X-Git-Url: http://git.liburcu.org/?a=blobdiff_plain;f=liblttng-ust%2Flttng-ust-comm.c;h=d4add1c07ec9555aa0a35009c7a93a54749c34a7;hb=06b16a0bab0098e44c4cdffef2e92ed1e5a0abcc;hp=651d2aaa45cec437cabb7cdb4147d66330800065;hpb=6f97f9c2bbc74605e3de2b05333ecf25fa52d6fc;p=lttng-ust.git diff --git a/liblttng-ust/lttng-ust-comm.c b/liblttng-ust/lttng-ust-comm.c index 651d2aaa..d4add1c0 100644 --- a/liblttng-ust/lttng-ust-comm.c +++ b/liblttng-ust/lttng-ust-comm.c @@ -27,6 +27,7 @@ #include #include #include +#include #include #include #include @@ -59,6 +60,9 @@ #include "../libringbuffer/getcpu.h" #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 + /* * Has lttng ust comm constructor been called ? */ @@ -366,11 +370,11 @@ const char *get_lttng_home_dir(void) { const char *val; - val = (const char *) lttng_secure_getenv("LTTNG_HOME"); + val = (const char *) lttng_getenv("LTTNG_HOME"); if (val != NULL) { return val; } - return (const char *) lttng_secure_getenv("HOME"); + return (const char *) lttng_getenv("HOME"); } /* @@ -471,7 +475,7 @@ long get_timeout(void) long constructor_delay_ms = LTTNG_UST_DEFAULT_CONSTRUCTOR_TIMEOUT_MS; if (!got_timeout_env) { - str_timeout = getenv("LTTNG_UST_REGISTER_TIMEOUT"); + str_timeout = lttng_getenv("LTTNG_UST_REGISTER_TIMEOUT"); got_timeout_env = 1; } if (str_timeout) @@ -535,26 +539,15 @@ int get_constructor_timeout(struct timespec *constructor_timeout) } static -void get_blocking_retry_timeout(void) +void get_allow_blocking(void) { - const char *str_blocking_retry_timeout = - lttng_secure_getenv("LTTNG_UST_BLOCKING_RETRY_TIMEOUT"); - - if (str_blocking_retry_timeout) { - long timeout = strtol(str_blocking_retry_timeout, NULL, 10); - - if (timeout < 0) - timeout = -1; - if (timeout > INT_MAX) { - WARN("Saturating %s value from %ld to %d\n", - "LTTNG_UST_BLOCKING_RETRY_TIMEOUT", - timeout, INT_MAX); - timeout = INT_MAX; - } - DBG("%s environment variable value is %ld", - "LTTNG_UST_BLOCKING_RETRY_TIMEOUT", - timeout); - lttng_ust_ringbuffer_set_retry_timeout(timeout); + const char *str_allow_blocking = + lttng_getenv("LTTNG_UST_ALLOW_BLOCKING"); + + if (str_allow_blocking) { + DBG("%s environment variable is set", + "LTTNG_UST_ALLOW_BLOCKING"); + lttng_ust_ringbuffer_set_allow_blocking(); } } @@ -1272,7 +1265,18 @@ char *get_map_shm(struct sock_info *sock_info) lttng_ust_unlock_fd_tracker(); goto error; } - lttng_ust_add_fd_to_tracker(wait_shm_fd); + + ret = lttng_ust_add_fd_to_tracker(wait_shm_fd); + if (ret < 0) { + ret = close(wait_shm_fd); + if (!ret) { + PERROR("Error closing fd"); + } + lttng_ust_unlock_fd_tracker(); + goto error; + } + + wait_shm_fd = ret; lttng_ust_unlock_fd_tracker(); wait_shm_mmap = mmap(NULL, page_size, PROT_READ, @@ -1364,7 +1368,7 @@ static void *ust_listener_thread(void *arg) { struct sock_info *sock_info = arg; - int sock, ret, prev_connect_failed = 0, has_waited = 0; + int sock, ret, prev_connect_failed = 0, has_waited = 0, fd; long timeout; lttng_ust_fixup_tls(); @@ -1396,6 +1400,10 @@ restart: prev_connect_failed = 0; } + if (ust_lock()) { + goto quit; + } + if (sock_info->socket != -1) { /* FD tracker is updated by ustcomm_close_unix_sock() */ ret = ustcomm_close_unix_sock(sock_info->socket); @@ -1415,9 +1423,6 @@ restart: sock_info->notify_socket = -1; } - if (ust_lock()) { - goto quit; - } /* * Register. We need to perform both connect and sending @@ -1444,9 +1449,21 @@ restart: ust_unlock(); goto restart; } - lttng_ust_add_fd_to_tracker(ret); - lttng_ust_unlock_fd_tracker(); + fd = ret; + ret = lttng_ust_add_fd_to_tracker(fd); + if (ret < 0) { + ret = close(fd); + if (ret) { + PERROR("close on sock_info->socket"); + } + ret = -1; + lttng_ust_unlock_fd_tracker(); + ust_unlock(); + goto quit; + } + sock_info->socket = ret; + lttng_ust_unlock_fd_tracker(); ust_unlock(); /* @@ -1515,9 +1532,22 @@ restart: ust_unlock(); goto restart; } - lttng_ust_add_fd_to_tracker(ret); - lttng_ust_unlock_fd_tracker(); + + fd = ret; + ret = lttng_ust_add_fd_to_tracker(fd); + if (ret < 0) { + ret = close(fd); + if (ret) { + PERROR("close on sock_info->notify_socket"); + } + ret = -1; + lttng_ust_unlock_fd_tracker(); + ust_unlock(); + goto quit; + } + sock_info->notify_socket = ret; + lttng_ust_unlock_fd_tracker(); ust_unlock(); /* @@ -1659,6 +1689,7 @@ void __attribute__((constructor)) lttng_ust_init(void) pthread_attr_t thread_attr; int timeout_mode; int ret; + void *handle; if (uatomic_xchg(&initialized, 1) == 1) return; @@ -1672,6 +1703,26 @@ void __attribute__((constructor)) lttng_ust_init(void) lttng_ust_loaded = 1; + /* + * 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 + * reliably know when they exited. To do that, manually load + * liblttng-ust.so to increment the dynamic loader's internal refcount for + * this library so it never becomes zero, thus never gets unloaded from the + * address space of the process. Since we are already running in the + * constructor of the LTTNG_UST_LIB_SO_NAME library, calling dlopen will + * simply increment the refcount and no additionnal work is needed by the + * dynamic loader as the shared library is already loaded in the address + * space. As a safe guard, we use the RTLD_NODELETE flag to prevent + * unloading of the UST library if its refcount becomes zero (which should + * never happen). Do the return value check but discard the handle at the + * end of the function as it's not needed. + */ + handle = dlopen(LTTNG_UST_LIB_SO_NAME, RTLD_LAZY | RTLD_NODELETE); + if (!handle) { + ERR("dlopen of liblttng-ust shared library (%s).", LTTNG_UST_LIB_SO_NAME); + } + /* * We want precise control over the order in which we construct * our sub-libraries vs starting to receive commands from @@ -1679,6 +1730,7 @@ void __attribute__((constructor)) lttng_ust_init(void) * sessiond before the init functions are completed). */ init_usterr(); + lttng_ust_getenv_init(); /* Needs init_usterr() to be completed. */ init_tracepoint(); lttng_ust_init_fd_tracker(); lttng_ust_clock_init(); @@ -1697,7 +1749,7 @@ void __attribute__((constructor)) lttng_ust_init(void) timeout_mode = get_constructor_timeout(&constructor_timeout); - get_blocking_retry_timeout(); + get_allow_blocking(); ret = sem_init(&constructor_wait, 0, 0); if (ret) { @@ -1959,6 +2011,7 @@ void ust_after_fork_child(sigset_t *restore_sigset) { if (URCU_TLS(lttng_ust_nest_count)) return; + lttng_context_vpid_reset(); lttng_context_vtid_reset(); DBG("process %d", getpid()); /* Release urcu mutexes */