Fix: nestable pthread cancelstate

[lttng-ust.git] / src / lib / lttng-ust-common / fd-tracker.c

diff --git a/src/lib/lttng-ust-common/fd-tracker.c b/src/lib/lttng-ust-common/fd-tracker.c
index 026a9327f297ac016ca009763716eb308e752e37..8638ea021d5eada2d857b247d94aa2e44dbfb256 100644 (file)
--- a/src/lib/lttng-ust-common/fd-tracker.c
+++ b/src/lib/lttng-ust-common/fd-tracker.c
@@ -28,8 +28,11 @@
 #include "common/ust-fd.h"
 #include "common/macros.h"
 #include <lttng/ust-error.h>
+#include <lttng/ust-cancelstate.h>
 #include "common/logging.h"
 
+#include "lib/lttng-ust-common/fd-tracker.h"
+
 /* Operations on the fd set. */
 #define IS_FD_VALID(fd)                        ((fd) >= 0 && (fd) < lttng_ust_max_fd)
 #define GET_FD_SET_FOR_FD(fd, fd_sets) (&((fd_sets)[(fd) / FD_SETSIZE]))
@@ -46,7 +49,7 @@
 
 /*
  * Protect the lttng_fd_set. Nests within the ust_lock, and therefore
- * within the libc dl lock. Therefore, we need to fixup the TLS before
+ * within the libc dl lock. Therefore, we need to allocate the TLS before
  * nesting into this lock.
  *
  * The ust_safe_guard_fd_mutex nests within the ust_mutex. This mutex
@@ -54,12 +57,6 @@
  */
 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. This also tracks whether
@@ -75,9 +72,9 @@ static int num_fd_sets;
 static int init_done;
 
 /*
- * Force a read (imply TLS fixup for dlopen) of TLS variables.
+ * Force a read (imply TLS allocation for dlopen) of TLS variables.
  */
-void lttng_ust_fixup_fd_tracker_tls(void)
+void lttng_ust_fd_tracker_alloc_tls(void)
 {
        asm volatile ("" : : "m" (URCU_TLS(ust_fd_mutex_nest)));
 }
@@ -87,7 +84,7 @@ void lttng_ust_fixup_fd_tracker_tls(void)
  * process. This will be called during the constructor execution
  * and will also be called in the child after fork via lttng_ust_init.
  */
-void lttng_ust_init_fd_tracker(void)
+void lttng_ust_fd_tracker_init(void)
 {
        struct rlimit rlim;
        int i;
@@ -124,11 +121,10 @@ 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);
@@ -142,7 +138,6 @@ 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) {
@@ -153,8 +148,7 @@ 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);
@@ -167,19 +161,14 @@ 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");
        }
 }
 
@@ -269,7 +258,7 @@ int lttng_ust_add_fd_to_tracker(int fd)
         * Ensure the tracker is initialized when called from
         * constructors.
         */
-       lttng_ust_init_fd_tracker();
+       lttng_ust_fd_tracker_init();
        assert(URCU_TLS(ust_fd_mutex_nest));
 
        if (IS_FD_STD(fd)) {
@@ -282,7 +271,7 @@ int lttng_ust_add_fd_to_tracker(int fd)
 
        /* Trying to add an fd which we can not accommodate. */
        assert(IS_FD_VALID(fd));
-       /* Setting an fd thats already set. */
+       /* Setting an fd that's already set. */
        assert(!IS_FD_SET(fd, lttng_fd_set));
 
        ADD_FD_TO_SET(fd, lttng_fd_set);
@@ -301,7 +290,7 @@ void lttng_ust_delete_fd_from_tracker(int fd)
         * Ensure the tracker is initialized when called from
         * constructors.
         */
-       lttng_ust_init_fd_tracker();
+       lttng_ust_fd_tracker_init();
 
        assert(URCU_TLS(ust_fd_mutex_nest));
        /* Not a valid fd. */
@@ -321,13 +310,13 @@ int lttng_ust_safe_close_fd(int fd, int (*close_cb)(int fd))
 {
        int ret = 0;
 
-       lttng_ust_fixup_fd_tracker_tls();
+       lttng_ust_fd_tracker_alloc_tls();
 
        /*
         * Ensure the tracker is initialized when called from
         * constructors.
         */
-       lttng_ust_init_fd_tracker();
+       lttng_ust_fd_tracker_init();
 
        /*
         * If called from lttng-ust, we directly call close without
@@ -357,13 +346,13 @@ int lttng_ust_safe_fclose_stream(FILE *stream, int (*fclose_cb)(FILE *stream))
 {
        int ret = 0, fd;
 
-       lttng_ust_fixup_fd_tracker_tls();
+       lttng_ust_fd_tracker_alloc_tls();
 
        /*
         * Ensure the tracker is initialized when called from
         * constructors.
         */
-       lttng_ust_init_fd_tracker();
+       lttng_ust_fd_tracker_init();
 
        /*
         * If called from lttng-ust, we directly call fclose without
@@ -412,13 +401,13 @@ int lttng_ust_safe_closefrom_fd(int lowfd, int (*close_cb)(int fd))
 {
        int ret = 0, close_success = 0, i;
 
-       lttng_ust_fixup_fd_tracker_tls();
+       lttng_ust_fd_tracker_alloc_tls();
 
        /*
         * Ensure the tracker is initialized when called from
         * constructors.
         */
-       lttng_ust_init_fd_tracker();
+       lttng_ust_fd_tracker_init();
 
        if (lowfd < 0) {
                /*