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 F19C71A08B1; Sun, 9 Mar 2025 09:48:53 +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=1741513734; cv=none; b=T4e0D1aaXN2RXKRdJ4mvqadUWLOiv+eZWpFJA+/Ij1d6TQ0qt9QXPqxsDr8+bfTD1KffxO3r1SGMgeVI44GB9f84Hls81EupYZ2AwgLQ5rHjaqnBluZimn1AJpEr5fQbtDizyKrU9mVJB2SsdLBDqYYAOMIJg+2fN/6HCYsskYs= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1741513734; c=relaxed/simple; bh=8TUcSEjAPQZ7GawzI+cbALX9UZsqpg/pTEQkAwDzcbg=; h=Subject:To:Cc:From:Date:In-Reply-To:Message-ID:MIME-Version: Content-Type; b=QLuo7HV7S7EIVFchjsVxL1HsBzGLLl9SXlymqUSX4owt5lkNUs6Qd/uv4YGAfye0xPXX7iRD5uJLydV89QD4anRebS3IP/873K8n+p/zgQMG32nTx461iGv+7bVzHbYDFKecKUih2QrhsebDBqkFhx5yJoJr/yE7jdCwVan3tVI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=E4niPuAt; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="E4niPuAt" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 0A138C4CEE5; Sun, 9 Mar 2025 09:48:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1741513733; bh=8TUcSEjAPQZ7GawzI+cbALX9UZsqpg/pTEQkAwDzcbg=; h=Subject:To:Cc:From:Date:In-Reply-To:From; b=E4niPuAtNS1rwb3rQekS+bHR/okdh/vYzmc5B9XDc7ONSNTaEwAoTsRKNIAkhWkQ2 L+rOHG9DT4ajm7DsJsjqalkaRqoFyD8tU1xwtEmlmmqaxsEJvWEgem0g/lxHe8hQT0 sj/Y93y6Wa17yTzyB7zH0nutSfROqR7zVkzIfSIQ= Subject: Patch "rust: alloc: implement `Allocator` for `Kmalloc`" has been added to the 6.12-stable tree To: aliceryhl@google.com,benno.lossin@proton.me,dakr@kernel.org,gary@garyguo.net,gregkh@linuxfoundation.org,hi@alyssa.is,noisycoil@disroot.org,ojeda@kernel.org,patches@lists.linux.dev,sashal@kernel.org Cc: From: Date: Sun, 09 Mar 2025 10:46:49 +0100 In-Reply-To: <20250307225008.779961-26-ojeda@kernel.org> Message-ID: <2025030949-landfall-blabber-c90b@gregkh> Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit X-stable: commit X-Patchwork-Hint: ignore This is a note to let you know that I've just added the patch titled rust: alloc: implement `Allocator` for `Kmalloc` to the 6.12-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: rust-alloc-implement-allocator-for-kmalloc.patch and it can be found in the queue-6.12 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let know about it. >From stable+bounces-121480-greg=kroah.com@vger.kernel.org Fri Mar 7 23:51:53 2025 From: Miguel Ojeda Date: Fri, 7 Mar 2025 23:49:32 +0100 Subject: rust: alloc: implement `Allocator` for `Kmalloc` To: Greg Kroah-Hartman , Sasha Levin , stable@vger.kernel.org Cc: Danilo Krummrich , Alice Ryhl , Alyssa Ross , NoisyCoil , patches@lists.linux.dev, Miguel Ojeda Message-ID: <20250307225008.779961-26-ojeda@kernel.org> From: Danilo Krummrich commit a34822d1c4c93085f635b922441a017bd7e959b0 upstream. Implement `Allocator` for `Kmalloc`, the kernel's default allocator, typically used for objects smaller than page size. All memory allocations made with `Kmalloc` end up in `krealloc()`. It serves as allocator for the subsequently introduced types `KBox` and `KVec`. Reviewed-by: Benno Lossin Reviewed-by: Gary Guo Signed-off-by: Danilo Krummrich Link: https://lore.kernel.org/r/20241004154149.93856-7-dakr@kernel.org Signed-off-by: Miguel Ojeda Signed-off-by: Greg Kroah-Hartman --- rust/kernel/alloc/allocator.rs | 31 ++++++++++++++++++++++++++++--- 1 file changed, 28 insertions(+), 3 deletions(-) --- a/rust/kernel/alloc/allocator.rs +++ b/rust/kernel/alloc/allocator.rs @@ -13,10 +13,16 @@ use core::alloc::{GlobalAlloc, Layout}; use core::ptr; use core::ptr::NonNull; -use crate::alloc::AllocError; +use crate::alloc::{AllocError, Allocator}; use crate::bindings; -struct Kmalloc; +/// The contiguous kernel allocator. +/// +/// `Kmalloc` is typically used for physically contiguous allocations up to page size, but also +/// supports larger allocations up to `bindings::KMALLOC_MAX_SIZE`, which is hardware specific. +/// +/// For more details see [self]. +pub struct Kmalloc; /// Returns a proper size to alloc a new object aligned to `new_layout`'s alignment. fn aligned_size(new_layout: Layout) -> usize { @@ -53,8 +59,10 @@ struct ReallocFunc( unsafe extern "C" fn(*const core::ffi::c_void, usize, u32) -> *mut core::ffi::c_void, ); -#[expect(dead_code)] impl ReallocFunc { + // INVARIANT: `krealloc` satisfies the type invariants. + const KREALLOC: Self = Self(bindings::krealloc); + /// # Safety /// /// This method has the same safety requirements as [`Allocator::realloc`]. @@ -106,6 +114,23 @@ impl ReallocFunc { } } +// SAFETY: `realloc` delegates to `ReallocFunc::call`, which guarantees that +// - 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 Kmalloc { + #[inline] + unsafe fn realloc( + ptr: Option>, + layout: Layout, + old_layout: Layout, + flags: Flags, + ) -> Result, AllocError> { + // SAFETY: `ReallocFunc::call` has the same safety requirements as `Allocator::realloc`. + unsafe { ReallocFunc::KREALLOC.call(ptr, layout, old_layout, flags) } + } +} + // SAFETY: TODO. unsafe impl GlobalAlloc for Kmalloc { unsafe fn alloc(&self, layout: Layout) -> *mut u8 { Patches currently in stable-queue which might be from ojeda@kernel.org are queue-6.12/drm-panic-avoid-reimplementing-iterator-find.patch queue-6.12/documentation-rust-add-coding-guidelines-on-lints.patch queue-6.12/rust-provide-proper-code-documentation-titles.patch queue-6.12/rust-alloc-make-allocator-module-public.patch queue-6.12/rust-alloc-remove-vecext-extension.patch queue-6.12/rust-alloc-implement-reallocfunc.patch queue-6.12/rust-alloc-separate-aligned_size-from-krealloc_aligned.patch queue-6.12/rust-enable-clippy-unnecessary_safety_comment-lint.patch queue-6.12/rust-alloc-update-module-comment-of-alloc.rs.patch queue-6.12/rust-kbuild-expand-rusttest-target-for-macros.patch queue-6.12/rust-error-use-core-alloc-layouterror.patch queue-6.12/rust-str-test-replace-alloc-format.patch queue-6.12/loongarch-use-asm_reachable.patch queue-6.12/rust-alloc-implement-allocator-for-kmalloc.patch queue-6.12/rust-alloc-implement-collect-for-intoiter.patch queue-6.12/rust-alloc-introduce-arraylayout.patch queue-6.12/rust-alloc-implement-vmalloc-allocator.patch queue-6.12/documentation-rust-discuss-in-the-guidelines.patch queue-6.12/rust-error-check-for-config-test-in-error-name.patch queue-6.12/rust-enable-clippy-ignored_unit_patterns-lint.patch queue-6.12/rust-enable-clippy-unnecessary_safety_doc-lint.patch queue-6.12/rust-alloc-add-box-to-prelude.patch queue-6.12/kbuild-rust-remove-the-alloc-crate-and-globalalloc.patch queue-6.12/rust-alloc-add-allocator-trait.patch queue-6.12/rust-treewide-switch-to-our-kernel-box-type.patch queue-6.12/rust-introduce-.clippy.toml.patch queue-6.12/rust-alloc-rename-kernelallocator-to-kmalloc.patch queue-6.12/rust-alloc-implement-cmalloc-in-module-allocator_test.patch queue-6.12/drm-panic-allow-verbose-version-check.patch queue-6.12/rust-map-__kernel_size_t-and-friends-also-to-usize-isize.patch queue-6.12/rust-alloc-add-module-allocator_test.patch queue-6.12/rust-replace-clippy-dbg_macro-with-disallowed_macros.patch queue-6.12/rust-alloc-add-__gfp_nowarn-to-flags.patch queue-6.12/rust-enable-clippy-s-check-private-items.patch queue-6.12/rust-error-make-conversion-functions-public.patch queue-6.12/rust-sort-global-rust-flags.patch queue-6.12/rust-alloc-implement-contains-for-flags.patch queue-6.12/rust-init-remove-unneeded.patch queue-6.12/rust-use-custom-ffi-integer-types.patch queue-6.12/rust-sync-remove-unneeded.patch queue-6.12/rust-treewide-switch-to-the-kernel-vec-type.patch queue-6.12/rust-alloc-implement-kvmalloc-allocator.patch queue-6.12/drm-panic-correctly-indent-continuation-of-line-in-list-item.patch queue-6.12/rust-alloc-implement-kernel-vec-type.patch queue-6.12/rust-workqueue-remove-unneeded.patch queue-6.12/rust-error-optimize-error-type-to-use-nonzero.patch queue-6.12/drm-panic-remove-unnecessary-borrow-in-alignment_pattern.patch queue-6.12/rust-alloc-remove-extension-of-std-s-box.patch queue-6.12/rust-block-fix-formatting-in-gendisk-doc.patch queue-6.12/rust-enable-rustdoc-unescaped_backticks-lint.patch queue-6.12/rust-fix-size_t-in-bindgen-prototypes-of-c-builtins.patch queue-6.12/rust-enable-clippy-undocumented_unsafe_blocks-lint.patch queue-6.12/rust-alloc-add-vec-to-prelude.patch queue-6.12/rust-alloc-implement-intoiterator-for-vec.patch queue-6.12/rust-alloc-implement-kernel-box.patch queue-6.12/drm-panic-remove-redundant-field-when-assigning-value.patch queue-6.12/rust-types-avoid-repetition-in-as-from-bytes-impls.patch queue-6.12/rust-start-using-the-attribute.patch queue-6.12/drm-panic-allow-verbose-boolean-for-clarity.patch queue-6.12/maintainers-add-entry-for-the-rust-alloc-module.patch queue-6.12/rust-alloc-fix-arraylayout-allocations.patch queue-6.12/drm-panic-prefer-eliding-lifetimes.patch