A non-NULL vma returned from find_vma() implies:
vma->vm_start <= start
Since len != 0, the following condition always hods:
vma->vm_start < start + len = end
This means the if check would never be true.
This patch removes this redundant check and fix two typo in comment.
Signed-off-by: Wei Yang <richard.weiyang@xxxxxxxxx>
---
mm/mmap.c | 10 +++-------
1 file changed, 3 insertions(+), 7 deletions(-)
diff --git a/mm/mmap.c b/mm/mmap.c
index 8d6449e74431..94660ddfa2c1 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -414,7 +414,7 @@ static void vma_gap_update(struct vm_area_struct *vma)
{
/*
* As it turns out, RB_DECLARE_CALLBACKS() already created a callback
- * function that does exacltly what we want.
+ * function that does exactly what we want.
*/
vma_gap_callbacks_propagate(&vma->vm_rb, NULL);
}
@@ -1621,7 +1621,7 @@ SYSCALL_DEFINE1(old_mmap, struct mmap_arg_struct __user *, arg)
#endif /* __ARCH_WANT_SYS_OLD_MMAP */
/*
- * Some shared mappigns will want the pages marked read-only
+ * Some shared mappings will want the pages marked read-only
* to track write events. If so, we'll downgrade vm_page_prot
* to the private version (using protection_map[] without the
* VM_SHARED bit).
@@ -2705,12 +2705,8 @@ int do_munmap(struct mm_struct *mm, unsigned long start, size_t len,
if (!vma)
return 0;
prev = vma->vm_prev;
- /* we have start < vma->vm_end */
-
- /* if it doesn't overlap, we have nothing.. */
+ /* we have vma->vm_start <= start < vma->vm_end */
end = start + len;
- if (vma->vm_start >= end)
- return 0;
/*
* If we need to split any vma, do it now to save pain later.
--
2.15.1
