[PATCH] perf tools: fix potential memory leak

[PATCH] perf tools: fix potential memory leak

[Ian Rogers]

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>
---
 tools/perf/util/parse-events.c | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/tools/perf/util/parse-events.c b/tools/perf/util/parse-events.c
index 6bae9d6edc12..ecef5b8037b4 100644
--- a/tools/perf/util/parse-events.c
+++ b/tools/perf/util/parse-events.c
@@ -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,
-- 
2.24.0.432.g9d3f5f5b63-goog

Re: [PATCH] perf tools: fix potential memory leak

[Arnaldo Carvalho de Melo]

Em Wed, Nov 20, 2019 at 10:09:25AM -0800, Ian Rogers escreveu:
> 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

Thanks, applied.

- Arnaldo
 
> Signed-off-by: Ian Rogers <irogers@google.com>
> ---
>  tools/perf/util/parse-events.c | 9 +++++----
>  1 file changed, 5 insertions(+), 4 deletions(-)
> 
> diff --git a/tools/perf/util/parse-events.c b/tools/perf/util/parse-events.c
> index 6bae9d6edc12..ecef5b8037b4 100644
> --- a/tools/perf/util/parse-events.c
> +++ b/tools/perf/util/parse-events.c
> @@ -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,
> -- 
> 2.24.0.432.g9d3f5f5b63-goog

-- 

- Arnaldo

[tip: perf/core] perf parse: Fix potential memory leak when handling tracepoint errors

[tip-bot2 for Ian Rogers]

The following commit has been merged into the perf/core branch of tip:

Commit-ID:     4584f084aa9d8033d5911935837dbee7b082d0e9
Gitweb:        https://git.kernel.org/tip/4584f084aa9d8033d5911935837dbee7b082d0e9
Author:        Ian Rogers <irogers@google.com>
AuthorDate:    Wed, 20 Nov 2019 10:09:25 -08:00
Committer:     Arnaldo Carvalho de Melo <acme@redhat.com>
CommitterDate: Fri, 22 Nov 2019 10:48:14 -03:00

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>
---
 tools/perf/util/parse-events.c |  9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/tools/perf/util/parse-events.c b/tools/perf/util/parse-events.c
index 6c313c4..ed7c008 100644
--- a/tools/perf/util/parse-events.c
+++ b/tools/perf/util/parse-events.c
@@ -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,