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 993CF15E5BD; Mon, 5 Aug 2024 15:20:52 +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=1722871252; cv=none; b=UaAiwqNnHZ0jMTjy4WCImnr/7L57xLRP9st4z4XbWMkwOOJUbXbEg6W7AZEmLTpcmSuTj9f4QkrpJWReZVjGhxPkfVhouIXVkmqIiDofLmzo8Q+T/V5DhUdexnPAYEq8bJMFw41V+7WnwyI8M7A3YxXrAJ6TKHLbv6uIYVqdZwk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1722871252; c=relaxed/simple; bh=4X9wSdLX4mWoeYIrAd5wlz1K/X7N03r6vTnYVQGkAO4=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=HexsrV6JQSldxAXoy64AUaQw8iWFYtyyt5fHD+BIhsBe92WEtosxATNjKLxv1/xAdCPncfyizuOXX19gGruL20dygvFNY3onAv/eW+w3Z8cZStehf0BCawcWCxyCh1V+QowZTv/WBgHYmlL9uFCsJ/wwRs/HrPb86qiQTKX0QAk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=GJAyHZFL; 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="GJAyHZFL" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 13970C4AF0B; Mon, 5 Aug 2024 15:20:46 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1722871252; bh=4X9wSdLX4mWoeYIrAd5wlz1K/X7N03r6vTnYVQGkAO4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=GJAyHZFLBa7Fe6Up0rMI4tOEodUpG6ICWZsYB2kS9icTwHsv0wtG66ktGFCoOjyxY pXCRPWZeor7R6vBE9LRo5MJNRiM4BLH8xXJI0PIBnIyvPd/YHQmtjyKZ9m/jKa8bTL VZd48fllVOFNugpuOyQOJWmnk7hjLZQPVN0ha/0JFtJrb6oF/A0kXmCcBG17FIZtWn 1xTk0MDC4qqfztXrPzUFAVOzBguUtCZHmg1pKUEEQCZqyIslqywKAbJ2MBEq+2ZAFG ZKjqokDjnAsjTlUD/6tbLaa5ffRzlKIlpoxxiV/EsMBdEOW2q5N3RO8OhT02M4Fvay jHkfPN2IYfWaQ== 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, acurrid@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 v4 07/28] rust: alloc: implement `KVmalloc` allocator Date: Mon, 5 Aug 2024 17:19:26 +0200 Message-ID: <20240805152004.5039-8-dakr@kernel.org> X-Mailer: git-send-email 2.45.2 In-Reply-To: <20240805152004.5039-1-dakr@kernel.org> References: <20240805152004.5039-1-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 Implement `Allocator` for `KVmalloc`, an `Allocator` that tries to allocate memory wth `kmalloc` first and, on failure, falls back to `vmalloc`. All memory allocations made with `KVmalloc` end up in `kvrealloc_noprof()`; all frees in `kvfree()`. Reviewed-by: Alice Ryhl Signed-off-by: Danilo Krummrich --- rust/helpers.c | 6 ++++++ rust/kernel/alloc/allocator.rs | 31 +++++++++++++++++++++++++++++ rust/kernel/alloc/allocator_test.rs | 1 + 3 files changed, 38 insertions(+) diff --git a/rust/helpers.c b/rust/helpers.c index 7406943f887d..3285a85765ff 100644 --- a/rust/helpers.c +++ b/rust/helpers.c @@ -206,6 +206,12 @@ void *rust_helper_vrealloc(const void *p, size_t size, gfp_t flags) } EXPORT_SYMBOL_GPL(rust_helper_vrealloc); +void *rust_helper_kvrealloc(const void *p, size_t size, gfp_t flags) +{ + return kvrealloc(p, size, flags); +} +EXPORT_SYMBOL_GPL(rust_helper_kvrealloc); + /* * `bindgen` binds the C `size_t` type as the Rust `usize` type, so we can * use it in contexts where Rust expects a `usize` like slice (array) indices. diff --git a/rust/kernel/alloc/allocator.rs b/rust/kernel/alloc/allocator.rs index bb55895cbd03..91ff21372a8f 100644 --- a/rust/kernel/alloc/allocator.rs +++ b/rust/kernel/alloc/allocator.rs @@ -23,6 +23,12 @@ /// contiguous kernel virtual space. pub struct Vmalloc; +/// The kvmalloc kernel allocator. +/// +/// Attempt to allocate physically contiguous memory, but upon failure, fall back to non-contiguous +/// (vmalloc) allocation. +pub struct KVmalloc; + /// 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. @@ -73,6 +79,11 @@ fn vrealloc() -> Self { Self(bindings::vrealloc) } + // INVARIANT: `vrealloc` satisfies the type invariants. + fn kvrealloc() -> Self { + Self(bindings::kvrealloc) + } + /// # Safety /// /// This method has the exact same safety requirements as `Allocator::realloc`. @@ -173,6 +184,26 @@ unsafe fn realloc( } } +unsafe impl Allocator for KVmalloc { + unsafe fn realloc( + ptr: Option>, + layout: Layout, + flags: Flags, + ) -> Result, AllocError> { + let realloc = ReallocFunc::kvrealloc(); + + // TODO: Support alignments larger than PAGE_SIZE. + if layout.align() > bindings::PAGE_SIZE { + pr_warn!("KVmalloc does not support alignments larger than PAGE_SIZE yet.\n"); + return Err(AllocError); + } + + // SAFETY: If not `None`, `ptr` is guaranteed to point to valid memory, which was previously + // allocated with this `Allocator`. + unsafe { realloc.call(ptr, layout, flags) } + } +} + #[global_allocator] static ALLOCATOR: Kmalloc = Kmalloc; diff --git a/rust/kernel/alloc/allocator_test.rs b/rust/kernel/alloc/allocator_test.rs index e7bf2982f68f..1b2642c547ec 100644 --- a/rust/kernel/alloc/allocator_test.rs +++ b/rust/kernel/alloc/allocator_test.rs @@ -8,6 +8,7 @@ pub struct Kmalloc; pub type Vmalloc = Kmalloc; +pub type KVmalloc = Kmalloc; unsafe impl Allocator for Kmalloc { unsafe fn realloc( -- 2.45.2