[tip: perf/core] perf parse: Add parse events handle error

tip-bot2 for Ian Rogers
2019-11-12T11:19:37Z

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

Commit-ID: 448d732cefb3b4017f687f18c300e48354ddc240
Gitweb: https://git.kernel.org/tip/448d732cefb3b4017f687f18c300e48354ddc240
Author: Ian Rogers <irogers@google.com>
AuthorDate: Wed, 30 Oct 2019 15:34:39 -07:00
Committer: Arnaldo Carvalho de Melo <acme@redhat.com>
CommitterDate: Wed, 06 Nov 2019 15:49:40 -03:00

perf parse: Add parse events handle error

Parse event error handling may overwrite one error string with another
creating memory leaks. Introduce a helper routine that warns about
multiple error messages as well as avoiding the memory leak.

A reproduction of this problem can be seen with:

perf stat -e c/c/

After this change this produces:
WARNING: multiple event parsing errors
event syntax error: 'c/c/'
\___ unknown term

valid terms: event,filter_rem,filter_opc0,edge,filter_isoc,filter_tid,filter_loc,filter_nc,inv,umask,filter_opc1,tid_en,thresh,filter_all_op,filter_not_nm,filter_state,filter_nm,config,config1,config2,name,period,percore
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>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Jin Yao <yao.jin@linux.intel.com>
Cc: John Garry <john.garry@huawei.com>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Martin KaFai Lau <kafai@fb.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Song Liu <songliubraving@fb.com>
Cc: Stephane Eranian <eranian@google.com>
Cc: Yonghong Song <yhs@fb.com>
Cc: bpf@vger.kernel.org
Cc: clang-built-linux@googlegroups.com
Cc: netdev@vger.kernel.org
Link: http://lore.kernel.org/lkml/20191030223448.12930-2-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
tools/perf/util/parse-events.c | 82 ++++++++++++++++++++-------------
tools/perf/util/parse-events.h | 2 +-
tools/perf/util/pmu.c | 30 +++++++-----
3 files changed, 71 insertions(+), 43 deletions(-)

diff --git a/tools/perf/util/parse-events.c b/tools/perf/util/parse-events.c
index d36b812..03e54a2 100644
--- a/tools/perf/util/parse-events.c
+++ b/tools/perf/util/parse-events.c
@@ -182,6 +182,20 @@ static int tp_event_has_id(const char *dir_path, struct dirent *evt_dir)

#define MAX_EVENT_LENGTH 512

+void parse_events__handle_error(struct parse_events_error *err, int idx,
+ char *str, char *help)
+{
+ if (WARN(!str, "WARNING: failed to provide error string\n")) {
+ free(help);
+ return;
+ }
+ WARN_ONCE(err->str, "WARNING: multiple event parsing errors\n");
+ err->idx = idx;
+ free(err->str);
+ err->str = str;
+ free(err->help);
+ err->help = help;
+}

struct tracepoint_path *tracepoint_id_to_path(u64 config)
{
@@ -932,11 +946,11 @@ static int check_type_val(struct parse_events_term *term,
return 0;

if (err) {
- err->idx = term->err_val;
- if (type == PARSE_EVENTS__TERM_TYPE_NUM)
- err->str = strdup("expected numeric value");
- else
- err->str = strdup("expected string value");
+ parse_events__handle_error(err, term->err_val,
+ type == PARSE_EVENTS__TERM_TYPE_NUM
+ ? strdup("expected numeric value")
+ : strdup("expected string value"),
+ NULL);
}
return -EINVAL;
}
@@ -972,8 +986,11 @@ static bool config_term_shrinked;
static bool
config_term_avail(int term_type, struct parse_events_error *err)
{
+ char *err_str;
+
if (term_type < 0 || term_type >= __PARSE_EVENTS__TERM_TYPE_NR) {
- err->str = strdup("Invalid term_type");
+ parse_events__handle_error(err, -1,
+ strdup("Invalid term_type"), NULL);
return false;
}
if (!config_term_shrinked)
@@ -992,9 +1009,9 @@ config_term_avail(int term_type, struct parse_events_error *err)
return false;

/* term_type is validated so indexing is safe */
- if (asprintf(&err->str, "'%s' is not usable in 'perf stat'",
- config_term_names[term_type]) < 0)
- err->str = NULL;
+ if (asprintf(&err_str, "'%s' is not usable in 'perf stat'",
+ config_term_names[term_type]) >= 0)
+ parse_events__handle_error(err, -1, err_str, NULL);
return false;
}
}
@@ -1036,17 +1053,20 @@ do { \
case PARSE_EVENTS__TERM_TYPE_BRANCH_SAMPLE_TYPE:
CHECK_TYPE_VAL(STR);
if (strcmp(term->val.str, "no") &&
- parse_branch_str(term->val.str, &attr->branch_sample_type)) {
- err->str = strdup("invalid branch sample type");
- err->idx = term->err_val;
+ parse_branch_str(term->val.str,
+ &attr->branch_sample_type)) {
+ parse_events__handle_error(err, term->err_val,
+ strdup("invalid branch sample type"),
+ NULL);
return -EINVAL;
}
break;
case PARSE_EVENTS__TERM_TYPE_TIME:
CHECK_TYPE_VAL(NUM);
if (term->val.num > 1) {
- err->str = strdup("expected 0 or 1");
- err->idx = term->err_val;
+ parse_events__handle_error(err, term->err_val,
+ strdup("expected 0 or 1"),
+ NULL);
return -EINVAL;
}
break;
@@ -1080,8 +1100,9 @@ do { \
case PARSE_EVENTS__TERM_TYPE_PERCORE:
CHECK_TYPE_VAL(NUM);
if ((unsigned int)term->val.num > 1) {
- err->str = strdup("expected 0 or 1");
- err->idx = term->err_val;
+ parse_events__handle_error(err, term->err_val,
+ strdup("expected 0 or 1"),
+ NULL);
return -EINVAL;
}
break;
@@ -1089,9 +1110,9 @@ do { \
CHECK_TYPE_VAL(NUM);
break;
default:
- err->str = strdup("unknown term");
- err->idx = term->err_term;
- err->help = parse_events_formats_error_string(NULL);
+ parse_events__handle_error(err, term->err_term,
+ strdup("unknown term"),
+ parse_events_formats_error_string(NULL));
return -EINVAL;
}

@@ -1142,9 +1163,9 @@ static int config_term_tracepoint(struct perf_event_attr *attr,
return config_term_common(attr, term, err);
default:
if (err) {
- err->idx = term->err_term;
- err->str = strdup("unknown term");
- err->help = strdup("valid terms: call-graph,stack-size\n");
+ parse_events__handle_error(err, term->err_term,
+ strdup("unknown term"),
+ strdup("valid terms: call-graph,stack-size\n"));
}
return -EINVAL;
}
@@ -1323,10 +1344,12 @@ int parse_events_add_pmu(struct parse_events_state *parse_state,

pmu = perf_pmu__find(name);
if (!pmu) {
- if (asprintf(&err->str,
+ char *err_str;
+
+ if (asprintf(&err_str,
"Cannot find PMU `%s'. Missing kernel support?",
- name) < 0)
- err->str = NULL;
+ name) >= 0)
+ parse_events__handle_error(err, -1, err_str, NULL);
return -EINVAL;
}

@@ -2802,13 +2825,10 @@ void parse_events__clear_array(struct parse_events_array *a)
void parse_events_evlist_error(struct parse_events_state *parse_state,
int idx, const char *str)
{
- struct parse_events_error *err = parse_state->error;
-
- if (!err)
+ if (!parse_state->error)
return;
- err->idx = idx;
- err->str = strdup(str);
- WARN_ONCE(!err->str, "WARNING: failed to allocate error string");
+
+ parse_events__handle_error(parse_state->error, idx, strdup(str), NULL);
}

static void config_terms_list(char *buf, size_t buf_sz)
diff --git a/tools/perf/util/parse-events.h b/tools/perf/util/parse-events.h
index 769e07c..34f58d2 100644
--- a/tools/perf/util/parse-events.h
+++ b/tools/perf/util/parse-events.h
@@ -124,6 +124,8 @@ struct parse_events_state {
struct list_head *terms;
};

+void parse_events__handle_error(struct parse_events_error *err, int idx,
+ char *str, char *help);
void parse_events__shrink_config_terms(void);
int parse_events__is_hardcoded_term(struct parse_events_term *term);
int parse_events_term__num(struct parse_events_term **term,
diff --git a/tools/perf/util/pmu.c b/tools/perf/util/pmu.c
index adbe97e..f9f427d 100644
--- a/tools/perf/util/pmu.c
+++ b/tools/perf/util/pmu.c
@@ -1050,9 +1050,9 @@ static int pmu_config_term(struct list_head *formats,
if (err) {
char *pmu_term = pmu_formats_string(formats);

- err->idx = term->err_term;
- err->str = strdup("unknown term");
- err->help = parse_events_formats_error_string(pmu_term);
+ parse_events__handle_error(err, term->err_term,
+ strdup("unknown term"),
+ parse_events_formats_error_string(pmu_term));
free(pmu_term);
}
return -EINVAL;
@@ -1080,8 +1080,9 @@ static int pmu_config_term(struct list_head *formats,
if (term->no_value &&
bitmap_weight(format->bits, PERF_PMU_FORMAT_BITS) > 1) {
if (err) {
- err->idx = term->err_val;
- err->str = strdup("no value assigned for term");
+ parse_events__handle_error(err, term->err_val,
+ strdup("no value assigned for term"),
+ NULL);
}
return -EINVAL;
}
@@ -1094,8 +1095,9 @@ static int pmu_config_term(struct list_head *formats,
term->config, term->val.str);
}
if (err) {
- err->idx = term->err_val;
- err->str = strdup("expected numeric value");
+ parse_events__handle_error(err, term->err_val,
+ strdup("expected numeric value"),
+ NULL);
}
return -EINVAL;
}
@@ -1108,11 +1110,15 @@ static int pmu_config_term(struct list_head *formats,
max_val = pmu_format_max_value(format->bits);
if (val > max_val) {
if (err) {
- err->idx = term->err_val;
- if (asprintf(&err->str,
- "value too big for format, maximum is %llu",
- (unsigned long long)max_val) < 0)
- err->str = strdup("value too big for format");
+ char *err_str;
+
+ parse_events__handle_error(err, term->err_val,
+ asprintf(&err_str,
+ "value too big for format, maximum is %llu",
+ (unsigned long long)max_val) < 0
+ ? strdup("value too big for format")
+ : err_str,
+ NULL);
return -EINVAL;
}
/*