Fix: nestable pthread cancelstate

[lttng-ust.git] / liblttng-ust-comm / lttng-ust-fd-tracker.c

diff --git a/liblttng-ust-comm/lttng-ust-fd-tracker.c b/liblttng-ust-comm/lttng-ust-fd-tracker.c
index 42c3984cc2d3a390f941005f82a0315aa329c208..9909c0606a45044ab33f37ed09603d87d60dcf3c 100644 (file)
--- a/liblttng-ust-comm/lttng-ust-fd-tracker.c
+++ b/liblttng-ust-comm/lttng-ust-fd-tracker.c
@@ -42,6 +42,7 @@
 #include <helper.h>
 #include <lttng/ust-error.h>
 #include <usterr-signal-safe.h>
+#include <lttng/ust-cancelstate.h>
 
 #include "../liblttng-ust/compat.h"
 
@@ -69,28 +70,14 @@
  */
 static pthread_mutex_t ust_safe_guard_fd_mutex = PTHREAD_MUTEX_INITIALIZER;
 
-/*
- * Cancel state when grabbing the ust_safe_guard_fd_mutex. Saved when
- * locking, restored on unlock. Protected by ust_safe_guard_fd_mutex.
- */
-static int ust_safe_guard_saved_cancelstate;
-
 /*
  * Track whether we are within lttng-ust or application, for close
- * system call override by LD_PRELOAD library. Threads registered
- * as being lttng-ust listener threads need to perform fd tracker
- * locking explicitly around their use of file descriptor manipulation
- * functions.
- */
-static DEFINE_URCU_TLS(int, thread_fd_tracking);
-
-/*
- * Track whether we are invoking close() from a signal handler nested on
- * an application thread.
+ * system call override by LD_PRELOAD library. This also tracks whether
+ * we are invoking close() from a signal handler nested on an
+ * application thread.
  */
 static DEFINE_URCU_TLS(int, ust_fd_mutex_nest);
 
-
 /* fd_set used to book keep fd being used by lttng-ust. */
 static fd_set *lttng_fd_set;
 static int lttng_ust_max_fd;
@@ -102,7 +89,6 @@ static int init_done;
  */
 void lttng_ust_fixup_fd_tracker_tls(void)
 {
-       asm volatile ("" : : "m" (URCU_TLS(thread_fd_tracking)));
        asm volatile ("" : : "m" (URCU_TLS(ust_fd_mutex_nest)));
 }
 
@@ -148,11 +134,10 @@ void lttng_ust_init_fd_tracker(void)
 void lttng_ust_lock_fd_tracker(void)
 {
        sigset_t sig_all_blocked, orig_mask;
-       int ret, oldstate;
+       int ret;
 
-       ret = pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, &oldstate);
-       if (ret) {
-               ERR("pthread_setcancelstate: %s", strerror(ret));
+       if (lttng_ust_cancelstate_disable_push()) {
+               ERR("lttng_ust_cancelstate_disable_push");
        }
        sigfillset(&sig_all_blocked);
        ret = pthread_sigmask(SIG_SETMASK, &sig_all_blocked, &orig_mask);
@@ -166,7 +151,6 @@ void lttng_ust_lock_fd_tracker(void)
                 */
                cmm_barrier();
                pthread_mutex_lock(&ust_safe_guard_fd_mutex);
-               ust_safe_guard_saved_cancelstate = oldstate;
        }
        ret = pthread_sigmask(SIG_SETMASK, &orig_mask, NULL);
        if (ret) {
@@ -177,8 +161,7 @@ void lttng_ust_lock_fd_tracker(void)
 void lttng_ust_unlock_fd_tracker(void)
 {
        sigset_t sig_all_blocked, orig_mask;
-       int ret, newstate, oldstate;
-       bool restore_cancel = false;
+       int ret;
 
        sigfillset(&sig_all_blocked);
        ret = pthread_sigmask(SIG_SETMASK, &sig_all_blocked, &orig_mask);
@@ -191,19 +174,14 @@ void lttng_ust_unlock_fd_tracker(void)
         */
        cmm_barrier();
        if (!--URCU_TLS(ust_fd_mutex_nest)) {
-               newstate = ust_safe_guard_saved_cancelstate;
-               restore_cancel = true;
                pthread_mutex_unlock(&ust_safe_guard_fd_mutex);
        }
        ret = pthread_sigmask(SIG_SETMASK, &orig_mask, NULL);
        if (ret) {
                ERR("pthread_sigmask: %s", strerror(ret));
        }
-       if (restore_cancel) {
-               ret = pthread_setcancelstate(newstate, &oldstate);
-               if (ret) {
-                       ERR("pthread_setcancelstate: %s", strerror(ret));
-               }
+       if (lttng_ust_cancelstate_disable_pop()) {
+               ERR("lttng_ust_cancelstate_disable_pop");
        }
 }
 
@@ -357,7 +335,7 @@ int lttng_ust_safe_close_fd(int fd, int (*close_cb)(int fd))
         * If called from lttng-ust, we directly call close without
         * validating whether the FD is part of the tracked set.
         */
-       if (URCU_TLS(thread_fd_tracking))
+       if (URCU_TLS(ust_fd_mutex_nest))
                return close_cb(fd);
 
        lttng_ust_lock_fd_tracker();
@@ -393,7 +371,7 @@ int lttng_ust_safe_fclose_stream(FILE *stream, int (*fclose_cb)(FILE *stream))
         * If called from lttng-ust, we directly call fclose without
         * validating whether the FD is part of the tracked set.
         */
-       if (URCU_TLS(thread_fd_tracking))
+       if (URCU_TLS(ust_fd_mutex_nest))
                return fclose_cb(stream);
 
        fd = fileno(stream);
@@ -456,7 +434,7 @@ int lttng_ust_safe_closefrom_fd(int lowfd, int (*close_cb)(int fd))
         * If called from lttng-ust, we directly call close without
         * validating whether the FD is part of the tracked set.
         */
-       if (URCU_TLS(thread_fd_tracking)) {
+       if (URCU_TLS(ust_fd_mutex_nest)) {
                for (i = lowfd; i < lttng_ust_max_fd; i++) {
                        if (close_cb(i) < 0) {
                                switch (errno) {
@@ -501,8 +479,3 @@ int lttng_ust_safe_closefrom_fd(int lowfd, int (*close_cb)(int fd))
 end:
        return ret;
 }
-
-void lttng_ust_fd_tracker_register_thread(void)
-{
-       URCU_TLS(thread_fd_tracking) = 1;
-}