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Subject[RFC] perf probe: -x option position issue
hi,
Martin found out following issue.. having following ex binary:

---
int main(void)
{
return 0;
}
---

following will create uprobe on main:

[root@dell-per510-01 perf]# gcc -g -o ex ex.c
[root@dell-per510-01 perf]# ./perf probe -x ./ex -a main
Added new event:
probe_ex:main (on main in /root/linux/tools/perf/ex)

You can now use it in all perf tools, such as:

perf record -e probe_ex:main -aR sleep 1

[root@dell-per510-01 perf]# cat /sys/kernel/debug/tracing/uprobe_events
p:probe_ex/main /root/linux/tools/perf/ex:0x00000000000004f6


while following will create (?) kprobe with complain in dmesg:

[root@dell-per510-01 perf]# gcc -g -o ex ex.c
[root@dell-per510-01 perf]# ./perf probe -a main -x ./ex
Added new event:
probe:main (on main in ex)

You can now use it in all perf tools, such as:

perf record -e probe:main -aR sleep 1

[root@dell-per510-01 perf]# dmesg | tail -2
[16986.182159] Could not insert probe at ex:main+0: -2
[16986.187030] This probe might be able to register aftertarget module is loaded. Continue.


that does not seem as an expected behaviour, or am I missing something?

thanks,
jirka


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