linux/tools/perf/util/tracepoint.c
Ian Rogers d790ead8a6 perf tracepoint: Don't scan all tracepoints to test if one exists
In is_valid_tracepoint, rather than scanning
"/sys/kernel/tracing/events/*/*" skipping any path where
"/sys/kernel/tracing/events/*/*/id" doesn't exist, and then testing if
"*:*" matches the tracepoint name, just use the given tracepoint name
replace the ':' with '/' and see if the id file exists.

This turns a nested directory search into a single file available test.

Rather than return 1 for valid and 0 for invalid, return true and false.

Signed-off-by: Ian Rogers <irogers@google.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/20240509153245.1990426-1-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2024-05-09 18:46:43 -03:00

53 lines
1.1 KiB
C

// SPDX-License-Identifier: GPL-2.0
#include "tracepoint.h"
#include <errno.h>
#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <sys/param.h>
#include <unistd.h>
#include <api/fs/tracing_path.h>
#include "fncache.h"
int tp_event_has_id(const char *dir_path, struct dirent *evt_dir)
{
char evt_path[MAXPATHLEN];
int fd;
snprintf(evt_path, MAXPATHLEN, "%s/%s/id", dir_path, evt_dir->d_name);
fd = open(evt_path, O_RDONLY);
if (fd < 0)
return -EINVAL;
close(fd);
return 0;
}
/*
* Check whether event is in <debugfs_mount_point>/tracing/events
*/
bool is_valid_tracepoint(const char *event_string)
{
char *dst, *path = malloc(strlen(event_string) + 4); /* Space for "/id\0". */
bool have_file = false; /* Conservatively return false if memory allocation failed. */
const char *src;
if (!path)
return false;
/* Copy event_string replacing the ':' with '/'. */
for (src = event_string, dst = path; *src; src++, dst++)
*dst = (*src == ':') ? '/' : *src;
/* Add "/id\0". */
memcpy(dst, "/id", 4);
dst = get_events_file(path);
if (dst)
have_file = file_available(dst);
free(dst);
free(path);
return have_file;
}