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

From: Namhyung Kim
Date: Fri Mar 31 2023 - 16:30:02 EST


Signed-off-by: Namhyung Kim <namhyung@xxxxxxxxxx>
---
tools/perf/util/print-events.c | 26 ++++++++++++++++++++------
1 file changed, 20 insertions(+), 6 deletions(-)

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