X-Git-Url: http://git.lttng.org/?a=blobdiff_plain;f=liblttng-ust%2Flttng-ust-comm.c;h=7a9097014d26e4d483f4d4a9f7d98cbd581807d9;hb=e8508a495280a1396a0319a157409a7ea61ffc5a;hp=2f2c783b189966d19181ae98bec17a020152c002;hpb=d51652f7ee9f3214b62c17441913168115ab4c9e;p=lttng-ust.git diff --git a/liblttng-ust/lttng-ust-comm.c b/liblttng-ust/lttng-ust-comm.c index 2f2c783b..7a909701 100644 --- a/liblttng-ust/lttng-ust-comm.c +++ b/liblttng-ust/lttng-ust-comm.c @@ -78,6 +78,12 @@ static sem_t constructor_wait; */ static int sem_count = { 2 }; +/* + * Counting nesting within lttng-ust. Used to ensure that calling fork() + * from liblttng-ust does not execute the pre/post fork handlers. + */ +static int __thread lttng_ust_nest_count; + /* * Info about socket and associated listener thread. */ @@ -236,6 +242,7 @@ int handle_message(struct sock_info *sock_info, struct ustcomm_ust_reply lur; int shm_fd, wait_fd; union ust_args args; + ssize_t len; ust_lock(); @@ -320,14 +327,20 @@ end: || lum->cmd == LTTNG_UST_CHANNEL || lum->cmd == LTTNG_UST_METADATA) && lur.ret_code == USTCOMM_OK) { + int sendret = 0; + /* we also need to send the file descriptors. */ ret = ustcomm_send_fds_unix_sock(sock, &shm_fd, &shm_fd, 1, sizeof(int)); if (ret < 0) { perror("send shm_fd"); - goto error; + sendret = ret; } + /* + * The sessiond expects 2 file descriptors, even upon + * error. + */ ret = ustcomm_send_fds_unix_sock(sock, &wait_fd, &wait_fd, 1, sizeof(int)); @@ -335,6 +348,26 @@ end: perror("send wait_fd"); goto error; } + if (sendret) { + ret = sendret; + goto error; + } + } + /* + * LTTNG_UST_TRACEPOINT_FIELD_LIST_GET needs to send the field + * after the reply. + */ + if (lur.ret_code == USTCOMM_OK) { + switch (lum->cmd) { + case LTTNG_UST_TRACEPOINT_FIELD_LIST_GET: + len = ustcomm_send_unix_sock(sock, + &args.field_list.entry, + sizeof(args.field_list.entry)); + if (len != sizeof(args.field_list.entry)) { + ret = -1; + goto error; + } + } } /* * We still have the memory map reference, and the fds have been @@ -391,7 +424,7 @@ void cleanup_sock_info(struct sock_info *sock_info, int exiting) int ret; if (sock_info->socket != -1) { - ret = close(sock_info->socket); + ret = ustcomm_close_unix_sock(sock_info->socket); if (ret) { ERR("Error closing apps socket"); } @@ -454,7 +487,9 @@ int get_wait_shm(struct sock_info *sock_info, size_t mmap_size) * If the open failed because the file did not exist, try * creating it ourself. */ + lttng_ust_nest_count++; pid = fork(); + lttng_ust_nest_count--; if (pid > 0) { int status; @@ -671,7 +706,7 @@ restart: } if (sock_info->socket != -1) { - ret = close(sock_info->socket); + ret = ustcomm_close_unix_sock(sock_info->socket); if (ret) { ERR("Error closing %s apps socket", sock_info->name); } @@ -822,6 +857,7 @@ int get_timeout(struct timespec *constructor_timeout) void __attribute__((constructor)) lttng_ust_init(void) { struct timespec constructor_timeout; + sigset_t sig_all_blocked, orig_parent_mask; int timeout_mode; int ret; @@ -835,6 +871,7 @@ void __attribute__((constructor)) lttng_ust_init(void) */ lttng_fixup_event_tls(); lttng_fixup_ringbuffer_tls(); + lttng_fixup_vtid_tls(); /* * We want precise control over the order in which we construct @@ -857,16 +894,39 @@ void __attribute__((constructor)) lttng_ust_init(void) if (ret) { ERR("Error setting up to local apps"); } - ret = pthread_create(&local_apps.ust_listener, NULL, - ust_listener_thread, &local_apps); + /* A new thread created by pthread_create inherits the signal mask + * from the parent. To avoid any signal being received by the + * listener thread, we block all signals temporarily in the parent, + * while we create the listener thread. + */ + sigfillset(&sig_all_blocked); + ret = pthread_sigmask(SIG_SETMASK, &sig_all_blocked, &orig_parent_mask); + if (ret) { + ERR("pthread_sigmask: %s", strerror(ret)); + } + + ret = pthread_create(&global_apps.ust_listener, NULL, + ust_listener_thread, &global_apps); + if (ret) { + ERR("pthread_create global: %s", strerror(ret)); + } if (local_apps.allowed) { - ret = pthread_create(&global_apps.ust_listener, NULL, - ust_listener_thread, &global_apps); + ret = pthread_create(&local_apps.ust_listener, NULL, + ust_listener_thread, &local_apps); + if (ret) { + ERR("pthread_create local: %s", strerror(ret)); + } } else { handle_register_done(&local_apps); } + /* Restore original signal mask in parent */ + ret = pthread_sigmask(SIG_SETMASK, &orig_parent_mask, NULL); + if (ret) { + ERR("pthread_sigmask: %s", strerror(ret)); + } + switch (timeout_mode) { case 1: /* timeout wait */ do { @@ -940,12 +1000,14 @@ void __attribute__((destructor)) lttng_ust_exit(void) /* cancel threads */ ret = pthread_cancel(global_apps.ust_listener); if (ret) { - ERR("Error cancelling global ust listener thread"); + ERR("Error cancelling global ust listener thread: %s", + strerror(ret)); } if (local_apps.allowed) { ret = pthread_cancel(local_apps.ust_listener); if (ret) { - ERR("Error cancelling local ust listener thread"); + ERR("Error cancelling local ust listener thread: %s", + strerror(ret)); } } /* @@ -977,6 +1039,8 @@ void ust_before_fork(sigset_t *save_sigset) sigset_t all_sigs; int ret; + if (lttng_ust_nest_count) + return; /* Disable signals */ sigfillset(&all_sigs); ret = sigprocmask(SIG_BLOCK, &all_sigs, save_sigset); @@ -1002,6 +1066,8 @@ static void ust_after_fork_common(sigset_t *restore_sigset) void ust_after_fork_parent(sigset_t *restore_sigset) { + if (lttng_ust_nest_count) + return; DBG("process %d", getpid()); rcu_bp_after_fork_parent(); /* Release mutexes and reenable signals */ @@ -1019,6 +1085,8 @@ void ust_after_fork_parent(sigset_t *restore_sigset) */ void ust_after_fork_child(sigset_t *restore_sigset) { + if (lttng_ust_nest_count) + return; DBG("process %d", getpid()); /* Release urcu mutexes */ rcu_bp_after_fork_child();