From mboxrd@z Thu Jan  1 00:00:00 1970
From: will.deacon@arm.com (Will Deacon)
Date: Wed, 24 Jul 2013 17:20:37 +0100
Subject: [PATCH 12/14] ARM: traps: use <asm/opcodes.h> to get correct
 instruction order
In-Reply-To: <1374661682-9349-13-git-send-email-ben.dooks@codethink.co.uk>
References: <1374661682-9349-1-git-send-email-ben.dooks@codethink.co.uk>
 <1374661682-9349-13-git-send-email-ben.dooks@codethink.co.uk>
Message-ID: <20130724162036.GS11072@mudshark.cambridge.arm.com>
To: linux-arm-kernel@lists.infradead.org
List-Id: linux-arm-kernel.lists.infradead.org

On Wed, Jul 24, 2013 at 11:28:00AM +0100, Ben Dooks wrote:
> The trap handler needs to take into account the endian configuration of
> the system when loading instructions. Use <asm/opcodes.h> to provide the
> necessary conversion functions.
> 
> Signed-off-by: Ben Dooks <ben.dooks@codethink.co.uk>
> ---
>  arch/arm/kernel/traps.c |   10 ++++++----
>  1 file changed, 6 insertions(+), 4 deletions(-)
> 
> diff --git a/arch/arm/kernel/traps.c b/arch/arm/kernel/traps.c
> index 18b32e8..c300e51 100644
> --- a/arch/arm/kernel/traps.c
> +++ b/arch/arm/kernel/traps.c
> @@ -34,6 +34,7 @@
>  #include <asm/unwind.h>
>  #include <asm/tls.h>
>  #include <asm/system_misc.h>
> +#include <asm/opcodes.h>
>  
>  #include "signal.h"
>  
> @@ -404,23 +405,24 @@ asmlinkage void __exception do_undefinstr(struct pt_regs *regs)
>  	if (processor_mode(regs) == SVC_MODE) {
>  #ifdef CONFIG_THUMB2_KERNEL
>  		if (thumb_mode(regs)) {
> -			instr = ((u16 *)pc)[0];
> +			instr = __mem_to_opcode_thumb16(((u16 *)pc)[0]);
>  			if (is_wide_instruction(instr)) {
>  				instr <<= 16;
> -				instr |= ((u16 *)pc)[1];
> +				instr |= __mem_to_opcode_thumb16(((u16 *)pc)[1]);
>  			}
>  		} else
>  #endif
> -			instr = *(u32 *) pc;
> +			instr = __mem_to_opcode_arm(*(u32 *) pc);
>  	} else if (thumb_mode(regs)) {
>  		if (get_user(instr, (u16 __user *)pc))
>  			goto die_sig;
> +		instr = __mem_to_opcode_thumb16(instr);
>  		if (is_wide_instruction(instr)) {
>  			unsigned int instr2;
>  			if (get_user(instr2, (u16 __user *)pc+1))
>  				goto die_sig;
>  			instr <<= 16;
> -			instr |= instr2;
> +			instr |= __mem_to_opcode_thumb16(instr2);
>  		}
>  	} else if (get_user(instr, (u32 __user *)pc)) {
>  		goto die_sig;

Maybe it's also worth updating dump_instr, so that we don't confuse people
by printing the faulting instruction in the wrong endianness.

Will