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 B735F231A2A; Mon, 10 Mar 2025 17:19:36 +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=1741627176; cv=none; b=cPjTS42rrY5jzI+qqpz3sPcbiv1SwEoL0ez/ZeEx8O8cGaFGVQM4QxOvKkKJITU/BCMCJWFJZ92MBEwMRoifPagD48FbeyYTejnSLXjIE4cJubB46bj5lIQDjpUcKp3xJOTLQT/NEIuexbHy+sHyLDnZa5d0+2xQVhC45NLeik8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1741627176; c=relaxed/simple; bh=y0Rtoe9EXW7V/i2M9H4xwACfZk8WXLiCzxRlKnaRF9k=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=XSPTMXaRB5Zj//BmwaQPBJuPaNPF5R9ubWUcxQqLzEVlW8y1Y2cC667qvNIrxToCFgZgLQy5WjuC7SbUN5X5X7QGPXtrr8WkdWSmtTeD4Oou80bwUfVtpzFX9cisUemBBoYfxFnp+GOQe5d0OO6Ww8CWSQaHEt/LjiqRdyskOIU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=c+V+RepI; 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="c+V+RepI" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 3CC77C4CEE5; Mon, 10 Mar 2025 17:19:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1741627176; bh=y0Rtoe9EXW7V/i2M9H4xwACfZk8WXLiCzxRlKnaRF9k=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=c+V+RepIB7suo17sBWt8i4w8p0M+9Eww45HwLQGts4I/2sJsV3Aqncc65l0PQj6VU A9bZ5zUEGMIgVVl6Q/Ge+nujiu6cefkbhFwnNasuoYt1d423GSzgClicdTnkIFTPii 9OROmaJnOun/Z7ZdyVNx7YSlAm8edVucOoUwKEcw= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Alice Ryhl , Benno Lossin , Gary Guo , Danilo Krummrich , Miguel Ojeda Subject: [PATCH 6.12 038/269] rust: alloc: implement `Vmalloc` allocator Date: Mon, 10 Mar 2025 18:03:11 +0100 Message-ID: <20250310170459.238561991@linuxfoundation.org> X-Mailer: git-send-email 2.48.1 In-Reply-To: <20250310170457.700086763@linuxfoundation.org> References: <20250310170457.700086763@linuxfoundation.org> User-Agent: quilt/0.68 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.12-stable review patch. If anyone has any objections, please let me know. ------------------ From: Danilo Krummrich commit 61c004781d6b928443052e7a6cf84b35d4f61401 upstream. 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 Reviewed-by: Gary Guo Signed-off-by: Danilo Krummrich Link: https://lore.kernel.org/r/20241004154149.93856-9-dakr@kernel.org Signed-off-by: Miguel Ojeda Signed-off-by: Greg Kroah-Hartman --- 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 --- 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" --- /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); +} --- a/rust/kernel/alloc/allocator.rs +++ b/rust/kernel/alloc/allocator.rs @@ -15,6 +15,7 @@ use core::ptr::NonNull; use crate::alloc::{AllocError, Allocator}; use crate::bindings; +use crate::pr_warn; /// The contiguous kernel allocator. /// @@ -24,6 +25,15 @@ use crate::bindings; /// For more details see [self]. pub struct Kmalloc; +/// 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 = Self(bindings::krealloc); + // INVARIANT: `vrealloc` satisfies the type invariants. + const VREALLOC: Self = Self(bindings::vrealloc); + /// # Safety /// /// This method has the same safety requirements as [`Allocator::realloc`]. @@ -168,6 +181,30 @@ unsafe impl GlobalAlloc for Kmalloc { } } +// 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 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 memory, which was previously + // allocated with this `Allocator`. + unsafe { ReallocFunc::VREALLOC.call(ptr, layout, old_layout, flags) } + } +} + #[global_allocator] static ALLOCATOR: Kmalloc = Kmalloc; --- a/rust/kernel/alloc/allocator_test.rs +++ b/rust/kernel/alloc/allocator_test.rs @@ -7,6 +7,7 @@ use core::alloc::Layout; use core::ptr::NonNull; pub struct Kmalloc; +pub type Vmalloc = Kmalloc; unsafe impl Allocator for Kmalloc { unsafe fn realloc(