[PATCH 6/7] perf probe: Check the orphaned -x option

From: Arnaldo Carvalho de Melo
Date: Fri Apr 10 2015 - 17:41:19 EST


From: Masami Hiramatsu <masami.hiramatsu.pt@xxxxxxxxxxx>

To avoid probing in unintended binary, the orphaned -x option must be
checked and warned.

Without this patch, following command sets up the probe in the kernel.

-----
# perf probe -a strcpy -x ./perf
Added new event:
probe:strcpy (on strcpy)

You can now use it in all perf tools, such as:

perf record -e probe:strcpy -aR sleep 1
-----

But in this case, it seems that the user may want to probe in the perf
binary. With this patch, perf-probe correctly handles the orphaned -x.

-----
# perf probe -a strcpy -x ./perf
Error: -x/-m must follow the probe definitions.
...
-----

Reported-by: Jiri Olsa <jolsa@xxxxxxxxxx>
Acked-by: Jiri Olsa <jolsa@xxxxxxxxxx>
Cc: David Ahern <dsahern@xxxxxxxxx>
Cc: Namhyung Kim <namhyung@xxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Link: http://lkml.kernel.org/r/20150401102541.17137.75477.stgit@xxxxxxxxxxxxxxxxxxxxx
Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@xxxxxxxxxxx>
Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
---
tools/perf/builtin-probe.c | 10 ++++++++++
1 file changed, 10 insertions(+)

diff --git a/tools/perf/builtin-probe.c b/tools/perf/builtin-probe.c
index 2df23e177da5..f7b1af67e9f6 100644
--- a/tools/perf/builtin-probe.c
+++ b/tools/perf/builtin-probe.c
@@ -56,6 +56,7 @@ static struct {
bool mod_events;
bool uprobes;
bool quiet;
+ bool target_used;
int nevents;
struct perf_probe_event events[MAX_PROBES];
struct strlist *dellist;
@@ -82,6 +83,7 @@ static int parse_probe_event(const char *str)
pev->target = strdup(params.target);
if (!pev->target)
return -ENOMEM;
+ params.target_used = true;
}

/* Parse a perf-probe command into event */
@@ -107,6 +109,7 @@ static int set_target(const char *ptr)
params.target = strdup(ptr);
if (!params.target)
return -ENOMEM;
+ params.target_used = false;

found = 1;
buf = ptr + (strlen(ptr) - 3);
@@ -207,6 +210,7 @@ static int opt_set_target(const struct option *opt, const char *str,
}
free(params.target);
params.target = tmp;
+ params.target_used = false;
ret = 0;
}

@@ -491,6 +495,12 @@ __cmd_probe(int argc, const char **argv, const char *prefix __maybe_unused)
}

if (params.nevents) {
+ /* Ensure the last given target is used */
+ if (params.target && !params.target_used) {
+ pr_warning(" Error: -x/-m must follow the probe definitions.\n");
+ usage_with_options(probe_usage, options);
+ }
+
ret = add_perf_probe_events(params.events, params.nevents,
params.max_probe_points,
params.force_add);
--
1.9.3

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