diff mbox

[RFC,v4,01/17] mm: introduce an additional vma bit for powerpc pkey

Message ID 1498558319-32466-2-git-send-email-linuxram@us.ibm.com (mailing list archive)
State Superseded
Headers show

Commit Message

Ram Pai June 27, 2017, 10:11 a.m. UTC 
Currently there are only 4bits in the vma flags to support 16 keys
on x86.  powerpc supports 32 keys, which needs 5bits. This patch
introduces an addition bit in the vma flags.

Signed-off-by: Ram Pai <linuxram@us.ibm.com>
---
 fs/proc/task_mmu.c |  6 +++++-
 include/linux/mm.h | 18 +++++++++++++-----
 2 files changed, 18 insertions(+), 6 deletions(-)

Comments

Balbir Singh June 27, 2017, 10:54 a.m. UTC | #1 
On Tue, 2017-06-27 at 03:11 -0700, Ram Pai wrote:
> Currently there are only 4bits in the vma flags to support 16 keys
> on x86.  powerpc supports 32 keys, which needs 5bits. This patch
> introduces an addition bit in the vma flags.
> 
> Signed-off-by: Ram Pai <linuxram@us.ibm.com>
> ---
>  fs/proc/task_mmu.c |  6 +++++-
>  include/linux/mm.h | 18 +++++++++++++-----
>  2 files changed, 18 insertions(+), 6 deletions(-)
> 
> diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c
> index f0c8b33..2ddc298 100644
> --- a/fs/proc/task_mmu.c
> +++ b/fs/proc/task_mmu.c
> @@ -666,12 +666,16 @@ static void show_smap_vma_flags(struct seq_file *m, struct vm_area_struct *vma)
>  		[ilog2(VM_MERGEABLE)]	= "mg",
>  		[ilog2(VM_UFFD_MISSING)]= "um",
>  		[ilog2(VM_UFFD_WP)]	= "uw",
> -#ifdef CONFIG_X86_INTEL_MEMORY_PROTECTION_KEYS
> +#ifdef CONFIG_ARCH_HAS_PKEYS
>  		/* These come out via ProtectionKey: */
>  		[ilog2(VM_PKEY_BIT0)]	= "",
>  		[ilog2(VM_PKEY_BIT1)]	= "",
>  		[ilog2(VM_PKEY_BIT2)]	= "",
>  		[ilog2(VM_PKEY_BIT3)]	= "",
> +#endif /* CONFIG_ARCH_HAS_PKEYS */
> +#ifdef CONFIG_PPC64_MEMORY_PROTECTION_KEYS
> +		/* Additional bit in ProtectionKey: */
> +		[ilog2(VM_PKEY_BIT4)]	= "",
>  #endif

Not sure why these are linked with smap bits, but I guess the keys live
in the Supervisor Mode Access Prevention area?

Balbir Singh.
diff mbox

Patch

diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c
index f0c8b33..2ddc298 100644
--- a/fs/proc/task_mmu.c
+++ b/fs/proc/task_mmu.c
@@ -666,12 +666,16 @@  static void show_smap_vma_flags(struct seq_file *m, struct vm_area_struct *vma)
 		[ilog2(VM_MERGEABLE)]	= "mg",
 		[ilog2(VM_UFFD_MISSING)]= "um",
 		[ilog2(VM_UFFD_WP)]	= "uw",
-#ifdef CONFIG_X86_INTEL_MEMORY_PROTECTION_KEYS
+#ifdef CONFIG_ARCH_HAS_PKEYS
 		/* These come out via ProtectionKey: */
 		[ilog2(VM_PKEY_BIT0)]	= "",
 		[ilog2(VM_PKEY_BIT1)]	= "",
 		[ilog2(VM_PKEY_BIT2)]	= "",
 		[ilog2(VM_PKEY_BIT3)]	= "",
+#endif /* CONFIG_ARCH_HAS_PKEYS */
+#ifdef CONFIG_PPC64_MEMORY_PROTECTION_KEYS
+		/* Additional bit in ProtectionKey: */
+		[ilog2(VM_PKEY_BIT4)]	= "",
 #endif
 	};
 	size_t i;
diff --git a/include/linux/mm.h b/include/linux/mm.h
index 7cb17c6..3d35bcc 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -208,21 +208,29 @@  extern int overcommit_kbytes_handler(struct ctl_table *, int, void __user *,
 #define VM_HIGH_ARCH_BIT_1	33	/* bit only usable on 64-bit architectures */
 #define VM_HIGH_ARCH_BIT_2	34	/* bit only usable on 64-bit architectures */
 #define VM_HIGH_ARCH_BIT_3	35	/* bit only usable on 64-bit architectures */
+#define VM_HIGH_ARCH_BIT_4	36	/* bit only usable on 64-bit arch */
 #define VM_HIGH_ARCH_0	BIT(VM_HIGH_ARCH_BIT_0)
 #define VM_HIGH_ARCH_1	BIT(VM_HIGH_ARCH_BIT_1)
 #define VM_HIGH_ARCH_2	BIT(VM_HIGH_ARCH_BIT_2)
 #define VM_HIGH_ARCH_3	BIT(VM_HIGH_ARCH_BIT_3)
+#define VM_HIGH_ARCH_4	BIT(VM_HIGH_ARCH_BIT_4)
 #endif /* CONFIG_ARCH_USES_HIGH_VMA_FLAGS */
 
-#if defined(CONFIG_X86)
-# define VM_PAT		VM_ARCH_1	/* PAT reserves whole VMA at once (x86) */
-#if defined (CONFIG_X86_INTEL_MEMORY_PROTECTION_KEYS)
+#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_BIT0	VM_HIGH_ARCH_0
 # define VM_PKEY_BIT1	VM_HIGH_ARCH_1
 # define VM_PKEY_BIT2	VM_HIGH_ARCH_2
 # define VM_PKEY_BIT3	VM_HIGH_ARCH_3
-#endif
+#endif /* CONFIG_ARCH_HAS_PKEYS */
+
+#if defined(CONFIG_PPC64_MEMORY_PROTECTION_KEYS)
+# define VM_PKEY_BIT4	VM_HIGH_ARCH_4 /* additional key bit used on ppc64 */
+#endif /* CONFIG_PPC64_MEMORY_PROTECTION_KEYS */
+
+
+#if defined(CONFIG_X86)
+# define VM_PAT		VM_ARCH_1	/* PAT reserves whole VMA at once (x86) */
 #elif defined(CONFIG_PPC)
 # define VM_SAO		VM_ARCH_1	/* Strong Access Ordering (powerpc) */
 #elif defined(CONFIG_PARISC)