1 /*- 2 * SPDX-License-Identifier: BSD-4-Clause 3 * 4 * Copyright (C) 1994, David Greenman 5 * Copyright (c) 1990, 1993 6 * The Regents of the University of California. All rights reserved. 7 * 8 * This code is derived from software contributed to Berkeley by 9 * the University of Utah, and William Jolitz. 10 * 11 * Redistribution and use in source and binary forms, with or without 12 * modification, are permitted provided that the following conditions 13 * are met: 14 * 1. Redistributions of source code must retain the above copyright 15 * notice, this list of conditions and the following disclaimer. 16 * 2. Redistributions in binary form must reproduce the above copyright 17 * notice, this list of conditions and the following disclaimer in the 18 * documentation and/or other materials provided with the distribution. 19 * 3. All advertising materials mentioning features or use of this software 20 * must display the following acknowledgement: 21 * This product includes software developed by the University of 22 * California, Berkeley and its contributors. 23 * 4. Neither the name of the University nor the names of its contributors 24 * may be used to endorse or promote products derived from this software 25 * without specific prior written permission. 26 * 27 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 28 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 29 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 30 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 31 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 32 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 33 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 34 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 35 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 36 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 37 * SUCH DAMAGE. 38 */ 39 40 #include <sys/cdefs.h> 41 __FBSDID("$FreeBSD$"); 42 43 /* 44 * 386 Trap and System call handling 45 */ 46 47 #include "opt_clock.h" 48 #include "opt_cpu.h" 49 #include "opt_isa.h" 50 51 #include <sys/param.h> 52 #include <sys/bus.h> 53 #include <sys/systm.h> 54 #include <sys/proc.h> 55 #include <sys/kernel.h> 56 #include <sys/ktr.h> 57 #include <sys/lock.h> 58 #include <sys/msan.h> 59 #include <sys/mutex.h> 60 #include <sys/proc.h> 61 #include <sys/ptrace.h> 62 #include <sys/resourcevar.h> 63 #include <sys/signalvar.h> 64 #include <sys/syscall.h> 65 #include <sys/sysctl.h> 66 #include <sys/sysent.h> 67 #include <sys/uio.h> 68 #include <sys/vmmeter.h> 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 #include <compat/freebsd32/freebsd32_signal.h> 84 #include <compat/freebsd32/freebsd32_util.h> 85 #include <compat/ia32/ia32_signal.h> 86 #include <machine/psl.h> 87 #include <machine/segments.h> 88 #include <machine/specialreg.h> 89 #include <machine/sysarch.h> 90 #include <machine/frame.h> 91 #include <machine/md_var.h> 92 #include <machine/pcb.h> 93 #include <machine/cpufunc.h> 94 95 #define IDTVEC(name) __CONCAT(X,name) 96 97 extern inthand_t IDTVEC(int0x80_syscall), IDTVEC(int0x80_syscall_pti), 98 IDTVEC(rsvd), IDTVEC(rsvd_pti); 99 100 void ia32_syscall(struct trapframe *frame); /* Called from asm code */ 101 102 void 103 ia32_set_syscall_retval(struct thread *td, int error) 104 { 105 106 cpu_set_syscall_retval(td, error); 107 } 108 109 int 110 ia32_fetch_syscall_args(struct thread *td) 111 { 112 struct proc *p; 113 struct trapframe *frame; 114 struct syscall_args *sa; 115 caddr_t params; 116 u_int32_t args[8], tmp; 117 int error, i; 118 #ifdef COMPAT_43 119 u_int32_t eip; 120 int cs; 121 #endif 122 123 p = td->td_proc; 124 frame = td->td_frame; 125 sa = &td->td_sa; 126 127 #ifdef COMPAT_43 128 if (__predict_false(frame->tf_cs == 7 && frame->tf_rip == 2)) { 129 /* 130 * In lcall $7,$0 after int $0x80. Convert the user 131 * frame to what it would be for a direct int 0x80 instead 132 * of lcall $7,$0, by popping the lcall return address. 133 */ 134 error = fueword32((void *)frame->tf_rsp, &eip); 135 if (error == -1) 136 return (EFAULT); 137 cs = fuword16((void *)(frame->tf_rsp + sizeof(u_int32_t))); 138 if (cs == -1) 139 return (EFAULT); 140 141 /* 142 * Unwind in-kernel frame after all stack frame pieces 143 * were successfully read. 144 */ 145 frame->tf_rip = eip; 146 frame->tf_cs = cs; 147 frame->tf_rsp += 2 * sizeof(u_int32_t); 148 frame->tf_err = 7; /* size of lcall $7,$0 */ 149 } 150 #endif 151 152 params = (caddr_t)frame->tf_rsp + sizeof(u_int32_t); 153 sa->code = frame->tf_rax; 154 sa->original_code = sa->code; 155 156 /* 157 * Need to check if this is a 32 bit or 64 bit syscall. 158 */ 159 if (sa->code == SYS_syscall) { 160 /* 161 * Code is first argument, followed by actual args. 162 */ 163 error = fueword32(params, &tmp); 164 if (error == -1) 165 return (EFAULT); 166 sa->code = tmp; 167 params += sizeof(int); 168 } else if (sa->code == SYS___syscall) { 169 /* 170 * Like syscall, but code is a quad, so as to maintain 171 * quad alignment for the rest of the arguments. 172 * We use a 32-bit fetch in case params is not 173 * aligned. 174 */ 175 error = fueword32(params, &tmp); 176 if (error == -1) 177 return (EFAULT); 178 sa->code = tmp; 179 params += sizeof(quad_t); 180 } 181 if (sa->code >= p->p_sysent->sv_size) 182 sa->callp = &p->p_sysent->sv_table[0]; 183 else 184 sa->callp = &p->p_sysent->sv_table[sa->code]; 185 186 if (params != NULL && sa->callp->sy_narg != 0) 187 error = copyin(params, (caddr_t)args, 188 (u_int)(sa->callp->sy_narg * sizeof(int))); 189 else 190 error = 0; 191 192 for (i = 0; i < sa->callp->sy_narg; i++) 193 sa->args[i] = args[i]; 194 195 if (error == 0) { 196 td->td_retval[0] = 0; 197 td->td_retval[1] = frame->tf_rdx; 198 } 199 200 return (error); 201 } 202 203 #include "../../kern/subr_syscall.c" 204 205 void 206 ia32_syscall(struct trapframe *frame) 207 { 208 struct thread *td; 209 register_t orig_tf_rflags; 210 ksiginfo_t ksi; 211 212 kmsan_mark(frame, sizeof(*frame), KMSAN_STATE_INITED); 213 214 orig_tf_rflags = frame->tf_rflags; 215 td = curthread; 216 td->td_frame = frame; 217 218 syscallenter(td); 219 220 /* 221 * Traced syscall. 222 */ 223 if (orig_tf_rflags & PSL_T) { 224 frame->tf_rflags &= ~PSL_T; 225 ksiginfo_init_trap(&ksi); 226 ksi.ksi_signo = SIGTRAP; 227 ksi.ksi_code = TRAP_TRACE; 228 ksi.ksi_addr = (void *)frame->tf_rip; 229 trapsignal(td, &ksi); 230 } 231 232 syscallret(td); 233 amd64_syscall_ret_flush_l1d(td->td_errno); 234 } 235 236 static void 237 ia32_syscall_enable(void *dummy) 238 { 239 240 setidt(IDT_SYSCALL, pti ? &IDTVEC(int0x80_syscall_pti) : 241 &IDTVEC(int0x80_syscall), SDT_SYSIGT, SEL_UPL, 0); 242 } 243 244 static void 245 ia32_syscall_disable(void *dummy) 246 { 247 248 setidt(IDT_SYSCALL, pti ? &IDTVEC(rsvd_pti) : &IDTVEC(rsvd), 249 SDT_SYSIGT, SEL_KPL, 0); 250 } 251 252 SYSINIT(ia32_syscall, SI_SUB_EXEC, SI_ORDER_ANY, ia32_syscall_enable, NULL); 253 SYSUNINIT(ia32_syscall, SI_SUB_EXEC, SI_ORDER_ANY, ia32_syscall_disable, NULL); 254 255 #ifdef COMPAT_43 256 int 257 setup_lcall_gate(void) 258 { 259 struct i386_ldt_args uap; 260 struct user_segment_descriptor desc; 261 uint32_t lcall_addr; 262 int error; 263 264 bzero(&uap, sizeof(uap)); 265 uap.start = 0; 266 uap.num = 1; 267 lcall_addr = curproc->p_sysent->sv_psstrings - sz_lcall_tramp; 268 bzero(&desc, sizeof(desc)); 269 desc.sd_type = SDT_MEMERA; 270 desc.sd_dpl = SEL_UPL; 271 desc.sd_p = 1; 272 desc.sd_def32 = 1; 273 desc.sd_gran = 1; 274 desc.sd_lolimit = 0xffff; 275 desc.sd_hilimit = 0xf; 276 desc.sd_lobase = lcall_addr; 277 desc.sd_hibase = lcall_addr >> 24; 278 error = amd64_set_ldt(curthread, &uap, &desc); 279 if (error != 0) 280 return (error); 281 282 return (0); 283 } 284 #endif 285