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 #include <linux/kfence.h> 34 35 #include <asm/assembly.h> 36 #include <asm/io.h> 37 #include <asm/irq.h> 38 #include <asm/traps.h> 39 #include <asm/unaligned.h> 40 #include <linux/atomic.h> 41 #include <asm/smp.h> 42 #include <asm/pdc.h> 43 #include <asm/pdc_chassis.h> 44 #include <asm/unwind.h> 45 #include <asm/tlbflush.h> 46 #include <asm/cacheflush.h> 47 #include <linux/kgdb.h> 48 #include <linux/kprobes.h> 49 50 #if defined(CONFIG_LIGHTWEIGHT_SPINLOCK_CHECK) 51 #include <asm/spinlock.h> 52 #endif 53 54 #include "../math-emu/math-emu.h" /* for handle_fpe() */ 55 56 static void parisc_show_stack(struct task_struct *task, 57 struct pt_regs *regs, const char *loglvl); 58 59 static int printbinary(char *buf, unsigned long x, int nbits) 60 { 61 unsigned long mask = 1UL << (nbits - 1); 62 while (mask != 0) { 63 *buf++ = (mask & x ? '1' : '0'); 64 mask >>= 1; 65 } 66 *buf = '\0'; 67 68 return nbits; 69 } 70 71 #ifdef CONFIG_64BIT 72 #define RFMT "%016lx" 73 #else 74 #define RFMT "%08lx" 75 #endif 76 #define FFMT "%016llx" /* fpregs are 64-bit always */ 77 78 #define PRINTREGS(lvl,r,f,fmt,x) \ 79 printk("%s%s%02d-%02d " fmt " " fmt " " fmt " " fmt "\n", \ 80 lvl, f, (x), (x+3), (r)[(x)+0], (r)[(x)+1], \ 81 (r)[(x)+2], (r)[(x)+3]) 82 83 static void print_gr(const char *level, struct pt_regs *regs) 84 { 85 int i; 86 char buf[64]; 87 88 printk("%s\n", level); 89 printk("%s YZrvWESTHLNXBCVMcbcbcbcbOGFRQPDI\n", level); 90 printbinary(buf, regs->gr[0], 32); 91 printk("%sPSW: %s %s\n", level, buf, print_tainted()); 92 93 for (i = 0; i < 32; i += 4) 94 PRINTREGS(level, regs->gr, "r", RFMT, i); 95 } 96 97 static void print_fr(const char *level, struct pt_regs *regs) 98 { 99 int i; 100 char buf[64]; 101 struct { u32 sw[2]; } s; 102 103 /* FR are 64bit everywhere. Need to use asm to get the content 104 * of fpsr/fper1, and we assume that we won't have a FP Identify 105 * in our way, otherwise we're screwed. 106 * The fldd is used to restore the T-bit if there was one, as the 107 * store clears it anyway. 108 * PA2.0 book says "thou shall not use fstw on FPSR/FPERs" - T-Bone */ 109 asm volatile ("fstd %%fr0,0(%1) \n\t" 110 "fldd 0(%1),%%fr0 \n\t" 111 : "=m" (s) : "r" (&s) : "r0"); 112 113 printk("%s\n", level); 114 printk("%s VZOUICununcqcqcqcqcqcrmunTDVZOUI\n", level); 115 printbinary(buf, s.sw[0], 32); 116 printk("%sFPSR: %s\n", level, buf); 117 printk("%sFPER1: %08x\n", level, s.sw[1]); 118 119 /* here we'll print fr0 again, tho it'll be meaningless */ 120 for (i = 0; i < 32; i += 4) 121 PRINTREGS(level, regs->fr, "fr", FFMT, i); 122 } 123 124 void show_regs(struct pt_regs *regs) 125 { 126 int i, user; 127 const char *level; 128 unsigned long cr30, cr31; 129 130 user = user_mode(regs); 131 level = user ? KERN_DEBUG : KERN_CRIT; 132 133 show_regs_print_info(level); 134 135 print_gr(level, regs); 136 137 for (i = 0; i < 8; i += 4) 138 PRINTREGS(level, regs->sr, "sr", RFMT, i); 139 140 if (user) 141 print_fr(level, regs); 142 143 cr30 = mfctl(30); 144 cr31 = mfctl(31); 145 printk("%s\n", level); 146 printk("%sIASQ: " RFMT " " RFMT " IAOQ: " RFMT " " RFMT "\n", 147 level, regs->iasq[0], regs->iasq[1], regs->iaoq[0], regs->iaoq[1]); 148 printk("%s IIR: %08lx ISR: " RFMT " IOR: " RFMT "\n", 149 level, regs->iir, regs->isr, regs->ior); 150 printk("%s CPU: %8d CR30: " RFMT " CR31: " RFMT "\n", 151 level, task_cpu(current), cr30, cr31); 152 printk("%s ORIG_R28: " RFMT "\n", level, regs->orig_r28); 153 154 if (user) { 155 printk("%s IAOQ[0]: " RFMT "\n", level, regs->iaoq[0]); 156 printk("%s IAOQ[1]: " RFMT "\n", level, regs->iaoq[1]); 157 printk("%s RP(r2): " RFMT "\n", level, regs->gr[2]); 158 } else { 159 printk("%s IAOQ[0]: %pS\n", level, (void *) regs->iaoq[0]); 160 printk("%s IAOQ[1]: %pS\n", level, (void *) regs->iaoq[1]); 161 printk("%s RP(r2): %pS\n", level, (void *) regs->gr[2]); 162 163 parisc_show_stack(current, regs, KERN_DEFAULT); 164 } 165 } 166 167 static DEFINE_RATELIMIT_STATE(_hppa_rs, 168 DEFAULT_RATELIMIT_INTERVAL, DEFAULT_RATELIMIT_BURST); 169 170 #define parisc_printk_ratelimited(critical, regs, fmt, ...) { \ 171 if ((critical || show_unhandled_signals) && __ratelimit(&_hppa_rs)) { \ 172 printk(fmt, ##__VA_ARGS__); \ 173 show_regs(regs); \ 174 } \ 175 } 176 177 178 static void do_show_stack(struct unwind_frame_info *info, const char *loglvl) 179 { 180 int i = 1; 181 182 printk("%sBacktrace:\n", loglvl); 183 while (i <= MAX_UNWIND_ENTRIES) { 184 if (unwind_once(info) < 0 || info->ip == 0) 185 break; 186 187 if (__kernel_text_address(info->ip)) { 188 printk("%s [<" RFMT ">] %pS\n", 189 loglvl, info->ip, (void *) info->ip); 190 i++; 191 } 192 } 193 printk("%s\n", loglvl); 194 } 195 196 static void parisc_show_stack(struct task_struct *task, 197 struct pt_regs *regs, const char *loglvl) 198 { 199 struct unwind_frame_info info; 200 201 unwind_frame_init_task(&info, task, regs); 202 203 do_show_stack(&info, loglvl); 204 } 205 206 void show_stack(struct task_struct *t, unsigned long *sp, const char *loglvl) 207 { 208 parisc_show_stack(t, NULL, loglvl); 209 } 210 211 int is_valid_bugaddr(unsigned long iaoq) 212 { 213 return 1; 214 } 215 216 void die_if_kernel(char *str, struct pt_regs *regs, long err) 217 { 218 if (user_mode(regs)) { 219 if (err == 0) 220 return; /* STFU */ 221 222 parisc_printk_ratelimited(1, regs, 223 KERN_CRIT "%s (pid %d): %s (code %ld) at " RFMT "\n", 224 current->comm, task_pid_nr(current), str, err, regs->iaoq[0]); 225 226 return; 227 } 228 229 bust_spinlocks(1); 230 231 oops_enter(); 232 233 /* Amuse the user in a SPARC fashion */ 234 if (err) printk(KERN_CRIT 235 " _______________________________ \n" 236 " < Your System ate a SPARC! Gah! >\n" 237 " ------------------------------- \n" 238 " \\ ^__^\n" 239 " (__)\\ )\\/\\\n" 240 " U ||----w |\n" 241 " || ||\n"); 242 243 /* unlock the pdc lock if necessary */ 244 pdc_emergency_unlock(); 245 246 if (err) 247 printk(KERN_CRIT "%s (pid %d): %s (code %ld)\n", 248 current->comm, task_pid_nr(current), str, err); 249 250 /* Wot's wrong wif bein' racy? */ 251 if (current->thread.flags & PARISC_KERNEL_DEATH) { 252 printk(KERN_CRIT "%s() recursion detected.\n", __func__); 253 local_irq_enable(); 254 while (1); 255 } 256 current->thread.flags |= PARISC_KERNEL_DEATH; 257 258 show_regs(regs); 259 dump_stack(); 260 add_taint(TAINT_DIE, LOCKDEP_NOW_UNRELIABLE); 261 262 if (in_interrupt()) 263 panic("Fatal exception in interrupt"); 264 265 if (panic_on_oops) 266 panic("Fatal exception"); 267 268 oops_exit(); 269 make_task_dead(SIGSEGV); 270 } 271 272 /* gdb uses break 4,8 */ 273 #define GDB_BREAK_INSN 0x10004 274 static void handle_gdb_break(struct pt_regs *regs, int wot) 275 { 276 force_sig_fault(SIGTRAP, wot, 277 (void __user *) (regs->iaoq[0] & ~3)); 278 } 279 280 static void handle_break(struct pt_regs *regs) 281 { 282 unsigned iir = regs->iir; 283 284 if (unlikely(iir == PARISC_BUG_BREAK_INSN && !user_mode(regs))) { 285 /* check if a BUG() or WARN() trapped here. */ 286 enum bug_trap_type tt; 287 tt = report_bug(regs->iaoq[0] & ~3, regs); 288 if (tt == BUG_TRAP_TYPE_WARN) { 289 regs->iaoq[0] += 4; 290 regs->iaoq[1] += 4; 291 return; /* return to next instruction when WARN_ON(). */ 292 } 293 die_if_kernel("Unknown kernel breakpoint", regs, 294 (tt == BUG_TRAP_TYPE_NONE) ? 9 : 0); 295 } 296 297 #ifdef CONFIG_KPROBES 298 if (unlikely(iir == PARISC_KPROBES_BREAK_INSN && !user_mode(regs))) { 299 parisc_kprobe_break_handler(regs); 300 return; 301 } 302 if (unlikely(iir == PARISC_KPROBES_BREAK_INSN2 && !user_mode(regs))) { 303 parisc_kprobe_ss_handler(regs); 304 return; 305 } 306 #endif 307 308 #ifdef CONFIG_KGDB 309 if (unlikely((iir == PARISC_KGDB_COMPILED_BREAK_INSN || 310 iir == PARISC_KGDB_BREAK_INSN)) && !user_mode(regs)) { 311 kgdb_handle_exception(9, SIGTRAP, 0, regs); 312 return; 313 } 314 #endif 315 316 #ifdef CONFIG_LIGHTWEIGHT_SPINLOCK_CHECK 317 if ((iir == SPINLOCK_BREAK_INSN) && !user_mode(regs)) { 318 die_if_kernel("Spinlock was trashed", regs, 1); 319 } 320 #endif 321 322 if (unlikely(iir != GDB_BREAK_INSN)) 323 parisc_printk_ratelimited(0, regs, 324 KERN_DEBUG "break %d,%d: pid=%d command='%s'\n", 325 iir & 31, (iir>>13) & ((1<<13)-1), 326 task_pid_nr(current), current->comm); 327 328 /* send standard GDB signal */ 329 handle_gdb_break(regs, TRAP_BRKPT); 330 } 331 332 static void default_trap(int code, struct pt_regs *regs) 333 { 334 printk(KERN_ERR "Trap %d on CPU %d\n", code, smp_processor_id()); 335 show_regs(regs); 336 } 337 338 static void transfer_pim_to_trap_frame(struct pt_regs *regs) 339 { 340 register int i; 341 extern unsigned int hpmc_pim_data[]; 342 struct pdc_hpmc_pim_11 *pim_narrow; 343 struct pdc_hpmc_pim_20 *pim_wide; 344 345 if (boot_cpu_data.cpu_type >= pcxu) { 346 347 pim_wide = (struct pdc_hpmc_pim_20 *)hpmc_pim_data; 348 349 /* 350 * Note: The following code will probably generate a 351 * bunch of truncation error warnings from the compiler. 352 * Could be handled with an ifdef, but perhaps there 353 * is a better way. 354 */ 355 356 regs->gr[0] = pim_wide->cr[22]; 357 358 for (i = 1; i < 32; i++) 359 regs->gr[i] = pim_wide->gr[i]; 360 361 for (i = 0; i < 32; i++) 362 regs->fr[i] = pim_wide->fr[i]; 363 364 for (i = 0; i < 8; i++) 365 regs->sr[i] = pim_wide->sr[i]; 366 367 regs->iasq[0] = pim_wide->cr[17]; 368 regs->iasq[1] = pim_wide->iasq_back; 369 regs->iaoq[0] = pim_wide->cr[18]; 370 regs->iaoq[1] = pim_wide->iaoq_back; 371 372 regs->sar = pim_wide->cr[11]; 373 regs->iir = pim_wide->cr[19]; 374 regs->isr = pim_wide->cr[20]; 375 regs->ior = pim_wide->cr[21]; 376 } 377 else { 378 pim_narrow = (struct pdc_hpmc_pim_11 *)hpmc_pim_data; 379 380 regs->gr[0] = pim_narrow->cr[22]; 381 382 for (i = 1; i < 32; i++) 383 regs->gr[i] = pim_narrow->gr[i]; 384 385 for (i = 0; i < 32; i++) 386 regs->fr[i] = pim_narrow->fr[i]; 387 388 for (i = 0; i < 8; i++) 389 regs->sr[i] = pim_narrow->sr[i]; 390 391 regs->iasq[0] = pim_narrow->cr[17]; 392 regs->iasq[1] = pim_narrow->iasq_back; 393 regs->iaoq[0] = pim_narrow->cr[18]; 394 regs->iaoq[1] = pim_narrow->iaoq_back; 395 396 regs->sar = pim_narrow->cr[11]; 397 regs->iir = pim_narrow->cr[19]; 398 regs->isr = pim_narrow->cr[20]; 399 regs->ior = pim_narrow->cr[21]; 400 } 401 402 /* 403 * The following fields only have meaning if we came through 404 * another path. So just zero them here. 405 */ 406 407 regs->ksp = 0; 408 regs->kpc = 0; 409 regs->orig_r28 = 0; 410 } 411 412 413 /* 414 * This routine is called as a last resort when everything else 415 * has gone clearly wrong. We get called for faults in kernel space, 416 * and HPMC's. 417 */ 418 void parisc_terminate(char *msg, struct pt_regs *regs, int code, unsigned long offset) 419 { 420 static DEFINE_SPINLOCK(terminate_lock); 421 422 (void)notify_die(DIE_OOPS, msg, regs, 0, code, SIGTRAP); 423 bust_spinlocks(1); 424 425 set_eiem(0); 426 local_irq_disable(); 427 spin_lock(&terminate_lock); 428 429 /* unlock the pdc lock if necessary */ 430 pdc_emergency_unlock(); 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 other 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 (!irqs_disabled_flags(regs->gr[0])) 482 local_irq_enable(); 483 484 /* Security check: 485 * If the priority level is still user, and the 486 * faulting space is not equal to the active space 487 * then the user is attempting something in a space 488 * that does not belong to them. Kill the process. 489 * 490 * This is normally the situation when the user 491 * attempts to jump into the kernel space at the 492 * wrong offset, be it at the gateway page or a 493 * random location. 494 * 495 * We cannot normally signal the process because it 496 * could *be* on the gateway page, and processes 497 * executing on the gateway page can't have signals 498 * delivered. 499 * 500 * We merely readjust the address into the users 501 * space, at a destination address of zero, and 502 * allow processing to continue. 503 */ 504 if (((unsigned long)regs->iaoq[0] & 3) && 505 ((unsigned long)regs->iasq[0] != (unsigned long)regs->sr[7])) { 506 /* Kill the user process later */ 507 regs->iaoq[0] = 0 | PRIV_USER; 508 regs->iaoq[1] = regs->iaoq[0] + 4; 509 regs->iasq[0] = regs->iasq[1] = regs->sr[7]; 510 regs->gr[0] &= ~PSW_B; 511 return; 512 } 513 514 #if 0 515 printk(KERN_CRIT "Interruption # %d\n", code); 516 #endif 517 518 switch(code) { 519 520 case 1: 521 /* High-priority machine check (HPMC) */ 522 523 /* set up a new led state on systems shipped with a LED State panel */ 524 pdc_chassis_send_status(PDC_CHASSIS_DIRECT_HPMC); 525 526 parisc_terminate("High Priority Machine Check (HPMC)", 527 regs, code, 0); 528 /* NOT REACHED */ 529 530 case 2: 531 /* Power failure interrupt */ 532 printk(KERN_CRIT "Power failure interrupt !\n"); 533 return; 534 535 case 3: 536 /* Recovery counter trap */ 537 regs->gr[0] &= ~PSW_R; 538 539 #ifdef CONFIG_KGDB 540 if (kgdb_single_step) { 541 kgdb_handle_exception(0, SIGTRAP, 0, regs); 542 return; 543 } 544 #endif 545 546 if (user_space(regs)) 547 handle_gdb_break(regs, TRAP_TRACE); 548 /* else this must be the start of a syscall - just let it run */ 549 return; 550 551 case 5: 552 /* Low-priority machine check */ 553 pdc_chassis_send_status(PDC_CHASSIS_DIRECT_LPMC); 554 555 flush_cache_all(); 556 flush_tlb_all(); 557 default_trap(code, regs); 558 return; 559 560 case PARISC_ITLB_TRAP: 561 /* Instruction TLB miss fault/Instruction page fault */ 562 fault_address = regs->iaoq[0]; 563 fault_space = regs->iasq[0]; 564 break; 565 566 case 8: 567 /* Illegal instruction trap */ 568 die_if_kernel("Illegal instruction", regs, code); 569 si_code = ILL_ILLOPC; 570 goto give_sigill; 571 572 case 9: 573 /* Break instruction trap */ 574 handle_break(regs); 575 return; 576 577 case 10: 578 /* Privileged operation trap */ 579 die_if_kernel("Privileged operation", regs, code); 580 si_code = ILL_PRVOPC; 581 goto give_sigill; 582 583 case 11: 584 /* Privileged register trap */ 585 if ((regs->iir & 0xffdfffe0) == 0x034008a0) { 586 587 /* This is a MFCTL cr26/cr27 to gr instruction. 588 * PCXS traps on this, so we need to emulate it. 589 */ 590 591 if (regs->iir & 0x00200000) 592 regs->gr[regs->iir & 0x1f] = mfctl(27); 593 else 594 regs->gr[regs->iir & 0x1f] = mfctl(26); 595 596 regs->iaoq[0] = regs->iaoq[1]; 597 regs->iaoq[1] += 4; 598 regs->iasq[0] = regs->iasq[1]; 599 return; 600 } 601 602 die_if_kernel("Privileged register usage", regs, code); 603 si_code = ILL_PRVREG; 604 give_sigill: 605 force_sig_fault(SIGILL, si_code, 606 (void __user *) regs->iaoq[0]); 607 return; 608 609 case 12: 610 /* Overflow Trap, let the userland signal handler do the cleanup */ 611 force_sig_fault(SIGFPE, FPE_INTOVF, 612 (void __user *) regs->iaoq[0]); 613 return; 614 615 case 13: 616 /* Conditional Trap 617 The condition succeeds in an instruction which traps 618 on condition */ 619 if(user_mode(regs)){ 620 /* Let userspace app figure it out from the insn pointed 621 * to by si_addr. 622 */ 623 force_sig_fault(SIGFPE, FPE_CONDTRAP, 624 (void __user *) regs->iaoq[0]); 625 return; 626 } 627 /* The kernel doesn't want to handle condition codes */ 628 break; 629 630 case 14: 631 /* Assist Exception Trap, i.e. floating point exception. */ 632 die_if_kernel("Floating point exception", regs, 0); /* quiet */ 633 __inc_irq_stat(irq_fpassist_count); 634 handle_fpe(regs); 635 return; 636 637 case 15: 638 /* Data TLB miss fault/Data page fault */ 639 fallthrough; 640 case 16: 641 /* Non-access instruction TLB miss fault */ 642 /* The instruction TLB entry needed for the target address of the FIC 643 is absent, and hardware can't find it, so we get to cleanup */ 644 fallthrough; 645 case 17: 646 /* Non-access data TLB miss fault/Non-access data page fault */ 647 /* FIXME: 648 Still need to add slow path emulation code here! 649 If the insn used a non-shadow register, then the tlb 650 handlers could not have their side-effect (e.g. probe 651 writing to a target register) emulated since rfir would 652 erase the changes to said register. Instead we have to 653 setup everything, call this function we are in, and emulate 654 by hand. Technically we need to emulate: 655 fdc,fdce,pdc,"fic,4f",prober,probeir,probew, probeiw 656 */ 657 if (code == 17 && handle_nadtlb_fault(regs)) 658 return; 659 fault_address = regs->ior; 660 fault_space = regs->isr; 661 break; 662 663 case 18: 664 /* PCXS only -- later cpu's split this into types 26,27 & 28 */ 665 /* Check for unaligned access */ 666 if (check_unaligned(regs)) { 667 handle_unaligned(regs); 668 return; 669 } 670 fallthrough; 671 case 26: 672 /* PCXL: Data memory access rights trap */ 673 fault_address = regs->ior; 674 fault_space = regs->isr; 675 break; 676 677 case 19: 678 /* Data memory break trap */ 679 regs->gr[0] |= PSW_X; /* So we can single-step over the trap */ 680 fallthrough; 681 case 21: 682 /* Page reference trap */ 683 handle_gdb_break(regs, TRAP_HWBKPT); 684 return; 685 686 case 25: 687 /* Taken branch trap */ 688 regs->gr[0] &= ~PSW_T; 689 if (user_space(regs)) 690 handle_gdb_break(regs, TRAP_BRANCH); 691 /* else this must be the start of a syscall - just let it 692 * run. 693 */ 694 return; 695 696 case 7: 697 /* Instruction access rights */ 698 /* PCXL: Instruction memory protection trap */ 699 700 /* 701 * This could be caused by either: 1) a process attempting 702 * to execute within a vma that does not have execute 703 * permission, or 2) an access rights violation caused by a 704 * flush only translation set up by ptep_get_and_clear(). 705 * So we check the vma permissions to differentiate the two. 706 * If the vma indicates we have execute permission, then 707 * the cause is the latter one. In this case, we need to 708 * call do_page_fault() to fix the problem. 709 */ 710 711 if (user_mode(regs)) { 712 struct vm_area_struct *vma; 713 714 mmap_read_lock(current->mm); 715 vma = find_vma(current->mm,regs->iaoq[0]); 716 if (vma && (regs->iaoq[0] >= vma->vm_start) 717 && (vma->vm_flags & VM_EXEC)) { 718 719 fault_address = regs->iaoq[0]; 720 fault_space = regs->iasq[0]; 721 722 mmap_read_unlock(current->mm); 723 break; /* call do_page_fault() */ 724 } 725 mmap_read_unlock(current->mm); 726 } 727 /* CPU could not fetch instruction, so clear stale IIR value. */ 728 regs->iir = 0xbaadf00d; 729 fallthrough; 730 case 27: 731 /* Data memory protection ID trap */ 732 if (code == 27 && !user_mode(regs) && 733 fixup_exception(regs)) 734 return; 735 736 die_if_kernel("Protection id trap", regs, code); 737 force_sig_fault(SIGSEGV, SEGV_MAPERR, 738 (code == 7)? 739 ((void __user *) regs->iaoq[0]) : 740 ((void __user *) regs->ior)); 741 return; 742 743 case 28: 744 /* Unaligned data reference trap */ 745 handle_unaligned(regs); 746 return; 747 748 default: 749 if (user_mode(regs)) { 750 parisc_printk_ratelimited(0, regs, KERN_DEBUG 751 "handle_interruption() pid=%d command='%s'\n", 752 task_pid_nr(current), current->comm); 753 /* SIGBUS, for lack of a better one. */ 754 force_sig_fault(SIGBUS, BUS_OBJERR, 755 (void __user *)regs->ior); 756 return; 757 } 758 pdc_chassis_send_status(PDC_CHASSIS_DIRECT_PANIC); 759 760 parisc_terminate("Unexpected interruption", regs, code, 0); 761 /* NOT REACHED */ 762 } 763 764 if (user_mode(regs)) { 765 if ((fault_space >> SPACEID_SHIFT) != (regs->sr[7] >> SPACEID_SHIFT)) { 766 parisc_printk_ratelimited(0, regs, KERN_DEBUG 767 "User fault %d on space 0x%08lx, pid=%d command='%s'\n", 768 code, fault_space, 769 task_pid_nr(current), current->comm); 770 force_sig_fault(SIGSEGV, SEGV_MAPERR, 771 (void __user *)regs->ior); 772 return; 773 } 774 } 775 else { 776 777 /* 778 * The kernel should never fault on its own address space, 779 * unless pagefault_disable() was called before. 780 */ 781 782 if (faulthandler_disabled() || fault_space == 0) 783 { 784 /* Clean up and return if in exception table. */ 785 if (fixup_exception(regs)) 786 return; 787 /* Clean up and return if handled by kfence. */ 788 if (kfence_handle_page_fault(fault_address, 789 parisc_acctyp(code, regs->iir) == VM_WRITE, regs)) 790 return; 791 pdc_chassis_send_status(PDC_CHASSIS_DIRECT_PANIC); 792 parisc_terminate("Kernel Fault", regs, code, fault_address); 793 } 794 } 795 796 do_page_fault(regs, code, fault_address); 797 } 798 799 800 static void __init initialize_ivt(const void *iva) 801 { 802 extern const u32 os_hpmc[]; 803 804 int i; 805 u32 check = 0; 806 u32 *ivap; 807 u32 instr; 808 809 if (strcmp((const char *)iva, "cows can fly")) 810 panic("IVT invalid"); 811 812 ivap = (u32 *)iva; 813 814 for (i = 0; i < 8; i++) 815 *ivap++ = 0; 816 817 /* 818 * Use PDC_INSTR firmware function to get instruction that invokes 819 * PDCE_CHECK in HPMC handler. See programming note at page 1-31 of 820 * the PA 1.1 Firmware Architecture document. 821 */ 822 if (pdc_instr(&instr) == PDC_OK) 823 ivap[0] = instr; 824 825 /* 826 * Rules for the checksum of the HPMC handler: 827 * 1. The IVA does not point to PDC/PDH space (ie: the OS has installed 828 * its own IVA). 829 * 2. The word at IVA + 32 is nonzero. 830 * 3. If Length (IVA + 60) is not zero, then Length (IVA + 60) and 831 * Address (IVA + 56) are word-aligned. 832 * 4. The checksum of the 8 words starting at IVA + 32 plus the sum of 833 * the Length/4 words starting at Address is zero. 834 */ 835 836 /* Setup IVA and compute checksum for HPMC handler */ 837 ivap[6] = (u32)__pa(os_hpmc); 838 839 for (i=0; i<8; i++) 840 check += ivap[i]; 841 842 ivap[5] = -check; 843 pr_debug("initialize_ivt: IVA[6] = 0x%08x\n", ivap[6]); 844 } 845 846 847 /* early_trap_init() is called before we set up kernel mappings and 848 * write-protect the kernel */ 849 void __init early_trap_init(void) 850 { 851 extern const void fault_vector_20; 852 853 #ifndef CONFIG_64BIT 854 extern const void fault_vector_11; 855 initialize_ivt(&fault_vector_11); 856 #endif 857 858 initialize_ivt(&fault_vector_20); 859 } 860