X-Git-Url: https://git.lttng.org/?p=lttng-tools.git;a=blobdiff_plain;f=src%2Fbin%2Flttng%2Fuprobe.c;fp=src%2Fbin%2Flttng%2Fuprobe.c;h=0000000000000000000000000000000000000000;hp=2a2890184d766c2279b36fccfcc7372f20472fd0;hb=48a4000561343808724f7cb5fa8c131877489ccd;hpb=81663f073dbfb4b61c06a0ceb8ca33c4fc41b1c5 diff --git a/src/bin/lttng/uprobe.c b/src/bin/lttng/uprobe.c deleted file mode 100644 index 2a2890184..000000000 --- a/src/bin/lttng/uprobe.c +++ /dev/null @@ -1,388 +0,0 @@ -/* - * Copyright (C) 2020 EfficiOS, Inc. - * - * SPDX-License-Identifier: GPL-2.0-only - * - */ - -#include "uprobe.h" - -#include -#include -#include - -#include "common/compat/getenv.h" -#include "common/string-utils/string-utils.h" -#include "common/utils.h" -#include "lttng/constant.h" - -#include "command.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 = zmalloc(LTTNG_PATH_MAX * sizeof(char)); - 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(lttng_dynamic_pointer_array_get_pointer(&tokens, 0), "elf") == 0) { - target_path = lttng_dynamic_pointer_array_get_pointer(&tokens, 1); - symbol_name = lttng_dynamic_pointer_array_get_pointer(&tokens, 2); - } else if (num_token == 2) { - target_path = lttng_dynamic_pointer_array_get_pointer(&tokens, 0); - symbol_name = 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(lttng_dynamic_pointer_array_get_pointer(&tokens, 0), "sdt") == 0) { - target_path = lttng_dynamic_pointer_array_get_pointer(&tokens, 1); - provider_name = lttng_dynamic_pointer_array_get_pointer(&tokens, 2); - probe_name = 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 = zmalloc(LTTNG_PATH_MAX * sizeof(char)); - 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; -}