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 /* 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 49 #include <sys/param.h> 50 #include <sys/bus.h> 51 #include <sys/systm.h> 52 #include <sys/proc.h> 53 #include <sys/kernel.h> 54 #include <sys/ktr.h> 55 #include <sys/lock.h> 56 #include <sys/msan.h> 57 #include <sys/mutex.h> 58 #include <sys/proc.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 #include <security/audit/audit.h> 68 69 #include <vm/vm.h> 70 #include <vm/vm_param.h> 71 #include <vm/pmap.h> 72 #include <vm/vm_kern.h> 73 #include <vm/vm_map.h> 74 #include <vm/vm_page.h> 75 #include <vm/vm_extern.h> 76 77 #include <machine/cpu.h> 78 #include <machine/intr_machdep.h> 79 #include <machine/md_var.h> 80 81 #include <compat/freebsd32/freebsd32_signal.h> 82 #include <compat/freebsd32/freebsd32_util.h> 83 #include <compat/ia32/ia32_signal.h> 84 #include <machine/psl.h> 85 #include <machine/segments.h> 86 #include <machine/specialreg.h> 87 #include <machine/sysarch.h> 88 #include <machine/frame.h> 89 #include <machine/md_var.h> 90 #include <machine/pcb.h> 91 #include <machine/cpufunc.h> 92 93 #include "vdso_ia32_offsets.h" 94 95 extern const char _binary_elf_vdso32_so_1_start[]; 96 extern const char _binary_elf_vdso32_so_1_end[]; 97 extern char _binary_elf_vdso32_so_1_size; 98 99 #define IDTVEC(name) __CONCAT(X,name) 100 101 extern inthand_t IDTVEC(int0x80_syscall), IDTVEC(int0x80_syscall_pti), 102 IDTVEC(rsvd), IDTVEC(rsvd_pti); 103 104 void ia32_syscall(struct trapframe *frame); /* Called from asm code */ 105 106 void 107 ia32_set_syscall_retval(struct thread *td, int error) 108 { 109 110 cpu_set_syscall_retval(td, error); 111 } 112 113 int 114 ia32_fetch_syscall_args(struct thread *td) 115 { 116 struct proc *p; 117 struct trapframe *frame; 118 struct syscall_args *sa; 119 caddr_t params; 120 u_int32_t args[8], tmp; 121 int error, i; 122 #ifdef COMPAT_43 123 u_int32_t eip; 124 int cs; 125 #endif 126 127 p = td->td_proc; 128 frame = td->td_frame; 129 sa = &td->td_sa; 130 131 #ifdef COMPAT_43 132 if (__predict_false(frame->tf_cs == 7 && frame->tf_rip == 2)) { 133 /* 134 * In lcall $7,$0 after int $0x80. Convert the user 135 * frame to what it would be for a direct int 0x80 instead 136 * of lcall $7,$0, by popping the lcall return address. 137 */ 138 error = fueword32((void *)frame->tf_rsp, &eip); 139 if (error == -1) 140 return (EFAULT); 141 cs = fuword16((void *)(frame->tf_rsp + sizeof(u_int32_t))); 142 if (cs == -1) 143 return (EFAULT); 144 145 /* 146 * Unwind in-kernel frame after all stack frame pieces 147 * were successfully read. 148 */ 149 frame->tf_rip = eip; 150 frame->tf_cs = cs; 151 frame->tf_rsp += 2 * sizeof(u_int32_t); 152 frame->tf_err = 7; /* size of lcall $7,$0 */ 153 } 154 #endif 155 156 params = (caddr_t)frame->tf_rsp + sizeof(u_int32_t); 157 sa->code = frame->tf_rax; 158 sa->original_code = sa->code; 159 160 /* 161 * Need to check if this is a 32 bit or 64 bit syscall. 162 */ 163 if (sa->code == SYS_syscall) { 164 /* 165 * Code is first argument, followed by actual args. 166 */ 167 error = fueword32(params, &tmp); 168 if (error == -1) 169 return (EFAULT); 170 sa->code = tmp; 171 params += sizeof(int); 172 } else if (sa->code == SYS___syscall) { 173 /* 174 * Like syscall, but code is a quad, so as to maintain 175 * quad alignment for the rest of the arguments. 176 * We use a 32-bit fetch in case params is not 177 * aligned. 178 */ 179 error = fueword32(params, &tmp); 180 if (error == -1) 181 return (EFAULT); 182 sa->code = tmp; 183 params += sizeof(quad_t); 184 } 185 if (sa->code >= p->p_sysent->sv_size) 186 sa->callp = &nosys_sysent; 187 else 188 sa->callp = &p->p_sysent->sv_table[sa->code]; 189 190 if (params != NULL && sa->callp->sy_narg != 0) 191 error = copyin(params, (caddr_t)args, 192 (u_int)(sa->callp->sy_narg * sizeof(int))); 193 else 194 error = 0; 195 196 for (i = 0; i < sa->callp->sy_narg; i++) 197 sa->args[i] = args[i]; 198 199 if (error == 0) { 200 td->td_retval[0] = 0; 201 td->td_retval[1] = frame->tf_rdx; 202 } 203 204 return (error); 205 } 206 207 #include "../../kern/subr_syscall.c" 208 209 void 210 ia32_syscall(struct trapframe *frame) 211 { 212 struct thread *td; 213 register_t orig_tf_rflags; 214 ksiginfo_t ksi; 215 216 kmsan_mark(frame, sizeof(*frame), KMSAN_STATE_INITED); 217 218 orig_tf_rflags = frame->tf_rflags; 219 td = curthread; 220 td->td_frame = frame; 221 222 syscallenter(td); 223 224 /* 225 * Traced syscall. 226 */ 227 if (orig_tf_rflags & PSL_T) { 228 frame->tf_rflags &= ~PSL_T; 229 ksiginfo_init_trap(&ksi); 230 ksi.ksi_signo = SIGTRAP; 231 ksi.ksi_code = TRAP_TRACE; 232 ksi.ksi_addr = (void *)frame->tf_rip; 233 trapsignal(td, &ksi); 234 } 235 236 syscallret(td); 237 amd64_syscall_ret_flush_l1d(td->td_errno); 238 } 239 240 static void 241 ia32_syscall_enable(void *dummy) 242 { 243 244 setidt(IDT_SYSCALL, pti ? &IDTVEC(int0x80_syscall_pti) : 245 &IDTVEC(int0x80_syscall), SDT_SYSIGT, SEL_UPL, 0); 246 } 247 248 static void 249 ia32_syscall_disable(void *dummy) 250 { 251 252 setidt(IDT_SYSCALL, pti ? &IDTVEC(rsvd_pti) : &IDTVEC(rsvd), 253 SDT_SYSIGT, SEL_KPL, 0); 254 } 255 256 SYSINIT(ia32_syscall, SI_SUB_EXEC, SI_ORDER_ANY, ia32_syscall_enable, NULL); 257 SYSUNINIT(ia32_syscall, SI_SUB_EXEC, SI_ORDER_ANY, ia32_syscall_disable, NULL); 258 259 #ifdef COMPAT_43 260 int 261 setup_lcall_gate(void) 262 { 263 struct i386_ldt_args uap; 264 struct user_segment_descriptor desc; 265 uint32_t lcall_addr; 266 int error; 267 268 bzero(&uap, sizeof(uap)); 269 uap.start = 0; 270 uap.num = 1; 271 lcall_addr = PROC_PS_STRINGS(curproc) - 272 (_binary_elf_vdso32_so_1_end - _binary_elf_vdso32_so_1_start) + 273 VDSO_LCALL_TRAMP_OFFSET; 274 bzero(&desc, sizeof(desc)); 275 desc.sd_type = SDT_MEMERA; 276 desc.sd_dpl = SEL_UPL; 277 desc.sd_p = 1; 278 desc.sd_def32 = 1; 279 desc.sd_gran = 1; 280 desc.sd_lolimit = 0xffff; 281 desc.sd_hilimit = 0xf; 282 desc.sd_lobase = lcall_addr; 283 desc.sd_hibase = lcall_addr >> 24; 284 error = amd64_set_ldt(curthread, &uap, &desc); 285 if (error != 0) 286 return (error); 287 288 return (0); 289 } 290 #endif 291