From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-4316.protonmail.ch (mail-4316.protonmail.ch [185.70.43.16]) (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 581FF5695; Sat, 6 Jul 2024 10:41:40 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=185.70.43.16 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1720262502; cv=none; b=Misl5ALD0/fhH4P6kkaR7+mGwho1AanU1xXaj+nRC68tyUqvpWC4PdU+J6zCeyEkVoKMwT9w4aSX83b6CkXJo4pQ6mvRwWkaS8JF9VLVKWgp8YSQGJV7bH2ICj6IBzFZwCT2vYgnasbL3j28n0BRF02JZT/pXSRXFn2Tt8jvYO0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1720262502; c=relaxed/simple; bh=IJpjHkSPHZUsM3sBRTmM30fDfJnR3b8cLdQHNE7PHwI=; h=Date:To:From:Cc:Subject:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=q40quXAGfpoMJzNpVpbowNxdOaUXQ/Gw7RP3iR8cS66ATFOs0YEefQbRs0NZIu6JXMdRv5xHeeSlXPEABMSfIf6P/qYU0Imv3MQ1vbnJbvtH63Ql+OKJGjx9nWSoyqv4Oml30IDT6UozIkLR6cVPsnvqXaBSWhijODHtJvPSN+M= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=proton.me; spf=pass smtp.mailfrom=proton.me; dkim=pass (2048-bit key) header.d=proton.me header.i=@proton.me header.b=BISU96iq; arc=none smtp.client-ip=185.70.43.16 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=proton.me Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=proton.me Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=proton.me header.i=@proton.me header.b="BISU96iq" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=proton.me; s=protonmail; t=1720262493; x=1720521693; bh=w4h8NQSUQv78RzPLs46A/v8/4gFfYSJVkRa/3pfdLa4=; h=Date:To:From:Cc:Subject:Message-ID:In-Reply-To:References: Feedback-ID:From:To:Cc:Date:Subject:Reply-To:Feedback-ID: Message-ID:BIMI-Selector; b=BISU96iqzVfwxZZ4KKpV0mrKB57o7HBIW+unDSKiZBGezBRvY3+Pnn1vAFBtY8WUk TnX2tScvHUlaaCQC03Z3O5UrMOzZaPzSxPAKqJtOUswBMcv4kzfwe+Z0QqYROwuQGr Jyj1LMpU4UnO4a0F/ATvoNoSdHZ8SD743USpZJt+l+pNo5GNQAvfbCMFbmfACXMH7g SyyonGq42CcO9EQdXnED++rocaA2DxtDZdq/7FyOE2fxcHPajGmEsOos4YjJNaWmzW QGocEuekT5jpu/sIbKGWhSbsE0j5fVGeRCFDFjxYuE4HFVoE1EwK3aZqbU1wHqnMP5 OKGvBedP9oDMQ== Date: Sat, 06 Jul 2024 10:41:28 +0000 To: Danilo Krummrich , ojeda@kernel.org, alex.gaynor@gmail.com, wedsonaf@gmail.com, boqun.feng@gmail.com, gary@garyguo.net, bjorn3_gh@protonmail.com, a.hindborg@samsung.com, aliceryhl@google.com From: Benno Lossin 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 Subject: Re: [PATCH 07/20] rust: alloc: implement `Vmalloc` allocator Message-ID: <596c6446-eca4-46a8-91c5-e71e92c61062@proton.me> In-Reply-To: <20240704170738.3621-8-dakr@redhat.com> References: <20240704170738.3621-1-dakr@redhat.com> <20240704170738.3621-8-dakr@redhat.com> Feedback-ID: 71780778:user:proton X-Pm-Message-ID: b26e30de595f87380eaa36b76b9b95b4582c341f Precedence: bulk X-Mailing-List: rust-for-linux@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable On 04.07.24 19:06, Danilo Krummrich wrote: > @@ -112,6 +118,55 @@ unsafe fn alloc_zeroed(&self, layout: Layout) -> *mu= t u8 { > } > } >=20 > +unsafe impl Allocator for Vmalloc { > + unsafe fn realloc( > + &self, > + src: *mut u8, > + old_size: usize, > + layout: Layout, > + flags: Flags, > + ) -> Result, AllocError> { > + let mut size =3D aligned_size(layout); > + > + let dst =3D if size =3D=3D 0 { > + // SAFETY: `src` is guaranteed to be previously allocated wi= th this `Allocator` or NULL. > + unsafe { bindings::vfree(src.cast()) }; > + NonNull::dangling() > + } else if size <=3D old_size { > + size =3D old_size; > + NonNull::new(src).ok_or(AllocError)? > + } else { > + // SAFETY: `src` is guaranteed to point to valid memory with= a size of at least > + // `old_size`, which was previously allocated with this `All= ocator` or NULL. > + let dst =3D unsafe { bindings::__vmalloc_noprof(size as u64,= flags.0) }; > + > + // Validate that we actually allocated the requested memory. > + let dst =3D NonNull::new(dst.cast()).ok_or(AllocError)?; > + > + if !src.is_null() { > + // SAFETY: `src` is guaranteed to point to valid memory = with a size of at least > + // `old_size`; `dst` is guaranteed to point to valid mem= ory with a size of at least > + // `size`. > + unsafe { > + core::ptr::copy_nonoverlapping( > + src, > + dst.as_ptr(), > + core::cmp::min(old_size, size), > + ) > + }; > + > + // SAFETY: `src` is guaranteed to be previously allocate= d with this `Allocator` or > + // NULL. > + unsafe { bindings::vfree(src.cast()) } > + } > + > + dst > + }; If we had not a single realloc, but shrink/grow/free/alloc, then we would not need these checks here, I personally would prefer that, what do you guys think?=20 --- Cheers, Benno > + > + Ok(NonNull::slice_from_raw_parts(dst, size)) > + } > +} > + > #[global_allocator] > static ALLOCATOR: Kmalloc =3D Kmalloc; >=20 > diff --git a/rust/kernel/alloc/allocator_test.rs b/rust/kernel/alloc/allo= cator_test.rs > index 3a0abe65491d..b2d7db492ba6 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( > -- > 2.45.2 >=20