From: "Arnd Bergmann" <arnd@arndb.de>
To: "Andrew Morton" <akpm@linux-foundation.org>,
"Alice Ryhl" <aliceryhl@google.com>
Cc: "Miguel Ojeda" <ojeda@kernel.org>,
"Matthew Wilcox" <willy@infradead.org>,
"Alexander Viro" <viro@zeniv.linux.org.uk>,
"Kees Cook" <keescook@chromium.org>,
"Alex Gaynor" <alex.gaynor@gmail.com>,
"Wedson Almeida Filho" <wedsonaf@gmail.com>,
"Boqun Feng" <boqun.feng@gmail.com>,
"Gary Guo" <gary@garyguo.net>,
"Björn Roy Baron" <bjorn3_gh@protonmail.com>,
"Benno Lossin" <benno.lossin@proton.me>,
"Andreas Hindborg" <a.hindborg@samsung.com>,
"Greg Kroah-Hartman" <gregkh@linuxfoundation.org>,
"Arve Hjønnevåg" <arve@android.com>,
"Todd Kjos" <tkjos@android.com>,
"Martijn Coenen" <maco@android.com>,
"Joel Fernandes" <joel@joelfernandes.org>,
"Carlos Llamas" <cmllamas@google.com>,
"Suren Baghdasaryan" <surenb@google.com>,
"Trevor Gross" <tmgross@umich.edu>,
linux-mm@kvack.org, linux-kernel@vger.kernel.org,
rust-for-linux@vger.kernel.org,
"Christian Brauner" <brauner@kernel.org>
Subject: Re: [PATCH v6 2/4] uaccess: always export _copy_[from|to]_user with CONFIG_RUST
Date: Wed, 15 May 2024 07:34:31 +0000 [thread overview]
Message-ID: <ace5ac5c-88d2-43be-9236-11d3913886b9@app.fastmail.com> (raw)
In-Reply-To: <20240514102757.b7034966a58e6cf44d75dc7d@linux-foundation.org>
On Tue, May 14, 2024, at 17:27, Andrew Morton wrote:
> On Thu, 18 Apr 2024 08:59:18 +0000 Alice Ryhl <aliceryhl@google.com> wrote:
>
>> From: Arnd Bergmann <arnd@arndb.de>
>>
>> Rust code needs to be able to access _copy_from_user and _copy_to_user
>> so that it can skip the check_copy_size check in cases where the length
>> is known at compile-time, mirroring the logic for when C code will skip
>> check_copy_size. To do this, we ensure that exported versions of these
>> methods are available when CONFIG_RUST is enabled.
>>
>> Alice has verified that this patch passes the CONFIG_TEST_USER_COPY test
>> on x86 using the Android cuttlefish emulator.
>>
>> ...
>>
>> -#ifdef INLINE_COPY_TO_USER
>> static inline __must_check unsigned long
>> -_copy_to_user(void __user *to, const void *from, unsigned long n)
>> +_inline_copy_to_user(void __user *to, const void *from, unsigned long n)
>> {
>
> I think it would be helpful to have some comments in here describing
> why we're doing this _inline_* thing. What problem is it avoiding?
How about
/*
* Architectures that #define INLINE_COPY_TO_USER use this function
* directly in the normal copy_to_user(), the other ones go through
* an extern _copy_to_user(), which expands the same code here.
* Rust code always uses the extern definition.
*/
Arnd
next prev parent reply other threads:[~2024-05-15 7:34 UTC|newest]
Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-04-18 8:59 [PATCH v6 0/4] Memory management patches needed by Rust Binder Alice Ryhl
2024-04-18 8:59 ` [PATCH v6 1/4] rust: uaccess: add userspace pointers Alice Ryhl
2024-04-19 17:11 ` Boqun Feng
2024-04-19 18:12 ` Alice Ryhl
2024-04-18 8:59 ` [PATCH v6 2/4] uaccess: always export _copy_[from|to]_user with CONFIG_RUST Alice Ryhl
2024-05-14 17:27 ` Andrew Morton
2024-05-15 7:34 ` Arnd Bergmann [this message]
2024-04-18 8:59 ` [PATCH v6 3/4] rust: uaccess: add typed accessors for userspace pointers Alice Ryhl
2024-04-18 13:01 ` Benno Lossin
2024-04-18 13:17 ` Alice Ryhl
2024-04-18 16:23 ` Benno Lossin
2024-04-18 17:19 ` Boqun Feng
2024-04-18 19:35 ` Alice Ryhl
2024-04-18 20:01 ` Boqun Feng
2024-04-18 17:52 ` Trevor Gross
2024-04-25 16:13 ` Gary Guo
2024-04-26 7:13 ` Alice Ryhl
2024-04-18 8:59 ` [PATCH v6 4/4] rust: add abstraction for `struct page` Alice Ryhl
2024-04-18 18:52 ` Boqun Feng
2024-04-18 22:08 ` Benno Lossin
2024-04-18 22:56 ` Boqun Feng
2024-04-18 23:04 ` Boqun Feng
2024-04-19 8:36 ` Benno Lossin
2024-04-19 17:23 ` Boqun Feng
2024-04-19 19:24 ` Benno Lossin
2024-04-19 19:35 ` Boqun Feng
2024-04-25 16:20 ` Gary Guo
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=ace5ac5c-88d2-43be-9236-11d3913886b9@app.fastmail.com \
--to=arnd@arndb.de \
--cc=a.hindborg@samsung.com \
--cc=akpm@linux-foundation.org \
--cc=alex.gaynor@gmail.com \
--cc=aliceryhl@google.com \
--cc=arve@android.com \
--cc=benno.lossin@proton.me \
--cc=bjorn3_gh@protonmail.com \
--cc=boqun.feng@gmail.com \
--cc=brauner@kernel.org \
--cc=cmllamas@google.com \
--cc=gary@garyguo.net \
--cc=gregkh@linuxfoundation.org \
--cc=joel@joelfernandes.org \
--cc=keescook@chromium.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=maco@android.com \
--cc=ojeda@kernel.org \
--cc=rust-for-linux@vger.kernel.org \
--cc=surenb@google.com \
--cc=tkjos@android.com \
--cc=tmgross@umich.edu \
--cc=viro@zeniv.linux.org.uk \
--cc=wedsonaf@gmail.com \
--cc=willy@infradead.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).