3.16.52-rc1 review patch. If anyone has any objections, please let me know.
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From: Marc Zyngier marc.zyngier@arm.com
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 mark.rutland@arm.com Signed-off-by: Marc Zyngier marc.zyngier@arm.com Signed-off-by: Will Deacon will.deacon@arm.com Signed-off-by: Catalin Marinas catalin.marinas@arm.com Signed-off-by: Ben Hutchings ben@decadent.org.uk --- arch/arm64/kernel/head.S | 1 + 1 file changed, 1 insertion(+)
--- a/arch/arm64/kernel/head.S +++ b/arch/arm64/kernel/head.S @@ -269,6 +269,7 @@ ENDPROC(stext) * 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