[PATCH v3 3/3] kasan: arm64: support specialized outlined tag mismatch checks

[Will Deacon]

On Tue, Dec 08, 2020 at 05:49:07PM +0000, Catalin Marinas wrote:
> On Wed, Dec 02, 2020 at 09:12:24PM -0800, Peter Collingbourne wrote:
> > By using outlined checks we can achieve a significant code size
> > improvement by moving the tag-based ASAN checks into separate
> > functions. Unlike the existing CONFIG_KASAN_OUTLINE mode these
> > functions have a custom calling convention that preserves most
> > registers and is specialized to the register containing the address
> > and the type of access, and as a result we can eliminate the code
> > size and performance overhead of a standard calling convention such
> > as AAPCS for these functions.

[...]

> >  arch/arm64/include/asm/asm-prototypes.h |  6 ++
> >  arch/arm64/include/asm/module.lds.h     | 17 +++++-
> >  arch/arm64/lib/Makefile                 |  2 +
> >  arch/arm64/lib/kasan_sw_tags.S          | 76 +++++++++++++++++++++++++
> >  mm/kasan/tags.c                         |  7 +++
> >  scripts/Makefile.kasan                  |  1 +
> 
> I can try to queue the series but this patch would need an ack on the
> kasan changes.
> 
> (also, it may conflict with linux-next which renames tags.c to sw_tags.c
> but that's trivial)

Looks like this didn't land for 5.11. Peter -- please can you send a rebased
version (on -rc4) so that I can queue it for 5.12?

Thanks,

Will