From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from vps0.lunn.ch (vps0.lunn.ch [156.67.10.101]) (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 3D9831EBA02; Fri, 31 Jan 2025 16:05:30 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=156.67.10.101 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1738339534; cv=none; b=ElPfmU2gA/3h8Prf1pQPQP0R8WhPNsQz/DoxNjdjap6b/p5SiW6TWCpCI4nAM2jrRGez2WPvng/5vAYZcVzcwvNEYUvPxH1K/I8bXMS9aejjiZaCgtGL+GSrN0ZwWhtLI48LQMRRiXNRm/TpPFou8kOuiGAN4JvhDiQD8MlNjOA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1738339534; c=relaxed/simple; bh=1omhRQmvSB/Qil1fK+3eh4SCjNKBsj0EYIu0AGn7V7Q=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=X2u6f1TLqHPaXVdfw1cDzONoEPgU29dovY5ndo72d4HuJ6zhIL6msN3dM795v3Xcf+kUmhy1y6ZW/tHkbjIlFqN1lkrcLeSIa9BLwOrCyn4CnFN7XQLdnq4eoeb/0WMhW1g/bGf6Y+hIPdX2DPJHI0XPO1j4HPZjd91byL0sVLc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=lunn.ch; spf=pass smtp.mailfrom=lunn.ch; dkim=pass (1024-bit key) header.d=lunn.ch header.i=@lunn.ch header.b=1MYRElUg; arc=none smtp.client-ip=156.67.10.101 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=lunn.ch Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=lunn.ch Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=lunn.ch header.i=@lunn.ch header.b="1MYRElUg" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lunn.ch; s=20171124; h=In-Reply-To:Content-Disposition:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:From:Sender:Reply-To:Subject: Date:Message-ID:To:Cc:MIME-Version:Content-Type:Content-Transfer-Encoding: Content-ID:Content-Description:Content-Disposition:In-Reply-To:References; bh=oiBjie/3ciEURIkZ+iLsXyNmqPRpB2PMG1wBn3Ax9Sg=; b=1MYRElUgqBxjWkVDqUZZxZcr+8 ONv5FvkVLHES1aKsbjZX2Pd8KJ1igu+ZChE//zmIzI6E/JJkxufl/3qydIO3GW+s2+WuTOOYnInRi gkcKLlHtiYE/pzVQaPZwXFtqUrpiJ7jKe7FEyyQZS7tr4nWqoZecl617/SEkPEaJIOQM=; Received: from andrew by vps0.lunn.ch with local (Exim 4.94.2) (envelope-from ) id 1tdtVv-009jXz-O6; Fri, 31 Jan 2025 17:05:03 +0100 Date: Fri, 31 Jan 2025 17:05:03 +0100 From: Andrew Lunn To: Christian Schrefl Cc: Arnd Bergmann , Miguel Ojeda , Alex Gaynor , Boqun Feng , Gary Guo , =?iso-8859-1?Q?Bj=F6rn?= Roy Baron , Benno Lossin , Andreas Hindborg , Alice Ryhl , Trevor Gross , Jonathan Corbet , Russell King , Rudraksha Gupta , Ard Biesheuvel , Geert Stappers , Jamie Cunliffe , Sven Van Asbroeck , rust-for-linux@vger.kernel.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org Subject: Re: [PATCH v3] arm: rust: Enable Rust support for ARMv7 Message-ID: <65da77f7-bbd4-4cbe-a06c-75f10a6ec4ce@lunn.ch> References: <20250123-rfl-arm32-v3-1-8f13623d42c5@gmail.com> Precedence: bulk X-Mailing-List: linux-doc@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: > To fix this Rust would have to provide a way to build the core > library without float support. I don't know if there is a plan > already to allow this. Floating point is banned within the kernel, except for in very narrow conditions, because the floating point registers are lazy saved on context switch. If the kernel uses the floating point registers, you can break user space in bad ways. I expect this has been discussed, since it is well known kernel restriction. Maybe go see what happened to that discussion within RfL? Andrew