X-Git-Url: https://git.lttng.org/?p=lttng-tools.git;a=blobdiff_plain;f=src%2Fbin%2Flttng%2Fcommands%2Fenable_events.c;h=3d32cbf813bc2615b211888748018fbebb77b5d8;hp=23dff2038f3ef17b1090ba63e186771f9ee5d60a;hb=54185c70692f8a6d9c667214743e0ffd07a0afa3;hpb=ebbcac93ae32a4264d3355c2202034e78db703a0

diff --git a/src/bin/lttng/commands/enable_events.c b/src/bin/lttng/commands/enable_events.c
index 23dff2038..3d32cbf81 100644
--- a/src/bin/lttng/commands/enable_events.c
+++ b/src/bin/lttng/commands/enable_events.c
@@ -290,6 +290,65 @@ end:
 	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
@@ -389,7 +448,7 @@ static int parse_userspace_probe_opts(struct lttng_event *ev, char *opt)
 	/* strutils_unescape_string allocates a new char *. */
 	unescaped_target_path = strutils_unescape_string(target_path, 0);
 	if (!unescaped_target_path) {
-		ret = -LTTNG_ERR_INVALID;
+		ret = CMD_ERROR;
 		goto end_destroy_lookup_method;
 	}
 
@@ -425,11 +484,12 @@ static int parse_userspace_probe_opts(struct lttng_event *ev, char *opt)
 		}
 
 		/*
-		 * Check if the file exists using access(2). If it does not, walk the
-		 * $PATH.
+		 * Check if the file exists using access(2), If it does not,
+		 * return an error.
 		 */
 		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;
 		}
@@ -437,6 +497,14 @@ static int parse_userspace_probe_opts(struct lttng_event *ev, char *opt)
 
 	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) {
@@ -737,7 +805,7 @@ char *print_exclusions(char **names)
 {
 	int length = 0;
 	int i;
-	const char *preamble = " excluding ";
+	const char preamble[] = " excluding ";
 	char *ret;
 	int count = names ? strutils_array_of_strings_len(names) : 0;
 
@@ -750,9 +818,8 @@ char *print_exclusions(char **names)
 		length += strlen(names[i]) + 4;
 	}
 
-	/* add length of preamble + one for NUL - one for last (missing) comma */
-	length += strlen(preamble);
-	ret = zmalloc(length + 1);
+	length += sizeof(preamble);
+	ret = zmalloc(length);
 	if (!ret) {
 		return NULL;
 	}
@@ -1296,8 +1363,19 @@ static int enable_events(char *session_name)
 			case LTTNG_EVENT_USERSPACE_PROBE:
 				ret = parse_userspace_probe_opts(ev, opt_userspace_probe);
 				if (ret) {
-					ERR("Unable to parse userspace probe options");
-					ret = CMD_ERROR;
+					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;