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 B8EE915C15A; Mon, 5 Aug 2024 15:20:46 +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=1722871246; cv=none; b=BFe9J6lHY+bhnuEQxO3ZgHdELLT5Xu3aNVYeJdUQfwc/XEboFJuBDO2TRjNfZEFPC3NMuZ+esdNzIhtI69CL7Wbn2mgOa6znBORGDWeXL24QIV3LpQgHg0XVJKEYhPi2ZT3wqN04qnI+4izSSTrdc+NVUGl3Ulho4+Kiin2q82Q= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1722871246; c=relaxed/simple; bh=pL/2tk9r+RNw9Wnwj5An+62HaTNk3XqGiHLSI686pwI=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=Kt8RWpgad/oemVRgMO1TpZVo3C5tjMEMIB5rcuIBJUnoummGd5SS1ybT0viBctw3V1vh4rjeTqMIrS2z7Z5mKvLWiup/MXKjpyx5eu7uWFLq4IUM0kj4RLU3sdZ4Nyat+mHxelq8qxDdezp1W48Gif6d0rR5EtV0TsA2r/VnNGI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=oXd667Z+; 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="oXd667Z+" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 8143FC4AF10; Mon, 5 Aug 2024 15:20:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1722871246; bh=pL/2tk9r+RNw9Wnwj5An+62HaTNk3XqGiHLSI686pwI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=oXd667Z+v76rsJOSJiwugYw609RU4d6zvS4IpyxU3I92MkwzAqckdCues4v2T1H3A vkNdhCTwWgRMUDvgFaBOa4CrrpzOesoJFqdWJ6s5Ur+j1mSjOVvnC6CHSRNSy02wF8 1vz1ux3aD2y8DiGsV6Qy6v9tyQP7p4fpsN4M8C4TPWzqAxiQ5Ghaigs4Ib6+QGFBDY HwBY/mF2ukc7pbEUUFvR6HJnpCx4dqW2N7+r/MBeru8bfevLcarBnon3YJlxnqLRVo OFkXc6ZGL7uSiXg29DTUz8afCaANoREEuu2D9NqxQ8XEIYAb8hSoHDax9s9v8CgShz wB6sBGnyImjxg== 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 06/28] rust: alloc: implement `Vmalloc` allocator Date: Mon, 5 Aug 2024 17:19:25 +0200 Message-ID: <20240805152004.5039-7-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 `Vmalloc`, the kernel's virtually contiguous allocator, typically used for larger objects, (much) larger than page size. All memory allocations made with `Vmalloc` end up in `vrealloc()`. Reviewed-by: Alice Ryhl Signed-off-by: Danilo Krummrich --- rust/helpers.c | 7 +++++++ rust/kernel/alloc/allocator.rs | 32 +++++++++++++++++++++++++++++ rust/kernel/alloc/allocator_test.rs | 1 + 3 files changed, 40 insertions(+) diff --git a/rust/helpers.c b/rust/helpers.c index 9f7275493365..7406943f887d 100644 --- a/rust/helpers.c +++ b/rust/helpers.c @@ -33,6 +33,7 @@ #include #include #include +#include #include #include @@ -199,6 +200,12 @@ void *rust_helper_krealloc(const void *objp, size_t new_size, gfp_t flags) } EXPORT_SYMBOL_GPL(rust_helper_krealloc); +void *rust_helper_vrealloc(const void *p, size_t size, gfp_t flags) +{ + return vrealloc(p, size, flags); +} +EXPORT_SYMBOL_GPL(rust_helper_vrealloc); + /* * `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 c6ad1dd59dd0..bb55895cbd03 100644 --- a/rust/kernel/alloc/allocator.rs +++ b/rust/kernel/alloc/allocator.rs @@ -9,6 +9,7 @@ use crate::alloc::{AllocError, Allocator}; use crate::bindings; +use crate::pr_warn; /// The contiguous kernel allocator. /// @@ -16,6 +17,12 @@ /// `bindings::krealloc`. pub struct Kmalloc; +/// The virtually contiguous kernel allocator. +/// +/// The vmalloc allocator allocates pages from the page level allocator and maps them into the +/// contiguous kernel virtual space. +pub struct Vmalloc; + /// 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. @@ -61,6 +68,11 @@ fn krealloc() -> Self { Self(bindings::krealloc) } + // INVARIANT: `vrealloc` satisfies the type invariants. + fn vrealloc() -> Self { + Self(bindings::vrealloc) + } + /// # Safety /// /// This method has the exact same safety requirements as `Allocator::realloc`. @@ -141,6 +153,26 @@ unsafe fn alloc_zeroed(&self, layout: Layout) -> *mut u8 { } } +unsafe impl Allocator for Vmalloc { + unsafe fn realloc( + ptr: Option>, + layout: Layout, + flags: Flags, + ) -> Result, AllocError> { + let realloc = ReallocFunc::vrealloc(); + + // TODO: Support alignments larger than PAGE_SIZE. + if layout.align() > bindings::PAGE_SIZE { + pr_warn!("Vmalloc 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 4785efc474a7..e7bf2982f68f 100644 --- a/rust/kernel/alloc/allocator_test.rs +++ b/rust/kernel/alloc/allocator_test.rs @@ -7,6 +7,7 @@ use core::ptr::NonNull; pub struct Kmalloc; +pub type Vmalloc = Kmalloc; unsafe impl Allocator for Kmalloc { unsafe fn realloc( -- 2.45.2