ARM has released the remaining MTE string routines, so let's start
using them. The strnlen implementation is now compatible with MTE,
so it no longer needs to be an ifunc.
Bug: 135772972
Change-Id: I9de7fb44447aa1b878f4ad3f62cb0129857b43ad
This includes optimized strrchr and strchrnul routines, and an MTE-compatible
strlen routine.
Bug: 135772972
Change-Id: I48499f757cdc6d3e77e5649123d45b17dfa3c6b0
As it turns out, our "generic" arm64 implementations of certain string.h
functions are not actually generic, since they will eagerly read memory
possibly outside of the bounds of an MTE granule, which may lead to a segfault
on MTE-enabled hardware. Therefore, move the implementations into a "default"
directory and use ifuncs to select between them and a new set of "mte"
implementations, conditional on whether the hardware and kernel support MTE.
The MTE implementations are currently naive implementations written in C
but will later be replaced with a set of optimized assembly implementations.
Bug: 135772972
Change-Id: Ife37c4e0e6fd60ff20a34594cc09c541af4d1dd7
