diff mbox series

[1/9] perf list: Use relative path for tracepoint scan

Message ID 20230331202949.810326-2-namhyung@kernel.org
State New
Headers
Series perf tools: Update pmu scan using openat() (v1) |

Commit Message

Namhyung Kim March 31, 2023, 8:29 p.m. UTC 
  Signed-off-by: Namhyung Kim <namhyung@kernel.org>
---
 tools/perf/util/print-events.c | 26 ++++++++++++++++++++------
 1 file changed, 20 insertions(+), 6 deletions(-)

Comments

Arnaldo Carvalho de Melo April 3, 2023, 9:59 p.m. UTC | #1 
Em Fri, Mar 31, 2023 at 01:29:41PM -0700, Namhyung Kim escreveu:
> Signed-off-by: Namhyung Kim <namhyung@kernel.org>
> ---
>  tools/perf/util/print-events.c | 26 ++++++++++++++++++++------
>  1 file changed, 20 insertions(+), 6 deletions(-)

Add to add this to fix on Alma Linux 8, and scandirat isn't being found
on musl libc (Alpine Linux), probably we'll need some scaffolding...

- Arnaldo


diff --git a/tools/perf/util/print-events.c b/tools/perf/util/print-events.c
index 26a7e017c9284c01..28aa0b9300253d0a 100644
--- a/tools/perf/util/print-events.c
+++ b/tools/perf/util/print-events.c
@@ -6,6 +6,7 @@
 #include <string.h>
 #include <fcntl.h>
 #include <sys/param.h>
+#include <unistd.h>
 
 #include <api/fs/tracing_path.h>
 #include <linux/stddef.h>
 
> diff --git a/tools/perf/util/print-events.c b/tools/perf/util/print-events.c
> index 62e9ea7dcf40..26a7e017c928 100644
> --- a/tools/perf/util/print-events.c
> +++ b/tools/perf/util/print-events.c
> @@ -4,6 +4,7 @@
>  #include <stdio.h>
>  #include <stdlib.h>
>  #include <string.h>
> +#include <fcntl.h>
>  #include <sys/param.h>
>  
>  #include <api/fs/tracing_path.h>
> @@ -59,12 +60,20 @@ static const struct event_symbol event_symbols_tool[PERF_TOOL_MAX] = {
>  void print_tracepoint_events(const struct print_callbacks *print_cb, void *print_state)
>  {
>  	struct dirent **sys_namelist = NULL;
> +	char *events_path = get_tracing_file("events");
>  	int sys_items = tracing_events__scandir_alphasort(&sys_namelist);
> +	int events_fd = open(events_path, O_PATH);
> +
> +	put_tracing_file(events_path);
> +	if (events_fd < 0) {
> +		printf("Error: failed to open tracing events directory\n");
> +		return;
> +	}
>  
>  	for (int i = 0; i < sys_items; i++) {
>  		struct dirent *sys_dirent = sys_namelist[i];
>  		struct dirent **evt_namelist = NULL;
> -		char *dir_path;
> +		int dir_fd;
>  		int evt_items;
>  
>  		if (sys_dirent->d_type != DT_DIR ||
> @@ -72,22 +81,26 @@ void print_tracepoint_events(const struct print_callbacks *print_cb, void *print
>  		    !strcmp(sys_dirent->d_name, ".."))
>  			continue;
>  
> -		dir_path = get_events_file(sys_dirent->d_name);
> -		if (!dir_path)
> +		dir_fd = openat(events_fd, sys_dirent->d_name, O_PATH);
> +		if (dir_fd < 0)
>  			continue;
>  
> -		evt_items = scandir(dir_path, &evt_namelist, NULL, alphasort);
> +		evt_items = scandirat(events_fd, sys_dirent->d_name, &evt_namelist, NULL, alphasort);
>  		for (int j = 0; j < evt_items; j++) {
>  			struct dirent *evt_dirent = evt_namelist[j];
>  			char evt_path[MAXPATHLEN];
> +			int evt_fd;
>  
>  			if (evt_dirent->d_type != DT_DIR ||
>  			    !strcmp(evt_dirent->d_name, ".") ||
>  			    !strcmp(evt_dirent->d_name, ".."))
>  				continue;
>  
> -			if (tp_event_has_id(dir_path, evt_dirent) != 0)
> +			snprintf(evt_path, sizeof(evt_path), "%s/id", evt_dirent->d_name);
> +			evt_fd = openat(dir_fd, evt_path, O_RDONLY);
> +			if (evt_fd < 0)
>  				continue;
> +			close(evt_fd);
>  
>  			snprintf(evt_path, MAXPATHLEN, "%s:%s",
>  				 sys_dirent->d_name, evt_dirent->d_name);
> @@ -103,10 +116,11 @@ void print_tracepoint_events(const struct print_callbacks *print_cb, void *print
>  					/*long_desc=*/NULL,
>  					/*encoding_desc=*/NULL);
>  		}
> -		free(dir_path);
> +		close(dir_fd);
>  		free(evt_namelist);
>  	}
>  	free(sys_namelist);
> +	close(events_fd);
>  }
>  
>  void print_sdt_events(const struct print_callbacks *print_cb, void *print_state)
> -- 
> 2.40.0.348.gf938b09366-goog
>
Arnaldo Carvalho de Melo April 3, 2023, 10 p.m. UTC | #2 
Em Mon, Apr 03, 2023 at 06:59:10PM -0300, Arnaldo Carvalho de Melo escreveu:
> Em Fri, Mar 31, 2023 at 01:29:41PM -0700, Namhyung Kim escreveu:
> > Signed-off-by: Namhyung Kim <namhyung@kernel.org>
> > ---
> >  tools/perf/util/print-events.c | 26 ++++++++++++++++++++------
> >  1 file changed, 20 insertions(+), 6 deletions(-)
> 
> Add to add this to fix on Alma Linux 8, and scandirat isn't being found
> on musl libc (Alpine Linux), probably we'll need some scaffolding...

Some discussion about this for some other project:

https://gitlab.com/apparmor/apparmor/-/merge_requests/107
 
> - Arnaldo
> 
> 
> diff --git a/tools/perf/util/print-events.c b/tools/perf/util/print-events.c
> index 26a7e017c9284c01..28aa0b9300253d0a 100644
> --- a/tools/perf/util/print-events.c
> +++ b/tools/perf/util/print-events.c
> @@ -6,6 +6,7 @@
>  #include <string.h>
>  #include <fcntl.h>
>  #include <sys/param.h>
> +#include <unistd.h>
>  
>  #include <api/fs/tracing_path.h>
>  #include <linux/stddef.h>
>  
> > diff --git a/tools/perf/util/print-events.c b/tools/perf/util/print-events.c
> > index 62e9ea7dcf40..26a7e017c928 100644
> > --- a/tools/perf/util/print-events.c
> > +++ b/tools/perf/util/print-events.c
> > @@ -4,6 +4,7 @@
> >  #include <stdio.h>
> >  #include <stdlib.h>
> >  #include <string.h>
> > +#include <fcntl.h>
> >  #include <sys/param.h>
> >  
> >  #include <api/fs/tracing_path.h>
> > @@ -59,12 +60,20 @@ static const struct event_symbol event_symbols_tool[PERF_TOOL_MAX] = {
> >  void print_tracepoint_events(const struct print_callbacks *print_cb, void *print_state)
> >  {
> >  	struct dirent **sys_namelist = NULL;
> > +	char *events_path = get_tracing_file("events");
> >  	int sys_items = tracing_events__scandir_alphasort(&sys_namelist);
> > +	int events_fd = open(events_path, O_PATH);
> > +
> > +	put_tracing_file(events_path);
> > +	if (events_fd < 0) {
> > +		printf("Error: failed to open tracing events directory\n");
> > +		return;
> > +	}
> >  
> >  	for (int i = 0; i < sys_items; i++) {
> >  		struct dirent *sys_dirent = sys_namelist[i];
> >  		struct dirent **evt_namelist = NULL;
> > -		char *dir_path;
> > +		int dir_fd;
> >  		int evt_items;
> >  
> >  		if (sys_dirent->d_type != DT_DIR ||
> > @@ -72,22 +81,26 @@ void print_tracepoint_events(const struct print_callbacks *print_cb, void *print
> >  		    !strcmp(sys_dirent->d_name, ".."))
> >  			continue;
> >  
> > -		dir_path = get_events_file(sys_dirent->d_name);
> > -		if (!dir_path)
> > +		dir_fd = openat(events_fd, sys_dirent->d_name, O_PATH);
> > +		if (dir_fd < 0)
> >  			continue;
> >  
> > -		evt_items = scandir(dir_path, &evt_namelist, NULL, alphasort);
> > +		evt_items = scandirat(events_fd, sys_dirent->d_name, &evt_namelist, NULL, alphasort);
> >  		for (int j = 0; j < evt_items; j++) {
> >  			struct dirent *evt_dirent = evt_namelist[j];
> >  			char evt_path[MAXPATHLEN];
> > +			int evt_fd;
> >  
> >  			if (evt_dirent->d_type != DT_DIR ||
> >  			    !strcmp(evt_dirent->d_name, ".") ||
> >  			    !strcmp(evt_dirent->d_name, ".."))
> >  				continue;
> >  
> > -			if (tp_event_has_id(dir_path, evt_dirent) != 0)
> > +			snprintf(evt_path, sizeof(evt_path), "%s/id", evt_dirent->d_name);
> > +			evt_fd = openat(dir_fd, evt_path, O_RDONLY);
> > +			if (evt_fd < 0)
> >  				continue;
> > +			close(evt_fd);
> >  
> >  			snprintf(evt_path, MAXPATHLEN, "%s:%s",
> >  				 sys_dirent->d_name, evt_dirent->d_name);
> > @@ -103,10 +116,11 @@ void print_tracepoint_events(const struct print_callbacks *print_cb, void *print
> >  					/*long_desc=*/NULL,
> >  					/*encoding_desc=*/NULL);
> >  		}
> > -		free(dir_path);
> > +		close(dir_fd);
> >  		free(evt_namelist);
> >  	}
> >  	free(sys_namelist);
> > +	close(events_fd);
> >  }
> >  
> >  void print_sdt_events(const struct print_callbacks *print_cb, void *print_state)
> > -- 
> > 2.40.0.348.gf938b09366-goog
> > 
> 
> -- 
> 
> - Arnaldo
Arnaldo Carvalho de Melo April 4, 2023, 2:10 p.m. UTC | #3 
Em Mon, Apr 03, 2023 at 06:59:10PM -0300, Arnaldo Carvalho de Melo escreveu:
> Em Fri, Mar 31, 2023 at 01:29:41PM -0700, Namhyung Kim escreveu:
> > Signed-off-by: Namhyung Kim <namhyung@kernel.org>
> > ---
> >  tools/perf/util/print-events.c | 26 ++++++++++++++++++++------
> >  1 file changed, 20 insertions(+), 6 deletions(-)
> 
> Add to add this to fix on Alma Linux 8, and scandirat isn't being found
> on musl libc (Alpine Linux), probably we'll need some scaffolding...

About scandirat I'm adding the feature test below and this patch to the
patch that starts using scandirat():

diff --git a/tools/perf/util/print-events.c b/tools/perf/util/print-events.c
index 28aa0b9300253d0a..386b1ab0b60e1d93 100644
--- a/tools/perf/util/print-events.c
+++ b/tools/perf/util/print-events.c
@@ -58,11 +58,9 @@ static const struct event_symbol event_symbols_tool[PERF_TOOL_MAX] = {
 /*
  * Print the events from <debugfs_mount_point>/tracing/events
  */
-void print_tracepoint_events(const struct print_callbacks *print_cb, void *print_state)
+void print_tracepoint_events(const struct print_callbacks *print_cb __maybe_unused, void *print_state __maybe_unused)
 {
-	struct dirent **sys_namelist = NULL;
 	char *events_path = get_tracing_file("events");
-	int sys_items = tracing_events__scandir_alphasort(&sys_namelist);
 	int events_fd = open(events_path, O_PATH);
 
 	put_tracing_file(events_path);
@@ -71,6 +69,11 @@ void print_tracepoint_events(const struct print_callbacks *print_cb, void *print
 		return;
 	}
 
+#ifdef HAVE_SCANDIRAT_SUPPORT
+{
+	struct dirent **sys_namelist = NULL;
+	int sys_items = tracing_events__scandir_alphasort(&sys_namelist);
+
 	for (int i = 0; i < sys_items; i++) {
 		struct dirent *sys_dirent = sys_namelist[i];
 		struct dirent **evt_namelist = NULL;
@@ -120,7 +123,13 @@ void print_tracepoint_events(const struct print_callbacks *print_cb, void *print
 		close(dir_fd);
 		free(evt_namelist);
 	}
+
 	free(sys_namelist);
+}
+#else
+	printf("\nWARNING: Your libc doesn't have the scandir function, please ask its maintainers to implement it.\n"
+	       "         As a rough fallback, please do 'ls %s' to see the available tracepoint events.\n", events_path);
+#endif
 	close(events_fd);
 }
 

From b25f9de2f944a550b063322b7210f4392e622a5e Mon Sep 17 00:00:00 2001
From: Arnaldo Carvalho de Melo <acme@redhat.com>
Date: Tue, 4 Apr 2023 11:05:57 -0300
Subject: [PATCH 1/1] tools build: Add a feature test for scandirat(), that is
 not implemented so far in musl and uclibc

We use it just when listing tracepoint events, and for root, so just
emit a warning about it to get users to ask the library maintainers to
implement it, as suggested in this systemd ticket:

 https://github.com/systemd/casync/issues/129

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
 tools/build/Makefile.feature   | 1 +
 tools/build/feature/Makefile   | 4 ++++
 tools/build/feature/test-all.c | 5 +++++
 tools/perf/Makefile.config     | 4 ++++
 4 files changed, 14 insertions(+)

diff --git a/tools/build/Makefile.feature b/tools/build/Makefile.feature
index 214622d7537cc56b..934e2777a2dbcd90 100644
--- a/tools/build/Makefile.feature
+++ b/tools/build/Makefile.feature
@@ -64,6 +64,7 @@ FEATURE_TESTS_BASIC :=                  \
         lzma                            \
         get_cpuid                       \
         bpf                             \
+        scandirat			\
         sched_getcpu			\
         sdt				\
         setns				\
diff --git a/tools/build/feature/Makefile b/tools/build/feature/Makefile
index 0a3b9281f8b08000..0f0aa9b7d7b5e43c 100644
--- a/tools/build/feature/Makefile
+++ b/tools/build/feature/Makefile
@@ -65,6 +65,7 @@ FILES=                                          \
          test-gettid.bin			\
          test-jvmti.bin				\
          test-jvmti-cmlr.bin			\
+         test-scandirat.bin			\
          test-sched_getcpu.bin			\
          test-setns.bin				\
          test-libopencsd.bin			\
@@ -129,6 +130,9 @@ $(OUTPUT)test-get_current_dir_name.bin:
 $(OUTPUT)test-glibc.bin:
 	$(BUILD)
 
+$(OUTPUT)test-scandirat.bin:
+	$(BUILD)
+
 $(OUTPUT)test-sched_getcpu.bin:
 	$(BUILD)
 
diff --git a/tools/build/feature/test-all.c b/tools/build/feature/test-all.c
index 957c02c7b163b579..6f4bf386a3b5c4b0 100644
--- a/tools/build/feature/test-all.c
+++ b/tools/build/feature/test-all.c
@@ -114,6 +114,10 @@
 # include "test-pthread-barrier.c"
 #undef main
 
+#define main main_test_scandirat
+# include "test-scandirat.c"
+#undef main
+
 #define main main_test_sched_getcpu
 # include "test-sched_getcpu.c"
 #undef main
@@ -206,6 +210,7 @@ int main(int argc, char *argv[])
 	main_test_get_cpuid();
 	main_test_bpf();
 	main_test_libcrypto();
+	main_test_scandirat();
 	main_test_sched_getcpu();
 	main_test_sdt();
 	main_test_setns();
diff --git a/tools/perf/Makefile.config b/tools/perf/Makefile.config
index dd203f0a2b7e64e1..16bea51f0bcd95ea 100644
--- a/tools/perf/Makefile.config
+++ b/tools/perf/Makefile.config
@@ -478,6 +478,10 @@ ifdef NO_DWARF
   NO_LIBDW_DWARF_UNWIND := 1
 endif
 
+ifeq ($(feature-scandirat), 1)
+  CFLAGS += -DHAVE_SCANDIRAT_SUPPORT
+endif
+
 ifeq ($(feature-sched_getcpu), 1)
   CFLAGS += -DHAVE_SCHED_GETCPU_SUPPORT
 endif
Namhyung Kim April 4, 2023, 10:08 p.m. UTC | #4 
Hi Arnaldo,

On Tue, Apr 4, 2023 at 7:10 AM Arnaldo Carvalho de Melo <acme@kernel.org> wrote:
>
> Em Mon, Apr 03, 2023 at 06:59:10PM -0300, Arnaldo Carvalho de Melo escreveu:
> > Em Fri, Mar 31, 2023 at 01:29:41PM -0700, Namhyung Kim escreveu:
> > > Signed-off-by: Namhyung Kim <namhyung@kernel.org>
> > > ---
> > >  tools/perf/util/print-events.c | 26 ++++++++++++++++++++------
> > >  1 file changed, 20 insertions(+), 6 deletions(-)
> >
> > Add to add this to fix on Alma Linux 8, and scandirat isn't being found
> > on musl libc (Alpine Linux), probably we'll need some scaffolding...
>
> About scandirat I'm adding the feature test below and this patch to the
> patch that starts using scandirat():

Thanks for doing this!

>
> diff --git a/tools/perf/util/print-events.c b/tools/perf/util/print-events.c
> index 28aa0b9300253d0a..386b1ab0b60e1d93 100644
> --- a/tools/perf/util/print-events.c
> +++ b/tools/perf/util/print-events.c
> @@ -58,11 +58,9 @@ static const struct event_symbol event_symbols_tool[PERF_TOOL_MAX] = {
>  /*
>   * Print the events from <debugfs_mount_point>/tracing/events
>   */
> -void print_tracepoint_events(const struct print_callbacks *print_cb, void *print_state)
> +void print_tracepoint_events(const struct print_callbacks *print_cb __maybe_unused, void *print_state __maybe_unused)
>  {
> -       struct dirent **sys_namelist = NULL;
>         char *events_path = get_tracing_file("events");
> -       int sys_items = tracing_events__scandir_alphasort(&sys_namelist);
>         int events_fd = open(events_path, O_PATH);
>
>         put_tracing_file(events_path);
> @@ -71,6 +69,11 @@ void print_tracepoint_events(const struct print_callbacks *print_cb, void *print
>                 return;
>         }
>
> +#ifdef HAVE_SCANDIRAT_SUPPORT
> +{
> +       struct dirent **sys_namelist = NULL;
> +       int sys_items = tracing_events__scandir_alphasort(&sys_namelist);
> +
>         for (int i = 0; i < sys_items; i++) {
>                 struct dirent *sys_dirent = sys_namelist[i];
>                 struct dirent **evt_namelist = NULL;
> @@ -120,7 +123,13 @@ void print_tracepoint_events(const struct print_callbacks *print_cb, void *print
>                 close(dir_fd);
>                 free(evt_namelist);
>         }
> +
>         free(sys_namelist);
> +}
> +#else
> +       printf("\nWARNING: Your libc doesn't have the scandir function, please ask its maintainers to implement it.\n"
> +              "         As a rough fallback, please do 'ls %s' to see the available tracepoint events.\n", events_path);
> +#endif
>         close(events_fd);
>  }
>
>
> From b25f9de2f944a550b063322b7210f4392e622a5e Mon Sep 17 00:00:00 2001
> From: Arnaldo Carvalho de Melo <acme@redhat.com>
> Date: Tue, 4 Apr 2023 11:05:57 -0300
> Subject: [PATCH 1/1] tools build: Add a feature test for scandirat(), that is
>  not implemented so far in musl and uclibc
>
> We use it just when listing tracepoint events, and for root, so just
> emit a warning about it to get users to ask the library maintainers to
> implement it, as suggested in this systemd ticket:
>
>  https://github.com/systemd/casync/issues/129
>
> Cc: Adrian Hunter <adrian.hunter@intel.com>
> Cc: Ian Rogers <irogers@google.com>
> Cc: Jiri Olsa <jolsa@kernel.org>
> Cc: Namhyung Kim <namhyung@kernel.org>
> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
> ---
>  tools/build/Makefile.feature   | 1 +
>  tools/build/feature/Makefile   | 4 ++++
>  tools/build/feature/test-all.c | 5 +++++
>  tools/perf/Makefile.config     | 4 ++++

Maybe you forgot to add the tools/build/feature/test-scandirat.c :)

Thanks,
Namhyung


>  4 files changed, 14 insertions(+)
>
> diff --git a/tools/build/Makefile.feature b/tools/build/Makefile.feature
> index 214622d7537cc56b..934e2777a2dbcd90 100644
> --- a/tools/build/Makefile.feature
> +++ b/tools/build/Makefile.feature
> @@ -64,6 +64,7 @@ FEATURE_TESTS_BASIC :=                  \
>          lzma                            \
>          get_cpuid                       \
>          bpf                             \
> +        scandirat                      \
>          sched_getcpu                   \
>          sdt                            \
>          setns                          \
> diff --git a/tools/build/feature/Makefile b/tools/build/feature/Makefile
> index 0a3b9281f8b08000..0f0aa9b7d7b5e43c 100644
> --- a/tools/build/feature/Makefile
> +++ b/tools/build/feature/Makefile
> @@ -65,6 +65,7 @@ FILES=                                          \
>           test-gettid.bin                       \
>           test-jvmti.bin                                \
>           test-jvmti-cmlr.bin                   \
> +         test-scandirat.bin                    \
>           test-sched_getcpu.bin                 \
>           test-setns.bin                                \
>           test-libopencsd.bin                   \
> @@ -129,6 +130,9 @@ $(OUTPUT)test-get_current_dir_name.bin:
>  $(OUTPUT)test-glibc.bin:
>         $(BUILD)
>
> +$(OUTPUT)test-scandirat.bin:
> +       $(BUILD)
> +
>  $(OUTPUT)test-sched_getcpu.bin:
>         $(BUILD)
>
> diff --git a/tools/build/feature/test-all.c b/tools/build/feature/test-all.c
> index 957c02c7b163b579..6f4bf386a3b5c4b0 100644
> --- a/tools/build/feature/test-all.c
> +++ b/tools/build/feature/test-all.c
> @@ -114,6 +114,10 @@
>  # include "test-pthread-barrier.c"
>  #undef main
>
> +#define main main_test_scandirat
> +# include "test-scandirat.c"
> +#undef main
> +
>  #define main main_test_sched_getcpu
>  # include "test-sched_getcpu.c"
>  #undef main
> @@ -206,6 +210,7 @@ int main(int argc, char *argv[])
>         main_test_get_cpuid();
>         main_test_bpf();
>         main_test_libcrypto();
> +       main_test_scandirat();
>         main_test_sched_getcpu();
>         main_test_sdt();
>         main_test_setns();
> diff --git a/tools/perf/Makefile.config b/tools/perf/Makefile.config
> index dd203f0a2b7e64e1..16bea51f0bcd95ea 100644
> --- a/tools/perf/Makefile.config
> +++ b/tools/perf/Makefile.config
> @@ -478,6 +478,10 @@ ifdef NO_DWARF
>    NO_LIBDW_DWARF_UNWIND := 1
>  endif
>
> +ifeq ($(feature-scandirat), 1)
> +  CFLAGS += -DHAVE_SCANDIRAT_SUPPORT
> +endif
> +
>  ifeq ($(feature-sched_getcpu), 1)
>    CFLAGS += -DHAVE_SCHED_GETCPU_SUPPORT
>  endif
> --
> 2.39.2
>
Arnaldo Carvalho de Melo April 4, 2023, 10:19 p.m. UTC | #5 
On April 4, 2023 7:08:31 PM GMT-03:00, Namhyung Kim <namhyung@kernel.org> wrote:

>> ---
>>  tools/build/Makefile.feature   | 1 +
>>  tools/build/feature/Makefile   | 4 ++++
>>  tools/build/feature/test-all.c | 5 +++++
>>  tools/perf/Makefile.config     | 4 ++++
>
>Maybe you forgot to add the tools/build/feature/test-scandirat.c :)


Yeah , I noticed that and fixed it:

https://git.kernel.org/pub/scm/linux/kernel/git/acme/linux.git/tree/tools/build/feature/test-scandirat.c?h=tmp.perf-tools-next

- Arnaldo
diff mbox series

Patch

diff --git a/tools/perf/util/print-events.c b/tools/perf/util/print-events.c
index 62e9ea7dcf40..26a7e017c928 100644
--- a/tools/perf/util/print-events.c
+++ b/tools/perf/util/print-events.c
@@ -4,6 +4,7 @@ 
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
+#include <fcntl.h>
 #include <sys/param.h>
 
 #include <api/fs/tracing_path.h>
@@ -59,12 +60,20 @@  static const struct event_symbol event_symbols_tool[PERF_TOOL_MAX] = {
 void print_tracepoint_events(const struct print_callbacks *print_cb, void *print_state)
 {
 	struct dirent **sys_namelist = NULL;
+	char *events_path = get_tracing_file("events");
 	int sys_items = tracing_events__scandir_alphasort(&sys_namelist);
+	int events_fd = open(events_path, O_PATH);
+
+	put_tracing_file(events_path);
+	if (events_fd < 0) {
+		printf("Error: failed to open tracing events directory\n");
+		return;
+	}
 
 	for (int i = 0; i < sys_items; i++) {
 		struct dirent *sys_dirent = sys_namelist[i];
 		struct dirent **evt_namelist = NULL;
-		char *dir_path;
+		int dir_fd;
 		int evt_items;
 
 		if (sys_dirent->d_type != DT_DIR ||
@@ -72,22 +81,26 @@  void print_tracepoint_events(const struct print_callbacks *print_cb, void *print
 		    !strcmp(sys_dirent->d_name, ".."))
 			continue;
 
-		dir_path = get_events_file(sys_dirent->d_name);
-		if (!dir_path)
+		dir_fd = openat(events_fd, sys_dirent->d_name, O_PATH);
+		if (dir_fd < 0)
 			continue;
 
-		evt_items = scandir(dir_path, &evt_namelist, NULL, alphasort);
+		evt_items = scandirat(events_fd, sys_dirent->d_name, &evt_namelist, NULL, alphasort);
 		for (int j = 0; j < evt_items; j++) {
 			struct dirent *evt_dirent = evt_namelist[j];
 			char evt_path[MAXPATHLEN];
+			int evt_fd;
 
 			if (evt_dirent->d_type != DT_DIR ||
 			    !strcmp(evt_dirent->d_name, ".") ||
 			    !strcmp(evt_dirent->d_name, ".."))
 				continue;
 
-			if (tp_event_has_id(dir_path, evt_dirent) != 0)
+			snprintf(evt_path, sizeof(evt_path), "%s/id", evt_dirent->d_name);
+			evt_fd = openat(dir_fd, evt_path, O_RDONLY);
+			if (evt_fd < 0)
 				continue;
+			close(evt_fd);
 
 			snprintf(evt_path, MAXPATHLEN, "%s:%s",
 				 sys_dirent->d_name, evt_dirent->d_name);
@@ -103,10 +116,11 @@  void print_tracepoint_events(const struct print_callbacks *print_cb, void *print
 					/*long_desc=*/NULL,
 					/*encoding_desc=*/NULL);
 		}
-		free(dir_path);
+		close(dir_fd);
 		free(evt_namelist);
 	}
 	free(sys_namelist);
+	close(events_fd);
 }
 
 void print_sdt_events(const struct print_callbacks *print_cb, void *print_state)