perf script: Use openat for directory iteration

Rewrite the directory iteration to use openat so that large character
arrays aren't needed. The arrays are warned about potential buffer
overflows by GCC when the code exists in a single C file.

Signed-off-by: Ian Rogers <[email protected]>
Tested-by: Arnaldo Carvalho de Melo <[email protected]>
Acked-by: Namhyung Kim <[email protected]>
Cc: Adrian Hunter <[email protected]>
Cc: Alexander Shishkin <[email protected]>
Cc: Andi Kleen <[email protected]>
Cc: Athira Rajeev <[email protected]>
Cc: Colin Ian King <[email protected]>
Cc: Dapeng Mi <[email protected]>
Cc: Howard Chu <[email protected]>
Cc: Ilya Leoshkevich <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: James Clark <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Josh Poimboeuf <[email protected]>
Cc: Kan Liang <[email protected]>
Cc: Mark Rutland <[email protected]>
Cc: Michael Petlan <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Thomas Richter <[email protected]>
Cc: Veronika Molnarova <[email protected]>
Cc: Weilin Wang <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>

1 files changed, 60 insertions, 27 deletions

diff --git a/tools/perf/builtin-script.c b/tools/perf/builtin-script.c
index cc42b472dfff..196e2f3438c5 100644
--- a/tools/perf/builtin-script.c
+++ b/tools/perf/builtin-script.c
@@ -3535,27 +3535,35 @@ static void free_dlarg(void)
  * which is covered well now. And new parsing code should be added to
  * cover the future complex formats like event groups etc.
  */
-static int check_ev_match(char *dir_name, char *scriptname,
-			struct perf_session *session)
+static int check_ev_match(int dir_fd, const char *scriptname, struct perf_session *session)
 {
-	char filename[MAXPATHLEN], evname[128];
-	char line[BUFSIZ], *p;
-	struct evsel *pos;
-	int match, len;
+	char line[BUFSIZ];
 	FILE *fp;
 
-	scnprintf(filename, MAXPATHLEN, "%s/bin/%s-record", dir_name, scriptname);
+	{
+		char filename[FILENAME_MAX + 5];
+		int fd;
 
-	fp = fopen(filename, "r");
-	if (!fp)
-		return -1;
+		scnprintf(filename, sizeof(filename), "bin/%s-record", scriptname);
+		fd = openat(dir_fd, filename, O_RDONLY);
+		if (fd == -1)
+			return -1;
+		fp = fdopen(fd, "r");
+		if (!fp)
+			return -1;
+	}
 
 	while (fgets(line, sizeof(line), fp)) {
-		p = skip_spaces(line);
+		char *p = skip_spaces(line);
+
 		if (*p == '#')
 			continue;
 
 		while (strlen(p)) {
+			int match, len;
+			struct evsel *pos;
+			char evname[128];
+
 			p = strstr(p, "-e");
 			if (!p)
 				break;
@@ -3598,7 +3606,7 @@ int find_scripts(char **scripts_array, char **scripts_path_array, int num,
 		 int pathlen)
 {
 	struct dirent *script_dirent, *lang_dirent;
-	char scripts_path[MAXPATHLEN], lang_path[MAXPATHLEN];
+	int scripts_dir_fd, lang_dir_fd;
 	DIR *scripts_dir, *lang_dir;
 	struct perf_session *session;
 	struct perf_data data = {
@@ -3607,51 +3615,76 @@ int find_scripts(char **scripts_array, char **scripts_path_array, int num,
 	};
 	char *temp;
 	int i = 0;
+	const char *exec_path = get_argv_exec_path();
 
 	session = perf_session__new(&data, NULL);
 	if (IS_ERR(session))
 		return PTR_ERR(session);
 
-	snprintf(scripts_path, MAXPATHLEN, "%s/scripts", get_argv_exec_path());
+	{
+		char scripts_path[PATH_MAX];
 
-	scripts_dir = opendir(scripts_path);
+		snprintf(scripts_path, sizeof(scripts_path), "%s/scripts", exec_path);
+		scripts_dir_fd = open(scripts_path, O_DIRECTORY);
+		pr_err("Failed to open directory '%s'", scripts_path);
+		if (scripts_dir_fd == -1) {
+			perf_session__delete(session);
+			return -1;
+		}
+	}
+	scripts_dir = fdopendir(scripts_dir_fd);
 	if (!scripts_dir) {
+		close(scripts_dir_fd);
 		perf_session__delete(session);
 		return -1;
 	}
 
-	for_each_lang(scripts_path, scripts_dir, lang_dirent) {
-		scnprintf(lang_path, MAXPATHLEN, "%s/%s", scripts_path,
-			  lang_dirent->d_name);
+	while ((lang_dirent = readdir(scripts_dir)) != NULL) {
+		if (lang_dirent->d_type != DT_DIR &&
+		    (lang_dirent->d_type == DT_UNKNOWN &&
+		     !is_directory_at(scripts_dir_fd, lang_dirent->d_name)))
+			continue;
+		if (!strcmp(lang_dirent->d_name, ".") || !strcmp(lang_dirent->d_name, ".."))
+			continue;
+
 #ifndef HAVE_LIBPERL_SUPPORT
-		if (strstr(lang_path, "perl"))
+		if (strstr(lang_dirent->d_name, "perl"))
 			continue;
 #endif
 #ifndef HAVE_LIBPYTHON_SUPPORT
-		if (strstr(lang_path, "python"))
+		if (strstr(lang_dirent->d_name, "python"))
 			continue;
 #endif
 
-		lang_dir = opendir(lang_path);
-		if (!lang_dir)
+		lang_dir_fd = openat(scripts_dir_fd, lang_dirent->d_name, O_DIRECTORY);
+		if (lang_dir_fd == -1)
 			continue;
-
-		for_each_script(lang_path, lang_dir, script_dirent) {
+		lang_dir = fdopendir(lang_dir_fd);
+		if (!lang_dir) {
+			close(lang_dir_fd);
+			continue;
+		}
+		while ((script_dirent = readdir(lang_dir)) != NULL) {
+			if (script_dirent->d_type == DT_DIR)
+				continue;
+			if (script_dirent->d_type == DT_UNKNOWN &&
+			    is_directory_at(lang_dir_fd, script_dirent->d_name))
+				continue;
 			/* Skip those real time scripts: xxxtop.p[yl] */
 			if (strstr(script_dirent->d_name, "top."))
 				continue;
 			if (i >= num)
 				break;
-			snprintf(scripts_path_array[i], pathlen, "%s/%s",
-				lang_path,
+			scnprintf(scripts_path_array[i], pathlen, "%s/scripts/%s/%s",
+				exec_path,
+				lang_dirent->d_name,
 				script_dirent->d_name);
 			temp = strchr(script_dirent->d_name, '.');
 			snprintf(scripts_array[i],
 				(temp - script_dirent->d_name) + 1,
 				"%s", script_dirent->d_name);
 
-			if (check_ev_match(lang_path,
-					scripts_array[i], session))
+			if (check_ev_match(lang_dir_fd, scripts_array[i], session))
 				continue;
 
 			i++;