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Subject[PATCH v10 02/27] mm, powerpc, x86: introduce an additional vma bit for powerpc pkey
Date
Currently only 4bits are allocated in the vma flags to hold 16
keys. This is sufficient for x86. PowerPC supports 32 keys,
which needs 5bits. This patch allocates an additional bit.

Acked-by: Balbir Singh <bsingharora@gmail.com>
Signed-off-by: Ram Pai <linuxram@us.ibm.com>
---
fs/proc/task_mmu.c | 1 +
include/linux/mm.h | 3 ++-
2 files changed, 3 insertions(+), 1 deletions(-)

diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c
index b139617..0edd4da 100644
--- a/fs/proc/task_mmu.c
+++ b/fs/proc/task_mmu.c
@@ -680,6 +680,7 @@ static void show_smap_vma_flags(struct seq_file *m, struct vm_area_struct *vma)
[ilog2(VM_PKEY_BIT1)] = "",
[ilog2(VM_PKEY_BIT2)] = "",
[ilog2(VM_PKEY_BIT3)] = "",
+ [ilog2(VM_PKEY_BIT4)] = "",
#endif /* CONFIG_ARCH_HAS_PKEYS */
};
size_t i;
diff --git a/include/linux/mm.h b/include/linux/mm.h
index 01381d3..ebcb997 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -231,9 +231,10 @@ extern int overcommit_kbytes_handler(struct ctl_table *, int, void __user *,
#ifdef CONFIG_ARCH_HAS_PKEYS
# define VM_PKEY_SHIFT VM_HIGH_ARCH_BIT_0
# define VM_PKEY_BIT0 VM_HIGH_ARCH_0 /* A protection key is a 4-bit value */
-# define VM_PKEY_BIT1 VM_HIGH_ARCH_1
+# define VM_PKEY_BIT1 VM_HIGH_ARCH_1 /* on x86 and 5-bit value on ppc64 */
# define VM_PKEY_BIT2 VM_HIGH_ARCH_2
# define VM_PKEY_BIT3 VM_HIGH_ARCH_3
+# define VM_PKEY_BIT4 VM_HIGH_ARCH_4
#endif /* CONFIG_ARCH_HAS_PKEYS */

#if defined(CONFIG_X86)
--
1.7.1
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