Fix: UST comm protocol: event notifier command is too large

[deliverable/lttng-ust.git] / liblttng-ust / lttng-ust-comm.c

diff --git a/liblttng-ust/lttng-ust-comm.c b/liblttng-ust/lttng-ust-comm.c
index 4b13571df3b0a3edf46e90162545e91cf9080e04..59f14050f1b5dfdd4d53dc73d3730d9387a96142 100644 (file)
--- a/liblttng-ust/lttng-ust-comm.c
+++ b/liblttng-ust/lttng-ust-comm.c
@@ -39,8 +39,9 @@
 #include <signal.h>
 #include <limits.h>
 #include <urcu/uatomic.h>
-#include <urcu/futex.h>
+#include "futex.h"
 #include <urcu/compiler.h>
+#include <lttng/urcu/urcu-ust.h>
 
 #include <lttng/align.h>
 #include <lttng/ust-events.h>
@@ -434,8 +435,7 @@ void lttng_fixup_ust_mutex_nest_tls(void)
 static
 void lttng_fixup_urcu_bp_tls(void)
 {
-       rcu_read_lock();
-       rcu_read_unlock();
+       (void) lttng_ust_urcu_read_ongoing();
 }
 
 void lttng_ust_fixup_tls(void)
@@ -1216,6 +1216,48 @@ int handle_message(struct sock_info *sock_info,
                        ret = -ENOSYS;
                break;
        }
+       case LTTNG_UST_EVENT_NOTIFIER_CREATE:
+       {
+               /* Receive struct lttng_ust_event_notifier */
+               struct lttng_ust_event_notifier event_notifier;
+
+               if (sizeof(event_notifier) != lum->u.event_notifier.len) {
+                       DBG("incorrect event notifier data message size: %u", lum->u.event_notifier.len);
+                       ret = -EINVAL;
+                       goto error;
+               }
+               len = ustcomm_recv_unix_sock(sock, &event_notifier, sizeof(event_notifier));
+               switch (len) {
+               case 0: /* orderly shutdown */
+                       ret = 0;
+                       goto error;
+               default:
+                       if (len == sizeof(event_notifier)) {
+                               DBG("event notifier data received");
+                               break;
+                       } else if (len < 0) {
+                               DBG("Receive failed from lttng-sessiond with errno %d", (int) -len);
+                               if (len == -ECONNRESET) {
+                                       ERR("%s remote end closed connection", sock_info->name);
+                                       ret = len;
+                                       goto error;
+                               }
+                               ret = len;
+                               goto error;
+                       } else {
+                               DBG("incorrect event notifier data message size: %zd", len);
+                               ret = -EINVAL;
+                               goto error;
+                       }
+               }
+               if (ops->cmd)
+                       ret = ops->cmd(lum->handle, lum->cmd,
+                                       (unsigned long) &event_notifier,
+                                       &args, sock_info);
+               else
+                       ret = -ENOSYS;
+               break;
+       }
 
        default:
                if (ops->cmd)
@@ -1624,7 +1666,7 @@ void wait_for_sessiond(struct sock_info *sock_info)
        if (uatomic_read((int32_t *) sock_info->wait_shm_mmap))
                goto end_wait;
 
-       while (futex_async((int32_t *) sock_info->wait_shm_mmap,
+       while (lttng_ust_futex_async((int32_t *) sock_info->wait_shm_mmap,
                        FUTEX_WAIT, 0, NULL, NULL, 0)) {
                switch (errno) {
                case EWOULDBLOCK:
@@ -2315,7 +2357,9 @@ void ust_before_fork(sigset_t *save_sigset)
        pthread_mutex_lock(&ust_fork_mutex);
 
        ust_lock_nocheck();
-       urcu_bp_before_fork();
+       lttng_ust_urcu_before_fork();
+       if (lttng_ust_liburcu_bp_before_fork)
+               lttng_ust_liburcu_bp_before_fork();
        lttng_ust_lock_fd_tracker();
        lttng_perf_lock();
 }
@@ -2343,7 +2387,9 @@ void ust_after_fork_parent(sigset_t *restore_sigset)
        if (URCU_TLS(lttng_ust_nest_count))
                return;
        DBG("process %d", getpid());
-       urcu_bp_after_fork_parent();
+       lttng_ust_urcu_after_fork_parent();
+       if (lttng_ust_liburcu_bp_after_fork_parent)
+               lttng_ust_liburcu_bp_after_fork_parent();
        /* Release mutexes and reenable signals */
        ust_after_fork_common(restore_sigset);
 }
@@ -2369,7 +2415,9 @@ void ust_after_fork_child(sigset_t *restore_sigset)
        ust_context_vgids_reset();
        DBG("process %d", getpid());
        /* Release urcu mutexes */
-       urcu_bp_after_fork_child();
+       lttng_ust_urcu_after_fork_child();
+       if (lttng_ust_liburcu_bp_after_fork_child)
+               lttng_ust_liburcu_bp_after_fork_child();
        lttng_ust_cleanup(0);
        /* Release mutexes and reenable signals */
        ust_after_fork_common(restore_sigset);