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// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Copyright (C) 2015-2017 Josh Poimboeuf <jpoimboe@redhat.com>
*/
#include <subcmd/parse-options.h>
#include <string.h>
#include <stdlib.h>
#include <objtool/builtin.h>
#include <objtool/objtool.h>
#define ERROR(format, ...) \
fprintf(stderr, \
"error: objtool: " format "\n", \
##__VA_ARGS__)
struct opts opts;
static const char * const check_usage[] = {
"objtool <actions> [<options>] file.o",
NULL,
};
static const char * const env_usage[] = {
"OBJTOOL_ARGS=\"<options>\"",
NULL,
};
static int parse_dump(const struct option *opt, const char *str, int unset)
{
if (!str || !strcmp(str, "orc")) {
opts.dump_orc = true;
return 0;
}
return -1;
}
static int parse_hacks(const struct option *opt, const char *str, int unset)
{
bool found = false;
/*
* Use strstr() as a lazy method of checking for comma-separated
* options.
*
* No string provided == enable all options.
*/
if (!str || strstr(str, "jump_label")) {
opts.hack_jump_label = true;
found = true;
}
if (!str || strstr(str, "noinstr")) {
opts.hack_noinstr = true;
found = true;
}
if (!str || strstr(str, "skylake")) {
opts.hack_skylake = true;
found = true;
}
return found ? 0 : -1;
}
static const struct option check_options[] = {
OPT_GROUP("Actions:"),
OPT_CALLBACK_OPTARG('h', "hacks", NULL, NULL, "jump_label,noinstr,skylake", "patch toolchain bugs/limitations", parse_hacks),
OPT_BOOLEAN('i', "ibt", &opts.ibt, "validate and annotate IBT"),
OPT_BOOLEAN('m', "mcount", &opts.mcount, "annotate mcount/fentry calls for ftrace"),
OPT_BOOLEAN('n', "noinstr", &opts.noinstr, "validate noinstr rules"),
OPT_BOOLEAN('o', "orc", &opts.orc, "generate ORC metadata"),
OPT_BOOLEAN('r', "retpoline", &opts.retpoline, "validate and annotate retpoline usage"),
OPT_BOOLEAN(0, "rethunk", &opts.rethunk, "validate and annotate rethunk usage"),
OPT_BOOLEAN(0, "unret", &opts.unret, "validate entry unret placement"),
OPT_INTEGER(0, "prefix", &opts.prefix, "generate prefix symbols"),
OPT_BOOLEAN('l', "sls", &opts.sls, "validate straight-line-speculation mitigations"),
OPT_BOOLEAN('s', "stackval", &opts.stackval, "validate frame pointer rules"),
OPT_BOOLEAN('t', "static-call", &opts.static_call, "annotate static calls"),
OPT_BOOLEAN('u', "uaccess", &opts.uaccess, "validate uaccess rules for SMAP"),
OPT_BOOLEAN(0 , "cfi", &opts.cfi, "annotate kernel control flow integrity (kCFI) function preambles"),
OPT_CALLBACK_OPTARG(0, "dump", NULL, NULL, "orc", "dump metadata", parse_dump),
OPT_GROUP("Options:"),
OPT_BOOLEAN(0, "backtrace", &opts.backtrace, "unwind on error"),
OPT_BOOLEAN(0, "backup", &opts.backup, "create .orig files before modification"),
OPT_BOOLEAN(0, "dry-run", &opts.dryrun, "don't write modifications"),
OPT_BOOLEAN(0, "link", &opts.link, "object is a linked object"),
OPT_BOOLEAN(0, "module", &opts.module, "object is part of a kernel module"),
OPT_BOOLEAN(0, "mnop", &opts.mnop, "nop out mcount call sites"),
OPT_BOOLEAN(0, "no-unreachable", &opts.no_unreachable, "skip 'unreachable instruction' warnings"),
OPT_BOOLEAN(0, "sec-address", &opts.sec_address, "print section addresses in warnings"),
OPT_BOOLEAN(0, "stats", &opts.stats, "print statistics"),
OPT_END(),
};
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)
break;
*env = '\0';
env++;
}
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;
}
static bool opts_valid(void)
{
if (opts.hack_jump_label ||
opts.hack_noinstr ||
opts.ibt ||
opts.mcount ||
opts.noinstr ||
opts.orc ||
opts.retpoline ||
opts.rethunk ||
opts.sls ||
opts.stackval ||
opts.static_call ||
opts.uaccess) {
if (opts.dump_orc) {
ERROR("--dump can't be combined with other options");
return false;
}
return true;
}
if (opts.unret && !opts.rethunk) {
ERROR("--unret requires --rethunk");
return false;
}
if (opts.dump_orc)
return true;
ERROR("At least one command required");
return false;
}
static bool mnop_opts_valid(void)
{
if (opts.mnop && !opts.mcount) {
ERROR("--mnop requires --mcount");
return false;
}
return true;
}
static bool link_opts_valid(struct objtool_file *file)
{
if (opts.link)
return true;
if (has_multiple_files(file->elf)) {
ERROR("Linked object detected, forcing --link");
opts.link = true;
return true;
}
if (opts.noinstr) {
ERROR("--noinstr requires --link");
return false;
}
if (opts.ibt) {
ERROR("--ibt requires --link");
return false;
}
if (opts.unret) {
ERROR("--unret requires --link");
return false;
}
return true;
}
int objtool_run(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];
if (!opts_valid())
return 1;
if (opts.dump_orc)
return orc_dump(objname);
file = objtool_open_read(objname);
if (!file)
return 1;
if (!mnop_opts_valid())
return 1;
if (!link_opts_valid(file))
return 1;
ret = check(file);
if (ret)
return ret;
if (file->elf->changed)
return elf_write(file->elf);
return 0;
}
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