1 files changed, 28 insertions, 20 deletions

diff --git a/mm/mmap.c b/mm/mmap.c
index 3b3ed0bb9fdb..1abb9185a686 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -919,7 +919,6 @@ unsigned long do_mmap_pgoff(struct file *file, unsigned long addr,
         struct inode *inode;
         unsigned int vm_flags;
         int error;
-        int accountable = 1;
         unsigned long reqprot = prot;
 
         /*
@@ -1020,8 +1019,6 @@ unsigned long do_mmap_pgoff(struct file *file, unsigned long addr,
                                         return -EPERM;
                                 vm_flags &= ~VM_MAYEXEC;
                         }
-                        if (is_file_hugepages(file))
-                                accountable = 0;
 
                         if (!file->f_op || !file->f_op->mmap)
                                 return -ENODEV;
@@ -1057,8 +1054,7 @@ unsigned long do_mmap_pgoff(struct file *file, unsigned long addr,
         if (error)
                 return error;
 
-        return mmap_region(file, addr, len, flags, vm_flags, pgoff,
-                           accountable);
+        return mmap_region(file, addr, len, flags, vm_flags, pgoff);
 }
 EXPORT_SYMBOL(do_mmap_pgoff);
 
@@ -1096,17 +1092,23 @@ int vma_wants_writenotify(struct vm_area_struct *vma)
 
 /*
  * We account for memory if it's a private writeable mapping,
- * and VM_NORESERVE wasn't set.
+ * not hugepages and VM_NORESERVE wasn't set.
  */
-static inline int accountable_mapping(unsigned int vm_flags)
+static inline int accountable_mapping(struct file *file, unsigned int vm_flags)
 {
+        /*
+         * hugetlb has its own accounting separate from the core VM
+         * VM_HUGETLB may not be set yet so we cannot check for that flag.
+         */
+        if (file && is_file_hugepages(file))
+                return 0;
+
         return (vm_flags & (VM_NORESERVE | VM_SHARED | VM_WRITE)) == VM_WRITE;
 }
 
 unsigned long mmap_region(struct file *file, unsigned long addr,
                           unsigned long len, unsigned long flags,
-                          unsigned int vm_flags, unsigned long pgoff,
-                          int accountable)
+                          unsigned int vm_flags, unsigned long pgoff)
 {
         struct mm_struct *mm = current->mm;
         struct vm_area_struct *vma, *prev;
@@ -1132,18 +1134,22 @@ munmap_back:
 
         /*
          * Set 'VM_NORESERVE' if we should not account for the
-         * memory use of this mapping. We only honor MAP_NORESERVE
-         * if we're allowed to overcommit memory.
+         * memory use of this mapping.
          */
-        if ((flags & MAP_NORESERVE) && sysctl_overcommit_memory != OVERCOMMIT_NEVER)
-                vm_flags |= VM_NORESERVE;
-        if (!accountable)
-                vm_flags |= VM_NORESERVE;
+        if ((flags & MAP_NORESERVE)) {
+                /* We honor MAP_NORESERVE if allowed to overcommit */
+                if (sysctl_overcommit_memory != OVERCOMMIT_NEVER)
+                        vm_flags |= VM_NORESERVE;
+
+                /* hugetlb applies strict overcommit unless MAP_NORESERVE */
+                if (file && is_file_hugepages(file))
+                        vm_flags |= VM_NORESERVE;
+        }
 
         /*
          * Private writable mapping: check memory availability
          */
-        if (accountable_mapping(vm_flags)) {
+        if (accountable_mapping(file, vm_flags)) {
                 charged = len >> PAGE_SHIFT;
                 if (security_vm_enough_memory(charged))
                         return -ENOMEM;
@@ -2082,12 +2088,8 @@ void exit_mmap(struct mm_struct *mm)
         unsigned long end;
 
         /* mm's last user has gone, and its about to be pulled down */
-        arch_exit_mmap(mm);
         mmu_notifier_release(mm);
 
-        if (!mm->mmap)  /* Can happen if dup_mmap() received an OOM */
-                return;
-
         if (mm->locked_vm) {
                 vma = mm->mmap;
                 while (vma) {
@@ -2096,7 +2098,13 @@ void exit_mmap(struct mm_struct *mm)
                         vma = vma->vm_next;
                 }
         }
+
+        arch_exit_mmap(mm);
+
         vma = mm->mmap;
+        if (!vma)       /* Can happen if dup_mmap() received an OOM */
+                return;
+
         lru_add_drain();
         flush_cache_mm(mm);
         tlb = tlb_gather_mmu(mm, 1);