Merge branch 'akpm' (patches from Andrew)

Merge misc fixes from Andrew Morton:
 "13 fixes"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>:
  memcg: disable hierarchy support if bound to the legacy cgroup hierarchy
  mm: reorder can_do_mlock to fix audit denial
  kasan, module: move MODULE_ALIGN macro into <linux/moduleloader.h>
  kasan, module, vmalloc: rework shadow allocation for modules
  fanotify: fix event filtering with FAN_ONDIR set
  mm/nommu.c: export symbol max_mapnr
  arch/c6x/include/asm/pgtable.h: define dummy pgprot_writecombine for !MMU
  nilfs2: fix deadlock of segment constructor during recovery
  mm: cma: fix CMA aligned offset calculation
  mm, hugetlb: close race when setting PageTail for gigantic pages
  mm, oom: do not fail __GFP_NOFAIL allocation if oom killer is disabled
  drivers/rtc/rtc-s3c.c: add .needs_src_clk to s3c6410 RTC data
  ocfs2: make append_dio an incompat feature

8 files changed, 30 insertions, 13 deletions

diff --git a/mm/cma.c b/mm/cma.c
index 75016fd1de90..68ecb7a42983 100644
--- a/mm/cma.c
+++ b/mm/cma.c
@@ -64,15 +64,17 @@ static unsigned long cma_bitmap_aligned_mask(struct cma *cma, int align_order)
         return (1UL << (align_order - cma->order_per_bit)) - 1;
 }
 
+/*
+ * Find a PFN aligned to the specified order and return an offset represented in
+ * order_per_bits.
+ */
 static unsigned long cma_bitmap_aligned_offset(struct cma *cma, int align_order)
 {
-        unsigned int alignment;
-
         if (align_order <= cma->order_per_bit)
                 return 0;
-        alignment = 1UL << (align_order - cma->order_per_bit);
-        return ALIGN(cma->base_pfn, alignment) -
-                (cma->base_pfn >> cma->order_per_bit);
+
+        return (ALIGN(cma->base_pfn, (1UL << align_order))
+                - cma->base_pfn) >> cma->order_per_bit;
 }
 
 static unsigned long cma_bitmap_maxno(struct cma *cma)
diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 0a9ac6c26832..c41b2a0ee273 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -917,7 +917,6 @@ static void prep_compound_gigantic_page(struct page *page, unsigned long order)
         __SetPageHead(page);
         __ClearPageReserved(page);
         for (i = 1; i < nr_pages; i++, p = mem_map_next(p, page, i)) {
-                __SetPageTail(p);
                 /*
                  * For gigantic hugepages allocated through bootmem at
                  * boot, it's safer to be consistent with the not-gigantic
@@ -933,6 +932,9 @@ static void prep_compound_gigantic_page(struct page *page, unsigned long order)
                 __ClearPageReserved(p);
                 set_page_count(p, 0);
                 p->first_page = page;
+                /* Make sure p->first_page is always valid for PageTail() */
+                smp_wmb();
+                __SetPageTail(p);
         }
 }
 
diff --git a/mm/kasan/kasan.c b/mm/kasan/kasan.c
index 78fee632a7ee..936d81661c47 100644
--- a/mm/kasan/kasan.c
+++ b/mm/kasan/kasan.c
@@ -29,6 +29,7 @@
 #include <linux/stacktrace.h>
 #include <linux/string.h>
 #include <linux/types.h>
+#include <linux/vmalloc.h>
 #include <linux/kasan.h>
 
 #include "kasan.h"
@@ -414,12 +415,19 @@ int kasan_module_alloc(void *addr, size_t size)
                         GFP_KERNEL | __GFP_HIGHMEM | __GFP_ZERO,
                         PAGE_KERNEL, VM_NO_GUARD, NUMA_NO_NODE,
                         __builtin_return_address(0));
-        return ret ? 0 : -ENOMEM;
+
+        if (ret) {
+                find_vm_area(addr)->flags |= VM_KASAN;
+                return 0;
+        }
+
+        return -ENOMEM;
 }
 
-void kasan_module_free(void *addr)
+void kasan_free_shadow(const struct vm_struct *vm)
 {
-        vfree(kasan_mem_to_shadow(addr));
+        if (vm->flags & VM_KASAN)
+                vfree(kasan_mem_to_shadow(vm->addr));
 }
 
 static void register_global(struct kasan_global *global)
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 9fe07692eaad..b34ef4a32a3b 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -5232,7 +5232,9 @@ static void mem_cgroup_bind(struct cgroup_subsys_state *root_css)
          * on for the root memcg is enough.
          */
         if (cgroup_on_dfl(root_css->cgroup))
-                mem_cgroup_from_css(root_css)->use_hierarchy = true;
+                root_mem_cgroup->use_hierarchy = true;
+        else
+                root_mem_cgroup->use_hierarchy = false;
 }
 
 static u64 memory_current_read(struct cgroup_subsys_state *css,
diff --git a/mm/mlock.c b/mm/mlock.c
index 73cf0987088c..8a54cd214925 100644
--- a/mm/mlock.c
+++ b/mm/mlock.c
@@ -26,10 +26,10 @@
 
 int can_do_mlock(void)
 {
-        if (capable(CAP_IPC_LOCK))
-                return 1;
         if (rlimit(RLIMIT_MEMLOCK) != 0)
                 return 1;
+        if (capable(CAP_IPC_LOCK))
+                return 1;
         return 0;
 }
 EXPORT_SYMBOL(can_do_mlock);
diff --git a/mm/nommu.c b/mm/nommu.c
index 3e67e7538ecf..3fba2dc97c44 100644
--- a/mm/nommu.c
+++ b/mm/nommu.c
@@ -62,6 +62,7 @@ void *high_memory;
 EXPORT_SYMBOL(high_memory);
 struct page *mem_map;
 unsigned long max_mapnr;
+EXPORT_SYMBOL(max_mapnr);
 unsigned long highest_memmap_pfn;
 struct percpu_counter vm_committed_as;
 int sysctl_overcommit_memory = OVERCOMMIT_GUESS; /* heuristic overcommit */
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 7abfa70cdc1a..40e29429e7b0 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -2373,7 +2373,8 @@ __alloc_pages_may_oom(gfp_t gfp_mask, unsigned int order,
                         goto out;
         }
         /* Exhausted what can be done so it's blamo time */
-        if (out_of_memory(ac->zonelist, gfp_mask, order, ac->nodemask, false))
+        if (out_of_memory(ac->zonelist, gfp_mask, order, ac->nodemask, false)
+                        || WARN_ON_ONCE(gfp_mask & __GFP_NOFAIL))
                 *did_some_progress = 1;
 out:
         oom_zonelist_unlock(ac->zonelist, gfp_mask);
diff --git a/mm/vmalloc.c b/mm/vmalloc.c
index 35b25e1340ca..49abccf29a29 100644
--- a/mm/vmalloc.c
+++ b/mm/vmalloc.c
@@ -1418,6 +1418,7 @@ struct vm_struct *remove_vm_area(const void *addr)
                 spin_unlock(&vmap_area_lock);
 
                 vmap_debug_free_range(va->va_start, va->va_end);
+                kasan_free_shadow(vm);
                 free_unmap_vmap_area(va);
                 vm->size -= PAGE_SIZE;