Re: [PATCH v3 0/7] crypto: x86: Fix indirect function call casts
From: Eric Biggers
Date: Thu May 09 2019 - 13:59:40 EST
On Thu, May 09, 2019 at 08:38:28AM -0700, Sami Tolvanen wrote:
> On Wed, May 08, 2019 at 07:04:40PM -0700, Eric Biggers wrote:
> > And I also asked whether indirect calls to asm code are even allowed
> > with CFI. IIRC, the AOSP kernels have been patched to remove them from
> > arm64
>
> At least with clang, indirect calls to stand-alone assembly functions
> trip CFI checks, which is why Android kernels use static inline stubs
> to convert these to direct calls instead.
>
> Sami
Thanks Sami. Is there any way to annotate assembly functions such that they
work directly with CFI? Otherwise, we need the wrapper functions.
Kees and Joao, it would be helpful if you'd explain this in the patchset.
- Eric