linux-stable/arch/arm/include/asm/bug.h
Ben Dooks 63328070ef ARM: Correct BUG() assembly to ensure it is endian-agnostic
Currently BUG() uses .word or .hword to create the necessary illegal
instructions. However if we are building BE8 then these get swapped
by the linker into different illegal instructions in the text. This
means that the BUG() macro does not get trapped properly.

Change to using <asm/opcodes.h> to provide the necessary ARM instruction
building as we cannot rely on gcc/gas having the `.inst` instructions
which where added to try and resolve this issue (reported by Dave Martin
<Dave.Martin@arm.com>).

Signed-off-by: Ben Dooks <ben.dooks@codethink.co.uk>
Reviewed-by: Dave Martin <Dave.Martin@arm.com>
2013-10-19 20:46:35 +01:00

92 lines
2.5 KiB
C

#ifndef _ASMARM_BUG_H
#define _ASMARM_BUG_H
#include <linux/linkage.h>
#include <linux/types.h>
#include <asm/opcodes.h>
#ifdef CONFIG_BUG
/*
* Use a suitable undefined instruction to use for ARM/Thumb2 bug handling.
* We need to be careful not to conflict with those used by other modules and
* the register_undef_hook() system.
*/
#ifdef CONFIG_THUMB2_KERNEL
#define BUG_INSTR_VALUE 0xde02
#define BUG_INSTR(__value) __inst_thumb16(__value)
#else
#define BUG_INSTR_VALUE 0xe7f001f2
#define BUG_INSTR(__value) __inst_arm(__value)
#endif
#define BUG() _BUG(__FILE__, __LINE__, BUG_INSTR_VALUE)
#define _BUG(file, line, value) __BUG(file, line, value)
#ifdef CONFIG_DEBUG_BUGVERBOSE
/*
* The extra indirection is to ensure that the __FILE__ string comes through
* OK. Many version of gcc do not support the asm %c parameter which would be
* preferable to this unpleasantness. We use mergeable string sections to
* avoid multiple copies of the string appearing in the kernel image.
*/
#define __BUG(__file, __line, __value) \
do { \
asm volatile("1:\t" BUG_INSTR(__value) "\n" \
".pushsection .rodata.str, \"aMS\", %progbits, 1\n" \
"2:\t.asciz " #__file "\n" \
".popsection\n" \
".pushsection __bug_table,\"a\"\n" \
"3:\t.word 1b, 2b\n" \
"\t.hword " #__line ", 0\n" \
".popsection"); \
unreachable(); \
} while (0)
#else /* not CONFIG_DEBUG_BUGVERBOSE */
#define __BUG(__file, __line, __value) \
do { \
asm volatile(BUG_INSTR(__value) "\n"); \
unreachable(); \
} while (0)
#endif /* CONFIG_DEBUG_BUGVERBOSE */
#define HAVE_ARCH_BUG
#endif /* CONFIG_BUG */
#include <asm-generic/bug.h>
struct pt_regs;
void die(const char *msg, struct pt_regs *regs, int err);
struct siginfo;
void arm_notify_die(const char *str, struct pt_regs *regs, struct siginfo *info,
unsigned long err, unsigned long trap);
#ifdef CONFIG_ARM_LPAE
#define FAULT_CODE_ALIGNMENT 33
#define FAULT_CODE_DEBUG 34
#else
#define FAULT_CODE_ALIGNMENT 1
#define FAULT_CODE_DEBUG 2
#endif
void hook_fault_code(int nr, int (*fn)(unsigned long, unsigned int,
struct pt_regs *),
int sig, int code, const char *name);
void hook_ifault_code(int nr, int (*fn)(unsigned long, unsigned int,
struct pt_regs *),
int sig, int code, const char *name);
extern asmlinkage void c_backtrace(unsigned long fp, int pmode);
struct mm_struct;
extern void show_pte(struct mm_struct *mm, unsigned long addr);
extern void __show_regs(struct pt_regs *);
#endif