Re: Re: [PATCH UPDATED 3/3] tracing: Provide trace events interfacefor uprobes

From: Masami Hiramatsu
Date: Thu Apr 12 2012 - 22:29:16 EST


(2012/04/12 23:49), Srikar Dronamraju wrote:
>>> +
>>> + # echo 'p /bin/zsh:0x46420 %ip %ax' > uprobe_events
>>> +
>>> +Please note: User has to explicitly calculate the offset of the probepoint
>>> +in the object. We can see the events that are registered by looking at the
>>> +uprobe_events file.
>>> +
>>> + # cat uprobe_events
>>> + p:uprobes/p_zsh_0x46420 /bin/zsh:0x0000000000046420
>>
>> Doesn't uprobe_events show the arguments of existing events?
>> And also, could you add an event format of above event here?
>>
>
> [root@f14kvm tracing]# cat uprobe_events
> [root@f14kvm tracing]# echo 'p /bin/zsh:0x46420 %ip %ax' > uprobe_events
> [root@f14kvm tracing]# cat uprobe_events
> p:uprobes/p_zsh_0x46420 /bin/zsh:0x00046420 arg1=%ip arg2=%ax
> [root@f14kvm tracing]# cat events/uprobes/p_zsh_0x46420/format
> name: p_zsh_0x46420
> ID: 922
> format:
> field:unsigned short common_type; offset:0; size:2; signed:0;
> field:unsigned char common_flags; offset:2; size:1; signed:0;
> field:unsigned char common_preempt_count; offset:3; size:1; signed:0;
> field:int common_pid; offset:4; size:4; signed:1;
> field:int common_padding; offset:8; size:4; signed:1;
>
> field:unsigned long __probe_ip; offset:12; size:4; signed:0;
> field:u32 arg1; offset:16; size:4; signed:0;
> field:u32 arg2; offset:20; size:4; signed:0;
>
> print fmt: "(%lx) arg1=%lx arg2=%lx", REC->__probe_ip, REC->arg1, REC->arg2
> [root@f14kvm tracing]#
>
> Will update the Documentation file with correct output of "cat
> uprobe_events". Do you want the format file to be added to the
> Documentation?

Yes, I want, please :)

Thank you!


--
Masami HIRAMATSU
Software Platform Research Dept. Linux Technology Center
Hitachi, Ltd., Yokohama Research Laboratory
E-mail: masami.hiramatsu.pt@xxxxxxxxxxx
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