Commit b51277eb authored by Josh Poimboeuf's avatar Josh Poimboeuf Committed by Peter Zijlstra
Browse files

objtool: Ditch subcommands 



Objtool has a fairly singular focus.  It runs on object files and does
validations and transformations which can be combined in various ways.
The subcommand model has never been a good fit, making it awkward to
combine and remove options.

Remove the "check" and "orc" subcommands in favor of a more traditional
cmdline option model.  This makes it much more flexible to use, and
easier to port individual features to other arches.

Signed-off-by: default avatarJosh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: default avatarMiroslav Benes <mbenes@suse.cz>
Link: https://lkml.kernel.org/r/5c61ebf805e90aefc5fa62bc63468ffae53b9df6.1650300597.git.jpoimboe@redhat.com
parent 2daf7fab

scripts/Makefile.build

+1 −1
Original line number Diff line number Diff line
@@ -227,9 +227,9 @@ ifdef CONFIG_STACK_VALIDATION 
objtool := $(objtree)/tools/objtool/objtool



objtool_args =								\

	$(if $(CONFIG_UNWINDER_ORC),orc generate,check)			\

	$(if $(CONFIG_X86_KERNEL_IBT), --lto --ibt)			\

	$(if $(CONFIG_FTRACE_MCOUNT_USE_OBJTOOL), --mcount)		\

	$(if $(CONFIG_UNWINDER_ORC), --orc)				\

	$(if $(CONFIG_RETPOLINE), --retpoline)				\

	$(if $(CONFIG_SLS), --sls)					\

	$(if $(CONFIG_X86_SMAP), --uaccess)				\

scripts/link-vmlinux.sh

+5 −8
Original line number Diff line number Diff line
@@ -113,9 +113,6 @@ objtool_link() 


		# Don't perform vmlinux validation unless explicitly requested,

		# but run objtool on vmlinux.o now that we have an object file.

		if is_enabled CONFIG_UNWINDER_ORC; then

			objtoolcmd="orc generate"

		fi



		if is_enabled CONFIG_X86_KERNEL_IBT; then

			objtoolopt="${objtoolopt} --ibt"
@@ -125,6 +122,10 @@ objtool_link() 
			objtoolopt="${objtoolopt} --mcount"

		fi



		if is_enabled CONFIG_UNWINDER_ORC; then

			objtoolopt="${objtoolopt} --orc"

		fi



		objtoolopt="${objtoolopt} --lto"

	fi
@@ -134,10 +135,6 @@ objtool_link() 


	if [ -n "${objtoolopt}" ]; then



		if [ -z "${objtoolcmd}" ]; then

			objtoolcmd="check"

		fi



		if is_enabled CONFIG_RETPOLINE; then

			objtoolopt="${objtoolopt} --retpoline"

		fi
@@ -161,7 +158,7 @@ objtool_link() 
		objtoolopt="${objtoolopt} --vmlinux"



		info OBJTOOL ${1}

		tools/objtool/objtool ${objtoolcmd} ${objtoolopt} ${1}

		tools/objtool/objtool ${objtoolopt} ${1}

	fi

}

tools/objtool/Build

+5 −7
Original line number Diff line number Diff line
@@ -2,17 +2,15 @@ objtool-y += arch/$(SRCARCH)/ 


objtool-y += weak.o



objtool-$(SUBCMD_CHECK) += check.o

objtool-$(SUBCMD_CHECK) += special.o

objtool-$(SUBCMD_ORC) += check.o

objtool-$(SUBCMD_ORC) += orc_gen.o

objtool-$(SUBCMD_ORC) += orc_dump.o



objtool-y += check.o

objtool-y += special.o

objtool-y += builtin-check.o

objtool-y += builtin-orc.o

objtool-y += elf.o

objtool-y += objtool.o



objtool-$(BUILD_ORC) += orc_gen.o

objtool-$(BUILD_ORC) += orc_dump.o



objtool-y += libstring.o

objtool-y += libctype.o

objtool-y += str_error_r.o

tools/objtool/Makefile

+3 −5
Original line number Diff line number Diff line
@@ -39,15 +39,13 @@ CFLAGS += $(if $(elfshdr),,-DLIBELF_USE_DEPRECATED) 


AWK = awk



SUBCMD_CHECK := n

SUBCMD_ORC := n

BUILD_ORC := n



ifeq ($(SRCARCH),x86)

	SUBCMD_CHECK := y

	SUBCMD_ORC := y

	BUILD_ORC := y

endif



export SUBCMD_CHECK SUBCMD_ORC

export BUILD_ORC

export srctree OUTPUT CFLAGS SRCARCH AWK

include $(srctree)/tools/build/Makefile.include

tools/objtool/builtin-check.c

+44 −12
Original line number Diff line number Diff line
@@ -3,16 +3,6 @@ 
 * Copyright (C) 2015-2017 Josh Poimboeuf <jpoimboe@redhat.com>

 */



/*

 * objtool check:

 *

 * This command analyzes every .o file and ensures the validity of its stack

 * trace metadata.  It enforces a set of rules on asm code and C inline

 * assembly code so that stack traces can be reliable.

 *

 * For more information, see tools/objtool/Documentation/stack-validation.txt.

 */



#include <subcmd/parse-options.h>

#include <string.h>

#include <stdlib.h>
@@ -22,7 +12,7 @@ 
struct opts opts;



static const char * const check_usage[] = {

	"objtool check <actions> [<options>] file.o",

	"objtool <actions> [<options>] file.o",

	NULL,

};
@@ -31,14 +21,26 @@ static const char * const env_usage[] = { 
	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;

}



const struct option check_options[] = {

	OPT_GROUP("Actions:"),

	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('l', "sls", &opts.sls, "validate straight-line-speculation mitigations"),

	OPT_BOOLEAN('u', "uaccess", &opts.uaccess, "validate uaccess rules for SMAP"),

	OPT_CALLBACK_OPTARG(0, "dump", NULL, NULL, "orc", "dump metadata", parse_dump),



	OPT_GROUP("Options:"),

	OPT_BOOLEAN(0, "backtrace", &opts.backtrace, "unwind on error"),
@@ -81,7 +83,31 @@ int cmd_parse_options(int argc, const char **argv, const char * const usage[]) 
	return argc;

}



int cmd_check(int argc, const char **argv)

static bool opts_valid(void)

{

	if (opts.ibt		||

	    opts.mcount		||

	    opts.noinstr	||

	    opts.orc		||

	    opts.retpoline	||

	    opts.sls		||

	    opts.uaccess) {

		if (opts.dump_orc) {

			fprintf(stderr, "--dump can't be combined with other options\n");

			return false;

		}



		return true;

	}



	if (opts.dump_orc)

		return true;



	fprintf(stderr, "At least one command required\n");

	return false;

}



int objtool_run(int argc, const char **argv)

{

	const char *objname;

	struct objtool_file *file;
@@ -90,6 +116,12 @@ int cmd_check(int argc, const char **argv) 
	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;