1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * Copyright (C) 2015-2017 Josh Poimboeuf <jpoimboe@redhat.com> 4 */ 5 6 #include <subcmd/parse-options.h> 7 #include <string.h> 8 #include <stdlib.h> 9 #include <objtool/builtin.h> 10 #include <objtool/objtool.h> 11 12 #define ERROR(format, ...) \ 13 fprintf(stderr, \ 14 "error: objtool: " format "\n", \ 15 ##__VA_ARGS__) 16 17 struct opts opts; 18 19 static const char * const check_usage[] = { 20 "objtool <actions> [<options>] file.o", 21 NULL, 22 }; 23 24 static const char * const env_usage[] = { 25 "OBJTOOL_ARGS=\"<options>\"", 26 NULL, 27 }; 28 29 static int parse_dump(const struct option *opt, const char *str, int unset) 30 { 31 if (!str || !strcmp(str, "orc")) { 32 opts.dump_orc = true; 33 return 0; 34 } 35 36 return -1; 37 } 38 39 static int parse_hacks(const struct option *opt, const char *str, int unset) 40 { 41 bool found = false; 42 43 /* 44 * Use strstr() as a lazy method of checking for comma-separated 45 * options. 46 * 47 * No string provided == enable all options. 48 */ 49 50 if (!str || strstr(str, "jump_label")) { 51 opts.hack_jump_label = true; 52 found = true; 53 } 54 55 if (!str || strstr(str, "noinstr")) { 56 opts.hack_noinstr = true; 57 found = true; 58 } 59 60 if (!str || strstr(str, "skylake")) { 61 opts.hack_skylake = true; 62 found = true; 63 } 64 65 return found ? 0 : -1; 66 } 67 68 const struct option check_options[] = { 69 OPT_GROUP("Actions:"), 70 OPT_CALLBACK_OPTARG('h', "hacks", NULL, NULL, "jump_label,noinstr,skylake", "patch toolchain bugs/limitations", parse_hacks), 71 OPT_BOOLEAN('i', "ibt", &opts.ibt, "validate and annotate IBT"), 72 OPT_BOOLEAN('m', "mcount", &opts.mcount, "annotate mcount/fentry calls for ftrace"), 73 OPT_BOOLEAN('n', "noinstr", &opts.noinstr, "validate noinstr rules"), 74 OPT_BOOLEAN('o', "orc", &opts.orc, "generate ORC metadata"), 75 OPT_BOOLEAN('r', "retpoline", &opts.retpoline, "validate and annotate retpoline usage"), 76 OPT_BOOLEAN(0, "rethunk", &opts.rethunk, "validate and annotate rethunk usage"), 77 OPT_BOOLEAN(0, "unret", &opts.unret, "validate entry unret placement"), 78 OPT_INTEGER(0, "prefix", &opts.prefix, "generate prefix symbols"), 79 OPT_BOOLEAN('l', "sls", &opts.sls, "validate straight-line-speculation mitigations"), 80 OPT_BOOLEAN('s', "stackval", &opts.stackval, "validate frame pointer rules"), 81 OPT_BOOLEAN('t', "static-call", &opts.static_call, "annotate static calls"), 82 OPT_BOOLEAN('u', "uaccess", &opts.uaccess, "validate uaccess rules for SMAP"), 83 OPT_BOOLEAN(0 , "cfi", &opts.cfi, "annotate kernel control flow integrity (kCFI) function preambles"), 84 OPT_CALLBACK_OPTARG(0, "dump", NULL, NULL, "orc", "dump metadata", parse_dump), 85 86 OPT_GROUP("Options:"), 87 OPT_BOOLEAN(0, "backtrace", &opts.backtrace, "unwind on error"), 88 OPT_BOOLEAN(0, "backup", &opts.backup, "create .orig files before modification"), 89 OPT_BOOLEAN(0, "dry-run", &opts.dryrun, "don't write modifications"), 90 OPT_BOOLEAN(0, "link", &opts.link, "object is a linked object"), 91 OPT_BOOLEAN(0, "module", &opts.module, "object is part of a kernel module"), 92 OPT_BOOLEAN(0, "mnop", &opts.mnop, "nop out mcount call sites"), 93 OPT_BOOLEAN(0, "no-unreachable", &opts.no_unreachable, "skip 'unreachable instruction' warnings"), 94 OPT_BOOLEAN(0, "sec-address", &opts.sec_address, "print section addresses in warnings"), 95 OPT_BOOLEAN(0, "stats", &opts.stats, "print statistics"), 96 97 OPT_END(), 98 }; 99 100 int cmd_parse_options(int argc, const char **argv, const char * const usage[]) 101 { 102 const char *envv[16] = { }; 103 char *env; 104 int envc; 105 106 env = getenv("OBJTOOL_ARGS"); 107 if (env) { 108 envv[0] = "OBJTOOL_ARGS"; 109 for (envc = 1; envc < ARRAY_SIZE(envv); ) { 110 envv[envc++] = env; 111 env = strchr(env, ' '); 112 if (!env) 113 break; 114 *env = '\0'; 115 env++; 116 } 117 118 parse_options(envc, envv, check_options, env_usage, 0); 119 } 120 121 argc = parse_options(argc, argv, check_options, usage, 0); 122 if (argc != 1) 123 usage_with_options(usage, check_options); 124 return argc; 125 } 126 127 static bool opts_valid(void) 128 { 129 if (opts.hack_jump_label || 130 opts.hack_noinstr || 131 opts.ibt || 132 opts.mcount || 133 opts.noinstr || 134 opts.orc || 135 opts.retpoline || 136 opts.rethunk || 137 opts.sls || 138 opts.stackval || 139 opts.static_call || 140 opts.uaccess) { 141 if (opts.dump_orc) { 142 ERROR("--dump can't be combined with other options"); 143 return false; 144 } 145 146 return true; 147 } 148 149 if (opts.unret && !opts.rethunk) { 150 ERROR("--unret requires --rethunk"); 151 return false; 152 } 153 154 if (opts.dump_orc) 155 return true; 156 157 ERROR("At least one command required"); 158 return false; 159 } 160 161 static bool mnop_opts_valid(void) 162 { 163 if (opts.mnop && !opts.mcount) { 164 ERROR("--mnop requires --mcount"); 165 return false; 166 } 167 168 return true; 169 } 170 171 static bool link_opts_valid(struct objtool_file *file) 172 { 173 if (opts.link) 174 return true; 175 176 if (has_multiple_files(file->elf)) { 177 ERROR("Linked object detected, forcing --link"); 178 opts.link = true; 179 return true; 180 } 181 182 if (opts.noinstr) { 183 ERROR("--noinstr requires --link"); 184 return false; 185 } 186 187 if (opts.ibt) { 188 ERROR("--ibt requires --link"); 189 return false; 190 } 191 192 if (opts.unret) { 193 ERROR("--unret requires --link"); 194 return false; 195 } 196 197 return true; 198 } 199 200 int objtool_run(int argc, const char **argv) 201 { 202 const char *objname; 203 struct objtool_file *file; 204 int ret; 205 206 argc = cmd_parse_options(argc, argv, check_usage); 207 objname = argv[0]; 208 209 if (!opts_valid()) 210 return 1; 211 212 if (opts.dump_orc) 213 return orc_dump(objname); 214 215 file = objtool_open_read(objname); 216 if (!file) 217 return 1; 218 219 if (!mnop_opts_valid()) 220 return 1; 221 222 if (!link_opts_valid(file)) 223 return 1; 224 225 ret = check(file); 226 if (ret) 227 return ret; 228 229 if (file->elf->changed) 230 return elf_write(file->elf); 231 232 return 0; 233 } 234