X-Git-Url: http://git.liburcu.org/?a=blobdiff_plain;f=liblttng-ust%2Flttng-ust-comm.c;h=ef8b6fedcf7b045d197223fdcea1056a530d59a0;hb=f488575f3420027d33050e779e1e3916e3b91c8c;hp=86cce18d57fe658588db907ed8016f39e95f975f;hpb=efe0de097e8e1cd372a7eb926e0ec68b97e6ee50;p=lttng-ust.git

diff --git a/liblttng-ust/lttng-ust-comm.c b/liblttng-ust/lttng-ust-comm.c
index 86cce18d..ef8b6fed 100644
--- a/liblttng-ust/lttng-ust-comm.c
+++ b/liblttng-ust/lttng-ust-comm.c
@@ -41,11 +41,14 @@
 #include <lttng/ust-events.h>
 #include <lttng/ust-abi.h>
 #include <lttng/ust.h>
+#include <lttng/ust-error.h>
 #include <ust-comm.h>
 #include <usterr-signal-safe.h>
+#include <helper.h>
 #include "tracepoint-internal.h"
 #include "ltt-tracer-core.h"
 #include "compat.h"
+#include "../libringbuffer/tlsfixup.h"
 
 /*
  * Has lttng ust comm constructor been called ?
@@ -77,6 +80,12 @@ 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.
  */
@@ -129,6 +138,15 @@ extern void ltt_ring_buffer_client_overwrite_exit(void);
 extern void ltt_ring_buffer_client_discard_exit(void);
 extern void ltt_ring_buffer_metadata_client_exit(void);
 
+/*
+ * Force a read (imply TLS fixup for dlopen) of TLS variables.
+ */
+static
+void lttng_fixup_nest_count_tls(void)
+{
+	asm volatile ("" : : "m" (lttng_ust_nest_count));
+}
+
 static
 int setup_local_apps(void)
 {
@@ -140,14 +158,16 @@ int setup_local_apps(void)
 	 * Disallow per-user tracing for setuid binaries.
 	 */
 	if (uid != geteuid()) {
-		local_apps.allowed = 0;
+		assert(local_apps.allowed == 0);
 		return 0;
-	} else {
-		local_apps.allowed = 1;
 	}
 	home_dir = (const char *) getenv("HOME");
-	if (!home_dir)
+	if (!home_dir) {
+		WARN("HOME environment variable not set. Disabling LTTng-UST per-user tracing.");
+		assert(local_apps.allowed == 0);
 		return -ENOENT;
+	}
+	local_apps.allowed = 1;
 	snprintf(local_apps.sock_path, PATH_MAX,
 		 DEFAULT_HOME_APPS_UNIX_SOCK, home_dir);
 	snprintf(local_apps.wait_shm_path, PATH_MAX,
@@ -195,15 +215,15 @@ int send_reply(int sock, struct ustcomm_ust_reply *lur)
 	case sizeof(*lur):
 		DBG("message successfully sent");
 		return 0;
-	case -1:
-		if (errno == ECONNRESET) {
-			printf("remote end closed connection\n");
+	default:
+		if (len == -ECONNRESET) {
+			DBG("remote end closed connection");
 			return 0;
 		}
-		return -1;
-	default:
-		printf("incorrect message size: %zd\n", len);
-		return -1;
+		if (len < 0)
+			return len;
+		DBG("incorrect message size: %zd", len);
+		return -EINVAL;
 	}
 }
 
@@ -235,6 +255,7 @@ 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();
 
@@ -264,11 +285,79 @@ int handle_message(struct sock_info *sock_info,
 		else
 			ret = lttng_ust_objd_unref(lum->handle);
 		break;
+	case LTTNG_UST_FILTER:
+	{
+		/* Receive filter data */
+		struct lttng_ust_filter_bytecode_node *bytecode;
+
+		if (lum->u.filter.data_size > FILTER_BYTECODE_MAX_LEN) {
+			ERR("Filter data size is too large: %u bytes",
+				lum->u.filter.data_size);
+			ret = -EINVAL;
+			goto error;
+		}
+
+		if (lum->u.filter.reloc_offset > lum->u.filter.data_size) {
+			ERR("Filter reloc offset %u is not within data",
+				lum->u.filter.reloc_offset);
+			ret = -EINVAL;
+			goto error;
+		}
+
+		bytecode = zmalloc(sizeof(*bytecode) + lum->u.filter.data_size);
+		if (!bytecode) {
+			ret = -ENOMEM;
+			goto error;
+		}
+		len = ustcomm_recv_unix_sock(sock, bytecode->bc.data,
+				lum->u.filter.data_size);
+		switch (len) {
+		case 0:	/* orderly shutdown */
+			ret = 0;
+			free(bytecode);
+			goto error;
+		default:
+			if (len == lum->u.filter.data_size) {
+				DBG("filter 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;
+					free(bytecode);
+					goto error;
+				}
+				ret = len;
+				goto end;
+			} else {
+				DBG("incorrect filter data message size: %zd", len);
+				ret = -EINVAL;
+				free(bytecode);
+				goto end;
+			}
+		}
+		bytecode->bc.len = lum->u.filter.data_size;
+		bytecode->bc.reloc_offset = lum->u.filter.reloc_offset;
+		if (ops->cmd) {
+			ret = ops->cmd(lum->handle, lum->cmd,
+					(unsigned long) bytecode,
+					&args, sock_info);
+			if (ret) {
+				free(bytecode);
+			}
+			/* don't free bytecode if everything went fine. */
+		} else {
+			ret = -ENOSYS;
+			free(bytecode);
+		}
+		break;
+	}
 	default:
 		if (ops->cmd)
 			ret = ops->cmd(lum->handle, lum->cmd,
 					(unsigned long) &lum->u,
-					&args);
+					&args, sock_info);
 		else
 			ret = -ENOSYS;
 		break;
@@ -279,52 +368,89 @@ end:
 	lur.cmd = lum->cmd;
 	lur.ret_val = ret;
 	if (ret >= 0) {
-		lur.ret_code = USTCOMM_OK;
+		lur.ret_code = LTTNG_UST_OK;
 	} else {
-		//lur.ret_code = USTCOMM_SESSION_FAIL;
-		lur.ret_code = ret;
-	}
-	switch (lum->cmd) {
-	case LTTNG_UST_STREAM:
 		/*
-		 * Special-case reply to send stream info.
-		 * Use lum.u output.
+		 * Use -LTTNG_UST_ERR as wildcard for UST internal
+		 * error that are not caused by the transport, except if
+		 * we already have a more precise error message to
+		 * report.
 		 */
-		lur.u.stream.memory_map_size = *args.stream.memory_map_size;
-		shm_fd = *args.stream.shm_fd;
-		wait_fd = *args.stream.wait_fd;
-		break;
-	case LTTNG_UST_METADATA:
-	case LTTNG_UST_CHANNEL:
-		lur.u.channel.memory_map_size = *args.channel.memory_map_size;
-		shm_fd = *args.channel.shm_fd;
-		wait_fd = *args.channel.wait_fd;
-		break;
-	case LTTNG_UST_TRACER_VERSION:
-		lur.u.version = lum->u.version;
-		break;
-	case LTTNG_UST_TRACEPOINT_LIST_GET:
-		memcpy(&lur.u.tracepoint, &lum->u.tracepoint, sizeof(lur.u.tracepoint));
-		break;
+		if (ret > -LTTNG_UST_ERR) {
+			/* Translate code to UST error. */
+			switch (ret) {
+			case -EEXIST:
+				lur.ret_code = -LTTNG_UST_ERR_EXIST;
+				break;
+			case -EINVAL:
+				lur.ret_code = -LTTNG_UST_ERR_INVAL;
+				break;
+			case -ENOENT:
+				lur.ret_code = -LTTNG_UST_ERR_NOENT;
+				break;
+			case -EPERM:
+				lur.ret_code = -LTTNG_UST_ERR_PERM;
+				break;
+			case -ENOSYS:
+				lur.ret_code = -LTTNG_UST_ERR_NOSYS;
+				break;
+			default:
+				lur.ret_code = -LTTNG_UST_ERR;
+				break;
+			}
+		} else {
+			lur.ret_code = ret;
+		}
+	}
+	if (ret >= 0) {
+		switch (lum->cmd) {
+		case LTTNG_UST_STREAM:
+			/*
+			 * Special-case reply to send stream info.
+			 * Use lum.u output.
+			 */
+			lur.u.stream.memory_map_size = *args.stream.memory_map_size;
+			shm_fd = *args.stream.shm_fd;
+			wait_fd = *args.stream.wait_fd;
+			break;
+		case LTTNG_UST_METADATA:
+		case LTTNG_UST_CHANNEL:
+			lur.u.channel.memory_map_size = *args.channel.memory_map_size;
+			shm_fd = *args.channel.shm_fd;
+			wait_fd = *args.channel.wait_fd;
+			break;
+		case LTTNG_UST_TRACER_VERSION:
+			lur.u.version = lum->u.version;
+			break;
+		case LTTNG_UST_TRACEPOINT_LIST_GET:
+			memcpy(&lur.u.tracepoint, &lum->u.tracepoint, sizeof(lur.u.tracepoint));
+			break;
+		}
 	}
 	ret = send_reply(sock, &lur);
 	if (ret < 0) {
-		perror("error sending reply");
+		DBG("error sending reply");
 		goto error;
 	}
 
 	if ((lum->cmd == LTTNG_UST_STREAM
 	     || lum->cmd == LTTNG_UST_CHANNEL
 	     || lum->cmd == LTTNG_UST_METADATA)
-			&& lur.ret_code == USTCOMM_OK) {
+			&& lur.ret_code == LTTNG_UST_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;
+			ERR("send shm_fd");
+			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));
@@ -332,6 +458,30 @@ 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 == LTTNG_UST_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 < 0) {
+				ret = len;
+				goto error;
+			}
+			if (len != sizeof(args.field_list.entry)) {
+				ret = -EINVAL;
+				goto error;
+			}
+		}
 	}
 	/*
 	 * We still have the memory map reference, and the fds have been
@@ -339,7 +489,7 @@ end:
 	 * that we keep the write side of the wait_fd open, but close
 	 * the read side.
 	 */
-	if (lur.ret_code == USTCOMM_OK) {
+	if (lur.ret_code == LTTNG_UST_OK) {
 		switch (lum->cmd) {
 		case LTTNG_UST_STREAM:
 			if (shm_fd >= 0) {
@@ -388,7 +538,7 @@ 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");
 		}
@@ -451,7 +601,9 @@ 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;
 
@@ -500,9 +652,9 @@ int get_wait_shm(struct sock_info *sock_info, size_t mmap_size)
 			ret = ftruncate(wait_shm_fd, mmap_size);
 			if (ret) {
 				PERROR("ftruncate");
-				exit(EXIT_FAILURE);
+				_exit(EXIT_FAILURE);
 			}
-			exit(EXIT_SUCCESS);
+			_exit(EXIT_SUCCESS);
 		}
 		/*
 		 * For local shm, we need to have rw access to accept
@@ -514,13 +666,13 @@ int get_wait_shm(struct sock_info *sock_info, size_t mmap_size)
 		 */
 		if (!sock_info->global && errno != EACCES) {
 			ERR("Error opening shm %s", sock_info->wait_shm_path);
-			exit(EXIT_FAILURE);
+			_exit(EXIT_FAILURE);
 		}
 		/*
 		 * The shm exists, but we cannot open it RW. Report
 		 * success.
 		 */
-		exit(EXIT_SUCCESS);
+		_exit(EXIT_SUCCESS);
 	} else {
 		return -1;
 	}
@@ -634,7 +786,7 @@ error:
  * This thread does not allocate any resource, except within
  * handle_message, within mutex protection. This mutex protects against
  * fork and exit.
- * The other moment it allocates resources is at socket connexion, which
+ * The other moment it allocates resources is at socket connection, which
  * is also protected by the mutex.
  */
 static
@@ -668,7 +820,7 @@ 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);
 		}
@@ -694,7 +846,8 @@ restart:
 
 	/*
 	 * Create only one root handle per listener thread for the whole
-	 * process lifetime.
+	 * process lifetime, so we ensure we get ID which is statically
+	 * assigned to the root handle.
 	 */
 	if (sock_info->root_handle == -1) {
 		ret = lttng_abi_create_root_handle();
@@ -728,7 +881,7 @@ restart:
 		len = ustcomm_recv_unix_sock(sock, &lum, sizeof(lum));
 		switch (len) {
 		case 0:	/* orderly shutdown */
-			DBG("%s ltt-sessiond has performed an orderly shutdown\n", sock_info->name);
+			DBG("%s ltt-sessiond has performed an orderly shutdown", sock_info->name);
 			ust_lock();
 			/*
 			 * Either sessiond has shutdown or refused us by closing the socket.
@@ -745,26 +898,31 @@ restart:
 			ust_unlock();
 			goto end;
 		case sizeof(lum):
-			DBG("message received\n");
+			DBG("message received");
 			ret = handle_message(sock_info, sock, &lum);
-			if (ret < 0) {
+			if (ret) {
 				ERR("Error handling message for %s socket", sock_info->name);
 			}
 			continue;
-		case -1:
-			DBG("Receive failed from lttng-sessiond with errno %d", errno);
-			if (errno == ECONNRESET) {
-				ERR("%s remote end closed connection\n", sock_info->name);
+		default:
+			if (len < 0) {
+				DBG("Receive failed from lttng-sessiond with errno %d", (int) -len);
+			} else {
+				DBG("incorrect message size (%s socket): %zd", sock_info->name, len);
+			}
+			if (len == -ECONNRESET) {
+				DBG("%s remote end closed connection", sock_info->name);
 				goto end;
 			}
 			goto end;
-		default:
-			ERR("incorrect message size (%s socket): %zd\n", sock_info->name, len);
-			continue;
 		}
 
 	}
 end:
+	ust_lock();
+	/* Cleanup socket handles before trying to reconnect */
+	lttng_ust_objd_table_owner_cleanup(sock_info);
+	ust_unlock();
 	goto restart;	/* try to reconnect */
 quit:
 	return NULL;
@@ -814,17 +972,28 @@ int get_timeout(struct timespec *constructor_timeout)
  * sessiond monitoring thread: monitor presence of global and per-user
  * sessiond by polling the application common named pipe.
  */
-/* TODO */
-
 void __attribute__((constructor)) lttng_ust_init(void)
 {
 	struct timespec constructor_timeout;
+	sigset_t sig_all_blocked, orig_parent_mask;
+	pthread_attr_t thread_attr;
 	int timeout_mode;
 	int ret;
 
 	if (uatomic_xchg(&initialized, 1) == 1)
 		return;
 
+	/*
+	 * Fixup interdependency between TLS fixup mutex (which happens
+	 * to be the dynamic linker mutex) and ust_lock, taken within
+	 * the ust lock.
+	 */
+	lttng_fixup_event_tls();
+	lttng_fixup_ringbuffer_tls();
+	lttng_fixup_vtid_tls();
+	lttng_fixup_nest_count_tls();
+	lttng_fixup_procname_tls();
+
 	/*
 	 * We want precise control over the order in which we construct
 	 * our sub-libraries vs starting to receive commands from
@@ -844,17 +1013,53 @@ void __attribute__((constructor)) lttng_ust_init(void)
 
 	ret = setup_local_apps();
 	if (ret) {
-		ERR("Error setting up to local apps");
+		DBG("local apps setup returned %d", ret);
+	}
+
+	/* 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(&local_apps.ust_listener, NULL,
-			ust_listener_thread, &local_apps);
 
+	ret = pthread_attr_init(&thread_attr);
+	if (ret) {
+		ERR("pthread_attr_init: %s", strerror(ret));
+	}
+	ret = pthread_attr_setdetachstate(&thread_attr, PTHREAD_CREATE_DETACHED);
+	if (ret) {
+		ERR("pthread_attr_setdetachstate: %s", strerror(ret));
+	}
+
+	ret = pthread_create(&global_apps.ust_listener, &thread_attr,
+			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, &thread_attr,
+				ust_listener_thread, &local_apps);
+		if (ret) {
+			ERR("pthread_create local: %s", strerror(ret));
+		}
 	} else {
 		handle_register_done(&local_apps);
 	}
+	ret = pthread_attr_destroy(&thread_attr);
+	if (ret) {
+		ERR("pthread_attr_destroy: %s", strerror(ret));
+	}
+
+	/* 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 */
@@ -929,12 +1134,14 @@ 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));
 		}
 	}
 	/*
@@ -966,6 +1173,8 @@ 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);
@@ -991,6 +1200,8 @@ 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 */
@@ -1008,6 +1219,8 @@ 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();