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, Version 1.0 only 6 * (the "License"). You may not use this file except in compliance 7 * with the License. 8 * 9 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 10 * or http://www.opensolaris.org/os/licensing. 11 * See the License for the specific language governing permissions 12 * and limitations under the License. 13 * 14 * When distributing Covered Code, include this CDDL HEADER in each 15 * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 16 * If applicable, add the following below this CDDL HEADER, with the 17 * fields enclosed by brackets "[]" replaced with your own identifying 18 * information: Portions Copyright [yyyy] [name of copyright owner] 19 * 20 * CDDL HEADER END 21 */ 22/* 23 * Copyright 2005 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/asm_linkage.h> 32#include <sys/trap.h> 33 34 ANSI_PRAGMA_WEAK(syscall,function) 35 36#include "SYS.h" 37 38#undef _syscall /* override "synonyms.h" */ 39#undef __systemcall 40 41/* 42 * See sparc/sys/syscall.s to understand why __syscall6() exists. 43 * On x86, the implementation of the two are the same, the only 44 * difference being that __syscall6 is not an exported symbol. 45 */ 46 ENTRY2(_syscall,_syscall6) 47 popl %edx / return address 48 popl %eax / system call number 49 pushl %edx 50#if defined(_SYSC_INSN) 51 .byte 0xf, 0x5 /* syscall */ 52#elif defined(_SEP_INSN) 53 call 8f 548: popl %edx 55 movl %esp, %ecx 56 addl $[9f - 8b], %edx 57 sysenter 589: 59#else 60 int $T_SYSCALLINT 61#endif 62 movl 0(%esp), %edx 63 pushl %edx / restore the return address 64 SYSCERROR 65 ret 66 SET_SIZE(_syscall) 67 SET_SIZE(_syscall6) 68 69/* 70 * See sparc/sys/syscall.s to understand why __systemcall6() exists. 71 * On x86, the implementation of the two are the same, the only 72 * difference being that __systemcall6 is not an exported symbol. 73 * 74 * WARNING WARNING WARNING: 75 * The int $T_SYSCALL instruction below is needed by /proc when it scans a 76 * controlled process's text for a syscall instruction. It must be present in 77 * all libc variants because /proc cannot use an optimized syscall instruction 78 * to enter the kernel; optimized syscalls could be disabled by private LDT use. 79 * We must leave at least one int $T_SYSCALLINT in the text for /proc to find 80 * (see the Pscantext() routine). 81 */ 82 ENTRY2(__systemcall,__systemcall6) 83 popl %edx / return address 84 popl %ecx / structure return address 85 popl %eax / system call number 86 pushl %edx 87 int $T_SYSCALLINT 88 jae 1f 89 / error; clear syscall return values in the structure 90 movl $-1, 0(%ecx) / sys_rval1 91 movl $-1, 4(%ecx) / sys_rval2 92 jmp 2f / %eax contains the error number 931: 94 / no error; copy syscall return values to the structure 95 movl %eax, 0(%ecx) / sys_rval1 96 movl %edx, 4(%ecx) / sys_rval2 97 xorl %eax, %eax / no error, set %eax to zero 982: 99 movl 0(%esp), %edx / Restore the stack frame to original size 100 pushl %ecx 101 pushl %edx / restore the return address 102 ret 103 SET_SIZE(__systemcall) 104 SET_SIZE(__systemcall6) 105