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

From: Srikar Dronamraju
Date: Thu Apr 12 2012 - 10:57:26 EST


> > +
> > + # 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?

--
Thanks and Regards
Srikar

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/