Boqun Feng boqun.feng@gmail.com writes:
From: Björn Roy Baron bjorn3_gh@protonmail.com
While there are default impls for these methods, using the respective C api's is faster. Currently neither the existing nor these new GlobalAlloc method implementations are actually called. Instead the __rust_* function defined below the GlobalAlloc impl are used. With rustc 1.71 these functions will be gone and all allocation calls will go through the GlobalAlloc implementation.
Link: https://github.com/Rust-for-Linux/linux/issues/68 Signed-off-by: Björn Roy Baron bjorn3_gh@protonmail.com [boqun: add size adjustment for alignment requirement] Signed-off-by: Boqun Feng boqun.feng@gmail.com
Reviewed-by: Andreas Hindborg a.hindborg@samsung.com
rust/kernel/allocator.rs | 27 +++++++++++++++++++++++++++ 1 file changed, 27 insertions(+)
diff --git a/rust/kernel/allocator.rs b/rust/kernel/allocator.rs index 1aec688cf0e0..6f1f50465ab3 100644 --- a/rust/kernel/allocator.rs +++ b/rust/kernel/allocator.rs @@ -51,6 +51,33 @@ unsafe fn dealloc(&self, ptr: *mut u8, _layout: Layout) { bindings::kfree(ptr as *const core::ffi::c_void); } }
- unsafe fn realloc(&self, ptr: *mut u8, layout: Layout, new_size: usize) -> *mut u8 {
// SAFETY:// - `new_size`, when rounded up to the nearest multiple of `layout.align()`, will not// overflow `isize` by the function safety requirement.// - `layout.align()` is a proper alignment (i.e. not zero and must be a power of two).let layout = unsafe { Layout::from_size_align_unchecked(new_size, layout.align()) };// SAFETY:// - `ptr` is either null or a pointer allocated by this allocator by the function safety// requirement.// - the size of `layout` is not zero because `new_size` is not zero by the function safety// requirement.unsafe { krealloc_aligned(ptr, layout, bindings::GFP_KERNEL) }- }
- unsafe fn alloc_zeroed(&self, layout: Layout) -> *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 | bindings::__GFP_ZERO,)}- }
} #[global_allocator]