From patchwork Tue May 13 22:22:21 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Roland McGrath X-Patchwork-Id: 896 Return-Path: X-Original-To: siddhesh@wilcox.dreamhost.com Delivered-To: siddhesh@wilcox.dreamhost.com Received: from homiemail-mx20.g.dreamhost.com (mx2.sub5.homie.mail.dreamhost.com [208.113.200.128]) by wilcox.dreamhost.com (Postfix) with ESMTP id 5ECFA3600BE for ; Tue, 13 May 2014 15:22:28 -0700 (PDT) Received: by homiemail-mx20.g.dreamhost.com (Postfix, from userid 14307373) id 150B041A3D60C; Tue, 13 May 2014 15:22:28 -0700 (PDT) X-Original-To: glibc@patchwork.siddhesh.in Delivered-To: x14307373@homiemail-mx20.g.dreamhost.com Received: from sourceware.org (server1.sourceware.org [209.132.180.131]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by homiemail-mx20.g.dreamhost.com (Postfix) with ESMTPS id E3CEB41A3D604 for ; Tue, 13 May 2014 15:22:27 -0700 (PDT) DomainKey-Signature: a=rsa-sha1; c=nofws; d=sourceware.org; h=list-id :list-unsubscribe:list-subscribe:list-archive:list-post :list-help:sender:mime-version:content-type :content-transfer-encoding:from:to:subject:in-reply-to :references:message-id:date; q=dns; s=default; b=F7Y7xRpbhgOYBJ8 6DgRXM+ScBSoX5WdNdAk6NhEjqpWaNpDWNHr8LJEugmrV5RGE8pVAdNfEj9h5tK/ +XBaXmTUt2ADCxySnN9eIE9eu7iQ8mLlOIdiTVgHraF4BFYfOW+lJjFC7GSTAB94 BykkujvU9Fx8dHyBnZD218g/jF/o= DKIM-Signature: v=1; a=rsa-sha1; c=relaxed; d=sourceware.org; h=list-id :list-unsubscribe:list-subscribe:list-archive:list-post :list-help:sender:mime-version:content-type :content-transfer-encoding:from:to:subject:in-reply-to :references:message-id:date; s=default; bh=kyNbjmzNGlv5TW4JwktKT 7Zor+E=; b=voPzGXbSqJn2NN+hrxNM2AePKKi0hkHyZrRIkWZ0M/zGetNA2rp+5 x1Qc9li55xB4gx8cZb/W0LkKIdt4p7+BWiISy36k3SNDi21GL/kTPyzjn86EiFI/ m6JCmRBkIrMwp8tbdcUkYQAM3g6nvdlzBwE0MNFmFo/AH2O9PigXD0= Received: (qmail 31586 invoked by alias); 13 May 2014 22:22:25 -0000 Mailing-List: contact libc-alpha-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Unsubscribe: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: libc-alpha-owner@sourceware.org Delivered-To: mailing list libc-alpha@sourceware.org Received: (qmail 31577 invoked by uid 89); 13 May 2014 22:22:25 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-2.3 required=5.0 tests=AWL, BAYES_00 autolearn=ham version=3.3.2 X-HELO: topped-with-meat.com MIME-Version: 1.0 From: Roland McGrath To: "GNU C. Library" Subject: Re: [PATCH 2/2 roland/nptl] x86: Consolidate NPTL/non versions of vfork In-Reply-To: Roland McGrath's message of Tuesday, 13 May 2014 15:19:39 -0700 <20140513221939.A63F52C39B4@topped-with-meat.com> References: <20140513221939.A63F52C39B4@topped-with-meat.com> Message-Id: <20140513222221.CAF4E2C39DB@topped-with-meat.com> Date: Tue, 13 May 2014 15:22:21 -0700 (PDT) X-CMAE-Score: 0 X-CMAE-Analysis: v=2.1 cv=HrjlRSjS c=1 sm=1 tr=0 a=WkljmVdYkabdwxfqvArNOQ==:117 a=14OXPxybAAAA:8 a=N8AxCe0s3u8A:10 a=Z6MIti7PxpgA:10 a=kj9zAlcOel0A:10 a=hOe2yjtxAAAA:8 a=mDV3o1hIAAAA:8 a=BoFio5xOTkJ6oDeo6vMA:9 a=E5_IQ1Foshhm2YE6:21 a=oLF78gm7z4LAvIQ_:21 a=CjuIK1q_8ugA:10 a=ii61gXl28gQA:10 X-DH-Original-To: glibc@patchwork.siddhesh.in This requires the 1/1 (ARM) patch be in place first, for the libpthread vfork compatibility code that is machine-independent. Tested x86_64-linux-gnu and i686-linux-gnu. If nobody objects, I'll commit this after Joseph approves the ARM change. Thanks, Roland * sysdeps/unix/sysv/linux/i386/vfork.S: Include . (__vfork): Incorporate save/restore of PID from nptl/vfork.S here. (__libc_vfork): New strong alias. * nptl/sysdeps/unix/sysv/linux/i386/vfork.S: File removed. * nptl/sysdeps/unix/sysv/linux/i386/pt-vfork.S: File removed. * sysdeps/unix/sysv/linux/x86_64/vfork.S: Include . (__vfork): Incorporate save/restore of PID from nptl/vfork.S here. (__libc_vfork): New strong alias. * nptl/sysdeps/unix/sysv/linux/x86_64/vfork.S: File removed. * nptl/sysdeps/unix/sysv/linux/x86_64/pt-vfork.S: File removed. --- a/nptl/sysdeps/unix/sysv/linux/i386/pt-vfork.S +++ /dev/null @@ -1,66 +0,0 @@ -/* Copyright (C) 1999-2014 Free Software Foundation, Inc. - This file is part of the GNU C Library. - Contributed by Andreas Schwab . - - The GNU C Library is free software; you can redistribute it and/or - modify it under the terms of the GNU Lesser General Public - License as published by the Free Software Foundation; either - version 2.1 of the License, or (at your option) any later version. - - The GNU C Library is distributed in the hope that it will be useful, - but WITHOUT ANY WARRANTY; without even the implied warranty of - MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU - Lesser General Public License for more details. - - You should have received a copy of the GNU Lesser General Public - License along with the GNU C Library; if not, see - . */ - -#include -#define _ERRNO_H 1 -#include -#include -#include - -/* Save the PID value. */ -#define SAVE_PID \ - movl %gs:PID, %edx; \ - movl %edx, %eax; \ - negl %eax; \ - movl %eax, %gs:PID - -/* Restore the old PID value in the parent. */ -#define RESTORE_PID \ - testl %eax, %eax; \ - je 1f; \ - movl %edx, %gs:PID; \ -1: - -/* Clone the calling process, but without copying the whole address space. - The calling process is suspended until the new process exits or is - replaced by a call to `execve'. Return -1 for errors, 0 to the new process, - and the process ID of the new process to the old process. */ - -ENTRY (__vfork) - /* Pop the return PC value into ECX. */ - popl %ecx - - SAVE_PID - - /* Stuff the syscall number in EAX and enter into the kernel. */ - movl $SYS_ify (vfork), %eax - int $0x80 - - RESTORE_PID - - /* Jump to the return PC. Don't jump directly since this - disturbs the branch target cache. Instead push the return - address back on the stack. */ - pushl %ecx - - cmpl $-4095, %eax - jae SYSCALL_ERROR_LABEL /* Branch forward if it failed. */ - ret -PSEUDO_END (__vfork) - -weak_alias (__vfork, vfork) --- a/nptl/sysdeps/unix/sysv/linux/i386/vfork.S +++ /dev/null @@ -1,44 +0,0 @@ -/* Copyright (C) 1999-2014 Free Software Foundation, Inc. - This file is part of the GNU C Library. - - The GNU C Library is free software; you can redistribute it and/or - modify it under the terms of the GNU Lesser General Public - License as published by the Free Software Foundation; either - version 2.1 of the License, or (at your option) any later version. - - The GNU C Library is distributed in the hope that it will be useful, - but WITHOUT ANY WARRANTY; without even the implied warranty of - MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU - Lesser General Public License for more details. - - You should have received a copy of the GNU Lesser General Public - License along with the GNU C Library; if not, see - . */ - -/* We want an #include_next, but we are the main source file. - So, #include ourselves and in that incarnation we can use #include_next. */ -#ifndef INCLUDED_SELF -# define INCLUDED_SELF -# include -#else - -# include - -/* Save the PID value. */ -# define SAVE_PID \ - movl %gs:PID, %edx; \ - movl %edx, %eax; \ - negl %eax; \ - jne 1f; \ - movl $0x80000000, %eax; \ -1: movl %eax, %gs:PID - -/* Restore the old PID value in the parent. */ -# define RESTORE_PID \ - testl %eax, %eax; \ - je 1f; \ - movl %edx, %gs:PID; \ -1: - -# include_next -#endif --- a/nptl/sysdeps/unix/sysv/linux/x86_64/pt-vfork.S +++ /dev/null @@ -1,32 +0,0 @@ -/* Copyright (C) 2004-2014 Free Software Foundation, Inc. - This file is part of the GNU C Library. - - The GNU C Library is free software; you can redistribute it and/or - modify it under the terms of the GNU Lesser General Public - License as published by the Free Software Foundation; either - version 2.1 of the License, or (at your option) any later version. - - The GNU C Library is distributed in the hope that it will be useful, - but WITHOUT ANY WARRANTY; without even the implied warranty of - MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU - Lesser General Public License for more details. - - You should have received a copy of the GNU Lesser General Public - License along with the GNU C Library; if not, see - . */ - -#include - -#define SAVE_PID \ - movl %fs:PID, %esi; \ - movl %esi, %edx; \ - negl %edx; \ - movl %edx, %fs:PID - -#define RESTORE_PID \ - testq %rax, %rax; \ - je 1f; \ - movl %esi, %fs:PID; \ -1: - -#include <../../../../../../sysdeps/unix/sysv/linux/x86_64/vfork.S> --- a/nptl/sysdeps/unix/sysv/linux/x86_64/vfork.S +++ /dev/null @@ -1,42 +0,0 @@ -/* Copyright (C) 2004-2014 Free Software Foundation, Inc. - This file is part of the GNU C Library. - - The GNU C Library is free software; you can redistribute it and/or - modify it under the terms of the GNU Lesser General Public - License as published by the Free Software Foundation; either - version 2.1 of the License, or (at your option) any later version. - - The GNU C Library is distributed in the hope that it will be useful, - but WITHOUT ANY WARRANTY; without even the implied warranty of - MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU - Lesser General Public License for more details. - - You should have received a copy of the GNU Lesser General Public - License along with the GNU C Library; if not, see - . */ - -/* We want an #include_next, but we are the main source file. - So, #include ourselves and in that incarnation we can use #include_next. */ -#ifndef INCLUDED_SELF -# define INCLUDED_SELF -# include -#else - -# include - -# define SAVE_PID \ - movl %fs:PID, %esi; \ - movl $0x80000000, %ecx; \ - movl %esi, %edx; \ - negl %edx; \ - cmove %ecx, %edx; \ - movl %edx, %fs:PID - -# define RESTORE_PID \ - testq %rax, %rax; \ - je 1f; \ - movl %esi, %fs:PID; \ -1: - -# include_next -#endif --- a/sysdeps/unix/sysv/linux/i386/vfork.S +++ b/sysdeps/unix/sysv/linux/i386/vfork.S @@ -20,6 +20,8 @@ #define _ERRNO_H 1 #include #include +#include + /* Clone the calling process, but without copying the whole address space. The calling process is suspended until the new process exits or is @@ -33,9 +35,16 @@ ENTRY (__vfork) cfi_adjust_cfa_offset (-4) cfi_register (%eip, %ecx) -#ifdef SAVE_PID - SAVE_PID -#endif + /* Save the TCB-cached PID away in %edx, and then negate the TCB + field. But if it's zero, set it to 0x80000000 instead. See + raise.c for the logic that relies on this value. */ + movl %gs:PID, %edx + movl %edx, %eax + negl %eax + jne 1f + movl $0x80000000, %eax +1: movl %eax, %gs:PID + /* Stuff the syscall number in EAX and enter into the kernel. */ movl $SYS_ify (vfork), %eax @@ -47,9 +56,13 @@ ENTRY (__vfork) pushl %ecx cfi_adjust_cfa_offset (4) -#ifdef RESTORE_PID - RESTORE_PID -#endif + /* Restore the original value of the TCB cache of the PID, if we're + the parent. But in the child (syscall return value equals zero), + leave things as they are. */ + testl %eax, %eax + je 1f + movl %edx, %gs:PID +1: cmpl $-4095, %eax /* Branch forward if it failed. */ @@ -61,3 +74,4 @@ PSEUDO_END (__vfork) libc_hidden_def (__vfork) weak_alias (__vfork, vfork) +strong_alias (__vfork, __libc_vfork) --- a/sysdeps/unix/sysv/linux/x86_64/vfork.S +++ b/sysdeps/unix/sysv/linux/x86_64/vfork.S @@ -18,6 +18,8 @@ #include #define _ERRNO_H 1 #include +#include + /* Clone the calling process, but without copying the whole address space. The calling process is suspended until the new process exits or is @@ -32,9 +34,15 @@ ENTRY (__vfork) cfi_adjust_cfa_offset(-8) cfi_register(%rip, %rdi) -#ifdef SAVE_PID - SAVE_PID -#endif + /* Save the TCB-cached PID away in %esi, and then negate the TCB + field. But if it's zero, set it to 0x80000000 instead. See + raise.c for the logic that relies on this value. */ + movl %fs:PID, %esi + movl $0x80000000, %ecx + movl %esi, %edx + negl %edx + cmove %ecx, %edx + movl %edx, %fs:PID /* Stuff the syscall number in RAX and enter into the kernel. */ movl $SYS_ify (vfork), %eax @@ -44,9 +52,13 @@ ENTRY (__vfork) pushq %rdi cfi_adjust_cfa_offset(8) -#ifdef RESTORE_PID - RESTORE_PID -#endif + /* Restore the original value of the TCB cache of the PID, if we're + the parent. But in the child (syscall return value equals zero), + leave things as they are. */ + testq %rax, %rax + je 1f + movl %esi, %fs:PID +1: cmpl $-4095, %eax jae SYSCALL_ERROR_LABEL /* Branch forward if it failed. */ @@ -58,3 +70,4 @@ PSEUDO_END (__vfork) libc_hidden_def (__vfork) weak_alias (__vfork, vfork) +strong_alias (__vfork, __libc_vfork)