1/* $NetBSD: ptrace.S,v 1.6 2014/11/24 15:33:18 christos Exp $ */ 2 3/*- 4 * Copyright (c) 1990 The Regents of the University of California. 5 * All rights reserved. 6 * 7 * This code is derived from software contributed to Berkeley by 8 * William Jolitz. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 3. Neither the name of the University nor the names of its contributors 19 * may be used to endorse or promote products derived from this software 20 * without specific prior written permission. 21 * 22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32 * SUCH DAMAGE. 33 * 34 * from: @(#)ptrace.s 5.1 (Berkeley) 4/23/90 35 */ 36 37#include <machine/asm.h> 38#if defined(SYSLIBC_SCCS) && !defined(lint) 39 RCSID("$NetBSD: ptrace.S,v 1.6 2014/11/24 15:33:18 christos Exp $") 40#endif /* SYSLIBC_SCCS and not lint */ 41 42#include "SYS.h" 43 44 .globl _C_LABEL(__errno) 45 46ENTRY(ptrace) 47 /* 48 * The following code calls __errno() to set it to 0 before 49 * calling ptrace(2). The libc version of __errno() does not use 50 * any registers, but the libpthread version clobbers %rcx 51 * before we get a chance to store it in %r10. So we save it 52 * in %r10 and restore it. 53 */ 54 movq %rcx, %r10 55#ifdef __PIC__ 56 call PIC_PLT(_C_LABEL(__errno)) 57#else 58 call _C_LABEL(__errno) 59#endif /* __PIC__ */ 60 movl $0,(%rax) 61 movq %r10, %rcx 62 SYSTRAP(ptrace) 63 jc err 64 ret 65err: 66 jmp CERROR 67END(ptrace) 68