Document the fact that we enable pointer authentication protection for
leaf functions since there is some narrow potential for ROP protection
benefits and little overhead has been observed.
Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20200506195138.22086-2-broonie@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>