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 758B5E77180 for ; Mon, 16 Dec 2024 14:51:28 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 0B1EA6B009B; Mon, 16 Dec 2024 09:51:28 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 03A7E6B009C; Mon, 16 Dec 2024 09:51:27 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id DCE5B6B009D; Mon, 16 Dec 2024 09:51:27 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0013.hostedemail.com [216.40.44.13]) by kanga.kvack.org (Postfix) with ESMTP id BA9986B009B for ; Mon, 16 Dec 2024 09:51:27 -0500 (EST) Received: from smtpin01.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay06.hostedemail.com (Postfix) with ESMTP id 6D665AF851 for ; Mon, 16 Dec 2024 14:51:27 +0000 (UTC) X-FDA: 82901109228.01.910BAEB Received: from nyc.source.kernel.org (nyc.source.kernel.org [147.75.193.91]) by imf07.hostedemail.com (Postfix) with ESMTP id 23AF84000C for ; Mon, 16 Dec 2024 14:50:44 +0000 (UTC) Authentication-Results: imf07.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=hpZJl9b1; spf=pass (imf07.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=JO3eZbH/2b22svYx79HgLOaUUvTcdGhwSk/awE++sbk=; b=m26canQhNyWXqGEID/vaYsQO/7e9Zp4M874yFCYbDweNOflGvIUnVuhqiHb6VBhYvfQfqZ zFnum48JOKXvjJbnyTqt3d3qKj5DGiCNufhsqfC7Mu8nmiQI/Sm6o6+Vm7FF8y5H9HGtyW Vzko0kNiPQWM9jY0+jqQSsIQ+JDOBWU= ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1734360653; a=rsa-sha256; cv=none; b=ydTboKclVl9Py/Pp7oJGEw9gfzFrdaG1DfnPiWwT9I2u9yftpDhgtQ7r4TPn1Yg69elyKQ XLcQJAWH1xoQfZ0ls6itGxnkgJdvAjzb/I0shPuFNo6XMPhcGAe5H16IksD0C8akVY5H/W PXo5q6OobTzmeSEws7TKMkJey3sG2ng= ARC-Authentication-Results: i=1; imf07.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=hpZJl9b1; spf=pass (imf07.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 Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by nyc.source.kernel.org (Postfix) with ESMTP id 6EFA7A41774; Mon, 16 Dec 2024 14:49:34 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 2A682C4CED0; Mon, 16 Dec 2024 14:51:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1734360684; bh=VSQZ/AKwvf2LJcrZzL1IDApIqfRTSAFZpSCwFSSlC/w=; h=From:To:Cc:Subject:In-Reply-To:References:Date:From; b=hpZJl9b1YQB+3WKmUm0rX90tuDV8nxkw5nJZe7Clo2lj4LRzqvvUe4YDNJsoCBEWs zNUxpwjKfZTHighicJ246cMLpKHw8Gg6xBYUffQNizkYnjaLljZLEJq89WzMuXuFwL /Sss64Sp8cinXbnVMCg3Pz1r+tMH+FJcuq8vIW3DqbekSLqthiC17A4VGxNNjhCegQ 01jBku9es2bEHp/ElRFw+Vsmz3CeNL0hdZL3JeSrnsSJKXwGrCazsUJaSpOy6nKqw1 kJBOz32mcdjNs0D1Ek2vd4yJOgkgoP5amuCFe+NeXkEF4TS7RTNlqU92MXapcqrHnj 6p0cTs5yIWrOg== 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 6/8] mm: rust: add VmAreaNew for f_ops->mmap() In-Reply-To: <20241211-vma-v11-6-466640428fc3@google.com> (Alice Ryhl's message of "Wed, 11 Dec 2024 10:37:10 +0000") References: <20241211-vma-v11-0-466640428fc3@google.com> <20241211-vma-v11-6-466640428fc3@google.com> Date: Mon, 16 Dec 2024 14:41:00 +0100 Message-ID: <87o71bagpf.fsf@kernel.org> MIME-Version: 1.0 Content-Type: text/plain X-Rspamd-Queue-Id: 23AF84000C X-Rspam-User: X-Rspamd-Server: rspam07 X-Stat-Signature: 3sp4c8g34p4ar6thyih5xzd7j33ijkre X-HE-Tag: 1734360644-208057 X-HE-Meta: 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 5LB0SQ/J Btq7oPmHZIYPtgwoH3Q+zn5t6/643UEQcN9Hb0mHPfFY9dht57KKtYhYeCCgPX0x1nbo6UG6a5r/dLybFND5jLjbu+5CeguOaf7aKOAYD5+mOlzBJMIRqBWdEiZWxprZ5J5Mn/UnerfkTLF6oUgUx2GOTDTtWzxsztEM87R3t3MGyoZVpm+C/upJOvUFufT3/X8eb0O9/g6Ut9W0y2JUhllg0i5buh37xJGsJZwX7JYCMTpeBSCd7QhxTg/qv/Irt0eWTVCkvq6aARdBuW4xrH5p0teU3OHuoPl/73aU1XDFQcPE+HxcxkngPnaU2o9nQV/dUIst58GsWTxTd47dfFbmVfa1We+viyrXH4NDfos9stZW5WRqv1bTU9w== X-Bogosity: Ham, tests=bogofilter, spamicity=0.371073, 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: > This type will be used when setting up a new vma in an f_ops->mmap() > hook. Using a separate type from VmAreaRef allows us to have a separate > set of operations that you are only able to use during the mmap() hook. > For example, the VM_MIXEDMAP flag must not be changed after the initial > setup that happens during the f_ops->mmap() hook. > > To avoid setting invalid flag values, the methods for clearing > VM_MAYWRITE and similar involve a check of VM_WRITE, and return an error > if VM_WRITE is set. Trying to use `try_clear_maywrite` without checking > the return value results in a compilation error because the `Result` > type is marked #[must_use]. > > For now, there's only a method for VM_MIXEDMAP and not VM_PFNMAP. When > we add a VM_PFNMAP method, we will need some way to prevent you from > setting both VM_MIXEDMAP and VM_PFNMAP on the same vma. > > Acked-by: Lorenzo Stoakes (for mm bits) > Reviewed-by: Jann Horn > Signed-off-by: Alice Ryhl > --- > rust/kernel/mm/virt.rs | 181 ++++++++++++++++++++++++++++++++++++++++++++++++- > 1 file changed, 180 insertions(+), 1 deletion(-) > > diff --git a/rust/kernel/mm/virt.rs b/rust/kernel/mm/virt.rs > index 3a23854e14f4..6d9ba56d4f95 100644 > --- a/rust/kernel/mm/virt.rs > +++ b/rust/kernel/mm/virt.rs > @@ -6,7 +6,7 @@ > > use crate::{ > bindings, > - error::{to_result, Result}, > + error::{code::EINVAL, to_result, Result}, > mm::MmWithUser, > page::Page, > types::Opaque, > @@ -171,6 +171,185 @@ pub fn vm_insert_page(&self, address: usize, page: &Page) -> Result { > } > } > > +/// A builder for setting up a vma in an `f_ops->mmap()` hook. Reading this line, I would expect to be able to chain update methods as in `Builder::new().prop_a().prop_b().build()`. Could/should this type accommodate a proper builder pattern? Or is "builder" not the right word to use here? Best regards, Andreas Hindborg