From 638e7874f68208d18d392cdd61ba389e53f6bb0c Mon Sep 17 00:00:00 2001 From: Marc Zyngier Date: Tue, 26 Sep 2017 15:57:16 +0100 Subject: [PATCH] arm64: Make sure SPsel is always set commit 5371513fb338fb9989c569dc071326d369d6ade8 upstream. When the kernel is entered at EL2 on an ARMv8.0 system, we construct the EL1 pstate and make sure this uses the the EL1 stack pointer (we perform an exception return to EL1h). But if the kernel is either entered at EL1 or stays at EL2 (because we're on a VHE-capable system), we fail to set SPsel, and use whatever stack selection the higher exception level has choosen for us. Let's not take any chance, and make sure that SPsel is set to one before we decide the mode we're going to run in. Acked-by: Mark Rutland Signed-off-by: Marc Zyngier Signed-off-by: Will Deacon Signed-off-by: Catalin Marinas Signed-off-by: Greg Kroah-Hartman --- arch/arm64/kernel/head.S | 1 + 1 file changed, 1 insertion(+) diff --git a/arch/arm64/kernel/head.S b/arch/arm64/kernel/head.S index 20ceb5edf7b89..d019c3a58cc28 100644 --- a/arch/arm64/kernel/head.S +++ b/arch/arm64/kernel/head.S @@ -446,6 +446,7 @@ ENDPROC(__mmap_switched) * booted in EL1 or EL2 respectively. */ ENTRY(el2_setup) + msr SPsel, #1 // We want to use SP_EL{1,2} mrs x0, CurrentEL cmp x0, #CurrentEL_EL2 b.ne 1f -- 2.47.3