linux/arch/arm64/include/asm/bug.h
Peter Zijlstra 19d436268d debug: Add _ONCE() logic to report_bug()
Josh suggested moving the _ONCE logic inside the trap handler, using a
bit in the bug_entry::flags field, avoiding the need for the extra
variable.

Sadly this only works for WARN_ON_ONCE(), since the others have
printk() statements prior to triggering the trap.

Still, this saves a fair amount of text and some data:

  text         data       filename
  10682460     4530992    defconfig-build/vmlinux.orig
  10665111     4530096    defconfig-build/vmlinux.patched

Suggested-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
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: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-03-30 09:37:20 +02:00

65 lines
1.7 KiB
C

/*
* Copyright (C) 2015 ARM Limited
* Author: Dave Martin <Dave.Martin@arm.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* 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/>.
*/
#ifndef _ARCH_ARM64_ASM_BUG_H
#define _ARCH_ARM64_ASM_BUG_H
#include <asm/brk-imm.h>
#ifdef CONFIG_GENERIC_BUG
#define HAVE_ARCH_BUG
#ifdef CONFIG_DEBUG_BUGVERBOSE
#define _BUGVERBOSE_LOCATION(file, line) __BUGVERBOSE_LOCATION(file, line)
#define __BUGVERBOSE_LOCATION(file, line) \
".pushsection .rodata.str,\"aMS\",@progbits,1\n" \
"2: .string \"" file "\"\n\t" \
".popsection\n\t" \
\
".long 2b - 0b\n\t" \
".short " #line "\n\t"
#else
#define _BUGVERBOSE_LOCATION(file, line)
#endif
#define _BUG_FLAGS(flags) __BUG_FLAGS(flags)
#define __BUG_FLAGS(flags) asm volatile ( \
".pushsection __bug_table,\"a\"\n\t" \
".align 2\n\t" \
"0: .long 1f - 0b\n\t" \
_BUGVERBOSE_LOCATION(__FILE__, __LINE__) \
".short " #flags "\n\t" \
".popsection\n" \
\
"1: brk %[imm]" \
:: [imm] "i" (BUG_BRK_IMM) \
)
#define BUG() do { \
_BUG_FLAGS(0); \
unreachable(); \
} while (0)
#define __WARN_FLAGS(flags) _BUG_FLAGS(BUGFLAG_WARNING|(flags))
#endif /* ! CONFIG_GENERIC_BUG */
#include <asm-generic/bug.h>
#endif /* ! _ARCH_ARM64_ASM_BUG_H */