1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * Copyright (C) 2015-2017 Josh Poimboeuf <jpoimboe@redhat.com> 4 */ 5 6 /* 7 * objtool check: 8 * 9 * This command analyzes every .o file and ensures the validity of its stack 10 * trace metadata. It enforces a set of rules on asm code and C inline 11 * assembly code so that stack traces can be reliable. 12 * 13 * For more information, see tools/objtool/Documentation/stack-validation.txt. 14 */ 15 16 #include <subcmd/parse-options.h> 17 #include <string.h> 18 #include <stdlib.h> 19 #include <objtool/builtin.h> 20 #include <objtool/objtool.h> 21 22 bool no_fp, no_unreachable, retpoline, module, backtrace, uaccess, stats, 23 validate_dup, vmlinux, mcount, noinstr, backup; 24 25 static const char * const check_usage[] = { 26 "objtool check [<options>] file.o", 27 NULL, 28 }; 29 30 static const char * const env_usage[] = { 31 "OBJTOOL_ARGS=\"<options>\"", 32 NULL, 33 }; 34 35 const struct option check_options[] = { 36 OPT_BOOLEAN('f', "no-fp", &no_fp, "Skip frame pointer validation"), 37 OPT_BOOLEAN('u', "no-unreachable", &no_unreachable, "Skip 'unreachable instruction' warnings"), 38 OPT_BOOLEAN('r', "retpoline", &retpoline, "Validate retpoline assumptions"), 39 OPT_BOOLEAN('m', "module", &module, "Indicates the object will be part of a kernel module"), 40 OPT_BOOLEAN('b', "backtrace", &backtrace, "unwind on error"), 41 OPT_BOOLEAN('a', "uaccess", &uaccess, "enable uaccess checking"), 42 OPT_BOOLEAN('s', "stats", &stats, "print statistics"), 43 OPT_BOOLEAN('d', "duplicate", &validate_dup, "duplicate validation for vmlinux.o"), 44 OPT_BOOLEAN('n', "noinstr", &noinstr, "noinstr validation for vmlinux.o"), 45 OPT_BOOLEAN('l', "vmlinux", &vmlinux, "vmlinux.o validation"), 46 OPT_BOOLEAN('M', "mcount", &mcount, "generate __mcount_loc"), 47 OPT_BOOLEAN('B', "backup", &backup, "create .orig files before modification"), 48 OPT_END(), 49 }; 50 51 int cmd_parse_options(int argc, const char **argv, const char * const usage[]) 52 { 53 const char *envv[16] = { }; 54 char *env; 55 int envc; 56 57 env = getenv("OBJTOOL_ARGS"); 58 if (env) { 59 envv[0] = "OBJTOOL_ARGS"; 60 for (envc = 1; envc < ARRAY_SIZE(envv); ) { 61 envv[envc++] = env; 62 env = strchr(env, ' '); 63 if (!env) 64 break; 65 *env = '\0'; 66 env++; 67 } 68 69 parse_options(envc, envv, check_options, env_usage, 0); 70 } 71 72 argc = parse_options(argc, argv, check_options, usage, 0); 73 if (argc != 1) 74 usage_with_options(usage, check_options); 75 return argc; 76 } 77 78 int cmd_check(int argc, const char **argv) 79 { 80 const char *objname; 81 struct objtool_file *file; 82 int ret; 83 84 argc = cmd_parse_options(argc, argv, check_usage); 85 objname = argv[0]; 86 87 file = objtool_open_read(objname); 88 if (!file) 89 return 1; 90 91 ret = check(file); 92 if (ret) 93 return ret; 94 95 if (file->elf->changed) 96 return elf_write(file->elf); 97 98 return 0; 99 } 100