1 /* 2 * Architecture-specific trap handling. 3 * 4 * Copyright (C) 1998-2003 Hewlett-Packard Co 5 * David Mosberger-Tang <davidm@hpl.hp.com> 6 * 7 * 05/12/00 grao <goutham.rao@intel.com> : added isr in siginfo for SIGFPE 8 */ 9 10 #include <linux/kernel.h> 11 #include <linux/init.h> 12 #include <linux/sched/signal.h> 13 #include <linux/sched/debug.h> 14 #include <linux/tty.h> 15 #include <linux/vt_kern.h> /* For unblank_screen() */ 16 #include <linux/export.h> 17 #include <linux/extable.h> 18 #include <linux/hardirq.h> 19 #include <linux/kprobes.h> 20 #include <linux/delay.h> /* for ssleep() */ 21 #include <linux/kdebug.h> 22 #include <linux/uaccess.h> 23 24 #include <asm/fpswa.h> 25 #include <asm/intrinsics.h> 26 #include <asm/processor.h> 27 #include <asm/exception.h> 28 #include <asm/setup.h> 29 30 fpswa_interface_t *fpswa_interface; 31 EXPORT_SYMBOL(fpswa_interface); 32 33 void __init 34 trap_init (void) 35 { 36 if (ia64_boot_param->fpswa) 37 /* FPSWA fixup: make the interface pointer a kernel virtual address: */ 38 fpswa_interface = __va(ia64_boot_param->fpswa); 39 } 40 41 int 42 die (const char *str, struct pt_regs *regs, long err) 43 { 44 static struct { 45 spinlock_t lock; 46 u32 lock_owner; 47 int lock_owner_depth; 48 } die = { 49 .lock = __SPIN_LOCK_UNLOCKED(die.lock), 50 .lock_owner = -1, 51 .lock_owner_depth = 0 52 }; 53 static int die_counter; 54 int cpu = get_cpu(); 55 56 if (die.lock_owner != cpu) { 57 console_verbose(); 58 spin_lock_irq(&die.lock); 59 die.lock_owner = cpu; 60 die.lock_owner_depth = 0; 61 bust_spinlocks(1); 62 } 63 put_cpu(); 64 65 if (++die.lock_owner_depth < 3) { 66 printk("%s[%d]: %s %ld [%d]\n", 67 current->comm, task_pid_nr(current), str, err, ++die_counter); 68 if (notify_die(DIE_OOPS, str, regs, err, 255, SIGSEGV) 69 != NOTIFY_STOP) 70 show_regs(regs); 71 else 72 regs = NULL; 73 } else 74 printk(KERN_ERR "Recursive die() failure, output suppressed\n"); 75 76 bust_spinlocks(0); 77 die.lock_owner = -1; 78 add_taint(TAINT_DIE, LOCKDEP_NOW_UNRELIABLE); 79 spin_unlock_irq(&die.lock); 80 81 if (!regs) 82 return 1; 83 84 if (panic_on_oops) 85 panic("Fatal exception"); 86 87 do_exit(SIGSEGV); 88 return 0; 89 } 90 91 int 92 die_if_kernel (char *str, struct pt_regs *regs, long err) 93 { 94 if (!user_mode(regs)) 95 return die(str, regs, err); 96 return 0; 97 } 98 99 void 100 __kprobes ia64_bad_break (unsigned long break_num, struct pt_regs *regs) 101 { 102 siginfo_t siginfo; 103 int sig, code; 104 105 /* SIGILL, SIGFPE, SIGSEGV, and SIGBUS want these field initialized: */ 106 siginfo.si_addr = (void __user *) (regs->cr_iip + ia64_psr(regs)->ri); 107 siginfo.si_imm = break_num; 108 siginfo.si_flags = 0; /* clear __ISR_VALID */ 109 siginfo.si_isr = 0; 110 111 switch (break_num) { 112 case 0: /* unknown error (used by GCC for __builtin_abort()) */ 113 if (notify_die(DIE_BREAK, "break 0", regs, break_num, TRAP_BRKPT, SIGTRAP) 114 == NOTIFY_STOP) 115 return; 116 if (die_if_kernel("bugcheck!", regs, break_num)) 117 return; 118 sig = SIGILL; code = ILL_ILLOPC; 119 break; 120 121 case 1: /* integer divide by zero */ 122 sig = SIGFPE; code = FPE_INTDIV; 123 break; 124 125 case 2: /* integer overflow */ 126 sig = SIGFPE; code = FPE_INTOVF; 127 break; 128 129 case 3: /* range check/bounds check */ 130 sig = SIGFPE; code = FPE_FLTSUB; 131 break; 132 133 case 4: /* null pointer dereference */ 134 sig = SIGSEGV; code = SEGV_MAPERR; 135 break; 136 137 case 5: /* misaligned data */ 138 sig = SIGSEGV; code = BUS_ADRALN; 139 break; 140 141 case 6: /* decimal overflow */ 142 sig = SIGFPE; code = __FPE_DECOVF; 143 break; 144 145 case 7: /* decimal divide by zero */ 146 sig = SIGFPE; code = __FPE_DECDIV; 147 break; 148 149 case 8: /* packed decimal error */ 150 sig = SIGFPE; code = __FPE_DECERR; 151 break; 152 153 case 9: /* invalid ASCII digit */ 154 sig = SIGFPE; code = __FPE_INVASC; 155 break; 156 157 case 10: /* invalid decimal digit */ 158 sig = SIGFPE; code = __FPE_INVDEC; 159 break; 160 161 case 11: /* paragraph stack overflow */ 162 sig = SIGSEGV; code = __SEGV_PSTKOVF; 163 break; 164 165 case 0x3f000 ... 0x3ffff: /* bundle-update in progress */ 166 sig = SIGILL; code = __ILL_BNDMOD; 167 break; 168 169 default: 170 if ((break_num < 0x40000 || break_num > 0x100000) 171 && die_if_kernel("Bad break", regs, break_num)) 172 return; 173 174 if (break_num < 0x80000) { 175 sig = SIGILL; code = __ILL_BREAK; 176 } else { 177 if (notify_die(DIE_BREAK, "bad break", regs, break_num, TRAP_BRKPT, SIGTRAP) 178 == NOTIFY_STOP) 179 return; 180 sig = SIGTRAP; code = TRAP_BRKPT; 181 } 182 } 183 siginfo.si_signo = sig; 184 siginfo.si_errno = 0; 185 siginfo.si_code = code; 186 force_sig_info(sig, &siginfo, current); 187 } 188 189 /* 190 * disabled_fph_fault() is called when a user-level process attempts to access f32..f127 191 * and it doesn't own the fp-high register partition. When this happens, we save the 192 * current fph partition in the task_struct of the fpu-owner (if necessary) and then load 193 * the fp-high partition of the current task (if necessary). Note that the kernel has 194 * access to fph by the time we get here, as the IVT's "Disabled FP-Register" handler takes 195 * care of clearing psr.dfh. 196 */ 197 static inline void 198 disabled_fph_fault (struct pt_regs *regs) 199 { 200 struct ia64_psr *psr = ia64_psr(regs); 201 202 /* first, grant user-level access to fph partition: */ 203 psr->dfh = 0; 204 205 /* 206 * Make sure that no other task gets in on this processor 207 * while we're claiming the FPU 208 */ 209 preempt_disable(); 210 #ifndef CONFIG_SMP 211 { 212 struct task_struct *fpu_owner 213 = (struct task_struct *)ia64_get_kr(IA64_KR_FPU_OWNER); 214 215 if (ia64_is_local_fpu_owner(current)) { 216 preempt_enable_no_resched(); 217 return; 218 } 219 220 if (fpu_owner) 221 ia64_flush_fph(fpu_owner); 222 } 223 #endif /* !CONFIG_SMP */ 224 ia64_set_local_fpu_owner(current); 225 if ((current->thread.flags & IA64_THREAD_FPH_VALID) != 0) { 226 __ia64_load_fpu(current->thread.fph); 227 psr->mfh = 0; 228 } else { 229 __ia64_init_fpu(); 230 /* 231 * Set mfh because the state in thread.fph does not match the state in 232 * the fph partition. 233 */ 234 psr->mfh = 1; 235 } 236 preempt_enable_no_resched(); 237 } 238 239 static inline int 240 fp_emulate (int fp_fault, void *bundle, long *ipsr, long *fpsr, long *isr, long *pr, long *ifs, 241 struct pt_regs *regs) 242 { 243 fp_state_t fp_state; 244 fpswa_ret_t ret; 245 246 if (!fpswa_interface) 247 return -1; 248 249 memset(&fp_state, 0, sizeof(fp_state_t)); 250 251 /* 252 * compute fp_state. only FP registers f6 - f11 are used by the 253 * kernel, so set those bits in the mask and set the low volatile 254 * pointer to point to these registers. 255 */ 256 fp_state.bitmask_low64 = 0xfc0; /* bit6..bit11 */ 257 258 fp_state.fp_state_low_volatile = (fp_state_low_volatile_t *) ®s->f6; 259 /* 260 * unsigned long (*EFI_FPSWA) ( 261 * unsigned long trap_type, 262 * void *Bundle, 263 * unsigned long *pipsr, 264 * unsigned long *pfsr, 265 * unsigned long *pisr, 266 * unsigned long *ppreds, 267 * unsigned long *pifs, 268 * void *fp_state); 269 */ 270 ret = (*fpswa_interface->fpswa)((unsigned long) fp_fault, bundle, 271 (unsigned long *) ipsr, (unsigned long *) fpsr, 272 (unsigned long *) isr, (unsigned long *) pr, 273 (unsigned long *) ifs, &fp_state); 274 275 return ret.status; 276 } 277 278 struct fpu_swa_msg { 279 unsigned long count; 280 unsigned long time; 281 }; 282 static DEFINE_PER_CPU(struct fpu_swa_msg, cpulast); 283 DECLARE_PER_CPU(struct fpu_swa_msg, cpulast); 284 static struct fpu_swa_msg last __cacheline_aligned; 285 286 287 /* 288 * Handle floating-point assist faults and traps. 289 */ 290 static int 291 handle_fpu_swa (int fp_fault, struct pt_regs *regs, unsigned long isr) 292 { 293 long exception, bundle[2]; 294 unsigned long fault_ip; 295 struct siginfo siginfo; 296 297 fault_ip = regs->cr_iip; 298 if (!fp_fault && (ia64_psr(regs)->ri == 0)) 299 fault_ip -= 16; 300 if (copy_from_user(bundle, (void __user *) fault_ip, sizeof(bundle))) 301 return -1; 302 303 if (!(current->thread.flags & IA64_THREAD_FPEMU_NOPRINT)) { 304 unsigned long count, current_jiffies = jiffies; 305 struct fpu_swa_msg *cp = this_cpu_ptr(&cpulast); 306 307 if (unlikely(current_jiffies > cp->time)) 308 cp->count = 0; 309 if (unlikely(cp->count < 5)) { 310 cp->count++; 311 cp->time = current_jiffies + 5 * HZ; 312 313 /* minimize races by grabbing a copy of count BEFORE checking last.time. */ 314 count = last.count; 315 barrier(); 316 317 /* 318 * Lower 4 bits are used as a count. Upper bits are a sequence 319 * number that is updated when count is reset. The cmpxchg will 320 * fail is seqno has changed. This minimizes mutiple cpus 321 * resetting the count. 322 */ 323 if (current_jiffies > last.time) 324 (void) cmpxchg_acq(&last.count, count, 16 + (count & ~15)); 325 326 /* used fetchadd to atomically update the count */ 327 if ((last.count & 15) < 5 && (ia64_fetchadd(1, &last.count, acq) & 15) < 5) { 328 last.time = current_jiffies + 5 * HZ; 329 printk(KERN_WARNING 330 "%s(%d): floating-point assist fault at ip %016lx, isr %016lx\n", 331 current->comm, task_pid_nr(current), regs->cr_iip + ia64_psr(regs)->ri, isr); 332 } 333 } 334 } 335 336 exception = fp_emulate(fp_fault, bundle, ®s->cr_ipsr, ®s->ar_fpsr, &isr, ®s->pr, 337 ®s->cr_ifs, regs); 338 if (fp_fault) { 339 if (exception == 0) { 340 /* emulation was successful */ 341 ia64_increment_ip(regs); 342 } else if (exception == -1) { 343 printk(KERN_ERR "handle_fpu_swa: fp_emulate() returned -1\n"); 344 return -1; 345 } else { 346 /* is next instruction a trap? */ 347 if (exception & 2) { 348 ia64_increment_ip(regs); 349 } 350 siginfo.si_signo = SIGFPE; 351 siginfo.si_errno = 0; 352 siginfo.si_code = FPE_FIXME; /* default code */ 353 siginfo.si_addr = (void __user *) (regs->cr_iip + ia64_psr(regs)->ri); 354 if (isr & 0x11) { 355 siginfo.si_code = FPE_FLTINV; 356 } else if (isr & 0x22) { 357 /* denormal operand gets the same si_code as underflow 358 * see arch/i386/kernel/traps.c:math_error() */ 359 siginfo.si_code = FPE_FLTUND; 360 } else if (isr & 0x44) { 361 siginfo.si_code = FPE_FLTDIV; 362 } 363 siginfo.si_isr = isr; 364 siginfo.si_flags = __ISR_VALID; 365 siginfo.si_imm = 0; 366 force_sig_info(SIGFPE, &siginfo, current); 367 } 368 } else { 369 if (exception == -1) { 370 printk(KERN_ERR "handle_fpu_swa: fp_emulate() returned -1\n"); 371 return -1; 372 } else if (exception != 0) { 373 /* raise exception */ 374 siginfo.si_signo = SIGFPE; 375 siginfo.si_errno = 0; 376 siginfo.si_code = FPE_FIXME; /* default code */ 377 siginfo.si_addr = (void __user *) (regs->cr_iip + ia64_psr(regs)->ri); 378 if (isr & 0x880) { 379 siginfo.si_code = FPE_FLTOVF; 380 } else if (isr & 0x1100) { 381 siginfo.si_code = FPE_FLTUND; 382 } else if (isr & 0x2200) { 383 siginfo.si_code = FPE_FLTRES; 384 } 385 siginfo.si_isr = isr; 386 siginfo.si_flags = __ISR_VALID; 387 siginfo.si_imm = 0; 388 force_sig_info(SIGFPE, &siginfo, current); 389 } 390 } 391 return 0; 392 } 393 394 struct illegal_op_return { 395 unsigned long fkt, arg1, arg2, arg3; 396 }; 397 398 struct illegal_op_return 399 ia64_illegal_op_fault (unsigned long ec, long arg1, long arg2, long arg3, 400 long arg4, long arg5, long arg6, long arg7, 401 struct pt_regs regs) 402 { 403 struct illegal_op_return rv; 404 struct siginfo si; 405 char buf[128]; 406 407 #ifdef CONFIG_IA64_BRL_EMU 408 { 409 extern struct illegal_op_return ia64_emulate_brl (struct pt_regs *, unsigned long); 410 411 rv = ia64_emulate_brl(®s, ec); 412 if (rv.fkt != (unsigned long) -1) 413 return rv; 414 } 415 #endif 416 417 sprintf(buf, "IA-64 Illegal operation fault"); 418 rv.fkt = 0; 419 if (die_if_kernel(buf, ®s, 0)) 420 return rv; 421 422 memset(&si, 0, sizeof(si)); 423 si.si_signo = SIGILL; 424 si.si_code = ILL_ILLOPC; 425 si.si_addr = (void __user *) (regs.cr_iip + ia64_psr(®s)->ri); 426 force_sig_info(SIGILL, &si, current); 427 return rv; 428 } 429 430 void __kprobes 431 ia64_fault (unsigned long vector, unsigned long isr, unsigned long ifa, 432 unsigned long iim, unsigned long itir, long arg5, long arg6, 433 long arg7, struct pt_regs regs) 434 { 435 unsigned long code, error = isr, iip; 436 struct siginfo siginfo; 437 char buf[128]; 438 int result, sig; 439 static const char *reason[] = { 440 "IA-64 Illegal Operation fault", 441 "IA-64 Privileged Operation fault", 442 "IA-64 Privileged Register fault", 443 "IA-64 Reserved Register/Field fault", 444 "Disabled Instruction Set Transition fault", 445 "Unknown fault 5", "Unknown fault 6", "Unknown fault 7", "Illegal Hazard fault", 446 "Unknown fault 9", "Unknown fault 10", "Unknown fault 11", "Unknown fault 12", 447 "Unknown fault 13", "Unknown fault 14", "Unknown fault 15" 448 }; 449 450 if ((isr & IA64_ISR_NA) && ((isr & IA64_ISR_CODE_MASK) == IA64_ISR_CODE_LFETCH)) { 451 /* 452 * This fault was due to lfetch.fault, set "ed" bit in the psr to cancel 453 * the lfetch. 454 */ 455 ia64_psr(®s)->ed = 1; 456 return; 457 } 458 459 iip = regs.cr_iip + ia64_psr(®s)->ri; 460 461 switch (vector) { 462 case 24: /* General Exception */ 463 code = (isr >> 4) & 0xf; 464 sprintf(buf, "General Exception: %s%s", reason[code], 465 (code == 3) ? ((isr & (1UL << 37)) 466 ? " (RSE access)" : " (data access)") : ""); 467 if (code == 8) { 468 # ifdef CONFIG_IA64_PRINT_HAZARDS 469 printk("%s[%d]: possible hazard @ ip=%016lx (pr = %016lx)\n", 470 current->comm, task_pid_nr(current), 471 regs.cr_iip + ia64_psr(®s)->ri, regs.pr); 472 # endif 473 return; 474 } 475 break; 476 477 case 25: /* Disabled FP-Register */ 478 if (isr & 2) { 479 disabled_fph_fault(®s); 480 return; 481 } 482 sprintf(buf, "Disabled FPL fault---not supposed to happen!"); 483 break; 484 485 case 26: /* NaT Consumption */ 486 if (user_mode(®s)) { 487 void __user *addr; 488 489 if (((isr >> 4) & 0xf) == 2) { 490 /* NaT page consumption */ 491 sig = SIGSEGV; 492 code = SEGV_ACCERR; 493 addr = (void __user *) ifa; 494 } else { 495 /* register NaT consumption */ 496 sig = SIGILL; 497 code = ILL_ILLOPN; 498 addr = (void __user *) (regs.cr_iip 499 + ia64_psr(®s)->ri); 500 } 501 siginfo.si_signo = sig; 502 siginfo.si_code = code; 503 siginfo.si_errno = 0; 504 siginfo.si_addr = addr; 505 siginfo.si_imm = vector; 506 siginfo.si_flags = __ISR_VALID; 507 siginfo.si_isr = isr; 508 force_sig_info(sig, &siginfo, current); 509 return; 510 } else if (ia64_done_with_exception(®s)) 511 return; 512 sprintf(buf, "NaT consumption"); 513 break; 514 515 case 31: /* Unsupported Data Reference */ 516 if (user_mode(®s)) { 517 siginfo.si_signo = SIGILL; 518 siginfo.si_code = ILL_ILLOPN; 519 siginfo.si_errno = 0; 520 siginfo.si_addr = (void __user *) iip; 521 siginfo.si_imm = vector; 522 siginfo.si_flags = __ISR_VALID; 523 siginfo.si_isr = isr; 524 force_sig_info(SIGILL, &siginfo, current); 525 return; 526 } 527 sprintf(buf, "Unsupported data reference"); 528 break; 529 530 case 29: /* Debug */ 531 case 35: /* Taken Branch Trap */ 532 case 36: /* Single Step Trap */ 533 if (fsys_mode(current, ®s)) { 534 extern char __kernel_syscall_via_break[]; 535 /* 536 * Got a trap in fsys-mode: Taken Branch Trap 537 * and Single Step trap need special handling; 538 * Debug trap is ignored (we disable it here 539 * and re-enable it in the lower-privilege trap). 540 */ 541 if (unlikely(vector == 29)) { 542 set_thread_flag(TIF_DB_DISABLED); 543 ia64_psr(®s)->db = 0; 544 ia64_psr(®s)->lp = 1; 545 return; 546 } 547 /* re-do the system call via break 0x100000: */ 548 regs.cr_iip = (unsigned long) __kernel_syscall_via_break; 549 ia64_psr(®s)->ri = 0; 550 ia64_psr(®s)->cpl = 3; 551 return; 552 } 553 switch (vector) { 554 default: 555 case 29: 556 siginfo.si_code = TRAP_HWBKPT; 557 #ifdef CONFIG_ITANIUM 558 /* 559 * Erratum 10 (IFA may contain incorrect address) now has 560 * "NoFix" status. There are no plans for fixing this. 561 */ 562 if (ia64_psr(®s)->is == 0) 563 ifa = regs.cr_iip; 564 #endif 565 break; 566 case 35: siginfo.si_code = TRAP_BRANCH; ifa = 0; break; 567 case 36: siginfo.si_code = TRAP_TRACE; ifa = 0; break; 568 } 569 if (notify_die(DIE_FAULT, "ia64_fault", ®s, vector, siginfo.si_code, SIGTRAP) 570 == NOTIFY_STOP) 571 return; 572 siginfo.si_signo = SIGTRAP; 573 siginfo.si_errno = 0; 574 siginfo.si_addr = (void __user *) ifa; 575 siginfo.si_imm = 0; 576 siginfo.si_flags = __ISR_VALID; 577 siginfo.si_isr = isr; 578 force_sig_info(SIGTRAP, &siginfo, current); 579 return; 580 581 case 32: /* fp fault */ 582 case 33: /* fp trap */ 583 result = handle_fpu_swa((vector == 32) ? 1 : 0, ®s, isr); 584 if ((result < 0) || (current->thread.flags & IA64_THREAD_FPEMU_SIGFPE)) { 585 siginfo.si_signo = SIGFPE; 586 siginfo.si_errno = 0; 587 siginfo.si_code = FPE_FLTINV; 588 siginfo.si_addr = (void __user *) iip; 589 siginfo.si_flags = __ISR_VALID; 590 siginfo.si_isr = isr; 591 siginfo.si_imm = 0; 592 force_sig_info(SIGFPE, &siginfo, current); 593 } 594 return; 595 596 case 34: 597 if (isr & 0x2) { 598 /* Lower-Privilege Transfer Trap */ 599 600 /* If we disabled debug traps during an fsyscall, 601 * re-enable them here. 602 */ 603 if (test_thread_flag(TIF_DB_DISABLED)) { 604 clear_thread_flag(TIF_DB_DISABLED); 605 ia64_psr(®s)->db = 1; 606 } 607 608 /* 609 * Just clear PSR.lp and then return immediately: 610 * all the interesting work (e.g., signal delivery) 611 * is done in the kernel exit path. 612 */ 613 ia64_psr(®s)->lp = 0; 614 return; 615 } else { 616 /* Unimplemented Instr. Address Trap */ 617 if (user_mode(®s)) { 618 siginfo.si_signo = SIGILL; 619 siginfo.si_code = ILL_BADIADDR; 620 siginfo.si_errno = 0; 621 siginfo.si_flags = 0; 622 siginfo.si_isr = 0; 623 siginfo.si_imm = 0; 624 siginfo.si_addr = (void __user *) iip; 625 force_sig_info(SIGILL, &siginfo, current); 626 return; 627 } 628 sprintf(buf, "Unimplemented Instruction Address fault"); 629 } 630 break; 631 632 case 45: 633 printk(KERN_ERR "Unexpected IA-32 exception (Trap 45)\n"); 634 printk(KERN_ERR " iip - 0x%lx, ifa - 0x%lx, isr - 0x%lx\n", 635 iip, ifa, isr); 636 force_sig(SIGSEGV, current); 637 return; 638 639 case 46: 640 printk(KERN_ERR "Unexpected IA-32 intercept trap (Trap 46)\n"); 641 printk(KERN_ERR " iip - 0x%lx, ifa - 0x%lx, isr - 0x%lx, iim - 0x%lx\n", 642 iip, ifa, isr, iim); 643 force_sig(SIGSEGV, current); 644 return; 645 646 case 47: 647 sprintf(buf, "IA-32 Interruption Fault (int 0x%lx)", isr >> 16); 648 break; 649 650 default: 651 sprintf(buf, "Fault %lu", vector); 652 break; 653 } 654 if (!die_if_kernel(buf, ®s, error)) 655 force_sig(SIGILL, current); 656 } 657