Commit 753df96b authored by Baoquan He's avatar Baoquan He Committed by Andrew Morton
Browse files

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: default avatarBaoquan He <bhe@redhat.com>
Reviewed-by: default avatarUladzislau Rezki (Sony) <urezki@gmail.com>
Cc: Christoph Hellwig <hch@infradead.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent 1b23ff80

mm/vmalloc.c

+2 −4
Original line number Diff line number Diff line
@@ -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",