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authorBen Dooks <ben.dooks@codethink.co.uk>2013-07-25 14:38:03 +0100
committerVictor Kamensky <victor.kamensky@linaro.org>2014-03-13 14:48:37 -0700
commit56cbe5efe6f28a7efb459620281717fd7c109e05 (patch)
tree972a35b7ca7530de98d9e86c119bb7b00161f818
parent9884db0b95b316311fc47dcc9456b6d678631e27 (diff)
downloadlinux-linaro-stable-56cbe5efe6f28a7efb459620281717fd7c109e05.tar.gz
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> (cherry picked from commit 63328070eff2f4fd730c86966a0dbc976147c39f) Signed-off-by: Victor Kamensky <victor.kamensky@linaro.org>
-rw-r--r--arch/arm/include/asm/bug.h10
-rw-r--r--arch/arm/kernel/traps.c8
2 files changed, 11 insertions, 7 deletions
diff --git a/arch/arm/include/asm/bug.h b/arch/arm/include/asm/bug.h
index 7af5c6c3653a..b274bde24905 100644
--- a/arch/arm/include/asm/bug.h
+++ b/arch/arm/include/asm/bug.h
@@ -2,6 +2,8 @@
#define _ASMARM_BUG_H
#include <linux/linkage.h>
+#include <linux/types.h>
+#include <asm/opcodes.h>
#ifdef CONFIG_BUG
@@ -12,10 +14,10 @@
*/
#ifdef CONFIG_THUMB2_KERNEL
#define BUG_INSTR_VALUE 0xde02
-#define BUG_INSTR_TYPE ".hword "
+#define BUG_INSTR(__value) __inst_thumb16(__value)
#else
#define BUG_INSTR_VALUE 0xe7f001f2
-#define BUG_INSTR_TYPE ".word "
+#define BUG_INSTR(__value) __inst_arm(__value)
#endif
@@ -33,7 +35,7 @@
#define __BUG(__file, __line, __value) \
do { \
- asm volatile("1:\t" BUG_INSTR_TYPE #__value "\n" \
+ asm volatile("1:\t" BUG_INSTR(__value) "\n" \
".pushsection .rodata.str, \"aMS\", %progbits, 1\n" \
"2:\t.asciz " #__file "\n" \
".popsection\n" \
@@ -48,7 +50,7 @@ do { \
#define __BUG(__file, __line, __value) \
do { \
- asm volatile(BUG_INSTR_TYPE #__value); \
+ asm volatile(BUG_INSTR(__value) "\n"); \
unreachable(); \
} while (0)
#endif /* CONFIG_DEBUG_BUGVERBOSE */
diff --git a/arch/arm/kernel/traps.c b/arch/arm/kernel/traps.c
index 5989b0f317dd..b4fd850c34b2 100644
--- a/arch/arm/kernel/traps.c
+++ b/arch/arm/kernel/traps.c
@@ -348,15 +348,17 @@ void arm_notify_die(const char *str, struct pt_regs *regs,
int is_valid_bugaddr(unsigned long pc)
{
#ifdef CONFIG_THUMB2_KERNEL
- unsigned short bkpt;
+ u16 bkpt;
+ u16 insn = __opcode_to_mem_thumb16(BUG_INSTR_VALUE);
#else
- unsigned long bkpt;
+ u32 bkpt;
+ u32 insn = __opcode_to_mem_arm(BUG_INSTR_VALUE);
#endif
if (probe_kernel_address((unsigned *)pc, bkpt))
return 0;
- return bkpt == BUG_INSTR_VALUE;
+ return bkpt == insn;
}
#endif