From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5F839E77180 for ; Mon, 16 Dec 2024 14:51:23 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id D5B116B0099; Mon, 16 Dec 2024 09:51:22 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id CE3956B009A; Mon, 16 Dec 2024 09:51:22 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id B5E546B009B; Mon, 16 Dec 2024 09:51:22 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0017.hostedemail.com [216.40.44.17]) by kanga.kvack.org (Postfix) with ESMTP id 935BC6B0099 for ; Mon, 16 Dec 2024 09:51:22 -0500 (EST) Received: from smtpin25.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay03.hostedemail.com (Postfix) with ESMTP id 154E0A103A for ; Mon, 16 Dec 2024 14:51:22 +0000 (UTC) X-FDA: 82901109228.25.313EE07 Received: from nyc.source.kernel.org (nyc.source.kernel.org [147.75.193.91]) by imf27.hostedemail.com (Postfix) with ESMTP id C334E40005 for ; Mon, 16 Dec 2024 14:50:47 +0000 (UTC) Authentication-Results: imf27.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=BKecVwFY; spf=pass (imf27.hostedemail.com: domain of a.hindborg@kernel.org designates 147.75.193.91 as permitted sender) smtp.mailfrom=a.hindborg@kernel.org; dmarc=pass (policy=quarantine) header.from=kernel.org ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1734360653; a=rsa-sha256; cv=none; b=UloiDLGPOHskcywSe+cYz65oMVLERyJlMPqlx47zcxvxabYKlcNZemoZotqpzX9h0wWCKt NPY/Hd1zFon4suJwh3XlPnGQQA+UMYAevF7Ow+/y6DHMGJtyIe+xbKgbXUE93VaPiCFEDr 3T9w5vpPwpPHQOB2vPyLeR3IDy9AAVU= ARC-Authentication-Results: i=1; imf27.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=BKecVwFY; spf=pass (imf27.hostedemail.com: domain of a.hindborg@kernel.org designates 147.75.193.91 as permitted sender) smtp.mailfrom=a.hindborg@kernel.org; dmarc=pass (policy=quarantine) header.from=kernel.org ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1734360653; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=c5Rjty8JnDtXiq1ClBihpW1g8Jkba3aMSJQottm0NfM=; b=5tFWFQSQlYozmT8UBMipsk0zRAkVmQwJRVqFzjKzNfC1C1dcj7bCbxfi5xGkzR17On2JDf cfX/rSxZ7J6SXQGMquB344osxI9N05fmQa0RZ9H9JkS+B/zVG5Ldi+jskZqry0PGr+VHU4 VTsFijaGly2dXwdg8YG+UJL8PjGaUsM= Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by nyc.source.kernel.org (Postfix) with ESMTP id F2301A41758; Mon, 16 Dec 2024 14:49:28 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id A849AC4CEDF; Mon, 16 Dec 2024 14:51:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1734360679; bh=G6rSvWZlkRq/BV2Xt1BzQjLVBDeiRc/FFqaxFjTsrDk=; h=From:To:Cc:Subject:In-Reply-To:References:Date:From; b=BKecVwFY14JZXcx4RVIDEvqaQrLitthRez+NbSnCmHHEnr656TlNfqnWpI2AssvV9 H7d+v+F3slh6EAaNdkArKKN6IWAy9stlUuHLAVCXx4IWhJxpbP6lbsaTD9NzFSgsca VlCmb8fOq4rT49bQWIlbZfhBo/UQbnPK+9GD4U+Wov3LNd5SqbJc1VaLRlClOKkWW0 tH79lqXSSZOnWLQbZoQFFuwEE/imx6WqHwi+KUOQFdkFyNm2RuEWMWBrf6UELM0T7c PCWVh+ltYefoI+axtGP03WS1w9+w4ibMabBAydzRgAzwzIng1RwgKok3UrUFTow+aI WuKz+JXEIHJ/A== From: Andreas Hindborg To: "Alice Ryhl" Cc: "Miguel Ojeda" , "Matthew Wilcox" , "Lorenzo Stoakes" , "Vlastimil Babka" , "John Hubbard" , "Liam R. Howlett" , "Andrew Morton" , "Greg Kroah-Hartman" , "Arnd Bergmann" , "Christian Brauner" , "Jann Horn" , "Suren Baghdasaryan" , "Alex Gaynor" , "Boqun Feng" , "Gary Guo" , =?utf-8?Q?Bj=C3=B6rn?= Roy Baron , "Benno Lossin" , "Trevor Gross" , , , Subject: Re: [PATCH v11 7/8] rust: miscdevice: add mmap support In-Reply-To: <20241211-vma-v11-7-466640428fc3@google.com> (Alice Ryhl's message of "Wed, 11 Dec 2024 10:37:11 +0000") References: <20241211-vma-v11-0-466640428fc3@google.com> <20241211-vma-v11-7-466640428fc3@google.com> Date: Mon, 16 Dec 2024 14:53:59 +0100 Message-ID: <87jzbzag3s.fsf@kernel.org> MIME-Version: 1.0 Content-Type: text/plain X-Rspamd-Queue-Id: C334E40005 X-Stat-Signature: tmxzk6nz8s3fgc3z89qi8h14hqs5c4o4 X-Rspam-User: X-Rspamd-Server: rspam09 X-HE-Tag: 1734360647-252844 X-HE-Meta: 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 TCmLK32k B/AvwnQ4JWH32F8o1f0YLSul/MfGfcKnaj1UoIq86NLvw0KBWF/aT1HsK5Fk0YdOtBI7XZeZfZHbRfWqG/XmeAevkFerfPdqG6T6xjbeC2K7ZYvyHFOa11KhYFio7HvlsIsEOxPUuwVz+AMwy2fmWq43KWv6Y7PT9EsHcRYuoWZhrGTWWI8dfyc1egMKPFAoTkpGxqNn3odpa0yOz+12gtbt7XDQJTqv7TT6CGOj0CUr9LOpfgVJsZFHvNv9tGRpYss9y8BkYx9eu5j3nHpIOkS0p8UhjY97LZ1a3H60Hu1lTDHJcZM6WfSP+NIQOeJAli2Wz X-Bogosity: Ham, tests=bogofilter, spamicity=0.116061, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: "Alice Ryhl" writes: > Add the ability to write a file_operations->mmap hook in Rust when using > the miscdevice abstraction. The `vma` argument to the `mmap` hook uses > the `VmAreaNew` type from the previous commit; this type provides the > correct set of operations for a file_operations->mmap hook. > > Acked-by: Lorenzo Stoakes (for mm bits) > Signed-off-by: Alice Ryhl > --- > rust/kernel/miscdevice.rs | 37 +++++++++++++++++++++++++++++++++++++ > 1 file changed, 37 insertions(+) > > diff --git a/rust/kernel/miscdevice.rs b/rust/kernel/miscdevice.rs > index 7e2a79b3ae26..e5366f9c6d7f 100644 > --- a/rust/kernel/miscdevice.rs > +++ b/rust/kernel/miscdevice.rs > @@ -11,6 +11,8 @@ > use crate::{ > bindings, > error::{to_result, Error, Result, VTABLE_DEFAULT_ERROR}, > + fs::File, > + mm::virt::VmAreaNew, > prelude::*, > str::CStr, > types::{ForeignOwnable, Opaque}, > @@ -110,6 +112,15 @@ fn release(device: Self::Ptr) { > drop(device); > } > > + /// Handle for mmap. > + fn mmap( > + _device: ::Borrowed<'_>, > + _file: &File, > + _vma: &VmAreaNew, > + ) -> Result { > + kernel::build_error!(VTABLE_DEFAULT_ERROR) > + } > + > /// Handler for ioctls. > /// > /// The `cmd` argument is usually manipulated using the utilties in [`kernel::ioctl`]. > @@ -156,6 +167,7 @@ impl VtableHelper { > const VTABLE: bindings::file_operations = bindings::file_operations { > open: Some(fops_open::), > release: Some(fops_release::), > + mmap: maybe_fn(T::HAS_MMAP, fops_mmap::), > unlocked_ioctl: maybe_fn(T::HAS_IOCTL, fops_ioctl::), > #[cfg(CONFIG_COMPAT)] > compat_ioctl: if T::HAS_COMPAT_IOCTL { > @@ -216,6 +228,31 @@ impl VtableHelper { > 0 > } > > +/// # Safety > +/// > +/// `file` must be a valid file that is associated with a `MiscDeviceRegistration`. > +/// `vma` must be a vma that is currently being mmap'ed with this file. > +unsafe extern "C" fn fops_mmap( > + file: *mut bindings::file, > + vma: *mut bindings::vm_area_struct, > +) -> c_int { > + // SAFETY: The mmap call of a file can access the private data. > + let private = unsafe { (*file).private_data }; > + // SAFETY: Mmap calls can borrow the private data of the file. This safety comment seems unrelated to the safety requirements of `ForeignOwnable::borrow`. Best regards, Andreas Hindborg