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Date:   Thu, 2 Jan 2020 23:26:41 +0800
From:   Leo Yan <leo.yan@linaro.org>
To:     Arnaldo Carvalho de Melo <acme@redhat.com>,
        Peter Zijlstra <peterz@infradead.org>,
        Ingo Molnar <mingo@redhat.com>,
        Mark Rutland <mark.rutland@arm.com>,
        Alexander Shishkin <alexander.shishkin@linux.intel.com>,
        Jiri Olsa <jolsa@kernel.org>,
        Namhyung Kim <namhyung@kernel.org>,
        Ian Rogers <irogers@google.com>,
        Adrian Hunter <adrian.hunter@intel.com>,
        Andi Kleen <ak@linux.intel.com>, linux-kernel@vger.kernel.org,
        Mathieu Poirier <mathieu.poirier@linaro.org>,
        Mike Leach <mike.leach@linaro.org>,
        Suzuki K Poulose <suzuki.poulose@arm.com>
Subject: Re: [PATCH] perf parse: Copy string to perf_evsel_config_term
Message-ID: <20200102152641.GA31626@leoy-ThinkPad-X240s>
References: <20200102151326.31342-1-leo.yan@linaro.org>
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On Thu, Jan 02, 2020 at 11:13:26PM +0800, Leo Yan wrote:
> perf with CoreSight fails to record trace data with command:
> 
>   perf record -e cs_etm/@tmc_etr0/u --per-thread ls
>   failed to set sink "" on event cs_etm/@tmc_etr0/u with 21 (Is a
>   directory)/perf/
> 
> This failure is root caused with the commit 1dc925568f01 ("perf
> parse: Add a deep delete for parse event terms").
> 
> The log shows, cs_etm fails to parse the sink attribution; cs_etm event
> relies on the event configuration to pass sink name, but the event
> specific configuration data cannot be passed properly with flow:
> 
>   get_config_terms()
>     ADD_CONFIG_TERM(DRV_CFG, drv_cfg, term->val.str);
>       __t->val.drv_cfg = term->val.str;
>         `> __t->val.drv_cfg is assigned to term->val.str;
> 
>   parse_events_terms__purge()
>     parse_events_term__delete()
>       zfree(&term->val.str);
>         `> term->val.str is freed and assigned to NULL pointer;
> 
>   cs_etm_set_sink_attr()
>     sink = __t->val.drv_cfg;
>       `> sink string has been freed.
> 
> To fix this issue, in the function get_config_terms(), this patch
> changes from directly assignment pointer value for the strings to
> use strdup() for allocation a new duplicate string for the cases:
> 
>   perf_evsel_config_term::val.callgraph
>   perf_evsel_config_term::val.branch
>   perf_evsel_config_term::val.drv_cfg.
> 
> Fixes: 1dc925568f01 ("perf parse: Add a deep delete for parse event terms")
> Signed-off-by: Leo Yan <leo.yan@linaro.org>

Let me to loop Mathieu/Mike/Suzuki, sorry for spamming.

Thanks,
Leo

> ---
>  tools/perf/util/parse-events.c | 49 ++++++++++++++++++++--------------
>  1 file changed, 29 insertions(+), 20 deletions(-)
> 
> diff --git a/tools/perf/util/parse-events.c b/tools/perf/util/parse-events.c
> index ed7c008b9c8b..5972acdd40d6 100644
> --- a/tools/perf/util/parse-events.c
> +++ b/tools/perf/util/parse-events.c
> @@ -1220,7 +1220,6 @@ static int get_config_terms(struct list_head *head_config,
>  			    struct list_head *head_terms __maybe_unused)
>  {
>  #define ADD_CONFIG_TERM(__type, __name, __val)			\
> -do {								\
>  	struct perf_evsel_config_term *__t;			\
>  								\
>  	__t = zalloc(sizeof(*__t));				\
> @@ -1229,9 +1228,19 @@ do {								\
>  								\
>  	INIT_LIST_HEAD(&__t->list);				\
>  	__t->type       = PERF_EVSEL__CONFIG_TERM_ ## __type;	\
> -	__t->val.__name = __val;				\
>  	__t->weak	= term->weak;				\
> -	list_add_tail(&__t->list, head_terms);			\
> +	list_add_tail(&__t->list, head_terms)
> +
> +#define ADD_CONFIG_TERM_VAL(__type, __name, __val)		\
> +do {								\
> +	ADD_CONFIG_TERM(__type, __name, __val);			\
> +	__t->val.__name = __val;				\
> +} while (0)
> +
> +#define ADD_CONFIG_TERM_STR(__type, __name, __val)		\
> +do {								\
> +	ADD_CONFIG_TERM(__type, __name, __val);			\
> +	__t->val.__name = strdup(__val);			\
>  } while (0)
>  
>  	struct parse_events_term *term;
> @@ -1239,53 +1248,53 @@ do {								\
>  	list_for_each_entry(term, head_config, list) {
>  		switch (term->type_term) {
>  		case PARSE_EVENTS__TERM_TYPE_SAMPLE_PERIOD:
> -			ADD_CONFIG_TERM(PERIOD, period, term->val.num);
> +			ADD_CONFIG_TERM_VAL(PERIOD, period, term->val.num);
>  			break;
>  		case PARSE_EVENTS__TERM_TYPE_SAMPLE_FREQ:
> -			ADD_CONFIG_TERM(FREQ, freq, term->val.num);
> +			ADD_CONFIG_TERM_VAL(FREQ, freq, term->val.num);
>  			break;
>  		case PARSE_EVENTS__TERM_TYPE_TIME:
> -			ADD_CONFIG_TERM(TIME, time, term->val.num);
> +			ADD_CONFIG_TERM_VAL(TIME, time, term->val.num);
>  			break;
>  		case PARSE_EVENTS__TERM_TYPE_CALLGRAPH:
> -			ADD_CONFIG_TERM(CALLGRAPH, callgraph, term->val.str);
> +			ADD_CONFIG_TERM_STR(CALLGRAPH, callgraph, term->val.str);
>  			break;
>  		case PARSE_EVENTS__TERM_TYPE_BRANCH_SAMPLE_TYPE:
> -			ADD_CONFIG_TERM(BRANCH, branch, term->val.str);
> +			ADD_CONFIG_TERM_STR(BRANCH, branch, term->val.str);
>  			break;
>  		case PARSE_EVENTS__TERM_TYPE_STACKSIZE:
> -			ADD_CONFIG_TERM(STACK_USER, stack_user, term->val.num);
> +			ADD_CONFIG_TERM_VAL(STACK_USER, stack_user, term->val.num);
>  			break;
>  		case PARSE_EVENTS__TERM_TYPE_INHERIT:
> -			ADD_CONFIG_TERM(INHERIT, inherit, term->val.num ? 1 : 0);
> +			ADD_CONFIG_TERM_VAL(INHERIT, inherit, term->val.num ? 1 : 0);
>  			break;
>  		case PARSE_EVENTS__TERM_TYPE_NOINHERIT:
> -			ADD_CONFIG_TERM(INHERIT, inherit, term->val.num ? 0 : 1);
> +			ADD_CONFIG_TERM_VAL(INHERIT, inherit, term->val.num ? 0 : 1);
>  			break;
>  		case PARSE_EVENTS__TERM_TYPE_MAX_STACK:
> -			ADD_CONFIG_TERM(MAX_STACK, max_stack, term->val.num);
> +			ADD_CONFIG_TERM_VAL(MAX_STACK, max_stack, term->val.num);
>  			break;
>  		case PARSE_EVENTS__TERM_TYPE_MAX_EVENTS:
> -			ADD_CONFIG_TERM(MAX_EVENTS, max_events, term->val.num);
> +			ADD_CONFIG_TERM_VAL(MAX_EVENTS, max_events, term->val.num);
>  			break;
>  		case PARSE_EVENTS__TERM_TYPE_OVERWRITE:
> -			ADD_CONFIG_TERM(OVERWRITE, overwrite, term->val.num ? 1 : 0);
> +			ADD_CONFIG_TERM_VAL(OVERWRITE, overwrite, term->val.num ? 1 : 0);
>  			break;
>  		case PARSE_EVENTS__TERM_TYPE_NOOVERWRITE:
> -			ADD_CONFIG_TERM(OVERWRITE, overwrite, term->val.num ? 0 : 1);
> +			ADD_CONFIG_TERM_VAL(OVERWRITE, overwrite, term->val.num ? 0 : 1);
>  			break;
>  		case PARSE_EVENTS__TERM_TYPE_DRV_CFG:
> -			ADD_CONFIG_TERM(DRV_CFG, drv_cfg, term->val.str);
> +			ADD_CONFIG_TERM_STR(DRV_CFG, drv_cfg, term->val.str);
>  			break;
>  		case PARSE_EVENTS__TERM_TYPE_PERCORE:
> -			ADD_CONFIG_TERM(PERCORE, percore,
> +			ADD_CONFIG_TERM_VAL(PERCORE, percore,
>  					term->val.num ? true : false);
>  			break;
>  		case PARSE_EVENTS__TERM_TYPE_AUX_OUTPUT:
> -			ADD_CONFIG_TERM(AUX_OUTPUT, aux_output, term->val.num ? 1 : 0);
> +			ADD_CONFIG_TERM_VAL(AUX_OUTPUT, aux_output, term->val.num ? 1 : 0);
>  			break;
>  		case PARSE_EVENTS__TERM_TYPE_AUX_SAMPLE_SIZE:
> -			ADD_CONFIG_TERM(AUX_SAMPLE_SIZE, aux_sample_size, term->val.num);
> +			ADD_CONFIG_TERM_VAL(AUX_SAMPLE_SIZE, aux_sample_size, term->val.num);
>  			break;
>  		default:
>  			break;
> @@ -1322,7 +1331,7 @@ static int get_config_chgs(struct perf_pmu *pmu, struct list_head *head_config,
>  	}
>  
>  	if (bits)
> -		ADD_CONFIG_TERM(CFG_CHG, cfg_chg, bits);
> +		ADD_CONFIG_TERM_VAL(CFG_CHG, cfg_chg, bits);
>  
>  #undef ADD_CONFIG_TERM
>  	return 0;
> -- 
> 2.17.1
>