Commit 1a9b5b7f authored by Wu Fengguang's avatar Wu Fengguang Committed by Andi Kleen
Browse files

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: default avatarMatt Mackall <mpm@selenic.com>
Signed-off-by: default avatarAndi Kleen <ak@linux.intel.com>
CC: Nick Piggin <npiggin@suse.de>
CC: Christoph Lameter <cl@linux-foundation.org>
Signed-off-by: default avatarWu Fengguang <fengguang.wu@intel.com>
Signed-off-by: default avatarAndi Kleen <ak@linux.intel.com>
parent 31d3d348

fs/proc/page.c

+3 −42
Original line number Diff line number Diff line
@@ -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;

		}

include/linux/kernel-page-flags.h

0 → 100644
+46 −0
Original line number Diff line number Diff line 
#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 */

include/linux/page-flags.h

+2 −0
Original line number Diff line number Diff line
@@ -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);

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