1 files changed, 238 insertions, 0 deletions
diff --git a/tools/objtool/builtin-check.c b/tools/objtool/builtin-check.c
new file mode 100644
index 0000000000..5e21cfb766
--- /dev/null
+++ b/tools/objtool/builtin-check.c
@@ -0,0 +1,238 @@
+// 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_BOOLEAN('v', "verbose", &opts.verbose, "verbose warnings"),
+
+	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);
+	}
+
+	env = getenv("OBJTOOL_VERBOSE");
+	if (env && !strcmp(env, "1"))
+		opts.verbose = true;
+
+	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;
+}