From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from sender4-op-o12.zoho.com (sender4-op-o12.zoho.com [136.143.188.12]) (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 71767273810; Tue, 26 Aug 2025 17:42:18 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=pass smtp.client-ip=136.143.188.12 ARC-Seal:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1756230140; cv=pass; b=uN0YXtiK0Emo+L7JBtITHOfak6l9VgZBTFPz73LWhHz2P84YZpkb0C4HEUUpWbbG81ZcvC1OE0SEQjzJk7uwiUqYzGYdJ7HFeUKJy1sjo3l36cim+xc8GaCmEuWpwcphxvC7OMOJuvjchVOrWsKzFJ0rRLuibZ3Jcu1v9XNAPqU= ARC-Message-Signature:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1756230140; c=relaxed/simple; bh=SKa6oB+xZENU1ER26ztNgtC5zGJI5gY3JHY5TsSDDTs=; h=Content-Type:Mime-Version:Subject:From:In-Reply-To:Date:Cc: Message-Id:References:To; b=B2D0yh5jB2QRkwBfN1NCCqOlVqVgR3TLkEDZ3Q1dprhZ30xEVHbyTtv1VyKlK22Nhv6rLN8Tk232m6oLCMCkxshSH74V62rRzh411GmqZxsD4PWajj6bC+sUddKc4pyNUKTX48eOHRfbj4UvsUyQz21hvElEIvtZxudxyARX9Wg= ARC-Authentication-Results:i=2; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=collabora.com; spf=pass smtp.mailfrom=collabora.com; dkim=pass (1024-bit key) header.d=collabora.com header.i=daniel.almeida@collabora.com header.b=XyZ5kdkL; arc=pass smtp.client-ip=136.143.188.12 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=collabora.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=collabora.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=collabora.com header.i=daniel.almeida@collabora.com header.b="XyZ5kdkL" ARC-Seal: i=1; a=rsa-sha256; t=1756230120; cv=none; d=zohomail.com; s=zohoarc; b=MbCLR1N4T7xxHhjrV8fss6M5bmbFo3z4XgCfqouyEh9gVoantbMMcOqTQAhtbn49PY/jwCGLp4myHyzKdKBxdhaLZ9vkELDkihRkpEka+8AJqtZu8j3iWMPlbB/Mo0hcrxnuvzC9UiM/kQMTGqp8DNTyUWhxDeqRsi53Pf++1nw= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=zohomail.com; s=zohoarc; t=1756230120; h=Content-Type:Content-Transfer-Encoding:Cc:Cc:Date:Date:From:From:In-Reply-To:MIME-Version:Message-ID:References:Subject:Subject:To:To:Message-Id:Reply-To; bh=SK8f+GG2IKB3kWovus7R8gqvSJJ5ghEPh02buSFYcBs=; b=oGMOv7X6xkMCttZ8Id39EO9kdAHm7vTLO/lPodSRb+n8P9xRtpzkmhSOy/tOrQ/TBFcf4FGeKk1JUTMbjo1F/mBJKwSuA/0TTFREUlxTeuc4mTCUqnLkpbafN4nMVE+bFmIPjGPIq/rMZ946f7M+DQq1nIGuJqaZm5rmWGSmX9Q= ARC-Authentication-Results: i=1; mx.zohomail.com; dkim=pass header.i=collabora.com; spf=pass smtp.mailfrom=daniel.almeida@collabora.com; dmarc=pass header.from= DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; t=1756230120; s=zohomail; d=collabora.com; i=daniel.almeida@collabora.com; h=Content-Type:Mime-Version:Subject:Subject:From:From:In-Reply-To:Date:Date:Cc:Cc:Content-Transfer-Encoding:Message-Id:Message-Id:References:To:To:Reply-To; bh=SK8f+GG2IKB3kWovus7R8gqvSJJ5ghEPh02buSFYcBs=; b=XyZ5kdkLbxt9k5kI4kLuev94pk7VygW1xlLf1/9dREhh+fWcRpnY0hMCRWASiZvW 4DJePATnF/JTgkTCGMC2RIxzlUxoVvbpN1a0uAi7NMFOXtBVuotf6gYZxj+lZoQLkfi kB61A/b4Jn9J6PiR28Ig2VUM28J27PqYh7zm4l8g= Received: by mx.zohomail.com with SMTPS id 1756230118134842.9731315739924; Tue, 26 Aug 2025 10:41:58 -0700 (PDT) Content-Type: text/plain; charset=us-ascii Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 (Mac OS X Mail 16.0 \(3826.700.81\)) Subject: Re: [PATCH v3 3/5] rust: scatterlist: Add abstraction for sg_table From: Daniel Almeida In-Reply-To: Date: Tue, 26 Aug 2025 14:41:43 -0300 Cc: Alice Ryhl , akpm@linux-foundation.org, ojeda@kernel.org, alex.gaynor@gmail.com, boqun.feng@gmail.com, gary@garyguo.net, bjorn3_gh@protonmail.com, lossin@kernel.org, a.hindborg@kernel.org, tmgross@umich.edu, abdiel.janulgue@gmail.com, acourbot@nvidia.com, jgg@ziepe.ca, lyude@redhat.com, robin.murphy@arm.com, rust-for-linux@vger.kernel.org, linux-kernel@vger.kernel.org Content-Transfer-Encoding: quoted-printable Message-Id: <7DF83F8C-C036-4E0B-BADF-E915CCA0702C@collabora.com> References: <20250825132539.122412-1-dakr@kernel.org> <20250825132539.122412-4-dakr@kernel.org> To: Danilo Krummrich X-Mailer: Apple Mail (2.3826.700.81) X-ZohoMailClient: External > On 26 Aug 2025, at 11:32, Danilo Krummrich wrote: >=20 > On Tue Aug 26, 2025 at 4:16 PM CEST, Alice Ryhl wrote: >> On Mon, Aug 25, 2025 at 03:24:42PM +0200, Danilo Krummrich wrote: >> Overall LGTM. With comments addressed: >> Reviewed-by: Alice Ryhl >>=20 >>> +impl RawSGTable { >>> + fn new( >>> + pages: &mut [*mut bindings::page], >>=20 >> This should probably be unsafe due to the raw pointer. Or could we = pass >> any pointer here? >=20 > Good catch, we should indeed make this unsafe and add the = corresponding safety > requirements: >=20 > diff --git a/rust/kernel/scatterlist.rs b/rust/kernel/scatterlist.rs > index e76e5c2cbdc7..a562c0360842 100644 > --- a/rust/kernel/scatterlist.rs > +++ b/rust/kernel/scatterlist.rs > @@ -251,7 +251,12 @@ unsafe impl Send for RawSGTable {} > unsafe impl Sync for RawSGTable {} >=20 > impl RawSGTable { > - fn new( > + /// # Safety > + /// > + /// - `pages` must be a slice of valid `struct page *`. > + /// - The pages pointed to by `pages` must remain valid for the = entire lifetime of the returned > + /// [`RawSGTable`]. > + unsafe fn new( > pages: &mut [*mut bindings::page], > size: usize, > max_segment: u32, > @@ -355,7 +360,11 @@ fn new( > }; >=20 > Ok(try_pin_init!(&this in Self { > - sgt <- RawSGTable::new(&mut page_vec, size, max_segment, = flags), > + // SAFETY: > + // - `page_vec` is a `KVec` of valid `struct page *` = obtained from `pages`. > + // - The pages contained in `pages` remain valid for the = entire lifetime of the > + // `RawSGTable`. > + sgt <- unsafe { RawSGTable::new(&mut page_vec, size, = max_segment, flags) }, > dma <- { > // SAFETY: `this` is a valid pointer to uninitialized = memory. > let sgt =3D unsafe { &raw mut (*this.as_ptr()).sgt = }.cast(); >=20 >=20 Reviewed-by: Daniel Almeida