diff --git a/rust/helpers.c b/rust/helpers.c index 49a5e1a4f0ae9..fed48f590f383 100644 --- a/rust/helpers.c +++ b/rust/helpers.c @@ -16,6 +16,8 @@ * * All symbols are exported as GPL-only to guarantee no GPL-only feature is * accidentally exposed. + * + * Sorted alphabetically. */ #include @@ -23,10 +25,10 @@ #include #include #include -#include #include -#include +#include #include +#include #include __noreturn void rust_helper_BUG(void) diff --git a/rust/kernel/allocator.rs b/rust/kernel/allocator.rs index 9363b527be664..72d66c23883c1 100644 --- 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) { @@ -51,6 +51,33 @@ unsafe impl GlobalAlloc for KernelAllocator { 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] diff --git a/rust/kernel/sync/lock.rs b/rust/kernel/sync/lock.rs index a2216325632df..70a785f047546 100644 --- a/rust/kernel/sync/lock.rs +++ b/rust/kernel/sync/lock.rs @@ -72,8 +72,8 @@ pub unsafe trait Backend { /// A mutual exclusion primitive. /// -/// Exposes one of the kernel locking primitives. Which one is exposed depends on the lock backend -/// specified as the generic parameter `B`. +/// Exposes one of the kernel locking primitives. Which one is exposed depends on the lock +/// [`Backend`] specified as the generic parameter `B`. #[pin_data] pub struct Lock { /// The kernel lock object. @@ -126,7 +126,7 @@ impl Lock { /// A lock guard. /// -/// Allows mutual exclusion primitives that implement the `Backend` trait to automatically unlock +/// Allows mutual exclusion primitives that implement the [`Backend`] trait to automatically unlock /// when a guard goes out of scope. It also provides a safe and convenient way to access the data /// protected by the lock. #[must_use = "the lock unlocks immediately when the guard is unused"]