Re: [tip:perf/core] perf probe: Add --list option for listing currentprobe events

[Wang Liming]

Masami Hiramatsu wrote:
> Wang Liming wrote:
> > Hi Masami,
> >
> > tip-bot for Masami Hiramatsu wrote:
> > > Commit-ID:  4de189fe6e5ad8241f6f8709d2e2ba4c3aeae33a
> > > Gitweb:    
> > > http://git.kernel.org/tip/4de189fe6e5ad8241f6f8709d2e2ba4c3aeae33a
> > > Author:     Masami Hiramatsu <mhiramat@xxxxxxxxxx>
> > > AuthorDate: Mon, 30 Nov 2009 19:20:17 -0500
> > > Committer:  Ingo Molnar <mingo@xxxxxxx>
> > > CommitDate: Tue, 1 Dec 2009 08:20:02 +0100
> > >
> > > perf probe: Add --list option for listing current probe events
> > >
> > > Add --list option for listing currently defined probe events
> > > in the kernel. This shows events in below format;
> > >
> > >  [group:event]    <perf-probe probe-definition>
> > >
> > > for example:
> > >
> > >  [probe:schedule_0]    schedule+30 cpu
> > >
> > > Note that source file/line information is not supported yet.
> > > So even if you added a probe by line, it will be shown in
> > > <symbol+offset>.
> > ...
> > > +
> > > +    /* Scan event and group name. */
> > > +    ret = sscanf(argv[0], "%c:%m[^/ \t]/%m[^ \t]",
> > > +             &pr, group, event);
> > "%m" are typos?
>
> No, %m is glibc extension of sscanf modifier, which allocate
> memory for scanned string in sscanf. You can see "man sscanf"
> if your glibc is not so old (hopefully..). Please refer below;
>
> http://www.kernel.org/doc/man-pages/online/pages/man3/scanf.3.html#NOTES
Yes, my glibc is old so that "perf" can't be built. I'm using ubuntu 8.04.

Thanks a lot.
> Anyway, thank you for reviewing!
>
> > > +    if (ret != 3)
> > > +        semantic_error("Failed to parse event name: %s", argv[0]);
> > > +    pr_debug("Group:%s Event:%s probe:%c\n", *group, *event, pr);
> > > +
> > > +    if (!pp)
> > > +        goto end;
> > > +
> > > +    pp->retprobe = (pr == 'r');
> > > +
> > > +    /* Scan function name and offset */
> > > +    ret = sscanf(argv[1], "%m[^+]+%d", &pp->function, &pp->offset);
> > the same error? fix attached below.
> >
> > --
> >
> > diff --git a/tools/perf/util/probe-event.c b/tools/perf/util/probe-event.c
> > index e42f3ac..8d46521 100644
> > --- a/tools/perf/util/probe-event.c
> > +++ b/tools/perf/util/probe-event.c
> > @@ -199,8 +199,8 @@ void parse_trace_kprobe_event(const char *str, char
> > **group, char **event,
> >          semantic_error("Too less arguments.");
> >
> >      /* Scan event and group name. */
> > -    ret = sscanf(argv[0], "%c:%m[^/ \t]/%m[^ \t]",
> > -             &pr, group, event);
> > +    ret = sscanf(argv[0], "%c:%s[^/ \t]/%s[^ \t]",
> > +             &pr, *group, *event);
> >      if (ret != 3)
> >          semantic_error("Failed to parse event name: %s", argv[0]);
> >      pr_debug("Group:%s Event:%s probe:%c\n", *group, *event, pr);
> > @@ -211,7 +211,7 @@ void parse_trace_kprobe_event(const char *str, char
> > **group, char **event,
> >      pp->retprobe = (pr == 'r');
> >
> >      /* Scan function name and offset */
> > -    ret = sscanf(argv[1], "%m[^+]+%d", &pp->function, &pp->offset);
> > +    ret = sscanf(argv[1], "%s[^+]+%d", pp->function, &pp->offset);
> >      if (ret == 1)
> >          pp->offset = 0;

--
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/