1/* 2 * CDDL HEADER START 3 * 4 * The contents of this file are subject to the terms of the 5 * Common Development and Distribution License (the "License"). 6 * You may not use this file except in compliance with the License. 7 * 8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 9 * or http://www.opensolaris.org/os/licensing. 10 * See the License for the specific language governing permissions 11 * and limitations under the License. 12 * 13 * When distributing Covered Code, include this CDDL HEADER in each 14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 15 * If applicable, add the following below this CDDL HEADER, with the 16 * fields enclosed by brackets "[]" replaced with your own identifying 17 * information: Portions Copyright [yyyy] [name of copyright owner] 18 * 19 * CDDL HEADER END 20 */ 21 22/* 23 * Copyright 2008 Sun Microsystems, Inc. All rights reserved. 24 * Use is subject to license terms. 25 */ 26 27#pragma ident "%Z%%M% %I% %E% SMI" 28 29 .file "%M%" 30 31#include "SYS.h" 32#include <sys/trap.h> 33 34 ANSI_PRAGMA_WEAK(syscall,function) 35 36/* 37 * See sparc/sys/syscall.s to understand why _syscall6() exists. 38 * On x86, the implementation of the two are the same, the only 39 * difference being that _syscall6 is not an exported symbol. 40 */ 41 ENTRY2(syscall,_syscall6) 42 popl %edx / return address 43 popl %eax / system call number 44 pushl %edx 45#if defined(_SYSC_INSN) 46 .byte 0xf, 0x5 /* syscall */ 47#elif defined(_SEP_INSN) 48 call 8f 498: popl %edx 50 movl %esp, %ecx 51 addl $[9f - 8b], %edx 52 sysenter 539: 54#else 55 int $T_SYSCALLINT 56#endif 57 movl 0(%esp), %edx 58 pushl %edx / restore the return address 59 SYSCERROR 60 ret 61 SET_SIZE(syscall) 62 SET_SIZE(_syscall6) 63 64/* 65 * See sparc/sys/syscall.s to understand why __systemcall6() exists. 66 * On x86, the implementation of the two are the same, the only 67 * difference being that __systemcall6 is not an exported symbol. 68 * 69 * WARNING WARNING WARNING: 70 * The int $T_SYSCALL instruction below is needed by /proc when it scans a 71 * controlled process's text for a syscall instruction. It must be present in 72 * all libc variants because /proc cannot use an optimized syscall instruction 73 * to enter the kernel; optimized syscalls could be disabled by private LDT use. 74 * We must leave at least one int $T_SYSCALLINT in the text for /proc to find 75 * (see the Pscantext() routine). 76 */ 77 ENTRY2(__systemcall,__systemcall6) 78 popl %edx / return address 79 popl %ecx / structure return address 80 popl %eax / system call number 81 pushl %edx 82 int $T_SYSCALLINT 83 jae 1f 84 / error; clear syscall return values in the structure 85 movl $-1, 0(%ecx) / sys_rval1 86 movl $-1, 4(%ecx) / sys_rval2 87 jmp 2f / %eax contains the error number 881: 89 / no error; copy syscall return values to the structure 90 movl %eax, 0(%ecx) / sys_rval1 91 movl %edx, 4(%ecx) / sys_rval2 92 xorl %eax, %eax / no error, set %eax to zero 932: 94 movl 0(%esp), %edx / Restore the stack frame to original size 95 pushl %ecx 96 pushl %edx / restore the return address 97 ret 98 SET_SIZE(__systemcall) 99 SET_SIZE(__systemcall6) 100