Re: [PATCH] arm64/mm: Poison initmem while freeing with free_reserved_area()

[Steven Price]

On 04/10/2019 05:23, Anshuman Khandual wrote:
> Platform implementation for free_initmem() should poison the memory while
> freeing it up. Hence pass across POISON_FREE_INITMEM while calling into
> free_reserved_area(). The same is being followed in the generic fallback
> for free_initmem() and some other platforms overriding it.
> 
> Cc: Catalin Marinas <catalin.marinas@xxxxxxx>
> Cc: Will Deacon <will@xxxxxxxxxx>
> Cc: Mark Rutland <mark.rutland@xxxxxxx>
> Cc: linux-kernel@xxxxxxxxxxxxxxx
> Signed-off-by: Anshuman Khandual <anshuman.khandual@xxxxxxx>

Is there a good reason you haven't made a similar change to
free_initrd_mem() - the same logic seems to apply. However this change
looks fine to me.

Reviewed-by: Steven Price <steven.price@xxxxxxx>

> ---
>  arch/arm64/mm/init.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/arch/arm64/mm/init.c b/arch/arm64/mm/init.c
> index 45c00a54909c..ea7d38011e83 100644
> --- a/arch/arm64/mm/init.c
> +++ b/arch/arm64/mm/init.c
> @@ -571,7 +571,7 @@ void free_initmem(void)
>  {
>  	free_reserved_area(lm_alias(__init_begin),
>  			   lm_alias(__init_end),
> -			   0, "unused kernel");
> +			   POISON_FREE_INITMEM, "unused kernel");
>  	/*
>  	 * Unmap the __init region but leave the VM area in place. This
>  	 * prevents the region from being reused for kernel modules, which
>