Re: [PATCH] x86-64/entry: add instruction suffix to SYSRET
From: Andy Lutomirski
Date: Tue Dec 10 2019 - 10:29:56 EST
> On Dec 10, 2019, at 2:48 AM, Jan Beulich <JBeulich@xxxxxxxx> wrote:
> ïOmitting suffixes from instructions in AT&T mode is bad practice when
> operand size cannot be determined by the assembler from register
> operands, and is likely going to be warned about by upstream gas in the
> future. Add the missing suffix here.
> Signed-off-by: Jan Beulich <jbeulich@xxxxxxxx>
> --- a/arch/x86/entry/entry_64.S
> +++ b/arch/x86/entry/entry_64.S
> @@ -1728,7 +1728,7 @@ END(nmi)
> mov $-ENOSYS, %eax
> - sysret
> + sysretl
Isnât the default sysretq? sysretl looks more correct, but that suggests that your changelog is wrong.
Is this code even reachable?