[PATCH 3.16 354/366] perf script: Use readdir() instead of deprecated readdir_r()

Ben Hutchings
2018-11-11T20:31:07Z

From: Arnaldo Carvalho de Melo <acme@redhat.com>

commit a5e8e825bd1704c488bf6a46936aaf3b9f203d6a upstream.

The readdir() function is thread safe as long as just one thread uses a
DIR, which is the case in 'perf script', so, to avoid breaking the build
with glibc-2.23.90 (upcoming 2.24), use it instead of readdir_r().

See: http://man7.org/linux/man-pages/man3/readdir.3.html

"However, in modern implementations (including the glibc implementation),
concurrent calls to readdir() that specify different directory streams
are thread-safe. In cases where multiple threads must read from the
same directory stream, using readdir() with external synchronization is
still preferable to the use of the deprecated readdir_r(3) function."

Noticed while building on a Fedora Rawhide docker container.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-mt3xz7n2hl49ni2vx7kuq74g@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
---
tools/perf/builtin-script.c | 70 ++++++++++++++++++-------------------
1 file changed, 34 insertions(+), 36 deletions(-)

--- a/tools/perf/builtin-script.c
+++ b/tools/perf/builtin-script.c
@@ -1061,21 +1061,19 @@ static int is_directory(const char *base
return S_ISDIR(st.st_mode);
}

-#define for_each_lang(scripts_path, scripts_dir, lang_dirent, lang_next)\
- while (!readdir_r(scripts_dir, &lang_dirent, &lang_next) && \
- lang_next) \
- if ((lang_dirent.d_type == DT_DIR || \
- (lang_dirent.d_type == DT_UNKNOWN && \
- is_directory(scripts_path, &lang_dirent))) && \
- (strcmp(lang_dirent.d_name, ".")) && \
- (strcmp(lang_dirent.d_name, "..")))
-
-#define for_each_script(lang_path, lang_dir, script_dirent, script_next)\
- while (!readdir_r(lang_dir, &script_dirent, &script_next) && \
- script_next) \
- if (script_dirent.d_type != DT_DIR && \
- (script_dirent.d_type != DT_UNKNOWN || \
- !is_directory(lang_path, &script_dirent)))
+#define for_each_lang(scripts_path, scripts_dir, lang_dirent) \
+ while ((lang_dirent = readdir(scripts_dir)) != NULL) \
+ if ((lang_dirent->d_type == DT_DIR || \
+ (lang_dirent->d_type == DT_UNKNOWN && \
+ is_directory(scripts_path, lang_dirent))) && \
+ (strcmp(lang_dirent->d_name, ".")) && \
+ (strcmp(lang_dirent->d_name, "..")))
+
+#define for_each_script(lang_path, lang_dir, script_dirent) \
+ while ((script_dirent = readdir(lang_dir)) != NULL) \
+ if (script_dirent->d_type != DT_DIR && \
+ (script_dirent->d_type != DT_UNKNOWN || \
+ !is_directory(lang_path, script_dirent)))

#define RECORD_SUFFIX "-record"
@@ -1221,7 +1219,7 @@ static int list_available_scripts(const
const char *s __maybe_unused,
int unset __maybe_unused)
{
- struct dirent *script_next, *lang_next, script_dirent, lang_dirent;
+ struct dirent *script_dirent, *lang_dirent;
char scripts_path[MAXPATHLEN];
DIR *scripts_dir, *lang_dir;
char script_path[MAXPATHLEN];
@@ -1236,19 +1234,19 @@ static int list_available_scripts(const
if (!scripts_dir)
return -1;

- for_each_lang(scripts_path, scripts_dir, lang_dirent, lang_next) {
+ for_each_lang(scripts_path, scripts_dir, lang_dirent) {
snprintf(lang_path, MAXPATHLEN, "%s/%s/bin", scripts_path,
- lang_dirent.d_name);
+ lang_dirent->d_name);
lang_dir = opendir(lang_path);
if (!lang_dir)
continue;

- for_each_script(lang_path, lang_dir, script_dirent, script_next) {
- script_root = get_script_root(&script_dirent, REPORT_SUFFIX);
+ for_each_script(lang_path, lang_dir, script_dirent) {
+ script_root = get_script_root(script_dirent, REPORT_SUFFIX);
if (script_root) {
desc = script_desc__findnew(script_root);
snprintf(script_path, MAXPATHLEN, "%s/%s",
- lang_path, script_dirent.d_name);
+ lang_path, script_dirent->d_name);
read_script_info(desc, script_path);
free(script_root);
}
@@ -1336,7 +1334,7 @@ static int check_ev_match(char *dir_name
*/
int find_scripts(char **scripts_array, char **scripts_path_array)
{
- struct dirent *script_next, *lang_next, script_dirent, lang_dirent;
+ struct dirent *script_dirent, *lang_dirent;
char scripts_path[MAXPATHLEN], lang_path[MAXPATHLEN];
DIR *scripts_dir, *lang_dir;
struct perf_session *session;
@@ -1359,9 +1357,9 @@ int find_scripts(char **scripts_array, c
return -1;
}

- for_each_lang(scripts_path, scripts_dir, lang_dirent, lang_next) {
+ for_each_lang(scripts_path, scripts_dir, lang_dirent) {
snprintf(lang_path, MAXPATHLEN, "%s/%s", scripts_path,
- lang_dirent.d_name);
+ lang_dirent->d_name);
#ifdef NO_LIBPERL
if (strstr(lang_path, "perl"))
continue;
@@ -1375,16 +1373,16 @@ int find_scripts(char **scripts_array, c
if (!lang_dir)
continue;

- for_each_script(lang_path, lang_dir, script_dirent, script_next) {
+ for_each_script(lang_path, lang_dir, script_dirent) {
/* Skip those real time scripts: xxxtop.p[yl] */
- if (strstr(script_dirent.d_name, "top."))
+ if (strstr(script_dirent->d_name, "top."))
continue;
sprintf(scripts_path_array[i], "%s/%s", lang_path,
- script_dirent.d_name);
- temp = strchr(script_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);
+ (temp - script_dirent->d_name) + 1,
+ "%s", script_dirent->d_name);

if (check_ev_match(lang_path,
scripts_array[i], session))
@@ -1402,7 +1400,7 @@ int find_scripts(char **scripts_array, c

static char *get_script_path(const char *script_root, const char *suffix)
{
- struct dirent *script_next, *lang_next, script_dirent, lang_dirent;
+ struct dirent *script_dirent, *lang_dirent;
char scripts_path[MAXPATHLEN];
char script_path[MAXPATHLEN];
DIR *scripts_dir, *lang_dir;
@@ -1415,21 +1413,21 @@ static char *get_script_path(const char
if (!scripts_dir)
return NULL;

- for_each_lang(scripts_path, scripts_dir, lang_dirent, lang_next) {
+ for_each_lang(scripts_path, scripts_dir, lang_dirent) {
snprintf(lang_path, MAXPATHLEN, "%s/%s/bin", scripts_path,
- lang_dirent.d_name);
+ lang_dirent->d_name);
lang_dir = opendir(lang_path);
if (!lang_dir)
continue;

- for_each_script(lang_path, lang_dir, script_dirent, script_next) {
- __script_root = get_script_root(&script_dirent, suffix);
+ for_each_script(lang_path, lang_dir, script_dirent) {
+ __script_root = get_script_root(script_dirent, suffix);
if (__script_root && !strcmp(script_root, __script_root)) {
free(__script_root);
closedir(lang_dir);
closedir(scripts_dir);
snprintf(script_path, MAXPATHLEN, "%s/%s",
- lang_path, script_dirent.d_name);
+ lang_path, script_dirent->d_name);
return strdup(script_path);
}
free(__script_root);