On 15/02/2022 16:53, Jan Beulich wrote:
> On 14.02.2022 13:51, Andrew Cooper wrote:
>> UEFI Runtime services, at the time of writing, aren't CET-IBT compatible.
>> Work is ongoing to address this. In the meantime, unconditionally disable
>> IBT.
>>
>> Signed-off-by: Andrew Cooper <andrew.coop...@citrix.com>
> Reviewed-by: Jan Beulich <jbeul...@suse.com>
Thanks.
>
>> --- a/xen/common/efi/runtime.c
>> +++ b/xen/common/efi/runtime.c
>> @@ -21,6 +21,7 @@ struct efi_rs_state {
>> * don't strictly need that.
>> */
>> unsigned long __aligned(32) cr3;
>> + unsigned long msr_s_cet;
>> #endif
>> };
> The latest with the next addition here we will probably want to ...
>
>> @@ -113,6 +114,19 @@ struct efi_rs_state efi_rs_enter(void)
> ... no longer have this be the function's return type.
So about this.
why aren't we using __attribute__((force_align_arg_pointer)) ? It
exists in at least GCC 4.1 and Clang 6.
We're way way overdue bumping the minimum toolchain versions, and Clang
3.5=>6 is still very obsolete minimum version. This way, we're not
depending on some very subtle ABI mechanics to try and keep the stack
properly aligned.
~Andrew
