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/ktr.h> 42 #include <sys/lock.h> 43 #include <sys/mutex.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 (sa->code >= p->p_sysent->sv_size) 115 sa->callp = &p->p_sysent->sv_table[0]; 116 else 117 sa->callp = &p->p_sysent->sv_table[sa->code]; 118 119 sa->narg = sa->callp->sy_narg; 120 memcpy(sa->args, ap, nap * sizeof(register_t)); 121 if (sa->narg > nap) 122 panic("TODO: Could we have more then %d args?", NARGREG); 123 124 td->td_retval[0] = 0; 125 td->td_retval[1] = 0; 126 127 return (0); 128 } 129 130 #include "../../kern/subr_syscall.c" 131 132 static void 133 dump_regs(struct trapframe *frame) 134 { 135 int n; 136 int i; 137 138 n = (sizeof(frame->tf_t) / sizeof(frame->tf_t[0])); 139 for (i = 0; i < n; i++) 140 printf("t[%d] == 0x%016lx\n", i, frame->tf_t[i]); 141 142 n = (sizeof(frame->tf_s) / sizeof(frame->tf_s[0])); 143 for (i = 0; i < n; i++) 144 printf("s[%d] == 0x%016lx\n", i, frame->tf_s[i]); 145 146 n = (sizeof(frame->tf_a) / sizeof(frame->tf_a[0])); 147 for (i = 0; i < n; i++) 148 printf("a[%d] == 0x%016lx\n", i, frame->tf_a[i]); 149 150 printf("ra == 0x%016lx\n", frame->tf_ra); 151 printf("sp == 0x%016lx\n", frame->tf_sp); 152 printf("gp == 0x%016lx\n", frame->tf_gp); 153 printf("tp == 0x%016lx\n", frame->tf_tp); 154 155 printf("sepc == 0x%016lx\n", frame->tf_sepc); 156 printf("sstatus == 0x%016lx\n", frame->tf_sstatus); 157 } 158 159 static void 160 svc_handler(struct trapframe *frame) 161 { 162 struct thread *td; 163 164 td = curthread; 165 td->td_frame = frame; 166 167 syscallenter(td); 168 syscallret(td); 169 } 170 171 static void 172 data_abort(struct trapframe *frame, int usermode) 173 { 174 struct vm_map *map; 175 uint64_t stval; 176 struct thread *td; 177 struct pcb *pcb; 178 vm_prot_t ftype; 179 vm_offset_t va; 180 struct proc *p; 181 int error, sig, ucode; 182 183 #ifdef KDB 184 if (kdb_active) { 185 kdb_reenter(); 186 return; 187 } 188 #endif 189 190 td = curthread; 191 p = td->td_proc; 192 pcb = td->td_pcb; 193 stval = frame->tf_stval; 194 195 if (td->td_critnest != 0 || td->td_intr_nesting_level != 0 || 196 WITNESS_CHECK(WARN_SLEEPOK | WARN_GIANTOK, NULL, 197 "Kernel page fault") != 0) 198 goto fatal; 199 200 if (usermode) 201 map = &td->td_proc->p_vmspace->vm_map; 202 else if (stval >= VM_MAX_USER_ADDRESS) 203 map = kernel_map; 204 else { 205 if (pcb->pcb_onfault == 0) 206 goto fatal; 207 map = &td->td_proc->p_vmspace->vm_map; 208 } 209 210 va = trunc_page(stval); 211 212 if ((frame->tf_scause == EXCP_FAULT_STORE) || 213 (frame->tf_scause == EXCP_STORE_PAGE_FAULT)) { 214 ftype = VM_PROT_WRITE; 215 } else if (frame->tf_scause == EXCP_INST_PAGE_FAULT) { 216 ftype = VM_PROT_EXECUTE; 217 } else { 218 ftype = VM_PROT_READ; 219 } 220 221 if (pmap_fault_fixup(map->pmap, va, ftype)) 222 goto done; 223 224 error = vm_fault_trap(map, va, ftype, VM_FAULT_NORMAL, &sig, &ucode); 225 if (error != KERN_SUCCESS) { 226 if (usermode) { 227 call_trapsignal(td, sig, ucode, (void *)stval); 228 } else { 229 if (pcb->pcb_onfault != 0) { 230 frame->tf_a[0] = error; 231 frame->tf_sepc = pcb->pcb_onfault; 232 return; 233 } 234 goto fatal; 235 } 236 } 237 238 done: 239 if (usermode) 240 userret(td, frame); 241 return; 242 243 fatal: 244 dump_regs(frame); 245 panic("Fatal page fault at %#lx: %#016lx", frame->tf_sepc, stval); 246 } 247 248 void 249 do_trap_supervisor(struct trapframe *frame) 250 { 251 uint64_t exception; 252 253 /* Ensure we came from supervisor mode, interrupts disabled */ 254 KASSERT((csr_read(sstatus) & (SSTATUS_SPP | SSTATUS_SIE)) == 255 SSTATUS_SPP, ("Came from S mode with interrupts enabled")); 256 257 exception = (frame->tf_scause & EXCP_MASK); 258 if (frame->tf_scause & EXCP_INTR) { 259 /* Interrupt */ 260 riscv_cpu_intr(frame); 261 return; 262 } 263 264 #ifdef KDTRACE_HOOKS 265 if (dtrace_trap_func != NULL && (*dtrace_trap_func)(frame, exception)) 266 return; 267 #endif 268 269 CTR3(KTR_TRAP, "do_trap_supervisor: curthread: %p, sepc: %lx, frame: %p", 270 curthread, frame->tf_sepc, frame); 271 272 switch(exception) { 273 case EXCP_FAULT_LOAD: 274 case EXCP_FAULT_STORE: 275 case EXCP_FAULT_FETCH: 276 case EXCP_STORE_PAGE_FAULT: 277 case EXCP_LOAD_PAGE_FAULT: 278 data_abort(frame, 0); 279 break; 280 case EXCP_BREAKPOINT: 281 #ifdef KDTRACE_HOOKS 282 if (dtrace_invop_jump_addr != NULL && 283 dtrace_invop_jump_addr(frame) == 0) 284 break; 285 #endif 286 #ifdef KDB 287 kdb_trap(exception, 0, frame); 288 #else 289 dump_regs(frame); 290 panic("No debugger in kernel.\n"); 291 #endif 292 break; 293 case EXCP_ILLEGAL_INSTRUCTION: 294 dump_regs(frame); 295 panic("Illegal instruction at 0x%016lx\n", frame->tf_sepc); 296 break; 297 default: 298 dump_regs(frame); 299 panic("Unknown kernel exception %x trap value %lx\n", 300 exception, frame->tf_stval); 301 } 302 } 303 304 void 305 do_trap_user(struct trapframe *frame) 306 { 307 uint64_t exception; 308 struct thread *td; 309 struct pcb *pcb; 310 311 td = curthread; 312 td->td_frame = frame; 313 pcb = td->td_pcb; 314 315 /* Ensure we came from usermode, interrupts disabled */ 316 KASSERT((csr_read(sstatus) & (SSTATUS_SPP | SSTATUS_SIE)) == 0, 317 ("Came from U mode with interrupts enabled")); 318 319 exception = (frame->tf_scause & EXCP_MASK); 320 if (frame->tf_scause & EXCP_INTR) { 321 /* Interrupt */ 322 riscv_cpu_intr(frame); 323 return; 324 } 325 326 CTR3(KTR_TRAP, "do_trap_user: curthread: %p, sepc: %lx, frame: %p", 327 curthread, frame->tf_sepc, frame); 328 329 switch(exception) { 330 case EXCP_FAULT_LOAD: 331 case EXCP_FAULT_STORE: 332 case EXCP_FAULT_FETCH: 333 case EXCP_STORE_PAGE_FAULT: 334 case EXCP_LOAD_PAGE_FAULT: 335 case EXCP_INST_PAGE_FAULT: 336 data_abort(frame, 1); 337 break; 338 case EXCP_USER_ECALL: 339 frame->tf_sepc += 4; /* Next instruction */ 340 svc_handler(frame); 341 break; 342 case EXCP_ILLEGAL_INSTRUCTION: 343 #ifdef FPE 344 if ((pcb->pcb_fpflags & PCB_FP_STARTED) == 0) { 345 /* 346 * May be a FPE trap. Enable FPE usage 347 * for this thread and try again. 348 */ 349 fpe_state_clear(); 350 frame->tf_sstatus &= ~SSTATUS_FS_MASK; 351 frame->tf_sstatus |= SSTATUS_FS_CLEAN; 352 pcb->pcb_fpflags |= PCB_FP_STARTED; 353 break; 354 } 355 #endif 356 call_trapsignal(td, SIGILL, ILL_ILLTRP, (void *)frame->tf_sepc); 357 userret(td, frame); 358 break; 359 case EXCP_BREAKPOINT: 360 call_trapsignal(td, SIGTRAP, TRAP_BRKPT, (void *)frame->tf_sepc); 361 userret(td, frame); 362 break; 363 default: 364 dump_regs(frame); 365 panic("Unknown userland exception %x, trap value %lx\n", 366 exception, frame->tf_stval); 367 } 368 } 369