X-Git-Url: https://git.lttng.org/?a=blobdiff_plain;f=src%2Flib%2Flttng-ust%2Flttng-ust-comm.c;h=2c902dc2737e922204628293e806306fa08e174a;hb=c117e9884c3acc65408d8f65b2cd86a8511df1cc;hp=219ef5d21ca64a21c08457c86f8b822d73efc540;hpb=247c2ecd8e17ab02996e45cfa1be254b04161210;p=lttng-ust.git

diff --git a/src/lib/lttng-ust/lttng-ust-comm.c b/src/lib/lttng-ust/lttng-ust-comm.c
index 219ef5d2..2c902dc2 100644
--- a/src/lib/lttng-ust/lttng-ust-comm.c
+++ b/src/lib/lttng-ust/lttng-ust-comm.c
@@ -25,7 +25,6 @@
 #include <signal.h>
 #include <limits.h>
 #include <urcu/uatomic.h>
-#include "futex.h"
 #include <urcu/compiler.h>
 #include <lttng/urcu/urcu-ust.h>
 
@@ -38,25 +37,26 @@
 #include <lttng/ust-libc-wrapper.h>
 #include <lttng/ust-thread.h>
 #include <lttng/ust-tracer.h>
+#include <lttng/ust-common.h>
 #include <urcu/tls-compat.h>
+#include "lib/lttng-ust/futex.h"
 #include "common/ustcomm.h"
 #include "common/ust-fd.h"
 #include "common/logging.h"
 #include "common/macros.h"
-#include "tracepoint-internal.h"
+#include "common/tracepoint.h"
 #include "lttng-tracer-core.h"
 #include "common/compat/pthread.h"
 #include "common/procname.h"
 #include "common/ringbuffer/rb-init.h"
 #include "lttng-ust-statedump.h"
-#include "clock.h"
-#include "lib/lttng-ust/getcpu.h"
-#include "getenv.h"
-#include "ust-events-internal.h"
+#include "common/clock.h"
+#include "common/getenv.h"
+#include "lib/lttng-ust/events.h"
 #include "context-internal.h"
 #include "common/align.h"
-#include "lttng-counter-client.h"
-#include "lttng-rb-clients.h"
+#include "common/counter-clients/clients.h"
+#include "common/ringbuffer-clients/clients.h"
 
 /*
  * Has lttng ust comm constructor been called ?
@@ -263,7 +263,7 @@ struct sock_info {
 };
 
 /* Socket from app (connect) to session daemon (listen) for communication */
-struct sock_info global_apps = {
+static struct sock_info global_apps = {
 	.name = "global",
 	.global = 1,
 
@@ -285,7 +285,7 @@ struct sock_info global_apps = {
 
 /* TODO: allow global_apps_sock_path override */
 
-struct sock_info local_apps = {
+static struct sock_info local_apps = {
 	.name = "local",
 	.global = 0,
 	.root_handle = -1,
@@ -356,24 +356,6 @@ static int got_timeout_env;
 
 static char *get_map_shm(struct sock_info *sock_info);
 
-ssize_t lttng_ust_read(int fd, void *buf, size_t len)
-{
-	ssize_t ret;
-	size_t copied = 0, to_copy = len;
-
-	do {
-		ret = read(fd, buf + copied, to_copy);
-		if (ret > 0) {
-			copied += ret;
-			to_copy -= ret;
-		}
-	} while ((ret > 0 && to_copy > 0)
-		|| (ret < 0 && errno == EINTR));
-	if (ret > 0) {
-		ret = copied;
-	}
-	return ret;
-}
 /*
  * Returns the HOME directory path. Caller MUST NOT free(3) the returned
  * pointer.
@@ -391,48 +373,48 @@ const char *get_lttng_home_dir(void)
 }
 
 /*
- * Force a read (imply TLS fixup for dlopen) of TLS variables.
+ * Force a read (imply TLS allocation for dlopen) of TLS variables.
  */
 static
-void lttng_fixup_nest_count_tls(void)
+void lttng_nest_count_alloc_tls(void)
 {
 	asm volatile ("" : : "m" (URCU_TLS(lttng_ust_nest_count)));
 }
 
 static
-void lttng_fixup_ust_mutex_nest_tls(void)
+void lttng_ust_mutex_nest_alloc_tls(void)
 {
 	asm volatile ("" : : "m" (URCU_TLS(ust_mutex_nest)));
 }
 
 /*
- * Fixup lttng-ust urcu TLS.
+ * Allocate lttng-ust urcu TLS.
  */
 static
-void lttng_fixup_lttng_ust_urcu_tls(void)
+void lttng_lttng_ust_urcu_alloc_tls(void)
 {
 	(void) lttng_ust_urcu_read_ongoing();
 }
 
-void lttng_ust_fixup_tls(void)
+void lttng_ust_alloc_tls(void)
 {
-	lttng_fixup_lttng_ust_urcu_tls();
-	lttng_fixup_ringbuffer_tls();
-	lttng_fixup_vtid_tls();
-	lttng_fixup_nest_count_tls();
-	lttng_fixup_procname_tls();
-	lttng_fixup_ust_mutex_nest_tls();
-	lttng_ust_fixup_perf_counter_tls();
-	lttng_ust_fixup_fd_tracker_tls();
-	lttng_fixup_cgroup_ns_tls();
-	lttng_fixup_ipc_ns_tls();
-	lttng_fixup_net_ns_tls();
-	lttng_fixup_time_ns_tls();
-	lttng_fixup_uts_ns_tls();
-	lttng_ust_fixup_ring_buffer_client_discard_tls();
-	lttng_ust_fixup_ring_buffer_client_discard_rt_tls();
-	lttng_ust_fixup_ring_buffer_client_overwrite_tls();
-	lttng_ust_fixup_ring_buffer_client_overwrite_rt_tls();
+	lttng_lttng_ust_urcu_alloc_tls();
+	lttng_ringbuffer_alloc_tls();
+	lttng_vtid_alloc_tls();
+	lttng_nest_count_alloc_tls();
+	lttng_procname_alloc_tls();
+	lttng_ust_mutex_nest_alloc_tls();
+	lttng_ust_perf_counter_alloc_tls();
+	lttng_ust_common_alloc_tls();
+	lttng_cgroup_ns_alloc_tls();
+	lttng_ipc_ns_alloc_tls();
+	lttng_net_ns_alloc_tls();
+	lttng_time_ns_alloc_tls();
+	lttng_uts_ns_alloc_tls();
+	lttng_ust_ring_buffer_client_discard_alloc_tls();
+	lttng_ust_ring_buffer_client_discard_rt_alloc_tls();
+	lttng_ust_ring_buffer_client_overwrite_alloc_tls();
+	lttng_ust_ring_buffer_client_overwrite_rt_alloc_tls();
 }
 
 /*
@@ -453,7 +435,7 @@ void lttng_ust_init_thread(void)
 	 * ensure those are initialized before a signal handler nesting over
 	 * this thread attempts to use them.
 	 */
-	lttng_ust_fixup_tls();
+	lttng_ust_alloc_tls();
 }
 
 int lttng_get_notify_socket(void *owner)
@@ -638,7 +620,8 @@ void get_allow_blocking(void)
 }
 
 static
-int register_to_sessiond(int socket, enum ustctl_socket_type type)
+int register_to_sessiond(int socket, enum lttng_ust_ctl_socket_type type,
+		const char *procname)
 {
 	return ustcomm_send_reg_msg(socket,
 		type,
@@ -647,7 +630,8 @@ int register_to_sessiond(int socket, enum ustctl_socket_type type)
 		lttng_ust_rb_alignof(uint16_t) * CHAR_BIT,
 		lttng_ust_rb_alignof(uint32_t) * CHAR_BIT,
 		lttng_ust_rb_alignof(uint64_t) * CHAR_BIT,
-		lttng_ust_rb_alignof(unsigned long) * CHAR_BIT);
+		lttng_ust_rb_alignof(unsigned long) * CHAR_BIT,
+		procname);
 }
 
 static
@@ -872,6 +856,49 @@ end:
 	return ret;
 }
 
+static
+void prepare_cmd_reply(struct ustcomm_ust_reply *lur, uint32_t handle, uint32_t cmd, int ret)
+{
+	lur->handle = handle;
+	lur->cmd = cmd;
+	lur->ret_val = ret;
+	if (ret >= 0) {
+		lur->ret_code = LTTNG_UST_OK;
+	} else {
+		/*
+		 * 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.
+		 */
+		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;
+		}
+	}
+}
+
 static
 int handle_message(struct sock_info *sock_info,
 		int sock, struct ustcomm_ust_msg *lum)
@@ -896,6 +923,52 @@ int handle_message(struct sock_info *sock_info,
 		goto error;
 	}
 
+	switch (lum->cmd) {
+	case LTTNG_UST_ABI_FILTER:
+	case LTTNG_UST_ABI_EXCLUSION:
+	case LTTNG_UST_ABI_CHANNEL:
+	case LTTNG_UST_ABI_STREAM:
+	case LTTNG_UST_ABI_CONTEXT:
+		/*
+		 * Those commands send additional payload after struct
+		 * ustcomm_ust_msg, which makes it pretty much impossible to
+		 * deal with "unknown command" errors without leaving the
+		 * communication pipe in a out-of-sync state. This is part of
+		 * the ABI between liblttng-ust-ctl and liblttng-ust, and
+		 * should be fixed on the next breaking
+		 * LTTNG_UST_ABI_MAJOR_VERSION protocol bump by indicating the
+		 * total command message length as part of a message header so
+		 * that the protocol can recover from invalid command errors.
+		 */
+		break;
+
+	case LTTNG_UST_ABI_CAPTURE:
+	case LTTNG_UST_ABI_COUNTER:
+	case LTTNG_UST_ABI_COUNTER_GLOBAL:
+	case LTTNG_UST_ABI_COUNTER_CPU:
+	case LTTNG_UST_ABI_EVENT_NOTIFIER_CREATE:
+	case LTTNG_UST_ABI_EVENT_NOTIFIER_GROUP_CREATE:
+		/*
+		 * Those commands expect a reply to the struct ustcomm_ust_msg
+		 * before sending additional payload.
+		 */
+		prepare_cmd_reply(&lur, lum->handle, lum->cmd, 0);
+
+		ret = send_reply(sock, &lur);
+		if (ret < 0) {
+			DBG("error sending reply");
+			goto error;
+		}
+		break;
+
+	default:
+		/*
+		 * Other commands either don't send additional payload, or are
+		 * unknown.
+		 */
+		break;
+	}
+
 	switch (lum->cmd) {
 	case LTTNG_UST_ABI_REGISTER_DONE:
 		if (lum->handle == LTTNG_UST_ABI_ROOT_HANDLE)
@@ -1313,44 +1386,8 @@ int handle_message(struct sock_info *sock_info,
 		break;
 	}
 
-	lur.handle = lum->handle;
-	lur.cmd = lum->cmd;
-	lur.ret_val = ret;
-	if (ret >= 0) {
-		lur.ret_code = LTTNG_UST_OK;
-	} else {
-		/*
-		 * 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.
-		 */
-		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;
-		}
-	}
+	prepare_cmd_reply(&lur, lum->handle, lum->cmd, ret);
+
 	if (ret >= 0) {
 		switch (lum->cmd) {
 		case LTTNG_UST_ABI_TRACER_VERSION:
@@ -1758,7 +1795,7 @@ void *ust_listener_thread(void *arg)
 	int sock, ret, prev_connect_failed = 0, has_waited = 0, fd;
 	long timeout;
 
-	lttng_ust_fixup_tls();
+	lttng_ust_alloc_tls();
 	/*
 	 * If available, add '-ust' to the end of this thread's
 	 * process name
@@ -1876,7 +1913,8 @@ restart:
 		sock_info->root_handle = ret;
 	}
 
-	ret = register_to_sessiond(sock_info->socket, USTCTL_SOCKET_CMD);
+	ret = register_to_sessiond(sock_info->socket, LTTNG_UST_CTL_SOCKET_CMD,
+		sock_info->procname);
 	if (ret < 0) {
 		ERR("Error registering to %s ust cmd socket",
 			sock_info->name);
@@ -1969,7 +2007,7 @@ restart:
 	}
 
 	ret = register_to_sessiond(sock_info->notify_socket,
-			USTCTL_SOCKET_NOTIFY);
+			LTTNG_UST_CTL_SOCKET_NOTIFY, sock_info->procname);
 	if (ret < 0) {
 		ERR("Error registering to %s ust notify socket",
 			sock_info->name);
@@ -2061,19 +2099,50 @@ quit:
  * Weak symbol to call when the ust malloc wrapper is not loaded.
  */
 __attribute__((weak))
-void lttng_ust_libc_wrapper_malloc_init(void)
+void lttng_ust_libc_wrapper_malloc_ctor(void)
 {
 }
 
+/*
+ * Use a symbol of the previous ABI to detect if liblttng-ust.so.0 is loaded in
+ * the current process.
+ */
+#define LTTNG_UST_SONAME_0_SYM	"ltt_probe_register"
+
+static
+void lttng_ust_check_soname_0(void)
+{
+	if (!dlsym(RTLD_DEFAULT, LTTNG_UST_SONAME_0_SYM))
+		return;
+
+	CRIT("Incompatible library ABIs detected within the same process. "
+		"The process is likely linked against different major soname of LTTng-UST which is unsupported. "
+		"The detection was triggered by lookup of ABI 0 symbol \"%s\" in the Global Symbol Table\n",
+		LTTNG_UST_SONAME_0_SYM);
+}
+
+/*
+ * Expose a canary symbol of the previous ABI to ensure we catch uses of a
+ * liblttng-ust.so.0 dlopen'd after .so.1 has been loaded. Use a different
+ * symbol than the detection code to ensure we don't detect ourself.
+ */
+void init_usterr(void);
+void init_usterr(void)
+{
+	CRIT("Incompatible library ABIs detected within the same process. "
+		"The process is likely linked against different major soname of LTTng-UST which is unsupported. "
+		"The detection was triggered by canary symbol \"%s\"\n", __func__);
+}
+
 /*
  * sessiond monitoring thread: monitor presence of global and per-user
  * sessiond by polling the application common named pipe.
  */
 static
-void lttng_ust_init(void)
+void lttng_ust_ctor(void)
 	__attribute__((constructor));
 static
-void lttng_ust_init(void)
+void lttng_ust_ctor(void)
 {
 	struct timespec constructor_timeout;
 	sigset_t sig_all_blocked, orig_parent_mask;
@@ -2086,14 +2155,22 @@ void lttng_ust_init(void)
 		return;
 
 	/*
-	 * Fixup interdependency between TLS fixup mutex (which happens
+	 * Fixup interdependency between TLS allocation mutex (which happens
 	 * to be the dynamic linker mutex) and ust_lock, taken within
 	 * the ust lock.
 	 */
-	lttng_ust_fixup_tls();
+	lttng_ust_alloc_tls();
 
 	lttng_ust_loaded = 1;
 
+	/*
+	 * Check if we find a symbol of the previous ABI in the current process
+	 * as different ABIs of liblttng-ust can't co-exist in a process. If we
+	 * do so, emit a critical log message which will also abort if the
+	 * LTTNG_UST_ABORT_ON_CRITICAL environment variable is set.
+	 */
+	lttng_ust_check_soname_0();
+
 	/*
 	 * We need to ensure that the liblttng-ust library is not unloaded to avoid
 	 * the unloading of code used by the ust_listener_threads as we can not
@@ -2112,6 +2189,8 @@ void lttng_ust_init(void)
 	handle = dlopen(LTTNG_UST_LIB_SONAME, RTLD_LAZY | RTLD_NODELETE);
 	if (!handle) {
 		ERR("dlopen of liblttng-ust shared library (%s).", LTTNG_UST_LIB_SONAME);
+	} else {
+		DBG("dlopened liblttng-ust shared library (%s).", LTTNG_UST_LIB_SONAME);
 	}
 
 	/*
@@ -2120,12 +2199,21 @@ void lttng_ust_init(void)
 	 * sessiond (otherwise leading to errors when trying to create
 	 * sessiond before the init functions are completed).
 	 */
+
+	/*
+	 * Both the logging and getenv lazy-initialization uses getenv()
+	 * internally and thus needs to be explicitly initialized in
+	 * liblttng-ust before we start any threads as an unsuspecting normally
+	 * single threaded application using liblttng-ust could be using
+	 * setenv() which is not thread-safe.
+	 */
 	lttng_ust_logging_init();
-	lttng_ust_getenv_init();	/* Needs lttng_ust_logging_init() to be completed. */
+	lttng_ust_getenv_init();
+
+	/* Call the liblttng-ust-common constructor. */
+	lttng_ust_common_ctor();
+
 	lttng_ust_tp_init();
-	lttng_ust_init_fd_tracker();
-	lttng_ust_clock_init();
-	lttng_ust_getcpu_plugin_init();
 	lttng_ust_statedump_init();
 	lttng_ust_ring_buffer_clients_init();
 	lttng_ust_counter_clients_init();
@@ -2133,7 +2221,7 @@ void lttng_ust_init(void)
 	/*
 	 * Invoke ust malloc wrapper init before starting other threads.
 	 */
-	lttng_ust_libc_wrapper_malloc_init();
+	lttng_ust_libc_wrapper_malloc_ctor();
 
 	timeout_mode = get_constructor_timeout(&constructor_timeout);
 
@@ -2384,8 +2472,8 @@ void lttng_ust_before_fork(sigset_t *save_sigset)
 	sigset_t all_sigs;
 	int ret;
 
-	/* Fixup lttng-ust TLS. */
-	lttng_ust_fixup_tls();
+	/* Allocate lttng-ust TLS. */
+	lttng_ust_alloc_tls();
 
 	if (URCU_TLS(lttng_ust_nest_count))
 		return;
@@ -2436,7 +2524,7 @@ void lttng_ust_after_fork_parent(sigset_t *restore_sigset)
  * After fork, in the child, we need to cleanup all the leftover state,
  * except the worker thread which already magically disappeared thanks
  * to the weird Linux fork semantics. After tyding up, we call
- * lttng_ust_init() again to start over as a new PID.
+ * lttng_ust_ctor() again to start over as a new PID.
  *
  * This is meant for forks() that have tracing in the child between the
  * fork and following exec call (if there is any).
@@ -2457,7 +2545,7 @@ void lttng_ust_after_fork_child(sigset_t *restore_sigset)
 	lttng_ust_cleanup(0);
 	/* Release mutexes and reenable signals */
 	ust_after_fork_common(restore_sigset);
-	lttng_ust_init();
+	lttng_ust_ctor();
 }
 
 void lttng_ust_after_setns(void)