From patchwork Sat Jul 15 18:28:55 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Zhangjin Wu X-Patchwork-Id: 13314596 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 819CBC0015E for ; Sat, 15 Jul 2023 18:29:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229657AbjGOS3I (ORCPT ); Sat, 15 Jul 2023 14:29:08 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44538 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229881AbjGOS3H (ORCPT ); Sat, 15 Jul 2023 14:29:07 -0400 Received: from bg4.exmail.qq.com (bg4.exmail.qq.com [43.155.65.254]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id F1F641B6; Sat, 15 Jul 2023 11:29:05 -0700 (PDT) X-QQ-mid: bizesmtp86t1689445737tf40gpis Received: from linux-lab-host.localdomain ( [119.123.131.162]) by bizesmtp.qq.com (ESMTP) with id ; Sun, 16 Jul 2023 02:28:55 +0800 (CST) X-QQ-SSF: 01200000002000D0W000B00A0000000 X-QQ-FEAT: XBN7tc9DADIQjIsqRzL4vnYwH3N5Sgo1e7zNB/4n2AgqX677h/fDkeZyT9mYf p0IixsvqeeAt2UvN1ybU7s1krWgel5YrPsv0SO+G8CtUR+CxOxQBYSTlEokUqIe5X/4+rSf hIN7zBwwCEH+2PIPM0F7507O5d9Ii5cJNCuD9iFA0WdguPU42KgAe7lOawK0TSSQtRdk/E2 +6KU6MM+DvJ38yUlS33v31iJVG4KE4XkaewvjxfpT3uvN0XM586BYLh2aau7FRIToHhSJft 6Ru92wNpGVe5kMevRWzeslGC5QBOTxRgLZ7/uLtAcsYPIXQ2vrVpffuK70dw3wFIVnJvxj5 DXuSoh11+1feWBMIGr3kFanD01bvmqYSGOcrZGhL8gEMBIaK8NzPHKbigIOsw== X-QQ-GoodBg: 0 X-BIZMAIL-ID: 16748570457034606427 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 11/18] tools/nolibc: mips: shrink _start with _start_c Date: Sun, 16 Jul 2023 02:28:55 +0800 Message-Id: <107f96c69d54a39e1a161aca25d36289e343c1a1.1689444638.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 move most of the _start operations to _start_c(), include the stackprotector initialization. Also clean up the instructions in delayed slots. Signed-off-by: Zhangjin Wu --- tools/include/nolibc/arch-mips.h | 46 ++++++-------------------------- 1 file changed, 8 insertions(+), 38 deletions(-) diff --git a/tools/include/nolibc/arch-mips.h b/tools/include/nolibc/arch-mips.h index 7242fc9de04f..4ab6fa54beee 100644 --- a/tools/include/nolibc/arch-mips.h +++ b/tools/include/nolibc/arch-mips.h @@ -8,6 +8,7 @@ #define _NOLIBC_ARCH_MIPS_H #include "compiler.h" +#include "crt.h" /* Syscalls for MIPS ABI O32 : * - WARNING! there's always a delayed slot! @@ -173,50 +174,19 @@ _arg4 ? -_num : _num; \ }) -char **environ __attribute__((weak)); -const unsigned long *_auxv __attribute__((weak)); - /* startup code, note that it's called __start on MIPS */ void __attribute__((weak, noreturn, optimize("Os", "omit-frame-pointer"))) __no_stack_protector __start(void) { __asm__ volatile ( - /*".set nomips16\n"*/ ".set push\n" - ".set noreorder\n" + ".set noreorder\n" ".option pic0\n" -#ifdef _NOLIBC_STACKPROTECTOR - "jal __stack_chk_init\n" /* initialize stack protector */ - "nop\n" /* delayed slot */ -#endif - /*".ent __start\n"*/ - /*"__start:\n"*/ - "lw $a0,($sp)\n" /* argc was in the stack */ - "addiu $a1, $sp, 4\n" /* argv = sp + 4 */ - "sll $a2, $a0, 2\n" /* a2 = argc * 4 */ - "add $a2, $a2, $a1\n" /* envp = argv + 4*argc ... */ - "addiu $a2, $a2, 4\n" /* ... + 4 */ - "lui $a3, %hi(environ)\n" /* load environ into a3 (hi) */ - "addiu $a3, %lo(environ)\n" /* load environ into a3 (lo) */ - "sw $a2,($a3)\n" /* store envp(a2) into environ */ - - "move $t0, $a2\n" /* iterate t0 over envp, look for NULL */ - "0:" /* do { */ - "lw $a3, ($t0)\n" /* a3=*(t0); */ - "bne $a3, $0, 0b\n" /* } while (a3); */ - "addiu $t0, $t0, 4\n" /* delayed slot: t0+=4; */ - "lui $a3, %hi(_auxv)\n" /* load _auxv into a3 (hi) */ - "addiu $a3, %lo(_auxv)\n" /* load _auxv into a3 (lo) */ - "sw $t0, ($a3)\n" /* store t0 into _auxv */ - - "li $t0, -8\n" - "and $sp, $sp, $t0\n" /* sp must be 8-byte aligned */ - "addiu $sp,$sp,-16\n" /* the callee expects to save a0..a3 there! */ - "jal main\n" /* main() returns the status code, we'll exit with it. */ - "nop\n" /* delayed slot */ - "move $a0, $v0\n" /* retrieve 32-bit exit code from v0 */ - "li $v0, 4001\n" /* NR_exit == 4001 */ - "syscall\n" - /*".end __start\n"*/ + "move $a0, $sp\n" /* save stack pointer to $a0, as arg1 of _start_c */ + "li $t0, -8\n" + "and $sp, $sp, $t0\n" /* $sp must be 8-byte aligned */ + "addiu $sp, $sp, -16\n" /* the callee expects to save a0..a3 there */ + "jal _start_c\n" /* transfer to c runtime */ + " nop\n" /* delayed slot */ ".set pop\n" ); __builtin_unreachable();