Implement base-address-state tracing

[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 a6e4ba35c9a68f9dae607d196f6c640f751c2989..77d8e3fcb3564de19100b0a50c080ecba5ba2ad4 100644 (file)
--- a/liblttng-ust/lttng-ust-comm.c
+++ b/liblttng-ust/lttng-ust-comm.c
@@ -34,6 +34,7 @@
 #include <time.h>
 #include <assert.h>
 #include <signal.h>
+#include <dlfcn.h>
 #include <urcu/uatomic.h>
 #include <urcu/futex.h>
 #include <urcu/compiler.h>
@@ -106,6 +107,7 @@ struct sock_info {
 
        char wait_shm_path[PATH_MAX];
        char *wait_shm_mmap;
+       struct lttng_session *session_enabled;
 };
 
 /* Socket from app (connect) to session daemon (listen) for communication */
@@ -122,6 +124,8 @@ struct sock_info global_apps = {
        .notify_socket = -1,
 
        .wait_shm_path = "/" LTTNG_UST_WAIT_FILENAME,
+
+       .session_enabled = NULL,
 };
 
 /* TODO: allow global_apps_sock_path override */
@@ -135,6 +139,8 @@ struct sock_info local_apps = {
 
        .socket = -1,
        .notify_socket = -1,
+
+       .session_enabled = NULL,
 };
 
 static int wait_poll_fallback;
@@ -172,10 +178,12 @@ static const char *cmd_name_mapping[] = {
 
        /* Event FD commands */
        [ LTTNG_UST_FILTER ] = "Create Filter",
+       [ LTTNG_UST_EXCLUSION ] = "Add exclusions to event",
 };
 
 static const char *str_timeout;
 static int got_timeout_env;
+static void *ust_baddr_handle;
 
 extern void lttng_ring_buffer_client_overwrite_init(void);
 extern void lttng_ring_buffer_client_overwrite_rt_init(void);
@@ -234,6 +242,39 @@ void print_cmd(int cmd, int handle)
                lttng_ust_obj_get_name(handle), handle);
 }
 
+static
+void *lttng_ust_baddr_handle(void)
+{
+       if (!ust_baddr_handle) {
+               ust_baddr_handle = dlopen(
+                       "liblttng-ust-baddr.so.0", RTLD_NOW | RTLD_GLOBAL);
+               if (ust_baddr_handle == NULL)
+                       ERR("%s", dlerror());
+       }
+       return ust_baddr_handle;
+}
+
+static
+int lttng_ust_baddr_statedump(struct lttng_session *session)
+{
+       static
+       int (*lttng_ust_baddr_init_fn)(struct lttng_session *);
+
+       if (!lttng_ust_baddr_init_fn) {
+               void *baddr_handle = lttng_ust_baddr_handle();
+               if (baddr_handle) {
+                       lttng_ust_baddr_init_fn = dlsym(baddr_handle,
+                               "lttng_ust_baddr_statedump");
+                       if (lttng_ust_baddr_init_fn == NULL)
+                               ERR("%s", dlerror());
+               }
+               if (!lttng_ust_baddr_init_fn)
+                       return -1;
+       }
+
+       return lttng_ust_baddr_init_fn(session);
+}
+
 static
 int setup_local_apps(void)
 {
@@ -487,6 +528,68 @@ int handle_message(struct sock_info *sock_info,
                }
                break;
        }
+       case LTTNG_UST_EXCLUSION:
+       {
+               /* Receive exclusion names */
+               struct lttng_ust_excluder_node *node;
+               unsigned int count;
+
+               count = lum->u.exclusion.count;
+               if (count == 0) {
+                       /* There are no names to read */
+                       ret = 0;
+                       goto error;
+               }
+               node = zmalloc(sizeof(*node) +
+                               count * LTTNG_UST_SYM_NAME_LEN);
+               if (!node) {
+                       ret = -ENOMEM;
+                       goto error;
+               }
+               node->excluder.count = count;
+               len = ustcomm_recv_unix_sock(sock, node->excluder.names,
+                               count * LTTNG_UST_SYM_NAME_LEN);
+               switch (len) {
+               case 0: /* orderly shutdown */
+                       ret = 0;
+                       free(node);
+                       goto error;
+               default:
+                       if (len == count * LTTNG_UST_SYM_NAME_LEN) {
+                               DBG("Exclusion 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(node);
+                                       goto error;
+                               }
+                               ret = len;
+                               free(node);
+                               goto end;
+                       } else {
+                               DBG("Incorrect exclusion data message size: %zd", len);
+                               ret = -EINVAL;
+                               free(node);
+                               goto end;
+                       }
+               }
+               if (ops->cmd) {
+                       ret = ops->cmd(lum->handle, lum->cmd,
+                                       (unsigned long) node,
+                                       &args, sock_info);
+                       if (ret) {
+                               free(node);
+                       }
+                       /* Don't free exclusion data if everything went fine. */
+               } else {
+                       ret = -ENOSYS;
+                       free(node);
+               }
+               break;
+       }
        case LTTNG_UST_CHANNEL:
        {
                void *chan_data;
@@ -1143,6 +1246,13 @@ restart:
                        ret = handle_message(sock_info, sock, &lum);
                        if (ret) {
                                ERR("Error handling message for %s socket", sock_info->name);
+                       } else {
+                               struct lttng_session *session =
+                                       sock_info->session_enabled;
+                               if (session) {
+                                       sock_info->session_enabled = NULL;
+                                       lttng_ust_baddr_statedump(session);
+                               }
                        }
                        continue;
                default:
@@ -1379,6 +1489,12 @@ void __attribute__((destructor)) lttng_ust_exit(void)
         * cleanup the threads if there are stalled in a syscall.
         */
        lttng_ust_cleanup(1);
+
+       if (ust_baddr_handle) {
+               int ret = dlclose(ust_baddr_handle);
+               if (ret)
+                       ERR("%s", dlerror());
+       }
 }
 
 /*
@@ -1456,3 +1572,10 @@ void ust_after_fork_child(sigset_t *restore_sigset)
        ust_after_fork_common(restore_sigset);
        lttng_ust_init();
 }
+
+void lttng_ust_sockinfo_session_enabled(void *owner,
+               struct lttng_session *session_enabled)
+{
+       struct sock_info *sock_info = owner;
+       sock_info->session_enabled = session_enabled;
+}