Re: [RFC PATCH 01/11] x86: kernel FineIBT

[Sami Tolvanen]

On Wed, May 4, 2022 at 11:17 AM Peter Zijlstra <peterz@xxxxxxxxxxxxx> wrote:
> __cfi_\sym:                                     __cfi_\sym:
>                                                         int3; int3                              # 2
>         endbr                   # 4                     mov     \hash, %eax                     # 5
>         call    __fineibt_\hash # 5                     int3; int3                              # 2
> \sym:                                           \sym:

OK, that looks reasonable to me.

> It seems to preserve the properties of the last one in that direct calls
> will already be correct and we don't need linker fixups, and objtool can
> simply parse the preamble as regular instructions without needing
> further help.

Wouldn't objtool still print out unreachable instruction warnings here?

Sami