int statedump_pending;
int initial_statedump_done;
/* Keep procname for statedump */
- char procname[LTTNG_UST_ABI_PROCNAME_LEN];
+ char procname[LTTNG_UST_CONTEXT_PROCNAME_LEN];
};
/* Socket from app (connect) to session daemon (listen) for communication */
}
global_apps.allowed = 1;
- lttng_pthread_getname_np(global_apps.procname, LTTNG_UST_ABI_PROCNAME_LEN);
+ lttng_pthread_getname_np(global_apps.procname, LTTNG_UST_CONTEXT_PROCNAME_LEN);
error:
return ret;
}
goto end;
}
- lttng_pthread_getname_np(local_apps.procname, LTTNG_UST_ABI_PROCNAME_LEN);
+ lttng_pthread_getname_np(local_apps.procname, LTTNG_UST_CONTEXT_PROCNAME_LEN);
end:
return ret;
}
}
static
-int register_to_sessiond(int socket, enum lttng_ust_ctl_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,
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
}
sock_info->root_handle = -1;
}
- sock_info->registration_done = 0;
- sock_info->initial_statedump_done = 0;
+
/*
* wait_shm_mmap, socket and notify socket are used by listener
if (exiting)
return;
+ sock_info->registration_done = 0;
+ sock_info->initial_statedump_done = 0;
+
if (sock_info->socket != -1) {
ret = ustcomm_close_unix_sock(sock_info->socket);
if (ret) {
sock_info->root_handle = ret;
}
- ret = register_to_sessiond(sock_info->socket, LTTNG_UST_CTL_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);
}
ret = register_to_sessiond(sock_info->notify_socket,
- LTTNG_UST_CTL_SOCKET_NOTIFY);
+ LTTNG_UST_CTL_SOCKET_NOTIFY, sock_info->procname);
if (ret < 0) {
ERR("Error registering to %s ust notify socket",
sock_info->name);
{
}
+/*
+ * 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.
+ *
+ * This scheme will only work on systems where the global symbol table has
+ * priority when resolving the symbols of a dlopened shared object, which is
+ * the case on Linux but not on FreeBSD.
+ */
+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.
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
* 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_SONAME library, calling dlopen will
- * simply increment the refcount and no additionnal work is needed by the
+ * simply increment the refcount and no additional 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
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);
}
/*
return;
DBG("process %d", getpid());
lttng_ust_urcu_after_fork_parent();
- /* Release mutexes and reenable signals */
+ /* Release mutexes and re-enable signals */
ust_after_fork_common(restore_sigset);
}
/* Release urcu mutexes */
lttng_ust_urcu_after_fork_child();
lttng_ust_cleanup(0);
- /* Release mutexes and reenable signals */
+ /* Release mutexes and re-enable signals */
ust_after_fork_common(restore_sigset);
lttng_ust_ctor();
}
projects / lttng-ust.git / blobdiff