ia32_syscall.c revision 155455
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 155455 2006-02-08 08:09:17Z phk $"); 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/resourcevar.h> 60#include <sys/signalvar.h> 61#include <sys/syscall.h> 62#include <sys/sysctl.h> 63#include <sys/sysent.h> 64#include <sys/uio.h> 65#include <sys/vmmeter.h> 66#ifdef KTRACE 67#include <sys/ktrace.h> 68#endif 69#include <security/audit/audit.h> 70 71#include <vm/vm.h> 72#include <vm/vm_param.h> 73#include <vm/pmap.h> 74#include <vm/vm_kern.h> 75#include <vm/vm_map.h> 76#include <vm/vm_page.h> 77#include <vm/vm_extern.h> 78 79#include <machine/cpu.h> 80#include <machine/intr_machdep.h> 81#include <machine/md_var.h> 82 83#define IDTVEC(name) __CONCAT(X,name) 84 85extern inthand_t IDTVEC(int0x80_syscall), IDTVEC(rsvd); 86extern const char *freebsd32_syscallnames[]; 87 88void ia32_syscall(struct trapframe frame); /* Called from asm code */ 89 90void 91ia32_syscall(struct trapframe frame) 92{ 93 caddr_t params; 94 int i; 95 struct sysent *callp; 96 struct thread *td = curthread; 97 struct proc *p = td->td_proc; 98 register_t orig_tf_rflags; 99 int error; 100 int narg; 101 u_int32_t args[8]; 102 u_int64_t args64[8]; 103 u_int code; 104 ksiginfo_t ksi; 105 106 /* 107 * note: PCPU_LAZY_INC() can only be used if we can afford 108 * occassional inaccuracy in the count. 109 */ 110 PCPU_LAZY_INC(cnt.v_syscall); 111 112 td->td_pticks = 0; 113 td->td_frame = &frame; 114 if (td->td_ucred != p->p_ucred) 115 cred_update_thread(td); 116 params = (caddr_t)frame.tf_rsp + sizeof(u_int32_t); 117 code = frame.tf_rax; 118 orig_tf_rflags = frame.tf_rflags; 119 120 if (p->p_sysent->sv_prepsyscall) { 121 /* 122 * The prep code is MP aware. 123 */ 124 (*p->p_sysent->sv_prepsyscall)(&frame, args, &code, ¶ms); 125 } else { 126 /* 127 * Need to check if this is a 32 bit or 64 bit syscall. 128 * fuword is MP aware. 129 */ 130 if (code == SYS_syscall) { 131 /* 132 * Code is first argument, followed by actual args. 133 */ 134 code = fuword32(params); 135 params += sizeof(int); 136 } else if (code == SYS___syscall) { 137 /* 138 * Like syscall, but code is a quad, so as to maintain 139 * quad alignment for the rest of the arguments. 140 * We use a 32-bit fetch in case params is not 141 * aligned. 142 */ 143 code = fuword32(params); 144 params += sizeof(quad_t); 145 } 146 } 147 148 if (p->p_sysent->sv_mask) 149 code &= p->p_sysent->sv_mask; 150 151 if (code >= p->p_sysent->sv_size) 152 callp = &p->p_sysent->sv_table[0]; 153 else 154 callp = &p->p_sysent->sv_table[code]; 155 156 narg = callp->sy_narg & SYF_ARGMASK; 157 158 /* 159 * copyin and the ktrsyscall()/ktrsysret() code is MP-aware 160 */ 161 if (params != NULL && narg != 0) 162 error = copyin(params, (caddr_t)args, 163 (u_int)(narg * sizeof(int))); 164 else 165 error = 0; 166 167 for (i = 0; i < narg; i++) 168 args64[i] = args[i]; 169 170#ifdef KTRACE 171 if (KTRPOINT(td, KTR_SYSCALL)) 172 ktrsyscall(code, narg, args64); 173#endif 174 /* 175 * Try to run the syscall without Giant if the syscall 176 * is MP safe. 177 */ 178 if ((callp->sy_narg & SYF_MPSAFE) == 0) 179 mtx_lock(&Giant); 180 181 if (error == 0) { 182 td->td_retval[0] = 0; 183 td->td_retval[1] = frame.tf_rdx; 184 185 STOPEVENT(p, S_SCE, narg); 186 187 AUDIT_SYSCALL_ENTER(code, td); 188 error = (*callp->sy_call)(td, args64); 189 AUDIT_SYSCALL_EXIT(error, td); 190 } 191 192 switch (error) { 193 case 0: 194 frame.tf_rax = td->td_retval[0]; 195 frame.tf_rdx = td->td_retval[1]; 196 frame.tf_rflags &= ~PSL_C; 197 break; 198 199 case ERESTART: 200 /* 201 * Reconstruct pc, assuming lcall $X,y is 7 bytes, 202 * int 0x80 is 2 bytes. We saved this in tf_err. 203 */ 204 frame.tf_rip -= frame.tf_err; 205 break; 206 207 case EJUSTRETURN: 208 break; 209 210 default: 211 if (p->p_sysent->sv_errsize) { 212 if (error >= p->p_sysent->sv_errsize) 213 error = -1; /* XXX */ 214 else 215 error = p->p_sysent->sv_errtbl[error]; 216 } 217 frame.tf_rax = error; 218 frame.tf_rflags |= PSL_C; 219 break; 220 } 221 222 /* 223 * Release Giant if we previously set it. 224 */ 225 if ((callp->sy_narg & SYF_MPSAFE) == 0) 226 mtx_unlock(&Giant); 227 228 /* 229 * Traced syscall. 230 */ 231 if (orig_tf_rflags & PSL_T) { 232 frame.tf_rflags &= ~PSL_T; 233 ksiginfo_init_trap(&ksi); 234 ksi.ksi_signo = SIGTRAP; 235 ksi.ksi_code = TRAP_TRACE; 236 ksi.ksi_addr = (void *)frame.tf_rip; 237 trapsignal(td, &ksi); 238 } 239 240 /* 241 * Handle reschedule and other end-of-syscall issues 242 */ 243 userret(td, &frame); 244 245#ifdef KTRACE 246 if (KTRPOINT(td, KTR_SYSRET)) 247 ktrsysret(code, error, td->td_retval[0]); 248#endif 249 250 /* 251 * This works because errno is findable through the 252 * register set. If we ever support an emulation where this 253 * is not the case, this code will need to be revisited. 254 */ 255 STOPEVENT(p, S_SCX, code); 256 257 WITNESS_WARN(WARN_PANIC, NULL, "System call %s returning", 258 (code >= 0 && code < SYS_MAXSYSCALL) ? freebsd32_syscallnames[code] : "???"); 259 mtx_assert(&sched_lock, MA_NOTOWNED); 260 mtx_assert(&Giant, MA_NOTOWNED); 261} 262 263 264static void 265ia32_syscall_enable(void *dummy) 266{ 267 268 setidt(IDT_SYSCALL, &IDTVEC(int0x80_syscall), SDT_SYSIGT, SEL_UPL, 0); 269} 270 271static void 272ia32_syscall_disable(void *dummy) 273{ 274 275 setidt(IDT_SYSCALL, &IDTVEC(rsvd), SDT_SYSIGT, SEL_KPL, 0); 276} 277 278SYSINIT(ia32_syscall, SI_SUB_EXEC, SI_ORDER_ANY, ia32_syscall_enable, NULL); 279SYSUNINIT(ia32_syscall, SI_SUB_EXEC, SI_ORDER_ANY, ia32_syscall_disable, NULL); 280