1 /*- 2 * Copyright (c) 2015-2018 Ruslan Bukin <br@bsdpad.com> 3 * All rights reserved. 4 * 5 * Portions of this software were developed by SRI International and the 6 * University of Cambridge Computer Laboratory under DARPA/AFRL contract 7 * FA8750-10-C-0237 ("CTSRD"), as part of the DARPA CRASH research programme. 8 * 9 * Portions of this software were developed by the University of Cambridge 10 * Computer Laboratory as part of the CTSRD Project, with support from the 11 * UK Higher Education Innovation Fund (HEIF). 12 * 13 * Redistribution and use in source and binary forms, with or without 14 * modification, are permitted provided that the following conditions 15 * are met: 16 * 1. Redistributions of source code must retain the above copyright 17 * notice, this list of conditions and the following disclaimer. 18 * 2. Redistributions in binary form must reproduce the above copyright 19 * notice, this list of conditions and the following disclaimer in the 20 * documentation and/or other materials provided with the distribution. 21 * 22 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32 * SUCH DAMAGE. 33 */ 34 35 #include <sys/cdefs.h> 36 __FBSDID("$FreeBSD$"); 37 38 #include <sys/param.h> 39 #include <sys/systm.h> 40 #include <sys/kernel.h> 41 #include <sys/lock.h> 42 #include <sys/mutex.h> 43 #include <sys/pioctl.h> 44 #include <sys/bus.h> 45 #include <sys/proc.h> 46 #include <sys/ptrace.h> 47 #include <sys/syscall.h> 48 #include <sys/sysent.h> 49 #ifdef KDB 50 #include <sys/kdb.h> 51 #endif 52 53 #include <vm/vm.h> 54 #include <vm/pmap.h> 55 #include <vm/vm_kern.h> 56 #include <vm/vm_map.h> 57 #include <vm/vm_param.h> 58 #include <vm/vm_extern.h> 59 60 #ifdef FPE 61 #include <machine/fpe.h> 62 #endif 63 #include <machine/frame.h> 64 #include <machine/pcb.h> 65 #include <machine/pcpu.h> 66 67 #include <machine/resource.h> 68 #include <machine/intr.h> 69 70 #ifdef KDTRACE_HOOKS 71 #include <sys/dtrace_bsd.h> 72 #endif 73 74 int (*dtrace_invop_jump_addr)(struct trapframe *); 75 76 extern register_t fsu_intr_fault; 77 78 /* Called from exception.S */ 79 void do_trap_supervisor(struct trapframe *); 80 void do_trap_user(struct trapframe *); 81 82 static __inline void 83 call_trapsignal(struct thread *td, int sig, int code, void *addr) 84 { 85 ksiginfo_t ksi; 86 87 ksiginfo_init_trap(&ksi); 88 ksi.ksi_signo = sig; 89 ksi.ksi_code = code; 90 ksi.ksi_addr = addr; 91 trapsignal(td, &ksi); 92 } 93 94 int 95 cpu_fetch_syscall_args(struct thread *td) 96 { 97 struct proc *p; 98 register_t *ap; 99 struct syscall_args *sa; 100 int nap; 101 102 nap = NARGREG; 103 p = td->td_proc; 104 sa = &td->td_sa; 105 ap = &td->td_frame->tf_a[0]; 106 107 sa->code = td->td_frame->tf_t[0]; 108 109 if (sa->code == SYS_syscall || sa->code == SYS___syscall) { 110 sa->code = *ap++; 111 nap--; 112 } 113 114 if (p->p_sysent->sv_mask) 115 sa->code &= p->p_sysent->sv_mask; 116 if (sa->code >= p->p_sysent->sv_size) 117 sa->callp = &p->p_sysent->sv_table[0]; 118 else 119 sa->callp = &p->p_sysent->sv_table[sa->code]; 120 121 sa->narg = sa->callp->sy_narg; 122 memcpy(sa->args, ap, nap * sizeof(register_t)); 123 if (sa->narg > nap) 124 panic("TODO: Could we have more then %d args?", NARGREG); 125 126 td->td_retval[0] = 0; 127 td->td_retval[1] = 0; 128 129 return (0); 130 } 131 132 #include "../../kern/subr_syscall.c" 133 134 static void 135 dump_regs(struct trapframe *frame) 136 { 137 int n; 138 int i; 139 140 n = (sizeof(frame->tf_t) / sizeof(frame->tf_t[0])); 141 for (i = 0; i < n; i++) 142 printf("t[%d] == 0x%016lx\n", i, frame->tf_t[i]); 143 144 n = (sizeof(frame->tf_s) / sizeof(frame->tf_s[0])); 145 for (i = 0; i < n; i++) 146 printf("s[%d] == 0x%016lx\n", i, frame->tf_s[i]); 147 148 n = (sizeof(frame->tf_a) / sizeof(frame->tf_a[0])); 149 for (i = 0; i < n; i++) 150 printf("a[%d] == 0x%016lx\n", i, frame->tf_a[i]); 151 152 printf("sepc == 0x%016lx\n", frame->tf_sepc); 153 printf("sstatus == 0x%016lx\n", frame->tf_sstatus); 154 } 155 156 static void 157 svc_handler(struct trapframe *frame) 158 { 159 struct thread *td; 160 int error; 161 162 td = curthread; 163 td->td_frame = frame; 164 165 error = syscallenter(td); 166 syscallret(td, error); 167 } 168 169 static void 170 data_abort(struct trapframe *frame, int lower) 171 { 172 struct vm_map *map; 173 uint64_t sbadaddr; 174 struct thread *td; 175 struct pcb *pcb; 176 vm_prot_t ftype; 177 vm_offset_t va; 178 struct proc *p; 179 int ucode; 180 int error; 181 int sig; 182 183 #ifdef KDB 184 if (kdb_active) { 185 kdb_reenter(); 186 return; 187 } 188 #endif 189 190 td = curthread; 191 pcb = td->td_pcb; 192 sbadaddr = frame->tf_sbadaddr; 193 194 p = td->td_proc; 195 196 if (lower) 197 map = &td->td_proc->p_vmspace->vm_map; 198 else { 199 /* The top bit tells us which range to use */ 200 if ((sbadaddr >> 63) == 1) 201 map = kernel_map; 202 else 203 map = &td->td_proc->p_vmspace->vm_map; 204 } 205 206 va = trunc_page(sbadaddr); 207 208 if ((frame->tf_scause == EXCP_FAULT_STORE) || 209 (frame->tf_scause == EXCP_STORE_PAGE_FAULT)) { 210 ftype = VM_PROT_WRITE; 211 } else if (frame->tf_scause == EXCP_INST_PAGE_FAULT) { 212 ftype = VM_PROT_EXECUTE; 213 } else { 214 ftype = VM_PROT_READ; 215 } 216 217 if (pmap_fault_fixup(map->pmap, va, ftype)) 218 goto done; 219 220 if (map != kernel_map) { 221 /* 222 * Keep swapout from messing with us during this 223 * critical time. 224 */ 225 PROC_LOCK(p); 226 ++p->p_lock; 227 PROC_UNLOCK(p); 228 229 /* Fault in the user page: */ 230 error = vm_fault(map, va, ftype, VM_FAULT_NORMAL); 231 232 PROC_LOCK(p); 233 --p->p_lock; 234 PROC_UNLOCK(p); 235 } else { 236 /* 237 * Don't have to worry about process locking or stacks in the 238 * kernel. 239 */ 240 error = vm_fault(map, va, ftype, VM_FAULT_NORMAL); 241 } 242 243 if (error != KERN_SUCCESS) { 244 if (lower) { 245 sig = SIGSEGV; 246 if (error == KERN_PROTECTION_FAILURE) 247 ucode = SEGV_ACCERR; 248 else 249 ucode = SEGV_MAPERR; 250 call_trapsignal(td, sig, ucode, (void *)sbadaddr); 251 } else { 252 if (td->td_intr_nesting_level == 0 && 253 pcb->pcb_onfault != 0) { 254 frame->tf_a[0] = error; 255 frame->tf_sepc = pcb->pcb_onfault; 256 return; 257 } 258 dump_regs(frame); 259 panic("vm_fault failed: %lx, va 0x%016lx", 260 frame->tf_sepc, sbadaddr); 261 } 262 } 263 264 done: 265 if (lower) 266 userret(td, frame); 267 } 268 269 void 270 do_trap_supervisor(struct trapframe *frame) 271 { 272 uint64_t exception; 273 uint64_t sstatus; 274 275 /* Ensure we came from supervisor mode, interrupts disabled */ 276 __asm __volatile("csrr %0, sstatus" : "=&r" (sstatus)); 277 KASSERT((sstatus & (SSTATUS_SPP | SSTATUS_SIE)) == SSTATUS_SPP, 278 ("We must came from S mode with interrupts disabled")); 279 280 exception = (frame->tf_scause & EXCP_MASK); 281 if (frame->tf_scause & EXCP_INTR) { 282 /* Interrupt */ 283 riscv_cpu_intr(frame); 284 return; 285 } 286 287 #ifdef KDTRACE_HOOKS 288 if (dtrace_trap_func != NULL && (*dtrace_trap_func)(frame, exception)) 289 return; 290 #endif 291 292 CTR3(KTR_TRAP, "do_trap_supervisor: curthread: %p, sepc: %lx, frame: %p", 293 curthread, frame->tf_sepc, frame); 294 295 switch(exception) { 296 case EXCP_FAULT_LOAD: 297 case EXCP_FAULT_STORE: 298 case EXCP_FAULT_FETCH: 299 case EXCP_STORE_PAGE_FAULT: 300 case EXCP_LOAD_PAGE_FAULT: 301 data_abort(frame, 0); 302 break; 303 case EXCP_BREAKPOINT: 304 #ifdef KDTRACE_HOOKS 305 if (dtrace_invop_jump_addr != 0) { 306 dtrace_invop_jump_addr(frame); 307 break; 308 } 309 #endif 310 #ifdef KDB 311 kdb_trap(exception, 0, frame); 312 #else 313 dump_regs(frame); 314 panic("No debugger in kernel.\n"); 315 #endif 316 break; 317 case EXCP_ILLEGAL_INSTRUCTION: 318 dump_regs(frame); 319 panic("Illegal instruction at 0x%016lx\n", frame->tf_sepc); 320 break; 321 default: 322 dump_regs(frame); 323 panic("Unknown kernel exception %x badaddr %lx\n", 324 exception, frame->tf_sbadaddr); 325 } 326 } 327 328 void 329 do_trap_user(struct trapframe *frame) 330 { 331 uint64_t exception; 332 struct thread *td; 333 uint64_t sstatus; 334 struct pcb *pcb; 335 336 td = curthread; 337 td->td_frame = frame; 338 pcb = td->td_pcb; 339 340 /* Ensure we came from usermode, interrupts disabled */ 341 __asm __volatile("csrr %0, sstatus" : "=&r" (sstatus)); 342 KASSERT((sstatus & (SSTATUS_SPP | SSTATUS_SIE)) == 0, 343 ("We must came from U mode with interrupts disabled")); 344 345 exception = (frame->tf_scause & EXCP_MASK); 346 if (frame->tf_scause & EXCP_INTR) { 347 /* Interrupt */ 348 riscv_cpu_intr(frame); 349 return; 350 } 351 352 CTR3(KTR_TRAP, "do_trap_user: curthread: %p, sepc: %lx, frame: %p", 353 curthread, frame->tf_sepc, frame); 354 355 switch(exception) { 356 case EXCP_FAULT_LOAD: 357 case EXCP_FAULT_STORE: 358 case EXCP_FAULT_FETCH: 359 case EXCP_STORE_PAGE_FAULT: 360 case EXCP_LOAD_PAGE_FAULT: 361 case EXCP_INST_PAGE_FAULT: 362 data_abort(frame, 1); 363 break; 364 case EXCP_USER_ECALL: 365 frame->tf_sepc += 4; /* Next instruction */ 366 svc_handler(frame); 367 break; 368 case EXCP_ILLEGAL_INSTRUCTION: 369 #ifdef FPE 370 if ((pcb->pcb_fpflags & PCB_FP_STARTED) == 0) { 371 /* 372 * May be a FPE trap. Enable FPE usage 373 * for this thread and try again. 374 */ 375 fpe_state_clear(); 376 frame->tf_sstatus &= ~SSTATUS_FS_MASK; 377 frame->tf_sstatus |= SSTATUS_FS_CLEAN; 378 pcb->pcb_fpflags |= PCB_FP_STARTED; 379 break; 380 } 381 #endif 382 call_trapsignal(td, SIGILL, ILL_ILLTRP, (void *)frame->tf_sepc); 383 userret(td, frame); 384 break; 385 case EXCP_BREAKPOINT: 386 call_trapsignal(td, SIGTRAP, TRAP_BRKPT, (void *)frame->tf_sepc); 387 userret(td, frame); 388 break; 389 default: 390 dump_regs(frame); 391 panic("Unknown userland exception %x, badaddr %lx\n", 392 exception, frame->tf_sbadaddr); 393 } 394 } 395