Marc Zyngier a8e4c0a919 arm64: Move BP hardening to check_and_switch_context
We call arm64_apply_bp_hardening() from post_ttbr_update_workaround,
which has the unexpected consequence of being triggered on every
exception return to userspace when ARM64_SW_TTBR0_PAN is selected,
even if no context switch actually occured.

This is a bit suboptimal, and it would be more logical to only
invalidate the branch predictor when we actually switch to
a different mm.

In order to solve this, move the call to arm64_apply_bp_hardening()
into check_and_switch_context(), where we're guaranteed to pick
a different mm context.

Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2018-01-23 15:40:29 +00:00
..
2017-08-10 18:13:59 +01:00
2017-02-09 13:47:56 +00:00
2017-07-20 17:03:53 +01:00
2017-05-08 17:15:13 -07:00
2017-12-22 17:35:21 +00:00