[PATCH -next] arm32: enable HAVE_LD_DEAD_CODE_DATA_ELIMINATION

[liuyuntao (F)]

On 2024/2/22 17:52, Arnd Bergmann wrote:
> On Wed, Feb 21, 2024, at 16:51, Arnd Bergmann wrote:
>> I have given your patch some build testing with random
>> configurations in my build setup and it seems to work
>> fine with gcc/binutils, but unfortunately I came across
>> a link failure using clang/lld:
> 
> I ran into another bug now, this time with CONFIG_XIP_KERNEL=y:
> 
> no __ex_table in file: vmlinux
> Failed to sort kernel tables
> make[4]: *** [scripts/Makefile.vmlinux:37: vmlinux] Error 1
> 
> Essentially you have to modify arch/arm/kernel/vmlinux-xip.lds.S
> the same way as vmlinux.lds.S:
>
Thanks a lot. I didn't consider this situation. I will take your advice. 
Thanks again.

> --- a/arch/arm/kernel/vmlinux-xip.lds.S
> +++ b/arch/arm/kernel/vmlinux-xip.lds.S
> @@ -63,7 +63,7 @@ SECTIONS
>          . = ALIGN(4);
>          __ex_table : AT(ADDR(__ex_table) - LOAD_OFFSET) {
>                  __start___ex_table = .;
> -               ARM_MMU_KEEP(*(__ex_table))
> +               ARM_MMU_KEEP(KEEP(*(__ex_table)))
>                  __stop___ex_table = .;
>          }
>   
> @@ -83,7 +83,7 @@ SECTIONS
>          }
>          .init.arch.info : {
>                  __arch_info_begin = .;
> -               *(.arch.info.init)
> +               KEEP(*(.arch.info.init))
>                  __arch_info_end = .;
>          }
>          .init.tagtable : {
> 
> 
> The pv_table is not needed for XIP_KERNEL=y because that
> requires not patching the kernel.
> 
>      Arnd