trap.c revision 1.9
1/* $NetBSD: trap.c,v 1.9 2002/11/25 05:11:32 thorpej Exp $ */ 2 3/* 4 * Copyright 2001 Wasabi Systems, Inc. 5 * All rights reserved. 6 * 7 * Written by Eduardo Horvath and Simon Burge for Wasabi Systems, Inc. 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 for the NetBSD Project by 20 * Wasabi Systems, Inc. 21 * 4. The name of Wasabi Systems, Inc. may not be used to endorse 22 * or promote products derived from this software without specific prior 23 * written permission. 24 * 25 * THIS SOFTWARE IS PROVIDED BY WASABI SYSTEMS, INC. ``AS IS'' AND 26 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 27 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 28 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL WASABI SYSTEMS, INC 29 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 30 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 31 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 32 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 33 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 34 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 35 * POSSIBILITY OF SUCH DAMAGE. 36 */ 37 38/* 39 * Copyright (C) 1995, 1996 Wolfgang Solfrank. 40 * Copyright (C) 1995, 1996 TooLs GmbH. 41 * All rights reserved. 42 * 43 * Redistribution and use in source and binary forms, with or without 44 * modification, are permitted provided that the following conditions 45 * are met: 46 * 1. Redistributions of source code must retain the above copyright 47 * notice, this list of conditions and the following disclaimer. 48 * 2. Redistributions in binary form must reproduce the above copyright 49 * notice, this list of conditions and the following disclaimer in the 50 * documentation and/or other materials provided with the distribution. 51 * 3. All advertising materials mentioning features or use of this software 52 * must display the following acknowledgement: 53 * This product includes software developed by TooLs GmbH. 54 * 4. The name of TooLs GmbH may not be used to endorse or promote products 55 * derived from this software without specific prior written permission. 56 * 57 * THIS SOFTWARE IS PROVIDED BY TOOLS GMBH ``AS IS'' AND ANY EXPRESS OR 58 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 59 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 60 * IN NO EVENT SHALL TOOLS GMBH BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 61 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, 62 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; 63 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, 64 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR 65 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF 66 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 67 */ 68 69#include "opt_altivec.h" 70#include "opt_ddb.h" 71#include "opt_ktrace.h" 72#include "opt_systrace.h" 73#include "opt_syscall_debug.h" 74 75#include <sys/param.h> 76#include <sys/proc.h> 77#include <sys/reboot.h> 78#include <sys/syscall.h> 79#include <sys/systm.h> 80#include <sys/user.h> 81#ifdef KTRACE 82#include <sys/ktrace.h> 83#endif 84#ifdef SYSTRACE 85#include <sys/systrace.h> 86#endif 87 88#include <uvm/uvm_extern.h> 89 90#include <dev/cons.h> 91 92#include <machine/cpu.h> 93#include <machine/db_machdep.h> 94#include <machine/fpu.h> 95#include <machine/frame.h> 96#include <machine/pcb.h> 97#include <machine/psl.h> 98#include <machine/trap.h> 99 100#include <powerpc/spr.h> 101#include <powerpc/ibm4xx/pmap.h> 102#include <powerpc/ibm4xx/tlb.h> 103#include <powerpc/fpu/fpu_extern.h> 104 105/* These definitions should probably be somewhere else XXX */ 106#define FIRSTARG 3 /* first argument is in reg 3 */ 107#define NARGREG 8 /* 8 args are in registers */ 108#define MOREARGS(sp) ((caddr_t)((int)(sp) + 8)) /* more args go here */ 109 110#ifndef MULTIPROCESSOR 111volatile int astpending; 112volatile int want_resched; 113#endif 114 115static int fix_unaligned __P((struct proc *p, struct trapframe *frame)); 116 117void trap __P((struct trapframe *)); /* Called from locore / trap_subr */ 118int setfault __P((faultbuf)); /* defined in locore.S */ 119/* Why are these not defined in a header? */ 120int badaddr __P((void *, size_t)); 121int badaddr_read __P((void *, size_t, int *)); 122int ctx_setup __P((int, int)); 123 124#ifdef DEBUG 125#define TDB_ALL 0x1 126int trapdebug = /* TDB_ALL */ 0; 127#define DBPRINTF(x, y) if (trapdebug & (x)) printf y 128#else 129#define DBPRINTF(x, y) 130#endif 131 132void 133trap(struct trapframe *frame) 134{ 135 struct proc *p = curproc; 136 int type = frame->exc; 137 int ftype, rv; 138 139 KASSERT(p == 0 || (p->p_stat == SONPROC)); 140 141 if (frame->srr1 & PSL_PR) 142 type |= EXC_USER; 143 144 ftype = VM_PROT_READ; 145 146DBPRINTF(TDB_ALL, ("trap(%x) at %x from frame %p &frame %p\n", 147 type, frame->srr0, frame, &frame)); 148 149 switch (type) { 150 case EXC_DEBUG|EXC_USER: 151{ 152 int srr2, srr3; 153__asm __volatile("mfspr %0,0x3f0" : "=r" (rv), "=r" (srr2), "=r" (srr3) :); 154printf("debug reg is %x srr2 %x srr3 %x\n", rv, srr2, srr3); 155} 156 /* 157 * DEBUG intr -- probably single-step. 158 */ 159 case EXC_TRC|EXC_USER: 160 KERNEL_PROC_LOCK(p); 161 frame->srr1 &= ~PSL_SE; 162 trapsignal(p, SIGTRAP, EXC_TRC); 163 KERNEL_PROC_UNLOCK(p); 164 break; 165 166 /* If we could not find and install appropriate TLB entry, fall through */ 167 168 case EXC_DSI: 169 /* FALLTHROUGH */ 170 case EXC_DTMISS: 171 { 172 struct vm_map *map; 173 vaddr_t va; 174 faultbuf *fb = NULL; 175 176 KERNEL_LOCK(LK_CANRECURSE|LK_EXCLUSIVE); 177 va = frame->dear; 178 if (frame->pid == KERNEL_PID) { 179 map = kernel_map; 180 } else { 181 map = &p->p_vmspace->vm_map; 182 } 183 184 if (frame->esr & (ESR_DST|ESR_DIZ)) 185 ftype = VM_PROT_WRITE; 186 187DBPRINTF(TDB_ALL, ("trap(EXC_DSI) at %x %s fault on %p esr %x\n", 188frame->srr0, (ftype&VM_PROT_WRITE) ? "write" : "read", (void *)va, frame->esr)); 189 rv = uvm_fault(map, trunc_page(va), 0, ftype); 190 KERNEL_UNLOCK(); 191 if (rv == 0) 192 goto done; 193 if ((fb = p->p_addr->u_pcb.pcb_onfault) != NULL) { 194 frame->pid = KERNEL_PID; 195 frame->srr0 = (*fb)[0]; 196 frame->srr1 |= PSL_IR; /* Re-enable IMMU */ 197 frame->fixreg[1] = (*fb)[1]; 198 frame->fixreg[2] = (*fb)[2]; 199 frame->fixreg[3] = 1; /* Return TRUE */ 200 frame->cr = (*fb)[3]; 201 memcpy(&frame->fixreg[13], &(*fb)[4], 202 19 * sizeof(register_t)); 203 goto done; 204 } 205 } 206 goto brain_damage; 207 208 case EXC_DSI|EXC_USER: 209 /* FALLTHROUGH */ 210 case EXC_DTMISS|EXC_USER: 211 KERNEL_PROC_LOCK(p); 212 213 if (frame->esr & (ESR_DST|ESR_DIZ)) 214 ftype = VM_PROT_WRITE; 215 216DBPRINTF(TDB_ALL, ("trap(EXC_DSI|EXC_USER) at %x %s fault on %x %x\n", 217frame->srr0, (ftype&VM_PROT_WRITE) ? "write" : "read", frame->dear, frame->esr)); 218KASSERT(p == curproc && (p->p_stat == SONPROC)); 219 rv = uvm_fault(&p->p_vmspace->vm_map, 220 trunc_page(frame->dear), 0, ftype); 221 if (rv == 0) { 222 KERNEL_PROC_UNLOCK(p); 223 break; 224 } 225 if (rv == ENOMEM) { 226 printf("UVM: pid %d (%s), uid %d killed: " 227 "out of swap\n", 228 p->p_pid, p->p_comm, 229 p->p_cred && p->p_ucred ? 230 p->p_ucred->cr_uid : -1); 231 trapsignal(p, SIGKILL, EXC_DSI); 232 } else { 233 trapsignal(p, SIGSEGV, EXC_DSI); 234 } 235 KERNEL_PROC_UNLOCK(p); 236 break; 237 case EXC_ITMISS|EXC_USER: 238 case EXC_ISI|EXC_USER: 239 KERNEL_PROC_LOCK(p); 240 ftype = VM_PROT_READ | VM_PROT_EXECUTE; 241DBPRINTF(TDB_ALL, ("trap(EXC_ISI|EXC_USER) at %x %s fault on %x tf %p\n", 242frame->srr0, (ftype&VM_PROT_WRITE) ? "write" : "read", frame->srr0, frame)); 243 rv = uvm_fault(&p->p_vmspace->vm_map, trunc_page(frame->srr0), 0, ftype); 244 if (rv == 0) { 245 KERNEL_PROC_UNLOCK(p); 246 break; 247 } 248 trapsignal(p, SIGSEGV, EXC_ISI); 249 KERNEL_PROC_UNLOCK(p); 250 break; 251 252 case EXC_AST|EXC_USER: 253 astpending = 0; /* we are about to do it */ 254 KERNEL_PROC_LOCK(p); 255 uvmexp.softs++; 256 if (p->p_flag & P_OWEUPC) { 257 p->p_flag &= ~P_OWEUPC; 258 ADDUPROF(p); 259 } 260 /* Check whether we are being preempted. */ 261 if (want_resched) 262 preempt(NULL); 263 KERNEL_PROC_UNLOCK(p); 264 break; 265 266 267 case EXC_ALI|EXC_USER: 268 KERNEL_PROC_LOCK(p); 269 if (fix_unaligned(p, frame) != 0) 270 trapsignal(p, SIGBUS, EXC_ALI); 271 else 272 frame->srr0 += 4; 273 KERNEL_PROC_UNLOCK(p); 274 break; 275 276 case EXC_PGM|EXC_USER: 277 /* 278 * Illegal insn: 279 * 280 * let's try to see if it's FPU and can be emulated. 281 */ 282 uvmexp.traps ++; 283 if (!(p->p_addr->u_pcb.pcb_flags & PCB_FPU)) { 284 memset(&p->p_addr->u_pcb.pcb_fpu, 0, 285 sizeof p->p_addr->u_pcb.pcb_fpu); 286 p->p_addr->u_pcb.pcb_flags |= PCB_FPU; 287 } 288 289 if ((rv = fpu_emulate(frame, 290 (struct fpreg *)&p->p_addr->u_pcb.pcb_fpu))) { 291 KERNEL_PROC_LOCK(p); 292 trapsignal(p, rv, EXC_PGM); 293 KERNEL_PROC_UNLOCK(p); 294 } 295 break; 296 297 case EXC_MCHK: 298 { 299 faultbuf *fb; 300 301 if ((fb = p->p_addr->u_pcb.pcb_onfault) != NULL) { 302 frame->pid = KERNEL_PID; 303 frame->srr0 = (*fb)[0]; 304 frame->srr1 |= PSL_IR; /* Re-enable IMMU */ 305 frame->fixreg[1] = (*fb)[1]; 306 frame->fixreg[2] = (*fb)[2]; 307 frame->fixreg[3] = 1; /* Return TRUE */ 308 frame->cr = (*fb)[3]; 309 memcpy(&frame->fixreg[13], &(*fb)[4], 310 19 * sizeof(register_t)); 311 goto done; 312 } 313 } 314 goto brain_damage; 315 default: 316brain_damage: 317 printf("trap type 0x%x at 0x%x\n", type, frame->srr0); 318#ifdef DDB 319 if (kdb_trap(type, frame)) 320 goto done; 321#endif 322#ifdef TRAP_PANICWAIT 323 printf("Press a key to panic.\n"); 324 cngetc(); 325#endif 326 panic("trap"); 327 } 328 329 /* Take pending signals. */ 330 { 331 int sig; 332 333 while ((sig = CURSIG(p)) != 0) 334 postsig(sig); 335 } 336 337 curcpu()->ci_schedstate.spc_curpriority = p->p_priority = p->p_usrpri; 338 done: 339 return; 340} 341 342int 343ctx_setup(int ctx, int srr1) 344{ 345 volatile struct pmap *pm; 346 347 /* Update PID if we're returning to user mode. */ 348 if (srr1 & PSL_PR) { 349 pm = curproc->p_vmspace->vm_map.pmap; 350 if (!pm->pm_ctx) { 351 ctx_alloc((struct pmap *)pm); 352 } 353 ctx = pm->pm_ctx; 354 if (srr1 & PSL_SE) { 355 int dbreg, mask = 0x48000000; 356 /* 357 * Set the Internal Debug and 358 * Instruction Completion bits of 359 * the DBCR0 register. 360 * 361 * XXX this is also used by jtag debuggers... 362 */ 363 __asm __volatile("mfspr %0,0x3f2;" 364 "or %0,%0,%1;" 365 "mtspr 0x3f2,%0;" : 366 "=&r" (dbreg) : "r" (mask)); 367 } 368 } 369 else if (!ctx) { 370 ctx = KERNEL_PID; 371 } 372 return (ctx); 373} 374 375/* 376 * Used by copyin()/copyout() 377 */ 378extern vaddr_t vmaprange __P((struct proc *, vaddr_t, vsize_t, int)); 379extern void vunmaprange __P((vaddr_t, vsize_t)); 380static int bigcopyin __P((const void *, void *, size_t )); 381static int bigcopyout __P((const void *, void *, size_t )); 382 383int 384copyin(const void *udaddr, void *kaddr, size_t len) 385{ 386 struct pmap *pm = curproc->p_vmspace->vm_map.pmap; 387 int msr, pid, tmp, ctx; 388 faultbuf env; 389 390 /* For bigger buffers use the faster copy */ 391 if (len > 256) return (bigcopyin(udaddr, kaddr, len)); 392 393 if (setfault(env)) { 394 curpcb->pcb_onfault = 0; 395 return EFAULT; 396 } 397 398 if (!(ctx = pm->pm_ctx)) { 399 /* No context -- assign it one */ 400 ctx_alloc(pm); 401 ctx = pm->pm_ctx; 402 } 403 404 asm volatile("addi %6,%6,1; mtctr %6;" /* Set up counter */ 405 "mfmsr %0;" /* Save MSR */ 406 "li %1,0x20; " 407 "andc %1,%0,%1; mtmsr %1;" /* Disable IMMU */ 408 "mfpid %1;" /* Save old PID */ 409 "sync; isync;" 410 411 "1: bdz 2f;" /* while len */ 412 "mtpid %3; sync;" /* Load user ctx */ 413 "lbz %2,0(%4); addi %4,%4,1;" /* Load byte */ 414 "sync; isync;" 415 "mtpid %1;sync;" 416 "stb %2,0(%5); dcbf 0,%5; addi %5,%5,1;" /* Store kernel byte */ 417 "sync; isync;" 418 "b 1b;" /* repeat */ 419 420 "2: mtpid %1; mtmsr %0;" /* Restore PID and MSR */ 421 "sync; isync;" 422 : "=&r" (msr), "=&r" (pid), "=&r" (tmp) 423 : "r" (ctx), "r" (udaddr), "r" (kaddr), "r" (len)); 424 425 curpcb->pcb_onfault = 0; 426 return 0; 427} 428 429static int 430bigcopyin(const void *udaddr, void *kaddr, size_t len) 431{ 432 const char *up; 433 char *kp = kaddr; 434 struct proc *p = curproc; 435 int error; 436 437 if (!p) { 438 return EFAULT; 439 } 440 441 /* 442 * Stolen from physio(): 443 */ 444 PHOLD(p); 445 error = uvm_vslock(p, (caddr_t)udaddr, len, VM_PROT_READ); 446 if (error) { 447 PRELE(p); 448 return EFAULT; 449 } 450 up = (char *)vmaprange(p, (vaddr_t)udaddr, len, VM_PROT_READ); 451 452 memcpy(kp, up, len); 453 vunmaprange((vaddr_t)up, len); 454 uvm_vsunlock(p, (caddr_t)udaddr, len); 455 PRELE(p); 456 457 return 0; 458} 459 460int 461copyout(const void *kaddr, void *udaddr, size_t len) 462{ 463 struct pmap *pm = curproc->p_vmspace->vm_map.pmap; 464 int msr, pid, tmp, ctx; 465 faultbuf env; 466 467 /* For big copies use more efficient routine */ 468 if (len > 256) return (bigcopyout(kaddr, udaddr, len)); 469 470 if (setfault(env)) { 471 curpcb->pcb_onfault = 0; 472 return EFAULT; 473 } 474 475 if (!(ctx = pm->pm_ctx)) { 476 /* No context -- assign it one */ 477 ctx_alloc(pm); 478 ctx = pm->pm_ctx; 479 } 480 481 asm volatile("addi %6,%6,1; mtctr %6;" /* Set up counter */ 482 "mfmsr %0;" /* Save MSR */ 483 "li %1,0x20; " 484 "andc %1,%0,%1; mtmsr %1;" /* Disable IMMU */ 485 "mfpid %1;" /* Save old PID */ 486 "sync; isync;" 487 488 "1: bdz 2f;" /* while len */ 489 "mtpid %1;sync;" 490 "lbz %2,0(%5); addi %5,%5,1;" /* Load kernel byte */ 491 "sync; isync;" 492 "mtpid %3; sync;" /* Load user ctx */ 493 "stb %2,0(%4); dcbf 0,%4; addi %4,%4,1;" /* Store user byte */ 494 "sync; isync;" 495 "b 1b;" /* repeat */ 496 497 "2: mtpid %1; mtmsr %0;" /* Restore PID and MSR */ 498 "sync; isync;" 499 : "=&r" (msr), "=&r" (pid), "=&r" (tmp) 500 : "r" (ctx), "r" (udaddr), "r" (kaddr), "r" (len)); 501 502 curpcb->pcb_onfault = 0; 503 return 0; 504} 505 506static int 507bigcopyout(const void *kaddr, void *udaddr, size_t len) 508{ 509 char *up; 510 const char *kp = (char *)kaddr; 511 struct proc *p = curproc; 512 int error; 513 514 if (!p) { 515 return EFAULT; 516 } 517 518 /* 519 * Stolen from physio(): 520 */ 521 PHOLD(p); 522 error = uvm_vslock(p, udaddr, len, VM_PROT_WRITE); 523 if (error) { 524 PRELE(p); 525 return EFAULT; 526 } 527 up = (char *)vmaprange(p, (vaddr_t)udaddr, len, 528 VM_PROT_READ|VM_PROT_WRITE); 529 530 memcpy(up, kp, len); 531 vunmaprange((vaddr_t)up, len); 532 uvm_vsunlock(p, udaddr, len); 533 PRELE(p); 534 535 return 0; 536} 537 538/* 539 * kcopy(const void *src, void *dst, size_t len); 540 * 541 * Copy len bytes from src to dst, aborting if we encounter a fatal 542 * page fault. 543 * 544 * kcopy() _must_ save and restore the old fault handler since it is 545 * called by uiomove(), which may be in the path of servicing a non-fatal 546 * page fault. 547 */ 548int 549kcopy(const void *src, void *dst, size_t len) 550{ 551 faultbuf env, *oldfault; 552 553 oldfault = curpcb->pcb_onfault; 554 if (setfault(env)) { 555 curpcb->pcb_onfault = oldfault; 556 return EFAULT; 557 } 558 559 memcpy(dst, src, len); 560 561 curpcb->pcb_onfault = oldfault; 562 return 0; 563} 564 565int 566badaddr(void *addr, size_t size) 567{ 568 569 return badaddr_read(addr, size, NULL); 570} 571 572int 573badaddr_read(void *addr, size_t size, int *rptr) 574{ 575 faultbuf env; 576 int x; 577 578 /* Get rid of any stale machine checks that have been waiting. */ 579 __asm __volatile ("sync; isync"); 580 581 if (setfault(env)) { 582 curpcb->pcb_onfault = 0; 583 __asm __volatile ("sync"); 584 return 1; 585 } 586 587 __asm __volatile ("sync"); 588 589 switch (size) { 590 case 1: 591 x = *(volatile int8_t *)addr; 592 break; 593 case 2: 594 x = *(volatile int16_t *)addr; 595 break; 596 case 4: 597 x = *(volatile int32_t *)addr; 598 break; 599 default: 600 panic("badaddr: invalid size (%d)", size); 601 } 602 603 /* Make sure we took the machine check, if we caused one. */ 604 __asm __volatile ("sync; isync"); 605 606 curpcb->pcb_onfault = 0; 607 __asm __volatile ("sync"); /* To be sure. */ 608 609 /* Use the value to avoid reorder. */ 610 if (rptr) 611 *rptr = x; 612 613 return 0; 614} 615 616/* 617 * For now, this only deals with the particular unaligned access case 618 * that gcc tends to generate. Eventually it should handle all of the 619 * possibilities that can happen on a 32-bit PowerPC in big-endian mode. 620 */ 621 622static int 623fix_unaligned(struct proc *p, struct trapframe *frame) 624{ 625 626 return -1; 627} 628