From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 EEE4824886A; Sat, 14 Mar 2026 11:53:25 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1773489206; cv=none; b=Kf2amFLFXub744dipMrEobNm3F3Ifg9+lYMMflK0CHcxhSGO2ISB5TgZXG2cOuUDKE/jzOY/r45xxo9e6Ndohi1npufA+Mplnz56QL6K/HsceUFQjkjotAnqMJ3++vShNKM55An2fa0DS4Y44jeY2JZC9ie6URHbR5nePSTXL+c= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1773489206; c=relaxed/simple; bh=impwRFcDkworY8zCZmfr/pzhhIFp1qkfw4v11OePyXs=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=F+YW7RnUyysp4rh4dWXzmHFbuiTE3qY/32t3FiaVSPIMoyTEsaUS4qB1g9Dzb5gxgnpV1iw4pa5CrWlohel9xdsv/B9dwRTrxO66SWG31QnUSy9LV3VMJE2m5bwFmKNmwWYC/IJFEKTLSglYFb0vegKHD2RslfATeVgCz3kW5Zw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=OPyUbzFT; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="OPyUbzFT" Received: by smtp.kernel.org (Postfix) with ESMTPSA id C5D60C116C6; Sat, 14 Mar 2026 11:53:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1773489205; bh=impwRFcDkworY8zCZmfr/pzhhIFp1qkfw4v11OePyXs=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=OPyUbzFTYoslL0P3QB9MBfwljyZslpNJOVMS9ZCSePNL1wdK8CBYrpW9E2gmT29a5 UpZVqYoJGdwSkQZsEmqZb+9M47K9Bu6m6pRwNneUh0NTPtg1EOV7iE5WOMfLUFVbaS 7QETJzTuQxufPloRfVYb7h3yyTx0SzXq4ib0fpWU= Date: Sat, 14 Mar 2026 12:53:21 +0100 From: Greg Kroah-Hartman To: Alice Ryhl Cc: Miguel Ojeda , Nathan Chancellor , Mike Rapoport , kernel test robot , Andrew Morton , llvm@lists.linux.dev, oe-kbuild-all@lists.linux.dev, Linux Memory Management List , Mark Brown , rust-for-linux@vger.kernel.org, Miguel Ojeda , Danilo Krummrich , Jann Horn , "Liam R. Howlett" Subject: Re: [linux-next:master 5585/5731] error[E0277]: `*const kernel::bindings::vm_uffd_ops` cannot be shared between threads safely Message-ID: <2026031444-wriggle-tradition-245f@gregkh> References: <202603121235.tpnRxFKO-lkp@intel.com> <20260313213638.GA147391@ax162> <2026031422-catsup-rectal-f886@gregkh> Precedence: bulk X-Mailing-List: llvm@lists.linux.dev 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 Sat, Mar 14, 2026 at 11:30:24AM +0000, Alice Ryhl wrote: > On Sat, Mar 14, 2026 at 12:15:30PM +0100, Alice Ryhl wrote: > > On Sat, Mar 14, 2026 at 12:13 PM Greg Kroah-Hartman > > wrote: > > > > > > On Fri, Mar 13, 2026 at 11:39:14PM +0100, Miguel Ojeda wrote: > > > > On Fri, Mar 13, 2026 at 10:36 PM Nathan Chancellor wrote: > > > > > > > > > > It looks like this is a conflict between Alice's "rust_binder: check ownership > > > > > before using vma" [1] (currently in char-misc-linus [2]) and Mike's > > > > > "userfaultfd: introduce vm_uffd_ops" [3] (currently in mm-unstable [4]), > > > > > hence why it was bisected to the -next merge commit. > > > > > > > > Thanks Nathan, yeah, adding a raw pointer (not function pointer) to > > > > the struct makes the type `!Sync` in Rust. > > > > > > > > I assume this is best handled with a patch on top of char-misc-linus. > > > > Perhaps creating a wrapper to assert it is `Sync`, since the > > > > `BINDER_VM_OPS` contents are unused (so far). > > > > > > > > Cc'ing more folks related to the commit. > > > > > > char-misc-linus should get merged into Linus's tree "soon" and then we > > > can fix up the mm-unstable change for this. > > > > I'm working on the fix as we speak. It would be ideal if it went into > > char-misc-linus, because the commit that is wrong is mine, not the one > > in mm. > > To clarify, to avoid breaking bisection, the commit needs to land > somewhere that is on top of commit 8ef2c15aeae0 ("rust_binder: check > ownership before using vma"), and before the mm commit. But I guess > there are several options for how to do that other than landing it > through char-misc-linus right now. I've sent off a pull request for the char-misc-linus branch now, and after -rc4 is out I'll queue this up on top of that to get merged for -rc5 to make this all work out ok. thanks, greg k-h