On Thu, Jul 11, 2024 at 07:49:25AM +0200, Jiri Slaby wrote:
Why not simply:
.macro CLEAR_CPU_BUFFERS_SAFE ALTERNATIVE "", __stringify(verw %ss:_ASM_RIP(mds_verw_sel)), X86_FEATURE_CLEAR_CPU_BUF .endm
We can do it this way as well. But, there are stable kernels that don't support relocations in ALTERNATIVEs. The way it is done in current patch can be backported without worrying about which kernels support relocations.
This sounds weird. There are code bases without ALTERNATIVE support at all. Will you expand ALTERNATIVE into some cmp & jmp here due to that? No.
Agree, will change it to the way Uros and Peter suggested.
Instead, you can send this "backport" to stable for older kernels later, once a proper patch is merged.
Ok, will take care of the differences in the backports.