Merge branch 'akpm' (patches from Andrew)

Merge fixes from Andrew Morton:
 "20 fixes"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>:
  Documentation/sysctl/vm.txt: update numa_zonelist_order description
  lib/stackdepot.c: allow the stack trace hash to be zero
  rapidio: fix potential NULL pointer dereference
  mm/memory-failure: fix race with compound page split/merge
  ocfs2/dlm: return zero if deref_done message is successfully handled
  Ananth has moved
  kcov: don't profile branches in kcov
  kcov: don't trace the code coverage code
  mm: wake kcompactd before kswapd's short sleep
  .mailmap: add Frank Rowand
  mm/hwpoison: fix wrong num_poisoned_pages accounting
  mm: call swap_slot_free_notify() with page lock held
  mm: vmscan: reclaim highmem zone if buffer_heads is over limit
  numa: fix /proc/<pid>/numa_maps for THP
  mm/huge_memory: replace VM_NO_THP VM_BUG_ON with actual VMA check
  mailmap: fix Krzysztof Kozlowski's misspelled name
  thp: keep huge zero page pinned until tlb flush
  mm: exclude HugeTLB pages from THP page_mapped() logic
  kexec: export OFFSET(page.compound_head) to find out compound tail page
  kexec: update VMCOREINFO for compound_order/dtor

18 files changed, 151 insertions, 47 deletions

diff --git a/.mailmap b/.mailmap
index 90c0aefc276d..c156a8b4d845 100644
--- a/.mailmap
+++ b/.mailmap
@@ -48,6 +48,9 @@ Felix Kuhling <fxkuehl@gmx.de>
 Felix Moeller <felix@derklecks.de>
 Filipe Lautert <filipe@icewall.org>
 Franck Bui-Huu <vagabon.xyz@gmail.com>
+Frank Rowand <frowand.list@gmail.com> <frowand@mvista.com>
+Frank Rowand <frowand.list@gmail.com> <frank.rowand@am.sony.com>
+Frank Rowand <frowand.list@gmail.com> <frank.rowand@sonymobile.com>
 Frank Zago <fzago@systemfabricworks.com>
 Greg Kroah-Hartman <greg@echidna.(none)>
 Greg Kroah-Hartman <gregkh@suse.de>
@@ -79,6 +82,7 @@ Kay Sievers <kay.sievers@vrfy.org>
 Kenneth W Chen <kenneth.w.chen@intel.com>
 Konstantin Khlebnikov <koct9i@gmail.com> <k.khlebnikov@samsung.com>
 Koushik <raghavendra.koushik@neterion.com>
+Krzysztof Kozlowski <krzk@kernel.org> <k.kozlowski.k@gmail.com>
 Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
 Leonid I Ananiev <leonid.i.ananiev@intel.com>
 Linas Vepstas <linas@austin.ibm.com>
diff --git a/Documentation/sysctl/vm.txt b/Documentation/sysctl/vm.txt
index cb0368459da3..34a5fece3121 100644
--- a/Documentation/sysctl/vm.txt
+++ b/Documentation/sysctl/vm.txt
@@ -581,15 +581,16 @@ Specify "[Nn]ode" for node order
 "Zone Order" orders the zonelists by zone type, then by node within each
 zone.  Specify "[Zz]one" for zone order.
 
-Specify "[Dd]efault" to request automatic configuration.  Autoconfiguration
-will select "node" order in following case.
-(1) if the DMA zone does not exist or
-(2) if the DMA zone comprises greater than 50% of the available memory or
-(3) if any node's DMA zone comprises greater than 70% of its local memory and
-    the amount of local memory is big enough.
-
-Otherwise, "zone" order will be selected. Default order is recommended unless
-this is causing problems for your system/application.
+Specify "[Dd]efault" to request automatic configuration.
+
+On 32-bit, the Normal zone needs to be preserved for allocations accessible
+by the kernel, so "zone" order will be selected.
+
+On 64-bit, devices that require DMA32/DMA are relatively rare, so "node"
+order will be selected.
+
+Default order is recommended unless this is causing problems for your
+system/application.
 
 ==============================================================
 
diff --git a/MAINTAINERS b/MAINTAINERS
index 849133608da7..7f72d54f065d 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -6400,7 +6400,7 @@ F:	mm/kmemleak.c
 F:      mm/kmemleak-test.c
 
 KPROBES
-M:      Ananth N Mavinakayanahalli <ananth@in.ibm.com>
+M:      Ananth N Mavinakayanahalli <ananth@linux.vnet.ibm.com>
 M:      Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
 M:      "David S. Miller" <davem@davemloft.net>
 M:      Masami Hiramatsu <mhiramat@kernel.org>
diff --git a/drivers/rapidio/devices/rio_mport_cdev.c b/drivers/rapidio/devices/rio_mport_cdev.c
index 5d4d91846357..96168b819044 100644
--- a/drivers/rapidio/devices/rio_mport_cdev.c
+++ b/drivers/rapidio/devices/rio_mport_cdev.c
@@ -2669,9 +2669,9 @@ static int __init mport_init(void)
 
         /* Create device class needed by udev */
         dev_class = class_create(THIS_MODULE, DRV_NAME);
-        if (!dev_class) {
+        if (IS_ERR(dev_class)) {
                 rmcd_error("Unable to create " DRV_NAME " class");
-                return -EINVAL;
+                return PTR_ERR(dev_class);
         }
 
         ret = alloc_chrdev_region(&dev_number, 0, RIO_MAX_MPORTS, DRV_NAME);
diff --git a/fs/ocfs2/dlm/dlmmaster.c b/fs/ocfs2/dlm/dlmmaster.c
index 9aed6e202201..13719d3f35f8 100644
--- a/fs/ocfs2/dlm/dlmmaster.c
+++ b/fs/ocfs2/dlm/dlmmaster.c
@@ -2455,6 +2455,8 @@ int dlm_deref_lockres_done_handler(struct o2net_msg *msg, u32 len, void *data,
 
         spin_unlock(&dlm->spinlock);
 
+        ret = 0;
+
 done:
         dlm_put(dlm);
         return ret;
diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c
index 229cb546bee0..541583510cfb 100644
--- a/fs/proc/task_mmu.c
+++ b/fs/proc/task_mmu.c
@@ -1518,6 +1518,32 @@ static struct page *can_gather_numa_stats(pte_t pte, struct vm_area_struct *vma,
         return page;
 }
 
+#ifdef CONFIG_TRANSPARENT_HUGEPAGE
+static struct page *can_gather_numa_stats_pmd(pmd_t pmd,
+                                              struct vm_area_struct *vma,
+                                              unsigned long addr)
+{
+        struct page *page;
+        int nid;
+
+        if (!pmd_present(pmd))
+                return NULL;
+
+        page = vm_normal_page_pmd(vma, addr, pmd);
+        if (!page)
+                return NULL;
+
+        if (PageReserved(page))
+                return NULL;
+
+        nid = page_to_nid(page);
+        if (!node_isset(nid, node_states[N_MEMORY]))
+                return NULL;
+
+        return page;
+}
+#endif
+
 static int gather_pte_stats(pmd_t *pmd, unsigned long addr,
                 unsigned long end, struct mm_walk *walk)
 {
@@ -1527,14 +1553,14 @@ static int gather_pte_stats(pmd_t *pmd, unsigned long addr,
         pte_t *orig_pte;
         pte_t *pte;
 
+#ifdef CONFIG_TRANSPARENT_HUGEPAGE
         ptl = pmd_trans_huge_lock(pmd, vma);
         if (ptl) {
-                pte_t huge_pte = *(pte_t *)pmd;
                 struct page *page;
 
-                page = can_gather_numa_stats(huge_pte, vma, addr);
+                page = can_gather_numa_stats_pmd(*pmd, vma, addr);
                 if (page)
-                        gather_stats(page, md, pte_dirty(huge_pte),
+                        gather_stats(page, md, pmd_dirty(*pmd),
                                      HPAGE_PMD_SIZE/PAGE_SIZE);
                 spin_unlock(ptl);
                 return 0;
@@ -1542,6 +1568,7 @@ static int gather_pte_stats(pmd_t *pmd, unsigned long addr,
 
         if (pmd_trans_unstable(pmd))
                 return 0;
+#endif
         orig_pte = pte = pte_offset_map_lock(walk->mm, pmd, addr, &ptl);
         do {
                 struct page *page = can_gather_numa_stats(*pte, vma, addr);
diff --git a/include/linux/huge_mm.h b/include/linux/huge_mm.h
index 7008623e24b1..d7b9e5346fba 100644
--- a/include/linux/huge_mm.h
+++ b/include/linux/huge_mm.h
@@ -152,6 +152,7 @@ static inline bool is_huge_zero_pmd(pmd_t pmd)
 }
 
 struct page *get_huge_zero_page(void);
+void put_huge_zero_page(void);
 
 #else /* CONFIG_TRANSPARENT_HUGEPAGE */
 #define HPAGE_PMD_SHIFT ({ BUILD_BUG(); 0; })
@@ -208,6 +209,10 @@ static inline bool is_huge_zero_page(struct page *page)
         return false;
 }
 
+static inline void put_huge_zero_page(void)
+{
+        BUILD_BUG();
+}
 
 static inline struct page *follow_devmap_pmd(struct vm_area_struct *vma,
                 unsigned long addr, pmd_t *pmd, int flags)
diff --git a/include/linux/mm.h b/include/linux/mm.h
index a55e5be0894f..864d7221de84 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -1031,6 +1031,8 @@ static inline bool page_mapped(struct page *page)
         page = compound_head(page);
         if (atomic_read(compound_mapcount_ptr(page)) >= 0)
                 return true;
+        if (PageHuge(page))
+                return false;
         for (i = 0; i < hpage_nr_pages(page); i++) {
                 if (atomic_read(&page[i]._mapcount) >= 0)
                         return true;
@@ -1138,6 +1140,8 @@ struct zap_details {
 
 struct page *vm_normal_page(struct vm_area_struct *vma, unsigned long addr,
                 pte_t pte);
+struct page *vm_normal_page_pmd(struct vm_area_struct *vma, unsigned long addr,
+                                pmd_t pmd);
 
 int zap_vma_ptes(struct vm_area_struct *vma, unsigned long address,
                 unsigned long size);
diff --git a/kernel/kcov.c b/kernel/kcov.c
index 3efbee0834a8..a02f2dddd1d7 100644
--- a/kernel/kcov.c
+++ b/kernel/kcov.c
@@ -1,5 +1,6 @@
 #define pr_fmt(fmt) "kcov: " fmt
 
+#define DISABLE_BRANCH_PROFILING
 #include <linux/compiler.h>
 #include <linux/types.h>
 #include <linux/file.h>
@@ -43,7 +44,7 @@ struct kcov {
  * Entry point from instrumented code.
  * This is called once per basic-block/edge.
  */
-void __sanitizer_cov_trace_pc(void)
+void notrace __sanitizer_cov_trace_pc(void)
 {
         struct task_struct *t;
         enum kcov_mode mode;
diff --git a/kernel/kexec_core.c b/kernel/kexec_core.c
index 8d34308ea449..1391d3ee3b86 100644
--- a/kernel/kexec_core.c
+++ b/kernel/kexec_core.c
@@ -1415,6 +1415,9 @@ static int __init crash_save_vmcoreinfo_init(void)
         VMCOREINFO_OFFSET(page, lru);
         VMCOREINFO_OFFSET(page, _mapcount);
         VMCOREINFO_OFFSET(page, private);
+        VMCOREINFO_OFFSET(page, compound_dtor);
+        VMCOREINFO_OFFSET(page, compound_order);
+        VMCOREINFO_OFFSET(page, compound_head);
         VMCOREINFO_OFFSET(pglist_data, node_zones);
         VMCOREINFO_OFFSET(pglist_data, nr_zones);
 #ifdef CONFIG_FLAT_NODE_MEM_MAP
@@ -1447,8 +1450,8 @@ static int __init crash_save_vmcoreinfo_init(void)
 #ifdef CONFIG_X86
         VMCOREINFO_NUMBER(KERNEL_IMAGE_SIZE);
 #endif
-#ifdef CONFIG_HUGETLBFS
-        VMCOREINFO_SYMBOL(free_huge_page);
+#ifdef CONFIG_HUGETLB_PAGE
+        VMCOREINFO_NUMBER(HUGETLB_PAGE_DTOR);
 #endif
 
         arch_crash_save_vmcoreinfo();
diff --git a/lib/stackdepot.c b/lib/stackdepot.c
index 654c9d87e83a..9e0b0315a724 100644
--- a/lib/stackdepot.c
+++ b/lib/stackdepot.c
@@ -210,10 +210,6 @@ depot_stack_handle_t depot_save_stack(struct stack_trace *trace,
                 goto fast_exit;
 
         hash = hash_stack(trace->entries, trace->nr_entries);
-        /* Bad luck, we won't store this stack. */
-        if (hash == 0)
-                goto exit;
-
         bucket = &stack_table[hash & STACK_HASH_MASK];
 
         /*
diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index 86f9f8b82f8e..df67b53ae3c5 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -232,7 +232,7 @@ retry:
         return READ_ONCE(huge_zero_page);
 }
 
-static void put_huge_zero_page(void)
+void put_huge_zero_page(void)
 {
         /*
          * Counter should never go to zero here. Only shrinker can put
@@ -1684,12 +1684,12 @@ int zap_huge_pmd(struct mmu_gather *tlb, struct vm_area_struct *vma,
         if (vma_is_dax(vma)) {
                 spin_unlock(ptl);
                 if (is_huge_zero_pmd(orig_pmd))
-                        put_huge_zero_page();
+                        tlb_remove_page(tlb, pmd_page(orig_pmd));
         } else if (is_huge_zero_pmd(orig_pmd)) {
                 pte_free(tlb->mm, pgtable_trans_huge_withdraw(tlb->mm, pmd));
                 atomic_long_dec(&tlb->mm->nr_ptes);
                 spin_unlock(ptl);
-                put_huge_zero_page();
+                tlb_remove_page(tlb, pmd_page(orig_pmd));
         } else {
                 struct page *page = pmd_page(orig_pmd);
                 page_remove_rmap(page, true);
@@ -1960,10 +1960,9 @@ int khugepaged_enter_vma_merge(struct vm_area_struct *vma,
                  * page fault if needed.
                  */
                 return 0;
-        if (vma->vm_ops)
+        if (vma->vm_ops || (vm_flags & VM_NO_THP))
                 /* khugepaged not yet working on file or special mappings */
                 return 0;
-        VM_BUG_ON_VMA(vm_flags & VM_NO_THP, vma);
         hstart = (vma->vm_start + ~HPAGE_PMD_MASK) & HPAGE_PMD_MASK;
         hend = vma->vm_end & HPAGE_PMD_MASK;
         if (hstart < hend)
@@ -2352,8 +2351,7 @@ static bool hugepage_vma_check(struct vm_area_struct *vma)
                 return false;
         if (is_vma_temporary_stack(vma))
                 return false;
-        VM_BUG_ON_VMA(vma->vm_flags & VM_NO_THP, vma);
-        return true;
+        return !(vma->vm_flags & VM_NO_THP);
 }
 
 static void collapse_huge_page(struct mm_struct *mm,
diff --git a/mm/memory-failure.c b/mm/memory-failure.c
index 78f5f2641b91..ca5acee53b7a 100644
--- a/mm/memory-failure.c
+++ b/mm/memory-failure.c
@@ -888,7 +888,15 @@ int get_hwpoison_page(struct page *page)
                 }
         }
 
-        return get_page_unless_zero(head);
+        if (get_page_unless_zero(head)) {
+                if (head == compound_head(page))
+                        return 1;
+
+                pr_info("MCE: %#lx cannot catch tail\n", page_to_pfn(page));
+                put_page(head);
+        }
+
+        return 0;
 }
 EXPORT_SYMBOL_GPL(get_hwpoison_page);
 
diff --git a/mm/memory.c b/mm/memory.c
index 93897f23cc11..305537fc8640 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -789,6 +789,46 @@ out:
         return pfn_to_page(pfn);
 }
 
+#ifdef CONFIG_TRANSPARENT_HUGEPAGE
+struct page *vm_normal_page_pmd(struct vm_area_struct *vma, unsigned long addr,
+                                pmd_t pmd)
+{
+        unsigned long pfn = pmd_pfn(pmd);
+
+        /*
+         * There is no pmd_special() but there may be special pmds, e.g.
+         * in a direct-access (dax) mapping, so let's just replicate the
+         * !HAVE_PTE_SPECIAL case from vm_normal_page() here.
+         */
+        if (unlikely(vma->vm_flags & (VM_PFNMAP|VM_MIXEDMAP))) {
+                if (vma->vm_flags & VM_MIXEDMAP) {
+                        if (!pfn_valid(pfn))
+                                return NULL;
+                        goto out;
+                } else {
+                        unsigned long off;
+                        off = (addr - vma->vm_start) >> PAGE_SHIFT;
+                        if (pfn == vma->vm_pgoff + off)
+                                return NULL;
+                        if (!is_cow_mapping(vma->vm_flags))
+                                return NULL;
+                }
+        }
+
+        if (is_zero_pfn(pfn))
+                return NULL;
+        if (unlikely(pfn > highest_memmap_pfn))
+                return NULL;
+
+        /*
+         * NOTE! We still have PageReserved() pages in the page tables.
+         * eg. VDSO mappings can cause them to exist.
+         */
+out:
+        return pfn_to_page(pfn);
+}
+#endif
+
 /*
  * copy one vm_area from one task to the other. Assumes the page tables
  * already present in the new task to be cleared in the whole range
diff --git a/mm/migrate.c b/mm/migrate.c
index 6c822a7b27e0..f9dfb18a4eba 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -975,7 +975,13 @@ out:
                 dec_zone_page_state(page, NR_ISOLATED_ANON +
                                 page_is_file_cache(page));
                 /* Soft-offlined page shouldn't go through lru cache list */
-                if (reason == MR_MEMORY_FAILURE) {
+                if (reason == MR_MEMORY_FAILURE && rc == MIGRATEPAGE_SUCCESS) {
+                        /*
+                         * With this release, we free successfully migrated
+                         * page and set PG_HWPoison on just freed page
+                         * intentionally. Although it's rather weird, it's how
+                         * HWPoison flag works at the moment.
+                         */
                         put_page(page);
                         if (!test_set_page_hwpoison(page))
                                 num_poisoned_pages_inc();
diff --git a/mm/page_io.c b/mm/page_io.c
index cd92e3d67a32..985f23cfa79b 100644
--- a/mm/page_io.c
+++ b/mm/page_io.c
@@ -353,7 +353,11 @@ int swap_readpage(struct page *page)
 
         ret = bdev_read_page(sis->bdev, swap_page_sector(page), page);
         if (!ret) {
-                swap_slot_free_notify(page);
+                if (trylock_page(page)) {
+                        swap_slot_free_notify(page);
+                        unlock_page(page);
+                }
+
                 count_vm_event(PSWPIN);
                 return 0;
         }
diff --git a/mm/swap.c b/mm/swap.c
index a0bc206b4ac6..03aacbcb013f 100644
--- a/mm/swap.c
+++ b/mm/swap.c
@@ -728,6 +728,11 @@ void release_pages(struct page **pages, int nr, bool cold)
                         zone = NULL;
                 }
 
+                if (is_huge_zero_page(page)) {
+                        put_huge_zero_page();
+                        continue;
+                }
+
                 page = compound_head(page);
                 if (!put_page_testzero(page))
                         continue;
diff --git a/mm/vmscan.c b/mm/vmscan.c
index b934223eaa45..142cb61f4822 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -2553,7 +2553,7 @@ static bool shrink_zones(struct zonelist *zonelist, struct scan_control *sc)
                 sc->gfp_mask |= __GFP_HIGHMEM;
 
         for_each_zone_zonelist_nodemask(zone, z, zonelist,
-                                        requested_highidx, sc->nodemask) {
+                                        gfp_zone(sc->gfp_mask), sc->nodemask) {
                 enum zone_type classzone_idx;
 
                 if (!populated_zone(zone))
@@ -3318,6 +3318,20 @@ static void kswapd_try_to_sleep(pg_data_t *pgdat, int order,
         /* Try to sleep for a short interval */
         if (prepare_kswapd_sleep(pgdat, order, remaining,
                                                 balanced_classzone_idx)) {
+                /*
+                 * Compaction records what page blocks it recently failed to
+                 * isolate pages from and skips them in the future scanning.
+                 * When kswapd is going to sleep, it is reasonable to assume
+                 * that pages and compaction may succeed so reset the cache.
+                 */
+                reset_isolation_suitable(pgdat);
+
+                /*
+                 * We have freed the memory, now we should compact it to make
+                 * allocation of the requested order possible.
+                 */
+                wakeup_kcompactd(pgdat, order, classzone_idx);
+
                 remaining = schedule_timeout(HZ/10);
                 finish_wait(&pgdat->kswapd_wait, &wait);
                 prepare_to_wait(&pgdat->kswapd_wait, &wait, TASK_INTERRUPTIBLE);
@@ -3341,20 +3355,6 @@ static void kswapd_try_to_sleep(pg_data_t *pgdat, int order,
                  */
                 set_pgdat_percpu_threshold(pgdat, calculate_normal_threshold);
 
-                /*
-                 * Compaction records what page blocks it recently failed to
-                 * isolate pages from and skips them in the future scanning.
-                 * When kswapd is going to sleep, it is reasonable to assume
-                 * that pages and compaction may succeed so reset the cache.
-                 */
-                reset_isolation_suitable(pgdat);
-
-                /*
-                 * We have freed the memory, now we should compact it to make
-                 * allocation of the requested order possible.
-                 */
-                wakeup_kcompactd(pgdat, order, classzone_idx);
-
                 if (!kthread_should_stop())
                         schedule();