mm/vmalloc: remove the redundant boundary check

In find_va_links(), when traversing the vmap_area tree, the comparing to
check if the passed in 'va' is above or below 'tmp_va' is redundant,
assuming both 'va' and 'tmp_va' has ->va_start <= ->va_end.

Here, to simplify the checking as code change.

Link: https://lkml.kernel.org/r/20220607105958.382076-3-bhe@redhat.com
Signed-off-by: Baoquan He <bhe@redhat.com>
Reviewed-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
Cc: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/mm/vmalloc.c b/mm/vmalloc.c
index f9d45aa..b711bf8 100644 (file)
--- a/mm/vmalloc.c
+++ b/mm/vmalloc.c
@@ -874,11 +874,9 @@ find_va_links(struct vmap_area *va,
                 * Trigger the BUG() if there are sides(left/right)
                 * or full overlaps.
                 */
-               if (va->va_start < tmp_va->va_end &&
-                               va->va_end <= tmp_va->va_start)
+               if (va->va_end <= tmp_va->va_start)
                        link = &(*link)->rb_left;
-               else if (va->va_end > tmp_va->va_start &&
-                               va->va_start >= tmp_va->va_end)
+               else if (va->va_start >= tmp_va->va_end)
                        link = &(*link)->rb_right;
                else {
                        WARN(1, "vmalloc bug: 0x%lx-0x%lx overlaps with 0x%lx-0x%lx\n",