From nobody Thu Nov 28 15:50:34 2024 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 133ED1CB307; Tue, 1 Oct 2024 15:00:59 +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=1727794860; cv=none; b=C+1CCslMpfw1G5oUboJ8gTsRA4FKn5WQJy0CYZbreRBeOBHdg4LRJN61FguyFqZaOVb+NNbR/kQjOxgc/xArLmVdVu9rxBvupQVrZydkPRDSHyCfr+rxXw7rgTeMB2KH+OwmwIxk/dNPDa7tp6LEO223c+d7naAtnSh4ioJ2Tq4= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1727794860; c=relaxed/simple; bh=HLcg425F90NHvfln7+CkNFLbyp+1IauQlWGwrTXVWkQ=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=Vtbo1aHckyMGtPO036s19BGdPGSFL7f4cbsqrEzofPcj9HKZTlG8enq0LTHgul/gmvzjJVakOXlDTcft7GIKEjuo6WBX4q+WQ4IFtQ9AjwDhhT4BTH6lGqAzjo+76qQigWNwL8KiGD8UKZLhlTFfkvKiAj/9J/f6vmzYRsuUrAA= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=FEC2PB2q; 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="FEC2PB2q" Received: by smtp.kernel.org (Postfix) with ESMTPSA id B9F07C4CEC6; Tue, 1 Oct 2024 15:00:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1727794859; bh=HLcg425F90NHvfln7+CkNFLbyp+1IauQlWGwrTXVWkQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=FEC2PB2qqWlaxBrCYs0tyLDHvYQfQynYdKreOHCr6nywYxT6IzPfGdvyLLVujp+1c IDSftsjEYeaOIcOKZp5tq+lv+9qQkWTeM9RUsOZeFduP3EpcAUZfRSbC0APhvmic8K 9NlxqiCYYaxMtFvZhXV8SBZCR4GCD07CTRhc52RKjG3gkNmQ4w+7uS4jrzwBd37x3k pf5ch8ng/WAb8VeDeZmI+Vres6Sbx77xHRWw1bvS2A1qHj9EJeWEGkCR+YviUl2Jn8 00cTL1V7LwXT2aG58SmKOypU6fCUb+q+aHxLoIj3SbF97PG3K4613T1gEFvGesC+er PQvO1BPB05kow== 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 v8 08/29] rust: alloc: implement `Vmalloc` allocator Date: Tue, 1 Oct 2024 16:59:43 +0200 Message-ID: <20241001150008.183102-9-dakr@kernel.org> X-Mailer: git-send-email 2.46.1 In-Reply-To: <20241001150008.183102-1-dakr@kernel.org> References: <20241001150008.183102-1-dakr@kernel.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" 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 Reviewed-by: Benno Lossin Signed-off-by: Danilo Krummrich Reviewed-by: Gary Guo --- rust/helpers/helpers.c | 1 + rust/helpers/vmalloc.c | 9 +++++++ rust/kernel/alloc/allocator.rs | 37 +++++++++++++++++++++++++++++ rust/kernel/alloc/allocator_test.rs | 1 + 4 files changed, 48 insertions(+) create mode 100644 rust/helpers/vmalloc.c diff --git a/rust/helpers/helpers.c b/rust/helpers/helpers.c index 30f40149f3a9..20a0c69d5cc7 100644 --- a/rust/helpers/helpers.c +++ b/rust/helpers/helpers.c @@ -22,5 +22,6 @@ #include "spinlock.c" #include "task.c" #include "uaccess.c" +#include "vmalloc.c" #include "wait.c" #include "workqueue.c" diff --git a/rust/helpers/vmalloc.c b/rust/helpers/vmalloc.c new file mode 100644 index 000000000000..80d34501bbc0 --- /dev/null +++ b/rust/helpers/vmalloc.c @@ -0,0 +1,9 @@ +// SPDX-License-Identifier: GPL-2.0 + +#include + +void * __must_check __realloc_size(2) +rust_helper_vrealloc(const void *p, size_t size, gfp_t flags) +{ + return vrealloc(p, size, flags); +} diff --git a/rust/kernel/alloc/allocator.rs b/rust/kernel/alloc/allocator.rs index 4f3c3ab7c7a2..f341e9ed5b7c 100644 --- a/rust/kernel/alloc/allocator.rs +++ b/rust/kernel/alloc/allocator.rs @@ -15,6 +15,7 @@ =20 use crate::alloc::{AllocError, Allocator}; use crate::bindings; +use crate::pr_warn; =20 /// The contiguous kernel allocator. /// @@ -24,6 +25,15 @@ /// For more details see [self]. pub struct Kmalloc; =20 +/// The virtually contiguous kernel allocator. +/// +/// `Vmalloc` allocates pages from the page level allocator and maps them = into the contiguous kernel +/// virtual space. It is typically used for large allocations. The memory = allocated with this +/// allocator is not physically contiguous. +/// +/// For more details see [self]. +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. @@ -63,6 +73,9 @@ impl ReallocFunc { // INVARIANT: `krealloc` satisfies the type invariants. const KREALLOC: Self =3D Self(bindings::krealloc); =20 + // INVARIANT: `vrealloc` satisfies the type invariants. + const VREALLOC: Self =3D Self(bindings::vrealloc); + /// # Safety /// /// This method has the same safety requirements as [`Allocator::reall= oc`]. @@ -166,6 +179,30 @@ unsafe fn alloc_zeroed(&self, layout: Layout) -> *mut = u8 { } } =20 +// SAFETY: `realloc` delegates to `ReallocFunc::call`, which guarantees th= at +// - memory remains valid until it is explicitly freed, +// - passing a pointer to a valid memory allocation is OK, +// - `realloc` satisfies the guarantees, since `ReallocFunc::call` has the= same. +unsafe impl Allocator for Vmalloc { + #[inline] + unsafe fn realloc( + ptr: Option>, + layout: Layout, + old_layout: Layout, + flags: Flags, + ) -> Result, AllocError> { + // 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 me= mory, which was previously + // allocated with this `Allocator`. + unsafe { ReallocFunc::VREALLOC.call(ptr, layout, old_layout, flags= ) } + } +} + #[global_allocator] static ALLOCATOR: Kmalloc =3D Kmalloc; =20 diff --git a/rust/kernel/alloc/allocator_test.rs b/rust/kernel/alloc/alloca= tor_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; =20 pub struct Kmalloc; +pub type Vmalloc =3D Kmalloc; =20 unsafe impl Allocator for Kmalloc { unsafe fn realloc( --=20 2.46.1