From: Will Deacon <will.deacon@xxxxxxx> This patch has been added to the 4.1 stable tree. If you have any objections, please let us know. =============== [ Upstream commit d8d23fa0f27f3b2942a7bbc7378c7735324ed519 ] We don't want to expose the DCC to userspace, particularly as there is a kernel console driver for it. This patch resets mdscr_el1 to disable userspace access to the DCC registers on the cold boot path. Signed-off-by: Will Deacon <will.deacon@xxxxxxx> Signed-off-by: Sasha Levin <sasha.levin@xxxxxxxxxx> --- arch/arm64/mm/proc.S | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/arch/arm64/mm/proc.S b/arch/arm64/mm/proc.S index cdd754e..d2c2e3b 100644 --- a/arch/arm64/mm/proc.S +++ b/arch/arm64/mm/proc.S @@ -202,7 +202,8 @@ ENTRY(__cpu_setup) mov x0, #3 << 20 msr cpacr_el1, x0 // Enable FP/ASIMD - msr mdscr_el1, xzr // Reset mdscr_el1 + mov x0, #1 << 12 // Reset mdscr_el1 and disable + msr mdscr_el1, x0 // access to the DCC from EL0 /* * Memory region attributes for LPAE: * -- 2.5.0 -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html