Em Thu, Jun 11, 2020 at 09:42:34AM +0800, Chen Wandun escreveu:
> Fix potential memory leak in function parse_events_term__sym_hw()
> and parse_events_term__clone().
>
> 1. Free memory when errors occur.
> 2. Function new_term may return error, so it is need to free memory
> when the return value is negative.
Try to fix one thing per patch, i.e. first the most obvious one, then
the other that requires going thru the new_term() logic, i.e. first
this, which is super easy to review:
diff --git a/tools/perf/util/parse-events.c b/tools/perf/util/parse-events.c
index c4906a6a9f1a..3ada3874a90a 100644
--- a/tools/perf/util/parse-events.c
+++ b/tools/perf/util/parse-events.c
@@ -2958,8 +2958,10 @@ int parse_events_term__sym_hw(struct parse_events_term
**term,
sym = &event_symbols_hw[idx];
str = strdup(sym->symbol);
- if (!str)
+ if (!str) {
+ zfree(&temp.config);
return -ENOMEM;
+ }
return new_term(term, &temp, str, 0);
}
@@ -2984,8 +2986,10 @@ int parse_events_term__clone(struct parse_events_term
**new,
return new_term(new, &temp, NULL, term->val.num);
str = strdup(term->val.str);
- if (!str)
+ if (!str) {
+ zfree(&temp.config);
return -ENOMEM;
+ }
return new_term(new, &temp, str, 0);
}
Then you go to the one that requires the reviewer (now or in the future,
trying to figure out why something broke) to look at the new_term()
code, ok?
- Arnaldo
> Signed-off-by: Chen Wandun <chenwan...@huawei.com>
> ---
> tools/perf/util/parse-events.c | 40 +++++++++++++++++++++++++++++-----
> 1 file changed, 34 insertions(+), 6 deletions(-)
>
> diff --git a/tools/perf/util/parse-events.c b/tools/perf/util/parse-events.c
> index 3decbb203846..3491c18edd71 100644
> --- a/tools/perf/util/parse-events.c
> +++ b/tools/perf/util/parse-events.c
> @@ -2947,6 +2947,7 @@ int parse_events_term__sym_hw(struct parse_events_term
> **term,
> .type_term = PARSE_EVENTS__TERM_TYPE_USER,
> .config = config,
> };
> + int ret;
>
> if (!temp.config) {
> temp.config = strdup("event");
> @@ -2957,9 +2958,20 @@ int parse_events_term__sym_hw(struct parse_events_term
> **term,
> sym = &event_symbols_hw[idx];
>
> str = strdup(sym->symbol);
> - if (!str)
> + if (!str) {
> + if (!config)
> + free(temp.config);
> return -ENOMEM;
> - return new_term(term, &temp, str, 0);
> + }
> +
> + ret = new_term(term, &temp, str, 0);
> + if (ret < 0) {
> + free(str);
> + if (!config)
> + free(temp.config);
> + }
> +
> + return ret;
> }
>
> int parse_events_term__clone(struct parse_events_term **new,
> @@ -2973,19 +2985,35 @@ int parse_events_term__clone(struct parse_events_term
> **new,
> .err_term = term->err_term,
> .err_val = term->err_val,
> };
> + int ret;
>
> if (term->config) {
> temp.config = strdup(term->config);
> if (!temp.config)
> return -ENOMEM;
> }
> - if (term->type_val == PARSE_EVENTS__TERM_TYPE_NUM)
> - return new_term(new, &temp, NULL, term->val.num);
> + if (term->type_val == PARSE_EVENTS__TERM_TYPE_NUM) {
> + ret = new_term(new, &temp, NULL, term->val.num);
> + if (ret < 0 && term->config)
> + free(temp.config);
> + return ret;
> + }
>
> str = strdup(term->val.str);
> - if (!str)
> + if (!str) {
> + if (term->config)
> + free(temp.config);
> return -ENOMEM;
> - return new_term(new, &temp, str, 0);
> + }
> +
> + ret = new_term(new, &temp, str, 0);
> + if (ret < 0) {
> + free(str);
> + if (term->config)
> + free(temp.config);
> + }
> +
> + return ret;
> }
>
> void parse_events_term__delete(struct parse_events_term *term)
> --
> 2.17.1
>
--
- Arnaldo
