{
}
+/*
+ * 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);
}
/*