't compile with unwind
info, is this right?(not sure)

If the problem is relate with unwind info, is there anybody can make a
patch on this? I'm not familiar with unwind stuff very much.
thanks very much.


#perf record -e probe:__copy_to_user* -g -a ls

# Events: 677 probe:__copy_to_user
#
# Overhead Command Shared Object Symbol
# ........ ....... ................. ..............
#
93.50% perf [kernel.kallsyms] [k] __copy_to_user
|
--- __copy_to_user
|
|--29.38%-- 0xffffffff
| 0xc0b00604
|
|--21.80%-- (nil)
| |
| |--92.03%-- 0xc0b00604
| |
| |--5.07%-- 0xc0af1bcc
| |
| |--1.45%-- 0xc0ab83b4
| |
| |--0.72%-- 0xc0af5a20
| |
| --0.72%-- 0xc0b0c8b0
|
|--19.91%-- 0xc0b0c8b0
|
|--19.91%-- 0xc0af5a20
|
|--8.53%-- 0xc0b0c658
--0.47%-- [...]