}
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
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)
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)
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:
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.
+ */
+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
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);
}
/*
projects / lttng-ust.git / blobdiff