From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from desiato.infradead.org (desiato.infradead.org [90.155.92.199]) (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 EBAA3302CD7; Wed, 22 Oct 2025 08:13:36 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=90.155.92.199 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1761120820; cv=none; b=rsS1EvC9fD2SMLU8lK0Y7QieiMGBOZ5bfhhKj60Rhyt39Fz7+j9wC+s5gNwGtOlrNAn4HUHsElIygBer3lDEGXfI/wkuS4Cm4uBeB6cno46JfHaHdVZlTcDKJKWrUT/ZBJDDMHPkVujl9Oq5UdApv06vMCWvsX9Jo1ofroEb1fE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1761120820; c=relaxed/simple; bh=wuFKp7wVKGv7PxIwB3wTcUJzK/cF02oGo1qGZ7cCaaI=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=PQQ2qN2BOOCQQATHEx2I0RBPO/j6JjeMBwRPznVpocfx81ZqQOAt2l8Sx6F+yzixBaGtJiVOh+AMyJ4VqfJK0qSggUSieQ0pYzmyc+O5LKmsSgZmKW5Au4aO8HJWe5kUKuMWPaH2zYJW6XWiC+Eq6WuCdiDHcuAIPjIm/PjZOV0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org; spf=none smtp.mailfrom=infradead.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b=GZ9DMzin; arc=none smtp.client-ip=90.155.92.199 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=infradead.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="GZ9DMzin" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=desiato.20200630; h=In-Reply-To:Content-Transfer-Encoding: Content-Type:MIME-Version:References:Message-ID:Subject:Cc:To:From:Date: Sender:Reply-To:Content-ID:Content-Description; bh=Dg1Y08ybKAYmv4kbw7GmgeGRx4rZ+X8n9sBGCrSRBGU=; b=GZ9DMzin4MAQCShxEKq7jllj2o 6G2s8ConHG8zGICW8cFsNhPES60m2FRMTyN2udlPNKEdsL6Xt9v+JfXLsehLQ7H2sMCJiLTeu9Gu8 LwhLniGAdCyoFmur++KfC/tEE9UqEPlqzuMjKGaL82B0ZpMk7PPDR+EJG28gQSSW4izCE4AQUjjVc 2MmybLPDgfmcV0+HsSnaD+42KinoeLAbT+yIWfvUVm5zRuUJGe6zDa4VM+DKN69xVz0xxaJsCCGzo UcY/VMdtWryQy+4K4udRQsCTwuf54j+Xd8kJa+u1uuEpguLFO2KTk2W72xdgJzNQpg8jkoUGXeviO IzUAcQzw==; Received: from 77-249-17-252.cable.dynamic.v4.ziggo.nl ([77.249.17.252] helo=noisy.programming.kicks-ass.net) by desiato.infradead.org with esmtpsa (Exim 4.98.2 #2 (Red Hat Linux)) id 1vBT6i-00000000Or0-0BCT; Wed, 22 Oct 2025 07:18:04 +0000 Received: by noisy.programming.kicks-ass.net (Postfix, from userid 1000) id 4A0B830039F; Wed, 22 Oct 2025 10:13:31 +0200 (CEST) Date: Wed, 22 Oct 2025 10:13:31 +0200 From: Peter Zijlstra To: Miguel Ojeda Cc: Gary Guo , Miguel Ojeda , Josh Poimboeuf , Alex Gaynor , Boqun Feng , =?iso-8859-1?Q?Bj=F6rn?= Roy Baron , Benno Lossin , Andreas Hindborg , Alice Ryhl , Trevor Gross , Danilo Krummrich , rust-for-linux@vger.kernel.org, linux-kernel@vger.kernel.org, patches@lists.linux.dev, stable@vger.kernel.org Subject: Re: [PATCH] objtool/rust: add one more `noreturn` Rust function Message-ID: <20251022081331.GJ4067720@noisy.programming.kicks-ass.net> References: <20251020020714.2511718-1-ojeda@kernel.org> <20251020105154.GR3419281@noisy.programming.kicks-ass.net> 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, Oct 21, 2025 at 07:25:11PM +0200, Miguel Ojeda wrote: > On Tue, Oct 21, 2025 at 7:19 PM Peter Zijlstra wrote: > > > > I'll go stick it in tip/objtool/core; but I gotta ask, where are we with > > the toolchain support for noreturn? > > Thanks Peter! > > We discussed it with upstream Rust, and they understood the need, so > we may get something like `--emit=noreturn` or similar, but it is > still open (and not too high in the priority list since we can survive > with this for now and we have other things that we really need them to > get stabilized etc. But if you feel it should be prioritized more, > please let me know). Nah, as long as its not forgotten I suppose it'll show up at some point. I would place including C headers in Rust at a *MUCH* higher priority than this. This bindgen nonsense is a giant pain in the arse. > I have the status under "Export (somehow) a list of all noreturn symbols." at: > > https://github.com/Rust-for-Linux/linux/issues/355 > > In particular, Gary proposed an alternative during those discussions: > > "Gary proposed reading DWARF instead and wrote a quick Rust script > for it via object and gimli, though DWARF would need to be available > or generated on the fly just for that (and we cannot commit a fixed > list since the kernel config may change and we support several Rust > versions and so on): > https://gist.github.com/nbdd0121/449692570622c2f46a29ad9f47c3379a." Right, the problem with DWARF is that you need to have DWARF and debug builds are *SLOW* :/ But perhaps rust compile times are such that that isn't noticable?