trap.c revision 1.43.8.2
1 /* $NetBSD: trap.c,v 1.43.8.2 2007/11/06 19:25:05 joerg 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 <sys/cdefs.h> 70 __KERNEL_RCSID(0, "$NetBSD: trap.c,v 1.43.8.2 2007/11/06 19:25:05 joerg Exp $"); 71 72 #include "opt_altivec.h" 73 #include "opt_ddb.h" 74 #include "opt_kgdb.h" 75 76 #include <sys/param.h> 77 #include <sys/proc.h> 78 #include <sys/reboot.h> 79 #include <sys/syscall.h> 80 #include <sys/systm.h> 81 #include <sys/user.h> 82 #include <sys/pool.h> 83 #include <sys/userret.h> 84 #include <sys/kauth.h> 85 86 #if defined(KGDB) 87 #include <sys/kgdb.h> 88 #endif 89 90 #include <uvm/uvm_extern.h> 91 92 #include <dev/cons.h> 93 94 #include <machine/cpu.h> 95 #include <machine/db_machdep.h> 96 #include <machine/fpu.h> 97 #include <machine/frame.h> 98 #include <machine/pcb.h> 99 #include <machine/psl.h> 100 #include <machine/trap.h> 101 102 #include <powerpc/spr.h> 103 #include <powerpc/ibm4xx/pmap.h> 104 #include <powerpc/ibm4xx/tlb.h> 105 #include <powerpc/fpu/fpu_extern.h> 106 107 /* These definitions should probably be somewhere else XXX */ 108 #define FIRSTARG 3 /* first argument is in reg 3 */ 109 #define NARGREG 8 /* 8 args are in registers */ 110 #define MOREARGS(sp) ((void *)((int)(sp) + 8)) /* more args go here */ 111 112 static int fix_unaligned __P((struct lwp *l, struct trapframe *frame)); 113 114 void trap __P((struct trapframe *)); /* Called from locore / trap_subr */ 115 /* Why are these not defined in a header? */ 116 int badaddr __P((void *, size_t)); 117 int badaddr_read __P((void *, size_t, int *)); 118 int ctx_setup __P((int, int)); 119 120 #ifdef DEBUG 121 #define TDB_ALL 0x1 122 int trapdebug = /* TDB_ALL */ 0; 123 #define DBPRINTF(x, y) if (trapdebug & (x)) printf y 124 #else 125 #define DBPRINTF(x, y) 126 #endif 127 128 void 129 trap(struct trapframe *frame) 130 { 131 struct lwp *l = curlwp; 132 struct proc *p = l ? l->l_proc : NULL; 133 int type = frame->exc; 134 int ftype, rv; 135 ksiginfo_t ksi; 136 137 KASSERT(l == 0 || (l->l_stat == LSONPROC)); 138 139 if (frame->srr1 & PSL_PR) { 140 LWP_CACHE_CREDS(l, p); 141 type |= EXC_USER; 142 } 143 144 ftype = VM_PROT_READ; 145 146 DBPRINTF(TDB_ALL, ("trap(%x) at %lx 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; 153 154 __asm volatile("mfspr %0,0x3f0" : 155 "=r" (rv), "=r" (srr2), "=r" (srr3) :); 156 printf("debug reg is %x srr2 %x srr3 %x\n", rv, srr2, 157 srr3); 158 /* XXX fall through or break here?! */ 159 } 160 /* 161 * DEBUG intr -- probably single-step. 162 */ 163 case EXC_TRC|EXC_USER: 164 frame->srr1 &= ~PSL_SE; 165 KSI_INIT_TRAP(&ksi); 166 ksi.ksi_signo = SIGTRAP; 167 ksi.ksi_trap = EXC_TRC; 168 ksi.ksi_addr = (void *)frame->srr0; 169 KERNEL_LOCK(1, l); 170 trapsignal(l, &ksi); 171 KERNEL_UNLOCK_LAST(l); 172 break; 173 174 /* 175 * If we could not find and install appropriate TLB entry, fall through. 176 */ 177 178 case EXC_DSI: 179 /* FALLTHROUGH */ 180 case EXC_DTMISS: 181 { 182 struct vm_map *map; 183 vaddr_t va; 184 struct faultbuf *fb = NULL; 185 186 KERNEL_LOCK(1, NULL); 187 va = frame->dar; 188 if (frame->tf_xtra[TF_PID] == KERNEL_PID) { 189 map = kernel_map; 190 } else { 191 map = &p->p_vmspace->vm_map; 192 } 193 194 if (frame->tf_xtra[TF_ESR] & (ESR_DST|ESR_DIZ)) 195 ftype = VM_PROT_WRITE; 196 197 DBPRINTF(TDB_ALL, 198 ("trap(EXC_DSI) at %lx %s fault on %p esr %x\n", 199 frame->srr0, 200 (ftype & VM_PROT_WRITE) ? "write" : "read", 201 (void *)va, frame->tf_xtra[TF_ESR])); 202 rv = uvm_fault(map, trunc_page(va), ftype); 203 KERNEL_UNLOCK_ONE(NULL); 204 if (rv == 0) 205 goto done; 206 if ((fb = l->l_addr->u_pcb.pcb_onfault) != NULL) { 207 frame->tf_xtra[TF_PID] = KERNEL_PID; 208 frame->srr0 = fb->fb_pc; 209 frame->srr1 |= PSL_IR; /* Re-enable IMMU */ 210 frame->fixreg[1] = fb->fb_sp; 211 frame->fixreg[2] = fb->fb_r2; 212 frame->fixreg[3] = 1; /* Return TRUE */ 213 frame->cr = fb->fb_cr; 214 memcpy(&frame->fixreg[13], fb->fb_fixreg, 215 sizeof(fb->fb_fixreg)); 216 goto done; 217 } 218 } 219 goto brain_damage; 220 221 case EXC_DSI|EXC_USER: 222 /* FALLTHROUGH */ 223 case EXC_DTMISS|EXC_USER: 224 KERNEL_LOCK(1, l); 225 226 if (frame->tf_xtra[TF_ESR] & (ESR_DST|ESR_DIZ)) 227 ftype = VM_PROT_WRITE; 228 229 DBPRINTF(TDB_ALL, 230 ("trap(EXC_DSI|EXC_USER) at %lx %s fault on %lx %x\n", 231 frame->srr0, (ftype & VM_PROT_WRITE) ? "write" : "read", 232 frame->dar, frame->tf_xtra[TF_ESR])); 233 KASSERT(l == curlwp && (l->l_stat == LSONPROC)); 234 rv = uvm_fault(&p->p_vmspace->vm_map, trunc_page(frame->dar), 235 ftype); 236 if (rv == 0) { 237 KERNEL_UNLOCK_LAST(l); 238 break; 239 } 240 KSI_INIT_TRAP(&ksi); 241 ksi.ksi_signo = SIGSEGV; 242 ksi.ksi_trap = EXC_DSI; 243 ksi.ksi_addr = (void *)frame->dar; 244 if (rv == ENOMEM) { 245 printf("UVM: pid %d (%s) lid %d, uid %d killed: " 246 "out of swap\n", 247 p->p_pid, p->p_comm, l->l_lid, 248 l->l_cred ? 249 kauth_cred_geteuid(l->l_cred) : -1); 250 ksi.ksi_signo = SIGKILL; 251 } 252 trapsignal(l, &ksi); 253 KERNEL_UNLOCK_LAST(l); 254 break; 255 256 case EXC_ITMISS|EXC_USER: 257 case EXC_ISI|EXC_USER: 258 KERNEL_LOCK(1, l); 259 ftype = VM_PROT_EXECUTE; 260 DBPRINTF(TDB_ALL, 261 ("trap(EXC_ISI|EXC_USER) at %lx execute fault tf %p\n", 262 frame->srr0, frame)); 263 rv = uvm_fault(&p->p_vmspace->vm_map, trunc_page(frame->srr0), 264 ftype); 265 if (rv == 0) { 266 KERNEL_UNLOCK_LAST(l); 267 break; 268 } 269 KSI_INIT_TRAP(&ksi); 270 ksi.ksi_signo = SIGSEGV; 271 ksi.ksi_trap = EXC_ISI; 272 ksi.ksi_addr = (void *)frame->srr0; 273 ksi.ksi_code = (rv == EACCES ? SEGV_ACCERR : SEGV_MAPERR); 274 trapsignal(l, &ksi); 275 KERNEL_UNLOCK_LAST(l); 276 break; 277 278 case EXC_AST|EXC_USER: 279 curcpu()->ci_astpending = 0; /* we are about to do it */ 280 uvmexp.softs++; 281 if (l->l_pflag & LP_OWEUPC) { 282 l->l_pflag &= ~LP_OWEUPC; 283 ADDUPROF(l); 284 } 285 /* Check whether we are being preempted. */ 286 if (curcpu()->ci_want_resched) 287 preempt(); 288 break; 289 290 291 case EXC_ALI|EXC_USER: 292 KERNEL_LOCK(1, l); 293 if (fix_unaligned(l, frame) != 0) { 294 KSI_INIT_TRAP(&ksi); 295 ksi.ksi_signo = SIGBUS; 296 ksi.ksi_trap = EXC_ALI; 297 ksi.ksi_addr = (void *)frame->dar; 298 trapsignal(l, &ksi); 299 } else 300 frame->srr0 += 4; 301 KERNEL_UNLOCK_LAST(l); 302 break; 303 304 case EXC_PGM|EXC_USER: 305 /* 306 * Illegal insn: 307 * 308 * let's try to see if it's FPU and can be emulated. 309 */ 310 uvmexp.traps++; 311 if (!(l->l_addr->u_pcb.pcb_flags & PCB_FPU)) { 312 memset(&l->l_addr->u_pcb.pcb_fpu, 0, 313 sizeof l->l_addr->u_pcb.pcb_fpu); 314 l->l_addr->u_pcb.pcb_flags |= PCB_FPU; 315 } 316 317 if ((rv = fpu_emulate(frame, 318 (struct fpreg *)&l->l_addr->u_pcb.pcb_fpu))) { 319 KSI_INIT_TRAP(&ksi); 320 ksi.ksi_signo = rv; 321 ksi.ksi_trap = EXC_PGM; 322 ksi.ksi_addr = (void *)frame->srr0; 323 KERNEL_LOCK(1, l); 324 trapsignal(l, &ksi); 325 KERNEL_UNLOCK_LAST(l); 326 } 327 break; 328 329 case EXC_MCHK: 330 { 331 struct faultbuf *fb; 332 333 if ((fb = l->l_addr->u_pcb.pcb_onfault) != NULL) { 334 frame->tf_xtra[TF_PID] = KERNEL_PID; 335 frame->srr0 = fb->fb_pc; 336 frame->srr1 |= PSL_IR; /* Re-enable IMMU */ 337 frame->fixreg[1] = fb->fb_sp; 338 frame->fixreg[2] = fb->fb_r2; 339 frame->fixreg[3] = 1; /* Return TRUE */ 340 frame->cr = fb->fb_cr; 341 memcpy(&frame->fixreg[13], fb->fb_fixreg, 342 sizeof(fb->fb_fixreg)); 343 goto done; 344 } 345 } 346 goto brain_damage; 347 default: 348 brain_damage: 349 printf("trap type 0x%x at 0x%lx\n", type, frame->srr0); 350 #if defined(DDB) || defined(KGDB) 351 if (kdb_trap(type, frame)) 352 goto done; 353 #endif 354 #ifdef TRAP_PANICWAIT 355 printf("Press a key to panic.\n"); 356 cngetc(); 357 #endif 358 panic("trap"); 359 } 360 361 /* Invoke MI userret code */ 362 mi_userret(l); 363 done: 364 return; 365 } 366 367 int 368 ctx_setup(int ctx, int srr1) 369 { 370 volatile struct pmap *pm; 371 372 /* Update PID if we're returning to user mode. */ 373 if (srr1 & PSL_PR) { 374 pm = curproc->p_vmspace->vm_map.pmap; 375 if (!pm->pm_ctx) { 376 ctx_alloc(__UNVOLATILE(pm)); 377 } 378 ctx = pm->pm_ctx; 379 if (srr1 & PSL_SE) { 380 int dbreg, mask = 0x48000000; 381 /* 382 * Set the Internal Debug and 383 * Instruction Completion bits of 384 * the DBCR0 register. 385 * 386 * XXX this is also used by jtag debuggers... 387 */ 388 __asm volatile("mfspr %0,0x3f2;" 389 "or %0,%0,%1;" 390 "mtspr 0x3f2,%0;" : 391 "=&r" (dbreg) : "r" (mask)); 392 } 393 } 394 else if (!ctx) { 395 ctx = KERNEL_PID; 396 } 397 return (ctx); 398 } 399 400 /* 401 * Used by copyin()/copyout() 402 */ 403 extern vaddr_t vmaprange __P((struct proc *, vaddr_t, vsize_t, int)); 404 extern void vunmaprange __P((vaddr_t, vsize_t)); 405 static int bigcopyin __P((const void *, void *, size_t )); 406 static int bigcopyout __P((const void *, void *, size_t )); 407 408 int 409 copyin(const void *udaddr, void *kaddr, size_t len) 410 { 411 struct pmap *pm = curproc->p_vmspace->vm_map.pmap; 412 int msr, pid, tmp, ctx; 413 struct faultbuf env; 414 415 /* For bigger buffers use the faster copy */ 416 if (len > 256) 417 return (bigcopyin(udaddr, kaddr, len)); 418 419 if (setfault(&env)) { 420 curpcb->pcb_onfault = 0; 421 return EFAULT; 422 } 423 424 if (!(ctx = pm->pm_ctx)) { 425 /* No context -- assign it one */ 426 ctx_alloc(pm); 427 ctx = pm->pm_ctx; 428 } 429 430 __asm volatile("addi %6,%6,1; mtctr %6;" /* Set up counter */ 431 "mfmsr %0;" /* Save MSR */ 432 "li %1,0x20; " 433 "andc %1,%0,%1; mtmsr %1;" /* Disable IMMU */ 434 "mfpid %1;" /* Save old PID */ 435 "sync; isync;" 436 437 "1: bdz 2f;" /* while len */ 438 "mtpid %3; sync;" /* Load user ctx */ 439 "lbz %2,0(%4); addi %4,%4,1;" /* Load byte */ 440 "sync; isync;" 441 "mtpid %1;sync;" 442 "stb %2,0(%5); dcbf 0,%5; addi %5,%5,1;" /* Store kernel byte */ 443 "sync; isync;" 444 "b 1b;" /* repeat */ 445 446 "2: mtpid %1; mtmsr %0;" /* Restore PID and MSR */ 447 "sync; isync;" 448 : "=&r" (msr), "=&r" (pid), "=&r" (tmp) 449 : "r" (ctx), "b" (udaddr), "b" (kaddr), "b" (len)); 450 451 curpcb->pcb_onfault = 0; 452 return 0; 453 } 454 455 static int 456 bigcopyin(const void *udaddr, void *kaddr, size_t len) 457 { 458 const char *up; 459 char *kp = kaddr; 460 struct lwp *l = curlwp; 461 struct proc *p; 462 int error; 463 464 if (!l) { 465 return EFAULT; 466 } 467 468 p = l->l_proc; 469 470 /* 471 * Stolen from physio(): 472 */ 473 uvm_lwp_hold(l); 474 error = uvm_vslock(p->p_vmspace, __UNCONST(udaddr), len, VM_PROT_READ); 475 if (error) { 476 uvm_lwp_rele(l); 477 return EFAULT; 478 } 479 up = (char *)vmaprange(p, (vaddr_t)udaddr, len, VM_PROT_READ); 480 481 memcpy(kp, up, len); 482 vunmaprange((vaddr_t)up, len); 483 uvm_vsunlock(p->p_vmspace, __UNCONST(udaddr), len); 484 uvm_lwp_rele(l); 485 486 return 0; 487 } 488 489 int 490 copyout(const void *kaddr, void *udaddr, size_t len) 491 { 492 struct pmap *pm = curproc->p_vmspace->vm_map.pmap; 493 int msr, pid, tmp, ctx; 494 struct faultbuf env; 495 496 /* For big copies use more efficient routine */ 497 if (len > 256) 498 return (bigcopyout(kaddr, udaddr, len)); 499 500 if (setfault(&env)) { 501 curpcb->pcb_onfault = 0; 502 return EFAULT; 503 } 504 505 if (!(ctx = pm->pm_ctx)) { 506 /* No context -- assign it one */ 507 ctx_alloc(pm); 508 ctx = pm->pm_ctx; 509 } 510 511 __asm volatile("addi %6,%6,1; mtctr %6;" /* Set up counter */ 512 "mfmsr %0;" /* Save MSR */ 513 "li %1,0x20; " 514 "andc %1,%0,%1; mtmsr %1;" /* Disable IMMU */ 515 "mfpid %1;" /* Save old PID */ 516 "sync; isync;" 517 518 "1: bdz 2f;" /* while len */ 519 "mtpid %1;sync;" 520 "lbz %2,0(%5); addi %5,%5,1;" /* Load kernel byte */ 521 "sync; isync;" 522 "mtpid %3; sync;" /* Load user ctx */ 523 "stb %2,0(%4); dcbf 0,%4; addi %4,%4,1;" /* Store user byte */ 524 "sync; isync;" 525 "b 1b;" /* repeat */ 526 527 "2: mtpid %1; mtmsr %0;" /* Restore PID and MSR */ 528 "sync; isync;" 529 : "=&r" (msr), "=&r" (pid), "=&r" (tmp) 530 : "r" (ctx), "b" (udaddr), "b" (kaddr), "b" (len)); 531 532 curpcb->pcb_onfault = 0; 533 return 0; 534 } 535 536 static int 537 bigcopyout(const void *kaddr, void *udaddr, size_t len) 538 { 539 char *up; 540 const char *kp = (const char *)kaddr; 541 struct lwp *l = curlwp; 542 struct proc *p; 543 int error; 544 545 if (!l) { 546 return EFAULT; 547 } 548 549 p = l->l_proc; 550 551 /* 552 * Stolen from physio(): 553 */ 554 uvm_lwp_hold(l); 555 error = uvm_vslock(p->p_vmspace, udaddr, len, VM_PROT_WRITE); 556 if (error) { 557 uvm_lwp_rele(l); 558 return EFAULT; 559 } 560 up = (char *)vmaprange(p, (vaddr_t)udaddr, len, 561 VM_PROT_READ | VM_PROT_WRITE); 562 563 memcpy(up, kp, len); 564 vunmaprange((vaddr_t)up, len); 565 uvm_vsunlock(p->p_vmspace, udaddr, len); 566 uvm_lwp_rele(l); 567 568 return 0; 569 } 570 571 /* 572 * kcopy(const void *src, void *dst, size_t len); 573 * 574 * Copy len bytes from src to dst, aborting if we encounter a fatal 575 * page fault. 576 * 577 * kcopy() _must_ save and restore the old fault handler since it is 578 * called by uiomove(), which may be in the path of servicing a non-fatal 579 * page fault. 580 */ 581 int 582 kcopy(const void *src, void *dst, size_t len) 583 { 584 struct faultbuf env, *oldfault; 585 586 oldfault = curpcb->pcb_onfault; 587 if (setfault(&env)) { 588 curpcb->pcb_onfault = oldfault; 589 return EFAULT; 590 } 591 592 memcpy(dst, src, len); 593 594 curpcb->pcb_onfault = oldfault; 595 return 0; 596 } 597 598 int 599 badaddr(void *addr, size_t size) 600 { 601 602 return badaddr_read(addr, size, NULL); 603 } 604 605 int 606 badaddr_read(void *addr, size_t size, int *rptr) 607 { 608 struct faultbuf env; 609 int x; 610 611 /* Get rid of any stale machine checks that have been waiting. */ 612 __asm volatile ("sync; isync"); 613 614 if (setfault(&env)) { 615 curpcb->pcb_onfault = 0; 616 __asm volatile ("sync"); 617 return 1; 618 } 619 620 __asm volatile ("sync"); 621 622 switch (size) { 623 case 1: 624 x = *(volatile int8_t *)addr; 625 break; 626 case 2: 627 x = *(volatile int16_t *)addr; 628 break; 629 case 4: 630 x = *(volatile int32_t *)addr; 631 break; 632 default: 633 panic("badaddr: invalid size (%d)", size); 634 } 635 636 /* Make sure we took the machine check, if we caused one. */ 637 __asm volatile ("sync; isync"); 638 639 curpcb->pcb_onfault = 0; 640 __asm volatile ("sync"); /* To be sure. */ 641 642 /* Use the value to avoid reorder. */ 643 if (rptr) 644 *rptr = x; 645 646 return 0; 647 } 648 649 /* 650 * For now, this only deals with the particular unaligned access case 651 * that gcc tends to generate. Eventually it should handle all of the 652 * possibilities that can happen on a 32-bit PowerPC in big-endian mode. 653 */ 654 655 static int 656 fix_unaligned(struct lwp *l, struct trapframe *frame) 657 { 658 659 return -1; 660 } 661 662 /* 663 * Start a new LWP 664 */ 665 void 666 startlwp(arg) 667 void *arg; 668 { 669 int err; 670 ucontext_t *uc = arg; 671 struct lwp *l = curlwp; 672 673 err = cpu_setmcontext(l, &uc->uc_mcontext, uc->uc_flags); 674 #if DIAGNOSTIC 675 if (err) { 676 printf("Error %d from cpu_setmcontext.", err); 677 } 678 #endif 679 pool_put(&lwp_uc_pool, uc); 680 681 /* Invoke MI userret code */ 682 mi_userret(l); 683 } 684
Indexes created Tue Sep 30 20:09:53 GMT 2025