linux-stable/tools/objtool/objtool.c
Josh Poimboeuf 627fce1480 objtool: Add ORC unwind table generation
Now that objtool knows the states of all registers on the stack for each
instruction, it's straightforward to generate debuginfo for an unwinder
to use.

Instead of generating DWARF, generate a new format called ORC, which is
more suitable for an in-kernel unwinder.  See
Documentation/x86/orc-unwinder.txt for a more detailed description of
this new debuginfo format and why it's preferable to DWARF.

Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Jiri Slaby <jslaby@suse.cz>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: live-patching@vger.kernel.org
Link: http://lkml.kernel.org/r/c9b9f01ba6c5ed2bdc9bb0957b78167fdbf9632e.1499786555.git.jpoimboe@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-07-18 10:57:43 +02:00

136 lines
3 KiB
C

/*
* Copyright (C) 2015 Josh Poimboeuf <jpoimboe@redhat.com>
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, see <http://www.gnu.org/licenses/>.
*/
/*
* 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>
#include <stdlib.h>
#include <subcmd/exec-cmd.h>
#include <subcmd/pager.h>
#include <linux/kernel.h>
#include "builtin.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;
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");
exit(1);
}
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);
fprintf(stderr, "\n Usage: %s\n",
objtool_usage_string);
exit(1);
}
(*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";
/* libsubcmd init */
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);
return 0;
}