diff mbox

[11/19] ARM: alignment: correctly decode instructions in BE8 mode.

Message ID 1377690359-25397-12-git-send-email-ben.dooks@codethink.co.uk (mailing list archive)
State New, archived
Headers show

Commit Message

Ben Dooks Aug. 28, 2013, 11:45 a.m. UTC
If we are in BE8 mode, we must deal with the instruction stream being
in LE order when data is being loaded in BE order. Ensure the data is
swapped before processing to avoid thre following:

Change to using <asm/opcodes.h> to provide the necessary conversion
functions to change the byte ordering.

Alignment trap: not handling instruction 030091e8 at [<80333e8c>]
Unhandled fault: alignment exception (0x001) at 0xbfa09567

Signed-off-by: Ben Dooks <ben.dooks@codethink.co.uk>
---
 arch/arm/mm/alignment.c |    9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

Comments

Sergei Shtylyov Aug. 28, 2013, 7:40 p.m. UTC | #1
Hello.

On 08/28/2013 03:45 PM, Ben Dooks wrote:

> If we are in BE8 mode, we must deal with the instruction stream being
> in LE order when data is being loaded in BE order. Ensure the data is
> swapped before processing to avoid thre following:

> Change to using <asm/opcodes.h> to provide the necessary conversion
> functions to change the byte ordering.

> Alignment trap: not handling instruction 030091e8 at [<80333e8c>]
> Unhandled fault: alignment exception (0x001) at 0xbfa09567

    I guess the above 2 paragraphs are swapped.

> Signed-off-by: Ben Dooks <ben.dooks@codethink.co.uk>

WBR, Sergei
Ben Dooks Aug. 30, 2013, 6:47 p.m. UTC | #2
On 28/08/13 20:40, Sergei Shtylyov wrote:
> Hello.
>
> On 08/28/2013 03:45 PM, Ben Dooks wrote:
>
>> If we are in BE8 mode, we must deal with the instruction stream being
>> in LE order when data is being loaded in BE order. Ensure the data is
>> swapped before processing to avoid thre following:
>
>> Change to using <asm/opcodes.h> to provide the necessary conversion
>> functions to change the byte ordering.
>
>> Alignment trap: not handling instruction 030091e8 at [<80333e8c>]
>> Unhandled fault: alignment exception (0x001) at 0xbfa09567
>
> I guess the above 2 paragraphs are swapped.
>
>> Signed-off-by: Ben Dooks <ben.dooks@codethink.co.uk>
>
> WBR, Sergei

thanks, I also forgot to put a sentence to say that these where
kernel messages.
diff mbox

Patch

diff --git a/arch/arm/mm/alignment.c b/arch/arm/mm/alignment.c
index 6f4585b..9240364 100644
--- a/arch/arm/mm/alignment.c
+++ b/arch/arm/mm/alignment.c
@@ -25,6 +25,7 @@ 
 #include <asm/cp15.h>
 #include <asm/system_info.h>
 #include <asm/unaligned.h>
+#include <asm/opcodes.h>
 
 #include "fault.h"
 
@@ -762,21 +763,25 @@  do_alignment(unsigned long addr, unsigned int fsr, struct pt_regs *regs)
 	if (thumb_mode(regs)) {
 		u16 *ptr = (u16 *)(instrptr & ~1);
 		fault = probe_kernel_address(ptr, tinstr);
+		tinstr = __mem_to_opcode_thumb16(tinstr);
 		if (!fault) {
 			if (cpu_architecture() >= CPU_ARCH_ARMv7 &&
 			    IS_T32(tinstr)) {
 				/* Thumb-2 32-bit */
 				u16 tinst2 = 0;
 				fault = probe_kernel_address(ptr + 1, tinst2);
-				instr = (tinstr << 16) | tinst2;
+				tinst2 = __mem_to_opcode_thumb16(tinst2);
+				instr = __opcode_thumb32_compose(tinstr, tinst2);
 				thumb2_32b = 1;
 			} else {
 				isize = 2;
 				instr = thumb2arm(tinstr);
 			}
 		}
-	} else
+	} else {
 		fault = probe_kernel_address(instrptr, instr);
+		instr = __mem_to_opcode_arm(instr);
+	}
 
 	if (fault) {
 		type = TYPE_FAULT;