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 <bsinghar...@gmail.com>
Signed-off-by: Ram Pai <linux...@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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