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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>
Marc Zyngier 8 jaren geleden
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commit
1edb632133
1 gewijzigde bestanden met toevoegingen van 0 en 1 verwijderingen
  1. 0 1
      arch/arm/kvm/hyp/hyp-entry.S

+ 0 - 1
arch/arm/kvm/hyp/hyp-entry.S

@@ -144,7 +144,6 @@ hyp_hvc:
 	ldr	r1, [r1]
 	ldr	ip, =__kvm_handle_stub_hvc
 	sub	ip, ip, r1
-THUMB(	add	ip, ip, #1)
 	pop	{r1}
 
 	bx	ip