[PATCH] oom: less memdie

[linux-2.6] / mm / nommu.c

diff --git a/mm/nommu.c b/mm/nommu.c
index 23cfa8ec914a0b62c007cff2b177c44439260d1c..6a2a8aada40163c1653e8612ab29a4602e41d79c 100644 (file)
--- a/mm/nommu.c
+++ b/mm/nommu.c
@@ -221,7 +221,7 @@ long vwrite(char *buf, char *addr, unsigned long count)
  *     Allocate enough pages to cover @size from the page level
  *     allocator and map them into continguos kernel virtual space.
  *
- *     For tight cotrol over page level allocator and protection flags
+ *     For tight control over page level allocator and protection flags
  *     use __vmalloc() instead.
  */
 void *vmalloc(unsigned long size)
@@ -349,6 +349,15 @@ struct vm_area_struct *find_vma(struct mm_struct *mm, unsigned long addr)
 }
 EXPORT_SYMBOL(find_vma);
 
+/*
+ * find a VMA
+ * - we don't extend stack VMAs under NOMMU conditions
+ */
+struct vm_area_struct *find_extend_vma(struct mm_struct *mm, unsigned long addr)
+{
+       return find_vma(mm, addr);
+}
+
 /*
  * look up the first VMA exactly that exactly matches addr
  * - should be called with mm->mmap_sem at least held readlocked
@@ -488,15 +497,17 @@ static int validate_mmap_request(struct file *file,
            (flags & MAP_TYPE) != MAP_SHARED)
                return -EINVAL;
 
-       if (PAGE_ALIGN(len) == 0)
-               return addr;
-
-       if (len > TASK_SIZE)
+       if (!len)
                return -EINVAL;
 
+       /* Careful about overflows.. */
+       len = PAGE_ALIGN(len);
+       if (!len || len > TASK_SIZE)
+               return -ENOMEM;
+
        /* offset overflow? */
        if ((pgoff + (len >> PAGE_SHIFT)) < pgoff)
-               return -EINVAL;
+               return -EOVERFLOW;
 
        if (file) {
                /* validate file mapping requests */
@@ -939,7 +950,8 @@ unsigned long do_mmap_pgoff(struct file *file,
        up_write(&nommu_vma_sem);
        kfree(vml);
        if (vma) {
-               fput(vma->vm_file);
+               if (vma->vm_file)
+                       fput(vma->vm_file);
                kfree(vma);
        }
        return ret;
@@ -1153,11 +1165,6 @@ struct page *follow_page(struct vm_area_struct *vma, unsigned long address,
        return NULL;
 }
 
-struct vm_area_struct *find_extend_vma(struct mm_struct *mm, unsigned long addr)
-{
-       return NULL;
-}
-
 int remap_pfn_range(struct vm_area_struct *vma, unsigned long from,
                unsigned long to, unsigned long size, pgprot_t prot)
 {