1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * linux/arch/parisc/traps.c 4 * 5 * Copyright (C) 1991, 1992 Linus Torvalds 6 * Copyright (C) 1999, 2000 Philipp Rumpf <prumpf@tux.org> 7 */ 8 9 /* 10 * 'Traps.c' handles hardware traps and faults after we have saved some 11 * state in 'asm.s'. 12 */ 13 14 #include <linux/sched.h> 15 #include <linux/sched/debug.h> 16 #include <linux/kernel.h> 17 #include <linux/string.h> 18 #include <linux/errno.h> 19 #include <linux/ptrace.h> 20 #include <linux/timer.h> 21 #include <linux/delay.h> 22 #include <linux/mm.h> 23 #include <linux/module.h> 24 #include <linux/smp.h> 25 #include <linux/spinlock.h> 26 #include <linux/init.h> 27 #include <linux/interrupt.h> 28 #include <linux/console.h> 29 #include <linux/bug.h> 30 #include <linux/ratelimit.h> 31 #include <linux/uaccess.h> 32 #include <linux/kdebug.h> 33 34 #include <asm/assembly.h> 35 #include <asm/io.h> 36 #include <asm/irq.h> 37 #include <asm/traps.h> 38 #include <asm/unaligned.h> 39 #include <linux/atomic.h> 40 #include <asm/smp.h> 41 #include <asm/pdc.h> 42 #include <asm/pdc_chassis.h> 43 #include <asm/unwind.h> 44 #include <asm/tlbflush.h> 45 #include <asm/cacheflush.h> 46 #include <linux/kgdb.h> 47 #include <linux/kprobes.h> 48 49 #include "../math-emu/math-emu.h" /* for handle_fpe() */ 50 51 static void parisc_show_stack(struct task_struct *task, 52 struct pt_regs *regs, const char *loglvl); 53 54 static int printbinary(char *buf, unsigned long x, int nbits) 55 { 56 unsigned long mask = 1UL << (nbits - 1); 57 while (mask != 0) { 58 *buf++ = (mask & x ? '1' : '0'); 59 mask >>= 1; 60 } 61 *buf = '\0'; 62 63 return nbits; 64 } 65 66 #ifdef CONFIG_64BIT 67 #define RFMT "%016lx" 68 #else 69 #define RFMT "%08lx" 70 #endif 71 #define FFMT "%016llx" /* fpregs are 64-bit always */ 72 73 #define PRINTREGS(lvl,r,f,fmt,x) \ 74 printk("%s%s%02d-%02d " fmt " " fmt " " fmt " " fmt "\n", \ 75 lvl, f, (x), (x+3), (r)[(x)+0], (r)[(x)+1], \ 76 (r)[(x)+2], (r)[(x)+3]) 77 78 static void print_gr(const char *level, struct pt_regs *regs) 79 { 80 int i; 81 char buf[64]; 82 83 printk("%s\n", level); 84 printk("%s YZrvWESTHLNXBCVMcbcbcbcbOGFRQPDI\n", level); 85 printbinary(buf, regs->gr[0], 32); 86 printk("%sPSW: %s %s\n", level, buf, print_tainted()); 87 88 for (i = 0; i < 32; i += 4) 89 PRINTREGS(level, regs->gr, "r", RFMT, i); 90 } 91 92 static void print_fr(const char *level, struct pt_regs *regs) 93 { 94 int i; 95 char buf[64]; 96 struct { u32 sw[2]; } s; 97 98 /* FR are 64bit everywhere. Need to use asm to get the content 99 * of fpsr/fper1, and we assume that we won't have a FP Identify 100 * in our way, otherwise we're screwed. 101 * The fldd is used to restore the T-bit if there was one, as the 102 * store clears it anyway. 103 * PA2.0 book says "thou shall not use fstw on FPSR/FPERs" - T-Bone */ 104 asm volatile ("fstd %%fr0,0(%1) \n\t" 105 "fldd 0(%1),%%fr0 \n\t" 106 : "=m" (s) : "r" (&s) : "r0"); 107 108 printk("%s\n", level); 109 printk("%s VZOUICununcqcqcqcqcqcrmunTDVZOUI\n", level); 110 printbinary(buf, s.sw[0], 32); 111 printk("%sFPSR: %s\n", level, buf); 112 printk("%sFPER1: %08x\n", level, s.sw[1]); 113 114 /* here we'll print fr0 again, tho it'll be meaningless */ 115 for (i = 0; i < 32; i += 4) 116 PRINTREGS(level, regs->fr, "fr", FFMT, i); 117 } 118 119 void show_regs(struct pt_regs *regs) 120 { 121 int i, user; 122 const char *level; 123 unsigned long cr30, cr31; 124 125 user = user_mode(regs); 126 level = user ? KERN_DEBUG : KERN_CRIT; 127 128 show_regs_print_info(level); 129 130 print_gr(level, regs); 131 132 for (i = 0; i < 8; i += 4) 133 PRINTREGS(level, regs->sr, "sr", RFMT, i); 134 135 if (user) 136 print_fr(level, regs); 137 138 cr30 = mfctl(30); 139 cr31 = mfctl(31); 140 printk("%s\n", level); 141 printk("%sIASQ: " RFMT " " RFMT " IAOQ: " RFMT " " RFMT "\n", 142 level, regs->iasq[0], regs->iasq[1], regs->iaoq[0], regs->iaoq[1]); 143 printk("%s IIR: %08lx ISR: " RFMT " IOR: " RFMT "\n", 144 level, regs->iir, regs->isr, regs->ior); 145 printk("%s CPU: %8d CR30: " RFMT " CR31: " RFMT "\n", 146 level, current_thread_info()->cpu, cr30, cr31); 147 printk("%s ORIG_R28: " RFMT "\n", level, regs->orig_r28); 148 149 if (user) { 150 printk("%s IAOQ[0]: " RFMT "\n", level, regs->iaoq[0]); 151 printk("%s IAOQ[1]: " RFMT "\n", level, regs->iaoq[1]); 152 printk("%s RP(r2): " RFMT "\n", level, regs->gr[2]); 153 } else { 154 printk("%s IAOQ[0]: %pS\n", level, (void *) regs->iaoq[0]); 155 printk("%s IAOQ[1]: %pS\n", level, (void *) regs->iaoq[1]); 156 printk("%s RP(r2): %pS\n", level, (void *) regs->gr[2]); 157 158 parisc_show_stack(current, regs, KERN_DEFAULT); 159 } 160 } 161 162 static DEFINE_RATELIMIT_STATE(_hppa_rs, 163 DEFAULT_RATELIMIT_INTERVAL, DEFAULT_RATELIMIT_BURST); 164 165 #define parisc_printk_ratelimited(critical, regs, fmt, ...) { \ 166 if ((critical || show_unhandled_signals) && __ratelimit(&_hppa_rs)) { \ 167 printk(fmt, ##__VA_ARGS__); \ 168 show_regs(regs); \ 169 } \ 170 } 171 172 173 static void do_show_stack(struct unwind_frame_info *info, const char *loglvl) 174 { 175 int i = 1; 176 177 printk("%sBacktrace:\n", loglvl); 178 while (i <= MAX_UNWIND_ENTRIES) { 179 if (unwind_once(info) < 0 || info->ip == 0) 180 break; 181 182 if (__kernel_text_address(info->ip)) { 183 printk("%s [<" RFMT ">] %pS\n", 184 loglvl, info->ip, (void *) info->ip); 185 i++; 186 } 187 } 188 printk("%s\n", loglvl); 189 } 190 191 static void parisc_show_stack(struct task_struct *task, 192 struct pt_regs *regs, const char *loglvl) 193 { 194 struct unwind_frame_info info; 195 196 unwind_frame_init_task(&info, task, regs); 197 198 do_show_stack(&info, loglvl); 199 } 200 201 void show_stack(struct task_struct *t, unsigned long *sp, const char *loglvl) 202 { 203 parisc_show_stack(t, NULL, loglvl); 204 } 205 206 int is_valid_bugaddr(unsigned long iaoq) 207 { 208 return 1; 209 } 210 211 void die_if_kernel(char *str, struct pt_regs *regs, long err) 212 { 213 if (user_mode(regs)) { 214 if (err == 0) 215 return; /* STFU */ 216 217 parisc_printk_ratelimited(1, regs, 218 KERN_CRIT "%s (pid %d): %s (code %ld) at " RFMT "\n", 219 current->comm, task_pid_nr(current), str, err, regs->iaoq[0]); 220 221 return; 222 } 223 224 bust_spinlocks(1); 225 226 oops_enter(); 227 228 /* Amuse the user in a SPARC fashion */ 229 if (err) printk(KERN_CRIT 230 " _______________________________ \n" 231 " < Your System ate a SPARC! Gah! >\n" 232 " ------------------------------- \n" 233 " \\ ^__^\n" 234 " (__)\\ )\\/\\\n" 235 " U ||----w |\n" 236 " || ||\n"); 237 238 /* unlock the pdc lock if necessary */ 239 pdc_emergency_unlock(); 240 241 /* maybe the kernel hasn't booted very far yet and hasn't been able 242 * to initialize the serial or STI console. In that case we should 243 * re-enable the pdc console, so that the user will be able to 244 * identify the problem. */ 245 if (!console_drivers) 246 pdc_console_restart(); 247 248 if (err) 249 printk(KERN_CRIT "%s (pid %d): %s (code %ld)\n", 250 current->comm, task_pid_nr(current), str, err); 251 252 /* Wot's wrong wif bein' racy? */ 253 if (current->thread.flags & PARISC_KERNEL_DEATH) { 254 printk(KERN_CRIT "%s() recursion detected.\n", __func__); 255 local_irq_enable(); 256 while (1); 257 } 258 current->thread.flags |= PARISC_KERNEL_DEATH; 259 260 show_regs(regs); 261 dump_stack(); 262 add_taint(TAINT_DIE, LOCKDEP_NOW_UNRELIABLE); 263 264 if (in_interrupt()) 265 panic("Fatal exception in interrupt"); 266 267 if (panic_on_oops) 268 panic("Fatal exception"); 269 270 oops_exit(); 271 do_exit(SIGSEGV); 272 } 273 274 /* gdb uses break 4,8 */ 275 #define GDB_BREAK_INSN 0x10004 276 static void handle_gdb_break(struct pt_regs *regs, int wot) 277 { 278 force_sig_fault(SIGTRAP, wot, 279 (void __user *) (regs->iaoq[0] & ~3)); 280 } 281 282 static void handle_break(struct pt_regs *regs) 283 { 284 unsigned iir = regs->iir; 285 286 if (unlikely(iir == PARISC_BUG_BREAK_INSN && !user_mode(regs))) { 287 /* check if a BUG() or WARN() trapped here. */ 288 enum bug_trap_type tt; 289 tt = report_bug(regs->iaoq[0] & ~3, regs); 290 if (tt == BUG_TRAP_TYPE_WARN) { 291 regs->iaoq[0] += 4; 292 regs->iaoq[1] += 4; 293 return; /* return to next instruction when WARN_ON(). */ 294 } 295 die_if_kernel("Unknown kernel breakpoint", regs, 296 (tt == BUG_TRAP_TYPE_NONE) ? 9 : 0); 297 } 298 299 #ifdef CONFIG_KPROBES 300 if (unlikely(iir == PARISC_KPROBES_BREAK_INSN)) { 301 parisc_kprobe_break_handler(regs); 302 return; 303 } 304 305 #endif 306 307 #ifdef CONFIG_KGDB 308 if (unlikely(iir == PARISC_KGDB_COMPILED_BREAK_INSN || 309 iir == PARISC_KGDB_BREAK_INSN)) { 310 kgdb_handle_exception(9, SIGTRAP, 0, regs); 311 return; 312 } 313 #endif 314 315 if (unlikely(iir != GDB_BREAK_INSN)) 316 parisc_printk_ratelimited(0, regs, 317 KERN_DEBUG "break %d,%d: pid=%d command='%s'\n", 318 iir & 31, (iir>>13) & ((1<<13)-1), 319 task_pid_nr(current), current->comm); 320 321 /* send standard GDB signal */ 322 handle_gdb_break(regs, TRAP_BRKPT); 323 } 324 325 static void default_trap(int code, struct pt_regs *regs) 326 { 327 printk(KERN_ERR "Trap %d on CPU %d\n", code, smp_processor_id()); 328 show_regs(regs); 329 } 330 331 void (*cpu_lpmc) (int code, struct pt_regs *regs) __read_mostly = default_trap; 332 333 334 void transfer_pim_to_trap_frame(struct pt_regs *regs) 335 { 336 register int i; 337 extern unsigned int hpmc_pim_data[]; 338 struct pdc_hpmc_pim_11 *pim_narrow; 339 struct pdc_hpmc_pim_20 *pim_wide; 340 341 if (boot_cpu_data.cpu_type >= pcxu) { 342 343 pim_wide = (struct pdc_hpmc_pim_20 *)hpmc_pim_data; 344 345 /* 346 * Note: The following code will probably generate a 347 * bunch of truncation error warnings from the compiler. 348 * Could be handled with an ifdef, but perhaps there 349 * is a better way. 350 */ 351 352 regs->gr[0] = pim_wide->cr[22]; 353 354 for (i = 1; i < 32; i++) 355 regs->gr[i] = pim_wide->gr[i]; 356 357 for (i = 0; i < 32; i++) 358 regs->fr[i] = pim_wide->fr[i]; 359 360 for (i = 0; i < 8; i++) 361 regs->sr[i] = pim_wide->sr[i]; 362 363 regs->iasq[0] = pim_wide->cr[17]; 364 regs->iasq[1] = pim_wide->iasq_back; 365 regs->iaoq[0] = pim_wide->cr[18]; 366 regs->iaoq[1] = pim_wide->iaoq_back; 367 368 regs->sar = pim_wide->cr[11]; 369 regs->iir = pim_wide->cr[19]; 370 regs->isr = pim_wide->cr[20]; 371 regs->ior = pim_wide->cr[21]; 372 } 373 else { 374 pim_narrow = (struct pdc_hpmc_pim_11 *)hpmc_pim_data; 375 376 regs->gr[0] = pim_narrow->cr[22]; 377 378 for (i = 1; i < 32; i++) 379 regs->gr[i] = pim_narrow->gr[i]; 380 381 for (i = 0; i < 32; i++) 382 regs->fr[i] = pim_narrow->fr[i]; 383 384 for (i = 0; i < 8; i++) 385 regs->sr[i] = pim_narrow->sr[i]; 386 387 regs->iasq[0] = pim_narrow->cr[17]; 388 regs->iasq[1] = pim_narrow->iasq_back; 389 regs->iaoq[0] = pim_narrow->cr[18]; 390 regs->iaoq[1] = pim_narrow->iaoq_back; 391 392 regs->sar = pim_narrow->cr[11]; 393 regs->iir = pim_narrow->cr[19]; 394 regs->isr = pim_narrow->cr[20]; 395 regs->ior = pim_narrow->cr[21]; 396 } 397 398 /* 399 * The following fields only have meaning if we came through 400 * another path. So just zero them here. 401 */ 402 403 regs->ksp = 0; 404 regs->kpc = 0; 405 regs->orig_r28 = 0; 406 } 407 408 409 /* 410 * This routine is called as a last resort when everything else 411 * has gone clearly wrong. We get called for faults in kernel space, 412 * and HPMC's. 413 */ 414 void parisc_terminate(char *msg, struct pt_regs *regs, int code, unsigned long offset) 415 { 416 static DEFINE_SPINLOCK(terminate_lock); 417 418 (void)notify_die(DIE_OOPS, msg, regs, 0, code, SIGTRAP); 419 bust_spinlocks(1); 420 421 set_eiem(0); 422 local_irq_disable(); 423 spin_lock(&terminate_lock); 424 425 /* unlock the pdc lock if necessary */ 426 pdc_emergency_unlock(); 427 428 /* restart pdc console if necessary */ 429 if (!console_drivers) 430 pdc_console_restart(); 431 432 /* Not all paths will gutter the processor... */ 433 switch(code){ 434 435 case 1: 436 transfer_pim_to_trap_frame(regs); 437 break; 438 439 default: 440 break; 441 442 } 443 444 { 445 /* show_stack(NULL, (unsigned long *)regs->gr[30]); */ 446 struct unwind_frame_info info; 447 unwind_frame_init(&info, current, regs); 448 do_show_stack(&info, KERN_CRIT); 449 } 450 451 printk("\n"); 452 pr_crit("%s: Code=%d (%s) at addr " RFMT "\n", 453 msg, code, trap_name(code), offset); 454 show_regs(regs); 455 456 spin_unlock(&terminate_lock); 457 458 /* put soft power button back under hardware control; 459 * if the user had pressed it once at any time, the 460 * system will shut down immediately right here. */ 461 pdc_soft_power_button(0); 462 463 /* Call kernel panic() so reboot timeouts work properly 464 * FIXME: This function should be on the list of 465 * panic notifiers, and we should call panic 466 * directly from the location that we wish. 467 * e.g. We should not call panic from 468 * parisc_terminate, but rather the oter way around. 469 * This hack works, prints the panic message twice, 470 * and it enables reboot timers! 471 */ 472 panic(msg); 473 } 474 475 void notrace handle_interruption(int code, struct pt_regs *regs) 476 { 477 unsigned long fault_address = 0; 478 unsigned long fault_space = 0; 479 int si_code; 480 481 if (code == 1) 482 pdc_console_restart(); /* switch back to pdc if HPMC */ 483 else 484 local_irq_enable(); 485 486 /* Security check: 487 * If the priority level is still user, and the 488 * faulting space is not equal to the active space 489 * then the user is attempting something in a space 490 * that does not belong to them. Kill the process. 491 * 492 * This is normally the situation when the user 493 * attempts to jump into the kernel space at the 494 * wrong offset, be it at the gateway page or a 495 * random location. 496 * 497 * We cannot normally signal the process because it 498 * could *be* on the gateway page, and processes 499 * executing on the gateway page can't have signals 500 * delivered. 501 * 502 * We merely readjust the address into the users 503 * space, at a destination address of zero, and 504 * allow processing to continue. 505 */ 506 if (((unsigned long)regs->iaoq[0] & 3) && 507 ((unsigned long)regs->iasq[0] != (unsigned long)regs->sr[7])) { 508 /* Kill the user process later */ 509 regs->iaoq[0] = 0 | 3; 510 regs->iaoq[1] = regs->iaoq[0] + 4; 511 regs->iasq[0] = regs->iasq[1] = regs->sr[7]; 512 regs->gr[0] &= ~PSW_B; 513 return; 514 } 515 516 #if 0 517 printk(KERN_CRIT "Interruption # %d\n", code); 518 #endif 519 520 switch(code) { 521 522 case 1: 523 /* High-priority machine check (HPMC) */ 524 525 /* set up a new led state on systems shipped with a LED State panel */ 526 pdc_chassis_send_status(PDC_CHASSIS_DIRECT_HPMC); 527 528 parisc_terminate("High Priority Machine Check (HPMC)", 529 regs, code, 0); 530 /* NOT REACHED */ 531 532 case 2: 533 /* Power failure interrupt */ 534 printk(KERN_CRIT "Power failure interrupt !\n"); 535 return; 536 537 case 3: 538 /* Recovery counter trap */ 539 regs->gr[0] &= ~PSW_R; 540 541 #ifdef CONFIG_KPROBES 542 if (parisc_kprobe_ss_handler(regs)) 543 return; 544 #endif 545 546 #ifdef CONFIG_KGDB 547 if (kgdb_single_step) { 548 kgdb_handle_exception(0, SIGTRAP, 0, regs); 549 return; 550 } 551 #endif 552 553 if (user_space(regs)) 554 handle_gdb_break(regs, TRAP_TRACE); 555 /* else this must be the start of a syscall - just let it run */ 556 return; 557 558 case 5: 559 /* Low-priority machine check */ 560 pdc_chassis_send_status(PDC_CHASSIS_DIRECT_LPMC); 561 562 flush_cache_all(); 563 flush_tlb_all(); 564 cpu_lpmc(5, regs); 565 return; 566 567 case PARISC_ITLB_TRAP: 568 /* Instruction TLB miss fault/Instruction page fault */ 569 fault_address = regs->iaoq[0]; 570 fault_space = regs->iasq[0]; 571 break; 572 573 case 8: 574 /* Illegal instruction trap */ 575 die_if_kernel("Illegal instruction", regs, code); 576 si_code = ILL_ILLOPC; 577 goto give_sigill; 578 579 case 9: 580 /* Break instruction trap */ 581 handle_break(regs); 582 return; 583 584 case 10: 585 /* Privileged operation trap */ 586 die_if_kernel("Privileged operation", regs, code); 587 si_code = ILL_PRVOPC; 588 goto give_sigill; 589 590 case 11: 591 /* Privileged register trap */ 592 if ((regs->iir & 0xffdfffe0) == 0x034008a0) { 593 594 /* This is a MFCTL cr26/cr27 to gr instruction. 595 * PCXS traps on this, so we need to emulate it. 596 */ 597 598 if (regs->iir & 0x00200000) 599 regs->gr[regs->iir & 0x1f] = mfctl(27); 600 else 601 regs->gr[regs->iir & 0x1f] = mfctl(26); 602 603 regs->iaoq[0] = regs->iaoq[1]; 604 regs->iaoq[1] += 4; 605 regs->iasq[0] = regs->iasq[1]; 606 return; 607 } 608 609 die_if_kernel("Privileged register usage", regs, code); 610 si_code = ILL_PRVREG; 611 give_sigill: 612 force_sig_fault(SIGILL, si_code, 613 (void __user *) regs->iaoq[0]); 614 return; 615 616 case 12: 617 /* Overflow Trap, let the userland signal handler do the cleanup */ 618 force_sig_fault(SIGFPE, FPE_INTOVF, 619 (void __user *) regs->iaoq[0]); 620 return; 621 622 case 13: 623 /* Conditional Trap 624 The condition succeeds in an instruction which traps 625 on condition */ 626 if(user_mode(regs)){ 627 /* Let userspace app figure it out from the insn pointed 628 * to by si_addr. 629 */ 630 force_sig_fault(SIGFPE, FPE_CONDTRAP, 631 (void __user *) regs->iaoq[0]); 632 return; 633 } 634 /* The kernel doesn't want to handle condition codes */ 635 break; 636 637 case 14: 638 /* Assist Exception Trap, i.e. floating point exception. */ 639 die_if_kernel("Floating point exception", regs, 0); /* quiet */ 640 __inc_irq_stat(irq_fpassist_count); 641 handle_fpe(regs); 642 return; 643 644 case 15: 645 /* Data TLB miss fault/Data page fault */ 646 fallthrough; 647 case 16: 648 /* Non-access instruction TLB miss fault */ 649 /* The instruction TLB entry needed for the target address of the FIC 650 is absent, and hardware can't find it, so we get to cleanup */ 651 fallthrough; 652 case 17: 653 /* Non-access data TLB miss fault/Non-access data page fault */ 654 /* FIXME: 655 Still need to add slow path emulation code here! 656 If the insn used a non-shadow register, then the tlb 657 handlers could not have their side-effect (e.g. probe 658 writing to a target register) emulated since rfir would 659 erase the changes to said register. Instead we have to 660 setup everything, call this function we are in, and emulate 661 by hand. Technically we need to emulate: 662 fdc,fdce,pdc,"fic,4f",prober,probeir,probew, probeiw 663 */ 664 fault_address = regs->ior; 665 fault_space = regs->isr; 666 break; 667 668 case 18: 669 /* PCXS only -- later cpu's split this into types 26,27 & 28 */ 670 /* Check for unaligned access */ 671 if (check_unaligned(regs)) { 672 handle_unaligned(regs); 673 return; 674 } 675 fallthrough; 676 case 26: 677 /* PCXL: Data memory access rights trap */ 678 fault_address = regs->ior; 679 fault_space = regs->isr; 680 break; 681 682 case 19: 683 /* Data memory break trap */ 684 regs->gr[0] |= PSW_X; /* So we can single-step over the trap */ 685 fallthrough; 686 case 21: 687 /* Page reference trap */ 688 handle_gdb_break(regs, TRAP_HWBKPT); 689 return; 690 691 case 25: 692 /* Taken branch trap */ 693 regs->gr[0] &= ~PSW_T; 694 if (user_space(regs)) 695 handle_gdb_break(regs, TRAP_BRANCH); 696 /* else this must be the start of a syscall - just let it 697 * run. 698 */ 699 return; 700 701 case 7: 702 /* Instruction access rights */ 703 /* PCXL: Instruction memory protection trap */ 704 705 /* 706 * This could be caused by either: 1) a process attempting 707 * to execute within a vma that does not have execute 708 * permission, or 2) an access rights violation caused by a 709 * flush only translation set up by ptep_get_and_clear(). 710 * So we check the vma permissions to differentiate the two. 711 * If the vma indicates we have execute permission, then 712 * the cause is the latter one. In this case, we need to 713 * call do_page_fault() to fix the problem. 714 */ 715 716 if (user_mode(regs)) { 717 struct vm_area_struct *vma; 718 719 mmap_read_lock(current->mm); 720 vma = find_vma(current->mm,regs->iaoq[0]); 721 if (vma && (regs->iaoq[0] >= vma->vm_start) 722 && (vma->vm_flags & VM_EXEC)) { 723 724 fault_address = regs->iaoq[0]; 725 fault_space = regs->iasq[0]; 726 727 mmap_read_unlock(current->mm); 728 break; /* call do_page_fault() */ 729 } 730 mmap_read_unlock(current->mm); 731 } 732 fallthrough; 733 case 27: 734 /* Data memory protection ID trap */ 735 if (code == 27 && !user_mode(regs) && 736 fixup_exception(regs)) 737 return; 738 739 die_if_kernel("Protection id trap", regs, code); 740 force_sig_fault(SIGSEGV, SEGV_MAPERR, 741 (code == 7)? 742 ((void __user *) regs->iaoq[0]) : 743 ((void __user *) regs->ior)); 744 return; 745 746 case 28: 747 /* Unaligned data reference trap */ 748 handle_unaligned(regs); 749 return; 750 751 default: 752 if (user_mode(regs)) { 753 parisc_printk_ratelimited(0, regs, KERN_DEBUG 754 "handle_interruption() pid=%d command='%s'\n", 755 task_pid_nr(current), current->comm); 756 /* SIGBUS, for lack of a better one. */ 757 force_sig_fault(SIGBUS, BUS_OBJERR, 758 (void __user *)regs->ior); 759 return; 760 } 761 pdc_chassis_send_status(PDC_CHASSIS_DIRECT_PANIC); 762 763 parisc_terminate("Unexpected interruption", regs, code, 0); 764 /* NOT REACHED */ 765 } 766 767 if (user_mode(regs)) { 768 if ((fault_space >> SPACEID_SHIFT) != (regs->sr[7] >> SPACEID_SHIFT)) { 769 parisc_printk_ratelimited(0, regs, KERN_DEBUG 770 "User fault %d on space 0x%08lx, pid=%d command='%s'\n", 771 code, fault_space, 772 task_pid_nr(current), current->comm); 773 force_sig_fault(SIGSEGV, SEGV_MAPERR, 774 (void __user *)regs->ior); 775 return; 776 } 777 } 778 else { 779 780 /* 781 * The kernel should never fault on its own address space, 782 * unless pagefault_disable() was called before. 783 */ 784 785 if (fault_space == 0 && !faulthandler_disabled()) 786 { 787 /* Clean up and return if in exception table. */ 788 if (fixup_exception(regs)) 789 return; 790 pdc_chassis_send_status(PDC_CHASSIS_DIRECT_PANIC); 791 parisc_terminate("Kernel Fault", regs, code, fault_address); 792 } 793 } 794 795 do_page_fault(regs, code, fault_address); 796 } 797 798 799 void __init initialize_ivt(const void *iva) 800 { 801 extern u32 os_hpmc_size; 802 extern const u32 os_hpmc[]; 803 804 int i; 805 u32 check = 0; 806 u32 *ivap; 807 u32 *hpmcp; 808 u32 length, instr; 809 810 if (strcmp((const char *)iva, "cows can fly")) 811 panic("IVT invalid"); 812 813 ivap = (u32 *)iva; 814 815 for (i = 0; i < 8; i++) 816 *ivap++ = 0; 817 818 /* 819 * Use PDC_INSTR firmware function to get instruction that invokes 820 * PDCE_CHECK in HPMC handler. See programming note at page 1-31 of 821 * the PA 1.1 Firmware Architecture document. 822 */ 823 if (pdc_instr(&instr) == PDC_OK) 824 ivap[0] = instr; 825 826 /* 827 * Rules for the checksum of the HPMC handler: 828 * 1. The IVA does not point to PDC/PDH space (ie: the OS has installed 829 * its own IVA). 830 * 2. The word at IVA + 32 is nonzero. 831 * 3. If Length (IVA + 60) is not zero, then Length (IVA + 60) and 832 * Address (IVA + 56) are word-aligned. 833 * 4. The checksum of the 8 words starting at IVA + 32 plus the sum of 834 * the Length/4 words starting at Address is zero. 835 */ 836 837 /* Setup IVA and compute checksum for HPMC handler */ 838 ivap[6] = (u32)__pa(os_hpmc); 839 length = os_hpmc_size; 840 ivap[7] = length; 841 842 hpmcp = (u32 *)os_hpmc; 843 844 for (i=0; i<length/4; i++) 845 check += *hpmcp++; 846 847 for (i=0; i<8; i++) 848 check += ivap[i]; 849 850 ivap[5] = -check; 851 } 852 853 854 /* early_trap_init() is called before we set up kernel mappings and 855 * write-protect the kernel */ 856 void __init early_trap_init(void) 857 { 858 extern const void fault_vector_20; 859 860 #ifndef CONFIG_64BIT 861 extern const void fault_vector_11; 862 initialize_ivt(&fault_vector_11); 863 #endif 864 865 initialize_ivt(&fault_vector_20); 866 } 867 868 void __init trap_init(void) 869 { 870 } 871