static int opt_python;
static int opt_enable_all;
static char *opt_probe;
+static char *opt_userspace_probe;
static char *opt_function;
static char *opt_channel_name;
static char *opt_filter;
OPT_HELP = 1,
OPT_TRACEPOINT,
OPT_PROBE,
+ OPT_USERSPACE_PROBE,
OPT_FUNCTION,
OPT_SYSCALL,
OPT_USERSPACE,
{"python", 'p', POPT_ARG_VAL, &opt_python, 1, 0, 0},
{"tracepoint", 0, POPT_ARG_NONE, 0, OPT_TRACEPOINT, 0, 0},
{"probe", 0, POPT_ARG_STRING, &opt_probe, OPT_PROBE, 0, 0},
+ {"userspace-probe",0, POPT_ARG_STRING, &opt_userspace_probe, OPT_USERSPACE_PROBE, 0, 0},
{"function", 0, POPT_ARG_STRING, &opt_function, OPT_FUNCTION, 0, 0},
{"syscall", 0, POPT_ARG_NONE, 0, OPT_SYSCALL, 0, 0},
{"loglevel", 0, POPT_ARG_STRING, 0, OPT_LOGLEVEL, 0, 0},
return ret;
}
+/*
+ * Check if the symbol field passed by the user is in fact an address or an
+ * offset from a symbol. Those two instrumentation types are not supported yet.
+ * It's expected to be a common mistake because of the existing --probe option
+ * that does support these formats.
+ *
+ * Here are examples of these unsupported formats for the --userspace-probe
+ * option:
+ * elf:/path/to/binary:0x400430
+ * elf:/path/to/binary:4194364
+ * elf:/path/to/binary:my_symbol+0x323
+ * elf:/path/to/binary:my_symbol+43
+ */
+static int warn_userspace_probe_syntax(const char *symbol)
+{
+ int ret;
+
+ /* Check if the symbol field is an hex address. */
+ ret = sscanf(symbol, "0x%*x");
+ if (ret > 0) {
+ /* If there is a match, print a warning and return an error. */
+ ERR("Userspace probe on address not supported yet.");
+ ret = CMD_UNSUPPORTED;
+ goto error;
+ }
+
+ /* Check if the symbol field is an decimal address. */
+ ret = sscanf(symbol, "%*u");
+ if (ret > 0) {
+ /* If there is a match, print a warning and return an error. */
+ ERR("Userspace probe on address not supported yet.");
+ ret = CMD_UNSUPPORTED;
+ goto error;
+ }
+
+ /* Check if the symbol field is symbol+hex_offset. */
+ ret = sscanf(symbol, "%*[^+]+0x%*x");
+ if (ret > 0) {
+ /* If there is a match, print a warning and return an error. */
+ ERR("Userspace probe on symbol+offset not supported yet.");
+ ret = CMD_UNSUPPORTED;
+ goto error;
+ }
+
+ /* Check if the symbol field is symbol+decimal_offset. */
+ ret = sscanf(symbol, "%*[^+]+%*u");
+ if (ret > 0) {
+ /* If there is a match, print a warning and return an error. */
+ ERR("Userspace probe on symbol+offset not supported yet.");
+ ret = CMD_UNSUPPORTED;
+ goto error;
+ }
+
+ ret = 0;
+
+error:
+ return ret;
+}
+
+/*
+ * Parse userspace probe options
+ * Set the userspace probe fields in the lttng_event struct and set the
+ * target_path to the path to the binary.
+ */
+static int parse_userspace_probe_opts(struct lttng_event *ev, char *opt)
+{
+ int ret = CMD_SUCCESS;
+ int num_token;
+ char **tokens;
+ char *target_path = NULL;
+ char *unescaped_target_path = NULL;
+ char *real_target_path = NULL;
+ char *symbol_name = NULL, *probe_name = NULL, *provider_name = NULL;
+ struct lttng_userspace_probe_location *probe_location = NULL;
+ struct lttng_userspace_probe_location_lookup_method *lookup_method =
+ NULL;
+
+ if (opt == NULL) {
+ ret = CMD_ERROR;
+ goto end;
+ }
+
+ switch (ev->type) {
+ case LTTNG_EVENT_USERSPACE_PROBE:
+ break;
+ default:
+ assert(0);
+ }
+
+ /*
+ * userspace probe fields are separated by ':'.
+ */
+ tokens = strutils_split(opt, ':', 1);
+ num_token = strutils_array_of_strings_len(tokens);
+
+ /*
+ * Early sanity check that the number of parameter is between 2 and 4
+ * inclusively.
+ * elf:PATH:SYMBOL
+ * std:PATH:PROVIDER_NAME:PROBE_NAME
+ * PATH:SYMBOL (same behavior as ELF)
+ */
+ if (num_token < 2 || num_token > 4) {
+ ret = CMD_ERROR;
+ goto end_string;
+ }
+
+ /*
+ * Looking up the first parameter will tell the technique to use to
+ * interpret the userspace probe/function description.
+ */
+ switch (num_token) {
+ case 2:
+ /* When the probe type is omitted we assume ELF for now. */
+ case 3:
+ if (num_token == 3 && strcmp(tokens[0], "elf") == 0) {
+ target_path = tokens[1];
+ symbol_name = tokens[2];
+ } else if (num_token == 2) {
+ target_path = tokens[0];
+ symbol_name = tokens[1];
+ } else {
+ ret = CMD_ERROR;
+ goto end_string;
+ }
+ lookup_method =
+ lttng_userspace_probe_location_lookup_method_function_elf_create();
+ if (!lookup_method) {
+ WARN("Failed to create ELF lookup method");
+ ret = CMD_ERROR;
+ goto end_string;
+ }
+ break;
+ case 4:
+ if (strcmp(tokens[0], "sdt") == 0) {
+ target_path = tokens[1];
+ provider_name = tokens[2];
+ probe_name = tokens[3];
+ } else {
+ ret = CMD_ERROR;
+ goto end_string;
+ }
+ lookup_method =
+ lttng_userspace_probe_location_lookup_method_tracepoint_sdt_create();
+ if (!lookup_method) {
+ WARN("Failed to create ELF lookup method");
+ ret = CMD_ERROR;
+ goto end_string;
+ }
+ break;
+ default:
+ ret = CMD_ERROR;
+ goto end_string;
+ }
+
+ /* strutils_unescape_string allocates a new char *. */
+ unescaped_target_path = strutils_unescape_string(target_path, 0);
+ if (!unescaped_target_path) {
+ ret = CMD_ERROR;
+ goto end_destroy_lookup_method;
+ }
+
+ /*
+ * If there is not forward slash in the path. Walk the $PATH else
+ * expand.
+ */
+ if (strchr(unescaped_target_path, '/') == NULL) {
+ /* Walk the $PATH variable to find the targeted binary. */
+ real_target_path = zmalloc(LTTNG_PATH_MAX * sizeof(char));
+ if (!real_target_path) {
+ PERROR("Error allocating path buffer");
+ ret = CMD_ERROR;
+ goto end_destroy_lookup_method;
+ }
+ ret = walk_command_search_path(unescaped_target_path, real_target_path);
+ if (ret) {
+ ERR("Binary not found.");
+ ret = CMD_ERROR;
+ goto end_destroy_lookup_method;
+ }
+ } else {
+ /*
+ * Expand references to `/./` and `/../`. This function does not check
+ * if the file exists. This call returns an allocated buffer on
+ * success.
+ */
+ real_target_path = utils_expand_path_keep_symlink(unescaped_target_path);
+ if (!real_target_path) {
+ ERR("Error expanding the path to binary.");
+ ret = CMD_ERROR;
+ goto end_destroy_lookup_method;
+ }
+
+ /*
+ * Check if the file exists using access(2). If it does not, walk the
+ * $PATH.
+ */
+ ret = access(real_target_path, F_OK);
+ if (ret) {
+ ERR("Cannot find binary at path: %s.", real_target_path);
+ ret = CMD_ERROR;
+ goto end_destroy_lookup_method;
+ }
+ }
+
+ switch (lttng_userspace_probe_location_lookup_method_get_type(lookup_method)) {
+ case LTTNG_USERSPACE_PROBE_LOCATION_LOOKUP_METHOD_TYPE_FUNCTION_ELF:
+ /*
+ * Check for common mistakes in userspace probe description syntax.
+ */
+ ret = warn_userspace_probe_syntax(symbol_name);
+ if (ret) {
+ goto end_destroy_lookup_method;
+ }
+
+ probe_location = lttng_userspace_probe_location_function_create(
+ real_target_path, symbol_name, lookup_method);
+ if (!probe_location) {
+ WARN("Failed to create function probe location");
+ ret = CMD_ERROR;
+ goto end_destroy_lookup_method;
+ }
+
+ /* Ownership transferred to probe_location. */
+ lookup_method = NULL;
+
+ ret = lttng_event_set_userspace_probe_location(ev, probe_location);
+ if (ret) {
+ WARN("Failed to set probe location on event");
+ ret = CMD_ERROR;
+ goto end_destroy_location;
+ }
+ break;
+ case LTTNG_USERSPACE_PROBE_LOCATION_LOOKUP_METHOD_TYPE_TRACEPOINT_SDT:
+ probe_location = lttng_userspace_probe_location_tracepoint_create(
+ real_target_path, provider_name, probe_name, lookup_method);
+ if (!probe_location) {
+ WARN("Failed to create function probe location");
+ ret = CMD_ERROR;
+ goto end_destroy_lookup_method;
+ }
+
+ /* Ownership transferred to probe_location. */
+ lookup_method = NULL;
+
+ ret = lttng_event_set_userspace_probe_location(ev, probe_location);
+ if (ret) {
+ WARN("Failed to set probe location on event");
+ ret = CMD_ERROR;
+ goto end_destroy_location;
+ }
+ break;
+ default:
+ ret = CMD_ERROR;
+ goto end_destroy_lookup_method;
+ }
+
+ /* Successful parsing, now clean up everything and return. */
+ goto end_string;
+
+end_destroy_location:
+ lttng_userspace_probe_location_destroy(probe_location);
+end_destroy_lookup_method:
+ lttng_userspace_probe_location_lookup_method_destroy(lookup_method);
+end_string:
+ strutils_free_null_terminated_array_of_strings(tokens);
+ /*
+ * Freeing both char * here makes the error handling simplier. free()
+ * performs not action if the pointer is NULL.
+ */
+ free(real_target_path);
+ free(unescaped_target_path);
+end:
+ return ret;
+}
+
/*
* Maps LOG4j loglevel from string to value
*/
}
}
+ /*
+ * Adding a filter to a probe, function or userspace-probe would be
+ * denied by the kernel tracer as it's not supported at the moment. We
+ * do an early check here to warn the user.
+ */
+ if (opt_filter && opt_kernel) {
+ switch (opt_event_type) {
+ case LTTNG_EVENT_ALL:
+ case LTTNG_EVENT_TRACEPOINT:
+ case LTTNG_EVENT_SYSCALL:
+ break;
+ case LTTNG_EVENT_PROBE:
+ case LTTNG_EVENT_USERSPACE_PROBE:
+ case LTTNG_EVENT_FUNCTION:
+ ERR("Filter expressions are not supported for %s events",
+ get_event_type_str(opt_event_type));
+ ret = CMD_ERROR;
+ goto error;
+ default:
+ ret = CMD_UNDEFINED;
+ goto error;
+ }
+ }
+
channel_name = opt_channel_name;
handle = lttng_create_handle(session_name, &dom);
goto error;
}
break;
+ case LTTNG_EVENT_USERSPACE_PROBE:
+ ret = parse_userspace_probe_opts(ev, opt_userspace_probe);
+ if (ret) {
+ switch (ret) {
+ case CMD_UNSUPPORTED:
+ /*
+ * Error message describing
+ * what is not supported was
+ * printed in the function.
+ */
+ break;
+ case CMD_ERROR:
+ default:
+ ERR("Unable to parse userspace probe options");
+ break;
+ }
+ goto error;
+ }
+ break;
case LTTNG_EVENT_FUNCTION:
ret = parse_probe_opts(ev, opt_function);
if (ret) {
case LTTNG_EVENT_PROBE:
case LTTNG_EVENT_FUNCTION:
case LTTNG_EVENT_SYSCALL:
+ case LTTNG_EVENT_USERSPACE_PROBE:
default:
ERR("Event type not available for user-space tracing");
ret = CMD_UNSUPPORTED;
error = 1;
break;
}
+ case LTTNG_ERR_SDT_PROBE_SEMAPHORE:
+ ERR("SDT probes %s guarded by semaphores are not supported (channel %s, session %s)",
+ event_name, print_channel_name(channel_name),
+ session_name);
+ error = 1;
+ break;
default:
ERR("Event %s%s: %s (channel %s, session %s)", event_name,
exclusion_string,
case OPT_PROBE:
opt_event_type = LTTNG_EVENT_PROBE;
break;
+ case OPT_USERSPACE_PROBE:
+ opt_event_type = LTTNG_EVENT_USERSPACE_PROBE;
+ break;
case OPT_FUNCTION:
opt_event_type = LTTNG_EVENT_FUNCTION;
break;
projects / lttng-tools.git / blobdiff