[PATCH] ARM: zImage: Add build-time check for correctly-sized proc_type entries
nicolas.pitre at linaro.org
Sun Jun 12 01:09:49 EDT 2011
On Thu, 9 Jun 2011, Dave Martin wrote:
> 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 <dave.martin at linaro.org>
Acked-by: Nicolas Pitre <nicolas.pitre at linaro.org>
> KernelVersion: v3.0-rc2
> arch/arm/boot/compressed/head.S | 14 +++++++++++++-
> 1 files changed, 13 insertions(+), 1 deletions(-)
> diff --git a/arch/arm/boot/compressed/head.S b/arch/arm/boot/compressed/head.S
> index f9da419..0aae741 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
> +#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.
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