From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from pandora.armlinux.org.uk (pandora.armlinux.org.uk [78.32.30.218]) (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 0DC0F37BE66; Mon, 23 Mar 2026 10:03:50 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=78.32.30.218 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774260232; cv=none; b=Rm6uQn0pet2LEQ+WtPsWloV8vPYlj8EIim4bdOqi+C/wBHvj9r2XbZ21Rkh5KJGZuIUmzVYURPSzwgBwAKClvzBtU/o5gPbxJVeYtgLETKjUb4bqjZaBeCRctYvWPGSDDB6t4XptRJUnVNuyBr4oWRYxYWeMhl1qm9FPtZYT+Vo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774260232; c=relaxed/simple; bh=xro7tl4zvQyJrRWdcW7R6YorirXJvSVqLPErH59zAT8=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=X6YkiVhJRukVIitbtAVqvMaEe9bbwn2fEw1wcQNw5OELkQPeA8Nxdut7L3ZxIg6Ebl5I/ss3gKV9FjC0omiq9e5zkiqBn9wm7pUXIM/TQd/S2KlI84ynV7PzjIFBJgYsGw7uDnDCPXd9y/+RIrlKg8W4qb7H1cQWSJoqK8W37mU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=armlinux.org.uk; spf=none smtp.mailfrom=armlinux.org.uk; dkim=pass (2048-bit key) header.d=armlinux.org.uk header.i=@armlinux.org.uk header.b=0YF0Xiuw; arc=none smtp.client-ip=78.32.30.218 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=armlinux.org.uk Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=armlinux.org.uk Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=armlinux.org.uk header.i=@armlinux.org.uk header.b="0YF0Xiuw" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=armlinux.org.uk; s=pandora-2019; h=Sender:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id: List-Help:List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=Cz+j7B7EZWXqL1NEdjNkb8+tqvgFwGtEmQlc0a4uF/I=; b=0YF0XiuwT3u8tR4oPMYWEV/KFK H9fwrg4T/+n+RJ03PpS/Fav/FeJLLU7KVNxg/rC1jqK+w+LeTgzBtMY5uSRpKHO0wDv+X6cxP7NiC m75SRUqkIW5e3TcIYnU2V/9uxpyA8Sc/j0NWipcGGGzkIgVZX5Q+p4QRq+XPer8SHbcl8QxCKLAjM +YmYDZJz5gc2FBjWWOLytVpK4pbu5cpv+VXUz3RUGr/wvAMjrH6Zo5aYlwvQ2q7xNgwDr/8QYZiUW W9lgLx+4dBjuEbKoTDvDCm6znHsF6AcsyhR8Ua14v4nYL8zIAC5TUrwz1CHT9EOJzgzdxIrCwHslC 8tWM9ivQ==; Received: from shell.armlinux.org.uk ([fd8f:7570:feb6:1:5054:ff:fe00:4ec]:45792) by pandora.armlinux.org.uk with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.98.2) (envelope-from ) id 1w4c8C-000000000IN-2POJ; Mon, 23 Mar 2026 10:03:32 +0000 Received: from linux by shell.armlinux.org.uk with local (Exim 4.98.2) (envelope-from ) id 1w4c86-000000003wH-1o0a; Mon, 23 Mar 2026 10:03:26 +0000 Date: Mon, 23 Mar 2026 10:03:26 +0000 From: "Russell King (Oracle)" To: Miguel Ojeda Cc: a.hindborg@kernel.org, acourbot@nvidia.com, akpm@linux-foundation.org, aliceryhl@google.com, anton.ivanov@cambridgegreys.com, bjorn3_gh@protonmail.com, boqun.feng@gmail.com, dakr@kernel.org, david@davidgow.net, gary@garyguo.net, johannes@sipsolutions.net, justinstitt@google.com, linux-arm-kernel@lists.infradead.org, linux-kbuild@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-um@lists.infradead.org, llvm@lists.linux.dev, lossin@kernel.org, mark.rutland@arm.com, mmaurer@google.com, morbo@google.com, nathan@kernel.org, nick.desaulniers+lkml@gmail.com, nicolas.schier@linux.dev, nsc@kernel.org, peterz@infradead.org, richard@nod.at, rust-for-linux@vger.kernel.org, tmgross@umich.edu, urezki@gmail.com, will@kernel.org Subject: Re: Re: [PATCH v2 0/3] Inline helpers into Rust without full LTO Message-ID: References: <20260322192159.88138-1-ojeda@kernel.org> <20260323000327.111235-1-ojeda@kernel.org> 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=us-ascii Content-Disposition: inline In-Reply-To: <20260323000327.111235-1-ojeda@kernel.org> Sender: Russell King (Oracle) On Mon, Mar 23, 2026 at 01:03:27AM +0100, Miguel Ojeda wrote: > On Sun, 22 Mar 2026 20:21:59 +0100 Miguel Ojeda wrote: > > > > On the other hand, regardless of whether we fix this (and another > > issue in a separate email found thanks to the UML build), we could > > instead add `depends on` listing explicitly the architectures where > > this is going to be actually tested. That way maintainers can decide > > whether they want to support it when they are ready. Thoughts? > > Another one for arm 32-bit: > > LD .tmp_vmlinux1 > ld.lld: error: undefined symbol: __aeabi_read_tp > >>> referenced by uaccess.rs:349 (rust/kernel/uaccess.rs:349) > >>> samples/rust/rust_misc_device.o:(::ioctl) in archive vmlinux.a > >>> referenced by uaccess.rs:543 (rust/kernel/uaccess.rs:543) > >>> samples/rust/rust_misc_device.o:(::ioctl) in archive vmlinux.a > >>> referenced by uaccess.rs:543 (rust/kernel/uaccess.rs:543) > >>> drivers/android/binder/rust_binder_main.o:(rust_binder_main::rust_binder_ioctl) in archive vmlinux.a > >>> referenced 36 more times Why is Rust generating code for userspace thread accessors for kernel space, where userspace threads are meaningless. This is totally wrong. The kernel must not reference __aeabi_read_tp(). Note: I know nothing about Rust, but I know enough to say the above is pointing to a fundamental issue in Rust for 32-bit ARM. -- RMK's Patch system: https://www.armlinux.org.uk/developer/patches/ FTTP is here! 80Mbps down 10Mbps up. Decent connectivity at last!