Commit db44e9c5 authored by Mark Rutland's avatar Mark Rutland
Browse files

arm64: Add ASM_BUG() 



Currently. we can only use BUG() from C code, though there are
situations where we would like an equivalent mechanism in assembly code.

This patch refactors our BUG() definition such that it can be used in
either C or assembly, in the form of a new ASM_BUG().

The refactoring requires the removal of escape sequences, such as '\n'
and '\t', but these aren't strictly necessary as we can use ';' to
terminate assembler statements.

The low-level assembly is factored out into <asm/asm-bug.h>, with
<asm/bug.h> retained as the C wrapper.

Signed-off-by: default avatarMark Rutland <mark.rutland@arm.com>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Dave Martin <dave.martin@arm.com>
Cc: James Morse <james.morse@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
parent 16f73eb0

arch/arm64/include/asm/asm-bug.h

0 → 100644
+54 −0
Original line number Original line Diff line number Diff line 
#ifndef __ASM_ASM_BUG_H

/*

 * Copyright (C) 2017  ARM Limited

 *

 * 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/>.

 */

#define __ASM_ASM_BUG_H



#include <asm/brk-imm.h>



#ifdef CONFIG_DEBUG_BUGVERBOSE

#define _BUGVERBOSE_LOCATION(file, line) __BUGVERBOSE_LOCATION(file, line)

#define __BUGVERBOSE_LOCATION(file, line)			\

		.pushsection .rodata.str,"aMS",@progbits,1;	\

	2:	.string file;					\

		.popsection;					\

								\

		.long 2b - 0b;					\

		.short line;

#else

#define _BUGVERBOSE_LOCATION(file, line)

#endif



#ifdef CONFIG_GENERIC_BUG



#define __BUG_ENTRY(flags) 				\

		.pushsection __bug_table,"aw";		\

		.align 2;				\

	0:	.long 1f - 0b;				\

_BUGVERBOSE_LOCATION(__FILE__, __LINE__)		\

		.short flags; 				\

		.popsection;				\

	1:

#else

#define __BUG_ENTRY(flags)

#endif



#define ASM_BUG_FLAGS(flags)				\

	__BUG_ENTRY(flags)				\

	brk	BUG_BRK_IMM



#define ASM_BUG()	ASM_BUG_FLAGS(0)



#endif /* __ASM_ASM_BUG_H */

arch/arm64/include/asm/bug.h

+3 −32
Original line number Original line Diff line number Diff line
@@ -18,41 +18,12 @@ 
#ifndef _ARCH_ARM64_ASM_BUG_H

#ifndef _ARCH_ARM64_ASM_BUG_H

#define _ARCH_ARM64_ASM_BUG_H

#define _ARCH_ARM64_ASM_BUG_H





#include <asm/brk-imm.h>

#include <linux/stringify.h>





#ifdef CONFIG_DEBUG_BUGVERBOSE

#include <asm/asm-bug.h>

#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



#ifdef CONFIG_GENERIC_BUG



#define __BUG_ENTRY(flags) 				\

		".pushsection __bug_table,\"aw\"\n\t"	\

		".align 2\n\t"				\

	"0:	.long 1f - 0b\n\t"			\

_BUGVERBOSE_LOCATION(__FILE__, __LINE__)		\

		".short " #flags "\n\t"			\

		".popsection\n"				\

	"1:	"

#else

#define __BUG_ENTRY(flags) ""

#endif





#define __BUG_FLAGS(flags)				\

#define __BUG_FLAGS(flags)				\

	asm volatile (					\

	asm volatile (__stringify(ASM_BUG_FLAGS(flags)));

		__BUG_ENTRY(flags)			\

		"brk %[imm]" :: [imm] "i" (BUG_BRK_IMM)	\

	);







#define BUG() do {					\

#define BUG() do {					\

	__BUG_FLAGS(0);					\

	__BUG_FLAGS(0);					\

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