Re: [PATCH v3 3/9] perf tools: ensure config and str in terms are unique

From: Jiri Olsa <jolsa@redhat.com>
To: Ian Rogers <irogers@google.com>
Cc: Peter Zijlstra <peterz@infradead.org>,
	Ingo Molnar <mingo@redhat.com>,
	Arnaldo Carvalho de Melo <acme@kernel.org>,
	Mark Rutland <mark.rutland@arm.com>,
	Alexander Shishkin <alexander.shishkin@linux.intel.com>,
	Namhyung Kim <namhyung@kernel.org>,
	Alexei Starovoitov <ast@kernel.org>,
	Daniel Borkmann <daniel@iogearbox.net>,
	Martin KaFai Lau <kafai@fb.com>, Song Liu <songliubraving@fb.com>,
	Yonghong Song <yhs@fb.com>, Andi Kleen <ak@linux.intel.com>,
	Jin Yao <yao.jin@linux.intel.com>,
	Adrian Hunter <adrian.hunter@intel.com>,
	Kan Liang <kan.liang@linux.intel.com>,
	John Garry <john.garry@huawei.com>,
	linux-kernel@vger.kernel.org, netdev@vger.kernel.org,
	bpf@vger.kernel.org, clang-built-linux@googlegroups.com,
	Stephane Eranian <eranian@google.com>
Subject: Re: [PATCH v3 3/9] perf tools: ensure config and str in terms are unique
Date: Fri, 25 Oct 2019 10:10:46 +0200	[thread overview]
Message-ID: <20191025081046.GG31679@krava> (raw)
In-Reply-To: <20191024190202.109403-4-irogers@google.com>

On Thu, Oct 24, 2019 at 12:01:56PM -0700, Ian Rogers wrote:
> Make it easier to release memory associated with parse event terms by
> duplicating the string for the config name and ensuring the val string
> is a duplicate.
> 
> Currently the parser may memory leak terms and this is addressed in a
> later patch.

please move that patch before this one 

thanks,
jirka

> 
> Signed-off-by: Ian Rogers <irogers@google.com>
> ---
>  tools/perf/util/parse-events.c | 51 ++++++++++++++++++++++++++++------
>  tools/perf/util/parse-events.y |  4 ++-
>  2 files changed, 45 insertions(+), 10 deletions(-)
> 
> diff --git a/tools/perf/util/parse-events.c b/tools/perf/util/parse-events.c
> index f0d50f079d2f..dc5862a663b5 100644
> --- a/tools/perf/util/parse-events.c
> +++ b/tools/perf/util/parse-events.c
> @@ -1430,7 +1430,6 @@ int parse_events_add_pmu(struct parse_events_state *parse_state,
>  int parse_events_multi_pmu_add(struct parse_events_state *parse_state,
>  			       char *str, struct list_head **listp)
>  {
> -	struct list_head *head;
>  	struct parse_events_term *term;
>  	struct list_head *list;
>  	struct perf_pmu *pmu = NULL;
> @@ -1447,19 +1446,30 @@ int parse_events_multi_pmu_add(struct parse_events_state *parse_state,
>  
>  		list_for_each_entry(alias, &pmu->aliases, list) {
>  			if (!strcasecmp(alias->name, str)) {
> +				struct list_head *head;
> +				char *config;
> +
>  				head = malloc(sizeof(struct list_head));
>  				if (!head)
>  					return -1;
>  				INIT_LIST_HEAD(head);
> -				if (parse_events_term__num(&term, PARSE_EVENTS__TERM_TYPE_USER,
> -							   str, 1, false, &str, NULL) < 0)
> +				config = strdup(str);
> +				if (!config)
> +					return -1;
> +				if (parse_events_term__num(&term,
> +						   PARSE_EVENTS__TERM_TYPE_USER,
> +						   config, 1, false, &config,
> +						   NULL) < 0) {
> +					free(list);
> +					free(config);
>  					return -1;
> +				}
>  				list_add_tail(&term->list, head);
>  
>  				if (!parse_events_add_pmu(parse_state, list,
>  							  pmu->name, head,
>  							  true, true)) {
> -					pr_debug("%s -> %s/%s/\n", str,
> +					pr_debug("%s -> %s/%s/\n", config,
>  						 pmu->name, alias->str);
>  					ok++;
>  				}
> @@ -1468,8 +1478,10 @@ int parse_events_multi_pmu_add(struct parse_events_state *parse_state,
>  			}
>  		}
>  	}
> -	if (!ok)
> +	if (!ok) {
> +		free(list);
>  		return -1;
> +	}
>  	*listp = list;
>  	return 0;
>  }
> @@ -2764,30 +2776,51 @@ int parse_events_term__sym_hw(struct parse_events_term **term,
>  			      char *config, unsigned idx)
>  {
>  	struct event_symbol *sym;
> +	char *str;
>  	struct parse_events_term temp = {
>  		.type_val  = PARSE_EVENTS__TERM_TYPE_STR,
>  		.type_term = PARSE_EVENTS__TERM_TYPE_USER,
> -		.config    = config ?: (char *) "event",
> +		.config    = config,
>  	};
>  
> +	if (!temp.config) {
> +		temp.config = strdup("event");
> +		if (!temp.config)
> +			return -ENOMEM;
> +	}
>  	BUG_ON(idx >= PERF_COUNT_HW_MAX);
>  	sym = &event_symbols_hw[idx];
>  
> -	return new_term(term, &temp, (char *) sym->symbol, 0);
> +	str = strdup(sym->symbol);
> +	if (!str)
> +		return -ENOMEM;
> +	return new_term(term, &temp, str, 0);
>  }
>  
>  int parse_events_term__clone(struct parse_events_term **new,
>  			     struct parse_events_term *term)
>  {
> +	char *str;
>  	struct parse_events_term temp = {
>  		.type_val  = term->type_val,
>  		.type_term = term->type_term,
> -		.config    = term->config,
> +		.config    = NULL,
>  		.err_term  = term->err_term,
>  		.err_val   = term->err_val,
>  	};
>  
> -	return new_term(new, &temp, term->val.str, term->val.num);
> +	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);
> +
> +	str = strdup(term->val.str);
> +	if (!str)
> +		return -ENOMEM;
> +	return new_term(new, &temp, str, 0);
>  }
>  
>  int parse_events_copy_term_list(struct list_head *old,
> diff --git a/tools/perf/util/parse-events.y b/tools/perf/util/parse-events.y
> index 48126ae4cd13..27d6b187c9b1 100644
> --- a/tools/perf/util/parse-events.y
> +++ b/tools/perf/util/parse-events.y
> @@ -644,9 +644,11 @@ PE_NAME array '=' PE_VALUE
>  PE_DRV_CFG_TERM
>  {
>  	struct parse_events_term *term;
> +	char *config = strdup($1);
>  
> +	ABORT_ON(!config);
>  	ABORT_ON(parse_events_term__str(&term, PARSE_EVENTS__TERM_TYPE_DRV_CFG,
> -					$1, $1, &@1, NULL));
> +					config, $1, &@1, NULL));
>  	$$ = term;
>  }
>  
> -- 
> 2.23.0.866.gb869b98d4c-goog
>