[PATCH v2 2/4] mm/vmalloc: remove the redundant boundary check

From: Baoquan He
Date: Tue Jun 07 2022 - 07:05:09 EST


In function 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.

Signed-off-by: Baoquan He <bhe@xxxxxxxxxx>
Reviewed-by: Uladzislau Rezki (Sony) <urezki@xxxxxxxxx>
---
mm/vmalloc.c | 6 ++----
1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/mm/vmalloc.c b/mm/vmalloc.c
index f9d45aa90b7c..b711bf82fd5d 100644
--- 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",
--
2.34.1