pagemap: export KPF_HWPOISON

This flag indicates a hardware detected memory corruption on the page.
Any future access of the page data may bring down the machine.

Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
Cc: Andi Kleen <andi@firstfloor.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

3 files changed, 11 insertions, 0 deletions

diff --git a/Documentation/vm/page-types.c b/Documentation/vm/page-types.c
index fa1a30d9e9d5..87f57228f56e 100644
--- a/Documentation/vm/page-types.c
+++ b/Documentation/vm/page-types.c
@@ -69,6 +69,7 @@
 #define KPF_COMPOUND_TAIL       16
 #define KPF_HUGE                17
 #define KPF_UNEVICTABLE         18
+#define KPF_HWPOISON            19
 #define KPF_NOPAGE              20
 
 /* [32-] kernel hacking assistances */
@@ -116,6 +117,7 @@ static char *page_flag_names[] = {
         [KPF_COMPOUND_TAIL]     = "T:compound_tail",
         [KPF_HUGE]              = "G:huge",
         [KPF_UNEVICTABLE]       = "u:unevictable",
+        [KPF_HWPOISON]          = "X:hwpoison",
         [KPF_NOPAGE]            = "n:nopage",
 
         [KPF_RESERVED]          = "r:reserved",
diff --git a/Documentation/vm/pagemap.txt b/Documentation/vm/pagemap.txt
index 600a304a828c..2fdd84a19109 100644
--- a/Documentation/vm/pagemap.txt
+++ b/Documentation/vm/pagemap.txt
@@ -57,6 +57,7 @@ There are three components to pagemap:
     16. COMPOUND_TAIL
     16. HUGE
     18. UNEVICTABLE
+    19. HWPOISON
     20. NOPAGE
 
 Short descriptions to the page flags:
@@ -86,6 +87,9 @@ Short descriptions to the page flags:
 17. HUGE
     this is an integral part of a HugeTLB page
 
+19. HWPOISON
+    hardware detected memory corruption on this page: don't touch the data!
+
 20. NOPAGE
     no page frame exists at the requested address
 
diff --git a/fs/proc/page.c b/fs/proc/page.c
index 2281c2cbfe2b..5033ce0d254b 100644
--- a/fs/proc/page.c
+++ b/fs/proc/page.c
@@ -94,6 +94,7 @@ static const struct file_operations proc_kpagecount_operations = {
 #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
@@ -180,6 +181,10 @@ 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_MEMORY_FAILURE
+        u |= kpf_copy_bit(k, KPF_HWPOISON,      PG_hwpoison);
+#endif
+
 #ifdef CONFIG_IA64_UNCACHED_ALLOCATOR
         u |= kpf_copy_bit(k, KPF_UNCACHED,      PG_uncached);
 #endif