Re: [PATCH v1] perf jit: Fix a few memory leaks

[Arnaldo Carvalho de Melo <acme@kernel.org>]

Em Mon, Apr 03, 2023 at 11:50:57AM -0700, Ian Rogers escreveu:
> As reported by leak sanitizer.
> 
> Signed-off-by: Ian Rogers <irogers@google.com>
> ---
>  tools/perf/util/genelf_debug.c | 48 +++++++++++++++++++++++++---------
>  tools/perf/util/jitdump.c      |  7 ++++-
>  2 files changed, 41 insertions(+), 14 deletions(-)
> 
> diff --git a/tools/perf/util/genelf_debug.c b/tools/perf/util/genelf_debug.c
> index dd40683bd4c0..bdcd37c34b64 100644
> --- a/tools/perf/util/genelf_debug.c
> +++ b/tools/perf/util/genelf_debug.c
> @@ -87,6 +87,12 @@ buffer_ext_init(struct buffer_ext *be)
>  	be->max_sz = 0;
>  }
>  
> +static void
> +buffer_ext_exit(struct buffer_ext *be)
> +{
> +	free(be->data);
> +}
> +
>  static inline size_t
>  buffer_ext_size(struct buffer_ext *be)
>  {
> @@ -494,21 +500,26 @@ jit_add_debug_info(Elf *e, uint64_t code_addr, void *debug, int nr_debug_entries
>  	buffer_ext_init(&da);
>  
>  	ret = jit_process_debug_info(code_addr, debug, nr_debug_entries, &dl, &da, &di);

Can we instead have:

	int ret = -1;
	if (jit_process_debug_info(code_addr, debug, nr_debug_entries, &dl, &da, &di))
		goto out;

And then remove all these ret = -1;

And...


> -	if (ret)
> -		return -1;
> +	if (ret) {
> +		ret = -1;
> +		goto out;
> +	}
> +
>  	/*
>  	 * setup .debug_line section
>  	 */
>  	scn = elf_newscn(e);
>  	if (!scn) {
>  		warnx("cannot create section");
> -		return -1;
> +		ret = -1;
> +		goto out;
>  	}
>  
>  	d = elf_newdata(scn);
>  	if (!d) {
>  		warnx("cannot get new data");
> -		return -1;
> +		ret = -1;
> +		goto out;
>  	}
>  
>  	d->d_align = 1;
> @@ -521,7 +532,8 @@ jit_add_debug_info(Elf *e, uint64_t code_addr, void *debug, int nr_debug_entries
>  	shdr = elf_getshdr(scn);
>  	if (!shdr) {
>  		warnx("cannot get section header");
> -		return -1;
> +		ret = -1;
> +		goto out;
>  	}
>  
>  	shdr->sh_name = 52; /* .debug_line */
> @@ -536,13 +548,15 @@ jit_add_debug_info(Elf *e, uint64_t code_addr, void *debug, int nr_debug_entries
>  	scn = elf_newscn(e);
>  	if (!scn) {
>  		warnx("cannot create section");
> -		return -1;
> +		ret = -1;
> +		goto out;
>  	}
>  
>  	d = elf_newdata(scn);
>  	if (!d) {
>  		warnx("cannot get new data");
> -		return -1;
> +		ret = -1;
> +		goto out;
>  	}
>  
>  	d->d_align = 1;
> @@ -555,7 +569,8 @@ jit_add_debug_info(Elf *e, uint64_t code_addr, void *debug, int nr_debug_entries
>  	shdr = elf_getshdr(scn);
>  	if (!shdr) {
>  		warnx("cannot get section header");
> -		return -1;
> +		ret = -1;
> +		goto out;
>  	}
>  
>  	shdr->sh_name = 64; /* .debug_info */
> @@ -570,13 +585,15 @@ jit_add_debug_info(Elf *e, uint64_t code_addr, void *debug, int nr_debug_entries
>  	scn = elf_newscn(e);
>  	if (!scn) {
>  		warnx("cannot create section");
> -		return -1;
> +		ret = -1;
> +		goto out;
>  	}
>  
>  	d = elf_newdata(scn);
>  	if (!d) {
>  		warnx("cannot get new data");
> -		return -1;
> +		ret = -1;
> +		goto out;
>  	}
>  
>  	d->d_align = 1;
> @@ -589,7 +606,8 @@ jit_add_debug_info(Elf *e, uint64_t code_addr, void *debug, int nr_debug_entries
>  	shdr = elf_getshdr(scn);
>  	if (!shdr) {
>  		warnx("cannot get section header");
> -		return -1;
> +		ret = -1;
> +		goto out;
>  	}
>  
>  	shdr->sh_name = 76; /* .debug_info */
> @@ -603,7 +621,11 @@ jit_add_debug_info(Elf *e, uint64_t code_addr, void *debug, int nr_debug_entries
>  	 */
>  	if (elf_update(e, ELF_C_WRITE) < 0) {
>  		warnx("elf_update debug failed");
> -		return -1;
> +		ret = -1;
>  	}
> -	return 0;

.. just add:
	ret = 0;

here?

> +out:
> +	buffer_ext_exit(&dl);
> +	buffer_ext_exit(&di);
> +	buffer_ext_exit(&da);
> +	return ret;
>  }
> diff --git a/tools/perf/util/jitdump.c b/tools/perf/util/jitdump.c
> index 0e033278fa12..28e49502db5e 100644
> --- a/tools/perf/util/jitdump.c
> +++ b/tools/perf/util/jitdump.c
> @@ -235,9 +235,11 @@ jit_open(struct jit_buf_desc *jd, const char *name)
>  	 */
>  	strcpy(jd->dir, name);
>  	dirname(jd->dir);
> +	free(buf);
>  
>  	return 0;
>  error:
> +	free(buf);
>  	funlockfile(jd->in);
>  	fclose(jd->in);
>  	return retval;
> @@ -523,7 +525,7 @@ static int jit_repipe_code_load(struct jit_buf_desc *jd, union jr_entry *jr)
>  
>  	ret = perf_event__process_mmap2(tool, event, &sample, jd->machine);
>  	if (ret)
> -		return ret;
> +		goto out;
>  
>  	ret = jit_inject_event(jd, event);
>  	/*
> @@ -532,6 +534,8 @@ static int jit_repipe_code_load(struct jit_buf_desc *jd, union jr_entry *jr)
>  	if (!ret)
>  		build_id__mark_dso_hit(tool, event, &sample, NULL, jd->machine);
>  
> +out:
> +	free(event);
>  	return ret;
>  }
>  
> @@ -874,6 +878,7 @@ jit_process(struct perf_session *session,
>  	}
>  
>  	nsinfo__put(jd.nsi);
> +	free(jd.buf);
>  
>  	return ret;
>  }
> -- 
> 2.40.0.348.gf938b09366-goog
> 

-- 

- Arnaldo