/*
* bin-info.c
*
* Babeltrace - Executable and Shared Object Debug Info Reader
*
* Copyright 2015 Antoine Busque <abusque@efficios.com>
*
* Author: Antoine Busque <abusque@efficios.com>
*
* 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 <fcntl.h>
#include <math.h>
#include <libgen.h>
#include <stdio.h>
#include <inttypes.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <dwarf.h>
#include <glib.h>
#include <babeltrace/dwarf.h>
#include <babeltrace/bin-info.h>
#include <babeltrace/crc32.h>
#include <babeltrace/babeltrace-internal.h>
#include <babeltrace/utils.h>
#include <errno.h>
/*
* 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, negative value 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) {
fd = -errno;
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:
if (fd >= 0) {
close(fd);
fd = -1;
}
dwarf_end(dwarf_info);
g_free(dwarf_info);
free(cu);
return fd;
}
/**
* 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_noclose;
}
fd = open(path, O_RDONLY);
if (fd < 0) {
goto end_noclose;
}
ret = crc32(fd, &_crc);
if (ret) {
ret = 0;
goto end;
}
ret = (crc == _crc);
end:
close(fd);
end_noclose:
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, negative value on failure
*/
static
int bin_info_set_dwarf_info(struct bin_info *bin)
{
int ret = 0;
if (!bin) {
ret = -1;
goto end;
}
/* 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;
}
end:
return ret;
}
/**
* Initialize the ELF file for a given executable.
*
* @param bin bin_info instance
* @returns 0 on success, negative value on error.
*/
static
int bin_info_set_elf_file(struct bin_info *bin)
{
int elf_fd = -1;
Elf *elf_file = NULL;
if (!bin) {
goto error;
}
elf_fd = open(bin->elf_path, O_RDONLY);
if (elf_fd < 0) {
elf_fd = -errno;
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:
if (elf_fd >= 0) {
close(elf_fd);
elf_fd = -1;
}
elf_end(elf_file);
return elf_fd;
}
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 ret;
}
/**
* 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;
bool found = false;
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) {
free(die_name);
goto error;
}
ret = bin_info_append_offset_str(die_name, low_addr, addr,
func_name);
free(die_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;
} else {
goto error;
}
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) {
printf_verbose("Failed to set bin dwarf info, falling back to ELF lookup.\n");
/* 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);
printf_verbose("Failed to lookup function name (elf), error %i\n", ret);
} else {
ret = bin_info_lookup_dwarf_function_name(bin, addr, &_func_name);
printf_verbose("Failed to lookup function name (dwarf), error %i\n", ret);
}
*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`.
*
* On success, the out parameter `contains` is set with the boolean
* value indicating whether the DIE's range covers `addr`. On failure,
* it remains unchanged.
*
* 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
* @param contains Out parameter, true if addr is contained,
* false if not
* @returns Returns 0 on success, -1 on failure
*/
static
int bin_info_child_die_has_address(struct bt_dwarf_die *die, uint64_t addr, bool *contains)
{
int ret = 0;
bool _contains = false;
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) {
goto end;
}
}
} while (bt_dwarf_die_next(die) == 0);
end:
*contains = _contains;
return 0;
error:
return -1;
}
/**
* 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;
bool found = false;
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) {
bool contains = false;
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.
*/
ret = bin_info_child_die_has_address(die, addr,
&found);
if(ret) {
goto error;
}
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;
}