[lttng-tools.git] / src / bin / lttng / uprobe.cpp

/*
 * Copyright (C) 2020 EfficiOS, Inc.
 *
 * SPDX-License-Identifier: GPL-2.0-only
 *
 */

#include "command.hpp"
#include "common/compat/getenv.hpp"
#include "common/path.hpp"
#include "common/string-utils/string-utils.hpp"
#include "common/utils.hpp"
#include "lttng/constant.h"
#include "uprobe.hpp"

#include <sys/stat.h>
#include <sys/types.h>
#include <unistd.h>

/*
 * Walk the directories in the PATH environment variable to find the target
 * binary passed as parameter.
 *
 * On success, the full path of the binary is copied in binary_full_path out
 * parameter. This buffer is allocated by the caller and must be at least
 * LTTNG_PATH_MAX bytes long.
 * On failure, returns -1;
 */
static int walk_command_search_path(const char *binary, char *binary_full_path)
{
	char *tentative_binary_path = NULL;
	char *command_search_path = NULL;
	char *curr_search_dir_end = NULL;
	char *curr_search_dir = NULL;
	struct stat stat_output;
	int ret = 0;

	command_search_path = lttng_secure_getenv("PATH");
	if (!command_search_path) {
		ret = -1;
		goto end;
	}

	/*
	 * Duplicate the $PATH string as the char pointer returned by getenv() should
	 * not be modified.
	 */
	command_search_path = strdup(command_search_path);
	if (!command_search_path) {
		ret = -1;
		goto end;
	}

	/*
	 * This char array is used to concatenate path to binary to look for
	 * the binary.
	 */
	tentative_binary_path = calloc<char>(LTTNG_PATH_MAX);
	if (!tentative_binary_path) {
		ret = -1;
		goto alloc_error;
	}

	curr_search_dir = command_search_path;
	do {
		/*
		 * Split on ':'. The return value of this call points to the
		 * matching character.
		 */
		curr_search_dir_end = strchr(curr_search_dir, ':');
		if (curr_search_dir_end != NULL) {
			/*
			 * Add a NULL byte to the end of the first token so it
			 * can be used as a string.
			 */
			curr_search_dir_end[0] = '\0';
		}

		/* Empty the tentative path */
		memset(tentative_binary_path, 0, LTTNG_PATH_MAX * sizeof(char));

		/*
		 * Build the tentative path to the binary using the current
		 * search directory and the name of the binary.
		 */
		ret = snprintf(
			tentative_binary_path, LTTNG_PATH_MAX, "%s/%s", curr_search_dir, binary);
		if (ret < 0) {
			goto free_binary_path;
		}
		if (ret < LTTNG_PATH_MAX) {
			/*
			 * Use STAT(2) to see if the file exists.
			 */
			ret = stat(tentative_binary_path, &stat_output);
			if (ret == 0) {
				/*
				 * Verify that it is a regular file or a
				 * symlink and not a special file (e.g.
				 * device).
				 */
				if (S_ISREG(stat_output.st_mode) || S_ISLNK(stat_output.st_mode)) {
					/*
					 * Found a match, set the out parameter
					 * and return success.
					 */
					ret = lttng_strncpy(binary_full_path,
							    tentative_binary_path,
							    LTTNG_PATH_MAX);
					if (ret == -1) {
						ERR("Source path does not fit "
						    "in destination buffer.");
					}
					goto free_binary_path;
				}
			}
		}
		/* Go to the next entry in the $PATH variable. */
		curr_search_dir = curr_search_dir_end + 1;
	} while (curr_search_dir_end != NULL);

free_binary_path:
	free(tentative_binary_path);
alloc_error:
	free(command_search_path);
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
 * target_path to the path to the binary.
 */
int parse_userspace_probe_opts(const char *opt,
			       struct lttng_userspace_probe_location **probe_location)
{
	int ret = CMD_SUCCESS;
	size_t num_token = 0;
	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_local = NULL;
	struct lttng_userspace_probe_location_lookup_method *lookup_method = NULL;
	struct lttng_dynamic_pointer_array tokens;

	LTTNG_ASSERT(opt);

	/*
	 * userspace probe fields are separated by ':'.
	 */
	ret = strutils_split(opt, ':', true, &tokens);
	if (ret == 0) {
		num_token = lttng_dynamic_pointer_array_get_count(&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 (ret < 0 || num_token < 2 || num_token > 4) {
		ret = CMD_ERROR;
		goto end;
	}

	/*
	 * 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((const char *) lttng_dynamic_pointer_array_get_pointer(&tokens, 0),
			   "elf") == 0) {
			target_path = (char *) lttng_dynamic_pointer_array_get_pointer(&tokens, 1);
			symbol_name = (char *) lttng_dynamic_pointer_array_get_pointer(&tokens, 2);
		} else if (num_token == 2) {
			target_path = (char *) lttng_dynamic_pointer_array_get_pointer(&tokens, 0);
			symbol_name = (char *) lttng_dynamic_pointer_array_get_pointer(&tokens, 1);
		} else {
			ret = CMD_ERROR;
			goto end;
		}
		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;
		}
		break;
	case 4:
		if (strcmp((const char *) lttng_dynamic_pointer_array_get_pointer(&tokens, 0),
			   "sdt") == 0) {
			target_path = (char *) lttng_dynamic_pointer_array_get_pointer(&tokens, 1);
			provider_name =
				(char *) lttng_dynamic_pointer_array_get_pointer(&tokens, 2);
			probe_name = (char *) lttng_dynamic_pointer_array_get_pointer(&tokens, 3);
		} else {
			ret = CMD_ERROR;
			goto end;
		}
		lookup_method =
			lttng_userspace_probe_location_lookup_method_tracepoint_sdt_create();
		if (!lookup_method) {
			WARN("Failed to create SDT lookup method");
			ret = CMD_ERROR;
			goto end;
		}
		break;
	default:
		ret = CMD_ERROR;
		goto end;
	}

	/* 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;
	}

	/*
	 * 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 = calloc<char>(LTTNG_PATH_MAX);
		if (!real_target_path) {
			PERROR("Error allocating path buffer");
			ret = CMD_ERROR;
			goto end;
		}
		ret = walk_command_search_path(unescaped_target_path, real_target_path);
		if (ret) {
			ERR("Binary not found.");
			ret = CMD_ERROR;
			goto end;
		}
	} 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;
		}

		/*
		 * 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;
		}
	}

	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;
		}

		probe_location_local = lttng_userspace_probe_location_function_create(
			real_target_path, symbol_name, lookup_method);
		if (!probe_location_local) {
			WARN("Failed to create function probe location");
			ret = CMD_ERROR;
			goto end;
		}

		/* Ownership transferred to probe_location. */
		lookup_method = NULL;
		break;
	case LTTNG_USERSPACE_PROBE_LOCATION_LOOKUP_METHOD_TYPE_TRACEPOINT_SDT:
		probe_location_local = lttng_userspace_probe_location_tracepoint_create(
			real_target_path, provider_name, probe_name, lookup_method);
		if (!probe_location_local) {
			WARN("Failed to create function probe location");
			ret = CMD_ERROR;
			goto end;
		}

		/* Ownership transferred to probe_location. */
		lookup_method = NULL;
		break;
	default:
		ret = CMD_ERROR;
		goto end;
	}

	/*
	 * Everything went fine, transfer ownership of probe location to
	 * caller.
	 */
	*probe_location = probe_location_local;
	probe_location_local = NULL;

end:
	lttng_userspace_probe_location_destroy(probe_location_local);
	lttng_userspace_probe_location_lookup_method_destroy(lookup_method);
	lttng_dynamic_pointer_array_reset(&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);

	return ret;
}
Commit	Line	Data
0c4e727b JR	1	/*
	2	* Copyright (C) 2020 EfficiOS, Inc.
	3	*
	4	* SPDX-License-Identifier: GPL-2.0-only
	5	*
	6	*/
	7
28ab034a	8	#include "command.hpp"
c9e313bc	9	#include "common/compat/getenv.hpp"
28ab034a	10	#include "common/path.hpp"
c9e313bc SM	11	#include "common/string-utils/string-utils.hpp"
c9e313bc SM	12	#include "common/utils.hpp"
0c4e727b	13	#include "lttng/constant.h"
28ab034a	14	#include "uprobe.hpp"
0c4e727b	15
28ab034a JG	16	#include <sys/stat.h>
	17	#include <sys/types.h>
	18	#include <unistd.h>
0c4e727b JR	19
	20	/*
	21	* Walk the directories in the PATH environment variable to find the target
	22	* binary passed as parameter.
	23	*
	24	* On success, the full path of the binary is copied in binary_full_path out
	25	* parameter. This buffer is allocated by the caller and must be at least
	26	* LTTNG_PATH_MAX bytes long.
	27	* On failure, returns -1;
	28	*/
28ab034a	29	static int walk_command_search_path(const char binary, char binary_full_path)
0c4e727b JR	30	{
	31	char *tentative_binary_path = NULL;
	32	char *command_search_path = NULL;
	33	char *curr_search_dir_end = NULL;
	34	char *curr_search_dir = NULL;
	35	struct stat stat_output;
	36	int ret = 0;
	37
	38	command_search_path = lttng_secure_getenv("PATH");
	39	if (!command_search_path) {
	40	ret = -1;
	41	goto end;
	42	}
	43
	44	/*
	45	* Duplicate the $PATH string as the char pointer returned by getenv() should
	46	* not be modified.
	47	*/
	48	command_search_path = strdup(command_search_path);
	49	if (!command_search_path) {
	50	ret = -1;
	51	goto end;
	52	}
	53
	54	/*
	55	* This char array is used to concatenate path to binary to look for
	56	* the binary.
	57	*/
64803277	58	tentative_binary_path = calloc<char>(LTTNG_PATH_MAX);
0c4e727b JR	59	if (!tentative_binary_path) {
	60	ret = -1;
	61	goto alloc_error;
	62	}
	63
	64	curr_search_dir = command_search_path;
	65	do {
	66	/*
	67	* Split on ':'. The return value of this call points to the
	68	* matching character.
	69	*/
	70	curr_search_dir_end = strchr(curr_search_dir, ':');
	71	if (curr_search_dir_end != NULL) {
	72	/*
	73	* Add a NULL byte to the end of the first token so it
	74	* can be used as a string.
	75	*/
	76	curr_search_dir_end[0] = '\0';
	77	}
	78
	79	/* Empty the tentative path */
	80	memset(tentative_binary_path, 0, LTTNG_PATH_MAX * sizeof(char));
	81
	82	/*
	83	* Build the tentative path to the binary using the current
	84	* search directory and the name of the binary.
	85	*/
28ab034a JG	86	ret = snprintf(
28ab034a JG	87	tentative_binary_path, LTTNG_PATH_MAX, "%s/%s", curr_search_dir, binary);
0c4e727b JR	88	if (ret < 0) {
	89	goto free_binary_path;
	90	}
	91	if (ret < LTTNG_PATH_MAX) {
28ab034a JG	92	/*
28ab034a JG	93	* Use STAT(2) to see if the file exists.
0c4e727b JR	94	*/
	95	ret = stat(tentative_binary_path, &stat_output);
	96	if (ret == 0) {
	97	/*
	98	* Verify that it is a regular file or a
	99	* symlink and not a special file (e.g.
	100	* device).
	101	*/
28ab034a	102	if (S_ISREG(stat_output.st_mode) \|\| S_ISLNK(stat_output.st_mode)) {
0c4e727b JR	103	/*
	104	* Found a match, set the out parameter
	105	* and return success.
	106	*/
	107	ret = lttng_strncpy(binary_full_path,
28ab034a JG	108	tentative_binary_path,
28ab034a JG	109	LTTNG_PATH_MAX);
0c4e727b JR	110	if (ret == -1) {
0c4e727b JR	111	ERR("Source path does not fit "
28ab034a	112	"in destination buffer.");
0c4e727b JR	113	}
	114	goto free_binary_path;
	115	}
	116	}
	117	}
	118	/* Go to the next entry in the $PATH variable. */
	119	curr_search_dir = curr_search_dir_end + 1;
	120	} while (curr_search_dir_end != NULL);
	121
	122	free_binary_path:
	123	free(tentative_binary_path);
	124	alloc_error:
	125	free(command_search_path);
	126	end:
	127	return ret;
	128	}
	129
	130	/*
	131	* Check if the symbol field passed by the user is in fact an address or an
	132	* offset from a symbol. Those two instrumentation types are not supported yet.
	133	* It's expected to be a common mistake because of the existing --probe option
	134	* that does support these formats.
	135	*
	136	* Here are examples of these unsupported formats for the --userspace-probe
	137	* option:
	138	* elf:/path/to/binary:0x400430
	139	* elf:/path/to/binary:4194364
	140	* elf:/path/to/binary:my_symbol+0x323
	141	* elf:/path/to/binary:my_symbol+43
	142	*/
28ab034a	143	static int warn_userspace_probe_syntax(const char *symbol)
0c4e727b JR	144	{
	145	int ret;
	146
	147	/* Check if the symbol field is an hex address. */
	148	ret = sscanf(symbol, "0x%*x");
	149	if (ret > 0) {
	150	/* If there is a match, print a warning and return an error. */
	151	ERR("Userspace probe on address not supported yet.");
	152	ret = CMD_UNSUPPORTED;
	153	goto error;
	154	}
	155
	156	/* Check if the symbol field is an decimal address. */
	157	ret = sscanf(symbol, "%*u");
	158	if (ret > 0) {
	159	/* If there is a match, print a warning and return an error. */
	160	ERR("Userspace probe on address not supported yet.");
	161	ret = CMD_UNSUPPORTED;
	162	goto error;
	163	}
	164
	165	/* Check if the symbol field is symbol+hex_offset. */
	166	ret = sscanf(symbol, "%[^+]+0x%x");
	167	if (ret > 0) {
	168	/* If there is a match, print a warning and return an error. */
	169	ERR("Userspace probe on symbol+offset not supported yet.");
	170	ret = CMD_UNSUPPORTED;
	171	goto error;
	172	}
	173
	174	/* Check if the symbol field is symbol+decimal_offset. */
	175	ret = sscanf(symbol, "%[^+]+%u");
	176	if (ret > 0) {
	177	/* If there is a match, print a warning and return an error. */
	178	ERR("Userspace probe on symbol+offset not supported yet.");
	179	ret = CMD_UNSUPPORTED;
	180	goto error;
	181	}
	182
	183	ret = 0;
	184
	185	error:
	186	return ret;
	187	}
	188
	189	/*
	190	* Parse userspace probe options
	191	* Set the userspace probe fields in the lttng_event struct and set the
	192	* target_path to the path to the binary.
	193	*/
0c4e727b	194	int parse_userspace_probe_opts(const char *opt,
28ab034a	195	struct lttng_userspace_probe_location **probe_location)
0c4e727b JR	196	{
0c4e727b JR	197	int ret = CMD_SUCCESS;
e358ddd5	198	size_t num_token = 0;
0c4e727b JR	199	char *target_path = NULL;
	200	char *unescaped_target_path = NULL;
	201	char *real_target_path = NULL;
	202	char symbol_name = NULL, probe_name = NULL, *provider_name = NULL;
	203	struct lttng_userspace_probe_location *probe_location_local = NULL;
	204	struct lttng_userspace_probe_location_lookup_method *lookup_method = NULL;
e358ddd5	205	struct lttng_dynamic_pointer_array tokens;
0c4e727b	206
a0377dfe	207	LTTNG_ASSERT(opt);
0c4e727b JR	208
	209	/*
	210	* userspace probe fields are separated by ':'.
	211	*/
e358ddd5 JG	212	ret = strutils_split(opt, ':', true, &tokens);
	213	if (ret == 0) {
	214	num_token = lttng_dynamic_pointer_array_get_count(&tokens);
	215	}
0c4e727b JR	216
	217	/*
	218	* Early sanity check that the number of parameter is between 2 and 4
	219	* inclusively.
	220	* elf:PATH:SYMBOL
	221	* std:PATH:PROVIDER_NAME:PROBE_NAME
	222	* PATH:SYMBOL (same behavior as ELF)
	223	*/
e358ddd5	224	if (ret < 0 \|\| num_token < 2 \|\| num_token > 4) {
0c4e727b JR	225	ret = CMD_ERROR;
	226	goto end;
	227	}
	228
	229	/*
	230	* Looking up the first parameter will tell the technique to use to
	231	* interpret the userspace probe/function description.
	232	*/
	233	switch (num_token) {
	234	case 2:
	235	/* When the probe type is omitted we assume ELF for now. */
	236	case 3:
28ab034a JG	237	if (num_token == 3 &&
	238	strcmp((const char *) lttng_dynamic_pointer_array_get_pointer(&tokens, 0),
	239	"elf") == 0) {
48a40005 SM	240	target_path = (char *) lttng_dynamic_pointer_array_get_pointer(&tokens, 1);
48a40005 SM	241	symbol_name = (char *) lttng_dynamic_pointer_array_get_pointer(&tokens, 2);
0c4e727b	242	} else if (num_token == 2) {
48a40005 SM	243	target_path = (char *) lttng_dynamic_pointer_array_get_pointer(&tokens, 0);
48a40005 SM	244	symbol_name = (char *) lttng_dynamic_pointer_array_get_pointer(&tokens, 1);
0c4e727b JR	245	} else {
	246	ret = CMD_ERROR;
	247	goto end;
	248	}
28ab034a	249	lookup_method = lttng_userspace_probe_location_lookup_method_function_elf_create();
0c4e727b JR	250	if (!lookup_method) {
	251	WARN("Failed to create ELF lookup method");
	252	ret = CMD_ERROR;
	253	goto end;
	254	}
	255	break;
	256	case 4:
28ab034a JG	257	if (strcmp((const char *) lttng_dynamic_pointer_array_get_pointer(&tokens, 0),
28ab034a JG	258	"sdt") == 0) {
48a40005	259	target_path = (char *) lttng_dynamic_pointer_array_get_pointer(&tokens, 1);
28ab034a JG	260	provider_name =
28ab034a JG	261	(char *) lttng_dynamic_pointer_array_get_pointer(&tokens, 2);
48a40005	262	probe_name = (char *) lttng_dynamic_pointer_array_get_pointer(&tokens, 3);
0c4e727b JR	263	} else {
	264	ret = CMD_ERROR;
	265	goto end;
	266	}
	267	lookup_method =
	268	lttng_userspace_probe_location_lookup_method_tracepoint_sdt_create();
	269	if (!lookup_method) {
	270	WARN("Failed to create SDT lookup method");
	271	ret = CMD_ERROR;
	272	goto end;
	273	}
	274	break;
	275	default:
	276	ret = CMD_ERROR;
	277	goto end;
	278	}
	279
	280	/* strutils_unescape_string allocates a new char . /
	281	unescaped_target_path = strutils_unescape_string(target_path, 0);
	282	if (!unescaped_target_path) {
	283	ret = CMD_ERROR;
	284	goto end;
	285	}
	286
	287	/*
	288	* If there is not forward slash in the path. Walk the $PATH else
	289	* expand.
	290	*/
	291	if (strchr(unescaped_target_path, '/') == NULL) {
	292	/* Walk the $PATH variable to find the targeted binary. */
64803277	293	real_target_path = calloc<char>(LTTNG_PATH_MAX);
0c4e727b JR	294	if (!real_target_path) {
	295	PERROR("Error allocating path buffer");
	296	ret = CMD_ERROR;
	297	goto end;
	298	}
	299	ret = walk_command_search_path(unescaped_target_path, real_target_path);
	300	if (ret) {
	301	ERR("Binary not found.");
	302	ret = CMD_ERROR;
	303	goto end;
	304	}
	305	} else {
	306	/*
	307	* Expand references to `/./` and `/../`. This function does not check
	308	* if the file exists. This call returns an allocated buffer on
	309	* success.
	310	*/
	311	real_target_path = utils_expand_path_keep_symlink(unescaped_target_path);
	312	if (!real_target_path) {
	313	ERR("Error expanding the path to binary.");
	314	ret = CMD_ERROR;
	315	goto end;
	316	}
	317
	318	/*
	319	* Check if the file exists using access(2), If it does not,
	320	* return an error.
	321	*/
	322	ret = access(real_target_path, F_OK);
	323	if (ret) {
	324	ERR("Cannot find binary at path: %s.", real_target_path);
	325	ret = CMD_ERROR;
	326	goto end;
	327	}
	328	}
	329
	330	switch (lttng_userspace_probe_location_lookup_method_get_type(lookup_method)) {
	331	case LTTNG_USERSPACE_PROBE_LOCATION_LOOKUP_METHOD_TYPE_FUNCTION_ELF:
	332	/*
	333	* Check for common mistakes in userspace probe description syntax.
	334	*/
	335	ret = warn_userspace_probe_syntax(symbol_name);
	336	if (ret) {
	337	goto end;
	338	}
	339
	340	probe_location_local = lttng_userspace_probe_location_function_create(
28ab034a	341	real_target_path, symbol_name, lookup_method);
0c4e727b JR	342	if (!probe_location_local) {
	343	WARN("Failed to create function probe location");
	344	ret = CMD_ERROR;
	345	goto end;
	346	}
	347
	348	/* Ownership transferred to probe_location. */
	349	lookup_method = NULL;
	350	break;
	351	case LTTNG_USERSPACE_PROBE_LOCATION_LOOKUP_METHOD_TYPE_TRACEPOINT_SDT:
	352	probe_location_local = lttng_userspace_probe_location_tracepoint_create(
28ab034a	353	real_target_path, provider_name, probe_name, lookup_method);
0c4e727b JR	354	if (!probe_location_local) {
	355	WARN("Failed to create function probe location");
	356	ret = CMD_ERROR;
	357	goto end;
	358	}
	359
	360	/* Ownership transferred to probe_location. */
	361	lookup_method = NULL;
	362	break;
	363	default:
	364	ret = CMD_ERROR;
	365	goto end;
	366	}
	367
	368	/*
	369	* Everything went fine, transfer ownership of probe location to
	370	* caller.
	371	*/
	372	*probe_location = probe_location_local;
	373	probe_location_local = NULL;
	374
	375	end:
	376	lttng_userspace_probe_location_destroy(probe_location_local);
	377	lttng_userspace_probe_location_lookup_method_destroy(lookup_method);
e358ddd5	378	lttng_dynamic_pointer_array_reset(&tokens);
0c4e727b JR	379	/*
	380	* Freeing both char * here makes the error handling simplier. free()
	381	* performs not action if the pointer is NULL.
	382	*/
	383	free(real_target_path);
	384	free(unescaped_target_path);
	385
	386	return ret;
	387	}