Merge branch 'hwpoison' of git://git.kernel.org/pub/scm/linux/kernel/git/ak/linux-mce-2.6

* 'hwpoison' of git://git.kernel.org/pub/scm/linux/kernel/git/ak/linux-mce-2.6: (21 commits)
  HWPOISON: Enable error_remove_page on btrfs
  HWPOISON: Add simple debugfs interface to inject hwpoison on arbitary PFNs
  HWPOISON: Add madvise() based injector for hardware poisoned pages v4
  HWPOISON: Enable error_remove_page for NFS
  HWPOISON: Enable .remove_error_page for migration aware file systems
  HWPOISON: The high level memory error handler in the VM v7
  HWPOISON: Add PR_MCE_KILL prctl to control early kill behaviour per process
  HWPOISON: shmem: call set_page_dirty() with locked page
  HWPOISON: Define a new error_remove_page address space op for async truncation
  HWPOISON: Add invalidate_inode_page
  HWPOISON: Refactor truncate to allow direct truncating of page v2
  HWPOISON: check and isolate corrupted free pages v2
  HWPOISON: Handle hardware poisoned pages in try_to_unmap
  HWPOISON: Use bitmask/action code for try_to_unmap behaviour
  HWPOISON: x86: Add VM_FAULT_HWPOISON handling to x86 page fault handler v2
  HWPOISON: Add poison check to page fault handling
  HWPOISON: Add basic support for poisoned pages in fault handler v3
  HWPOISON: Add new SIGBUS error codes for hardware poison signals
  HWPOISON: Add support for poison swap entries v2
  HWPOISON: Export some rmap vma locking to outside world
  ...

1 files changed, 16 insertions, 1 deletions

diff --git a/include/linux/page-flags.h b/include/linux/page-flags.h
index 13de789f0a5c..6b202b173955 100644
--- a/include/linux/page-flags.h
+++ b/include/linux/page-flags.h
@@ -51,6 +51,9 @@
  * PG_buddy is set to indicate that the page is free and in the buddy system
  * (see mm/page_alloc.c).
  *
+ * PG_hwpoison indicates that a page got corrupted in hardware and contains
+ * data with incorrect ECC bits that triggered a machine check. Accessing is
+ * not safe since it may cause another machine check. Don't touch!
  */
 
 /*
@@ -102,6 +105,9 @@ enum pageflags {
 #ifdef CONFIG_ARCH_USES_PG_UNCACHED
         PG_uncached,            /* Page has been mapped as uncached */
 #endif
+#ifdef CONFIG_MEMORY_FAILURE
+        PG_hwpoison,            /* hardware poisoned page. Don't touch */
+#endif
         __NR_PAGEFLAGS,
 
         /* Filesystems */
@@ -269,6 +275,15 @@ PAGEFLAG(Uncached, uncached)
 PAGEFLAG_FALSE(Uncached)
 #endif
 
+#ifdef CONFIG_MEMORY_FAILURE
+PAGEFLAG(HWPoison, hwpoison)
+TESTSETFLAG(HWPoison, hwpoison)
+#define __PG_HWPOISON (1UL << PG_hwpoison)
+#else
+PAGEFLAG_FALSE(HWPoison)
+#define __PG_HWPOISON 0
+#endif
+
 static inline int PageUptodate(struct page *page)
 {
         int ret = test_bit(PG_uptodate, &(page)->flags);
@@ -393,7 +408,7 @@ static inline void __ClearPageTail(struct page *page)
          1 << PG_private | 1 << PG_private_2 | \
          1 << PG_buddy   | 1 << PG_writeback | 1 << PG_reserved | \
          1 << PG_slab    | 1 << PG_swapcache | 1 << PG_active | \
-         1 << PG_unevictable | __PG_MLOCKED)
+         1 << PG_unevictable | __PG_MLOCKED | __PG_HWPOISON)
 
 /*
  * Flags checked when a page is prepped for return by the page allocator.