[PATCH] RISC-V: Double the stack size on rv64

[Colin Ian King]

On 14/07/2020 02:19, Palmer Dabbelt wrote:
> This was suggested in the syzkaller thread as a fix for a bunch of issues.  It
> seems in line with what other architectures are doing, and while I haven't
> personally figured out how to reproduce the issues they seem believable enough
> to just change it.
> 
> Fixes: 7db91e57a0ac ("RISC-V: Task implementation")
> Cc: stable at vger.kernel.org
> Signed-off-by: Palmer Dabbelt <palmerdabbelt at google.com>
> ---
> I've put this on fixes as I don't see a patch from anyone on that thread, and
> it seems straight-forward enough to just do it.  If there's any issues I'm
> happy to listen, otherwise this is going up later this week.
> ---
>  arch/riscv/include/asm/thread_info.h | 4 ++++
>  1 file changed, 4 insertions(+)
> 
> diff --git a/arch/riscv/include/asm/thread_info.h b/arch/riscv/include/asm/thread_info.h
> index 1dd12a0cbb2b..2026076b1d30 100644
> --- a/arch/riscv/include/asm/thread_info.h
> +++ b/arch/riscv/include/asm/thread_info.h
> @@ -12,7 +12,11 @@
>  #include <linux/const.h>
>  
>  /* thread information allocation */
> +#if defined(CONFIG_32BIT)
>  #define THREAD_SIZE_ORDER	(1)
> +#elif defined(CONFIG_64BIT)
> +#define THREAD_SIZE_ORDER   (2)
> +#endif
>  #define THREAD_SIZE		(PAGE_SIZE << THREAD_SIZE_ORDER)
>  
>  #ifndef __ASSEMBLY__
> 
FWIW, this fixes a gcov issue I was seeing.