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 void 92 ia32_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 /* 108 * note: PCPU_LAZY_INC() can only be used if we can afford 109 * occassional inaccuracy in the count. 110 */ 111 PCPU_LAZY_INC(cnt.v_syscall); 112 113 td->td_pticks = 0; 114 td->td_frame = frame; 115 if (td->td_ucred != p->p_ucred) 116 cred_update_thread(td); 117 params = (caddr_t)frame->tf_rsp + sizeof(u_int32_t); 118 code = frame->tf_rax; 119 orig_tf_rflags = frame->tf_rflags; 120 121 if (p->p_sysent->sv_prepsyscall) { 122 /* 123 * The prep code is MP aware. 124 */ 125 (*p->p_sysent->sv_prepsyscall)(frame, args, &code, ¶ms); 126 } else { 127 /* 128 * Need to check if this is a 32 bit or 64 bit syscall. 129 * fuword is MP aware. 130 */ 131 if (code == SYS_syscall) { 132 /* 133 * Code is first argument, followed by actual args. 134 */ 135 code = fuword32(params); 136 params += sizeof(int); 137 } else if (code == SYS___syscall) { 138 /* 139 * Like syscall, but code is a quad, so as to maintain 140 * quad alignment for the rest of the arguments. 141 * We use a 32-bit fetch in case params is not 142 * aligned. 143 */ 144 code = fuword32(params); 145 params += sizeof(quad_t); 146 } 147 } 148 149 if (p->p_sysent->sv_mask) 150 code &= p->p_sysent->sv_mask; 151 152 if (code >= p->p_sysent->sv_size) 153 callp = &p->p_sysent->sv_table[0]; 154 else 155 callp = &p->p_sysent->sv_table[code]; 156 157 narg = callp->sy_narg; 158 159 /* 160 * copyin and the ktrsyscall()/ktrsysret() code is MP-aware 161 */ 162 if (params != NULL && narg != 0) 163 error = copyin(params, (caddr_t)args, 164 (u_int)(narg * sizeof(int))); 165 else 166 error = 0; 167 168 for (i = 0; i < narg; i++) 169 args64[i] = args[i]; 170 171 #ifdef KTRACE 172 if (KTRPOINT(td, KTR_SYSCALL)) 173 ktrsyscall(code, narg, args64); 174 #endif 175 CTR4(KTR_SYSC, "syscall enter thread %p pid %d proc %s code %d", td, 176 td->td_proc->p_pid, td->td_proc->p_comm, code); 177 178 if (error == 0) { 179 td->td_retval[0] = 0; 180 td->td_retval[1] = frame->tf_rdx; 181 182 STOPEVENT(p, S_SCE, narg); 183 184 PTRACESTOP_SC(p, td, S_PT_SCE); 185 186 AUDIT_SYSCALL_ENTER(code, td); 187 error = (*callp->sy_call)(td, args64); 188 AUDIT_SYSCALL_EXIT(error, td); 189 } 190 191 switch (error) { 192 case 0: 193 frame->tf_rax = td->td_retval[0]; 194 frame->tf_rdx = td->td_retval[1]; 195 frame->tf_rflags &= ~PSL_C; 196 break; 197 198 case ERESTART: 199 /* 200 * Reconstruct pc, assuming lcall $X,y is 7 bytes, 201 * int 0x80 is 2 bytes. We saved this in tf_err. 202 */ 203 frame->tf_rip -= frame->tf_err; 204 break; 205 206 case EJUSTRETURN: 207 break; 208 209 default: 210 if (p->p_sysent->sv_errsize) { 211 if (error >= p->p_sysent->sv_errsize) 212 error = -1; /* XXX */ 213 else 214 error = p->p_sysent->sv_errtbl[error]; 215 } 216 frame->tf_rax = error; 217 frame->tf_rflags |= PSL_C; 218 break; 219 } 220 221 /* 222 * Traced syscall. 223 */ 224 if (orig_tf_rflags & PSL_T) { 225 frame->tf_rflags &= ~PSL_T; 226 ksiginfo_init_trap(&ksi); 227 ksi.ksi_signo = SIGTRAP; 228 ksi.ksi_code = TRAP_TRACE; 229 ksi.ksi_addr = (void *)frame->tf_rip; 230 trapsignal(td, &ksi); 231 } 232 233 /* 234 * Check for misbehavior. 235 */ 236 WITNESS_WARN(WARN_PANIC, NULL, "System call %s returning", 237 (code >= 0 && code < SYS_MAXSYSCALL) ? freebsd32_syscallnames[code] : "???"); 238 KASSERT(td->td_critnest == 0, 239 ("System call %s returning in a critical section", 240 (code >= 0 && code < SYS_MAXSYSCALL) ? freebsd32_syscallnames[code] : "???")); 241 KASSERT(td->td_locks == 0, 242 ("System call %s returning with %d locks held", 243 (code >= 0 && code < SYS_MAXSYSCALL) ? freebsd32_syscallnames[code] : "???", 244 td->td_locks)); 245 246 /* 247 * Handle reschedule and other end-of-syscall issues 248 */ 249 userret(td, frame); 250 251 CTR4(KTR_SYSC, "syscall exit thread %p pid %d proc %s code %d", td, 252 td->td_proc->p_pid, td->td_proc->p_comm, code); 253 #ifdef KTRACE 254 if (KTRPOINT(td, KTR_SYSRET)) 255 ktrsysret(code, error, td->td_retval[0]); 256 #endif 257 258 /* 259 * This works because errno is findable through the 260 * register set. If we ever support an emulation where this 261 * is not the case, this code will need to be revisited. 262 */ 263 STOPEVENT(p, S_SCX, code); 264 265 PTRACESTOP_SC(p, td, S_PT_SCX); 266 } 267 268 269 static void 270 ia32_syscall_enable(void *dummy) 271 { 272 273 setidt(IDT_SYSCALL, &IDTVEC(int0x80_syscall), SDT_SYSIGT, SEL_UPL, 0); 274 } 275 276 static void 277 ia32_syscall_disable(void *dummy) 278 { 279 280 setidt(IDT_SYSCALL, &IDTVEC(rsvd), SDT_SYSIGT, SEL_KPL, 0); 281 } 282 283 SYSINIT(ia32_syscall, SI_SUB_EXEC, SI_ORDER_ANY, ia32_syscall_enable, NULL); 284 SYSUNINIT(ia32_syscall, SI_SUB_EXEC, SI_ORDER_ANY, ia32_syscall_disable, NULL); 285