X-Git-Url: http://git.lttng.org/?a=blobdiff_plain;f=liblttng-ust%2Flttng-ust-comm.c;h=900a0e840861f78d7a826abc0ed176b0960a0435;hb=fb31eb73d8a4a6d9784ed5c335b7fa3b9684108c;hp=d4add1c07ec9555aa0a35009c7a93a54749c34a7;hpb=06b16a0bab0098e44c4cdffef2e92ed1e5a0abcc;p=lttng-ust.git diff --git a/liblttng-ust/lttng-ust-comm.c b/liblttng-ust/lttng-ust-comm.c index d4add1c0..900a0e84 100644 --- a/liblttng-ust/lttng-ust-comm.c +++ b/liblttng-ust/lttng-ust-comm.c @@ -21,6 +21,8 @@ #define _LGPL_SOURCE #define _GNU_SOURCE +#include +#include #include #include #include @@ -61,7 +63,7 @@ #include "getenv.h" /* Concatenate lttng ust shared library name with its major version number. */ -#define LTTNG_UST_LIB_SO_NAME "liblttng-ust.so." LTTNG_UST_LIBRARY_VERSION_MAJOR +#define LTTNG_UST_LIB_SO_NAME "liblttng-ust.so." __ust_stringify(CONFIG_LTTNG_UST_LIBRARY_VERSION_MAJOR) /* * Has lttng ust comm constructor been called ? @@ -86,6 +88,8 @@ static int initialized; * * ust_lock nests within the dynamic loader lock (within glibc) because * it is taken within the library constructor. + * + * The ust fd tracker lock nests within the ust_mutex. */ static pthread_mutex_t ust_mutex = PTHREAD_MUTEX_INITIALIZER; @@ -228,7 +232,11 @@ static sem_t constructor_wait; /* * Doing this for both the global and local sessiond. */ -static int sem_count = { 2 }; +enum { + sem_count_initial_value = 4, +}; + +static int sem_count = sem_count_initial_value; /* * Counting nesting within lttng-ust. Used to ensure that calling fork() @@ -243,7 +251,7 @@ struct sock_info { const char *name; pthread_t ust_listener; /* listener thread */ int root_handle; - int constructor_sem_posted; + int registration_done; int allowed; int global; int thread_active; @@ -256,6 +264,9 @@ struct sock_info { char *wait_shm_mmap; /* Keep track of lazy state dump not performed yet. */ int statedump_pending; + int initial_statedump_done; + /* Keep procname for statedump */ + char procname[LTTNG_UST_PROCNAME_LEN]; }; /* Socket from app (connect) to session daemon (listen) for communication */ @@ -264,7 +275,8 @@ struct sock_info global_apps = { .global = 1, .root_handle = -1, - .allowed = 1, + .registration_done = 0, + .allowed = 0, .thread_active = 0, .sock_path = LTTNG_DEFAULT_RUNDIR "/" LTTNG_UST_SOCK_FILENAME, @@ -274,6 +286,8 @@ struct sock_info global_apps = { .wait_shm_path = "/" LTTNG_UST_WAIT_FILENAME, .statedump_pending = 0, + .initial_statedump_done = 0, + .procname[0] = '\0' }; /* TODO: allow global_apps_sock_path override */ @@ -282,6 +296,7 @@ struct sock_info local_apps = { .name = "local", .global = 0, .root_handle = -1, + .registration_done = 0, .allowed = 0, /* Check setuid bit first */ .thread_active = 0, @@ -289,6 +304,8 @@ struct sock_info local_apps = { .notify_socket = -1, .statedump_pending = 0, + .initial_statedump_done = 0, + .procname[0] = '\0' }; static int wait_poll_fallback; @@ -343,6 +360,8 @@ extern void lttng_ring_buffer_client_discard_exit(void); extern void lttng_ring_buffer_client_discard_rt_exit(void); extern void lttng_ring_buffer_metadata_client_exit(void); +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; @@ -410,7 +429,12 @@ void lttng_ust_fixup_tls(void) 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_uts_ns_tls(); } int lttng_get_notify_socket(void *owner) @@ -420,6 +444,15 @@ int lttng_get_notify_socket(void *owner) return info->notify_socket; } + +LTTNG_HIDDEN +char* lttng_ust_sockinfo_get_procname(void *owner) +{ + struct sock_info *info = owner; + + return info->procname; +} + static void print_cmd(int cmd, int handle) { @@ -434,25 +467,49 @@ void print_cmd(int cmd, int handle) lttng_ust_obj_get_name(handle), handle); } +static +int setup_global_apps(void) +{ + int ret = 0; + assert(!global_apps.wait_shm_mmap); + + global_apps.wait_shm_mmap = get_map_shm(&global_apps); + if (!global_apps.wait_shm_mmap) { + WARN("Unable to get map shm for global apps. Disabling LTTng-UST global tracing."); + global_apps.allowed = 0; + ret = -EIO; + goto error; + } + + global_apps.allowed = 1; + lttng_ust_getprocname(global_apps.procname); +error: + return ret; +} static int setup_local_apps(void) { + int ret = 0; const char *home_dir; uid_t uid; + assert(!local_apps.wait_shm_mmap); + uid = getuid(); /* * Disallow per-user tracing for setuid binaries. */ if (uid != geteuid()) { assert(local_apps.allowed == 0); - return 0; + ret = 0; + goto end; } home_dir = get_lttng_home_dir(); if (!home_dir) { WARN("HOME environment variable not set. Disabling LTTng-UST per-user tracing."); assert(local_apps.allowed == 0); - return -ENOENT; + ret = -ENOENT; + goto end; } local_apps.allowed = 1; snprintf(local_apps.sock_path, PATH_MAX, "%s/%s/%s", @@ -462,7 +519,18 @@ int setup_local_apps(void) snprintf(local_apps.wait_shm_path, PATH_MAX, "/%s-%u", LTTNG_UST_WAIT_FILENAME, uid); - return 0; + + local_apps.wait_shm_mmap = get_map_shm(&local_apps); + if (!local_apps.wait_shm_mmap) { + WARN("Unable to get map shm for local apps. Disabling LTTng-UST per-user tracing."); + local_apps.allowed = 0; + ret = -EIO; + goto end; + } + + lttng_ust_getprocname(local_apps.procname); +end: + return ret; } /* @@ -587,45 +655,85 @@ int send_reply(int sock, struct ustcomm_ust_reply *lur) } static -int handle_register_done(struct sock_info *sock_info) +void decrement_sem_count(unsigned int count) { int ret; - if (sock_info->constructor_sem_posted) - return 0; - sock_info->constructor_sem_posted = 1; + assert(uatomic_read(&sem_count) >= count); + if (uatomic_read(&sem_count) <= 0) { - return 0; + return; } - ret = uatomic_add_return(&sem_count, -1); + + ret = uatomic_add_return(&sem_count, -count); if (ret == 0) { ret = sem_post(&constructor_wait); assert(!ret); } +} + +static +int handle_register_done(struct sock_info *sock_info) +{ + if (sock_info->registration_done) + return 0; + sock_info->registration_done = 1; + + decrement_sem_count(1); + if (!sock_info->statedump_pending) { + sock_info->initial_statedump_done = 1; + decrement_sem_count(1); + } + + return 0; +} + +static +int handle_register_failed(struct sock_info *sock_info) +{ + if (sock_info->registration_done) + return 0; + sock_info->registration_done = 1; + sock_info->initial_statedump_done = 1; + + decrement_sem_count(2); + return 0; } /* * Only execute pending statedump after the constructor semaphore has - * been posted by each listener thread. This means statedump will only - * be performed after the "registration done" command is received from - * each session daemon the application is connected to. + * been posted by the current listener thread. This means statedump will + * only be performed after the "registration done" command is received + * from this thread's session daemon. * * This ensures we don't run into deadlock issues with the dynamic * loader mutex, which is held while the constructor is called and * waiting on the constructor semaphore. All operations requiring this * dynamic loader lock need to be postponed using this mechanism. + * + * In a scenario with two session daemons connected to the application, + * it is possible that the first listener thread which receives the + * registration done command issues its statedump while the dynamic + * loader lock is still held by the application constructor waiting on + * the semaphore. It will however be allowed to proceed when the + * second session daemon sends the registration done command to the + * second listener thread. This situation therefore does not produce + * a deadlock. */ static void handle_pending_statedump(struct sock_info *sock_info) { - int ctor_passed = sock_info->constructor_sem_posted; - - if (ctor_passed && sock_info->statedump_pending) { + if (sock_info->registration_done && sock_info->statedump_pending) { sock_info->statedump_pending = 0; pthread_mutex_lock(&ust_fork_mutex); lttng_handle_pending_statedump(sock_info); pthread_mutex_unlock(&ust_fork_mutex); + + if (!sock_info->initial_statedump_done) { + sock_info->initial_statedump_done = 1; + decrement_sem_count(1); + } } } @@ -843,12 +951,13 @@ int handle_message(struct sock_info *sock_info, { /* Receive shm_fd, wakeup_fd */ ret = ustcomm_recv_stream_from_sessiond(sock, - &lum->u.stream.len, + NULL, &args.stream.shm_fd, &args.stream.wakeup_fd); if (ret) { goto error; } + if (ops->cmd) ret = ops->cmd(lum->handle, lum->cmd, (unsigned long) &lum->u, @@ -1034,7 +1143,8 @@ void cleanup_sock_info(struct sock_info *sock_info, int exiting) } sock_info->root_handle = -1; } - sock_info->constructor_sem_posted = 0; + sock_info->registration_done = 0; + sock_info->initial_statedump_done = 0; /* * wait_shm_mmap, socket and notify socket are used by listener @@ -1305,19 +1415,17 @@ error: static void wait_for_sessiond(struct sock_info *sock_info) { + /* Use ust_lock to check if we should quit. */ if (ust_lock()) { goto quit; } if (wait_poll_fallback) { goto error; } - if (!sock_info->wait_shm_mmap) { - sock_info->wait_shm_mmap = get_map_shm(sock_info); - if (!sock_info->wait_shm_mmap) - goto error; - } ust_unlock(); + assert(sock_info->wait_shm_mmap); + DBG("Waiting for %s apps sessiond", sock_info->name); /* Wait for futex wakeup */ if (uatomic_read((int32_t *) sock_info->wait_shm_mmap)) @@ -1444,7 +1552,7 @@ restart: * If we cannot find the sessiond daemon, don't delay * constructor execution. */ - ret = handle_register_done(sock_info); + ret = handle_register_failed(sock_info); assert(!ret); ust_unlock(); goto restart; @@ -1498,7 +1606,7 @@ restart: * If we cannot register to the sessiond daemon, don't * delay constructor execution. */ - ret = handle_register_done(sock_info); + ret = handle_register_failed(sock_info); assert(!ret); ust_unlock(); goto restart; @@ -1527,7 +1635,7 @@ restart: * If we cannot find the sessiond daemon, don't delay * constructor execution. */ - ret = handle_register_done(sock_info); + ret = handle_register_failed(sock_info); assert(!ret); ust_unlock(); goto restart; @@ -1591,7 +1699,7 @@ restart: * If we cannot register to the sessiond daemon, don't * delay constructor execution. */ - ret = handle_register_done(sock_info); + ret = handle_register_failed(sock_info); assert(!ret); ust_unlock(); goto restart; @@ -1621,7 +1729,7 @@ restart: * If we cannot register to the sessiond daemon, don't * delay constructor execution. */ - ret = handle_register_done(sock_info); + ret = handle_register_failed(sock_info); assert(!ret); ust_unlock(); goto end; @@ -1756,8 +1864,15 @@ void __attribute__((constructor)) lttng_ust_init(void) PERROR("sem_init"); } + ret = setup_global_apps(); + if (ret) { + assert(global_apps.allowed == 0); + DBG("global apps setup returned %d", ret); + } + ret = setup_local_apps(); if (ret) { + assert(local_apps.allowed == 0); DBG("local apps setup returned %d", ret); } @@ -1781,14 +1896,18 @@ void __attribute__((constructor)) lttng_ust_init(void) ERR("pthread_attr_setdetachstate: %s", strerror(ret)); } - pthread_mutex_lock(&ust_exit_mutex); - ret = pthread_create(&global_apps.ust_listener, &thread_attr, - ust_listener_thread, &global_apps); - if (ret) { - ERR("pthread_create global: %s", strerror(ret)); + if (global_apps.allowed) { + pthread_mutex_lock(&ust_exit_mutex); + ret = pthread_create(&global_apps.ust_listener, &thread_attr, + ust_listener_thread, &global_apps); + if (ret) { + ERR("pthread_create global: %s", strerror(ret)); + } + global_apps.thread_active = 1; + pthread_mutex_unlock(&ust_exit_mutex); + } else { + handle_register_done(&global_apps); } - global_apps.thread_active = 1; - pthread_mutex_unlock(&ust_exit_mutex); if (local_apps.allowed) { pthread_mutex_lock(&ust_exit_mutex); @@ -1859,6 +1978,7 @@ void lttng_ust_cleanup(int exiting) cleanup_sock_info(&global_apps, exiting); cleanup_sock_info(&local_apps, exiting); local_apps.allowed = 0; + global_apps.allowed = 0; /* * The teardown in this function all affect data structures * accessed under the UST lock by the listener thread. This @@ -1878,7 +1998,7 @@ void lttng_ust_cleanup(int exiting) exit_tracepoint(); if (!exiting) { /* Reinitialize values for fork */ - sem_count = 2; + sem_count = sem_count_initial_value; lttng_ust_comm_should_quit = 0; initialized = 0; } @@ -1936,6 +2056,34 @@ void __attribute__((destructor)) lttng_ust_exit(void) lttng_ust_cleanup(1); } +static +void ust_context_ns_reset(void) +{ + lttng_context_pid_ns_reset(); + lttng_context_cgroup_ns_reset(); + lttng_context_ipc_ns_reset(); + lttng_context_mnt_ns_reset(); + lttng_context_net_ns_reset(); + lttng_context_user_ns_reset(); + lttng_context_uts_ns_reset(); +} + +static +void ust_context_vuids_reset(void) +{ + lttng_context_vuid_reset(); + lttng_context_veuid_reset(); + lttng_context_vsuid_reset(); +} + +static +void ust_context_vgids_reset(void) +{ + lttng_context_vgid_reset(); + lttng_context_vegid_reset(); + lttng_context_vsgid_reset(); +} + /* * We exclude the worker threads across fork and clone (except * CLONE_VM), because these system calls only keep the forking thread @@ -1969,7 +2117,9 @@ void ust_before_fork(sigset_t *save_sigset) pthread_mutex_lock(&ust_fork_mutex); ust_lock_nocheck(); - rcu_bp_before_fork(); + urcu_bp_before_fork(); + lttng_ust_lock_fd_tracker(); + lttng_perf_lock(); } static void ust_after_fork_common(sigset_t *restore_sigset) @@ -1977,6 +2127,8 @@ static void ust_after_fork_common(sigset_t *restore_sigset) int ret; DBG("process %d", getpid()); + lttng_perf_unlock(); + lttng_ust_unlock_fd_tracker(); ust_unlock(); pthread_mutex_unlock(&ust_fork_mutex); @@ -1993,7 +2145,7 @@ void ust_after_fork_parent(sigset_t *restore_sigset) if (URCU_TLS(lttng_ust_nest_count)) return; DBG("process %d", getpid()); - rcu_bp_after_fork_parent(); + urcu_bp_after_fork_parent(); /* Release mutexes and reenable signals */ ust_after_fork_common(restore_sigset); } @@ -2013,15 +2165,73 @@ void ust_after_fork_child(sigset_t *restore_sigset) return; lttng_context_vpid_reset(); lttng_context_vtid_reset(); + lttng_context_procname_reset(); + ust_context_ns_reset(); + ust_context_vuids_reset(); + ust_context_vgids_reset(); DBG("process %d", getpid()); /* Release urcu mutexes */ - rcu_bp_after_fork_child(); + urcu_bp_after_fork_child(); lttng_ust_cleanup(0); /* Release mutexes and reenable signals */ ust_after_fork_common(restore_sigset); lttng_ust_init(); } +void ust_after_setns(void) +{ + ust_context_ns_reset(); + ust_context_vuids_reset(); + ust_context_vgids_reset(); +} + +void ust_after_unshare(void) +{ + ust_context_ns_reset(); + ust_context_vuids_reset(); + ust_context_vgids_reset(); +} + +void ust_after_setuid(void) +{ + ust_context_vuids_reset(); +} + +void ust_after_seteuid(void) +{ + ust_context_vuids_reset(); +} + +void ust_after_setreuid(void) +{ + ust_context_vuids_reset(); +} + +void ust_after_setresuid(void) +{ + ust_context_vuids_reset(); +} + +void ust_after_setgid(void) +{ + ust_context_vgids_reset(); +} + +void ust_after_setegid(void) +{ + ust_context_vgids_reset(); +} + +void ust_after_setregid(void) +{ + ust_context_vgids_reset(); +} + +void ust_after_setresgid(void) +{ + ust_context_vgids_reset(); +} + void lttng_ust_sockinfo_session_enabled(void *owner) { struct sock_info *sock_info = owner;