On Wed, 31 Oct 2018 13:56:58 +0000,
David Long <dave.long@xxxxxxxxxx> wrote:
>
> From: Russell King <rmk+kernel@xxxxxxxxxxxxxxx>
>
> Commit 10115105cb3aa17b5da1cb726ae8dd5f6854bd93 upstream.
>
> Add firmware based hardening for cores that require more complex
> handling in firmware.
>
> Signed-off-by: Russell King <rmk+kernel@xxxxxxxxxxxxxxx>
> Boot-tested-by: Tony Lindgren <tony@xxxxxxxxxxx>
> Reviewed-by: Tony Lindgren <tony@xxxxxxxxxxx>
> Reviewed-by: Marc Zyngier <marc.zyngier@xxxxxxx>
> Signed-off-by: David A. Long <dave.long@xxxxxxxxxx>
> ---
> arch/arm/mm/proc-v7-bugs.c | 60 ++++++++++++++++++++++++++++++++++++++
> arch/arm/mm/proc-v7.S | 21 +++++++++++++
> 2 files changed, 81 insertions(+)
>
[...]
> diff --git a/arch/arm/mm/proc-v7.S b/arch/arm/mm/proc-v7.S
> index 2d2e5ae85816..8fde9edb4a48 100644
> --- a/arch/arm/mm/proc-v7.S
> +++ b/arch/arm/mm/proc-v7.S
> @@ -9,6 +9,7 @@
> *
> * This is the "shell" of the ARMv7 processor support.
> */
> +#include <linux/arm-smccc.h>
> #include <linux/init.h>
> #include <linux/linkage.h>
> #include <asm/assembler.h>
> @@ -88,6 +89,26 @@ ENTRY(cpu_v7_dcache_clean_area)
> ret lr
> ENDPROC(cpu_v7_dcache_clean_area)
>
> +#ifdef CONFIG_ARM_PSCI
> + .arch_extension sec
> +ENTRY(cpu_v7_smc_switch_mm)
> + stmfd sp!, {r0 - r3}
> + movw r0, #:lower16:ARM_SMCCC_ARCH_WORKAROUND_1
> + movt r0, #:upper16:ARM_SMCCC_ARCH_WORKAROUND_1
> + smc #0
> + ldmfd sp!, {r0 - r3}
> + b cpu_v7_switch_mm
> +ENDPROC(cpu_v7_smc_switch_mm)
> + .arch_extension virt
> +ENTRY(cpu_v7_hvc_switch_mm)
> + stmfd sp!, {r0 - r3}
> + movw r0, #:lower16:ARM_SMCCC_ARCH_WORKAROUND_1
> + movt r0, #:upper16:ARM_SMCCC_ARCH_WORKAROUND_1
> + hvc #0
> + ldmfd sp!, {r0 - r3}
> + b cpu_v7_switch_mm
> +ENDPROC(cpu_v7_smc_switch_mm)
As pointed out by Ard a while ago [1], this breaks Thumb-2 kernels.
Please keep this series on hold until this is fixed in mainline and
you can cherry-pick the corresponding patch.
Thanks,
M.
[1] https://patchwork.kernel.org/patch/10475033/
--
Jazz is not dead, it just smell funny.
