rust: allocator: Use krealloc_aligned() in KernelAllocator::alloc

This fixes the potential issue that when KernelAllocator is used, the allocation may be mis-aligned due to SLAB's alignment guarantee. Signed-off-by: Boqun Feng <[email protected]> Reviewed-by: Andreas Hindborg <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Miguel Ojeda <[email protected]>
Rust-for-Linux · Jul 31, 2023 · 3e44cc6 · 3e44cc6
1 parent 10a6032
commit 3e44cc6
Showing 1 changed file with 3 additions and 3 deletions.
diff --git a/rust/kernel/allocator.rs b/rust/kernel/allocator.rs
@@ -41,9 +41,9 @@ unsafe fn krealloc_aligned(ptr: *mut u8, new_layout: Layout, flags: bindings::gf
 
 unsafe impl GlobalAlloc for KernelAllocator {
     unsafe fn alloc(&self, layout: Layout) -> *mut u8 {
-        // `krealloc()` is used instead of `kmalloc()` because the latter is
-        // an inline function and cannot be bound to as a result.
-        unsafe { bindings::krealloc(ptr::null(), layout.size(), bindings::GFP_KERNEL) as *mut u8 }
+        // SAFETY: `ptr::null_mut()` is null and `layout` has a non-zero size by the function safety
+        // requirement.
+        unsafe { krealloc_aligned(ptr::null_mut(), layout, bindings::GFP_KERNEL) }
     }
 
     unsafe fn dealloc(&self, ptr: *mut u8, _layout: Layout) {