[PATCH 01/99] ZBOOT: fix stack protector in compressed boot phase

[Huacai Chen]

This is a single patch, please ignore 1/99 in the title...

Huacai

On Thu, Mar 1, 2018 at 10:53 AM, Huacai Chen <chenhc at lemote.com> wrote:
> Call __stack_chk_guard_setup() in decompress_kernel() is too late that
> stack checking always fails for decompress_kernel() itself. So remove
> __stack_chk_guard_setup() and initialize __stack_chk_guard at where we
> define it.
>
> Original code comes from ARM but also used for MIPS and SH, so fix them
> together.
>
> Cc: stable at vger.kernel.org
> Signed-off-by: Huacai Chen <chenhc at lemote.com>
> ---
>  arch/arm/boot/compressed/misc.c        | 9 +--------
>  arch/mips/boot/compressed/decompress.c | 9 +--------
>  arch/sh/boot/compressed/misc.c         | 9 +--------
>  3 files changed, 3 insertions(+), 24 deletions(-)
>
> diff --git a/arch/arm/boot/compressed/misc.c b/arch/arm/boot/compressed/misc.c
> index 16a8a80..43aca75 100644
> --- a/arch/arm/boot/compressed/misc.c
> +++ b/arch/arm/boot/compressed/misc.c
> @@ -128,12 +128,7 @@ asmlinkage void __div0(void)
>         error("Attempting division by 0!");
>  }
>
> -unsigned long __stack_chk_guard;
> -
> -void __stack_chk_guard_setup(void)
> -{
> -       __stack_chk_guard = 0x000a0dff;
> -}
> +unsigned long __stack_chk_guard = 0x000a0dff;
>
>  void __stack_chk_fail(void)
>  {
> @@ -150,8 +145,6 @@ decompress_kernel(unsigned long output_start, unsigned long free_mem_ptr_p,
>  {
>         int ret;
>
> -       __stack_chk_guard_setup();
> -
>         output_data             = (unsigned char *)output_start;
>         free_mem_ptr            = free_mem_ptr_p;
>         free_mem_end_ptr        = free_mem_ptr_end_p;
> diff --git a/arch/mips/boot/compressed/decompress.c b/arch/mips/boot/compressed/decompress.c
> index fdf99e9..0694b3f 100644
> --- a/arch/mips/boot/compressed/decompress.c
> +++ b/arch/mips/boot/compressed/decompress.c
> @@ -76,12 +76,7 @@ void error(char *x)
>  #include "../../../../lib/decompress_unxz.c"
>  #endif
>
> -unsigned long __stack_chk_guard;
> -
> -void __stack_chk_guard_setup(void)
> -{
> -       __stack_chk_guard = 0x000a0dff;
> -}
> +unsigned long __stack_chk_guard = 0x000a0dff;
>
>  void __stack_chk_fail(void)
>  {
> @@ -92,8 +87,6 @@ void decompress_kernel(unsigned long boot_heap_start)
>  {
>         unsigned long zimage_start, zimage_size;
>
> -       __stack_chk_guard_setup();
> -
>         zimage_start = (unsigned long)(&__image_begin);
>         zimage_size = (unsigned long)(&__image_end) -
>             (unsigned long)(&__image_begin);
> diff --git a/arch/sh/boot/compressed/misc.c b/arch/sh/boot/compressed/misc.c
> index 627ce8e..2c564c2 100644
> --- a/arch/sh/boot/compressed/misc.c
> +++ b/arch/sh/boot/compressed/misc.c
> @@ -104,12 +104,7 @@ static void error(char *x)
>         while(1);       /* Halt */
>  }
>
> -unsigned long __stack_chk_guard;
> -
> -void __stack_chk_guard_setup(void)
> -{
> -       __stack_chk_guard = 0x000a0dff;
> -}
> +unsigned long __stack_chk_guard = 0x000a0dff;
>
>  void __stack_chk_fail(void)
>  {
> @@ -130,8 +125,6 @@ void decompress_kernel(void)
>  {
>         unsigned long output_addr;
>
> -       __stack_chk_guard_setup();
> -
>  #ifdef CONFIG_SUPERH64
>         output_addr = (CONFIG_MEMORY_START + 0x2000);
>  #else
> --
> 2.7.0
>