xref: /openbmc/linux/arch/ia64/kernel/traps.c (revision 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2)
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/config.h>
11 #include <linux/kernel.h>
12 #include <linux/init.h>
13 #include <linux/sched.h>
14 #include <linux/tty.h>
15 #include <linux/vt_kern.h>		/* For unblank_screen() */
16 #include <linux/module.h>       /* for EXPORT_SYMBOL */
17 #include <linux/hardirq.h>
18 
19 #include <asm/fpswa.h>
20 #include <asm/ia32.h>
21 #include <asm/intrinsics.h>
22 #include <asm/processor.h>
23 #include <asm/uaccess.h>
24 
25 extern spinlock_t timerlist_lock;
26 
27 fpswa_interface_t *fpswa_interface;
28 EXPORT_SYMBOL(fpswa_interface);
29 
30 void __init
31 trap_init (void)
32 {
33 	if (ia64_boot_param->fpswa)
34 		/* FPSWA fixup: make the interface pointer a kernel virtual address: */
35 		fpswa_interface = __va(ia64_boot_param->fpswa);
36 }
37 
38 /*
39  * Unlock any spinlocks which will prevent us from getting the message out (timerlist_lock
40  * is acquired through the console unblank code)
41  */
42 void
43 bust_spinlocks (int yes)
44 {
45 	int loglevel_save = console_loglevel;
46 
47 	if (yes) {
48 		oops_in_progress = 1;
49 		return;
50 	}
51 
52 #ifdef CONFIG_VT
53 	unblank_screen();
54 #endif
55 	oops_in_progress = 0;
56 	/*
57 	 * OK, the message is on the console.  Now we call printk() without
58 	 * oops_in_progress set so that printk will give klogd a poke.  Hold onto
59 	 * your hats...
60 	 */
61 	console_loglevel = 15;		/* NMI oopser may have shut the console up */
62 	printk(" ");
63 	console_loglevel = loglevel_save;
64 }
65 
66 void
67 die (const char *str, struct pt_regs *regs, long err)
68 {
69 	static struct {
70 		spinlock_t lock;
71 		u32 lock_owner;
72 		int lock_owner_depth;
73 	} die = {
74 		.lock =			SPIN_LOCK_UNLOCKED,
75 		.lock_owner =		-1,
76 		.lock_owner_depth =	0
77 	};
78 	static int die_counter;
79 
80 	if (die.lock_owner != smp_processor_id()) {
81 		console_verbose();
82 		spin_lock_irq(&die.lock);
83 		die.lock_owner = smp_processor_id();
84 		die.lock_owner_depth = 0;
85 		bust_spinlocks(1);
86 	}
87 
88 	if (++die.lock_owner_depth < 3) {
89 		printk("%s[%d]: %s %ld [%d]\n",
90 			current->comm, current->pid, str, err, ++die_counter);
91 		show_regs(regs);
92   	} else
93 		printk(KERN_ERR "Recursive die() failure, output suppressed\n");
94 
95 	bust_spinlocks(0);
96 	die.lock_owner = -1;
97 	spin_unlock_irq(&die.lock);
98   	do_exit(SIGSEGV);
99 }
100 
101 void
102 die_if_kernel (char *str, struct pt_regs *regs, long err)
103 {
104 	if (!user_mode(regs))
105 		die(str, regs, err);
106 }
107 
108 void
109 ia64_bad_break (unsigned long break_num, struct pt_regs *regs)
110 {
111 	siginfo_t siginfo;
112 	int sig, code;
113 
114 	/* SIGILL, SIGFPE, SIGSEGV, and SIGBUS want these field initialized: */
115 	siginfo.si_addr = (void __user *) (regs->cr_iip + ia64_psr(regs)->ri);
116 	siginfo.si_imm = break_num;
117 	siginfo.si_flags = 0;		/* clear __ISR_VALID */
118 	siginfo.si_isr = 0;
119 
120 	switch (break_num) {
121 	      case 0: /* unknown error (used by GCC for __builtin_abort()) */
122 		die_if_kernel("bugcheck!", regs, break_num);
123 		sig = SIGILL; code = ILL_ILLOPC;
124 		break;
125 
126 	      case 1: /* integer divide by zero */
127 		sig = SIGFPE; code = FPE_INTDIV;
128 		break;
129 
130 	      case 2: /* integer overflow */
131 		sig = SIGFPE; code = FPE_INTOVF;
132 		break;
133 
134 	      case 3: /* range check/bounds check */
135 		sig = SIGFPE; code = FPE_FLTSUB;
136 		break;
137 
138 	      case 4: /* null pointer dereference */
139 		sig = SIGSEGV; code = SEGV_MAPERR;
140 		break;
141 
142 	      case 5: /* misaligned data */
143 		sig = SIGSEGV; code = BUS_ADRALN;
144 		break;
145 
146 	      case 6: /* decimal overflow */
147 		sig = SIGFPE; code = __FPE_DECOVF;
148 		break;
149 
150 	      case 7: /* decimal divide by zero */
151 		sig = SIGFPE; code = __FPE_DECDIV;
152 		break;
153 
154 	      case 8: /* packed decimal error */
155 		sig = SIGFPE; code = __FPE_DECERR;
156 		break;
157 
158 	      case 9: /* invalid ASCII digit */
159 		sig = SIGFPE; code = __FPE_INVASC;
160 		break;
161 
162 	      case 10: /* invalid decimal digit */
163 		sig = SIGFPE; code = __FPE_INVDEC;
164 		break;
165 
166 	      case 11: /* paragraph stack overflow */
167 		sig = SIGSEGV; code = __SEGV_PSTKOVF;
168 		break;
169 
170 	      case 0x3f000 ... 0x3ffff:	/* bundle-update in progress */
171 		sig = SIGILL; code = __ILL_BNDMOD;
172 		break;
173 
174 	      default:
175 		if (break_num < 0x40000 || break_num > 0x100000)
176 			die_if_kernel("Bad break", regs, break_num);
177 
178 		if (break_num < 0x80000) {
179 			sig = SIGILL; code = __ILL_BREAK;
180 		} else {
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  */
198 static inline void
199 disabled_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 #ifndef CONFIG_SMP
206 	{
207 		struct task_struct *fpu_owner
208 			= (struct task_struct *)ia64_get_kr(IA64_KR_FPU_OWNER);
209 
210 		if (ia64_is_local_fpu_owner(current))
211 			return;
212 
213 		if (fpu_owner)
214 			ia64_flush_fph(fpu_owner);
215 	}
216 #endif /* !CONFIG_SMP */
217 	ia64_set_local_fpu_owner(current);
218 	if ((current->thread.flags & IA64_THREAD_FPH_VALID) != 0) {
219 		__ia64_load_fpu(current->thread.fph);
220 		psr->mfh = 0;
221 	} else {
222 		__ia64_init_fpu();
223 		/*
224 		 * Set mfh because the state in thread.fph does not match the state in
225 		 * the fph partition.
226 		 */
227 		psr->mfh = 1;
228 	}
229 }
230 
231 static inline int
232 fp_emulate (int fp_fault, void *bundle, long *ipsr, long *fpsr, long *isr, long *pr, long *ifs,
233 	    struct pt_regs *regs)
234 {
235 	fp_state_t fp_state;
236 	fpswa_ret_t ret;
237 
238 	if (!fpswa_interface)
239 		return -1;
240 
241 	memset(&fp_state, 0, sizeof(fp_state_t));
242 
243 	/*
244 	 * compute fp_state.  only FP registers f6 - f11 are used by the
245 	 * kernel, so set those bits in the mask and set the low volatile
246 	 * pointer to point to these registers.
247 	 */
248 	fp_state.bitmask_low64 = 0xfc0;  /* bit6..bit11 */
249 
250 	fp_state.fp_state_low_volatile = (fp_state_low_volatile_t *) &regs->f6;
251 	/*
252 	 * unsigned long (*EFI_FPSWA) (
253 	 *      unsigned long    trap_type,
254 	 *	void             *Bundle,
255 	 *	unsigned long    *pipsr,
256 	 *	unsigned long    *pfsr,
257 	 *	unsigned long    *pisr,
258 	 *	unsigned long    *ppreds,
259 	 *	unsigned long    *pifs,
260 	 *	void             *fp_state);
261 	 */
262 	ret = (*fpswa_interface->fpswa)((unsigned long) fp_fault, bundle,
263 					(unsigned long *) ipsr, (unsigned long *) fpsr,
264 					(unsigned long *) isr, (unsigned long *) pr,
265 					(unsigned long *) ifs, &fp_state);
266 
267 	return ret.status;
268 }
269 
270 /*
271  * Handle floating-point assist faults and traps.
272  */
273 static int
274 handle_fpu_swa (int fp_fault, struct pt_regs *regs, unsigned long isr)
275 {
276 	long exception, bundle[2];
277 	unsigned long fault_ip;
278 	struct siginfo siginfo;
279 	static int fpu_swa_count = 0;
280 	static unsigned long last_time;
281 
282 	fault_ip = regs->cr_iip;
283 	if (!fp_fault && (ia64_psr(regs)->ri == 0))
284 		fault_ip -= 16;
285 	if (copy_from_user(bundle, (void __user *) fault_ip, sizeof(bundle)))
286 		return -1;
287 
288 	if (jiffies - last_time > 5*HZ)
289 		fpu_swa_count = 0;
290 	if ((fpu_swa_count < 4) && !(current->thread.flags & IA64_THREAD_FPEMU_NOPRINT)) {
291 		last_time = jiffies;
292 		++fpu_swa_count;
293 		printk(KERN_WARNING
294 		       "%s(%d): floating-point assist fault at ip %016lx, isr %016lx\n",
295 		       current->comm, current->pid, regs->cr_iip + ia64_psr(regs)->ri, isr);
296 	}
297 
298 	exception = fp_emulate(fp_fault, bundle, &regs->cr_ipsr, &regs->ar_fpsr, &isr, &regs->pr,
299 			       &regs->cr_ifs, regs);
300 	if (fp_fault) {
301 		if (exception == 0) {
302 			/* emulation was successful */
303 			ia64_increment_ip(regs);
304 		} else if (exception == -1) {
305 			printk(KERN_ERR "handle_fpu_swa: fp_emulate() returned -1\n");
306 			return -1;
307 		} else {
308 			/* is next instruction a trap? */
309 			if (exception & 2) {
310 				ia64_increment_ip(regs);
311 			}
312 			siginfo.si_signo = SIGFPE;
313 			siginfo.si_errno = 0;
314 			siginfo.si_code = __SI_FAULT;	/* default code */
315 			siginfo.si_addr = (void __user *) (regs->cr_iip + ia64_psr(regs)->ri);
316 			if (isr & 0x11) {
317 				siginfo.si_code = FPE_FLTINV;
318 			} else if (isr & 0x22) {
319 				/* denormal operand gets the same si_code as underflow
320 				* see arch/i386/kernel/traps.c:math_error()  */
321 				siginfo.si_code = FPE_FLTUND;
322 			} else if (isr & 0x44) {
323 				siginfo.si_code = FPE_FLTDIV;
324 			}
325 			siginfo.si_isr = isr;
326 			siginfo.si_flags = __ISR_VALID;
327 			siginfo.si_imm = 0;
328 			force_sig_info(SIGFPE, &siginfo, current);
329 		}
330 	} else {
331 		if (exception == -1) {
332 			printk(KERN_ERR "handle_fpu_swa: fp_emulate() returned -1\n");
333 			return -1;
334 		} else if (exception != 0) {
335 			/* raise exception */
336 			siginfo.si_signo = SIGFPE;
337 			siginfo.si_errno = 0;
338 			siginfo.si_code = __SI_FAULT;	/* default code */
339 			siginfo.si_addr = (void __user *) (regs->cr_iip + ia64_psr(regs)->ri);
340 			if (isr & 0x880) {
341 				siginfo.si_code = FPE_FLTOVF;
342 			} else if (isr & 0x1100) {
343 				siginfo.si_code = FPE_FLTUND;
344 			} else if (isr & 0x2200) {
345 				siginfo.si_code = FPE_FLTRES;
346 			}
347 			siginfo.si_isr = isr;
348 			siginfo.si_flags = __ISR_VALID;
349 			siginfo.si_imm = 0;
350 			force_sig_info(SIGFPE, &siginfo, current);
351 		}
352 	}
353 	return 0;
354 }
355 
356 struct illegal_op_return {
357 	unsigned long fkt, arg1, arg2, arg3;
358 };
359 
360 struct illegal_op_return
361 ia64_illegal_op_fault (unsigned long ec, long arg1, long arg2, long arg3,
362 		       long arg4, long arg5, long arg6, long arg7,
363 		       struct pt_regs regs)
364 {
365 	struct illegal_op_return rv;
366 	struct siginfo si;
367 	char buf[128];
368 
369 #ifdef CONFIG_IA64_BRL_EMU
370 	{
371 		extern struct illegal_op_return ia64_emulate_brl (struct pt_regs *, unsigned long);
372 
373 		rv = ia64_emulate_brl(&regs, ec);
374 		if (rv.fkt != (unsigned long) -1)
375 			return rv;
376 	}
377 #endif
378 
379 	sprintf(buf, "IA-64 Illegal operation fault");
380 	die_if_kernel(buf, &regs, 0);
381 
382 	memset(&si, 0, sizeof(si));
383 	si.si_signo = SIGILL;
384 	si.si_code = ILL_ILLOPC;
385 	si.si_addr = (void __user *) (regs.cr_iip + ia64_psr(&regs)->ri);
386 	force_sig_info(SIGILL, &si, current);
387 	rv.fkt = 0;
388 	return rv;
389 }
390 
391 void
392 ia64_fault (unsigned long vector, unsigned long isr, unsigned long ifa,
393 	    unsigned long iim, unsigned long itir, long arg5, long arg6,
394 	    long arg7, struct pt_regs regs)
395 {
396 	unsigned long code, error = isr, iip;
397 	struct siginfo siginfo;
398 	char buf[128];
399 	int result, sig;
400 	static const char *reason[] = {
401 		"IA-64 Illegal Operation fault",
402 		"IA-64 Privileged Operation fault",
403 		"IA-64 Privileged Register fault",
404 		"IA-64 Reserved Register/Field fault",
405 		"Disabled Instruction Set Transition fault",
406 		"Unknown fault 5", "Unknown fault 6", "Unknown fault 7", "Illegal Hazard fault",
407 		"Unknown fault 9", "Unknown fault 10", "Unknown fault 11", "Unknown fault 12",
408 		"Unknown fault 13", "Unknown fault 14", "Unknown fault 15"
409 	};
410 
411 	if ((isr & IA64_ISR_NA) && ((isr & IA64_ISR_CODE_MASK) == IA64_ISR_CODE_LFETCH)) {
412 		/*
413 		 * This fault was due to lfetch.fault, set "ed" bit in the psr to cancel
414 		 * the lfetch.
415 		 */
416 		ia64_psr(&regs)->ed = 1;
417 		return;
418 	}
419 
420 	iip = regs.cr_iip + ia64_psr(&regs)->ri;
421 
422 	switch (vector) {
423 	      case 24: /* General Exception */
424 		code = (isr >> 4) & 0xf;
425 		sprintf(buf, "General Exception: %s%s", reason[code],
426 			(code == 3) ? ((isr & (1UL << 37))
427 				       ? " (RSE access)" : " (data access)") : "");
428 		if (code == 8) {
429 # ifdef CONFIG_IA64_PRINT_HAZARDS
430 			printk("%s[%d]: possible hazard @ ip=%016lx (pr = %016lx)\n",
431 			       current->comm, current->pid,
432 			       regs.cr_iip + ia64_psr(&regs)->ri, regs.pr);
433 # endif
434 			return;
435 		}
436 		break;
437 
438 	      case 25: /* Disabled FP-Register */
439 		if (isr & 2) {
440 			disabled_fph_fault(&regs);
441 			return;
442 		}
443 		sprintf(buf, "Disabled FPL fault---not supposed to happen!");
444 		break;
445 
446 	      case 26: /* NaT Consumption */
447 		if (user_mode(&regs)) {
448 			void __user *addr;
449 
450 			if (((isr >> 4) & 0xf) == 2) {
451 				/* NaT page consumption */
452 				sig = SIGSEGV;
453 				code = SEGV_ACCERR;
454 				addr = (void __user *) ifa;
455 			} else {
456 				/* register NaT consumption */
457 				sig = SIGILL;
458 				code = ILL_ILLOPN;
459 				addr = (void __user *) (regs.cr_iip
460 							+ ia64_psr(&regs)->ri);
461 			}
462 			siginfo.si_signo = sig;
463 			siginfo.si_code = code;
464 			siginfo.si_errno = 0;
465 			siginfo.si_addr = addr;
466 			siginfo.si_imm = vector;
467 			siginfo.si_flags = __ISR_VALID;
468 			siginfo.si_isr = isr;
469 			force_sig_info(sig, &siginfo, current);
470 			return;
471 		} else if (ia64_done_with_exception(&regs))
472 			return;
473 		sprintf(buf, "NaT consumption");
474 		break;
475 
476 	      case 31: /* Unsupported Data Reference */
477 		if (user_mode(&regs)) {
478 			siginfo.si_signo = SIGILL;
479 			siginfo.si_code = ILL_ILLOPN;
480 			siginfo.si_errno = 0;
481 			siginfo.si_addr = (void __user *) iip;
482 			siginfo.si_imm = vector;
483 			siginfo.si_flags = __ISR_VALID;
484 			siginfo.si_isr = isr;
485 			force_sig_info(SIGILL, &siginfo, current);
486 			return;
487 		}
488 		sprintf(buf, "Unsupported data reference");
489 		break;
490 
491 	      case 29: /* Debug */
492 	      case 35: /* Taken Branch Trap */
493 	      case 36: /* Single Step Trap */
494 		if (fsys_mode(current, &regs)) {
495 			extern char __kernel_syscall_via_break[];
496 			/*
497 			 * Got a trap in fsys-mode: Taken Branch Trap and Single Step trap
498 			 * need special handling; Debug trap is not supposed to happen.
499 			 */
500 			if (unlikely(vector == 29)) {
501 				die("Got debug trap in fsys-mode---not supposed to happen!",
502 				    &regs, 0);
503 				return;
504 			}
505 			/* re-do the system call via break 0x100000: */
506 			regs.cr_iip = (unsigned long) __kernel_syscall_via_break;
507 			ia64_psr(&regs)->ri = 0;
508 			ia64_psr(&regs)->cpl = 3;
509 			return;
510 		}
511 		switch (vector) {
512 		      case 29:
513 			siginfo.si_code = TRAP_HWBKPT;
514 #ifdef CONFIG_ITANIUM
515 			/*
516 			 * Erratum 10 (IFA may contain incorrect address) now has
517 			 * "NoFix" status.  There are no plans for fixing this.
518 			 */
519 			if (ia64_psr(&regs)->is == 0)
520 			  ifa = regs.cr_iip;
521 #endif
522 			break;
523 		      case 35: siginfo.si_code = TRAP_BRANCH; ifa = 0; break;
524 		      case 36: siginfo.si_code = TRAP_TRACE; ifa = 0; break;
525 		}
526 		siginfo.si_signo = SIGTRAP;
527 		siginfo.si_errno = 0;
528 		siginfo.si_addr  = (void __user *) ifa;
529 		siginfo.si_imm   = 0;
530 		siginfo.si_flags = __ISR_VALID;
531 		siginfo.si_isr   = isr;
532 		force_sig_info(SIGTRAP, &siginfo, current);
533 		return;
534 
535 	      case 32: /* fp fault */
536 	      case 33: /* fp trap */
537 		result = handle_fpu_swa((vector == 32) ? 1 : 0, &regs, isr);
538 		if ((result < 0) || (current->thread.flags & IA64_THREAD_FPEMU_SIGFPE)) {
539 			siginfo.si_signo = SIGFPE;
540 			siginfo.si_errno = 0;
541 			siginfo.si_code = FPE_FLTINV;
542 			siginfo.si_addr = (void __user *) iip;
543 			siginfo.si_flags = __ISR_VALID;
544 			siginfo.si_isr = isr;
545 			siginfo.si_imm = 0;
546 			force_sig_info(SIGFPE, &siginfo, current);
547 		}
548 		return;
549 
550 	      case 34:
551 		if (isr & 0x2) {
552 			/* Lower-Privilege Transfer Trap */
553 			/*
554 			 * Just clear PSR.lp and then return immediately: all the
555 			 * interesting work (e.g., signal delivery is done in the kernel
556 			 * exit path).
557 			 */
558 			ia64_psr(&regs)->lp = 0;
559 			return;
560 		} else {
561 			/* Unimplemented Instr. Address Trap */
562 			if (user_mode(&regs)) {
563 				siginfo.si_signo = SIGILL;
564 				siginfo.si_code = ILL_BADIADDR;
565 				siginfo.si_errno = 0;
566 				siginfo.si_flags = 0;
567 				siginfo.si_isr = 0;
568 				siginfo.si_imm = 0;
569 				siginfo.si_addr = (void __user *) iip;
570 				force_sig_info(SIGILL, &siginfo, current);
571 				return;
572 			}
573 			sprintf(buf, "Unimplemented Instruction Address fault");
574 		}
575 		break;
576 
577 	      case 45:
578 #ifdef CONFIG_IA32_SUPPORT
579 		if (ia32_exception(&regs, isr) == 0)
580 			return;
581 #endif
582 		printk(KERN_ERR "Unexpected IA-32 exception (Trap 45)\n");
583 		printk(KERN_ERR "  iip - 0x%lx, ifa - 0x%lx, isr - 0x%lx\n",
584 		       iip, ifa, isr);
585 		force_sig(SIGSEGV, current);
586 		break;
587 
588 	      case 46:
589 #ifdef CONFIG_IA32_SUPPORT
590 		if (ia32_intercept(&regs, isr) == 0)
591 			return;
592 #endif
593 		printk(KERN_ERR "Unexpected IA-32 intercept trap (Trap 46)\n");
594 		printk(KERN_ERR "  iip - 0x%lx, ifa - 0x%lx, isr - 0x%lx, iim - 0x%lx\n",
595 		       iip, ifa, isr, iim);
596 		force_sig(SIGSEGV, current);
597 		return;
598 
599 	      case 47:
600 		sprintf(buf, "IA-32 Interruption Fault (int 0x%lx)", isr >> 16);
601 		break;
602 
603 	      default:
604 		sprintf(buf, "Fault %lu", vector);
605 		break;
606 	}
607 	die_if_kernel(buf, &regs, error);
608 	force_sig(SIGILL, current);
609 }
610