From patchwork Fri Aug 5 15:41:54 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Miguel Ojeda X-Patchwork-Id: 12937430 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id C4582C3F6B0 for ; Fri, 5 Aug 2022 15:44:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240968AbiHEPoZ (ORCPT ); Fri, 5 Aug 2022 11:44:25 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47492 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S241217AbiHEPnu (ORCPT ); Fri, 5 Aug 2022 11:43:50 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id F25965C9C5; Fri, 5 Aug 2022 08:43:34 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 78810B82985; Fri, 5 Aug 2022 15:43:33 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 51A84C433B5; Fri, 5 Aug 2022 15:43:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1659714212; bh=A6iE9dGgpooXK06FIGFB3nx2/DurNoGR1fSLObr1bQI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=KZgzX49sIoma/oq+oM86hibh1+DLLsdbrN30c7vQAL8ecBntUNuwLkuRbuYMjBZSc /BlIdONU8gm35OhBTI3P0kmdk41LAeuZL1cF7SPR/orYeDsVzY0x3gHCYCjdM0MO6f HlOoezdJvUi4+QqID+wBClI0Bl94jkXqkNF0BtaqR3DV5Zex/wmszPrDVMEcygY8Np FtipzN2RXDv2MnMbo8maTboPnOHHyi7cuYuMZ4GkBgt3KnboM9WzegZd/8fTA9+BMD 5SJZxm0N6yc2FOJRXWF7lo/CsjB4CpfVSQkUsX8CBqr2C/pmkrA5+CjV5Y76eqIRth nlwt8tipIi8mw== From: Miguel Ojeda To: Linus Torvalds , Greg Kroah-Hartman Cc: rust-for-linux@vger.kernel.org, linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, patches@lists.linux.dev, Jarkko Sakkinen , Miguel Ojeda , Alex Gaynor , Wedson Almeida Filho , Sven Van Asbroeck , Gary Guo , Boqun Feng , =?utf-8?q?Bj=C3=B6rn_Roy_Baron?= Subject: [PATCH v9 09/27] rust: add `compiler_builtins` crate Date: Fri, 5 Aug 2022 17:41:54 +0200 Message-Id: <20220805154231.31257-10-ojeda@kernel.org> In-Reply-To: <20220805154231.31257-1-ojeda@kernel.org> References: <20220805154231.31257-1-ojeda@kernel.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org Rust provides `compiler_builtins` as a port of LLVM's `compiler-rt`. Since we do not need the vast majority of them, we avoid the dependency by providing our own crate. Co-developed-by: Alex Gaynor Signed-off-by: Alex Gaynor Co-developed-by: Wedson Almeida Filho Signed-off-by: Wedson Almeida Filho Co-developed-by: Sven Van Asbroeck Signed-off-by: Sven Van Asbroeck Co-developed-by: Gary Guo Signed-off-by: Gary Guo Signed-off-by: Miguel Ojeda Reviewed-by: Kees Cook --- rust/compiler_builtins.rs | 63 +++++++++++++++++++++++++++++++++++++++ 1 file changed, 63 insertions(+) create mode 100644 rust/compiler_builtins.rs diff --git a/rust/compiler_builtins.rs b/rust/compiler_builtins.rs new file mode 100644 index 000000000000..f8f39a3e6855 --- /dev/null +++ b/rust/compiler_builtins.rs @@ -0,0 +1,63 @@ +// SPDX-License-Identifier: GPL-2.0 + +//! Our own `compiler_builtins`. +//! +//! Rust provides [`compiler_builtins`] as a port of LLVM's [`compiler-rt`]. +//! Since we do not need the vast majority of them, we avoid the dependency +//! by providing this file. +//! +//! At the moment, some builtins are required that should not be. For instance, +//! [`core`] has 128-bit integers functionality which we should not be compiling +//! in. We will work with upstream [`core`] to provide feature flags to disable +//! the parts we do not need. For the moment, we define them to [`panic!`] at +//! runtime for simplicity to catch mistakes, instead of performing surgery +//! on `core.o`. +//! +//! In any case, all these symbols are weakened to ensure we do not override +//! those that may be provided by the rest of the kernel. +//! +//! [`compiler_builtins`]: https://github.com/rust-lang/compiler-builtins +//! [`compiler-rt`]: https://compiler-rt.llvm.org/ + +#![feature(compiler_builtins)] +#![compiler_builtins] +#![no_builtins] +#![no_std] + +macro_rules! define_panicking_intrinsics( + ($reason: tt, { $($ident: ident, )* }) => { + $( + #[doc(hidden)] + #[no_mangle] + pub extern "C" fn $ident() { + panic!($reason); + } + )* + } +); + +define_panicking_intrinsics!("`f32` should not be used", { + __eqsf2, + __gesf2, + __lesf2, + __nesf2, + __unordsf2, +}); + +define_panicking_intrinsics!("`f64` should not be used", { + __unorddf2, +}); + +define_panicking_intrinsics!("`i128` should not be used", { + __ashrti3, + __muloti4, + __multi3, +}); + +define_panicking_intrinsics!("`u128` should not be used", { + __ashlti3, + __lshrti3, + __udivmodti4, + __udivti3, + __umodti3, +});