[PATCH] RLIMIT_AS checking fix

[linux-2.6-block.git] / mm / mmap.c

diff --git a/mm/mmap.c b/mm/mmap.c
index 6ea204cc751e4d2f0fe4a7d213bab9ae90ad58c4..1ec0f6e9c0d86a4f9d523f9f497a0a0ea720a255 100644 (file)
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -1009,8 +1009,7 @@ munmap_back:
        }
 
        /* Check against address space limit. */
-       if ((mm->total_vm << PAGE_SHIFT) + len
-           > current->signal->rlim[RLIMIT_AS].rlim_cur)
+       if (!may_expand_vm(mm, len >> PAGE_SHIFT))
                return -ENOMEM;
 
        if (accountable && (!(flags & MAP_NORESERVE) ||
@@ -1421,7 +1420,7 @@ static int acct_stack_growth(struct vm_area_struct * vma, unsigned long size, un
        struct rlimit *rlim = current->signal->rlim;
 
        /* address space limit tests */
-       if (mm->total_vm + grow > rlim[RLIMIT_AS].rlim_cur >> PAGE_SHIFT)
+       if (!may_expand_vm(mm, grow))
                return -ENOMEM;
 
        /* Stack limit test */
@@ -1848,8 +1847,7 @@ unsigned long do_brk(unsigned long addr, unsigned long len)
        }
 
        /* Check against address space limits *after* clearing old maps... */
-       if ((mm->total_vm << PAGE_SHIFT) + len
-           > current->signal->rlim[RLIMIT_AS].rlim_cur)
+       if (!may_expand_vm(mm, len >> PAGE_SHIFT))
                return -ENOMEM;
 
        if (mm->map_count > sysctl_max_map_count)
@@ -2019,3 +2017,19 @@ struct vm_area_struct *copy_vma(struct vm_area_struct **vmap,
        }
        return new_vma;
 }
+
+/*
+ * Return true if the calling process may expand its vm space by the passed
+ * number of pages
+ */
+int may_expand_vm(struct mm_struct *mm, unsigned long npages)
+{
+       unsigned long cur = mm->total_vm;       /* pages */
+       unsigned long lim;
+
+       lim = current->signal->rlim[RLIMIT_AS].rlim_cur >> PAGE_SHIFT;
+
+       if (cur + npages > lim)
+               return 0;
+       return 1;
+}