mm: export stable page flags

Rename get_uflags() to stable_page_flags() and make it a global function
for use in the hwpoison page flags filter, which need to compare user
page flags with the value provided by user space.

Also move KPF_* to kernel-page-flags.h for use by user space tools.

Acked-by: Matt Mackall <mpm@selenic.com>
Signed-off-by: Andi Kleen <ak@linux.intel.com>
CC: Nick Piggin <npiggin@suse.de>
CC: Christoph Lameter <cl@linux-foundation.org>
Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
Signed-off-by: Andi Kleen <ak@linux.intel.com>

diff --git a/fs/proc/page.c b/fs/proc/page.c
index 5033ce0d254b90dcd0ca19162c6cbe9df254c87d..180cf5a0bd67119218c170b265cf944c103b889b 100644 (file)
--- a/fs/proc/page.c
+++ b/fs/proc/page.c
@@ -8,6 +8,7 @@
 #include <linux/proc_fs.h>
 #include <linux/seq_file.h>
 #include <linux/hugetlb.h>
+#include <linux/kernel-page-flags.h>
 #include <asm/uaccess.h>
 #include "internal.h"
 
@@ -71,52 +72,12 @@ static const struct file_operations proc_kpagecount_operations = {
  * physical page flags.
  */
 
-/* These macros are used to decouple internal flags from exported ones */
-
-#define KPF_LOCKED             0
-#define KPF_ERROR              1
-#define KPF_REFERENCED         2
-#define KPF_UPTODATE           3
-#define KPF_DIRTY              4
-#define KPF_LRU                        5
-#define KPF_ACTIVE             6
-#define KPF_SLAB               7
-#define KPF_WRITEBACK          8
-#define KPF_RECLAIM            9
-#define KPF_BUDDY              10
-
-/* 11-20: new additions in 2.6.31 */
-#define KPF_MMAP               11
-#define KPF_ANON               12
-#define KPF_SWAPCACHE          13
-#define KPF_SWAPBACKED         14
-#define KPF_COMPOUND_HEAD      15
-#define KPF_COMPOUND_TAIL      16
-#define KPF_HUGE               17
-#define KPF_UNEVICTABLE                18
-#define KPF_HWPOISON           19
-#define KPF_NOPAGE             20
-
-#define KPF_KSM                        21
-
-/* kernel hacking assistances
- * WARNING: subject to change, never rely on them!
- */
-#define KPF_RESERVED           32
-#define KPF_MLOCKED            33
-#define KPF_MAPPEDTODISK       34
-#define KPF_PRIVATE            35
-#define KPF_PRIVATE_2          36
-#define KPF_OWNER_PRIVATE      37
-#define KPF_ARCH               38
-#define KPF_UNCACHED           39
-
 static inline u64 kpf_copy_bit(u64 kflags, int ubit, int kbit)
 {
        return ((kflags >> kbit) & 1) << ubit;
 }
 
-static u64 get_uflags(struct page *page)
+u64 stable_page_flags(struct page *page)
 {
        u64 k;
        u64 u;
@@ -219,7 +180,7 @@ static ssize_t kpageflags_read(struct file *file, char __user *buf,
                else
                        ppage = NULL;
 
-               if (put_user(get_uflags(ppage), out)) {
+               if (put_user(stable_page_flags(ppage), out)) {
                        ret = -EFAULT;
                        break;
                }

diff --git a/include/linux/kernel-page-flags.h b/include/linux/kernel-page-flags.h
new file mode 100644 (file)
index 0000000..bd92a89
--- /dev/null
+++ b/include/linux/kernel-page-flags.h
@@ -0,0 +1,46 @@
+#ifndef LINUX_KERNEL_PAGE_FLAGS_H
+#define LINUX_KERNEL_PAGE_FLAGS_H
+
+/*
+ * Stable page flag bits exported to user space
+ */
+
+#define KPF_LOCKED             0
+#define KPF_ERROR              1
+#define KPF_REFERENCED         2
+#define KPF_UPTODATE           3
+#define KPF_DIRTY              4
+#define KPF_LRU                        5
+#define KPF_ACTIVE             6
+#define KPF_SLAB               7
+#define KPF_WRITEBACK          8
+#define KPF_RECLAIM            9
+#define KPF_BUDDY              10
+
+/* 11-20: new additions in 2.6.31 */
+#define KPF_MMAP               11
+#define KPF_ANON               12
+#define KPF_SWAPCACHE          13
+#define KPF_SWAPBACKED         14
+#define KPF_COMPOUND_HEAD      15
+#define KPF_COMPOUND_TAIL      16
+#define KPF_HUGE               17
+#define KPF_UNEVICTABLE                18
+#define KPF_HWPOISON           19
+#define KPF_NOPAGE             20
+
+#define KPF_KSM                        21
+
+/* kernel hacking assistances
+ * WARNING: subject to change, never rely on them!
+ */
+#define KPF_RESERVED           32
+#define KPF_MLOCKED            33
+#define KPF_MAPPEDTODISK       34
+#define KPF_PRIVATE            35
+#define KPF_PRIVATE_2          36
+#define KPF_OWNER_PRIVATE      37
+#define KPF_ARCH               38
+#define KPF_UNCACHED           39
+
+#endif /* LINUX_KERNEL_PAGE_FLAGS_H */

diff --git a/include/linux/page-flags.h b/include/linux/page-flags.h
index f9df6308af953ccf0de509531355af5d0fd5ce2f..feee2ba8d06a39e90e841289e8e83b9750ee871e 100644 (file)
--- a/include/linux/page-flags.h
+++ b/include/linux/page-flags.h
@@ -282,6 +282,8 @@ PAGEFLAG_FALSE(HWPoison)
 #define __PG_HWPOISON 0
 #endif
 
+u64 stable_page_flags(struct page *page);
+
 static inline int PageUptodate(struct page *page)
 {
        int ret = test_bit(PG_uptodate, &(page)->flags);