Re: [PATCH 1/3] x86/asm/entry/32: Massage SYSENTER32 fast path to be nearly identical to SYSCALL32

[Andy Lutomirski]

On Fri, Jul 24, 2015 at 6:47 AM, Denys Vlasenko <dvlasenk@xxxxxxxxxx> wrote:
> This change swaps a few instructions in final register restoring/zeroing
> section of SYSENTER fast path, and adds/deletes a few empty lines.
>
> After this, the difference between SYSENTER and SYCALL fast paths
> (after the prologue which saved pt_regs) is very small:
> they differ merely in the choice of register to hold arg6 (EBP or R9)
> and in the value of EDX on exit: SYSENTER ABI doesn't need to preserve it,
> so it is zeroed. SYSCALL preserves it:

Reviewed-by: Andy Lutomirski <luto@xxxxxxxxxx>
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