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 static 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 OPT_BOOLEAN('v', "verbose", &opts.verbose, "verbose warnings"), 97 98 OPT_END(), 99 }; 100 101 int cmd_parse_options(int argc, const char **argv, const char * const usage[]) 102 { 103 const char *envv[16] = { }; 104 char *env; 105 int envc; 106 107 env = getenv("OBJTOOL_ARGS"); 108 if (env) { 109 envv[0] = "OBJTOOL_ARGS"; 110 for (envc = 1; envc < ARRAY_SIZE(envv); ) { 111 envv[envc++] = env; 112 env = strchr(env, ' '); 113 if (!env) 114 break; 115 *env = '\0'; 116 env++; 117 } 118 119 parse_options(envc, envv, check_options, env_usage, 0); 120 } 121 122 env = getenv("OBJTOOL_VERBOSE"); 123 if (env && !strcmp(env, "1")) 124 opts.verbose = true; 125 126 argc = parse_options(argc, argv, check_options, usage, 0); 127 if (argc != 1) 128 usage_with_options(usage, check_options); 129 return argc; 130 } 131 132 static bool opts_valid(void) 133 { 134 if (opts.hack_jump_label || 135 opts.hack_noinstr || 136 opts.ibt || 137 opts.mcount || 138 opts.noinstr || 139 opts.orc || 140 opts.retpoline || 141 opts.rethunk || 142 opts.sls || 143 opts.stackval || 144 opts.static_call || 145 opts.uaccess) { 146 if (opts.dump_orc) { 147 ERROR("--dump can't be combined with other options"); 148 return false; 149 } 150 151 return true; 152 } 153 154 if (opts.unret && !opts.rethunk) { 155 ERROR("--unret requires --rethunk"); 156 return false; 157 } 158 159 if (opts.dump_orc) 160 return true; 161 162 ERROR("At least one command required"); 163 return false; 164 } 165 166 static bool mnop_opts_valid(void) 167 { 168 if (opts.mnop && !opts.mcount) { 169 ERROR("--mnop requires --mcount"); 170 return false; 171 } 172 173 return true; 174 } 175 176 static bool link_opts_valid(struct objtool_file *file) 177 { 178 if (opts.link) 179 return true; 180 181 if (has_multiple_files(file->elf)) { 182 ERROR("Linked object detected, forcing --link"); 183 opts.link = true; 184 return true; 185 } 186 187 if (opts.noinstr) { 188 ERROR("--noinstr requires --link"); 189 return false; 190 } 191 192 if (opts.ibt) { 193 ERROR("--ibt requires --link"); 194 return false; 195 } 196 197 if (opts.unret) { 198 ERROR("--unret requires --link"); 199 return false; 200 } 201 202 return true; 203 } 204 205 int objtool_run(int argc, const char **argv) 206 { 207 const char *objname; 208 struct objtool_file *file; 209 int ret; 210 211 argc = cmd_parse_options(argc, argv, check_usage); 212 objname = argv[0]; 213 214 if (!opts_valid()) 215 return 1; 216 217 if (opts.dump_orc) 218 return orc_dump(objname); 219 220 file = objtool_open_read(objname); 221 if (!file) 222 return 1; 223 224 if (!mnop_opts_valid()) 225 return 1; 226 227 if (!link_opts_valid(file)) 228 return 1; 229 230 ret = check(file); 231 if (ret) 232 return ret; 233 234 if (file->elf->changed) 235 return elf_write(file->elf); 236 237 return 0; 238 } 239