1 files changed, 30 insertions, 48 deletions

diff --git a/fs/proc/page.c b/fs/proc/page.c
index 2707c6c7a20..e647c55275d 100644
--- a/fs/proc/page.c
+++ b/fs/proc/page.c
@@ -2,11 +2,13 @@
 #include <linux/compiler.h>
 #include <linux/fs.h>
 #include <linux/init.h>
+#include <linux/ksm.h>
 #include <linux/mm.h>
 #include <linux/mmzone.h>
 #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"
 
@@ -38,7 +40,7 @@ static ssize_t kpagecount_read(struct file *file, char __user *buf,
 			ppage = pfn_to_page(pfn);
 		else
 			ppage = NULL;
-		if (!ppage)
+		if (!ppage || PageSlab(ppage))
 			pcount = 0;
 		else
 			pcount = page_mapcount(ppage);
@@ -70,49 +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_NOPAGE		20
-
-/* 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;
@@ -137,6 +102,8 @@ static u64 get_uflags(struct page *page)
 		u |= 1 << KPF_MMAP;
 	if (PageAnon(page))
 		u |= 1 << KPF_ANON;
+	if (PageKsm(page))
+		u |= 1 << KPF_KSM;
 
 	/*
 	 * compound pages: export both head/tail info
@@ -148,16 +115,27 @@ static u64 get_uflags(struct page *page)
 		u |= 1 << KPF_COMPOUND_TAIL;
 	if (PageHuge(page))
 		u |= 1 << KPF_HUGE;
-
-	u |= kpf_copy_bit(k, KPF_LOCKED,	PG_locked);
+	/*
+	 * PageTransCompound can be true for non-huge compound pages (slab
+	 * pages or pages allocated by drivers with __GFP_COMP) because it
+	 * just checks PG_head/PG_tail, so we need to check PageLRU/PageAnon
+	 * to make sure a given page is a thp, not a non-huge compound page.
+	 */
+	else if (PageTransCompound(page) && (PageLRU(compound_head(page)) ||
+					     PageAnon(compound_head(page))))
+		u |= 1 << KPF_THP;
 
 	/*
-	 * Caveats on high order pages:
-	 * PG_buddy will only be set on the head page; SLUB/SLQB do the same
-	 * for PG_slab; SLOB won't set PG_slab at all on compound pages.
+	 * Caveats on high order pages: page->_count will only be set
+	 * -1 on the head page; SLUB/SLQB do the same for PG_slab;
+	 * SLOB won't set PG_slab at all on compound pages.
 	 */
+	if (PageBuddy(page))
+		u |= 1 << KPF_BUDDY;
+
+	u |= kpf_copy_bit(k, KPF_LOCKED,	PG_locked);
+
 	u |= kpf_copy_bit(k, KPF_SLAB,		PG_slab);
-	u |= kpf_copy_bit(k, KPF_BUDDY,		PG_buddy);
 
 	u |= kpf_copy_bit(k, KPF_ERROR,		PG_error);
 	u |= kpf_copy_bit(k, KPF_DIRTY,		PG_dirty);
@@ -175,7 +153,11 @@ static u64 get_uflags(struct page *page)
 	u |= kpf_copy_bit(k, KPF_UNEVICTABLE,	PG_unevictable);
 	u |= kpf_copy_bit(k, KPF_MLOCKED,	PG_mlocked);
 
-#ifdef CONFIG_IA64_UNCACHED_ALLOCATOR
+#ifdef CONFIG_MEMORY_FAILURE
+	u |= kpf_copy_bit(k, KPF_HWPOISON,	PG_hwpoison);
+#endif
+
+#ifdef CONFIG_ARCH_USES_PG_UNCACHED
 	u |= kpf_copy_bit(k, KPF_UNCACHED,	PG_uncached);
 #endif
 
@@ -209,7 +191,7 @@ 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;
 		}
@@ -236,4 +218,4 @@ static int __init proc_page_init(void)
 	proc_create("kpageflags", S_IRUSR, NULL, &proc_kpageflags_operations);
 	return 0;
 }
-module_init(proc_page_init);
+fs_initcall(proc_page_init);