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

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

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;





--
Masami Hiramatsu

Software Engineer
Hitachi Computer Products (America), Inc.
Software Solutions Division

e-mail: mhiramat@xxxxxxxxxx

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