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Subject[PATCH v9 03/51] powerpc: initial pkey plumbing
Date
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@us.ibm.com>
---
arch/powerpc/Kconfig | 15 ++++++++
arch/powerpc/include/asm/mmu_context.h | 5 +++
arch/powerpc/include/asm/pkeys.h | 57 ++++++++++++++++++++++++++++++++
arch/powerpc/mm/Makefile | 1 +
arch/powerpc/mm/hash_utils_64.c | 4 ++
arch/powerpc/mm/pkeys.c | 30 +++++++++++++++++
6 files changed, 112 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 cb782ac..9fd389b 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -865,6 +865,21 @@ config SECCOMP

If unsure, say Y. Only embedded should say N here.

+config PPC_MEM_KEYS
+ prompt "PowerPC Memory Protection Keys"
+ def_bool y
+ depends on PPC_BOOK3S_64
+ 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 492d814..2c24447 100644
--- a/arch/powerpc/include/asm/mmu_context.h
+++ b/arch/powerpc/include/asm/mmu_context.h
@@ -142,5 +142,10 @@ static inline bool arch_vma_access_permitted(struct vm_area_struct *vma,
/* by default, allow everything */
return true;
}
+
+#ifndef CONFIG_PPC_MEM_KEYS
+#define pkey_initialize()
+#endif /* CONFIG_PPC_MEM_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..a54cb39
--- /dev/null
+++ b/arch/powerpc/include/asm/pkeys.h
@@ -0,0 +1,57 @@
+/*
+ * PowerPC Memory Protection Keys management
+ * Copyright (c) 2017, IBM Corporation.
+ * Author: Ram Pai <linuxram@us.ibm.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ */
+
+#ifndef _ASM_POWERPC_KEYS_H
+#define _ASM_POWERPC_KEYS_H
+
+#include <linux/jump_label.h>
+
+DECLARE_STATIC_KEY_TRUE(pkey_disabled);
+#define ARCH_VM_PKEY_FLAGS 0
+
+static inline bool mm_pkey_is_allocated(struct mm_struct *mm, int pkey)
+{
+ return false;
+}
+
+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_POWERPC_KEYS_H */
diff --git a/arch/powerpc/mm/Makefile b/arch/powerpc/mm/Makefile
index a0c327d..823b03d 100644
--- a/arch/powerpc/mm/Makefile
+++ b/arch/powerpc/mm/Makefile
@@ -44,3 +44,4 @@ 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_PPC_MEM_KEYS) += pkeys.o
diff --git a/arch/powerpc/mm/hash_utils_64.c b/arch/powerpc/mm/hash_utils_64.c
index 578d5a3..1e74590 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>
@@ -1050,6 +1051,9 @@ void __init hash__early_init_mmu(void)
pr_info("Initializing hash mmu with SLB\n");
/* Initialize SLB management */
slb_initialize();
+
+ /* initialize the key subsystem */
+ pkey_initialize();
}

#ifdef CONFIG_SMP
diff --git a/arch/powerpc/mm/pkeys.c b/arch/powerpc/mm/pkeys.c
new file mode 100644
index 0000000..c97a7a0
--- /dev/null
+++ b/arch/powerpc/mm/pkeys.c
@@ -0,0 +1,30 @@
+/*
+ * PowerPC Memory Protection Keys management
+ * Copyright (c) 2017, IBM Corporation.
+ * Author: Ram Pai <linuxram@us.ibm.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ */
+
+#include <linux/pkeys.h>
+
+DEFINE_STATIC_KEY_TRUE(pkey_disabled);
+bool pkey_execute_disable_supported;
+
+void __init pkey_initialize(void)
+{
+ /*
+ * Disable the pkey system till everything is in place. A subsequent
+ * patch will enable it.
+ */
+ static_branch_enable(&pkey_disabled);
+
+ /*
+ * Disable execute_disable support for now. A subsequent patch will
+ * enable it.
+ */
+ pkey_execute_disable_supported = false;
+}
--
1.7.1
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