Merge tag 'v3.10.72' into linux-linaro-lsk

[firefly-linux-kernel-4.4.55.git] / mm / memory.c

diff --git a/mm/memory.c b/mm/memory.c
index ebe0f285c0e7094b431c726f752aa354f61eff80..280930f51ef61877bbabc033b176bc1441b70766 100644 (file)
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -118,6 +118,8 @@ __setup("norandmaps", disable_randmaps);
 unsigned long zero_pfn __read_mostly;
 unsigned long highest_memmap_pfn __read_mostly;
 
+EXPORT_SYMBOL(zero_pfn);
+
 /*
  * CONFIG_MMU architectures set up ZERO_PAGE in their paging_init()
  */
@@ -834,20 +836,20 @@ copy_one_pte(struct mm_struct *dst_mm, struct mm_struct *src_mm,
                if (!pte_file(pte)) {
                        swp_entry_t entry = pte_to_swp_entry(pte);
 
-                       if (swap_duplicate(entry) < 0)
-                               return entry.val;
-
-                       /* make sure dst_mm is on swapoff's mmlist. */
-                       if (unlikely(list_empty(&dst_mm->mmlist))) {
-                               spin_lock(&mmlist_lock);
-                               if (list_empty(&dst_mm->mmlist))
-                                       list_add(&dst_mm->mmlist,
-                                                &src_mm->mmlist);
-                               spin_unlock(&mmlist_lock);
-                       }
-                       if (likely(!non_swap_entry(entry)))
+                       if (likely(!non_swap_entry(entry))) {
+                               if (swap_duplicate(entry) < 0)
+                                       return entry.val;
+
+                               /* make sure dst_mm is on swapoff's mmlist. */
+                               if (unlikely(list_empty(&dst_mm->mmlist))) {
+                                       spin_lock(&mmlist_lock);
+                                       if (list_empty(&dst_mm->mmlist))
+                                               list_add(&dst_mm->mmlist,
+                                                        &src_mm->mmlist);
+                                       spin_unlock(&mmlist_lock);
+                               }
                                rss[MM_SWAPENTS]++;
-                       else if (is_migration_entry(entry)) {
+                       } else if (is_migration_entry(entry)) {
                                page = migration_entry_to_page(entry);
 
                                if (PageAnon(page))
@@ -3200,7 +3202,7 @@ static inline int check_stack_guard_page(struct vm_area_struct *vma, unsigned lo
                if (prev && prev->vm_end == address)
                        return prev->vm_flags & VM_GROWSDOWN ? 0 : -ENOMEM;
 
-               expand_downwards(vma, address - PAGE_SIZE);
+               return expand_downwards(vma, address - PAGE_SIZE);
        }
        if ((vma->vm_flags & VM_GROWSUP) && address + PAGE_SIZE == vma->vm_end) {
                struct vm_area_struct *next = vma->vm_next;
@@ -3209,7 +3211,7 @@ static inline int check_stack_guard_page(struct vm_area_struct *vma, unsigned lo
                if (next && next->vm_start == address + PAGE_SIZE)
                        return next->vm_flags & VM_GROWSUP ? 0 : -ENOMEM;
 
-               expand_upwards(vma, address + PAGE_SIZE);
+               return expand_upwards(vma, address + PAGE_SIZE);
        }
        return 0;
 }
@@ -3754,22 +3756,14 @@ unlock:
 /*
  * By the time we get here, we already hold the mm semaphore
  */
-int handle_mm_fault(struct mm_struct *mm, struct vm_area_struct *vma,
-               unsigned long address, unsigned int flags)
+static int __handle_mm_fault(struct mm_struct *mm, struct vm_area_struct *vma,
+                            unsigned long address, unsigned int flags)
 {
        pgd_t *pgd;
        pud_t *pud;
        pmd_t *pmd;
        pte_t *pte;
 
-       __set_current_state(TASK_RUNNING);
-
-       count_vm_event(PGFAULT);
-       mem_cgroup_count_vm_event(mm, PGFAULT);
-
-       /* do counter updates before entering really critical section. */
-       check_sync_rss_stat(current);
-
        if (unlikely(is_vm_hugetlb_page(vma)))
                return hugetlb_fault(mm, vma, address, flags);
 
@@ -3850,6 +3844,43 @@ retry:
        return handle_pte_fault(mm, vma, address, pte, pmd, flags);
 }
 
+int handle_mm_fault(struct mm_struct *mm, struct vm_area_struct *vma,
+                   unsigned long address, unsigned int flags)
+{
+       int ret;
+
+       __set_current_state(TASK_RUNNING);
+
+       count_vm_event(PGFAULT);
+       mem_cgroup_count_vm_event(mm, PGFAULT);
+
+       /* do counter updates before entering really critical section. */
+       check_sync_rss_stat(current);
+
+       /*
+        * Enable the memcg OOM handling for faults triggered in user
+        * space.  Kernel faults are handled more gracefully.
+        */
+       if (flags & FAULT_FLAG_USER)
+               mem_cgroup_oom_enable();
+
+       ret = __handle_mm_fault(mm, vma, address, flags);
+
+       if (flags & FAULT_FLAG_USER) {
+               mem_cgroup_oom_disable();
+                /*
+                 * The task may have entered a memcg OOM situation but
+                 * if the allocation error was handled gracefully (no
+                 * VM_FAULT_OOM), there is no need to kill anything.
+                 * Just clean up the OOM state peacefully.
+                 */
+                if (task_in_memcg_oom(current) && !(ret & VM_FAULT_OOM))
+                        mem_cgroup_oom_synchronize(false);
+       }
+
+       return ret;
+}
+
 #ifndef __PAGETABLE_PUD_FOLDED
 /*
  * Allocate page upper directory.
@@ -4059,7 +4090,7 @@ int generic_access_phys(struct vm_area_struct *vma, unsigned long addr,
        if (follow_phys(vma, addr, write, &prot, &phys_addr))
                return -EINVAL;
 
-       maddr = ioremap_prot(phys_addr, PAGE_SIZE, prot);
+       maddr = ioremap_prot(phys_addr, PAGE_ALIGN(len + offset), prot);
        if (write)
                memcpy_toio(maddr + offset, buf, len);
        else