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
  ...

8 files changed, 121 insertions, 9 deletions

diff --git a/include/linux/fs.h b/include/linux/fs.h
index 33ed6644abd0..78e95b8b66d4 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -595,6 +595,7 @@ struct address_space_operations {
         int (*launder_page) (struct page *);
         int (*is_partially_uptodate) (struct page *, read_descriptor_t *,
                                         unsigned long);
+        int (*error_remove_page)(struct address_space *, struct page *);
 };
 
 /*
diff --git a/include/linux/mm.h b/include/linux/mm.h
index 87218ae84e36..6953a5a53e44 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -695,11 +695,12 @@ static inline int page_mapped(struct page *page)
 #define VM_FAULT_SIGBUS 0x0002
 #define VM_FAULT_MAJOR  0x0004
 #define VM_FAULT_WRITE  0x0008  /* Special case for get_user_pages */
+#define VM_FAULT_HWPOISON 0x0010        /* Hit poisoned page */
 
 #define VM_FAULT_NOPAGE 0x0100  /* ->fault installed the pte, not return page */
 #define VM_FAULT_LOCKED 0x0200  /* ->fault locked the returned page */
 
-#define VM_FAULT_ERROR  (VM_FAULT_OOM | VM_FAULT_SIGBUS)
+#define VM_FAULT_ERROR  (VM_FAULT_OOM | VM_FAULT_SIGBUS | VM_FAULT_HWPOISON)
 
 /*
  * Can be called by the pagefault handler when it gets a VM_FAULT_OOM.
@@ -794,6 +795,11 @@ static inline void unmap_shared_mapping_range(struct address_space *mapping,
 extern int vmtruncate(struct inode * inode, loff_t offset);
 extern int vmtruncate_range(struct inode * inode, loff_t offset, loff_t end);
 
+int truncate_inode_page(struct address_space *mapping, struct page *page);
+int generic_error_remove_page(struct address_space *mapping, struct page *page);
+
+int invalidate_inode_page(struct page *page);
+
 #ifdef CONFIG_MMU
 extern int handle_mm_fault(struct mm_struct *mm, struct vm_area_struct *vma,
                         unsigned long address, unsigned int flags);
@@ -1308,5 +1314,12 @@ void vmemmap_populate_print_last(void);
 extern int account_locked_memory(struct mm_struct *mm, struct rlimit *rlim,
                                  size_t size);
 extern void refund_locked_memory(struct mm_struct *mm, size_t size);
+
+extern void memory_failure(unsigned long pfn, int trapno);
+extern int __memory_failure(unsigned long pfn, int trapno, int ref);
+extern int sysctl_memory_failure_early_kill;
+extern int sysctl_memory_failure_recovery;
+extern atomic_long_t mce_bad_pages;
+
 #endif /* __KERNEL__ */
 #endif /* _LINUX_MM_H */
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.
diff --git a/include/linux/prctl.h b/include/linux/prctl.h
index 07bff666e65b..931150566ade 100644
--- a/include/linux/prctl.h
+++ b/include/linux/prctl.h
@@ -88,4 +88,6 @@
 #define PR_TASK_PERF_EVENTS_DISABLE             31
 #define PR_TASK_PERF_EVENTS_ENABLE              32
 
+#define PR_MCE_KILL     33
+
 #endif /* _LINUX_PRCTL_H */
diff --git a/include/linux/rmap.h b/include/linux/rmap.h
index 477841d29fce..cb0ba7032609 100644
--- a/include/linux/rmap.h
+++ b/include/linux/rmap.h
@@ -81,7 +81,19 @@ static inline void page_dup_rmap(struct page *page)
  */
 int page_referenced(struct page *, int is_locked,
                         struct mem_cgroup *cnt, unsigned long *vm_flags);
-int try_to_unmap(struct page *, int ignore_refs);
+enum ttu_flags {
+        TTU_UNMAP = 0,                  /* unmap mode */
+        TTU_MIGRATION = 1,              /* migration mode */
+        TTU_MUNLOCK = 2,                /* munlock mode */
+        TTU_ACTION_MASK = 0xff,
+
+        TTU_IGNORE_MLOCK = (1 << 8),    /* ignore mlock */
+        TTU_IGNORE_ACCESS = (1 << 9),   /* don't age */
+        TTU_IGNORE_HWPOISON = (1 << 10),/* corrupted page is recoverable */
+};
+#define TTU_ACTION(x) ((x) & TTU_ACTION_MASK)
+
+int try_to_unmap(struct page *, enum ttu_flags flags);
 
 /*
  * Called from mm/filemap_xip.c to unmap empty zero page
@@ -108,6 +120,13 @@ int page_mkclean(struct page *);
  */
 int try_to_munlock(struct page *);
 
+/*
+ * Called by memory-failure.c to kill processes.
+ */
+struct anon_vma *page_lock_anon_vma(struct page *page);
+void page_unlock_anon_vma(struct anon_vma *anon_vma);
+int page_mapped_in_vma(struct page *page, struct vm_area_struct *vma);
+
 #else   /* !CONFIG_MMU */
 
 #define anon_vma_init()         do {} while (0)
diff --git a/include/linux/sched.h b/include/linux/sched.h
index 8a16f6d11dcd..75e6e60bf583 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -1734,6 +1734,7 @@ extern cputime_t task_gtime(struct task_struct *p);
 #define PF_EXITPIDONE   0x00000008      /* pi exit done on shut down */
 #define PF_VCPU         0x00000010      /* I'm a virtual CPU */
 #define PF_FORKNOEXEC   0x00000040      /* forked but didn't exec */
+#define PF_MCE_PROCESS  0x00000080      /* process policy on mce errors */
 #define PF_SUPERPRIV    0x00000100      /* used super-user privileges */
 #define PF_DUMPCORE     0x00000200      /* dumped core */
 #define PF_SIGNALED     0x00000400      /* killed by a signal */
@@ -1753,6 +1754,7 @@ extern cputime_t task_gtime(struct task_struct *p);
 #define PF_SPREAD_PAGE  0x01000000      /* Spread page cache over cpuset */
 #define PF_SPREAD_SLAB  0x02000000      /* Spread some slab caches over cpuset */
 #define PF_THREAD_BOUND 0x04000000      /* Thread bound to specific cpu */
+#define PF_MCE_EARLY    0x08000000      /* Early kill for mce process policy */
 #define PF_MEMPOLICY    0x10000000      /* Non-default NUMA mempolicy */
 #define PF_MUTEX_TESTER 0x20000000      /* Thread belongs to the rt mutex tester */
 #define PF_FREEZER_SKIP 0x40000000      /* Freezer should not count it as freezeable */
diff --git a/include/linux/swap.h b/include/linux/swap.h
index 82232dbea3f7..4ec90019c1a4 100644
--- a/include/linux/swap.h
+++ b/include/linux/swap.h
@@ -34,16 +34,38 @@ static inline int current_is_kswapd(void)
  * the type/offset into the pte as 5/27 as well.
  */
 #define MAX_SWAPFILES_SHIFT     5
-#ifndef CONFIG_MIGRATION
-#define MAX_SWAPFILES           (1 << MAX_SWAPFILES_SHIFT)
+
+/*
+ * Use some of the swap files numbers for other purposes. This
+ * is a convenient way to hook into the VM to trigger special
+ * actions on faults.
+ */
+
+/*
+ * NUMA node memory migration support
+ */
+#ifdef CONFIG_MIGRATION
+#define SWP_MIGRATION_NUM 2
+#define SWP_MIGRATION_READ      (MAX_SWAPFILES + SWP_HWPOISON_NUM)
+#define SWP_MIGRATION_WRITE     (MAX_SWAPFILES + SWP_HWPOISON_NUM + 1)
 #else
-/* Use last two entries for page migration swap entries */
-#define MAX_SWAPFILES           ((1 << MAX_SWAPFILES_SHIFT)-2)
-#define SWP_MIGRATION_READ      MAX_SWAPFILES
-#define SWP_MIGRATION_WRITE     (MAX_SWAPFILES + 1)
+#define SWP_MIGRATION_NUM 0
 #endif
 
 /*
+ * Handling of hardware poisoned pages with memory corruption.
+ */
+#ifdef CONFIG_MEMORY_FAILURE
+#define SWP_HWPOISON_NUM 1
+#define SWP_HWPOISON            MAX_SWAPFILES
+#else
+#define SWP_HWPOISON_NUM 0
+#endif
+
+#define MAX_SWAPFILES \
+        ((1 << MAX_SWAPFILES_SHIFT) - SWP_MIGRATION_NUM - SWP_HWPOISON_NUM)
+
+/*
  * Magic header for a swap area. The first part of the union is
  * what the swap magic looks like for the old (limited to 128MB)
  * swap area format, the second part of the union adds - in the
diff --git a/include/linux/swapops.h b/include/linux/swapops.h
index 6ec39ab27b4b..cd42e30b7c6e 100644
--- a/include/linux/swapops.h
+++ b/include/linux/swapops.h
@@ -131,3 +131,41 @@ static inline int is_write_migration_entry(swp_entry_t entry)
 
 #endif
 
+#ifdef CONFIG_MEMORY_FAILURE
+/*
+ * Support for hardware poisoned pages
+ */
+static inline swp_entry_t make_hwpoison_entry(struct page *page)
+{
+        BUG_ON(!PageLocked(page));
+        return swp_entry(SWP_HWPOISON, page_to_pfn(page));
+}
+
+static inline int is_hwpoison_entry(swp_entry_t entry)
+{
+        return swp_type(entry) == SWP_HWPOISON;
+}
+#else
+
+static inline swp_entry_t make_hwpoison_entry(struct page *page)
+{
+        return swp_entry(0, 0);
+}
+
+static inline int is_hwpoison_entry(swp_entry_t swp)
+{
+        return 0;
+}
+#endif
+
+#if defined(CONFIG_MEMORY_FAILURE) || defined(CONFIG_MIGRATION)
+static inline int non_swap_entry(swp_entry_t entry)
+{
+        return swp_type(entry) >= MAX_SWAPFILES;
+}
+#else
+static inline int non_swap_entry(swp_entry_t entry)
+{
+        return 0;
+}
+#endif