ia32_syscall.c revision 200444
1/*- 2 * Copyright (C) 1994, David Greenman 3 * Copyright (c) 1990, 1993 4 * The Regents of the University of California. All rights reserved. 5 * 6 * This code is derived from software contributed to Berkeley by 7 * the University of Utah, and William Jolitz. 8 * 9 * Redistribution and use in source and binary forms, with or without 10 * modification, are permitted provided that the following conditions 11 * are met: 12 * 1. Redistributions of source code must retain the above copyright 13 * notice, this list of conditions and the following disclaimer. 14 * 2. Redistributions in binary form must reproduce the above copyright 15 * notice, this list of conditions and the following disclaimer in the 16 * documentation and/or other materials provided with the distribution. 17 * 3. All advertising materials mentioning features or use of this software 18 * must display the following acknowledgement: 19 * This product includes software developed by the University of 20 * California, Berkeley and its contributors. 21 * 4. Neither the name of the University nor the names of its contributors 22 * may be used to endorse or promote products derived from this software 23 * without specific prior written permission. 24 * 25 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 26 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 27 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 28 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 29 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 30 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 31 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 32 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 33 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 34 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 35 * SUCH DAMAGE. 36 */ 37 38#include <sys/cdefs.h> 39__FBSDID("$FreeBSD: head/sys/amd64/ia32/ia32_syscall.c 200444 2009-12-12 20:11:31Z kib $"); 40 41/* 42 * 386 Trap and System call handling 43 */ 44 45#include "opt_clock.h" 46#include "opt_cpu.h" 47#include "opt_isa.h" 48#include "opt_ktrace.h" 49 50#include <sys/param.h> 51#include <sys/bus.h> 52#include <sys/systm.h> 53#include <sys/proc.h> 54#include <sys/pioctl.h> 55#include <sys/kernel.h> 56#include <sys/ktr.h> 57#include <sys/lock.h> 58#include <sys/mutex.h> 59#include <sys/ptrace.h> 60#include <sys/resourcevar.h> 61#include <sys/signalvar.h> 62#include <sys/syscall.h> 63#include <sys/sysctl.h> 64#include <sys/sysent.h> 65#include <sys/uio.h> 66#include <sys/vmmeter.h> 67#ifdef KTRACE 68#include <sys/ktrace.h> 69#endif 70#include <security/audit/audit.h> 71 72#include <vm/vm.h> 73#include <vm/vm_param.h> 74#include <vm/pmap.h> 75#include <vm/vm_kern.h> 76#include <vm/vm_map.h> 77#include <vm/vm_page.h> 78#include <vm/vm_extern.h> 79 80#include <machine/cpu.h> 81#include <machine/intr_machdep.h> 82#include <machine/md_var.h> 83 84#define IDTVEC(name) __CONCAT(X,name) 85 86extern inthand_t IDTVEC(int0x80_syscall), IDTVEC(rsvd); 87extern const char *freebsd32_syscallnames[]; 88 89void ia32_syscall(struct trapframe *frame); /* Called from asm code */ 90 91void 92ia32_syscall(struct trapframe *frame) 93{ 94 caddr_t params; 95 int i; 96 struct sysent *callp; 97 struct thread *td = curthread; 98 struct proc *p = td->td_proc; 99 register_t orig_tf_rflags; 100 int error; 101 int narg; 102 u_int32_t args[8]; 103 u_int64_t args64[8]; 104 u_int code; 105 ksiginfo_t ksi; 106 107 PCPU_INC(cnt.v_syscall); 108 td->td_pticks = 0; 109 td->td_frame = frame; 110 if (td->td_ucred != p->p_ucred) 111 cred_update_thread(td); 112 params = (caddr_t)frame->tf_rsp + sizeof(u_int32_t); 113 code = frame->tf_rax; 114 orig_tf_rflags = frame->tf_rflags; 115 116 if (p->p_sysent->sv_prepsyscall) { 117 /* 118 * The prep code is MP aware. 119 */ 120 (*p->p_sysent->sv_prepsyscall)(frame, args, &code, ¶ms); 121 } else { 122 /* 123 * Need to check if this is a 32 bit or 64 bit syscall. 124 * fuword is MP aware. 125 */ 126 if (code == SYS_syscall) { 127 /* 128 * Code is first argument, followed by actual args. 129 */ 130 code = fuword32(params); 131 params += sizeof(int); 132 } else if (code == SYS___syscall) { 133 /* 134 * Like syscall, but code is a quad, so as to maintain 135 * quad alignment for the rest of the arguments. 136 * We use a 32-bit fetch in case params is not 137 * aligned. 138 */ 139 code = fuword32(params); 140 params += sizeof(quad_t); 141 } 142 } 143 144 if (p->p_sysent->sv_mask) 145 code &= p->p_sysent->sv_mask; 146 147 if (code >= p->p_sysent->sv_size) 148 callp = &p->p_sysent->sv_table[0]; 149 else 150 callp = &p->p_sysent->sv_table[code]; 151 152 narg = callp->sy_narg; 153 154 /* 155 * copyin and the ktrsyscall()/ktrsysret() code is MP-aware 156 */ 157 if (params != NULL && narg != 0) 158 error = copyin(params, (caddr_t)args, 159 (u_int)(narg * sizeof(int))); 160 else 161 error = 0; 162 163 for (i = 0; i < narg; i++) 164 args64[i] = args[i]; 165 166#ifdef KTRACE 167 if (KTRPOINT(td, KTR_SYSCALL)) 168 ktrsyscall(code, narg, args64); 169#endif 170 CTR4(KTR_SYSC, "syscall enter thread %p pid %d proc %s code %d", td, 171 td->td_proc->p_pid, td->td_proc->p_comm, code); 172 173 if (error == 0) { 174 td->td_retval[0] = 0; 175 td->td_retval[1] = frame->tf_rdx; 176 177 STOPEVENT(p, S_SCE, narg); 178 179 PTRACESTOP_SC(p, td, S_PT_SCE); 180 181 AUDIT_SYSCALL_ENTER(code, td); 182 error = (*callp->sy_call)(td, args64); 183 AUDIT_SYSCALL_EXIT(error, td); 184 } 185 186 cpu_set_syscall_retval(td, error); 187 188 /* 189 * Traced syscall. 190 */ 191 if (orig_tf_rflags & PSL_T) { 192 frame->tf_rflags &= ~PSL_T; 193 ksiginfo_init_trap(&ksi); 194 ksi.ksi_signo = SIGTRAP; 195 ksi.ksi_code = TRAP_TRACE; 196 ksi.ksi_addr = (void *)frame->tf_rip; 197 trapsignal(td, &ksi); 198 } 199 200 /* 201 * Check for misbehavior. 202 */ 203 WITNESS_WARN(WARN_PANIC, NULL, "System call %s returning", 204 (code >= 0 && code < SYS_MAXSYSCALL) ? freebsd32_syscallnames[code] : "???"); 205 KASSERT(td->td_critnest == 0, 206 ("System call %s returning in a critical section", 207 (code >= 0 && code < SYS_MAXSYSCALL) ? freebsd32_syscallnames[code] : "???")); 208 KASSERT(td->td_locks == 0, 209 ("System call %s returning with %d locks held", 210 (code >= 0 && code < SYS_MAXSYSCALL) ? freebsd32_syscallnames[code] : "???", 211 td->td_locks)); 212 213 /* 214 * Handle reschedule and other end-of-syscall issues 215 */ 216 userret(td, frame); 217 218 CTR4(KTR_SYSC, "syscall exit thread %p pid %d proc %s code %d", td, 219 td->td_proc->p_pid, td->td_proc->p_comm, code); 220#ifdef KTRACE 221 if (KTRPOINT(td, KTR_SYSRET)) 222 ktrsysret(code, error, td->td_retval[0]); 223#endif 224 225 /* 226 * This works because errno is findable through the 227 * register set. If we ever support an emulation where this 228 * is not the case, this code will need to be revisited. 229 */ 230 STOPEVENT(p, S_SCX, code); 231 232 PTRACESTOP_SC(p, td, S_PT_SCX); 233} 234 235 236static void 237ia32_syscall_enable(void *dummy) 238{ 239 240 setidt(IDT_SYSCALL, &IDTVEC(int0x80_syscall), SDT_SYSIGT, SEL_UPL, 0); 241} 242 243static void 244ia32_syscall_disable(void *dummy) 245{ 246 247 setidt(IDT_SYSCALL, &IDTVEC(rsvd), SDT_SYSIGT, SEL_KPL, 0); 248} 249 250SYSINIT(ia32_syscall, SI_SUB_EXEC, SI_ORDER_ANY, ia32_syscall_enable, NULL); 251SYSUNINIT(ia32_syscall, SI_SUB_EXEC, SI_ORDER_ANY, ia32_syscall_disable, NULL); 252