From: Ard Biesheuvel Date: Wed, 15 Dec 2021 08:31:36 +0000 (+0100) Subject: ARM: 9169/1: entry: fix Thumb2 bug in iWMMXt exception handling X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=8536a5ef886005bc443c2da9b842d69fd3d7647f;p=linux.git ARM: 9169/1: entry: fix Thumb2 bug in iWMMXt exception handling The Thumb2 version of the FP exception handling entry code treats the register holding the CP number (R8) differently, resulting in the iWMMXT CP number check to be incorrect. Fix this by unifying the ARM and Thumb2 code paths, and switch the order of the additions of the TI_USED_CP offset and the shifted CP index. Cc: Fixes: b86040a59feb ("Thumb-2: Implementation of the unified start-up and exceptions code") Signed-off-by: Ard Biesheuvel Signed-off-by: Russell King (Oracle) --- diff --git a/arch/arm/kernel/entry-armv.S b/arch/arm/kernel/entry-armv.S index deff286eb5ea0..5cd057859fe90 100644 --- a/arch/arm/kernel/entry-armv.S +++ b/arch/arm/kernel/entry-armv.S @@ -596,11 +596,9 @@ call_fpe: tstne r0, #0x04000000 @ bit 26 set on both ARM and Thumb-2 reteq lr and r8, r0, #0x00000f00 @ mask out CP number - THUMB( lsr r8, r8, #8 ) mov r7, #1 - add r6, r10, #TI_USED_CP - ARM( strb r7, [r6, r8, lsr #8] ) @ set appropriate used_cp[] - THUMB( strb r7, [r6, r8] ) @ set appropriate used_cp[] + add r6, r10, r8, lsr #8 @ add used_cp[] array offset first + strb r7, [r6, #TI_USED_CP] @ set appropriate used_cp[] #ifdef CONFIG_IWMMXT @ Test if we need to give access to iWMMXt coprocessors ldr r5, [r10, #TI_FLAGS] @@ -609,7 +607,7 @@ call_fpe: bcs iwmmxt_task_enable #endif ARM( add pc, pc, r8, lsr #6 ) - THUMB( lsl r8, r8, #2 ) + THUMB( lsr r8, r8, #6 ) THUMB( add pc, r8 ) nop