From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 92EF9284B37 for ; Tue, 25 Aug 2026 11:09:01 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787656145; cv=none; b=GlKN4cQvR6NwH2d+YMBjHPZy/2fgOtpIzq5eqo0jXH3eOLH8GUNg9usU+1VsatO/A9C7rf7Ib6fhg2Uh3yLjHfBIk89fokXrBGX/dOXtZctfy4Sf3MLqzbZPOc0pqEeLFRqOocy/BJs+bZY8/mAB5y1spCLWx+FTWr5epDT9WaA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787656145; c=relaxed/simple; bh=0ciZa7SraEvE+4oulKgD9LnvfBVa+xK2+fvNvLgXDoY=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=WVjUl1TVP3xXMocJrq7R65CIsfTXnHZCXxSZhGWIAan+89j3VS7OuulLerc3wSCEF6KbEofQJxPjNyC9Z5QvejMWHf2qHb2qCO1c4zxZHCCR2Rt/McZ+BNOSL6xLTjDlccCTGywPv1L+Qkn0cwj7JDOZqP6JD5eZYNHfecf2GwM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=H/29TpN6; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="H/29TpN6" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 325441F00A3A; Tue, 25 Aug 2026 11:08:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1787656141; bh=bnmb0aePC2tHNSUsnpnWsxsGfEY0uUaaLGYqa9DfC4Y=; h=Date:From:To:Cc:Subject:References:In-Reply-To; b=H/29TpN6u2Hr02xBZz1Dvl7+9zSCbd8zdCTcBnTdJVVUiDdMk2d+JaTNU/g9gYc/8 zVJkXRb7ksdIZZKr89GLHHxGJiiwVZiru4eFSQIGqGuKMO4/CtKyKsJpRrTak2Y7Z7 C1ujJgaNh33OHd2jLuaiRmwnUhYjCshPIV7exj4w= Date: Tue, 25 Aug 2026 13:08:55 +0200 From: Greg KH To: Miguel Ojeda Cc: rust-for-linux@vger.kernel.org, Alice Ryhl , Gary Guo , Alvin Sun Subject: Re: merge problems with char-misc-next and Linus's branch right now Message-ID: <2026082514-such-version-4236@gregkh> References: <2026082516-slapstick-nearly-8986@gregkh> <1d80b800-8216-4731-830b-bbf055ab6e6f@linux.dev> Precedence: bulk X-Mailing-List: rust-for-linux@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: On Tue, Aug 25, 2026 at 12:49:54PM +0200, Miguel Ojeda wrote: > On Tue, Aug 25, 2026 at 12:05 PM Alvin Sun wrote: > > > > Gary has already posted a fix: > > https://lore.kernel.org/rust-for-linux/20260813163951.1102583-1-gary@kernel.org/ > > Yeah, please see as well the other conflicts related to char-misc this cycle: > > https://lore.kernel.org/linux-next/20260805-slab-rust-fix-v1-1-c4d4c1b69de2@kernel.org/ > > https://lore.kernel.org/linux-next/ans8lsGbkro4pO6N@sirena.org.uk/ > (the diff in that thread is from another conflict somehow, but the > actual conflict is very simple anyway) > > The resolutions in linux-next should be fine. > > My overall list of conflicts for Linus is at: > > https://lore.kernel.org/rust-for-linux/20260816191926.230123-1-ojeda@kernel.org/ Yeah, it's messy. Below is my resolution, seems to work here for me and I'll send it along to Linus as well. thanks, greg k-h diff --cc rust/kernel/sync/poll.rs index 5aa0ce9ba01b,684dfa242b1a..000000000000 --- a/rust/kernel/sync/poll.rs +++ b/rust/kernel/sync/poll.rs @@@ -8,13 -9,14 +9,18 @@@ use crate:: bindings, fs::File, prelude::*, - sync::{CondVar, LockClassKey}, + sync::{ + rcu::synchronize_rcu, + CondVar, + LockClassKey, // + }, // + types::Opaque, // + }; + use core::{ + marker::PhantomData, + mem::ManuallyDrop, + ops::Deref, // }; - use core::{marker::PhantomData, ops::Deref}; /// Creates a [`PollCondVar`] initialiser with the given name and a newly-created lock class. #[macro_export] @@@ -103,6 -106,72 +110,70 @@@ impl PinnedDrop for PollCondVar unsafe { bindings::__wake_up_pollfree(self.inner.wait_queue_head.get()) }; // Wait for epoll items to be properly removed. - // - // SAFETY: Just an FFI call. - unsafe { bindings::synchronize_rcu() }; + synchronize_rcu(); } } + + /// A [`KBox`] that uses `kfree_rcu`. + /// + /// [`KBox`]: PollCondVar + pub struct PollCondVarBox { + inner: ManuallyDrop>>, + } + + #[pin_data] + #[repr(C)] + struct PollCondVarBoxInner { + #[pin] + inner: PollCondVar, - rcu: Opaque, ++ rcu: Opaque, + } + + // SAFETY: PollCondVar is Send + unsafe impl Send for PollCondVarBoxInner {} + // SAFETY: PollCondVar is Sync + unsafe impl Sync for PollCondVarBoxInner {} + + impl PollCondVarBox { + /// Constructs a new boxed [`PollCondVar`]. + pub fn new(name: &'static CStr, key: Pin<&'static LockClassKey>) -> Result { + let b = KBox::pin_init( + pin_init!(PollCondVarBoxInner { + inner <- PollCondVar::new(name, key), + rcu: Opaque::uninit(), + }), + GFP_KERNEL, + ) + .map_err(|_| AllocError)?; + + Ok(PollCondVarBox { + inner: ManuallyDrop::new(b), + }) + } + } + + impl Deref for PollCondVarBox { + type Target = PollCondVar; + fn deref(&self) -> &PollCondVar { + &self.inner.inner + } + } + + impl Drop for PollCondVarBox { + #[inline] + fn drop(&mut self) { + // SAFETY: ManuallyDrop::take ok because not already taken. + let boxed = unsafe { ManuallyDrop::take(&mut self.inner) }; + + // SAFETY: The code below frees the box without calling the actual destructor of the type, + // but it's okay because it re-implements the destructor using `kfree_rcu()` in place of + // `synchronize_rcu()`. + let ptr = KBox::into_raw(unsafe { Pin::into_inner_unchecked(boxed) }); + + // SAFETY: The pointer points at a valid `wait_queue_head`. + unsafe { bindings::__wake_up_pollfree((*ptr).inner.inner.wait_queue_head.get()) }; + + // SAFETY: This was allocated using `KBox::pin_init`, so it can be freed with `kvfree`. + unsafe { bindings::kvfree_call_rcu((*ptr).rcu.get(), ptr.cast::()) }; + } + } diff --cc rust/kernel/task.rs index c2b3457b700c,1b290c61714d..000000000000 --- a/rust/kernel/task.rs +++ b/rust/kernel/task.rs @@@ -210,7 -210,14 +210,14 @@@ impl Task unsafe { *ptr::addr_of!((*self.as_ptr()).pid) } } + /// Returns the TGID (Thread Group ID / Process ID) of the given task. + pub fn tgid(&self) -> Pid { + // SAFETY: The tgid of a task never changes after initialization, so reading this field is + // not a data race. + unsafe { *ptr::addr_of!((*self.as_ptr()).tgid) } + } + - /// Returns the UID of the given task. + /// Returns the objective real UID of the given task. #[inline] pub fn uid(&self) -> Kuid { // SAFETY: It's always safe to call `task_uid` on a valid task. diff --cc rust/uapi/uapi_helper.h index 1c4aa4292dce,86c7b6b284b0..000000000000 --- a/rust/uapi/uapi_helper.h +++ b/rust/uapi/uapi_helper.h @@@ -10,7 -11,7 +10,8 @@@ #include #include #include + #include +#include #include #include #include diff --git a/drivers/android/binder/netlink.rs b/drivers/android/binder/netlink.rs index beb7ea2edaff..f34e1009432c 100644 --- a/drivers/android/binder/netlink.rs +++ b/drivers/android/binder/netlink.rs @@ -13,7 +13,7 @@ }; pub static BINDER_NL_FAMILY: Family = Family::const_new( - &crate::THIS_MODULE, + kernel::module::this_module::(), kernel::uapi::BINDER_FAMILY_NAME, kernel::uapi::BINDER_FAMILY_VERSION, &BINDER_NL_FAMILY_MCGRPS, * Unmerged path drivers/misc/sgi-xp/xpc_uv.c