Re: [PATCH 14/17] arm64: add __nocfi to functions that jump to a physical address

From: Kees Cook
Date: Thu Mar 11 2021 - 21:48:44 EST


On Thu, Mar 11, 2021 at 04:49:16PM -0800, Sami Tolvanen wrote:
> Disable CFI checking for functions that switch to linear mapping and
> make an indirect call to a physical address, since the compiler only
> understands virtual addresses and the CFI check for such indirect calls
> would always fail.
>
> Signed-off-by: Sami Tolvanen <samitolvanen@xxxxxxxxxx>

(I wonder if there is some value in a separate macro for "makes a PA
call"? Might other things care about that besides just CFI?)

Reviewed-by: Kees Cook <keescook@xxxxxxxxxxxx>

--
Kees Cook