This is a note to let you know that I've just added the patch titled
arm64: Make sure SPsel is always set
to the 3.18-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
arm64-make-sure-spsel-is-always-set.patch
and it can be found in the queue-3.18 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 5371513fb338fb9989c569dc071326d369d6ade8 Mon Sep 17 00:00:00 2001
From: Marc Zyngier <marc.zyngier@xxxxxxx>
Date: Tue, 26 Sep 2017 15:57:16 +0100
Subject: arm64: Make sure SPsel is always set
From: Marc Zyngier <marc.zyngier@xxxxxxx>
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@xxxxxxx>
Signed-off-by: Marc Zyngier <marc.zyngier@xxxxxxx>
Signed-off-by: Will Deacon <will.deacon@xxxxxxx>
Signed-off-by: Catalin Marinas <catalin.marinas@xxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
arch/arm64/kernel/head.S | 1 +
1 file changed, 1 insertion(+)
--- a/arch/arm64/kernel/head.S
+++ b/arch/arm64/kernel/head.S
@@ -264,6 +264,7 @@ 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
Patches currently in stable-queue which might be from marc.zyngier@xxxxxxx are
queue-3.18/arm64-make-sure-spsel-is-always-set.patch