From e10cc8715d180509a367d3ab25d40e4a1612cb2f Mon Sep 17 00:00:00 2001
From: "Aneesh Kumar K.V" <aneesh.kumar@linux.ibm.com>
Date: Thu, 9 Jul 2020 08:59:37 +0530
Subject: [PATCH] powerpc/book3s64/kuep: Add MMU_FTR_KUEP
References: jsc#SLE-16556 bsc#1078248 FATE#322447
Patch-mainline: v5.9-rc1
Git-commit: e10cc8715d180509a367d3ab25d40e4a1612cb2f
This will be used to enable/disable Kernel Userspace Execution
Prevention (KUEP).
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200709032946.881753-15-aneesh.kumar@linux.ibm.com
Acked-by: Michal Suchanek <msuchanek@suse.de>
---
arch/powerpc/include/asm/mmu.h | 9 +++++++++
arch/powerpc/mm/book3s64/radix_pgtable.c | 4 +++-
2 files changed, 12 insertions(+), 1 deletion(-)
diff --git a/arch/powerpc/include/asm/mmu.h b/arch/powerpc/include/asm/mmu.h
index 17cbaf132631..255a1837e9f7 100644
--- a/arch/powerpc/include/asm/mmu.h
+++ b/arch/powerpc/include/asm/mmu.h
@@ -28,6 +28,11 @@
* Individual features below.
*/
+/*
+ * Support for KUEP feature.
+ */
+#define MMU_FTR_KUEP ASM_CONST(0x00000400)
+
/*
* Support for memory protection keys.
*/
@@ -189,6 +194,10 @@ enum {
#ifdef CONFIG_PPC_MEM_KEYS
MMU_FTR_PKEY |
#endif
+#ifdef CONFIG_PPC_KUEP
+ MMU_FTR_KUEP |
+#endif /* CONFIG_PPC_KUAP */
+
0,
};
diff --git a/arch/powerpc/mm/book3s64/radix_pgtable.c b/arch/powerpc/mm/book3s64/radix_pgtable.c
index c5bf2ef73c36..3536675dd61e 100644
--- a/arch/powerpc/mm/book3s64/radix_pgtable.c
+++ b/arch/powerpc/mm/book3s64/radix_pgtable.c
@@ -593,8 +593,10 @@ void setup_kuep(bool disabled)
if (disabled || !early_radix_enabled())
return;
- if (smp_processor_id() == boot_cpuid)
+ if (smp_processor_id() == boot_cpuid) {
pr_info("Activating Kernel Userspace Execution Prevention\n");
+ cur_cpu_spec->mmu_features |= MMU_FTR_KUEP;
+ }
/*
* Radix always uses key0 of the IAMR to determine if an access is
--
2.26.2