[PATCH v3 1/2] perf pmu: Make parser reentrant

[PATCH v3 1/2] perf pmu: Make parser reentrant

[Ian Rogers]

By default bison uses global state for compatibility with yacc. Make
the parser reentrant so that it may be used in asynchronous and
multithreaded situations.

Signed-off-by: Ian Rogers <irogers@google.com>
---
 tools/perf/util/pmu.c | 26 ++++++++++++++++++++------
 tools/perf/util/pmu.h |  2 +-
 tools/perf/util/pmu.l | 17 ++++++++++++-----
 tools/perf/util/pmu.y |  5 ++++-
 4 files changed, 37 insertions(+), 13 deletions(-)

diff --git a/tools/perf/util/pmu.c b/tools/perf/util/pmu.c
index 78a407b42ad1..96ef317bac41 100644
--- a/tools/perf/util/pmu.c
+++ b/tools/perf/util/pmu.c
@@ -24,6 +24,8 @@
 #include "evsel.h"
 #include "pmu.h"
 #include "pmus.h"
+#include "pmu-bison.h"
+#include "pmu-flex.h"
 #include "parse-events.h"
 #include "print-events.h"
 #include "header.h"
@@ -57,9 +59,6 @@ struct perf_pmu_format {
 	struct list_head list;
 };
 
-int perf_pmu_parse(struct list_head *list, char *name);
-extern FILE *perf_pmu_in;
-
 static bool hybrid_scanned;
 
 static struct perf_pmu *perf_pmu__find2(int dirfd, const char *name);
@@ -81,6 +80,8 @@ int perf_pmu__format_parse(int dirfd, struct list_head *head)
 	while (!ret && (evt_ent = readdir(format_dir))) {
 		char *name = evt_ent->d_name;
 		int fd;
+		void *scanner;
+		FILE *file;
 
 		if (!strcmp(name, ".") || !strcmp(name, ".."))
 			continue;
@@ -91,9 +92,22 @@ int perf_pmu__format_parse(int dirfd, struct list_head *head)
 		if (fd < 0)
 			break;
 
-		perf_pmu_in = fdopen(fd, "r");
-		ret = perf_pmu_parse(head, name);
-		fclose(perf_pmu_in);
+		file = fdopen(fd, "r");
+		if (!file) {
+			close(fd);
+			break;
+		}
+
+		ret = perf_pmu_lex_init(&scanner);
+		if (ret) {
+			fclose(file);
+			break;
+		}
+
+		perf_pmu_set_in(file, scanner);
+		ret = perf_pmu_parse(head, name, scanner);
+		perf_pmu_lex_destroy(scanner);
+		fclose(file);
 	}
 
 	closedir(format_dir);
diff --git a/tools/perf/util/pmu.h b/tools/perf/util/pmu.h
index 32c3a75bca0e..d53618c65c92 100644
--- a/tools/perf/util/pmu.h
+++ b/tools/perf/util/pmu.h
@@ -206,7 +206,7 @@ int perf_pmu__check_alias(struct perf_pmu *pmu, struct list_head *head_terms,
 			  struct perf_pmu_info *info);
 struct list_head *perf_pmu__alias(struct perf_pmu *pmu,
 				  struct list_head *head_terms);
-void perf_pmu_error(struct list_head *list, char *name, char const *msg);
+void perf_pmu_error(struct list_head *list, char *name, void *scanner, char const *msg);
 
 int perf_pmu__new_format(struct list_head *list, char *name,
 			 int config, unsigned long *bits);
diff --git a/tools/perf/util/pmu.l b/tools/perf/util/pmu.l
index 58b4926cfaca..67b247be693b 100644
--- a/tools/perf/util/pmu.l
+++ b/tools/perf/util/pmu.l
@@ -1,4 +1,6 @@
 %option prefix="perf_pmu_"
+%option reentrant
+%option bison-bridge
 
 %{
 #include <stdlib.h>
@@ -6,16 +8,21 @@
 #include "pmu.h"
 #include "pmu-bison.h"
 
-static int value(int base)
+char *perf_pmu_get_text(yyscan_t yyscanner);
+YYSTYPE *perf_pmu_get_lval(yyscan_t yyscanner);
+
+static int value(yyscan_t scanner, int base)
 {
+	YYSTYPE *yylval = perf_pmu_get_lval(scanner);
+	char *text = perf_pmu_get_text(scanner);
 	long num;
 
 	errno = 0;
-	num = strtoul(perf_pmu_text, NULL, base);
+	num = strtoul(text, NULL, base);
 	if (errno)
 		return PP_ERROR;
 
-	perf_pmu_lval.num = num;
+	yylval->num = num;
 	return PP_VALUE;
 }
 
@@ -25,7 +32,7 @@ num_dec         [0-9]+
 
 %%
 
-{num_dec}	{ return value(10); }
+{num_dec}	{ return value(yyscanner, 10); }
 config		{ return PP_CONFIG; }
 -		{ return '-'; }
 :		{ return ':'; }
@@ -35,7 +42,7 @@ config		{ return PP_CONFIG; }
 
 %%
 
-int perf_pmu_wrap(void)
+int perf_pmu_wrap(void *scanner __maybe_unused)
 {
 	return 1;
 }
diff --git a/tools/perf/util/pmu.y b/tools/perf/util/pmu.y
index e675d79a0274..dff4e892ac4d 100644
--- a/tools/perf/util/pmu.y
+++ b/tools/perf/util/pmu.y
@@ -1,6 +1,8 @@
-
+%define api.pure full
 %parse-param {struct list_head *format}
 %parse-param {char *name}
+%parse-param {void *scanner}
+%lex-param {void* scanner}
 
 %{
 
@@ -78,6 +80,7 @@ PP_VALUE
 
 void perf_pmu_error(struct list_head *list __maybe_unused,
 		    char *name __maybe_unused,
+		    void *scanner __maybe_unused,
 		    char const *msg __maybe_unused)
 {
 }
-- 
2.40.0.348.gf938b09366-goog

[PATCH v3 2/2] perf pmu: Fix a few potential fd leaks

[Ian Rogers]

Ensure fd is closed on error paths.

Signed-off-by: Ian Rogers <irogers@google.com>
---
 tools/perf/util/pmu.c | 12 ++++++++++--
 1 file changed, 10 insertions(+), 2 deletions(-)

diff --git a/tools/perf/util/pmu.c b/tools/perf/util/pmu.c
index 96ef317bac41..9eedbfc9e863 100644
--- a/tools/perf/util/pmu.c
+++ b/tools/perf/util/pmu.c
@@ -494,9 +494,13 @@ static int pmu_aliases_parse(int dirfd, struct list_head *head)
 			continue;
 
 		fd = openat(dirfd, name, O_RDONLY);
+		if (fd == -1) {
+			pr_debug("Cannot open %s\n", name);
+			continue;
+		}
 		file = fdopen(fd, "r");
 		if (!file) {
-			pr_debug("Cannot open %s\n", name);
+			close(fd);
 			continue;
 		}
 
@@ -1882,9 +1886,13 @@ int perf_pmu__caps_parse(struct perf_pmu *pmu)
 			continue;
 
 		fd = openat(caps_fd, name, O_RDONLY);
+		if (fd == -1)
+			continue;
 		file = fdopen(fd, "r");
-		if (!file)
+		if (!file) {
+			close(fd);
 			continue;
+		}
 
 		if (!fgets(value, sizeof(value), file) ||
 		    (perf_pmu__new_caps(&pmu->caps, name, value) < 0)) {
-- 
2.40.0.348.gf938b09366-goog

Re: [PATCH v3 2/2] perf pmu: Fix a few potential fd leaks

[Namhyung Kim]

On Wed, Apr 5, 2023 at 11:53 PM Ian Rogers <irogers@google.com> wrote:
>
> Ensure fd is closed on error paths.
>
> Signed-off-by: Ian Rogers <irogers@google.com>

Acked-by: Namhyung Kim <namhyung@kernel.org>

Thanks,
Namhyung

> ---
>  tools/perf/util/pmu.c | 12 ++++++++++--
>  1 file changed, 10 insertions(+), 2 deletions(-)
>
> diff --git a/tools/perf/util/pmu.c b/tools/perf/util/pmu.c
> index 96ef317bac41..9eedbfc9e863 100644
> --- a/tools/perf/util/pmu.c
> +++ b/tools/perf/util/pmu.c
> @@ -494,9 +494,13 @@ static int pmu_aliases_parse(int dirfd, struct list_head *head)
>                         continue;
>
>                 fd = openat(dirfd, name, O_RDONLY);
> +               if (fd == -1) {
> +                       pr_debug("Cannot open %s\n", name);
> +                       continue;
> +               }
>                 file = fdopen(fd, "r");
>                 if (!file) {
> -                       pr_debug("Cannot open %s\n", name);
> +                       close(fd);
>                         continue;
>                 }
>
> @@ -1882,9 +1886,13 @@ int perf_pmu__caps_parse(struct perf_pmu *pmu)
>                         continue;
>
>                 fd = openat(caps_fd, name, O_RDONLY);
> +               if (fd == -1)
> +                       continue;
>                 file = fdopen(fd, "r");
> -               if (!file)
> +               if (!file) {
> +                       close(fd);
>                         continue;
> +               }
>
>                 if (!fgets(value, sizeof(value), file) ||
>                     (perf_pmu__new_caps(&pmu->caps, name, value) < 0)) {
> --
> 2.40.0.348.gf938b09366-goog
>

Re: [PATCH v3 2/2] perf pmu: Fix a few potential fd leaks

[Arnaldo Carvalho de Melo]

Em Wed, Apr 05, 2023 at 11:52:24PM -0700, Ian Rogers escreveu:
> Ensure fd is closed on error paths.

Was this reported by Jiri?

- Arnaldo
 
> Signed-off-by: Ian Rogers <irogers@google.com>
> ---
>  tools/perf/util/pmu.c | 12 ++++++++++--
>  1 file changed, 10 insertions(+), 2 deletions(-)
> 
> diff --git a/tools/perf/util/pmu.c b/tools/perf/util/pmu.c
> index 96ef317bac41..9eedbfc9e863 100644
> --- a/tools/perf/util/pmu.c
> +++ b/tools/perf/util/pmu.c
> @@ -494,9 +494,13 @@ static int pmu_aliases_parse(int dirfd, struct list_head *head)
>  			continue;
>  
>  		fd = openat(dirfd, name, O_RDONLY);
> +		if (fd == -1) {
> +			pr_debug("Cannot open %s\n", name);
> +			continue;
> +		}
>  		file = fdopen(fd, "r");
>  		if (!file) {
> -			pr_debug("Cannot open %s\n", name);
> +			close(fd);
>  			continue;
>  		}
>  
> @@ -1882,9 +1886,13 @@ int perf_pmu__caps_parse(struct perf_pmu *pmu)
>  			continue;
>  
>  		fd = openat(caps_fd, name, O_RDONLY);
> +		if (fd == -1)
> +			continue;
>  		file = fdopen(fd, "r");
> -		if (!file)
> +		if (!file) {
> +			close(fd);
>  			continue;
> +		}
>  
>  		if (!fgets(value, sizeof(value), file) ||
>  		    (perf_pmu__new_caps(&pmu->caps, name, value) < 0)) {
> -- 
> 2.40.0.348.gf938b09366-goog
> 

-- 

- Arnaldo

Re: [PATCH v3 2/2] perf pmu: Fix a few potential fd leaks

[Ian Rogers]

On Thu, Apr 6, 2023 at 2:09 PM Arnaldo Carvalho de Melo <acme@kernel.org> wrote:
>
> Em Wed, Apr 05, 2023 at 11:52:24PM -0700, Ian Rogers escreveu:
> > Ensure fd is closed on error paths.
>
> Was this reported by Jiri?

Jiri's one was in the code I modified, whereas these were from
Namhyung's previous openat change. It is the same issue, I'm agnostic
on whether it needs a tag or not.

Thanks,
Ian

> - Arnaldo
>
> > Signed-off-by: Ian Rogers <irogers@google.com>
> > ---
> >  tools/perf/util/pmu.c | 12 ++++++++++--
> >  1 file changed, 10 insertions(+), 2 deletions(-)
> >
> > diff --git a/tools/perf/util/pmu.c b/tools/perf/util/pmu.c
> > index 96ef317bac41..9eedbfc9e863 100644
> > --- a/tools/perf/util/pmu.c
> > +++ b/tools/perf/util/pmu.c
> > @@ -494,9 +494,13 @@ static int pmu_aliases_parse(int dirfd, struct list_head *head)
> >                       continue;
> >
> >               fd = openat(dirfd, name, O_RDONLY);
> > +             if (fd == -1) {
> > +                     pr_debug("Cannot open %s\n", name);
> > +                     continue;
> > +             }
> >               file = fdopen(fd, "r");
> >               if (!file) {
> > -                     pr_debug("Cannot open %s\n", name);
> > +                     close(fd);
> >                       continue;
> >               }
> >
> > @@ -1882,9 +1886,13 @@ int perf_pmu__caps_parse(struct perf_pmu *pmu)
> >                       continue;
> >
> >               fd = openat(caps_fd, name, O_RDONLY);
> > +             if (fd == -1)
> > +                     continue;
> >               file = fdopen(fd, "r");
> > -             if (!file)
> > +             if (!file) {
> > +                     close(fd);
> >                       continue;
> > +             }
> >
> >               if (!fgets(value, sizeof(value), file) ||
> >                   (perf_pmu__new_caps(&pmu->caps, name, value) < 0)) {
> > --
> > 2.40.0.348.gf938b09366-goog
> >
>
> --
>
> - Arnaldo

Re: [PATCH v3 1/2] perf pmu: Make parser reentrant

[Jiri Olsa]

On Wed, Apr 05, 2023 at 11:52:23PM -0700, Ian Rogers wrote:
> By default bison uses global state for compatibility with yacc. Make
> the parser reentrant so that it may be used in asynchronous and
> multithreaded situations.
> 
> Signed-off-by: Ian Rogers <irogers@google.com>

Acked-by: Jiri Olsa <jolsa@kernel.org>

jirka

> ---
>  tools/perf/util/pmu.c | 26 ++++++++++++++++++++------
>  tools/perf/util/pmu.h |  2 +-
>  tools/perf/util/pmu.l | 17 ++++++++++++-----
>  tools/perf/util/pmu.y |  5 ++++-
>  4 files changed, 37 insertions(+), 13 deletions(-)
> 
> diff --git a/tools/perf/util/pmu.c b/tools/perf/util/pmu.c
> index 78a407b42ad1..96ef317bac41 100644
> --- a/tools/perf/util/pmu.c
> +++ b/tools/perf/util/pmu.c
> @@ -24,6 +24,8 @@
>  #include "evsel.h"
>  #include "pmu.h"
>  #include "pmus.h"
> +#include "pmu-bison.h"
> +#include "pmu-flex.h"
>  #include "parse-events.h"
>  #include "print-events.h"
>  #include "header.h"
> @@ -57,9 +59,6 @@ struct perf_pmu_format {
>  	struct list_head list;
>  };
>  
> -int perf_pmu_parse(struct list_head *list, char *name);
> -extern FILE *perf_pmu_in;
> -
>  static bool hybrid_scanned;
>  
>  static struct perf_pmu *perf_pmu__find2(int dirfd, const char *name);
> @@ -81,6 +80,8 @@ int perf_pmu__format_parse(int dirfd, struct list_head *head)
>  	while (!ret && (evt_ent = readdir(format_dir))) {
>  		char *name = evt_ent->d_name;
>  		int fd;
> +		void *scanner;
> +		FILE *file;
>  
>  		if (!strcmp(name, ".") || !strcmp(name, ".."))
>  			continue;
> @@ -91,9 +92,22 @@ int perf_pmu__format_parse(int dirfd, struct list_head *head)
>  		if (fd < 0)
>  			break;
>  
> -		perf_pmu_in = fdopen(fd, "r");
> -		ret = perf_pmu_parse(head, name);
> -		fclose(perf_pmu_in);
> +		file = fdopen(fd, "r");
> +		if (!file) {
> +			close(fd);
> +			break;
> +		}
> +
> +		ret = perf_pmu_lex_init(&scanner);
> +		if (ret) {
> +			fclose(file);
> +			break;
> +		}
> +
> +		perf_pmu_set_in(file, scanner);
> +		ret = perf_pmu_parse(head, name, scanner);
> +		perf_pmu_lex_destroy(scanner);
> +		fclose(file);
>  	}
>  
>  	closedir(format_dir);
> diff --git a/tools/perf/util/pmu.h b/tools/perf/util/pmu.h
> index 32c3a75bca0e..d53618c65c92 100644
> --- a/tools/perf/util/pmu.h
> +++ b/tools/perf/util/pmu.h
> @@ -206,7 +206,7 @@ int perf_pmu__check_alias(struct perf_pmu *pmu, struct list_head *head_terms,
>  			  struct perf_pmu_info *info);
>  struct list_head *perf_pmu__alias(struct perf_pmu *pmu,
>  				  struct list_head *head_terms);
> -void perf_pmu_error(struct list_head *list, char *name, char const *msg);
> +void perf_pmu_error(struct list_head *list, char *name, void *scanner, char const *msg);
>  
>  int perf_pmu__new_format(struct list_head *list, char *name,
>  			 int config, unsigned long *bits);
> diff --git a/tools/perf/util/pmu.l b/tools/perf/util/pmu.l
> index 58b4926cfaca..67b247be693b 100644
> --- a/tools/perf/util/pmu.l
> +++ b/tools/perf/util/pmu.l
> @@ -1,4 +1,6 @@
>  %option prefix="perf_pmu_"
> +%option reentrant
> +%option bison-bridge
>  
>  %{
>  #include <stdlib.h>
> @@ -6,16 +8,21 @@
>  #include "pmu.h"
>  #include "pmu-bison.h"
>  
> -static int value(int base)
> +char *perf_pmu_get_text(yyscan_t yyscanner);
> +YYSTYPE *perf_pmu_get_lval(yyscan_t yyscanner);
> +
> +static int value(yyscan_t scanner, int base)
>  {
> +	YYSTYPE *yylval = perf_pmu_get_lval(scanner);
> +	char *text = perf_pmu_get_text(scanner);
>  	long num;
>  
>  	errno = 0;
> -	num = strtoul(perf_pmu_text, NULL, base);
> +	num = strtoul(text, NULL, base);
>  	if (errno)
>  		return PP_ERROR;
>  
> -	perf_pmu_lval.num = num;
> +	yylval->num = num;
>  	return PP_VALUE;
>  }
>  
> @@ -25,7 +32,7 @@ num_dec         [0-9]+
>  
>  %%
>  
> -{num_dec}	{ return value(10); }
> +{num_dec}	{ return value(yyscanner, 10); }
>  config		{ return PP_CONFIG; }
>  -		{ return '-'; }
>  :		{ return ':'; }
> @@ -35,7 +42,7 @@ config		{ return PP_CONFIG; }
>  
>  %%
>  
> -int perf_pmu_wrap(void)
> +int perf_pmu_wrap(void *scanner __maybe_unused)
>  {
>  	return 1;
>  }
> diff --git a/tools/perf/util/pmu.y b/tools/perf/util/pmu.y
> index e675d79a0274..dff4e892ac4d 100644
> --- a/tools/perf/util/pmu.y
> +++ b/tools/perf/util/pmu.y
> @@ -1,6 +1,8 @@
> -
> +%define api.pure full
>  %parse-param {struct list_head *format}
>  %parse-param {char *name}
> +%parse-param {void *scanner}
> +%lex-param {void* scanner}
>  
>  %{
>  
> @@ -78,6 +80,7 @@ PP_VALUE
>  
>  void perf_pmu_error(struct list_head *list __maybe_unused,
>  		    char *name __maybe_unused,
> +		    void *scanner __maybe_unused,
>  		    char const *msg __maybe_unused)
>  {
>  }
> -- 
> 2.40.0.348.gf938b09366-goog
> 

Re: [PATCH v3 2/2] perf pmu: Fix a few potential fd leaks

[Jiri Olsa]

On Wed, Apr 05, 2023 at 11:52:24PM -0700, Ian Rogers wrote:
> Ensure fd is closed on error paths.
> 
> Signed-off-by: Ian Rogers <irogers@google.com>

nice catch

Acked-by: Jiri Olsa <jolsa@kernel.org>

thanks,
jirka

> ---
>  tools/perf/util/pmu.c | 12 ++++++++++--
>  1 file changed, 10 insertions(+), 2 deletions(-)
> 
> diff --git a/tools/perf/util/pmu.c b/tools/perf/util/pmu.c
> index 96ef317bac41..9eedbfc9e863 100644
> --- a/tools/perf/util/pmu.c
> +++ b/tools/perf/util/pmu.c
> @@ -494,9 +494,13 @@ static int pmu_aliases_parse(int dirfd, struct list_head *head)
>  			continue;
>  
>  		fd = openat(dirfd, name, O_RDONLY);
> +		if (fd == -1) {
> +			pr_debug("Cannot open %s\n", name);
> +			continue;
> +		}
>  		file = fdopen(fd, "r");
>  		if (!file) {
> -			pr_debug("Cannot open %s\n", name);
> +			close(fd);
>  			continue;
>  		}
>  
> @@ -1882,9 +1886,13 @@ int perf_pmu__caps_parse(struct perf_pmu *pmu)
>  			continue;
>  
>  		fd = openat(caps_fd, name, O_RDONLY);
> +		if (fd == -1)
> +			continue;
>  		file = fdopen(fd, "r");
> -		if (!file)
> +		if (!file) {
> +			close(fd);
>  			continue;
> +		}
>  
>  		if (!fgets(value, sizeof(value), file) ||
>  		    (perf_pmu__new_caps(&pmu->caps, name, value) < 0)) {
> -- 
> 2.40.0.348.gf938b09366-goog
>