perf tools: Use readdir() instead of deprecated readdir_r()

The readdir() function is thread safe as long as just one thread uses a
DIR, which is the case when parsing tracepoint event definitions, 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-wddn49r6bz6wq4ee3dxbl7lo@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

1 files changed, 30 insertions, 30 deletions

diff --git a/tools/perf/util/parse-events.c b/tools/perf/util/parse-events.c
index 4c19d5e79d8c..bcbc983d4b12 100644
--- a/tools/perf/util/parse-events.c
+++ b/tools/perf/util/parse-events.c
@@ -138,11 +138,11 @@ struct event_symbol event_symbols_sw[PERF_COUNT_SW_MAX] = {
 #define PERF_EVENT_TYPE(config)         __PERF_EVENT_FIELD(config, TYPE)
 #define PERF_EVENT_ID(config)           __PERF_EVENT_FIELD(config, EVENT)
 
-#define for_each_subsystem(sys_dir, sys_dirent, sys_next)              \
-        while (!readdir_r(sys_dir, &sys_dirent, &sys_next) && sys_next)        \
-        if (sys_dirent.d_type == DT_DIR &&                                     \
-           (strcmp(sys_dirent.d_name, ".")) &&                                 \
-           (strcmp(sys_dirent.d_name, "..")))
+#define for_each_subsystem(sys_dir, sys_dirent)                 \
+        while ((sys_dirent = readdir(sys_dir)) != NULL)         \
+                if (sys_dirent->d_type == DT_DIR &&             \
+                    (strcmp(sys_dirent->d_name, ".")) &&        \
+                    (strcmp(sys_dirent->d_name, "..")))
 
 static int tp_event_has_id(struct dirent *sys_dir, struct dirent *evt_dir)
 {
@@ -159,12 +159,12 @@ static int tp_event_has_id(struct dirent *sys_dir, struct dirent *evt_dir)
         return 0;
 }
 
-#define for_each_event(sys_dirent, evt_dir, evt_dirent, evt_next)              \
-        while (!readdir_r(evt_dir, &evt_dirent, &evt_next) && evt_next)        \
-        if (evt_dirent.d_type == DT_DIR &&                                     \
-           (strcmp(evt_dirent.d_name, ".")) &&                                 \
-           (strcmp(evt_dirent.d_name, "..")) &&                                \
-           (!tp_event_has_id(&sys_dirent, &evt_dirent)))
+#define for_each_event(sys_dirent, evt_dir, evt_dirent)         \
+        while ((evt_dirent = readdir(evt_dir)) != NULL)         \
+                if (evt_dirent->d_type == DT_DIR &&             \
+                    (strcmp(evt_dirent->d_name, ".")) &&        \
+                    (strcmp(evt_dirent->d_name, "..")) &&       \
+                    (!tp_event_has_id(sys_dirent, evt_dirent)))
 
 #define MAX_EVENT_LENGTH 512
 
@@ -173,7 +173,7 @@ struct tracepoint_path *tracepoint_id_to_path(u64 config)
 {
         struct tracepoint_path *path = NULL;
         DIR *sys_dir, *evt_dir;
-        struct dirent *sys_next, *evt_next, sys_dirent, evt_dirent;
+        struct dirent *sys_dirent, *evt_dirent;
         char id_buf[24];
         int fd;
         u64 id;
@@ -184,18 +184,18 @@ struct tracepoint_path *tracepoint_id_to_path(u64 config)
         if (!sys_dir)
                 return NULL;
 
-        for_each_subsystem(sys_dir, sys_dirent, sys_next) {
+        for_each_subsystem(sys_dir, sys_dirent) {
 
                 snprintf(dir_path, MAXPATHLEN, "%s/%s", tracing_events_path,
-                         sys_dirent.d_name);
+                         sys_dirent->d_name);
                 evt_dir = opendir(dir_path);
                 if (!evt_dir)
                         continue;
 
-                for_each_event(sys_dirent, evt_dir, evt_dirent, evt_next) {
+                for_each_event(sys_dirent, evt_dir, evt_dirent) {
 
                         snprintf(evt_path, MAXPATHLEN, "%s/%s/id", dir_path,
-                                 evt_dirent.d_name);
+                                 evt_dirent->d_name);
                         fd = open(evt_path, O_RDONLY);
                         if (fd < 0)
                                 continue;
@@ -220,9 +220,9 @@ struct tracepoint_path *tracepoint_id_to_path(u64 config)
                                         free(path);
                                         return NULL;
                                 }
-                                strncpy(path->system, sys_dirent.d_name,
+                                strncpy(path->system, sys_dirent->d_name,
                                         MAX_EVENT_LENGTH);
-                                strncpy(path->name, evt_dirent.d_name,
+                                strncpy(path->name, evt_dirent->d_name,
                                         MAX_EVENT_LENGTH);
                                 return path;
                         }
@@ -1812,7 +1812,7 @@ void print_tracepoint_events(const char *subsys_glob, const char *event_glob,
                              bool name_only)
 {
         DIR *sys_dir, *evt_dir;
-        struct dirent *sys_next, *evt_next, sys_dirent, evt_dirent;
+        struct dirent *sys_dirent, *evt_dirent;
         char evt_path[MAXPATHLEN];
         char dir_path[MAXPATHLEN];
         char **evt_list = NULL;
@@ -1830,20 +1830,20 @@ restart:
                         goto out_close_sys_dir;
         }
 
-        for_each_subsystem(sys_dir, sys_dirent, sys_next) {
+        for_each_subsystem(sys_dir, sys_dirent) {
                 if (subsys_glob != NULL &&
-                    !strglobmatch(sys_dirent.d_name, subsys_glob))
+                    !strglobmatch(sys_dirent->d_name, subsys_glob))
                         continue;
 
                 snprintf(dir_path, MAXPATHLEN, "%s/%s", tracing_events_path,
-                         sys_dirent.d_name);
+                         sys_dirent->d_name);
                 evt_dir = opendir(dir_path);
                 if (!evt_dir)
                         continue;
 
-                for_each_event(sys_dirent, evt_dir, evt_dirent, evt_next) {
+                for_each_event(sys_dirent, evt_dir, evt_dirent) {
                         if (event_glob != NULL &&
-                            !strglobmatch(evt_dirent.d_name, event_glob))
+                            !strglobmatch(evt_dirent->d_name, event_glob))
                                 continue;
 
                         if (!evt_num_known) {
@@ -1852,7 +1852,7 @@ restart:
                         }
 
                         snprintf(evt_path, MAXPATHLEN, "%s:%s",
-                                 sys_dirent.d_name, evt_dirent.d_name);
+                                 sys_dirent->d_name, evt_dirent->d_name);
 
                         evt_list[evt_i] = strdup(evt_path);
                         if (evt_list[evt_i] == NULL)
@@ -1905,7 +1905,7 @@ out_close_sys_dir:
 int is_valid_tracepoint(const char *event_string)
 {
         DIR *sys_dir, *evt_dir;
-        struct dirent *sys_next, *evt_next, sys_dirent, evt_dirent;
+        struct dirent *sys_dirent, *evt_dirent;
         char evt_path[MAXPATHLEN];
         char dir_path[MAXPATHLEN];
 
@@ -1913,17 +1913,17 @@ int is_valid_tracepoint(const char *event_string)
         if (!sys_dir)
                 return 0;
 
-        for_each_subsystem(sys_dir, sys_dirent, sys_next) {
+        for_each_subsystem(sys_dir, sys_dirent) {
 
                 snprintf(dir_path, MAXPATHLEN, "%s/%s", tracing_events_path,
-                         sys_dirent.d_name);
+                         sys_dirent->d_name);
                 evt_dir = opendir(dir_path);
                 if (!evt_dir)
                         continue;
 
-                for_each_event(sys_dirent, evt_dir, evt_dirent, evt_next) {
+                for_each_event(sys_dirent, evt_dir, evt_dirent) {
                         snprintf(evt_path, MAXPATHLEN, "%s:%s",
-                                 sys_dirent.d_name, evt_dirent.d_name);
+                                 sys_dirent->d_name, evt_dirent->d_name);
                         if (!strcmp(evt_path, event_string)) {
                                 closedir(evt_dir);
                                 closedir(sys_dir);