mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-10-31 08:28:13 +00:00
867ac9d737
Objtool tries to silence 'unreachable instruction' warnings when it
detects gcov is enabled, because gcov produces a lot of unreachable
instructions and they don't really matter.
However, the 0-day bot is still reporting some unreachable instruction
warnings with CONFIG_GCOV_KERNEL=y on GCC 4.6.4.
As it turns out, objtool's gcov detection doesn't work with older
versions of GCC because they don't create a bunch of symbols with the
'gcov.' prefix like newer versions of GCC do.
Move the gcov check out of objtool and instead just create a new
'--no-unreachable' flag which can be passed in by the kernel Makefile
when CONFIG_GCOV_KERNEL is defined.
Also rename the 'nofp' variable to 'no_fp' for consistency with the new
'no_unreachable' variable.
Reported-by: kbuild test robot <fengguang.wu@intel.com>
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Fixes: 9cfffb1168 ("objtool: Skip all "unreachable instruction" warnings for gcov kernels")
Link: http://lkml.kernel.org/r/c243dc78eb2ffdabb6e927844dea39b6033cd395.1500939244.git.jpoimboe@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
57 lines
1.7 KiB
C
57 lines
1.7 KiB
C
/*
|
|
* Copyright (C) 2015-2017 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 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 "builtin.h"
|
|
#include "check.h"
|
|
|
|
bool no_fp, no_unreachable;
|
|
|
|
static const char * const check_usage[] = {
|
|
"objtool check [<options>] file.o",
|
|
NULL,
|
|
};
|
|
|
|
const struct option check_options[] = {
|
|
OPT_BOOLEAN('f', "no-fp", &no_fp, "Skip frame pointer validation"),
|
|
OPT_BOOLEAN('u', "no-unreachable", &no_unreachable, "Skip 'unreachable instruction' warnings"),
|
|
OPT_END(),
|
|
};
|
|
|
|
int cmd_check(int argc, const char **argv)
|
|
{
|
|
const char *objname;
|
|
|
|
argc = parse_options(argc, argv, check_options, check_usage, 0);
|
|
|
|
if (argc != 1)
|
|
usage_with_options(check_usage, check_options);
|
|
|
|
objname = argv[0];
|
|
|
|
return check(objname, no_fp, no_unreachable, false);
|
|
}
|