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Subject[PATCH v9 12/51] powerpc: ability to associate pkey to a vma
Date
arch-independent code expects the arch to  map
a pkey into the vma's protection bit setting.
The patch provides that ability.

Signed-off-by: Ram Pai <linuxram@us.ibm.com>
---
arch/powerpc/include/asm/mman.h | 7 ++++++-
arch/powerpc/include/asm/pkeys.h | 11 +++++++++++
arch/powerpc/mm/pkeys.c | 8 ++++++++
3 files changed, 25 insertions(+), 1 deletions(-)

diff --git a/arch/powerpc/include/asm/mman.h b/arch/powerpc/include/asm/mman.h
index 30922f6..2999478 100644
--- a/arch/powerpc/include/asm/mman.h
+++ b/arch/powerpc/include/asm/mman.h
@@ -13,6 +13,7 @@

#include <asm/cputable.h>
#include <linux/mm.h>
+#include <linux/pkeys.h>
#include <asm/cpu_has_feature.h>

/*
@@ -22,7 +23,11 @@
static inline unsigned long arch_calc_vm_prot_bits(unsigned long prot,
unsigned long pkey)
{
- return (prot & PROT_SAO) ? VM_SAO : 0;
+#ifdef CONFIG_PPC_MEM_KEYS
+ return (((prot & PROT_SAO) ? VM_SAO : 0) | pkey_to_vmflag_bits(pkey));
+#else
+ return ((prot & PROT_SAO) ? VM_SAO : 0);
+#endif
}
#define arch_calc_vm_prot_bits(prot, pkey) arch_calc_vm_prot_bits(prot, pkey)

diff --git a/arch/powerpc/include/asm/pkeys.h b/arch/powerpc/include/asm/pkeys.h
index 20d1f0e..1bd41ef 100644
--- a/arch/powerpc/include/asm/pkeys.h
+++ b/arch/powerpc/include/asm/pkeys.h
@@ -41,6 +41,17 @@
#define ARCH_VM_PKEY_FLAGS (VM_PKEY_BIT0 | VM_PKEY_BIT1 | VM_PKEY_BIT2 | \
VM_PKEY_BIT3 | VM_PKEY_BIT4)

+/* Override any generic PKEY permission defines */
+#define PKEY_DISABLE_EXECUTE 0x4
+#define PKEY_ACCESS_MASK (PKEY_DISABLE_ACCESS | \
+ PKEY_DISABLE_WRITE | \
+ PKEY_DISABLE_EXECUTE)
+
+static inline u64 pkey_to_vmflag_bits(u16 pkey)
+{
+ return (((u64)pkey << VM_PKEY_SHIFT) & ARCH_VM_PKEY_FLAGS);
+}
+
#define arch_max_pkey() pkeys_total

#define pkey_alloc_mask(pkey) (0x1 << pkey)
diff --git a/arch/powerpc/mm/pkeys.c b/arch/powerpc/mm/pkeys.c
index 5da94fe..4d704ea 100644
--- a/arch/powerpc/mm/pkeys.c
+++ b/arch/powerpc/mm/pkeys.c
@@ -39,6 +39,14 @@ void __init pkey_initialize(void)
(PKEY_DISABLE_ACCESS | PKEY_DISABLE_WRITE));

/*
+ * pkey_to_vmflag_bits() assumes that the pkey bits are contiguous
+ * in the vmaflag. Make sure that is really the case.
+ */
+ BUILD_BUG_ON(__builtin_clzl(ARCH_VM_PKEY_FLAGS >> VM_PKEY_SHIFT) +
+ __builtin_popcountl(ARCH_VM_PKEY_FLAGS >> VM_PKEY_SHIFT)
+ != (sizeof(u64) * BITS_PER_BYTE));
+
+ /*
* Disable the pkey system till everything is in place. A subsequent
* patch will enable it.
*/
--
1.7.1
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