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 5B690442364; Mon, 17 Aug 2026 18:12:19 +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=1786990340; cv=none; b=SThf3VVDvXSI2hznIxfY16/pZ2X7w0IrtdXK5msgUjJUELE4QXD3bMEEhiv5t8ac5Np3U1hrWvFFpE/C1ATIPjzuof8LlaVezhe1xRmvyB+8Lhp9+PY9tHqwhmCsoefO828KbTY09EV5zn9KF5aj/AsLPQuXGaHkAWyKbFmOt6M= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786990340; c=relaxed/simple; bh=jw3E4GvzjLsrAQxKeX1+l5jtVDZfGjR3B+gVNNIXclk=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=aj7PNyMAJlGgYKOn/1d13epmrdRW5D4fc9wZvXXnYT1oWqkQMqaNNwhSgXblXNzmyZJcVfPK2qoeR9BzvWb7jk2ARNmJatpMKE07lP6GB6Z/Z6cHeOdGJ+8Zldib112rrXszud5AOQoLTsEfFnXPXiZcyJECQ3q9t5qcEIFJr/k= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=a+sT4F+G; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="a+sT4F+G" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 641301F000E9; Mon, 17 Aug 2026 18:12:15 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1786990339; bh=J7lbDjvO1YdRXrmvFso2O876QXWoj5AWCIxP88NH1X8=; h=Date:From:To:Cc:Subject:References:In-Reply-To; b=a+sT4F+GJYaSNjb50jcFC4YqIT+JQNphWc1wtIWhPDDL8+aScAYNcUWLXRaFl6P49 NtdTTYMHKNNxcvj/AalOEcas0E6ILPKaZygqZYxOFIp2T0qOt8etzOJ2XHonWeXj3L PyAtVXUudtQ7kiSL8+Yk/NYh4jjsg9dVAQoKE+rHTLzMiI2Z0SqOXOh0H0vV4xGa/d QQZdLMvixixZTvzWpenYeIe0amY5cegNEk0WqaFPyvFJIfUl9datlTPtK2zqbVb7IB 5btLO2c9yHBE03Id1lNmKsILdfKnrTHmj/2b29ltVn5/eRYQAeZvpndTxMJg9vpqvh mM5UvcDZkb4Mw== Date: Mon, 17 Aug 2026 11:12:12 -0700 From: Nathan Chancellor To: Miguel Ojeda Cc: Nicolas Schier , Boqun Feng , Gary Guo , Matthew Maurer , Alice Ryhl , Josh Poimboeuf , Peter Zijlstra , linux-kbuild@vger.kernel.org, =?iso-8859-1?Q?Bj=F6rn?= Roy Baron , Benno Lossin , Andreas Hindborg , Trevor Gross , Danilo Krummrich , Daniel Almeida , Tamir Duberstein , Alexandre Courbot , Onur =?iso-8859-1?Q?=D6zkan?= , rust-for-linux@vger.kernel.org, stable@vger.kernel.org Subject: Re: [PATCH 2/2] kbuild: rust: keep Rust objects out of Clang LTO with inline helpers Message-ID: <20260817181212.GA1249844@ax162> References: <20260816133233.197500-1-ojeda@kernel.org> <20260816133233.197500-2-ojeda@kernel.org> Precedence: bulk X-Mailing-List: linux-kbuild@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: <20260816133233.197500-2-ojeda@kernel.org> On Sun, Aug 16, 2026 at 03:32:33PM +0200, Miguel Ojeda wrote: > Another possible alternative that Gary suggested is to turn the flags on > globally for C, whether only when inline helpers are enabled or in all > cases, but it may be intended that in C we expect not to generate the > `unreachable`s. I am not sure we can use '-mllvm -trap-unreachable' for C code, as that would mess with manually inserted calls to __builtin_unreachable(). It has come up before: https://lore.kernel.org/CAHk-=wgPCbZv0JgqoNWMOO+p=N772YW16xYk_pmb1GU7aeuPFA@mail.gmail.com/ It is possible the '-no-trap-after-noreturn' avoids that particular issue but I still think the "compiler inserted" vs. "user inserted" distinction that Linus comments on is likely still potentially relevant. -- Cheers, Nathan