ARMv8.3 adds pointer authentication extension, which in this case allows
to ensure that, when offloaded to stack, return address is same at return
as at entry to the subroutine. The new instructions are nops on processors
that don't implement the extension, so that the vetification is backward
compatible.
Reviewed-by: Kurt Roeckx <kurt@roeckx.be>
Reviewed-by: Richard Levitte <levitte@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/8205)
(cherry picked from commit 9a18aae5f2)
Even though no test could be found to trigger this, paper-n-pencil
estimate suggests that x86 and ARM inner loop lazy reductions can
loose a bit in H4>>*5+H0 step.
Reviewed-by: Emilia Käsper <emilia@openssl.org>
Formally only 32-bit AVX2 code path needs this, but I choose to
harmonize all vector code paths.
RT#4346
Reviewed-by: Richard Levitte <levitte@openssl.org>
