Re: [PATCH 01/42] x86, kasl: Remove not needed parameter for choose_kernel_location

From: Kees Cook
Date: Tue Jul 07 2015 - 16:58:09 EST


The subject has a typo "kasl" should be "kaslr".

On Tue, Jul 7, 2015 at 1:19 PM, Yinghai Lu <yinghai@xxxxxxxxxx> wrote:
> real_mode is global variable, so we do not need to pass it around.
>
> Signed-off-by: Yinghai Lu <yinghai@xxxxxxxxxx>

Other than that, yeah, there's no good reason to pass that around.

Acked-by: Kees Cook <keescook@xxxxxxxxxxxx>

-Kees

> ---
> arch/x86/boot/compressed/aslr.c | 5 ++---
> arch/x86/boot/compressed/misc.c | 2 +-
> arch/x86/boot/compressed/misc.h | 6 ++----
> 3 files changed, 5 insertions(+), 8 deletions(-)
>
> diff --git a/arch/x86/boot/compressed/aslr.c b/arch/x86/boot/compressed/aslr.c
> index d7b1f65..71520c4 100644
> --- a/arch/x86/boot/compressed/aslr.c
> +++ b/arch/x86/boot/compressed/aslr.c
> @@ -295,8 +295,7 @@ static unsigned long find_random_addr(unsigned long minimum,
> return slots_fetch_random();
> }
>
> -unsigned char *choose_kernel_location(struct boot_params *boot_params,
> - unsigned char *input,
> +unsigned char *choose_kernel_location(unsigned char *input,
> unsigned long input_size,
> unsigned char *output,
> unsigned long output_size)
> @@ -316,7 +315,7 @@ unsigned char *choose_kernel_location(struct boot_params *boot_params,
> }
> #endif
>
> - boot_params->hdr.loadflags |= KASLR_FLAG;
> + real_mode->hdr.loadflags |= KASLR_FLAG;
>
> /* Record the various known unsafe memory ranges. */
> mem_avoid_init((unsigned long)input, input_size,
> diff --git a/arch/x86/boot/compressed/misc.c b/arch/x86/boot/compressed/misc.c
> index a107b93..ebf72ce 100644
> --- a/arch/x86/boot/compressed/misc.c
> +++ b/arch/x86/boot/compressed/misc.c
> @@ -404,7 +404,7 @@ asmlinkage __visible void *decompress_kernel(void *rmode, memptr heap,
> * the entire decompressed kernel plus relocation table, or the
> * entire decompressed kernel plus .bss and .brk sections.
> */
> - output = choose_kernel_location(real_mode, input_data, input_len, output,
> + output = choose_kernel_location(input_data, input_len, output,
> output_len > run_size ? output_len
> : run_size);
>
> diff --git a/arch/x86/boot/compressed/misc.h b/arch/x86/boot/compressed/misc.h
> index 805d25c..8c96cc5 100644
> --- a/arch/x86/boot/compressed/misc.h
> +++ b/arch/x86/boot/compressed/misc.h
> @@ -56,8 +56,7 @@ int cmdline_find_option_bool(const char *option);
>
> #if CONFIG_RANDOMIZE_BASE
> /* aslr.c */
> -unsigned char *choose_kernel_location(struct boot_params *boot_params,
> - unsigned char *input,
> +unsigned char *choose_kernel_location(unsigned char *input,
> unsigned long input_size,
> unsigned char *output,
> unsigned long output_size);
> @@ -65,8 +64,7 @@ unsigned char *choose_kernel_location(struct boot_params *boot_params,
> bool has_cpuflag(int flag);
> #else
> static inline
> -unsigned char *choose_kernel_location(struct boot_params *boot_params,
> - unsigned char *input,
> +unsigned char *choose_kernel_location(unsigned char *input,
> unsigned long input_size,
> unsigned char *output,
> unsigned long output_size)
> --
> 1.8.4.5
>



--
Kees Cook
Chrome OS Security
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