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("$FreeBSD$"); 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 86 extern inthand_t IDTVEC(int0x80_syscall), IDTVEC(rsvd); 87 extern const char *freebsd32_syscallnames[]; 88 89 void ia32_syscall(struct trapframe *frame); /* Called from asm code */ 90 91 struct ia32_syscall_args { 92 u_int code; 93 caddr_t params; 94 struct sysent *callp; 95 u_int64_t args64[8]; 96 int narg; 97 }; 98 99 static int 100 fetch_ia32_syscall_args(struct thread *td, struct ia32_syscall_args *sa) 101 { 102 struct proc *p; 103 struct trapframe *frame; 104 u_int32_t args[8]; 105 int error, i; 106 107 p = td->td_proc; 108 frame = td->td_frame; 109 110 sa->params = (caddr_t)frame->tf_rsp + sizeof(u_int32_t); 111 sa->code = frame->tf_rax; 112 113 if (p->p_sysent->sv_prepsyscall) { 114 /* 115 * The prep code is MP aware. 116 */ 117 (*p->p_sysent->sv_prepsyscall)(frame, args, &sa->code, 118 &sa->params); 119 } else { 120 /* 121 * Need to check if this is a 32 bit or 64 bit syscall. 122 * fuword is MP aware. 123 */ 124 if (sa->code == SYS_syscall) { 125 /* 126 * Code is first argument, followed by actual args. 127 */ 128 sa->code = fuword32(sa->params); 129 sa->params += sizeof(int); 130 } else if (sa->code == SYS___syscall) { 131 /* 132 * Like syscall, but code is a quad, so as to maintain 133 * quad alignment for the rest of the arguments. 134 * We use a 32-bit fetch in case params is not 135 * aligned. 136 */ 137 sa->code = fuword32(sa->params); 138 sa->params += sizeof(quad_t); 139 } 140 } 141 if (p->p_sysent->sv_mask) 142 sa->code &= p->p_sysent->sv_mask; 143 if (sa->code >= p->p_sysent->sv_size) 144 sa->callp = &p->p_sysent->sv_table[0]; 145 else 146 sa->callp = &p->p_sysent->sv_table[sa->code]; 147 sa->narg = sa->callp->sy_narg; 148 149 if (sa->params != NULL && sa->narg != 0) 150 error = copyin(sa->params, (caddr_t)args, 151 (u_int)(sa->narg * sizeof(int))); 152 else 153 error = 0; 154 155 for (i = 0; i < sa->narg; i++) 156 sa->args64[i] = args[i]; 157 158 #ifdef KTRACE 159 if (KTRPOINT(td, KTR_SYSCALL)) 160 ktrsyscall(sa->code, sa->narg, sa->args64); 161 #endif 162 163 return (error); 164 } 165 166 void 167 ia32_syscall(struct trapframe *frame) 168 { 169 struct thread *td; 170 struct proc *p; 171 struct ia32_syscall_args sa; 172 register_t orig_tf_rflags; 173 int error; 174 ksiginfo_t ksi; 175 176 PCPU_INC(cnt.v_syscall); 177 td = curthread; 178 p = td->td_proc; 179 td->td_syscalls++; 180 181 td->td_pticks = 0; 182 td->td_frame = frame; 183 if (td->td_ucred != p->p_ucred) 184 cred_update_thread(td); 185 orig_tf_rflags = frame->tf_rflags; 186 if (p->p_flag & P_TRACED) { 187 PROC_LOCK(p); 188 td->td_dbgflags &= ~TDB_USERWR; 189 PROC_UNLOCK(p); 190 } 191 error = fetch_ia32_syscall_args(td, &sa); 192 193 CTR4(KTR_SYSC, "syscall enter thread %p pid %d proc %s code %d", td, 194 td->td_proc->p_pid, td->td_name, sa.code); 195 196 if (error == 0) { 197 td->td_retval[0] = 0; 198 td->td_retval[1] = frame->tf_rdx; 199 200 STOPEVENT(p, S_SCE, sa.narg); 201 PTRACESTOP_SC(p, td, S_PT_SCE); 202 if (td->td_dbgflags & TDB_USERWR) { 203 /* 204 * Reread syscall number and arguments if 205 * debugger modified registers or memory. 206 */ 207 error = fetch_ia32_syscall_args(td, &sa); 208 if (error != 0) 209 goto retval; 210 td->td_retval[1] = frame->tf_rdx; 211 } 212 213 AUDIT_SYSCALL_ENTER(sa.code, td); 214 error = (*sa.callp->sy_call)(td, sa.args64); 215 AUDIT_SYSCALL_EXIT(error, td); 216 217 /* Save the latest error return value. */ 218 td->td_errno = error; 219 } 220 retval: 221 cpu_set_syscall_retval(td, error); 222 223 /* 224 * Traced syscall. 225 */ 226 if (orig_tf_rflags & PSL_T) { 227 frame->tf_rflags &= ~PSL_T; 228 ksiginfo_init_trap(&ksi); 229 ksi.ksi_signo = SIGTRAP; 230 ksi.ksi_code = TRAP_TRACE; 231 ksi.ksi_addr = (void *)frame->tf_rip; 232 trapsignal(td, &ksi); 233 } 234 235 /* 236 * Check for misbehavior. 237 */ 238 WITNESS_WARN(WARN_PANIC, NULL, "System call %s returning", 239 (sa.code >= 0 && sa.code < SYS_MAXSYSCALL) ? 240 freebsd32_syscallnames[sa.code] : "???"); 241 KASSERT(td->td_critnest == 0, 242 ("System call %s returning in a critical section", 243 (sa.code >= 0 && sa.code < SYS_MAXSYSCALL) ? 244 freebsd32_syscallnames[sa.code] : "???")); 245 KASSERT(td->td_locks == 0, 246 ("System call %s returning with %d locks held", 247 (sa.code >= 0 && sa.code < SYS_MAXSYSCALL) ? 248 freebsd32_syscallnames[sa.code] : "???", td->td_locks)); 249 250 /* 251 * Handle reschedule and other end-of-syscall issues 252 */ 253 userret(td, frame); 254 255 CTR4(KTR_SYSC, "syscall exit thread %p pid %d proc %s code %d", td, 256 td->td_proc->p_pid, td->td_proc->p_comm, sa.code); 257 #ifdef KTRACE 258 if (KTRPOINT(td, KTR_SYSRET)) 259 ktrsysret(sa.code, error, td->td_retval[0]); 260 #endif 261 262 /* 263 * This works because errno is findable through the 264 * register set. If we ever support an emulation where this 265 * is not the case, this code will need to be revisited. 266 */ 267 STOPEVENT(p, S_SCX, sa.code); 268 269 PTRACESTOP_SC(p, td, S_PT_SCX); 270 } 271 272 273 static void 274 ia32_syscall_enable(void *dummy) 275 { 276 277 setidt(IDT_SYSCALL, &IDTVEC(int0x80_syscall), SDT_SYSIGT, SEL_UPL, 0); 278 } 279 280 static void 281 ia32_syscall_disable(void *dummy) 282 { 283 284 setidt(IDT_SYSCALL, &IDTVEC(rsvd), SDT_SYSIGT, SEL_KPL, 0); 285 } 286 287 SYSINIT(ia32_syscall, SI_SUB_EXEC, SI_ORDER_ANY, ia32_syscall_enable, NULL); 288 SYSUNINIT(ia32_syscall, SI_SUB_EXEC, SI_ORDER_ANY, ia32_syscall_disable, NULL); 289