From patchwork Sat Jul 15 18:26:42 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Zhangjin Wu X-Patchwork-Id: 13314594 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 17A5BC0015E for ; Sat, 15 Jul 2023 18:26:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229628AbjGOS0z (ORCPT ); Sat, 15 Jul 2023 14:26:55 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43658 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229632AbjGOS0y (ORCPT ); Sat, 15 Jul 2023 14:26:54 -0400 Received: from bg4.exmail.qq.com (bg4.exmail.qq.com [43.154.54.12]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8D77A1B6; Sat, 15 Jul 2023 11:26:52 -0700 (PDT) X-QQ-mid: bizesmtp82t1689445603tsgi0gsl Received: from linux-lab-host.localdomain ( [119.123.131.162]) by bizesmtp.qq.com (ESMTP) with id ; Sun, 16 Jul 2023 02:26:42 +0800 (CST) X-QQ-SSF: 01200000002000D0W000B00A0000000 X-QQ-FEAT: qOAV9bwDT/kSqlse5e4lug4VHat/aabuEX5Xe9QzvVHXgMbvO7tddyAjjH/68 xTd05Ua+5kRzIU5qS1j5MKyAqWhZyjT91W5Oi6Bmglyi5TVZajNBXqoYE/oDVBrueWFhwz7 WMmg8VfRnNbuOfHL5euQK/qBWuOCcOKUEizedUGzSr795imKLa69WK2Wlx6gLhqllep1ALC iOlC5LPc8IjWcCrdAvX0M3Jcryn00W04sAN04OWwN2Bv0DC/aUns7qmZvcyjbgJJQ5SFLko 9DCcTYm/Fj7VatdK1Aqi8fnm3SPUhp/Ze4x8Hq2vJXBF8eUrFVql7n5ja1/V/f62aPvSIhr 7ZpmSgWV0UxpglS68tAFjWNsHsEpkFSdxtEpx6yHUG0tkLZ5RJ7KYCYUtzMNg== X-QQ-GoodBg: 0 X-BIZMAIL-ID: 1089036118975101126 From: Zhangjin Wu To: w@1wt.eu Cc: arnd@arndb.de, falcon@tinylab.org, linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org, thomas@t-8ch.de Subject: [PATCH v4 09/18] tools/nolibc: i386: shrink _start with _start_c Date: Sun, 16 Jul 2023 02:26:42 +0800 Message-Id: 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 move most of the _start operations to _start_c(), include the stackprotector initialization. Signed-off-by: Zhangjin Wu --- tools/include/nolibc/arch-i386.h | 34 +++++++------------------------- 1 file changed, 7 insertions(+), 27 deletions(-) diff --git a/tools/include/nolibc/arch-i386.h b/tools/include/nolibc/arch-i386.h index fe0b73f032c3..64415b9fac77 100644 --- a/tools/include/nolibc/arch-i386.h +++ b/tools/include/nolibc/arch-i386.h @@ -8,6 +8,7 @@ #define _NOLIBC_ARCH_I386_H #include "compiler.h" +#include "crt.h" /* Syscalls for i386 : * - mostly similar to x86_64 @@ -154,9 +155,6 @@ _eax; \ }) -char **environ __attribute__((weak)); -const unsigned long *_auxv __attribute__((weak)); - /* startup code */ /* * i386 System V ABI mandates: @@ -167,30 +165,12 @@ const unsigned long *_auxv __attribute__((weak)); void __attribute__((weak, noreturn, optimize("Os", "omit-frame-pointer"))) __no_stack_protector _start(void) { __asm__ volatile ( -#ifdef _NOLIBC_STACKPROTECTOR - "call __stack_chk_init\n" /* initialize stack protector */ -#endif - "pop %eax\n" /* argc (first arg, %eax) */ - "mov %esp, %ebx\n" /* argv[] (second arg, %ebx) */ - "lea 4(%ebx,%eax,4),%ecx\n" /* then a NULL then envp (third arg, %ecx) */ - "mov %ecx, environ\n" /* save environ */ - "xor %ebp, %ebp\n" /* zero the stack frame */ - "mov %ecx, %edx\n" /* search for auxv (follows NULL after last env) */ - "0:\n" - "add $4, %edx\n" /* search for auxv using edx, it follows the */ - "cmp -4(%edx), %ebp\n" /* ... NULL after last env (ebp is zero here) */ - "jnz 0b\n" - "mov %edx, _auxv\n" /* save it into _auxv */ - "and $-16, %esp\n" /* x86 ABI : esp must be 16-byte aligned before */ - "sub $4, %esp\n" /* the call instruction (args are aligned) */ - "push %ecx\n" /* push all registers on the stack so that we */ - "push %ebx\n" /* support both regparm and plain stack modes */ - "push %eax\n" - "call main\n" /* main() returns the status code in %eax */ - "mov %eax, %ebx\n" /* retrieve exit code (32-bit int) */ - "movl $1, %eax\n" /* NR_exit == 1 */ - "int $0x80\n" /* exit now */ - "hlt\n" /* ensure it does not */ + "xor %ebp, %ebp\n" /* zero the stack frame */ + "mov %esp, %eax\n" /* save stack pointer to %eax, as arg1 of _start_c */ + "and $-16, %esp\n" /* last pushed argument must be 16-byte aligned */ + "push %eax\n" /* push arg1 on stack to support plain stack modes too */ + "call _start_c\n" /* transfer to c runtime */ + "hlt\n" /* ensure it does not return */ ); __builtin_unreachable(); }