Re: [PATCH 3/9] x86/asm: Fix register order

[Josh Poimboeuf]

On Wed, Oct 13, 2021 at 02:22:20PM +0200, Peter Zijlstra wrote:
> Ensure the register order is correct; this allows for easy translation
> between register number and trampoline and vice-versa.
> 
> Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>

It would be wise to add a comment saying the register order is critical
to the functioning of the system and shouldn't be changed.

> ---
>  arch/x86/include/asm/GEN-for-each-reg.h |   10 ++++++----
>  1 file changed, 6 insertions(+), 4 deletions(-)
> 
> --- a/arch/x86/include/asm/GEN-for-each-reg.h
> +++ b/arch/x86/include/asm/GEN-for-each-reg.h
> @@ -1,11 +1,12 @@
>  #ifdef CONFIG_64BIT
>  GEN(rax)
> -GEN(rbx)
>  GEN(rcx)
>  GEN(rdx)
> +GEN(rbx)
> +GEN(rsp)
> +GEN(rbp)
>  GEN(rsi)
>  GEN(rdi)
> -GEN(rbp)
>  GEN(r8)
>  GEN(r9)
>  GEN(r10)
> @@ -16,10 +17,11 @@ GEN(r14)
>  GEN(r15)
>  #else
>  GEN(eax)
> -GEN(ebx)
>  GEN(ecx)
>  GEN(edx)
> +GEN(ebx)
> +GEN(esp)
> +GEN(ebp)
>  GEN(esi)
>  GEN(edi)
> -GEN(ebp)
>  #endif

-- 
Josh