perf parse: Fix potential memory leak when handling tracepoint errors

An error may be in place when tracepoint_error is called, use
parse_events__handle_error to avoid a memory leak and to capture the
first and last error. Error detected by LLVM's libFuzzer using the
following event:

$ perf stat -e 'msr/event/,f:e'
event syntax error: 'msr/event/,f:e'
                     \___ can't access trace events

Error:  No permissions to read /sys/kernel/debug/tracing/events/f/e
Hint:   Try 'sudo mount -o remount,mode=755 /sys/kernel/debug/tracing/'

Initial error:
event syntax error: 'msr/event/,f:e'
                                \___ no value assigned for term
Run 'perf list' for a list of valid events

 Usage: perf stat [<options>] [<command>]

    -e, --event <event>   event selector. use 'perf list' to list available events

Signed-off-by: Ian Rogers <irogers@google.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Jin Yao <yao.jin@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: clang-built-linux@googlegroups.com
Link: http://lore.kernel.org/lkml/20191120180925.21787-1-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
This commit is contained in:
Ian Rogers 2019-11-20 10:09:25 -08:00 committed by Arnaldo Carvalho de Melo
parent 358f98ee8a
commit 4584f084aa

View File

@ -511,6 +511,7 @@ int parse_events_add_cache(struct list_head *list, int *idx,
static void tracepoint_error(struct parse_events_error *e, int err,
const char *sys, const char *name)
{
const char *str;
char help[BUFSIZ];
if (!e)
@ -524,18 +525,18 @@ static void tracepoint_error(struct parse_events_error *e, int err,
switch (err) {
case EACCES:
e->str = strdup("can't access trace events");
str = "can't access trace events";
break;
case ENOENT:
e->str = strdup("unknown tracepoint");
str = "unknown tracepoint";
break;
default:
e->str = strdup("failed to add tracepoint");
str = "failed to add tracepoint";
break;
}
tracing_path__strerror_open_tp(err, help, sizeof(help), sys, name);
e->help = strdup(help);
parse_events__handle_error(e, 0, strdup(str), strdup(help));
}
static int add_tracepoint(struct list_head *list, int *idx,