ARM: KVM: Fix idmap stub entry when running Thumb-2 code
authorMarc Zyngier <marc.zyngier@arm.com>
Thu, 20 Apr 2017 15:02:21 +0000 (16:02 +0100)
committerChristoffer Dall <cdall@linaro.org>
Thu, 20 Apr 2017 18:17:57 +0000 (20:17 +0200)
commit1edb632133efb6226b6bef3e7d9fa8c7134ac4e2
tree8451658c150adde8d165549ab5d2f3249344e6b1
parent5b560525add78e15fd5b75e5d03ea1ff988e6747
ARM: KVM: Fix idmap stub entry when running Thumb-2 code

When entering the hyp stub implemented in the idmap, we try to
be mindful of the fact that we could be running a Thumb-2 kernel
by adding 1 to the address we compute. Unfortunately, the assembler
also knows about this trick, and has already generated an address
that has bit 0 set in the litteral pool.

Our superfluous correction ends up confusing the CPU entierely,
as we now branch to the stub in ARM mode instead of Thumb, and on
a possibly unaligned address for good measure. From that point,
nothing really good happens.

The obvious fix in to remove this stupid target PC correction.

Fixes: 6bebcecb6c5b ("ARM: KVM: Allow the main HYP code to use the init hyp stub implementation")
Reported-by: Christoffer Dall <cdall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <cdall@linaro.org>
arch/arm/kvm/hyp/hyp-entry.S