[PATCH v2 2/2] rust: mm: refactor zap_vma_range() to use contains_range()

From: liujinlong <[email protected]>

Open-code the overflow and range check in zap_vma_range() with the
contains_range() helper added in the previous patch.  Drop two local
variables and three lines of hand-rolled arithmetic in the process.

No functional change.

Signed-off-by: liujinlong <[email protected]>
---
 rust/kernel/mm/virt.rs | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/rust/kernel/mm/virt.rs b/rust/kernel/mm/virt.rs
index c11fb4c089bd..32749039f7c4 100644
--- a/rust/kernel/mm/virt.rs
+++ b/rust/kernel/mm/virt.rs
@@ -144,15 +144,14 @@ pub fn is_page_aligned_range(addr: usize, size: usize) -> bool {
     /// we must only assume that the leaf level is cleared.
     #[inline]
     pub fn zap_vma_range(&self, address: usize, size: usize) {
-        let (end, did_overflow) = address.overflowing_add(size);
-        if did_overflow || address < self.start() || self.end() < end {
+        if !self.contains_range(address, size) {
             // TODO: call WARN_ONCE once Rust version of it is added
             return;
         }
 
         // SAFETY: By the type invariants, the caller has read access to this VMA, which is
         // sufficient for this method call. This method has no requirements on the vma flags. The
-        // address range is checked to be within the vma.
+        // address range is checked to be within the vma via `contains_range`.
         unsafe { bindings::zap_vma_range(self.as_ptr(), address, size) };
     }
 
-- 
2.25.1