Re: [PATCH v3 6/9] perf tools: add destructors for parse event terms

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 6/9] perf tools: add destructors for parse event terms
Date: Fri, 25 Oct 2019 10:27:14 +0200	[thread overview]
Message-ID: <20191025082714.GH31679@krava> (raw)
In-Reply-To: <20191024190202.109403-7-irogers@google.com>

On Thu, Oct 24, 2019 at 12:01:59PM -0700, Ian Rogers wrote:
> If parsing fails then destructors are ran to clean the up the stack.
> Rename the head union member to make the term and evlist use cases more
> distinct, this simplifies matching the correct destructor.

nice did not know about this.. looks like it's been in bison for some time, right?

> 
> Signed-off-by: Ian Rogers <irogers@google.com>
> ---
>  tools/perf/util/parse-events.y | 69 +++++++++++++++++++++++-----------
>  1 file changed, 48 insertions(+), 21 deletions(-)
> 
> diff --git a/tools/perf/util/parse-events.y b/tools/perf/util/parse-events.y
> index 545ab7cefc20..4725b14b9db4 100644
> --- a/tools/perf/util/parse-events.y
> +++ b/tools/perf/util/parse-events.y
> @@ -12,6 +12,7 @@
>  #include <stdio.h>
>  #include <linux/compiler.h>
>  #include <linux/types.h>
> +#include <linux/zalloc.h>
>  #include "pmu.h"
>  #include "evsel.h"
>  #include "parse-events.h"
> @@ -37,6 +38,25 @@ static struct list_head* alloc_list()
>  	return list;
>  }
>  
> +static void free_list_evsel(struct list_head* list_evsel)
> +{
> +	struct perf_evsel *pos, *tmp;
> +
> +	list_for_each_entry_safe(pos, tmp, list_evsel, node) {
> +		list_del_init(&pos->node);
> +		perf_evsel__delete(pos);
> +	}
> +	free(list_evsel);

I think you need to iterate 'struct evsel' in here, not 'struct perf_evsel'

should be:

	struct evsel *evsel, *tmp;

	list_for_each_entry_safe(evsel, tmp, list_evsel, core.node) {
		list_del_init(&evsel->core.node);
		evsel__delete(evsel);
	}

thanks,
jirka

> +}
> +
> +static void free_term(struct parse_events_term *term)
> +{
> +	if (term->type_val == PARSE_EVENTS__TERM_TYPE_STR)
> +		free(term->val.str);
> +	zfree(&term->array.ranges);
> +	free(term);
> +}
> +
>  static void inc_group_count(struct list_head *list,
>  		       struct parse_events_state *parse_state)
>  {
> @@ -66,6 +86,7 @@ static void inc_group_count(struct list_head *list,
>  %type <num> PE_VALUE_SYM_TOOL
>  %type <num> PE_RAW
>  %type <num> PE_TERM
> +%type <num> value_sym
>  %type <str> PE_NAME
>  %type <str> PE_BPF_OBJECT
>  %type <str> PE_BPF_SOURCE
> @@ -76,37 +97,43 @@ static void inc_group_count(struct list_head *list,
>  %type <str> PE_EVENT_NAME
>  %type <str> PE_PMU_EVENT_PRE PE_PMU_EVENT_SUF PE_KERNEL_PMU_EVENT
>  %type <str> PE_DRV_CFG_TERM
> -%type <num> value_sym
> -%type <head> event_config
> -%type <head> opt_event_config
> -%type <head> opt_pmu_config
> +%destructor { free ($$); } <str>
>  %type <term> event_term
> -%type <head> event_pmu
> -%type <head> event_legacy_symbol
> -%type <head> event_legacy_cache
> -%type <head> event_legacy_mem
> -%type <head> event_legacy_tracepoint
> +%destructor { free_term ($$); } <term>
> +%type <list_terms> event_config
> +%type <list_terms> opt_event_config
> +%type <list_terms> opt_pmu_config
> +%destructor { parse_events_terms__delete ($$); } <list_terms>
> +%type <list_evsel> event_pmu
> +%type <list_evsel> event_legacy_symbol
> +%type <list_evsel> event_legacy_cache
> +%type <list_evsel> event_legacy_mem
> +%type <list_evsel> event_legacy_tracepoint
> +%type <list_evsel> event_legacy_numeric
> +%type <list_evsel> event_legacy_raw
> +%type <list_evsel> event_bpf_file
> +%type <list_evsel> event_def
> +%type <list_evsel> event_mod
> +%type <list_evsel> event_name
> +%type <list_evsel> event
> +%type <list_evsel> events
> +%type <list_evsel> group_def
> +%type <list_evsel> group
> +%type <list_evsel> groups
> +%destructor { free_list_evsel ($$); } <list_evsel>
>  %type <tracepoint_name> tracepoint_name
> -%type <head> event_legacy_numeric
> -%type <head> event_legacy_raw
> -%type <head> event_bpf_file
> -%type <head> event_def
> -%type <head> event_mod
> -%type <head> event_name
> -%type <head> event
> -%type <head> events
> -%type <head> group_def
> -%type <head> group
> -%type <head> groups
> +%destructor { free ($$.sys); free ($$.event); } <tracepoint_name>
>  %type <array> array
>  %type <array> array_term
>  %type <array> array_terms
> +%destructor { free ($$.ranges); } <array>
>  
>  %union
>  {
>  	char *str;
>  	u64 num;
> -	struct list_head *head;
> +	struct list_head *list_evsel;
> +	struct list_head *list_terms;
>  	struct parse_events_term *term;
>  	struct tracepoint_name {
>  		char *sys;
> -- 
> 2.23.0.866.gb869b98d4c-goog
> 