Re: [PATCHv10 2.6.35-rc6-tip 11/14] perf: perf interface for uprobes

[Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>]

Hi Srikar,

Srikar Dronamraju wrote:
> Enhances perf probe to accept pid and user vaddr.
> Provides very basic support for uprobes.
[...]
> @@ -162,6 +190,14 @@ static int try_to_find_probe_trace_events(struct perf_probe_event *pev,
>  	bool need_dwarf = perf_probe_event_need_dwarf(pev);
>  	int fd, ntevs;
>  
> +	if (pev->upid) {
> +		if (need_dwarf) {
> +			pr_warning("Debuginfo-analysis is not supported.\n");

This should be "Debuginfo-analysis is not supported with -p/--pid option.\n"

> +			return -ENOSYS;
> +		}
> +		return convert_name_to_addr(pev);
> +	}
> +



And I found a small bug.

# ./perf probe -vf -p 3199 "setenv %ax"
probe-definition(0): setenv %ax
symbol:setenv file:(null) line:0 offset:0 return:0 lazy:(null)
parsing arg: %ax into %ax
1 arguments
Opening /debug/tracing/uprobe_events write=1
Add new event:
Writing event: p:probe_3199/setenv 3199:0x47e680
 %ax
Failed to write event: Invalid argument
  Error: Failed to add events. (-1)

# ./perf probe -l
  probe_3199:setenv    (on 3199:0x000000000047e680)

When writing an event, there is a "\n" right after probe point (3199:0x47e680\n)

> @@ -1066,10 +1213,22 @@ char *synthesize_probe_trace_command(struct probe_trace_event *tev)
>  	if (buf == NULL)
>  		return NULL;
>  
> -	len = e_snprintf(buf, MAX_CMDLEN, "%c:%s/%s %s+%lu",
> -			 tp->retprobe ? 'r' : 'p',
> -			 tev->group, tev->event,
> -			 tp->symbol, tp->offset);
> +	if (tev->upid)
> +		len = e_snprintf(buf, MAX_CMDLEN, "%c:%s/%s %d:%s\n",

Here is a "\n".


Thank you,

-- 
Masami HIRAMATSU
2nd Research Dept.
Hitachi, Ltd., Systems Development Laboratory
E-mail: masami.hiramatsu.pt@hitachi.com