Re: the x86 sysret_rip test fails on the Intel FRED architecture

From: H. Peter Anvin
Date: Sat Jan 21 2023 - 23:45:06 EST


On January 21, 2023 8:34:09 PM PST, Dave Hansen <dave.hansen@xxxxxxxxx> wrote:
>On 1/21/23 19:38, Li, Xin3 wrote:
>>> However, it doesn't seem to make sense to do so to me. The current behavior is
>>> much more of an artifact than desired behavior.
>> We kind of have an agreement that %r11 = %flags after returning from the kernel.
>>
>> And the question is, is it what we want?
>
>Can the selftest just set r11=rflags before the syscall? The old
>syscall entry path will set r11=rflags. The FRED path won't touch it.
>Either case will pass an r11==rflags check.

That's a good idea.