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1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Architecture-specific trap handling.
4 *
5 * Copyright (C) 1998-2003 Hewlett-Packard Co
6 * David Mosberger-Tang <davidm@hpl.hp.com>
7 *
8 * 05/12/00 grao <goutham.rao@intel.com> : added isr in siginfo for SIGFPE
9 */
10
11#include <linux/kernel.h>
12#include <linux/init.h>
13#include <linux/sched/signal.h>
14#include <linux/sched/debug.h>
15#include <linux/tty.h>
16#include <linux/vt_kern.h> /* For unblank_screen() */
17#include <linux/export.h>
18#include <linux/extable.h>
19#include <linux/hardirq.h>
20#include <linux/kprobes.h>
21#include <linux/delay.h> /* for ssleep() */
22#include <linux/kdebug.h>
23#include <linux/uaccess.h>
24
25#include <asm/fpswa.h>
26#include <asm/intrinsics.h>
27#include <asm/processor.h>
28#include <asm/exception.h>
29#include <asm/setup.h>
30
31fpswa_interface_t *fpswa_interface;
32EXPORT_SYMBOL(fpswa_interface);
33
34void __init
35trap_init (void)
36{
37 if (ia64_boot_param->fpswa)
38 /* FPSWA fixup: make the interface pointer a kernel virtual address: */
39 fpswa_interface = __va(ia64_boot_param->fpswa);
40}
41
42int
43die (const char *str, struct pt_regs *regs, long err)
44{
45 static struct {
46 spinlock_t lock;
47 u32 lock_owner;
48 int lock_owner_depth;
49 } die = {
50 .lock = __SPIN_LOCK_UNLOCKED(die.lock),
51 .lock_owner = -1,
52 .lock_owner_depth = 0
53 };
54 static int die_counter;
55 int cpu = get_cpu();
56
57 if (die.lock_owner != cpu) {
58 console_verbose();
59 spin_lock_irq(&die.lock);
60 die.lock_owner = cpu;
61 die.lock_owner_depth = 0;
62 bust_spinlocks(1);
63 }
64 put_cpu();
65
66 if (++die.lock_owner_depth < 3) {
67 printk("%s[%d]: %s %ld [%d]\n",
68 current->comm, task_pid_nr(current), str, err, ++die_counter);
69 if (notify_die(DIE_OOPS, str, regs, err, 255, SIGSEGV)
70 != NOTIFY_STOP)
71 show_regs(regs);
72 else
73 regs = NULL;
74 } else
75 printk(KERN_ERR "Recursive die() failure, output suppressed\n");
76
77 bust_spinlocks(0);
78 die.lock_owner = -1;
79 add_taint(TAINT_DIE, LOCKDEP_NOW_UNRELIABLE);
80 spin_unlock_irq(&die.lock);
81
82 if (!regs)
83 return 1;
84
85 if (panic_on_oops)
86 panic("Fatal exception");
87
88 do_exit(SIGSEGV);
89 return 0;
90}
91
92int
93die_if_kernel (char *str, struct pt_regs *regs, long err)
94{
95 if (!user_mode(regs))
96 return die(str, regs, err);
97 return 0;
98}
99
100void
101__kprobes ia64_bad_break (unsigned long break_num, struct pt_regs *regs)
102{
103 siginfo_t siginfo;
104 int sig, code;
105
106 /* SIGILL, SIGFPE, SIGSEGV, and SIGBUS want these field initialized: */
107 siginfo.si_addr = (void __user *) (regs->cr_iip + ia64_psr(regs)->ri);
108 siginfo.si_imm = break_num;
109 siginfo.si_flags = 0; /* clear __ISR_VALID */
110 siginfo.si_isr = 0;
111
112 switch (break_num) {
113 case 0: /* unknown error (used by GCC for __builtin_abort()) */
114 if (notify_die(DIE_BREAK, "break 0", regs, break_num, TRAP_BRKPT, SIGTRAP)
115 == NOTIFY_STOP)
116 return;
117 if (die_if_kernel("bugcheck!", regs, break_num))
118 return;
119 sig = SIGILL; code = ILL_ILLOPC;
120 break;
121
122 case 1: /* integer divide by zero */
123 sig = SIGFPE; code = FPE_INTDIV;
124 break;
125
126 case 2: /* integer overflow */
127 sig = SIGFPE; code = FPE_INTOVF;
128 break;
129
130 case 3: /* range check/bounds check */
131 sig = SIGFPE; code = FPE_FLTSUB;
132 break;
133
134 case 4: /* null pointer dereference */
135 sig = SIGSEGV; code = SEGV_MAPERR;
136 break;
137
138 case 5: /* misaligned data */
139 sig = SIGSEGV; code = BUS_ADRALN;
140 break;
141
142 case 6: /* decimal overflow */
143 sig = SIGFPE; code = __FPE_DECOVF;
144 break;
145
146 case 7: /* decimal divide by zero */
147 sig = SIGFPE; code = __FPE_DECDIV;
148 break;
149
150 case 8: /* packed decimal error */
151 sig = SIGFPE; code = __FPE_DECERR;
152 break;
153
154 case 9: /* invalid ASCII digit */
155 sig = SIGFPE; code = __FPE_INVASC;
156 break;
157
158 case 10: /* invalid decimal digit */
159 sig = SIGFPE; code = __FPE_INVDEC;
160 break;
161
162 case 11: /* paragraph stack overflow */
163 sig = SIGSEGV; code = __SEGV_PSTKOVF;
164 break;
165
166 case 0x3f000 ... 0x3ffff: /* bundle-update in progress */
167 sig = SIGILL; code = __ILL_BNDMOD;
168 break;
169
170 default:
171 if ((break_num < 0x40000 || break_num > 0x100000)
172 && die_if_kernel("Bad break", regs, break_num))
173 return;
174
175 if (break_num < 0x80000) {
176 sig = SIGILL; code = __ILL_BREAK;
177 } else {
178 if (notify_die(DIE_BREAK, "bad break", regs, break_num, TRAP_BRKPT, SIGTRAP)
179 == NOTIFY_STOP)
180 return;
181 sig = SIGTRAP; code = TRAP_BRKPT;
182 }
183 }
184 siginfo.si_signo = sig;
185 siginfo.si_errno = 0;
186 siginfo.si_code = code;
187 force_sig_info(sig, &siginfo, current);
188}
189
190/*
191 * disabled_fph_fault() is called when a user-level process attempts to access f32..f127
192 * and it doesn't own the fp-high register partition. When this happens, we save the
193 * current fph partition in the task_struct of the fpu-owner (if necessary) and then load
194 * the fp-high partition of the current task (if necessary). Note that the kernel has
195 * access to fph by the time we get here, as the IVT's "Disabled FP-Register" handler takes
196 * care of clearing psr.dfh.
197 */
198static inline void
199disabled_fph_fault (struct pt_regs *regs)
200{
201 struct ia64_psr *psr = ia64_psr(regs);
202
203 /* first, grant user-level access to fph partition: */
204 psr->dfh = 0;
205
206 /*
207 * Make sure that no other task gets in on this processor
208 * while we're claiming the FPU
209 */
210 preempt_disable();
211#ifndef CONFIG_SMP
212 {
213 struct task_struct *fpu_owner
214 = (struct task_struct *)ia64_get_kr(IA64_KR_FPU_OWNER);
215
216 if (ia64_is_local_fpu_owner(current)) {
217 preempt_enable_no_resched();
218 return;
219 }
220
221 if (fpu_owner)
222 ia64_flush_fph(fpu_owner);
223 }
224#endif /* !CONFIG_SMP */
225 ia64_set_local_fpu_owner(current);
226 if ((current->thread.flags & IA64_THREAD_FPH_VALID) != 0) {
227 __ia64_load_fpu(current->thread.fph);
228 psr->mfh = 0;
229 } else {
230 __ia64_init_fpu();
231 /*
232 * Set mfh because the state in thread.fph does not match the state in
233 * the fph partition.
234 */
235 psr->mfh = 1;
236 }
237 preempt_enable_no_resched();
238}
239
240static inline int
241fp_emulate (int fp_fault, void *bundle, long *ipsr, long *fpsr, long *isr, long *pr, long *ifs,
242 struct pt_regs *regs)
243{
244 fp_state_t fp_state;
245 fpswa_ret_t ret;
246
247 if (!fpswa_interface)
248 return -1;
249
250 memset(&fp_state, 0, sizeof(fp_state_t));
251
252 /*
253 * compute fp_state. only FP registers f6 - f11 are used by the
254 * kernel, so set those bits in the mask and set the low volatile
255 * pointer to point to these registers.
256 */
257 fp_state.bitmask_low64 = 0xfc0; /* bit6..bit11 */
258
259 fp_state.fp_state_low_volatile = (fp_state_low_volatile_t *) ®s->f6;
260 /*
261 * unsigned long (*EFI_FPSWA) (
262 * unsigned long trap_type,
263 * void *Bundle,
264 * unsigned long *pipsr,
265 * unsigned long *pfsr,
266 * unsigned long *pisr,
267 * unsigned long *ppreds,
268 * unsigned long *pifs,
269 * void *fp_state);
270 */
271 ret = (*fpswa_interface->fpswa)((unsigned long) fp_fault, bundle,
272 (unsigned long *) ipsr, (unsigned long *) fpsr,
273 (unsigned long *) isr, (unsigned long *) pr,
274 (unsigned long *) ifs, &fp_state);
275
276 return ret.status;
277}
278
279struct fpu_swa_msg {
280 unsigned long count;
281 unsigned long time;
282};
283static DEFINE_PER_CPU(struct fpu_swa_msg, cpulast);
284DECLARE_PER_CPU(struct fpu_swa_msg, cpulast);
285static struct fpu_swa_msg last __cacheline_aligned;
286
287
288/*
289 * Handle floating-point assist faults and traps.
290 */
291static int
292handle_fpu_swa (int fp_fault, struct pt_regs *regs, unsigned long isr)
293{
294 long exception, bundle[2];
295 unsigned long fault_ip;
296 struct siginfo siginfo;
297
298 fault_ip = regs->cr_iip;
299 if (!fp_fault && (ia64_psr(regs)->ri == 0))
300 fault_ip -= 16;
301 if (copy_from_user(bundle, (void __user *) fault_ip, sizeof(bundle)))
302 return -1;
303
304 if (!(current->thread.flags & IA64_THREAD_FPEMU_NOPRINT)) {
305 unsigned long count, current_jiffies = jiffies;
306 struct fpu_swa_msg *cp = this_cpu_ptr(&cpulast);
307
308 if (unlikely(current_jiffies > cp->time))
309 cp->count = 0;
310 if (unlikely(cp->count < 5)) {
311 cp->count++;
312 cp->time = current_jiffies + 5 * HZ;
313
314 /* minimize races by grabbing a copy of count BEFORE checking last.time. */
315 count = last.count;
316 barrier();
317
318 /*
319 * Lower 4 bits are used as a count. Upper bits are a sequence
320 * number that is updated when count is reset. The cmpxchg will
321 * fail is seqno has changed. This minimizes mutiple cpus
322 * resetting the count.
323 */
324 if (current_jiffies > last.time)
325 (void) cmpxchg_acq(&last.count, count, 16 + (count & ~15));
326
327 /* used fetchadd to atomically update the count */
328 if ((last.count & 15) < 5 && (ia64_fetchadd(1, &last.count, acq) & 15) < 5) {
329 last.time = current_jiffies + 5 * HZ;
330 printk(KERN_WARNING
331 "%s(%d): floating-point assist fault at ip %016lx, isr %016lx\n",
332 current->comm, task_pid_nr(current), regs->cr_iip + ia64_psr(regs)->ri, isr);
333 }
334 }
335 }
336
337 exception = fp_emulate(fp_fault, bundle, ®s->cr_ipsr, ®s->ar_fpsr, &isr, ®s->pr,
338 ®s->cr_ifs, regs);
339 if (fp_fault) {
340 if (exception == 0) {
341 /* emulation was successful */
342 ia64_increment_ip(regs);
343 } else if (exception == -1) {
344 printk(KERN_ERR "handle_fpu_swa: fp_emulate() returned -1\n");
345 return -1;
346 } else {
347 /* is next instruction a trap? */
348 if (exception & 2) {
349 ia64_increment_ip(regs);
350 }
351 siginfo.si_signo = SIGFPE;
352 siginfo.si_errno = 0;
353 siginfo.si_code = FPE_FIXME; /* default code */
354 siginfo.si_addr = (void __user *) (regs->cr_iip + ia64_psr(regs)->ri);
355 if (isr & 0x11) {
356 siginfo.si_code = FPE_FLTINV;
357 } else if (isr & 0x22) {
358 /* denormal operand gets the same si_code as underflow
359 * see arch/i386/kernel/traps.c:math_error() */
360 siginfo.si_code = FPE_FLTUND;
361 } else if (isr & 0x44) {
362 siginfo.si_code = FPE_FLTDIV;
363 }
364 siginfo.si_isr = isr;
365 siginfo.si_flags = __ISR_VALID;
366 siginfo.si_imm = 0;
367 force_sig_info(SIGFPE, &siginfo, current);
368 }
369 } else {
370 if (exception == -1) {
371 printk(KERN_ERR "handle_fpu_swa: fp_emulate() returned -1\n");
372 return -1;
373 } else if (exception != 0) {
374 /* raise exception */
375 siginfo.si_signo = SIGFPE;
376 siginfo.si_errno = 0;
377 siginfo.si_code = FPE_FIXME; /* default code */
378 siginfo.si_addr = (void __user *) (regs->cr_iip + ia64_psr(regs)->ri);
379 if (isr & 0x880) {
380 siginfo.si_code = FPE_FLTOVF;
381 } else if (isr & 0x1100) {
382 siginfo.si_code = FPE_FLTUND;
383 } else if (isr & 0x2200) {
384 siginfo.si_code = FPE_FLTRES;
385 }
386 siginfo.si_isr = isr;
387 siginfo.si_flags = __ISR_VALID;
388 siginfo.si_imm = 0;
389 force_sig_info(SIGFPE, &siginfo, current);
390 }
391 }
392 return 0;
393}
394
395struct illegal_op_return {
396 unsigned long fkt, arg1, arg2, arg3;
397};
398
399struct illegal_op_return
400ia64_illegal_op_fault (unsigned long ec, long arg1, long arg2, long arg3,
401 long arg4, long arg5, long arg6, long arg7,
402 struct pt_regs regs)
403{
404 struct illegal_op_return rv;
405 struct siginfo si;
406 char buf[128];
407
408#ifdef CONFIG_IA64_BRL_EMU
409 {
410 extern struct illegal_op_return ia64_emulate_brl (struct pt_regs *, unsigned long);
411
412 rv = ia64_emulate_brl(®s, ec);
413 if (rv.fkt != (unsigned long) -1)
414 return rv;
415 }
416#endif
417
418 sprintf(buf, "IA-64 Illegal operation fault");
419 rv.fkt = 0;
420 if (die_if_kernel(buf, ®s, 0))
421 return rv;
422
423 memset(&si, 0, sizeof(si));
424 si.si_signo = SIGILL;
425 si.si_code = ILL_ILLOPC;
426 si.si_addr = (void __user *) (regs.cr_iip + ia64_psr(®s)->ri);
427 force_sig_info(SIGILL, &si, current);
428 return rv;
429}
430
431void __kprobes
432ia64_fault (unsigned long vector, unsigned long isr, unsigned long ifa,
433 unsigned long iim, unsigned long itir, long arg5, long arg6,
434 long arg7, struct pt_regs regs)
435{
436 unsigned long code, error = isr, iip;
437 struct siginfo siginfo;
438 char buf[128];
439 int result, sig;
440 static const char *reason[] = {
441 "IA-64 Illegal Operation fault",
442 "IA-64 Privileged Operation fault",
443 "IA-64 Privileged Register fault",
444 "IA-64 Reserved Register/Field fault",
445 "Disabled Instruction Set Transition fault",
446 "Unknown fault 5", "Unknown fault 6", "Unknown fault 7", "Illegal Hazard fault",
447 "Unknown fault 9", "Unknown fault 10", "Unknown fault 11", "Unknown fault 12",
448 "Unknown fault 13", "Unknown fault 14", "Unknown fault 15"
449 };
450
451 if ((isr & IA64_ISR_NA) && ((isr & IA64_ISR_CODE_MASK) == IA64_ISR_CODE_LFETCH)) {
452 /*
453 * This fault was due to lfetch.fault, set "ed" bit in the psr to cancel
454 * the lfetch.
455 */
456 ia64_psr(®s)->ed = 1;
457 return;
458 }
459
460 iip = regs.cr_iip + ia64_psr(®s)->ri;
461
462 switch (vector) {
463 case 24: /* General Exception */
464 code = (isr >> 4) & 0xf;
465 sprintf(buf, "General Exception: %s%s", reason[code],
466 (code == 3) ? ((isr & (1UL << 37))
467 ? " (RSE access)" : " (data access)") : "");
468 if (code == 8) {
469# ifdef CONFIG_IA64_PRINT_HAZARDS
470 printk("%s[%d]: possible hazard @ ip=%016lx (pr = %016lx)\n",
471 current->comm, task_pid_nr(current),
472 regs.cr_iip + ia64_psr(®s)->ri, regs.pr);
473# endif
474 return;
475 }
476 break;
477
478 case 25: /* Disabled FP-Register */
479 if (isr & 2) {
480 disabled_fph_fault(®s);
481 return;
482 }
483 sprintf(buf, "Disabled FPL fault---not supposed to happen!");
484 break;
485
486 case 26: /* NaT Consumption */
487 if (user_mode(®s)) {
488 void __user *addr;
489
490 if (((isr >> 4) & 0xf) == 2) {
491 /* NaT page consumption */
492 sig = SIGSEGV;
493 code = SEGV_ACCERR;
494 addr = (void __user *) ifa;
495 } else {
496 /* register NaT consumption */
497 sig = SIGILL;
498 code = ILL_ILLOPN;
499 addr = (void __user *) (regs.cr_iip
500 + ia64_psr(®s)->ri);
501 }
502 siginfo.si_signo = sig;
503 siginfo.si_code = code;
504 siginfo.si_errno = 0;
505 siginfo.si_addr = addr;
506 siginfo.si_imm = vector;
507 siginfo.si_flags = __ISR_VALID;
508 siginfo.si_isr = isr;
509 force_sig_info(sig, &siginfo, current);
510 return;
511 } else if (ia64_done_with_exception(®s))
512 return;
513 sprintf(buf, "NaT consumption");
514 break;
515
516 case 31: /* Unsupported Data Reference */
517 if (user_mode(®s)) {
518 siginfo.si_signo = SIGILL;
519 siginfo.si_code = ILL_ILLOPN;
520 siginfo.si_errno = 0;
521 siginfo.si_addr = (void __user *) iip;
522 siginfo.si_imm = vector;
523 siginfo.si_flags = __ISR_VALID;
524 siginfo.si_isr = isr;
525 force_sig_info(SIGILL, &siginfo, current);
526 return;
527 }
528 sprintf(buf, "Unsupported data reference");
529 break;
530
531 case 29: /* Debug */
532 case 35: /* Taken Branch Trap */
533 case 36: /* Single Step Trap */
534 if (fsys_mode(current, ®s)) {
535 extern char __kernel_syscall_via_break[];
536 /*
537 * Got a trap in fsys-mode: Taken Branch Trap
538 * and Single Step trap need special handling;
539 * Debug trap is ignored (we disable it here
540 * and re-enable it in the lower-privilege trap).
541 */
542 if (unlikely(vector == 29)) {
543 set_thread_flag(TIF_DB_DISABLED);
544 ia64_psr(®s)->db = 0;
545 ia64_psr(®s)->lp = 1;
546 return;
547 }
548 /* re-do the system call via break 0x100000: */
549 regs.cr_iip = (unsigned long) __kernel_syscall_via_break;
550 ia64_psr(®s)->ri = 0;
551 ia64_psr(®s)->cpl = 3;
552 return;
553 }
554 switch (vector) {
555 default:
556 case 29:
557 siginfo.si_code = TRAP_HWBKPT;
558#ifdef CONFIG_ITANIUM
559 /*
560 * Erratum 10 (IFA may contain incorrect address) now has
561 * "NoFix" status. There are no plans for fixing this.
562 */
563 if (ia64_psr(®s)->is == 0)
564 ifa = regs.cr_iip;
565#endif
566 break;
567 case 35: siginfo.si_code = TRAP_BRANCH; ifa = 0; break;
568 case 36: siginfo.si_code = TRAP_TRACE; ifa = 0; break;
569 }
570 if (notify_die(DIE_FAULT, "ia64_fault", ®s, vector, siginfo.si_code, SIGTRAP)
571 == NOTIFY_STOP)
572 return;
573 siginfo.si_signo = SIGTRAP;
574 siginfo.si_errno = 0;
575 siginfo.si_addr = (void __user *) ifa;
576 siginfo.si_imm = 0;
577 siginfo.si_flags = __ISR_VALID;
578 siginfo.si_isr = isr;
579 force_sig_info(SIGTRAP, &siginfo, current);
580 return;
581
582 case 32: /* fp fault */
583 case 33: /* fp trap */
584 result = handle_fpu_swa((vector == 32) ? 1 : 0, ®s, isr);
585 if ((result < 0) || (current->thread.flags & IA64_THREAD_FPEMU_SIGFPE)) {
586 siginfo.si_signo = SIGFPE;
587 siginfo.si_errno = 0;
588 siginfo.si_code = FPE_FLTINV;
589 siginfo.si_addr = (void __user *) iip;
590 siginfo.si_flags = __ISR_VALID;
591 siginfo.si_isr = isr;
592 siginfo.si_imm = 0;
593 force_sig_info(SIGFPE, &siginfo, current);
594 }
595 return;
596
597 case 34:
598 if (isr & 0x2) {
599 /* Lower-Privilege Transfer Trap */
600
601 /* If we disabled debug traps during an fsyscall,
602 * re-enable them here.
603 */
604 if (test_thread_flag(TIF_DB_DISABLED)) {
605 clear_thread_flag(TIF_DB_DISABLED);
606 ia64_psr(®s)->db = 1;
607 }
608
609 /*
610 * Just clear PSR.lp and then return immediately:
611 * all the interesting work (e.g., signal delivery)
612 * is done in the kernel exit path.
613 */
614 ia64_psr(®s)->lp = 0;
615 return;
616 } else {
617 /* Unimplemented Instr. Address Trap */
618 if (user_mode(®s)) {
619 siginfo.si_signo = SIGILL;
620 siginfo.si_code = ILL_BADIADDR;
621 siginfo.si_errno = 0;
622 siginfo.si_flags = 0;
623 siginfo.si_isr = 0;
624 siginfo.si_imm = 0;
625 siginfo.si_addr = (void __user *) iip;
626 force_sig_info(SIGILL, &siginfo, current);
627 return;
628 }
629 sprintf(buf, "Unimplemented Instruction Address fault");
630 }
631 break;
632
633 case 45:
634 printk(KERN_ERR "Unexpected IA-32 exception (Trap 45)\n");
635 printk(KERN_ERR " iip - 0x%lx, ifa - 0x%lx, isr - 0x%lx\n",
636 iip, ifa, isr);
637 force_sig(SIGSEGV, current);
638 return;
639
640 case 46:
641 printk(KERN_ERR "Unexpected IA-32 intercept trap (Trap 46)\n");
642 printk(KERN_ERR " iip - 0x%lx, ifa - 0x%lx, isr - 0x%lx, iim - 0x%lx\n",
643 iip, ifa, isr, iim);
644 force_sig(SIGSEGV, current);
645 return;
646
647 case 47:
648 sprintf(buf, "IA-32 Interruption Fault (int 0x%lx)", isr >> 16);
649 break;
650
651 default:
652 sprintf(buf, "Fault %lu", vector);
653 break;
654 }
655 if (!die_if_kernel(buf, ®s, error))
656 force_sig(SIGILL, current);
657}