Re: [PATCH v5 06/20] x86/decompressor: Store boot_params pointer in callee save register

[Borislav Petkov]

On Wed, Jun 07, 2023 at 09:23:28AM +0200, Ard Biesheuvel wrote:
> Instead of pushing and popping %RSI several times to preserve the struct
> boot_params pointer across the execution of the startup code, move it
> into a callee save register before the first call into C, and copy it
> back when needed.
> 
> Signed-off-by: Ard Biesheuvel <ardb@xxxxxxxxxx>
> ---
>  arch/x86/boot/compressed/head_64.S | 34 +++++++-------------
>  1 file changed, 11 insertions(+), 23 deletions(-)

I like that.

We do a similar dance in arch/x86/kernel/head_64.S. Care to fix that
too, in a separate patch?

Thx.

-- 
Regards/Gruss,
    Boris.

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