X-Git-Url: http://git.efficios.com/?p=babeltrace.git;a=blobdiff_plain;f=lib%2Fbin-info.c;fp=lib%2Fbin-info.c;h=023515effd510f1d118bab45f3e1f32382c279aa;hp=0000000000000000000000000000000000000000;hb=d5ddf820bf2640c74a0581d408b48e9edf8b1984;hpb=6764ed54802782af3565686fc28ae1e17b9fa75a diff --git a/lib/bin-info.c b/lib/bin-info.c new file mode 100644 index 00000000..023515ef --- /dev/null +++ b/lib/bin-info.c @@ -0,0 +1,1325 @@ +/* + * bin-info.c + * + * Babeltrace - Executable and Shared Object Debug Info Reader + * + * Copyright 2015 Antoine Busque + * + * Author: Antoine Busque + * + * Permission is hereby granted, free of charge, to any person obtaining a copy + * of this software and associated documentation files (the "Software"), to deal + * in the Software without restriction, including without limitation the rights + * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell + * copies of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be included in + * all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE + * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE + * SOFTWARE. + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +/* + * An address printed in hex is at most 20 bytes (16 for 64-bits + + * leading 0x + optional leading '+' if addr is an offset + null + * character). + */ +#define ADDR_STR_LEN 20 + +BT_HIDDEN +int bin_info_init(void) +{ + int ret = 0; + + if (elf_version(EV_CURRENT) == EV_NONE) { + printf_debug("ELF library initialization failed: %s\n", + elf_errmsg(-1)); + ret = -1; + } + + return ret; +} + +BT_HIDDEN +struct bin_info *bin_info_create(const char *path, uint64_t low_addr, + uint64_t memsz, bool is_pic) +{ + struct bin_info *bin = NULL; + + if (!path) { + goto error; + } + + bin = g_new0(struct bin_info, 1); + if (!bin) { + goto error; + } + + if (opt_debug_info_target_prefix) { + bin->elf_path = g_build_path("/", opt_debug_info_target_prefix, + path, NULL); + } else { + bin->elf_path = strdup(path); + } + + if (!bin->elf_path) { + goto error; + } + + bin->is_pic = is_pic; + bin->memsz = memsz; + bin->low_addr = low_addr; + bin->high_addr = bin->low_addr + bin->memsz; + + return bin; + +error: + bin_info_destroy(bin); + return NULL; +} + +BT_HIDDEN +void bin_info_destroy(struct bin_info *bin) +{ + if (!bin) { + return; + } + + dwarf_end(bin->dwarf_info); + + free(bin->elf_path); + free(bin->dwarf_path); + free(bin->build_id); + free(bin->dbg_link_filename); + + elf_end(bin->elf_file); + + close(bin->elf_fd); + close(bin->dwarf_fd); + + g_free(bin); +} + + +BT_HIDDEN +int bin_info_set_build_id(struct bin_info *bin, uint8_t *build_id, + size_t build_id_len) +{ + if (!bin || !build_id) { + goto error; + } + + bin->build_id = malloc(build_id_len); + if (!bin->build_id) { + goto error; + } + + memcpy(bin->build_id, build_id, build_id_len); + bin->build_id_len = build_id_len; + + /* + * Reset the is_elf_only flag in case it had been set + * previously, because we might find separate debug info using + * the new build id information. + */ + bin->is_elf_only = false; + + return 0; + +error: + + return -1; +} + +BT_HIDDEN +int bin_info_set_debug_link(struct bin_info *bin, char *filename, uint32_t crc) +{ + if (!bin || !filename) { + goto error; + } + + bin->dbg_link_filename = strdup(filename); + if (!bin->dbg_link_filename) { + goto error; + } + + bin->dbg_link_crc = crc; + + /* + * Reset the is_elf_only flag in case it had been set + * previously, because we might find separate debug info using + * the new build id information. + */ + bin->is_elf_only = false; + + return 0; + +error: + + return -1; +} + +/** + * Tries to read DWARF info from the location given by path, and + * attach it to the given bin_info instance if it exists. + * + * @param bin bin_info instance for which to set DWARF info + * @param path Presumed location of the DWARF info + * @returns 0 on success, -1 on failure + */ +static +int bin_info_set_dwarf_info_from_path(struct bin_info *bin, char *path) +{ + int fd = -1, ret = 0; + struct bt_dwarf_cu *cu = NULL; + Dwarf *dwarf_info = NULL; + + if (!bin || !path) { + goto error; + } + + fd = open(path, O_RDONLY); + if (fd < 0) { + goto error; + } + + dwarf_info = dwarf_begin(fd, DWARF_C_READ); + if (!dwarf_info) { + goto error; + } + + /* + * Check if the dwarf info has any CU. If not, the + * executable's object file contains no DWARF info. + */ + cu = bt_dwarf_cu_create(dwarf_info); + if (!cu) { + goto error; + } + + ret = bt_dwarf_cu_next(cu); + if (ret) { + goto error; + } + + bin->dwarf_fd = fd; + bin->dwarf_path = strdup(path); + if (!bin->dwarf_path) { + goto error; + } + bin->dwarf_info = dwarf_info; + free(cu); + + return 0; + +error: + close(fd); + dwarf_end(dwarf_info); + g_free(dwarf_info); + free(cu); + + return -1; +} + +/** + * Try to set the dwarf_info for a given bin_info instance via the + * build ID method. + * + * @param bin bin_info instance for which to retrieve the + * DWARF info via build ID + * @returns 0 on success (i.e. dwarf_info set), -1 on failure + */ +static +int bin_info_set_dwarf_info_build_id(struct bin_info *bin) +{ + int i = 0, ret = 0; + char *path = NULL, *build_id_file = NULL; + const char *dbg_dir = NULL; + size_t build_id_file_len; + + if (!bin || !bin->build_id) { + goto error; + } + + dbg_dir = opt_debug_info_dir ? : DEFAULT_DEBUG_DIR; + + /* 2 characters per byte printed in hex, +1 for '/' and +1 for + * '\0' */ + build_id_file_len = (2 * bin->build_id_len) + 1 + + strlen(BUILD_ID_SUFFIX) + 1; + build_id_file = malloc(build_id_file_len); + if (!build_id_file) { + goto error; + } + + snprintf(build_id_file, 4, "%02x/", bin->build_id[0]); + for (i = 1; i < bin->build_id_len; ++i) { + int path_idx = 3 + 2 * (i - 1); + + snprintf(&build_id_file[path_idx], 3, "%02x", bin->build_id[i]); + } + strcat(build_id_file, BUILD_ID_SUFFIX); + + path = g_build_path("/", dbg_dir, BUILD_ID_SUBDIR, build_id_file, NULL); + if (!path) { + goto error; + } + + ret = bin_info_set_dwarf_info_from_path(bin, path); + if (ret) { + goto error; + } + + goto end; + +error: + ret = -1; +end: + free(build_id_file); + free(path); + + return ret; +} + +/** + * Tests whether the file located at path exists and has the expected + * checksum. + * + * This predicate is used when looking up separate debug info via the + * GNU debuglink method. The expected crc can be found .gnu_debuglink + * section in the original ELF file, along with the filename for the + * file containing the debug info. + * + * @param path Full path at which to look for the debug file + * @param crc Expected checksum for the debug file + * @returns 1 if the file exists and has the correct checksum, + * 0 otherwise + */ +static +int is_valid_debug_file(char *path, uint32_t crc) +{ + int ret = 0, fd = -1; + uint32_t _crc = 0; + + if (!path) { + goto end; + } + + fd = open(path, O_RDONLY); + if (fd < 0) { + goto end; + } + + ret = crc32(fd, &_crc); + if (ret) { + ret = 0; + goto end; + } + + ret = (crc == _crc); + +end: + close(fd); + return ret; +} + +/** + * Try to set the dwarf_info for a given bin_info instance via the + * build ID method. + * + * @param bin bin_info instance for which to retrieve the + * DWARF info via debug link + * @returns 0 on success (i.e. dwarf_info set), -1 on failure + */ +static +int bin_info_set_dwarf_info_debug_link(struct bin_info *bin) +{ + int ret = 0; + const char *dbg_dir = NULL; + char *dir_name = NULL, *bin_dir = NULL, *path = NULL; + size_t max_path_len = 0; + + if (!bin || !bin->dbg_link_filename) { + goto error; + } + + dbg_dir = opt_debug_info_dir ? : DEFAULT_DEBUG_DIR; + + dir_name = dirname(bin->elf_path); + if (!dir_name) { + goto error; + } + + /* bin_dir is just dir_name with a trailing slash */ + bin_dir = malloc(strlen(dir_name) + 2); + if (!bin_dir) { + goto error; + } + + strcpy(bin_dir, dir_name); + strcat(bin_dir, "/"); + + max_path_len = strlen(dbg_dir) + strlen(bin_dir) + + strlen(DEBUG_SUBDIR) + strlen(bin->dbg_link_filename) + + 1; + path = malloc(max_path_len); + if (!path) { + goto error; + } + + /* First look in the executable's dir */ + strcpy(path, bin_dir); + strcat(path, bin->dbg_link_filename); + + if (is_valid_debug_file(path, bin->dbg_link_crc)) { + goto found; + } + + /* If not found, look in .debug subdir */ + strcpy(path, bin_dir); + strcat(path, DEBUG_SUBDIR); + strcat(path, bin->dbg_link_filename); + + if (is_valid_debug_file(path, bin->dbg_link_crc)) { + goto found; + } + + /* Lastly, look under the global debug directory */ + strcpy(path, dbg_dir); + strcat(path, bin_dir); + strcat(path, bin->dbg_link_filename); + + if (is_valid_debug_file(path, bin->dbg_link_crc)) { + goto found; + } + +error: + ret = -1; +end: + free(path); + free(bin_dir); + + return ret; + +found: + ret = bin_info_set_dwarf_info_from_path(bin, path); + if (ret) { + goto error; + } + + goto end; +} + +/** + * Initialize the DWARF info for a given executable. + * + * @param bin bin_info instance + * @returns 0 on success, -1 on failure + */ +static +int bin_info_set_dwarf_info(struct bin_info *bin) +{ + int ret = 0; + + if (!bin) { + goto error; + } + + /* First try to set the DWARF info from the ELF file */ + ret = bin_info_set_dwarf_info_from_path(bin, bin->elf_path); + if (!ret) { + goto end; + } + + /* + * If that fails, try to find separate debug info via build ID + * and debug link. + */ + ret = bin_info_set_dwarf_info_build_id(bin); + if (!ret) { + goto end; + } + + ret = bin_info_set_dwarf_info_debug_link(bin); + if (!ret) { + goto end; + } + +error: + ret = -1; +end: + return ret; +} + +/** + * Initialize the ELF file for a given executable. + * + * @param bin bin_info instance + * @returns 0 on success, -1 on failure + */ +static +int bin_info_set_elf_file(struct bin_info *bin) +{ + int elf_fd; + Elf *elf_file = NULL; + + if (!bin) { + goto error; + } + + elf_fd = open(bin->elf_path, O_RDONLY); + if (elf_fd < 0) { + printf_verbose("Failed to open %s\n", bin->elf_path); + goto error; + } + + elf_file = elf_begin(elf_fd, ELF_C_READ, NULL); + if (!elf_file) { + printf_debug("elf_begin failed: %s\n", elf_errmsg(-1)); + goto error; + } + + if (elf_kind(elf_file) != ELF_K_ELF) { + printf_verbose("Error: %s is not an ELF object\n", + bin->elf_path); + goto error; + } + + bin->elf_fd = elf_fd; + bin->elf_file = elf_file; + return 0; + +error: + close(elf_fd); + elf_end(elf_file); + return -1; +} + + +BT_HIDDEN +void source_location_destroy(struct source_location *src_loc) +{ + if (!src_loc) { + return; + } + + free(src_loc->filename); + g_free(src_loc); +} +/** + * Append a string representation of an address offset to an existing + * string. + * + * On success, the out parameter `result` will contain the base string + * followed by the offset string of the form "+0x1234". On failure, + * `result` remains unchanged. + * + * @param base_str The string to which to append an offset string + * @param low_addr The lower virtual memory address, the base from + * which the offset is computed + * @param high_addr The higher virtual memory address + * @param result Out parameter, the base string followed by the + * offset string + * @returns 0 on success, -1 on failure + */ +static +int bin_info_append_offset_str(const char *base_str, uint64_t low_addr, + uint64_t high_addr, char **result) +{ + int ret; + uint64_t offset; + char *_result = NULL; + char offset_str[ADDR_STR_LEN]; + + if (!base_str || !result) { + goto error; + } + + offset = high_addr - low_addr; + + _result = malloc(strlen(base_str) + ADDR_STR_LEN); + if (!_result) { + goto error; + } + + ret = snprintf(offset_str, ADDR_STR_LEN, "+%#0" PRIx64, offset); + if (ret < 0) { + goto error; + } + strcpy(_result, base_str); + strcat(_result, offset_str); + *result = _result; + + return 0; + +error: + free(_result); + return -1; +} + +/** + * Try to find the symbol closest to an address within a given ELF + * section. + * + * Only function symbols are taken into account. The symbol's address + * must precede `addr`. A symbol with a closer address might exist + * after `addr` but is irrelevant because it cannot encompass `addr`. + * + * On success, if found, the out parameters `sym` and `shdr` are + * set. On failure or if none are found, they remain unchanged. + * + * @param scn ELF section in which to look for the address + * @param addr Virtual memory address for which to find the + * nearest function symbol + * @param sym Out parameter, the nearest function symbol + * @param shdr Out parameter, the section header for scn + * @returns 0 on success, -1 on failure + */ +static +int bin_info_get_nearest_symbol_from_section(Elf_Scn *scn, uint64_t addr, + GElf_Sym **sym, GElf_Shdr **shdr) +{ + int i; + size_t symbol_count; + Elf_Data *data = NULL; + GElf_Shdr *_shdr = NULL; + GElf_Sym *nearest_sym = NULL; + + if (!scn || !sym || !shdr) { + goto error; + } + + _shdr = g_new0(GElf_Shdr, 1); + if (!_shdr) { + goto error; + } + + _shdr = gelf_getshdr(scn, _shdr); + if (!_shdr) { + goto error; + } + + if (_shdr->sh_type != SHT_SYMTAB) { + /* + * We are only interested in symbol table (symtab) + * sections, skip this one. + */ + goto end; + } + + data = elf_getdata(scn, NULL); + if (!data) { + goto error; + } + + symbol_count = _shdr->sh_size / _shdr->sh_entsize; + + for (i = 0; i < symbol_count; ++i) { + GElf_Sym *cur_sym = NULL; + + cur_sym = g_new0(GElf_Sym, 1); + if (!cur_sym) { + goto error; + } + cur_sym = gelf_getsym(data, i, cur_sym); + if (!cur_sym) { + goto error; + } + if (GELF_ST_TYPE(cur_sym->st_info) != STT_FUNC) { + /* We're only interested in the functions. */ + g_free(cur_sym); + continue; + } + + if (cur_sym->st_value <= addr && + (!nearest_sym || + cur_sym->st_value > nearest_sym->st_value)) { + g_free(nearest_sym); + nearest_sym = cur_sym; + } else { + g_free(cur_sym); + } + } + +end: + if (nearest_sym) { + *sym = nearest_sym; + *shdr = _shdr; + } else { + g_free(_shdr); + } + + return 0; + +error: + g_free(nearest_sym); + g_free(_shdr); + return -1; +} + +/** + * Get the name of the function containing a given address within an + * executable using ELF symbols. + * + * The function name is in fact the name of the nearest ELF symbol, + * followed by the offset in bytes between the address and the symbol + * (in hex), separated by a '+' character. + * + * If found, the out parameter `func_name` is set on success. On failure, + * it remains unchanged. + * + * @param bin bin_info instance for the executable containing + * the address + * @param addr Virtual memory address for which to find the + * function name + * @param func_name Out parameter, the function name + * @returns 0 on success, -1 on failure + */ +static +int bin_info_lookup_elf_function_name(struct bin_info *bin, uint64_t addr, + char **func_name) +{ + /* + * TODO (possible optimisation): if an ELF has no symtab + * section, it has been stripped. Therefore, it would be wise + * to store a flag indicating the stripped status after the + * first iteration to prevent subsequent ones. + */ + int ret = 0; + Elf_Scn *scn = NULL; + GElf_Sym *sym = NULL; + GElf_Shdr *shdr = NULL; + char *sym_name = NULL; + + /* Set ELF file if it hasn't been accessed yet. */ + if (!bin->elf_file) { + ret = bin_info_set_elf_file(bin); + if (ret) { + /* Failed to set ELF file. */ + goto error; + } + } + + scn = elf_nextscn(bin->elf_file, scn); + if (!scn) { + goto error; + } + + while (scn && !sym) { + ret = bin_info_get_nearest_symbol_from_section( + scn, addr, &sym, &shdr); + if (ret) { + goto error; + } + + scn = elf_nextscn(bin->elf_file, scn); + } + + if (sym) { + sym_name = elf_strptr(bin->elf_file, shdr->sh_link, + sym->st_name); + if (!sym_name) { + goto error; + } + + ret = bin_info_append_offset_str(sym_name, sym->st_value, addr, + func_name); + if (ret) { + goto error; + } + } + + g_free(shdr); + g_free(sym); + return 0; + +error: + g_free(shdr); + g_free(sym); + return -1; +} + +/** + * Get the name of the function containing a given address within a + * given compile unit (CU). + * + * If found, the out parameter `func_name` is set on success. On + * failure, it remains unchanged. + * + * @param cu bt_dwarf_cu instance which may contain the address + * @param addr Virtual memory address for which to find the + * function name + * @param func_name Out parameter, the function name + * @returns 0 on success, -1 on failure + */ +static +int bin_info_lookup_cu_function_name(struct bt_dwarf_cu *cu, uint64_t addr, + char **func_name) +{ + int ret = 0, found = 0; + struct bt_dwarf_die *die = NULL; + + if (!cu || !func_name) { + goto error; + } + + die = bt_dwarf_die_create(cu); + if (!die) { + goto error; + } + + while (bt_dwarf_die_next(die) == 0) { + int tag; + + ret = bt_dwarf_die_get_tag(die, &tag); + if (ret) { + goto error; + } + + if (tag == DW_TAG_subprogram) { + ret = bt_dwarf_die_contains_addr(die, addr, &found); + if (ret) { + goto error; + } + + if (found) { + break; + } + } + } + + if (found) { + uint64_t low_addr = 0; + char *die_name = NULL; + + ret = bt_dwarf_die_get_name(die, &die_name); + if (ret) { + goto error; + } + + ret = dwarf_lowpc(die->dwarf_die, &low_addr); + if (ret) { + goto error; + } + + ret = bin_info_append_offset_str(die_name, low_addr, addr, + func_name); + if (ret) { + goto error; + } + } + + bt_dwarf_die_destroy(die); + return 0; + +error: + bt_dwarf_die_destroy(die); + return -1; +} + +/** + * Get the name of the function containing a given address within an + * executable using DWARF debug info. + * + * If found, the out parameter `func_name` is set on success. On + * failure, it remains unchanged. + * + * @param bin bin_info instance for the executable containing + * the address + * @param addr Virtual memory address for which to find the + * function name + * @param func_name Out parameter, the function name + * @returns 0 on success, -1 on failure + */ +static +int bin_info_lookup_dwarf_function_name(struct bin_info *bin, uint64_t addr, + char **func_name) +{ + int ret = 0; + char *_func_name = NULL; + struct bt_dwarf_cu *cu = NULL; + + if (!bin || !func_name) { + goto error; + } + + cu = bt_dwarf_cu_create(bin->dwarf_info); + if (!cu) { + goto error; + } + + while (bt_dwarf_cu_next(cu) == 0) { + ret = bin_info_lookup_cu_function_name(cu, addr, &_func_name); + if (ret) { + goto error; + } + + if (_func_name) { + break; + } + } + + if (_func_name) { + *func_name = _func_name; + } + + bt_dwarf_cu_destroy(cu); + return 0; + +error: + bt_dwarf_cu_destroy(cu); + return -1; +} + +BT_HIDDEN +int bin_info_lookup_function_name(struct bin_info *bin, uint64_t addr, + char **func_name) +{ + int ret = 0; + char *_func_name = NULL; + + if (!bin || !func_name) { + goto error; + } + + /* Set DWARF info if it hasn't been accessed yet. */ + if (!bin->dwarf_info && !bin->is_elf_only) { + ret = bin_info_set_dwarf_info(bin); + if (ret) { + /* Failed to set DWARF info, fallback to ELF. */ + bin->is_elf_only = true; + } + } + + if (!bin_info_has_address(bin, addr)) { + goto error; + } + + /* + * Addresses in ELF and DWARF are relative to base address for + * PIC, so make the address argument relative too if needed. + */ + if (bin->is_pic) { + addr -= bin->low_addr; + } + + if (bin->is_elf_only) { + ret = bin_info_lookup_elf_function_name(bin, addr, &_func_name); + } else { + ret = bin_info_lookup_dwarf_function_name(bin, addr, &_func_name); + } + + if (ret || !_func_name) { + goto error; + } + + *func_name = _func_name; + return 0; + +error: + return -1; +} + +BT_HIDDEN +int bin_info_get_bin_loc(struct bin_info *bin, uint64_t addr, char **bin_loc) +{ + int ret = 0; + char *_bin_loc = NULL; + + if (!bin || !bin_loc) { + goto error; + } + + if (bin->is_pic) { + addr -= bin->low_addr; + ret = asprintf(&_bin_loc, "+%#0" PRIx64, addr); + } else { + ret = asprintf(&_bin_loc, "@%#0" PRIx64, addr); + } + + if (ret == -1 || !_bin_loc) { + goto error; + } + + *bin_loc = _bin_loc; + return 0; + +error: + return -1; +} + +/** + * Predicate used to determine whether the children of a given DIE + * contain a specific address. + * + * More specifically, the parameter `die` is expected to be a + * subprogram (function) DIE, and this predicate tells whether any + * subroutines are inlined within this function and would contain + * `addr`. + * + * Do note that this function advances the position of `die`. If the + * address is found within one of its children, `die` will be pointing + * to that child upon returning from the function, allowing to extract + * the information deemed necessary. + * + * @param die The parent DIE in whose children the address will be + * looked for + * @param addr The address for which to look for in the DIEs + * @returns Returns 1 if the address was found, 0 if not + */ +static +int bin_info_child_die_has_address(struct bt_dwarf_die *die, uint64_t addr) +{ + int ret = 0, contains = 0; + + if (!die) { + goto error; + } + + ret = bt_dwarf_die_child(die); + if (ret) { + goto error; + } + + do { + int tag; + + ret = bt_dwarf_die_get_tag(die, &tag); + if (ret) { + goto error; + } + + if (tag == DW_TAG_inlined_subroutine) { + ret = bt_dwarf_die_contains_addr(die, addr, &contains); + if (ret) { + goto error; + } + + if (contains) { + ret = 1; + goto end; + } + } + } while (bt_dwarf_die_next(die) == 0); + +end: + return ret; + +error: + ret = 0; + goto end; +} + +/** + * Lookup the source location for a given address within a CU, making + * the assumption that it is contained within an inline routine in a + * function. + * + * @param cu bt_dwarf_cu instance in which to look for the address + * @param addr The address for which to look for + * @param src_loc Out parameter, the source location (filename and + * line number) for the address + * @returns 0 on success, -1 on failure + */ +static +int bin_info_lookup_cu_src_loc_inl(struct bt_dwarf_cu *cu, uint64_t addr, + struct source_location **src_loc) +{ + int ret = 0, found = 0; + struct bt_dwarf_die *die = NULL; + struct source_location *_src_loc = NULL; + + if (!cu || !src_loc) { + goto error; + } + + die = bt_dwarf_die_create(cu); + if (!die) { + goto error; + } + + while (bt_dwarf_die_next(die) == 0) { + int tag; + + ret = bt_dwarf_die_get_tag(die, &tag); + if (ret) { + goto error; + } + + if (tag == DW_TAG_subprogram) { + int contains = 0; + + ret = bt_dwarf_die_contains_addr(die, addr, &contains); + if (ret) { + goto error; + } + + if (contains) { + /* + * Try to find an inlined subroutine + * child of this DIE containing addr. + */ + found = bin_info_child_die_has_address( + die, addr); + goto end; + } + } + } + +end: + if (found) { + char *filename = NULL; + uint64_t line_no; + + _src_loc = g_new0(struct source_location, 1); + if (!_src_loc) { + goto error; + } + + ret = bt_dwarf_die_get_call_file(die, &filename); + if (ret) { + goto error; + } + ret = bt_dwarf_die_get_call_line(die, &line_no); + if (ret) { + free(filename); + goto error; + } + + _src_loc->filename = filename; + _src_loc->line_no = line_no; + *src_loc = _src_loc; + } + + bt_dwarf_die_destroy(die); + return 0; + +error: + source_location_destroy(_src_loc); + bt_dwarf_die_destroy(die); + return -1; +} + +/** + * Lookup the source location for a given address within a CU, + * assuming that it is contained within an inlined function. + * + * A source location can be found regardless of inlining status for + * this method, but in the case of an inlined function, the returned + * source location will point not to the callsite but rather to the + * definition site of the inline function. + * + * @param cu bt_dwarf_cu instance in which to look for the address + * @param addr The address for which to look for + * @param src_loc Out parameter, the source location (filename and + * line number) for the address + * @returns 0 on success, -1 on failure + */ +static +int bin_info_lookup_cu_src_loc_no_inl(struct bt_dwarf_cu *cu, uint64_t addr, + struct source_location **src_loc) +{ + struct source_location *_src_loc = NULL; + struct bt_dwarf_die *die = NULL; + const char *filename = NULL; + Dwarf_Line *line = NULL; + Dwarf_Addr line_addr; + int ret, line_no; + + if (!cu || !src_loc) { + goto error; + } + + die = bt_dwarf_die_create(cu); + if (!die) { + goto error; + } + + line = dwarf_getsrc_die(die->dwarf_die, addr); + if (!line) { + goto error; + } + + ret = dwarf_lineaddr(line, &line_addr); + if (ret) { + goto error; + } + + filename = dwarf_linesrc(line, NULL, NULL); + if (!filename) { + goto error; + } + + if (addr == line_addr) { + _src_loc = g_new0(struct source_location, 1); + if (!_src_loc) { + goto error; + } + + ret = dwarf_lineno(line, &line_no); + if (ret) { + goto error; + } + + _src_loc->line_no = line_no; + _src_loc->filename = strdup(filename); + } + + bt_dwarf_die_destroy(die); + + if (_src_loc) { + *src_loc = _src_loc; + } + + return 0; + +error: + source_location_destroy(_src_loc); + bt_dwarf_die_destroy(die); + return -1; +} + +/** + * Get the source location (file name and line number) for a given + * address within a compile unit (CU). + * + * On success, the out parameter `src_loc` is set if found. On + * failure, it remains unchanged. + * + * @param cu bt_dwarf_cu instance for the compile unit which + * may contain the address + * @param addr Virtual memory address for which to find the + * source location + * @param src_loc Out parameter, the source location + * @returns 0 on success, -1 on failure + */ +static +int bin_info_lookup_cu_src_loc(struct bt_dwarf_cu *cu, uint64_t addr, + struct source_location **src_loc) +{ + int ret = 0; + struct source_location *_src_loc = NULL; + + if (!cu || !src_loc) { + goto error; + } + + ret = bin_info_lookup_cu_src_loc_inl(cu, addr, &_src_loc); + if (ret) { + goto error; + } + + if (_src_loc) { + goto end; + } + + ret = bin_info_lookup_cu_src_loc_no_inl(cu, addr, &_src_loc); + if (ret) { + goto error; + } + + if (_src_loc) { + goto end; + } + +end: + if (_src_loc) { + *src_loc = _src_loc; + } + + return 0; + +error: + source_location_destroy(_src_loc); + return -1; +} + +BT_HIDDEN +int bin_info_lookup_source_location(struct bin_info *bin, uint64_t addr, + struct source_location **src_loc) +{ + struct bt_dwarf_cu *cu = NULL; + struct source_location *_src_loc = NULL; + + if (!bin || !src_loc) { + goto error; + } + + /* Set DWARF info if it hasn't been accessed yet. */ + if (!bin->dwarf_info && !bin->is_elf_only) { + if (bin_info_set_dwarf_info(bin)) { + /* Failed to set DWARF info. */ + bin->is_elf_only = true; + } + } + + if (bin->is_elf_only) { + /* We cannot lookup source location without DWARF info. */ + goto error; + } + + if (!bin_info_has_address(bin, addr)) { + goto error; + } + + /* + * Addresses in ELF and DWARF are relative to base address for + * PIC, so make the address argument relative too if needed. + */ + if (bin->is_pic) { + addr -= bin->low_addr; + } + + cu = bt_dwarf_cu_create(bin->dwarf_info); + if (!cu) { + goto error; + } + + while (bt_dwarf_cu_next(cu) == 0) { + int ret; + + ret = bin_info_lookup_cu_src_loc(cu, addr, &_src_loc); + if (ret) { + goto error; + } + + if (_src_loc) { + break; + } + } + + bt_dwarf_cu_destroy(cu); + if (_src_loc) { + *src_loc = _src_loc; + } + + return 0; + +error: + source_location_destroy(_src_loc); + bt_dwarf_cu_destroy(cu); + return -1; +}