ia32_syscall.c revision 144971
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 144971 2005-04-12 23:18:54Z jhb $"); 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 70#include <vm/vm.h> 71#include <vm/vm_param.h> 72#include <vm/pmap.h> 73#include <vm/vm_kern.h> 74#include <vm/vm_map.h> 75#include <vm/vm_page.h> 76#include <vm/vm_extern.h> 77 78#include <machine/cpu.h> 79#include <machine/intr_machdep.h> 80#include <machine/md_var.h> 81 82#define IDTVEC(name) __CONCAT(X,name) 83 84extern inthand_t IDTVEC(int0x80_syscall), IDTVEC(rsvd); 85extern const char *freebsd32_syscallnames[]; 86 87void ia32_syscall(struct trapframe frame); /* Called from asm code */ 88 89void 90ia32_syscall(struct trapframe frame) 91{ 92 caddr_t params; 93 int i; 94 struct sysent *callp; 95 struct thread *td = curthread; 96 struct proc *p = td->td_proc; 97 register_t orig_tf_rflags; 98 u_int sticks; 99 int error; 100 int narg; 101 u_int32_t args[8]; 102 u_int64_t args64[8]; 103 u_int code; 104 105 /* 106 * note: PCPU_LAZY_INC() can only be used if we can afford 107 * occassional inaccuracy in the count. 108 */ 109 PCPU_LAZY_INC(cnt.v_syscall); 110 111 sticks = td->td_sticks; 112 td->td_frame = &frame; 113 if (td->td_ucred != p->p_ucred) 114 cred_update_thread(td); 115 params = (caddr_t)frame.tf_rsp + sizeof(u_int32_t); 116 code = frame.tf_rax; 117 orig_tf_rflags = frame.tf_rflags; 118 119 if (p->p_sysent->sv_prepsyscall) { 120 /* 121 * The prep code is MP aware. 122 */ 123 (*p->p_sysent->sv_prepsyscall)(&frame, args, &code, ¶ms); 124 } else { 125 /* 126 * Need to check if this is a 32 bit or 64 bit syscall. 127 * fuword is MP aware. 128 */ 129 if (code == SYS_syscall) { 130 /* 131 * Code is first argument, followed by actual args. 132 */ 133 code = fuword32(params); 134 params += sizeof(int); 135 } else if (code == SYS___syscall) { 136 /* 137 * Like syscall, but code is a quad, so as to maintain 138 * quad alignment for the rest of the arguments. 139 * We use a 32-bit fetch in case params is not 140 * aligned. 141 */ 142 code = fuword32(params); 143 params += sizeof(quad_t); 144 } 145 } 146 147 if (p->p_sysent->sv_mask) 148 code &= p->p_sysent->sv_mask; 149 150 if (code >= p->p_sysent->sv_size) 151 callp = &p->p_sysent->sv_table[0]; 152 else 153 callp = &p->p_sysent->sv_table[code]; 154 155 narg = callp->sy_narg & SYF_ARGMASK; 156 157 /* 158 * copyin and the ktrsyscall()/ktrsysret() code is MP-aware 159 */ 160 if (params != NULL && narg != 0) 161 error = copyin(params, (caddr_t)args, 162 (u_int)(narg * sizeof(int))); 163 else 164 error = 0; 165 166 for (i = 0; i < narg; i++) 167 args64[i] = args[i]; 168 169#ifdef KTRACE 170 if (KTRPOINT(td, KTR_SYSCALL)) 171 ktrsyscall(code, narg, args64); 172#endif 173 /* 174 * Try to run the syscall without Giant if the syscall 175 * is MP safe. 176 */ 177 if ((callp->sy_narg & SYF_MPSAFE) == 0) 178 mtx_lock(&Giant); 179 180 if (error == 0) { 181 td->td_retval[0] = 0; 182 td->td_retval[1] = frame.tf_rdx; 183 184 STOPEVENT(p, S_SCE, narg); 185 186 error = (*callp->sy_call)(td, args64); 187 } 188 189 switch (error) { 190 case 0: 191 frame.tf_rax = td->td_retval[0]; 192 frame.tf_rdx = td->td_retval[1]; 193 frame.tf_rflags &= ~PSL_C; 194 break; 195 196 case ERESTART: 197 /* 198 * Reconstruct pc, assuming lcall $X,y is 7 bytes, 199 * int 0x80 is 2 bytes. We saved this in tf_err. 200 */ 201 frame.tf_rip -= frame.tf_err; 202 break; 203 204 case EJUSTRETURN: 205 break; 206 207 default: 208 if (p->p_sysent->sv_errsize) { 209 if (error >= p->p_sysent->sv_errsize) 210 error = -1; /* XXX */ 211 else 212 error = p->p_sysent->sv_errtbl[error]; 213 } 214 frame.tf_rax = error; 215 frame.tf_rflags |= PSL_C; 216 break; 217 } 218 219 /* 220 * Release Giant if we previously set it. 221 */ 222 if ((callp->sy_narg & SYF_MPSAFE) == 0) 223 mtx_unlock(&Giant); 224 225 /* 226 * Traced syscall. 227 */ 228 if (orig_tf_rflags & PSL_T) { 229 frame.tf_rflags &= ~PSL_T; 230 trapsignal(td, SIGTRAP, 0); 231 } 232 233 /* 234 * Handle reschedule and other end-of-syscall issues 235 */ 236 userret(td, &frame, sticks); 237 238#ifdef KTRACE 239 if (KTRPOINT(td, KTR_SYSRET)) 240 ktrsysret(code, error, td->td_retval[0]); 241#endif 242 243 /* 244 * This works because errno is findable through the 245 * register set. If we ever support an emulation where this 246 * is not the case, this code will need to be revisited. 247 */ 248 STOPEVENT(p, S_SCX, code); 249 250 WITNESS_WARN(WARN_PANIC, NULL, "System call %s returning", 251 (code >= 0 && code < SYS_MAXSYSCALL) ? freebsd32_syscallnames[code] : "???"); 252 mtx_assert(&sched_lock, MA_NOTOWNED); 253 mtx_assert(&Giant, MA_NOTOWNED); 254} 255 256 257static void 258ia32_syscall_enable(void *dummy) 259{ 260 261 setidt(IDT_SYSCALL, &IDTVEC(int0x80_syscall), SDT_SYSIGT, SEL_UPL, 0); 262} 263 264static void 265ia32_syscall_disable(void *dummy) 266{ 267 268 setidt(IDT_SYSCALL, &IDTVEC(rsvd), SDT_SYSIGT, SEL_KPL, 0); 269} 270 271SYSINIT(ia32_syscall, SI_SUB_EXEC, SI_ORDER_ANY, ia32_syscall_enable, NULL); 272SYSUNINIT(ia32_syscall, SI_SUB_EXEC, SI_ORDER_ANY, ia32_syscall_disable, NULL); 273