ARM: hyp: initialize CNTVOFF to zero

commit 0af0b189abf73d232af782df2f999235cd2fed7f upstream.

In order to be able to use the virtual counter in a safe way,
make sure it is initialized to zero before dropping to SVC.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Cc: Dave Martin <dave.martin@linaro.org>
Cc: Mark Brown <broonie@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/arch/arm/kernel/hyp-stub.S b/arch/arm/kernel/hyp-stub.S
index 1315c4ccfa563a04928347ec560ed618dcd3f958..dbe21107945a53fd822614d3d02cd951277cbc23 100644 (file)
--- a/arch/arm/kernel/hyp-stub.S
+++ b/arch/arm/kernel/hyp-stub.S
@@ -153,6 +153,8 @@ THUMB(      orr     r7, #(1 << 30)  )       @ HSCTLR.TE
        mrc     p15, 4, r7, c14, c1, 0  @ CNTHCTL
        orr     r7, r7, #3              @ PL1PCEN | PL1PCTEN
        mcr     p15, 4, r7, c14, c1, 0  @ CNTHCTL
+       mov     r7, #0
+       mcrr    p15, 4, r7, r7, c14     @ CNTVOFF
 1:
 #endif