From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mout02.posteo.de (mout02.posteo.de [185.67.36.66]) (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 8AAAB37BE96 for ; Sun, 6 Sep 2026 15:55:39 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=185.67.36.66 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788710141; cv=none; b=Bt7rVlA5FIzqMY3QUhCHCUujH+LlPg8sDI9d0PC9C0/O0GIEWuLTGSxuFk9K94MpBI6q4dejXg8hYZl3rqmPmclY0Xy8QNt89fyc4JPADdDXQBqZQ9q8IytfxfRpEO5hcVyAHlahONY9xoRm2QuktwswJ3AonAdmsHDMBWE3Yts= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788710141; c=relaxed/simple; bh=wWGgnov65ZJqhT9zXloo5ac7Dq5BL+le5LUIaHFssg4=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=rDeshGerh72Klo4LGWg3FMMz+teCsfFWJtbEe6vBL2jZ6XFh2I3u6iqhqzdX4jlNgFOr0Py/iiJnKb+MfxywiaR7iOvDGjfgLaIMD8keuhQMaZqQiWr5jt71uYiJHYdAt6a/ESYHnuqJYib/j4+vog03wV8N9/ai6IeIMMtvywU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=posteo.de; spf=pass smtp.mailfrom=posteo.de; dkim=pass (2048-bit key) header.d=posteo.de header.i=@posteo.de header.b=bgm+55n9; arc=none smtp.client-ip=185.67.36.66 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=posteo.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=posteo.de Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=posteo.de header.i=@posteo.de header.b="bgm+55n9" Received: from submission (posteo.de [185.67.36.169]) by mout02.posteo.de (Postfix) with ESMTPS id EDCDB240106 for ; Sun, 6 Sep 2026 17:55:37 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=posteo.de; s=1984.8680eb; t=1788710137; bh=H1usViq0rGSlCgRtIfdfxljYpLCz0O0luhM/wP/Mhdg=; h=From:Date:Subject:MIME-Version:Content-Type: Content-Transfer-Encoding:Message-Id:To:Cc:Autocrypt:OpenPGP:From; b=bgm+55n9kH9LwMUb/2gVuBS6Nn5vemQZL3dUWYX+J5kLqKKd1tYg8tqpLbIddwNs9 7yDqOl2iQobEsrK5jdMkhx62P8RxG9I6gt44V1tq66C1K2tsiNqOMhSmyerwNGO2Vx fAjpQcG0RyEHV1LUfV7iPO29Xao64Ba/nimX47Kq9A93S0aWaAT1rq/w5VTom69zLZ Q302V5Ok33dP0AjGD6DkQyDDbLQkzfOuXiczSNsQibbFbYGqvkLebHAvprre8FBXaV /c29nkWeAtWiCLcQcjXjQ3ZTSCiVPe8IDzrx16iXzBXuoiR0crn7hQsOmp/RoIsjTQ R2rP++8ZwMwUQ== Received: from customer (localhost [127.0.0.1]) by submission (posteo.de) with ESMTPSA id 4hdFCp2bqdz6tsg; Sun, 6 Sep 2026 17:55:34 +0200 (CEST) From: Markus Probst Date: Sun, 06 Sep 2026 15:55:35 +0000 Subject: [PATCH 5/5] rust: serdev: Pause receive callback before calling unbind Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Message-Id: <20260906-rust_serdev_probe_refactor-v1-5-69cdae0074ec@posteo.de> References: <20260906-rust_serdev_probe_refactor-v1-0-69cdae0074ec@posteo.de> In-Reply-To: <20260906-rust_serdev_probe_refactor-v1-0-69cdae0074ec@posteo.de> To: Ayush Singh , Johan Hovold , Alex Elder , Greg Kroah-Hartman , Miguel Ojeda , Boqun Feng , Gary Guo , =?utf-8?q?Bj=C3=B6rn_Roy_Baron?= , Benno Lossin , Andreas Hindborg , Alice Ryhl , Trevor Gross , Danilo Krummrich , Daniel Almeida , Tamir Duberstein , Alexandre Courbot , =?utf-8?q?Onur_=C3=96zkan?= , Eric Biggers , Ard Biesheuvel , Lorenzo Stoakes , Vlastimil Babka , "Liam R. Howlett" , Uladzislau Rezki , Jiri Slaby , "Rafael J. Wysocki" Cc: greybus-dev@lists.linaro.org, linux-serial@vger.kernel.org, rust-for-linux@vger.kernel.org, linux-kernel@vger.kernel.org, driver-core@lists.linux.dev, Markus Probst X-Developer-Signature: v=1; a=openpgp-sha256; l=5586; i=markus.probst@posteo.de; h=from:subject:message-id; bh=wWGgnov65ZJqhT9zXloo5ac7Dq5BL+le5LUIaHFssg4=; b=owEBiQJ2/ZANAwAIATR2H/jnrUPSAcsmYgBqnYzqL9li5x5gN5EmZDfiI0wa3kL6wZcVpyvy8 juxF/4VPwqJAk8EAAEIADkWIQSCdBjE9KxY53IwxHM0dh/4561D0gUCap2M6hsUgAAAAAAEAA5t YW51MiwyLjUrMS4xMiwyLDIACgkQNHYf+OetQ9LwtA//UxEEr+R22CvNQ3VHemKSdgP9TSGAQkO q0Fu8+es04maTv2GQDc4cEJUvpg+slftg49jOL2z2hzQixFpWgQMyf71F027p3uyRKbAFId5cNo QgP9fRgr8U7vDm9FVQi0YNMUpYlCvf8sQIH+unPw5x1cMeEyF1KYmG4Ry+IOVjrGEhiwzsCg7Hp 5cbNXKIjT+UiHAzgmHwM/4mpJE9aMSIxx8FNeE6sEb665hwifvBfGsbZB+hF5+2bX/Q3zXldTik v/0pVNV97HuR6QJf1wGSOJP1sol5HskQNlWjMZ9hqNlQ88EPNsbMsCQ9ExHNBCzvos8xytgCJVs rhk4uQXof5i4lbtaoSuYnImIfyhDM4H3aG3wzU1hHQFoxhvsFaR/sqjoEDWHdphCvT9YX+kPFyk RKfFJszptzwz6A/eN6Tv9L4TgUfP+uRBbP+tqOlunSSsMl/XlYyzb7iL+jzkJd8yzVhjlOGdPLV R/UhzBgX/k72IDh1g0UwuOsja907ZhDOFq8ruzCVnFJDrsVizhddQZiGyUjxDmDiNgo2rzwZPTX nBblJ/7sUkkkijuzDJwnO9ZjRHVQDR5crDQayVp7uabUtvgL3Ls9r6iKOIZSudtWv3rUuWTcXYM s88TsqVKJ729ZnEvubvLfeCoUwOtjhAMZyuZxW53GLUCI6OqqizQ= X-Developer-Key: i=markus.probst@posteo.de; a=openpgp; fpr=827418C4F4AC58E77230C47334761FF8E7AD43D2 Autocrypt: addr=markus.probst@posteo.de; prefer-encrypt=mutual; keydata=xsFNBGiDvXgBEADAXUceKafpl46S35UmDh2wRvvx+UfZbcTjeQOlSwKP7YVJ4JOZrVs93qReNLkO WguIqPBxR9blQ4nyYrqSCV+MMw/3ifyXIm6Pw2YRUDg+WTEOjTixRCoWDgUj1nOsvJ9tVAm76Ww+ /pAnepVRafMID0rqEfD9oGv1YrfpeFJhyE2zUw3SyyNLIKWD6QeLRhKQRbSnsXhGLFBXCqt9k5JA RhgQof9zvztcCVlT5KVvuyfC4H+HzeGmu9201BVyihJwKdcKPq+n/aY5FUVxNTgtI9f8wIbmfAja oT1pjXSp+dszakA98fhONM98pOq723o/1ZGMZukyXFfsDGtA3BB79HoopHKujLGWAGskzClwTjRQ xBqxh/U/lL1pc+0xPWikTNCmtziCOvv0KA0arDOMQlyFvImzX6oGVgE4ksKQYbMZ3Ikw6L1Rv1J+ FvN0aNwOKgL2ztBRYscUGcQvA0Zo1fGCAn/BLEJvQYShWKeKqjyncVGoXFsz2AcuFKe1pwETSsN6 OZncjy32e4ktgs07cWBfx0v62b8md36jau+B6RVnnodaA8++oXl3FRwiEW8XfXWIjy4umIv93tb8 8ekYsfOfWkTSewZYXGoqe4RtK80ulMHb/dh2FZQIFyRdN4HOmB4FYO5sEYFr9YjHLmDkrUgNodJC XCeMe4BO4iaxUQARAQABzRdtYXJrdXMucHJvYnN0QHBvc3Rlby5kZcLBkQQTAQgAOxYhBIJ0GMT0 rFjncjDEczR2H/jnrUPSBQJog714AhsDBQsJCAcCAiICBhUKCQgLAgQWAgMBAh4HAheAAAoJEDR2 H/jnrUPSgdkQAISaTk2D345ehXEkn5z2yUEjaVjHIE7ziqRaOgn/QanCgeTUinIv6L6QXUFvvIfH 1OLPwQ1hfvEg9NnNLyFezWSy6jvoVBTIPqicD/r3FkithnQ1IDkdSjrarPMxJkvuh3l7XZHo49GV HQ8i5zh5w4YISrcEtE99lJisvni2Jqx7we5tey9voQFDyM8jxlSWv3pmoUTCtBkX/eKHJXosgsuS B4TGDCVPOjla/emI5c9MhMG7O4WEEmoSdPbmraPw66YZD6uLyhV4DPHbiDWRzXWnClHSyjB9rky9 lausFxogvu4l9H+KDsXIadNDWdLdu1/enS/wDd9zh5S78rY2jeXaG4mnf4seEKamZ7KQ6FIHrcyP ezdDzssPQcTQcGRMQzCn6wP3tlGk7rsfmyHMlFqdRoNNv+ZER/OkmZFPW655zRfbMi0vtrqK2Awm 9ggobb1oktfd9PPNXMUY+DNVlgR2G7jLnenSoQausLUm0pHoNE8TWFv851Y6SOYnvn488sP1Tki5 F3rKwclawQFHUXTCQw+QSh9ay8xgnNZfH+u9NY7w3gPoeKBOAFcBc2BtzcgekeWS8qgEmm2/oNFV G0ivPQbRx8FjRKbuF7g3YhgNZZ0ac8FneuUtJ2PkSIFTZhaAiC0utvxk0ndmWFiW4acEkMZGrLaM L2zWNjrqwsD2zsFNBGiDvXgBEADCXQy1n7wjRxG12DOVADawjghKcG+5LtEf31WftHKLFbp/HArj BhkT6mj+CCI1ClqY+FYU5CK/s0ScMfLxRGLZ0Ktzawb78vOgBVFT3yB1yWBTewsAXdqNqRooaUNo 8cG/NNJLjhccH/7PO/FWX5qftOVUJ/AIsAhKQJ18Tc8Ik73v427EDxuKb9mTAnYQFA3Ev3hAiVbO 6Rv39amVOfJ8sqwiSUGidj2Fctg2aB5JbeMln0KCUbTD1LhEFepeKypfofAXQbGwaCjAhmkWy/q3 IT1mUrPxOngbxdRoOx1tGUC0HCMUW1sFaJgQPMmDcR0JGPOpgsKnitsSnN7ShcCr1buel7vLnUMD +TAZ5opdoF6HjAvAnBQaijtK6minkrM0seNXnCg0KkV8xhMNa6zCs1rq4GgjNLJue2EmuyHooHA4 7JMoLVHcxVeuNTp6K2+XRx0Pk4e2Lj8IVy9yEYyrywEOC5XRW37KJjsiOAsumi1rkvM7QREWgUDe Xs0+RpxI3QrrANh71fLMRo7LKRF3Gvw13NVCCC9ea20P4PwhgWKStkwO2NO+YJsAoS1QycMi/vKu 0EHhknYXamaSV50oZzHKmX56vEeJHTcngrM8R1SwJCYopCx9gkz90bTVYlitJa5hloWTYeMD7FNj Y6jfVSzgM/K4gMgUNDW/PPGeMwARAQABwsF2BBgBCAAgFiEEgnQYxPSsWOdyMMRzNHYf+OetQ9IF AmiDvXgCGwwACgkQNHYf+OetQ9LHDBAAhk+ab8+WrbS/b1/gYW3q1KDiXU719nCtfkUVXKidW5Ec Idlr5HGt8ilLoxSWT2Zi368iHCXS0WenGgPwlv8ifvB7TOZiiTDZROZkXjEBmU4nYjJ7GymawpWv oQwjMsPuq6ysbzWtOZ7eILx7cI0FjQeJ/Q2baRJub0uAZNwBOxCkAS6lpk5Fntd2u8CWmDQo4SYp xeuQ+pwkp0yEP30RhN2BO2DXiBEGSZSYh+ioGbCHQPIV3iVj0h6lcCPOqopZqyeCfigeacBI0nvN jHWz/spzF3+4OS+3RJvoHtAQmProxyGib8iVsTxgZO3UUi4TSODeEt0i0kHSPY4sCciOyXfAyYoD DFqhRjOEwBBxhr+scU4C1T2AflozvDwq3VSONjrKJUkhd8+WsdXxMdPFgBQuiKKwUy11mz6KQfcR wmDehF3UaUoxa+YIhWPbKmycxuX/D8SvnqavzAeAL1OcRbEI/HsoroVlEFbBRNBZLJUlnTPs8ZcU 4+8rq5YX1GUrJL3jf6SAfSgO7UdkEET3PdcKFYtS+ruV1Cp5V0q4kCfI5jk25iiz8grM2wOzVSsc l1mEkhiEPH87HP0whhb544iioSnumd3HJKL7dzhRegsMizatupp8D65A2JziW0WKopa1iw9fti3A aBeNN4ijKZchBXHPgVx+YtWRHfcm4l8= OpenPGP: url=https://posteo.de/keys/markus.probst@posteo.de.asc; preference=encrypt The receive callback and unbind callback now have exclusive access to the drivers private data. Provide mutable references in callbacks to avoid the need for locks in the private data. Remove the Sync requirement. Signed-off-by: Markus Probst --- rust/kernel/serdev.rs | 39 ++++++++++++++++++++++---------------- samples/rust/rust_driver_serdev.rs | 2 +- 2 files changed, 24 insertions(+), 17 deletions(-) diff --git a/rust/kernel/serdev.rs b/rust/kernel/serdev.rs index 66543108ec2f..7d47d91e3bc3 100644 --- a/rust/kernel/serdev.rs +++ b/rust/kernel/serdev.rs @@ -111,12 +111,12 @@ pub struct PrivateData<'bound, T: Driver> { } impl<'bound, T: Driver> PrivateData<'bound, T> { - fn driver_data(self: Pin<&Self>) -> Pin<&T::Data<'bound>> { + fn driver_data(self: Pin<&mut Self>) -> Pin<&mut T::Data<'bound>> { // SAFETY: We treat the result as pinned. let inner = unsafe { Pin::into_inner_unchecked(self) }; // SAFETY: `self.driver` is pinned. - unsafe { Pin::new_unchecked(&inner.driver) } + unsafe { Pin::new_unchecked(&mut inner.driver) } } } @@ -175,15 +175,18 @@ extern "C" fn remove_callback(sdev: *mut bindings::serdev_device) { // INVARIANT: `sdev` is valid for the duration of `remove_callback()`. let sdev = unsafe { &*sdev.cast::>>() }; - // SAFETY: `remove_callback` is only ever called after a successful call to - // `probe_callback`, hence it's guaranteed that `Device::set_drvdata()` has been called - // and stored a `Pin>>`. - let private_data = unsafe { sdev.as_ref().drvdata_borrow::>() }; - - T::unbind(sdev, private_data.driver_data()); - // SAFETY: `sdev.as_raw()` is guaranteed to be a valid pointer to `serdev_device`. unsafe { bindings::serdev_device_pause_rx(sdev.as_raw()) }; + + // SAFETY: + // - `remove_callback` is only ever called after a successful call to `probe_callback`, + // hence it's guaranteed that `Device::set_drvdata()` has been called and stored a + // `Pin>>`. + // - The call to `serdev_device_pause_rx` above guarantees that we do not overlap with + // `receive_buf_callback`, thus it is guaranteed that we have exclusive access. + let private_data = unsafe { sdev.as_ref().drvdata_borrow_mut::>() }; + + T::unbind(sdev, private_data.driver_data()); } extern "C" fn receive_buf_callback( @@ -200,10 +203,14 @@ extern "C" fn receive_buf_callback( // INVARIANT: `sdev` is valid for the duration of `receive_buf_callback()`. let sdev = unsafe { &*sdev.cast::>() }; - // SAFETY: `receive_buf_callback` is only ever called after a successful call to - // `probe_callback`, hence it's guaranteed that `Device::set_drvdata()` has been called - // and stored a `Pin>>`. - let private_data = unsafe { sdev.as_ref().drvdata_borrow::>() }; + // SAFETY: + // - `receive_buf_callback` is only ever called after a successful call to `probe_callback`, + // hence it's guaranteed that `Device::set_drvdata()` has been called and stored a + // `Pin>>`. + // - `unbind_callback` calls `serdev_device_pause_rx` before accessing the driver data, + // which guarantees that this function will not overlap with it. Thus we have exclusive + // access. + let private_data = unsafe { sdev.as_ref().drvdata_borrow_mut::>() }; T::receive(sdev, private_data.driver_data(), buf) } @@ -305,7 +312,7 @@ pub trait Driver { type IdInfo: 'static; /// The type of the driver's bus device private data. - type Data<'bound>: Send + Sync + 'bound; + type Data<'bound>: Send + 'bound; /// The table of OF device ids supported by the driver. const OF_ID_TABLE: Option> = None; @@ -331,7 +338,7 @@ fn probe<'bound>( /// `&Device` or `&Device` reference. For instance. /// /// Otherwise, release operations for driver resources should be performed in `Drop`. - fn unbind<'bound>(sdev: &'bound Device>, this: Pin<&Self::Data<'bound>>) { + fn unbind<'bound>(sdev: &'bound Device>, this: Pin<&mut Self::Data<'bound>>) { let _ = (sdev, this); } @@ -342,7 +349,7 @@ fn unbind<'bound>(sdev: &'bound Device>, this: Pin<&Self::Data< /// Returns the number of bytes accepted. fn receive<'bound>( sdev: &'bound Device, - this: Pin<&Self::Data<'bound>>, + this: Pin<&mut Self::Data<'bound>>, data: &[u8], ) -> usize { let _ = (sdev, this, data); diff --git a/samples/rust/rust_driver_serdev.rs b/samples/rust/rust_driver_serdev.rs index 51b4898cd855..d00d547234c8 100644 --- a/samples/rust/rust_driver_serdev.rs +++ b/samples/rust/rust_driver_serdev.rs @@ -63,7 +63,7 @@ fn probe<'bound>( fn receive<'bound>( sdev: &'bound serdev::Device, - _this: Pin<&Self>, + _this: Pin<&mut Self>, data: &[u8], ) -> usize { sdev.write(data).unwrap_or_default() as usize -- 2.55.0