From 946a105e16651c35e9cc670bff23812761f1ad35 Mon Sep 17 00:00:00 2001 From: Dave Martin Date: Tue, 14 Jun 2011 14:20:44 +0100 Subject: ARM: 6961/1: zImage: Add build-time check for correctly-sized proc_type entries It is easy to mis-maintain the proc_types table such that the entries become wrongly-sized and misaligned when the kernel is built in Thumb-2. This patch adds an assembly-time check which will turn most common size/alignment mistakes in this table into build failures, to avoid having to debug the boot-time kernel hang which would happen if the resulting kernel were actually booted. Signed-off-by: Dave Martin Acked-by: Nicolas Pitre Signed-off-by: Russell King diff --git a/arch/arm/boot/compressed/head.S b/arch/arm/boot/compressed/head.S index 942fad9..940b201 100644 --- a/arch/arm/boot/compressed/head.S +++ b/arch/arm/boot/compressed/head.S @@ -597,6 +597,8 @@ __common_mmu_cache_on: sub pc, lr, r0, lsr #32 @ properly flush pipeline #endif +#define PROC_ENTRY_SIZE (4*5) + /* * Here follow the relocatable cache support functions for the * various processors. This is a generic hook for locating an @@ -624,7 +626,7 @@ call_cache_fn: adr r12, proc_types ARM( addeq pc, r12, r3 ) @ call cache function THUMB( addeq r12, r3 ) THUMB( moveq pc, r12 ) @ call cache function - add r12, r12, #4*5 + add r12, r12, #PROC_ENTRY_SIZE b 1b /* @@ -794,6 +796,16 @@ proc_types: .size proc_types, . - proc_types + /* + * If you get a "non-constant expression in ".if" statement" + * error from the assembler on this line, check that you have + * not accidentally written a "b" instruction where you should + * have written W(b). + */ + .if (. - proc_types) % PROC_ENTRY_SIZE != 0 + .error "The size of one or more proc_types entries is wrong." + .endif + /* * Turn off the Cache and MMU. ARMv3 does not support * reading the control register, but ARMv4 does. -- cgit v0.10.2