Re: [PATCH] arm64: extable: sort the exception table at build time

[Sam Ravnborg <sam@ravnborg.org>]

On Fri, May 17, 2013 at 05:43:41PM +0100, Will Deacon wrote:
> As is done for other architectures, sort the exception table at
> build-time rather than during boot.
> 
> Since sortextable appears to be a standalone C program relying on the
> host elf.h to provide EM_AARCH64, I've had to add a conditional check in
> order to allow cross-compilation on machines that aren't running a
> bleeding-edge libc-dev.
> 
> Signed-off-by: Will Deacon <will.deacon@arm.com>
> ---
>  arch/arm64/Kconfig              |  1 +
>  arch/arm64/kernel/vmlinux.lds.S | 15 +++++++--------
>  scripts/sortextable.c           |  5 +++++
>  3 files changed, 13 insertions(+), 8 deletions(-)
> 
> diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
> index 48347dc..fb8fd90 100644
> --- a/arch/arm64/Kconfig
> +++ b/arch/arm64/Kconfig
> @@ -7,6 +7,7 @@ config ARM64
>  	select ARM_AMBA
>  	select ARM_ARCH_TIMER
>  	select ARM_GIC
> +	select BUILDTIME_EXTABLE_SORT
>  	select CLONE_BACKWARDS
>  	select COMMON_CLK
>  	select GENERIC_CLOCKEVENTS
> diff --git a/arch/arm64/kernel/vmlinux.lds.S b/arch/arm64/kernel/vmlinux.lds.S
> index 3fae2be..3d527726 100644
> --- a/arch/arm64/kernel/vmlinux.lds.S
> +++ b/arch/arm64/kernel/vmlinux.lds.S
> @@ -57,6 +57,13 @@ SECTIONS
>  
>  	RO_DATA(PAGE_SIZE)
>  
> +	. = ALIGN(8);
> +	__ex_table : AT(ADDR(__ex_table) - LOAD_OFFSET) {
> +		__start___ex_table = .;
> +		*(__ex_table)
> +		__stop___ex_table = .;
> +	}

Here you could use:
     EXCEPTION_TABLE(align)

(From include/asm-generic/vmlinux.lds.h)

	Sam