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arm64: hyp-stub: Stop pointlessly clobbering lr

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When entering the kernel hyp stub, we check whether or not we've
made it here through an HVC instruction, clobbering lr (aka x30)
in the process.

This is completely pointless, as HVC is the only way to get here
(all traps to EL2 are disabled, no interrupt override is applied).

So let's remove this bit of code whose only point is to corrupt
a valuable register.

Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <cdall@linaro.org>
This commit is contained in:
Marc Zyngier
2017-04-03 19:37:34 +01:00
committed by Christoffer Dall
parent 9d0d4d34d9
commit 50d912cc3e
1 changed files with 0 additions and 6 deletions
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6
arch/arm64/kernel/hyp-stub.S
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@@ -55,12 +55,6 @@ ENDPROC(__hyp_stub_vectors)
.align 11
el1_sync:
mrs x30, esr_el2
lsr x30, x30, #ESR_ELx_EC_SHIFT
cmp x30, #ESR_ELx_EC_HVC64
b.ne 9f // Not an HVC trap
cmp x0, #HVC_GET_VECTORS
b.ne 1f
mrs x0, vbar_el2