From patchwork Thu Aug 3 11:45:19 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Zhangjin Wu X-Patchwork-Id: 13339859 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 C5DD3C001DF for ; Thu, 3 Aug 2023 11:45:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234544AbjHCLpi (ORCPT ); Thu, 3 Aug 2023 07:45:38 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42880 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231809AbjHCLpi (ORCPT ); Thu, 3 Aug 2023 07:45:38 -0400 Received: from bg4.exmail.qq.com (bg4.exmail.qq.com [43.155.65.254]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0A459E53; Thu, 3 Aug 2023 04:45:35 -0700 (PDT) X-QQ-mid: bizesmtp69t1691063125tg1fzsd3 Received: from linux-lab-host.localdomain ( [116.30.131.233]) by bizesmtp.qq.com (ESMTP) with id ; Thu, 03 Aug 2023 19:45:24 +0800 (CST) X-QQ-SSF: 01200000000000E0X000000A0000000 X-QQ-FEAT: ttAhR/+4Rmn6jmIP+0Hmn2EiMIaK/dXPR2h8oFsixpBU5+fEg+Tl16A7g8IDn V+7uny2HFf9kLnF0aRaGC7tzTYcLUah2ZyENwpGeLaAtWUOtH4fumWubfnhqQm61+9sg62I zQfC09UIsC0arXak6/fWmPo6e5uluB4tF9h/afLai0tKr3OgfWVb3D67U2xILjVVePJTiZy 6zu7B0/oS9lzLI0jPw00FQznupRD04FI3JlPN6JUC9ImIYL8exYYplO+kDgyDYMPYcprY52 vAQE4zJKXHup1A79jLuv9HWM+HM4EnirZgRnx1uw0O8Qz6eQm/jTx1ye1jrAu6rgfGu2fvc kWtUYEsm6AoLuwtIhZO21OAHsps3zZaKBiPJUOLAZOaYmFw/tvbLzVaX7s/Wc9x+ofRH61r X-QQ-GoodBg: 0 X-BIZMAIL-ID: 14348619306806666930 From: Zhangjin Wu To: thomas@t-8ch.de, w@1wt.eu Cc: falcon@tinylab.org, arnd@arndb.de, linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org, tanyuan@tinylab.org, =?utf-8?q?Thomas_Wei?= =?utf-8?q?=C3=9Fschuh?= Subject: [PATCH v5 2/8] tools/nolibc: add support for powerpc64 Date: Thu, 3 Aug 2023 19:45:19 +0800 Message-Id: <624b1b87470d7179ac8b6e7be1f6a2dc50004570.1691062722.git.falcon@tinylab.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: References: MIME-Version: 1.0 X-QQ-SENDSIZE: 520 Feedback-ID: bizesmtp:tinylab.org:qybglogicsvrgz:qybglogicsvrgz5a-1 Precedence: bulk List-ID: X-Mailing-List: linux-kselftest@vger.kernel.org This follows the 64-bit PowerPC ABI [1], refers to the slides: "A new ABI for little-endian PowerPC64 Design & Implementation" [2] and the musl code in arch/powerpc64/crt_arch.h. First, stdu and clrrdi are used instead of stwu and clrrwi for powerpc64. Second, the stack frame size is increased to 32 bytes for powerpc64, 32 bytes is the minimal stack frame size supported described in [2]. Besides, the TOC pointer (GOT pointer) must be saved to r2. This works on both little endian and big endian 64-bit PowerPC. [1]: https://refspecs.linuxfoundation.org/ELF/ppc64/PPC-elf64abi.pdf [2]: https://www.llvm.org/devmtg/2014-04/PDFs/Talks/Euro-LLVM-2014-Weigand.pdf Reviewed-by: Thomas Weißschuh Signed-off-by: Zhangjin Wu --- tools/include/nolibc/arch-powerpc.h | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) diff --git a/tools/include/nolibc/arch-powerpc.h b/tools/include/nolibc/arch-powerpc.h index 8332c9d3e5d6..76c3784f9dc7 100644 --- a/tools/include/nolibc/arch-powerpc.h +++ b/tools/include/nolibc/arch-powerpc.h @@ -172,6 +172,7 @@ _ret; \ }) +#ifndef __powerpc64__ /* FIXME: For 32-bit PowerPC, with newer gcc compilers (e.g. gcc 13.1.0), * "omit-frame-pointer" fails with __attribute__((no_stack_protector)) but * works with __attribute__((__optimize__("-fno-stack-protector"))) @@ -180,10 +181,24 @@ #undef __no_stack_protector #define __no_stack_protector __attribute__((__optimize__("-fno-stack-protector"))) #endif +#endif /* !__powerpc64__ */ /* startup code */ void __attribute__((weak, noreturn, optimize("Os", "omit-frame-pointer"))) __no_stack_protector _start(void) { +#ifdef __powerpc64__ + /* On 64-bit PowerPC, save TOC/GOT pointer to r2 */ + extern char TOC __asm__ (".TOC."); + register volatile long r2 __asm__ ("r2") = (void *)&TOC - (void *)_start; + + __asm__ volatile ( + "mr 3, 1\n" /* save stack pointer to r3, as arg1 of _start_c */ + "clrrdi 1, 1, 4\n" /* align the stack to 16 bytes */ + "li 0, 0\n" /* zero the frame pointer */ + "stdu 1, -32(1)\n" /* the initial stack frame */ + "bl _start_c\n" /* transfer to c runtime */ + ); +#else __asm__ volatile ( "mr 3, 1\n" /* save stack pointer to r3, as arg1 of _start_c */ "clrrwi 1, 1, 4\n" /* align the stack to 16 bytes */ @@ -191,6 +206,7 @@ void __attribute__((weak, noreturn, optimize("Os", "omit-frame-pointer"))) __no_ "stwu 1, -16(1)\n" /* the initial stack frame */ "bl _start_c\n" /* transfer to c runtime */ ); +#endif __builtin_unreachable(); }