From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 5546F1891D6; Mon, 12 Aug 2024 18:24:19 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1723487059; cv=none; b=DR6/P0ylGzpFUc89acYhMOAKYJzNFmvA5n+iMlVtJl7FyxLIMCYZOCnaHon4NuWMnj4NFnvRtKrR26tVoJ6KkJOey7EJ7XoOBadFeNXuws7Qrit3P1/o2ryovJZqE/YoOXRqgL1USG0rBzCBbGAeuat4OPkDb04qklijzC1RJlc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1723487059; c=relaxed/simple; bh=p++mQr6O15JhVUHtMmsU1D7fc1KQnWeRmH3GDyn4naw=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=aB0hdadmCD4CYF4PNNHP2T7D9VVHhqwPfn2AsO9vvbx2P0SfKjN9H0oFhsH3d7C9F5rICMAHN1CijVyesishgs+CZMFBUsTzyvyyyhzJc96QGbytZLiIWcDD2TYV5pNFQ9G/9FNB2DwmW4yfUH+R33jWVuZUy+9zcYgxTedNnmc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=c0I8hd5A; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="c0I8hd5A" Received: by smtp.kernel.org (Postfix) with ESMTPSA id F08F9C4AF0D; Mon, 12 Aug 2024 18:24:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1723487058; bh=p++mQr6O15JhVUHtMmsU1D7fc1KQnWeRmH3GDyn4naw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=c0I8hd5AqEtUJ1AqcltnJQJXgDifadIagb8OT4ht7RND3/LIpX13gvQjzt3gLQowI ftjf2eUBi+kRnz1lX7eL9vGAeiEQ8VSt/93xhlmq3bo51SkTTtLhVlA1JeSJlhL1vO kKy1fu1ZpAWRTSx0A6dHnPwjSFST7YO372xKlpVClxYIjCcUPHvkSj+fQ1ApyURzYL iEsA/zOqK25c8hP18hXK60sIIPLcYcpYrmTHnk0vQhpz7wJPKOG5cBX2AXOvB7Pt59 OuPvw6w4Pra2zExwy8Z5Xaqski4YFdaIJkkvFVea5Z2LMfKRfUtJYYqefeQFClV0Vt gsbOh1+Jy/6+Q== From: Danilo Krummrich To: ojeda@kernel.org, alex.gaynor@gmail.com, wedsonaf@gmail.com, boqun.feng@gmail.com, gary@garyguo.net, bjorn3_gh@protonmail.com, benno.lossin@proton.me, a.hindborg@samsung.com, aliceryhl@google.com, akpm@linux-foundation.org Cc: daniel.almeida@collabora.com, faith.ekstrand@collabora.com, boris.brezillon@collabora.com, lina@asahilina.net, mcanal@igalia.com, zhiw@nvidia.com, cjia@nvidia.com, jhubbard@nvidia.com, airlied@redhat.com, ajanulgu@redhat.com, lyude@redhat.com, linux-kernel@vger.kernel.org, rust-for-linux@vger.kernel.org, linux-mm@kvack.org, Danilo Krummrich Subject: [PATCH v5 02/26] rust: alloc: separate `aligned_size` from `krealloc_aligned` Date: Mon, 12 Aug 2024 20:22:48 +0200 Message-ID: <20240812182355.11641-3-dakr@kernel.org> X-Mailer: git-send-email 2.45.2 In-Reply-To: <20240812182355.11641-1-dakr@kernel.org> References: <20240812182355.11641-1-dakr@kernel.org> Precedence: bulk X-Mailing-List: rust-for-linux@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Separate `aligned_size` from `krealloc_aligned`. Subsequent patches implement `Allocator` derivates, such as `Kmalloc`, that require `aligned_size` and replace the original `krealloc_aligned`. Reviewed-by: Alice Ryhl Reviewed-by: Benno Lossin Signed-off-by: Danilo Krummrich --- rust/kernel/alloc/allocator.rs | 19 ++++++++++++------- 1 file changed, 12 insertions(+), 7 deletions(-) diff --git a/rust/kernel/alloc/allocator.rs b/rust/kernel/alloc/allocator.rs index e6ea601f38c6..c83b6dff896d 100644 --- a/rust/kernel/alloc/allocator.rs +++ b/rust/kernel/alloc/allocator.rs @@ -8,6 +8,17 @@ struct KernelAllocator; +/// Returns a proper size to alloc a new object aligned to `new_layout`'s alignment. +fn aligned_size(new_layout: Layout) -> usize { + // Customized layouts from `Layout::from_size_align()` can have size < align, so pad first. + let layout = new_layout.pad_to_align(); + + // Note that `layout.size()` (after padding) is guaranteed to be a multiple of `layout.align()` + // which together with the slab guarantees means the `krealloc` will return a properly aligned + // object (see comments in `kmalloc()` for more information). + layout.size() +} + /// Calls `krealloc` with a proper size to alloc a new object aligned to `new_layout`'s alignment. /// /// # Safety @@ -15,13 +26,7 @@ /// - `ptr` can be either null or a pointer which has been allocated by this allocator. /// - `new_layout` must have a non-zero size. pub(crate) unsafe fn krealloc_aligned(ptr: *mut u8, new_layout: Layout, flags: Flags) -> *mut u8 { - // Customized layouts from `Layout::from_size_align()` can have size < align, so pad first. - let layout = new_layout.pad_to_align(); - - // Note that `layout.size()` (after padding) is guaranteed to be a multiple of `layout.align()` - // which together with the slab guarantees means the `krealloc` will return a properly aligned - // object (see comments in `kmalloc()` for more information). - let size = layout.size(); + let size = aligned_size(new_layout); // SAFETY: // - `ptr` is either null or a pointer returned from a previous `k{re}alloc()` by the -- 2.45.2