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SubjectRe: [PATCH] x86-64/entry: add instruction suffix to SYSRET
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> On Dec 10, 2019, at 2:48 AM, Jan Beulich <JBeulich@suse.com> wrote:
>
> Omitting 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@suse.com>
>
> --- a/arch/x86/entry/entry_64.S
> +++ b/arch/x86/entry/entry_64.S
> @@ -1728,7 +1728,7 @@ END(nmi)
> SYM_CODE_START(ignore_sysret)
> UNWIND_HINT_EMPTY
> mov $-ENOSYS, %eax
> - sysret
> + sysretl

Isn’t the default sysretq? sysretl looks more correct, but that suggests that your changelog is wrong.

Is this code even reachable?

> SYM_CODE_END(ignore_sysret)
> #endif
>

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