Re: [PATCH] MIPS: KASLR: Drop relocatable fixup from reservation_init

[Serge Semin <fancer.lancer@gmail.com>]

On Mon, Jan 22, 2018 at 04:33:31PM +0000, Matt Redfearn <matt.redfearn@mips.com> wrote:
> A recent change ("MIPS: memblock: Discard bootmem initialization")
> removed the reservation of all memory below the kernel's _end symbol in
> bootmem. This makes the call to free_bootmem unnecessary, since the
> memory region is no longer marked reserved.
> 
> Additionally, ("MIPS: memblock: Print out kernel virtual mem
> layout") added a display of the kernel's virtual memory layout, so
> printing the relocation information at this point is redundant.
> 
> Remove this section of code.
> 
> Signed-off-by: Matt Redfearn <matt.redfearn@mips.com>
> 
> ---
> 
> This patch (or a derivative of it) tidies up some of the bootmem init code
> when CONFIG_RELOCATABLE is active during the switch to memblock - please
> can you include in the series?
> 

Agree. I'll merge it with the patch "[PATCH 04/14] MIPS: memblock: Discard
bootmem initialization" of the series in the next version of the patchset.

Regards,
-Sergey

> Thanks,
> Matt
> ---
>  arch/mips/kernel/setup.c | 23 -----------------------
>  1 file changed, 23 deletions(-)
> 
> diff --git a/arch/mips/kernel/setup.c b/arch/mips/kernel/setup.c
> index 99bfaa6b9279..a0eac8160750 100644
> --- a/arch/mips/kernel/setup.c
> +++ b/arch/mips/kernel/setup.c
> @@ -536,29 +536,6 @@ static void __init reservation_init(void)
>  		}
>  	}
>  
> -#ifdef CONFIG_RELOCATABLE
> -	/*
> -	 * The kernel reserves all memory below its _end symbol as bootmem,
> -	 * but the kernel may now be at a much higher address. The memory
> -	 * between the original and new locations may be returned to the system.
> -	 */
> -	if (__pa_symbol(_text) > __pa_symbol(VMLINUX_LOAD_ADDRESS)) {
> -		unsigned long offset;
> -		extern void show_kernel_relocation(const char *level);
> -
> -		offset = __pa_symbol(_text) - __pa_symbol(VMLINUX_LOAD_ADDRESS);
> -		free_bootmem(__pa_symbol(VMLINUX_LOAD_ADDRESS), offset);
> -
> -#if defined(CONFIG_DEBUG_KERNEL) && defined(CONFIG_DEBUG_INFO)
> -		/*
> -		 * This information is necessary when debugging the kernel
> -		 * But is a security vulnerability otherwise!
> -		 */
> -		show_kernel_relocation(KERN_INFO);
> -#endif
> -	}
> -#endif
> -
>  	/*
>  	 * Reserve initrd memory if needed.
>  	 */
> -- 
> 2.7.4
>