[PATCH 01/25] powerpc: initial pkey plumbing
Ram Pai
linuxram at us.ibm.com
Sat Sep 9 08:44:49 AEST 2017
Basic plumbing to initialize the pkey system.
Nothing is enabled yet. A later patch will enable it
ones all the infrastructure is in place.
Signed-off-by: Ram Pai <linuxram at us.ibm.com>
---
arch/powerpc/Kconfig | 16 +++++++++++
arch/powerpc/include/asm/mmu_context.h | 5 +++
arch/powerpc/include/asm/pkeys.h | 45 ++++++++++++++++++++++++++++++++
arch/powerpc/kernel/setup_64.c | 4 +++
arch/powerpc/mm/Makefile | 1 +
arch/powerpc/mm/hash_utils_64.c | 1 +
arch/powerpc/mm/pkeys.c | 33 +++++++++++++++++++++++
7 files changed, 105 insertions(+), 0 deletions(-)
create mode 100644 arch/powerpc/include/asm/pkeys.h
create mode 100644 arch/powerpc/mm/pkeys.c
diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index 9fc3c0b..a4cd210 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -864,6 +864,22 @@ config SECCOMP
If unsure, say Y. Only embedded should say N here.
+config PPC64_MEMORY_PROTECTION_KEYS
+ prompt "PowerPC Memory Protection Keys"
+ def_bool y
+ # Note: only available in 64-bit mode
+ depends on PPC64
+ select ARCH_USES_HIGH_VMA_FLAGS
+ select ARCH_HAS_PKEYS
+ ---help---
+ Memory Protection Keys provides a mechanism for enforcing
+ page-based protections, but without requiring modification of the
+ page tables when an application changes protection domains.
+
+ For details, see Documentation/vm/protection-keys.txt
+
+ If unsure, say y.
+
endmenu
config ISA_DMA_API
diff --git a/arch/powerpc/include/asm/mmu_context.h b/arch/powerpc/include/asm/mmu_context.h
index 3095925..7badf29 100644
--- a/arch/powerpc/include/asm/mmu_context.h
+++ b/arch/powerpc/include/asm/mmu_context.h
@@ -141,5 +141,10 @@ static inline bool arch_vma_access_permitted(struct vm_area_struct *vma,
/* by default, allow everything */
return true;
}
+
+#ifndef CONFIG_PPC64_MEMORY_PROTECTION_KEYS
+#define pkey_initialize()
+#endif /* CONFIG_PPC64_MEMORY_PROTECTION_KEYS */
+
#endif /* __KERNEL__ */
#endif /* __ASM_POWERPC_MMU_CONTEXT_H */
diff --git a/arch/powerpc/include/asm/pkeys.h b/arch/powerpc/include/asm/pkeys.h
new file mode 100644
index 0000000..c02305a
--- /dev/null
+++ b/arch/powerpc/include/asm/pkeys.h
@@ -0,0 +1,45 @@
+#ifndef _ASM_PPC64_PKEYS_H
+#define _ASM_PPC64_PKEYS_H
+
+extern bool pkey_inited;
+extern bool pkey_execute_disable_support;
+#define ARCH_VM_PKEY_FLAGS 0
+
+static inline bool mm_pkey_is_allocated(struct mm_struct *mm, int pkey)
+{
+ return (pkey == 0);
+}
+
+static inline int mm_pkey_alloc(struct mm_struct *mm)
+{
+ return -1;
+}
+
+static inline int mm_pkey_free(struct mm_struct *mm, int pkey)
+{
+ return -EINVAL;
+}
+
+/*
+ * Try to dedicate one of the protection keys to be used as an
+ * execute-only protection key.
+ */
+static inline int execute_only_pkey(struct mm_struct *mm)
+{
+ return 0;
+}
+
+static inline int arch_override_mprotect_pkey(struct vm_area_struct *vma,
+ int prot, int pkey)
+{
+ return 0;
+}
+
+static inline int arch_set_user_pkey_access(struct task_struct *tsk, int pkey,
+ unsigned long init_val)
+{
+ return 0;
+}
+
+extern void pkey_initialize(void);
+#endif /*_ASM_PPC64_PKEYS_H */
diff --git a/arch/powerpc/kernel/setup_64.c b/arch/powerpc/kernel/setup_64.c
index b89c6aa..3b67014 100644
--- a/arch/powerpc/kernel/setup_64.c
+++ b/arch/powerpc/kernel/setup_64.c
@@ -37,6 +37,7 @@
#include <linux/memblock.h>
#include <linux/memory.h>
#include <linux/nmi.h>
+#include <linux/pkeys.h>
#include <asm/io.h>
#include <asm/kdump.h>
@@ -316,6 +317,9 @@ void __init early_setup(unsigned long dt_ptr)
/* Initialize the hash table or TLB handling */
early_init_mmu();
+ /* initialize the key subsystem */
+ pkey_initialize();
+
/*
* At this point, we can let interrupts switch to virtual mode
* (the MMU has been setup), so adjust the MSR in the PACA to
diff --git a/arch/powerpc/mm/Makefile b/arch/powerpc/mm/Makefile
index fb844d2..927620a 100644
--- a/arch/powerpc/mm/Makefile
+++ b/arch/powerpc/mm/Makefile
@@ -43,3 +43,4 @@ obj-$(CONFIG_PPC_COPRO_BASE) += copro_fault.o
obj-$(CONFIG_SPAPR_TCE_IOMMU) += mmu_context_iommu.o
obj-$(CONFIG_PPC_PTDUMP) += dump_linuxpagetables.o
obj-$(CONFIG_PPC_HTDUMP) += dump_hashpagetable.o
+obj-$(CONFIG_PPC64_MEMORY_PROTECTION_KEYS) += pkeys.o
diff --git a/arch/powerpc/mm/hash_utils_64.c b/arch/powerpc/mm/hash_utils_64.c
index 0dff57b..67f62b5 100644
--- a/arch/powerpc/mm/hash_utils_64.c
+++ b/arch/powerpc/mm/hash_utils_64.c
@@ -35,6 +35,7 @@
#include <linux/memblock.h>
#include <linux/context_tracking.h>
#include <linux/libfdt.h>
+#include <linux/pkeys.h>
#include <asm/debugfs.h>
#include <asm/processor.h>
diff --git a/arch/powerpc/mm/pkeys.c b/arch/powerpc/mm/pkeys.c
new file mode 100644
index 0000000..418a05b
--- /dev/null
+++ b/arch/powerpc/mm/pkeys.c
@@ -0,0 +1,33 @@
+/*
+ * PowerPC Memory Protection Keys management
+ * Copyright (c) 2015, Intel Corporation.
+ * Copyright (c) 2017, IBM Corporation.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
+ * more details.
+ */
+#include <linux/pkeys.h> /* PKEY_* */
+
+bool pkey_inited;
+bool pkey_execute_disable_support;
+
+void __init pkey_initialize(void)
+{
+ /* disable the pkey system till everything
+ * is in place. A patch further down the
+ * line will enable it.
+ */
+ pkey_inited = false;
+
+ /*
+ * disable execute_disable support for now.
+ * A patch further down will enable it.
+ */
+ pkey_execute_disable_support = false;
+}
--
1.7.1
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