mirrors/linux
1
0
Fork 1
mirror of https://github.com/torvalds/linux.git synced 2025-11-04 10:40:15 +02:00
Code Issues Projects Releases Packages Wiki Activity Actions

objtool: Ditch subcommands

Browse source 
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: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Miroslav Benes <mbenes@suse.cz>
Link: https://lkml.kernel.org/r/5c61ebf805e90aefc5fa62bc63468ffae53b9df6.1650300597.git.jpoimboe@redhat.com
This commit is contained in:
Josh Poimboeuf 2022-04-18 09:50:27 -07:00 committed by Peter Zijlstra
parent 2daf7faba7
commit b51277eb97
10 changed files with 72 additions and 211 deletions
repo.diff.show_diff_stats Download patch file Download diff file Expand all files Collapse all files

2
scripts/Makefile.build
View file

@ -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) \

13
scripts/link-vmlinux.sh
View file

@ -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
}

12
tools/objtool/Build
View file

@ -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

8
tools/objtool/Makefile
View file

@ -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

56
tools/objtool/builtin-check.c
View file

@ -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;

73
tools/objtool/builtin-orc.c
View file

@ -1,73 +0,0 @@
// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Copyright (C) 2017 Josh Poimboeuf <jpoimboe@redhat.com>
*/
/*
* objtool orc:
*
* This command analyzes a .o file and adds .orc_unwind and .orc_unwind_ip
* sections to it, which is used by the in-kernel ORC unwinder.
*
* This command is a superset of "objtool check".
*/
#include <string.h>
#include <objtool/builtin.h>
#include <objtool/objtool.h>
static const char *orc_usage[] = {
"objtool orc generate [<options>] file.o",
"objtool orc dump file.o",
NULL,
};
int cmd_orc(int argc, const char **argv)
{
const char *objname;
argc--; argv++;
if (argc <= 0)
usage_with_options(orc_usage, check_options);
if (!strncmp(argv[0], "gen", 3)) {
struct objtool_file *file;
int ret;
argc = cmd_parse_options(argc, argv, orc_usage);
objname = argv[0];
file = objtool_open_read(objname);
if (!file)
return 1;
ret = check(file);
if (ret)
return ret;
if (list_empty(&file->insn_list))
return 0;
ret = orc_create(file);
if (ret)
return ret;
if (!file->elf->changed)
return 0;
return elf_write(file->elf);
}
if (!strcmp(argv[0], "dump")) {
if (argc != 2)
usage_with_options(orc_usage, check_options);
objname = argv[1];
return orc_dump(objname);
}
usage_with_options(orc_usage, check_options);
return 0;
}

8
tools/objtool/check.c
View file

@ -3949,6 +3949,14 @@ int check(struct objtool_file *file)
warnings += ret;
}
if (opts.orc && !list_empty(&file->insn_list)) {
ret = orc_create(file);
if (ret < 0)
goto out;
warnings += ret;
}
if (opts.stats) {
printf("nr_insns_visited: %ld\n", nr_insns_visited);
printf("nr_cfi: %ld\n", nr_cfi);

5
tools/objtool/include/objtool/builtin.h
View file

@ -11,9 +11,11 @@ extern const struct option check_options[];
struct opts {
/* actions: */
bool dump_orc;
bool ibt;
bool mcount;
bool noinstr;
bool orc;
bool retpoline;
bool sls;
bool uaccess;
@ -34,7 +36,6 @@ extern struct opts opts;
extern int cmd_parse_options(int argc, const char **argv, const char * const usage[]);
extern int cmd_check(int argc, const char **argv);
extern int cmd_orc(int argc, const char **argv);
extern int objtool_run(int argc, const char **argv);
#endif /* _BUILTIN_H */

97
tools/objtool/objtool.c
View file

@ -3,16 +3,6 @@
* Copyright (C) 2015 Josh Poimboeuf <jpoimboe@redhat.com>
*/
/*
* objtool:
*
* The 'check' subcmd 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 <stdio.h>
#include <stdbool.h>
#include <string.h>
@ -26,20 +16,6 @@
#include <objtool/objtool.h>
#include <objtool/warn.h>
struct cmd_struct {
const char *name;
int (*fn)(int, const char **);
const char *help;
};
static const char objtool_usage_string[] =
"objtool COMMAND [ARGS]";
static struct cmd_struct objtool_cmds[] = {
{"check", cmd_check, "Perform stack metadata validation on an object file" },
{"orc", cmd_orc, "Generate in-place ORC unwind tables for an object file" },
};
bool help;
const char *objname;
@ -161,70 +137,6 @@ void objtool_pv_add(struct objtool_file *f, int idx, struct symbol *func)
f->pv_ops[idx].clean = false;
}
static void cmd_usage(void)
{
unsigned int i, longest = 0;
printf("\n usage: %s\n\n", objtool_usage_string);
for (i = 0; i < ARRAY_SIZE(objtool_cmds); i++) {
if (longest < strlen(objtool_cmds[i].name))
longest = strlen(objtool_cmds[i].name);
}
puts(" Commands:");
for (i = 0; i < ARRAY_SIZE(objtool_cmds); i++) {
printf(" %-*s ", longest, objtool_cmds[i].name);
puts(objtool_cmds[i].help);
}
printf("\n");
if (!help)
exit(129);
exit(0);
}
static void handle_options(int *argc, const char ***argv)
{
while (*argc > 0) {
const char *cmd = (*argv)[0];
if (cmd[0] != '-')
break;
if (!strcmp(cmd, "--help") || !strcmp(cmd, "-h")) {
help = true;
break;
} else {
fprintf(stderr, "Unknown option: %s\n", cmd);
cmd_usage();
}
(*argv)++;
(*argc)--;
}
}
static void handle_internal_command(int argc, const char **argv)
{
const char *cmd = argv[0];
unsigned int i, ret;
for (i = 0; i < ARRAY_SIZE(objtool_cmds); i++) {
struct cmd_struct *p = objtool_cmds+i;
if (strcmp(p->name, cmd))
continue;
ret = p->fn(argc, argv);
exit(ret);
}
cmd_usage();
}
int main(int argc, const char **argv)
{
static const char *UNUSED = "OBJTOOL_NOT_IMPLEMENTED";
@ -233,14 +145,7 @@ int main(int argc, const char **argv)
exec_cmd_init("objtool", UNUSED, UNUSED, UNUSED);
pager_init(UNUSED);
argv++;
argc--;
handle_options(&argc, &argv);
if (!argc || help)
cmd_usage();
handle_internal_command(argc, argv);
objtool_run(argc, argv);
return 0;
}

9
tools/objtool/weak.c
View file

@ -15,17 +15,12 @@
return ENOSYS; \
})
int __weak check(struct objtool_file *file)
{
UNSUPPORTED("check subcommand");
}
int __weak orc_dump(const char *_objname)
{
UNSUPPORTED("orc");
UNSUPPORTED("ORC");
}
int __weak orc_create(struct objtool_file *file)
{
UNSUPPORTED("orc");
UNSUPPORTED("ORC");
}