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 <irogers@google.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Athira Rajeev <atrajeev@linux.vnet.ibm.com>
Cc: Colin Ian King <colin.i.king@gmail.com>
Cc: Dapeng Mi <dapeng1.mi@linux.intel.com>
Cc: Howard Chu <howardchu95@gmail.com>
Cc: Ilya Leoshkevich <iii@linux.ibm.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Clark <james.clark@linaro.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Michael Petlan <mpetlan@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Richter <tmricht@linux.ibm.com>
Cc: Veronika Molnarova <vmolnaro@redhat.com>
Cc: Weilin Wang <weilin.wang@intel.com>
Link: https://lore.kernel.org/r/20241119011644.971342-7-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

diff --git a/tools/perf/builtin-script.c b/tools/perf/builtin-script.c
index cc42b472dfffb2e4bd71763443f862b6d7959725..196e2f3438c5b0503e7e9015507d626f059c12e5 100644 (file)
--- 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++;

diff --git a/tools/perf/util/path.c b/tools/perf/util/path.c
index 00adf872bf00ba28c3b0b6f2ca6a6dd5fec3ffdb..9712466c51e2f30efbe622c275c02e3ed4cf2bf8 100644 (file)
--- a/tools/perf/util/path.c
+++ b/tools/perf/util/path.c
@@ -68,6 +68,16 @@ bool is_directory(const char *base_path, const struct dirent *dent)
        return S_ISDIR(st.st_mode);
 }
 
+bool is_directory_at(int dir_fd, const char *path)
+{
+       struct stat st;
+
+       if (fstatat(dir_fd, path, &st, /*flags=*/0))
+               return false;
+
+       return S_ISDIR(st.st_mode);
+}
+
 bool is_executable_file(const char *base_path, const struct dirent *dent)
 {
        char path[PATH_MAX];

diff --git a/tools/perf/util/path.h b/tools/perf/util/path.h
index d94902c222223423b7401da9f9df130f3aec3da2..fbafbe7015dd0b3fe473671cbe5f4a85ff6de26d 100644 (file)
--- a/tools/perf/util/path.h
+++ b/tools/perf/util/path.h
@@ -12,6 +12,7 @@ int path__join3(char *bf, size_t size, const char *path1, const char *path2, con
 
 bool is_regular_file(const char *file);
 bool is_directory(const char *base_path, const struct dirent *dent);
+bool is_directory_at(int dir_fd, const char *path);
 bool is_executable_file(const char *base_path, const struct dirent *dent);
 
 #endif /* _PERF_PATH_H */