blob: 8b38b5d6fec7b586482b138d6899a776e538bec2 [file] [log] [blame]
// SPDX-License-Identifier: GPL-2.0-or-later
* Copyright (C) 2015-2017 Josh Poimboeuf <>
* objtool check:
* This command analyzes every .o file and ensures the validity of its stack
* trace metadata. It enforces a set of rules on asm code and C inline
* assembly code so that stack traces can be reliable.
* For more information, see tools/objtool/Documentation/stack-validation.txt.
#include <subcmd/parse-options.h>
#include <string.h>
#include <stdlib.h>
#include <objtool/builtin.h>
#include <objtool/objtool.h>
bool no_fp, no_unreachable, retpoline, module, backtrace, uaccess, stats,
validate_dup, vmlinux, mcount, noinstr, backup;
static const char * const check_usage[] = {
"objtool check [<options>] file.o",
static const char * const env_usage[] = {
const struct option check_options[] = {
OPT_BOOLEAN('f', "no-fp", &no_fp, "Skip frame pointer validation"),
OPT_BOOLEAN('u', "no-unreachable", &no_unreachable, "Skip 'unreachable instruction' warnings"),
OPT_BOOLEAN('r', "retpoline", &retpoline, "Validate retpoline assumptions"),
OPT_BOOLEAN('m', "module", &module, "Indicates the object will be part of a kernel module"),
OPT_BOOLEAN('b', "backtrace", &backtrace, "unwind on error"),
OPT_BOOLEAN('a', "uaccess", &uaccess, "enable uaccess checking"),
OPT_BOOLEAN('s', "stats", &stats, "print statistics"),
OPT_BOOLEAN('d', "duplicate", &validate_dup, "duplicate validation for vmlinux.o"),
OPT_BOOLEAN('n', "noinstr", &noinstr, "noinstr validation for vmlinux.o"),
OPT_BOOLEAN('l', "vmlinux", &vmlinux, "vmlinux.o validation"),
OPT_BOOLEAN('M', "mcount", &mcount, "generate __mcount_loc"),
OPT_BOOLEAN('B', "backup", &backup, "create .orig files before modification"),
int cmd_parse_options(int argc, const char **argv, const char * const usage[])
const char *envv[16] = { };
char *env;
int envc;
env = getenv("OBJTOOL_ARGS");
if (env) {
envv[0] = "OBJTOOL_ARGS";
for (envc = 1; envc < ARRAY_SIZE(envv); ) {
envv[envc++] = env;
env = strchr(env, ' ');
if (!env)
*env = '\0';
parse_options(envc, envv, check_options, env_usage, 0);
argc = parse_options(argc, argv, check_options, usage, 0);
if (argc != 1)
usage_with_options(usage, check_options);
return argc;
int cmd_check(int argc, const char **argv)
const char *objname;
struct objtool_file *file;
int ret;
argc = cmd_parse_options(argc, argv, check_usage);
objname = argv[0];
file = objtool_open_read(objname);
if (!file)
return 1;
ret = check(file);
if (ret)
return ret;
if (file->elf->changed)
return elf_write(file->elf);
return 0;