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v6.2
  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	make_task_dead(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	int sig, code;
104
 
 
 
 
 
 
105	switch (break_num) {
106	      case 0: /* unknown error (used by GCC for __builtin_abort()) */
107		if (notify_die(DIE_BREAK, "break 0", regs, break_num, TRAP_BRKPT, SIGTRAP)
108			       	== NOTIFY_STOP)
109			return;
110		if (die_if_kernel("bugcheck!", regs, break_num))
111			return;
112		sig = SIGILL; code = ILL_ILLOPC;
113		break;
114
115	      case 1: /* integer divide by zero */
116		sig = SIGFPE; code = FPE_INTDIV;
117		break;
118
119	      case 2: /* integer overflow */
120		sig = SIGFPE; code = FPE_INTOVF;
121		break;
122
123	      case 3: /* range check/bounds check */
124		sig = SIGFPE; code = FPE_FLTSUB;
125		break;
126
127	      case 4: /* null pointer dereference */
128		sig = SIGSEGV; code = SEGV_MAPERR;
129		break;
130
131	      case 5: /* misaligned data */
132		sig = SIGSEGV; code = BUS_ADRALN;
133		break;
134
135	      case 6: /* decimal overflow */
136		sig = SIGFPE; code = __FPE_DECOVF;
137		break;
138
139	      case 7: /* decimal divide by zero */
140		sig = SIGFPE; code = __FPE_DECDIV;
141		break;
142
143	      case 8: /* packed decimal error */
144		sig = SIGFPE; code = __FPE_DECERR;
145		break;
146
147	      case 9: /* invalid ASCII digit */
148		sig = SIGFPE; code = __FPE_INVASC;
149		break;
150
151	      case 10: /* invalid decimal digit */
152		sig = SIGFPE; code = __FPE_INVDEC;
153		break;
154
155	      case 11: /* paragraph stack overflow */
156		sig = SIGSEGV; code = __SEGV_PSTKOVF;
157		break;
158
159	      case 0x3f000 ... 0x3ffff:	/* bundle-update in progress */
160		sig = SIGILL; code = __ILL_BNDMOD;
161		break;
162
163	      default:
164		if ((break_num < 0x40000 || break_num > 0x100000)
165		    && die_if_kernel("Bad break", regs, break_num))
166			return;
167
168		if (break_num < 0x80000) {
169			sig = SIGILL; code = __ILL_BREAK;
170		} else {
171			if (notify_die(DIE_BREAK, "bad break", regs, break_num, TRAP_BRKPT, SIGTRAP)
172					== NOTIFY_STOP)
173				return;
174			sig = SIGTRAP; code = TRAP_BRKPT;
175		}
176	}
177	force_sig_fault(sig, code,
178			(void __user *) (regs->cr_iip + ia64_psr(regs)->ri),
179			break_num, 0 /* clear __ISR_VALID */, 0);
 
180}
181
182/*
183 * disabled_fph_fault() is called when a user-level process attempts to access f32..f127
184 * and it doesn't own the fp-high register partition.  When this happens, we save the
185 * current fph partition in the task_struct of the fpu-owner (if necessary) and then load
186 * the fp-high partition of the current task (if necessary).  Note that the kernel has
187 * access to fph by the time we get here, as the IVT's "Disabled FP-Register" handler takes
188 * care of clearing psr.dfh.
189 */
190static inline void
191disabled_fph_fault (struct pt_regs *regs)
192{
193	struct ia64_psr *psr = ia64_psr(regs);
194
195	/* first, grant user-level access to fph partition: */
196	psr->dfh = 0;
197
198	/*
199	 * Make sure that no other task gets in on this processor
200	 * while we're claiming the FPU
201	 */
202	preempt_disable();
203#ifndef CONFIG_SMP
204	{
205		struct task_struct *fpu_owner
206			= (struct task_struct *)ia64_get_kr(IA64_KR_FPU_OWNER);
207
208		if (ia64_is_local_fpu_owner(current)) {
209			preempt_enable_no_resched();
210			return;
211		}
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	preempt_enable_no_resched();
230}
231
232static inline int
233fp_emulate (int fp_fault, void *bundle, long *ipsr, long *fpsr, long *isr, long *pr, long *ifs,
234	    struct pt_regs *regs)
235{
236	fp_state_t fp_state;
237	fpswa_ret_t ret;
238
239	if (!fpswa_interface)
240		return -1;
241
242	memset(&fp_state, 0, sizeof(fp_state_t));
243
244	/*
245	 * compute fp_state.  only FP registers f6 - f11 are used by the
246	 * kernel, so set those bits in the mask and set the low volatile
247	 * pointer to point to these registers.
248	 */
249	fp_state.bitmask_low64 = 0xfc0;  /* bit6..bit11 */
250
251	fp_state.fp_state_low_volatile = (fp_state_low_volatile_t *) &regs->f6;
252	/*
253	 * unsigned long (*EFI_FPSWA) (
254	 *      unsigned long    trap_type,
255	 *	void             *Bundle,
256	 *	unsigned long    *pipsr,
257	 *	unsigned long    *pfsr,
258	 *	unsigned long    *pisr,
259	 *	unsigned long    *ppreds,
260	 *	unsigned long    *pifs,
261	 *	void             *fp_state);
262	 */
263	ret = (*fpswa_interface->fpswa)((unsigned long) fp_fault, bundle,
264					(unsigned long *) ipsr, (unsigned long *) fpsr,
265					(unsigned long *) isr, (unsigned long *) pr,
266					(unsigned long *) ifs, &fp_state);
267
268	return ret.status;
269}
270
271struct fpu_swa_msg {
272	unsigned long count;
273	unsigned long time;
274};
275static DEFINE_PER_CPU(struct fpu_swa_msg, cpulast);
276DECLARE_PER_CPU(struct fpu_swa_msg, cpulast);
277static struct fpu_swa_msg last __cacheline_aligned;
278
279
280/*
281 * Handle floating-point assist faults and traps.
282 */
283static int
284handle_fpu_swa (int fp_fault, struct pt_regs *regs, unsigned long isr)
285{
286	long exception, bundle[2];
287	unsigned long fault_ip;
 
288
289	fault_ip = regs->cr_iip;
290	if (!fp_fault && (ia64_psr(regs)->ri == 0))
291		fault_ip -= 16;
292	if (copy_from_user(bundle, (void __user *) fault_ip, sizeof(bundle)))
293		return -1;
294
295	if (!(current->thread.flags & IA64_THREAD_FPEMU_NOPRINT))  {
296		unsigned long count, current_jiffies = jiffies;
297		struct fpu_swa_msg *cp = this_cpu_ptr(&cpulast);
298
299		if (unlikely(current_jiffies > cp->time))
300			cp->count = 0;
301		if (unlikely(cp->count < 5)) {
302			cp->count++;
303			cp->time = current_jiffies + 5 * HZ;
304
305			/* minimize races by grabbing a copy of count BEFORE checking last.time. */
306			count = last.count;
307			barrier();
308
309			/*
310			 * Lower 4 bits are used as a count. Upper bits are a sequence
311			 * number that is updated when count is reset. The cmpxchg will
312			 * fail is seqno has changed. This minimizes multiple cpus
313			 * resetting the count.
314			 */
315			if (current_jiffies > last.time)
316				(void) cmpxchg_acq(&last.count, count, 16 + (count & ~15));
317
318			/* used fetchadd to atomically update the count */
319			if ((last.count & 15) < 5 && (ia64_fetchadd(1, &last.count, acq) & 15) < 5) {
320				last.time = current_jiffies + 5 * HZ;
321				printk(KERN_WARNING
322		       			"%s(%d): floating-point assist fault at ip %016lx, isr %016lx\n",
323		       			current->comm, task_pid_nr(current), regs->cr_iip + ia64_psr(regs)->ri, isr);
324			}
325		}
326	}
327
328	exception = fp_emulate(fp_fault, bundle, &regs->cr_ipsr, &regs->ar_fpsr, &isr, &regs->pr,
329			       &regs->cr_ifs, regs);
330	if (fp_fault) {
331		if (exception == 0) {
332			/* emulation was successful */
333			ia64_increment_ip(regs);
334		} else if (exception == -1) {
335			printk(KERN_ERR "handle_fpu_swa: fp_emulate() returned -1\n");
336			return -1;
337		} else {
338			/* is next instruction a trap? */
339			int si_code;
340
341			if (exception & 2) {
342				ia64_increment_ip(regs);
343			}
344			si_code = FPE_FLTUNK;	/* default code */
 
 
 
345			if (isr & 0x11) {
346				si_code = FPE_FLTINV;
347			} else if (isr & 0x22) {
348				/* denormal operand gets the same si_code as underflow 
349				* see arch/i386/kernel/traps.c:math_error()  */
350				si_code = FPE_FLTUND;
351			} else if (isr & 0x44) {
352				si_code = FPE_FLTDIV;
353			}
354			force_sig_fault(SIGFPE, si_code,
355					(void __user *) (regs->cr_iip + ia64_psr(regs)->ri),
356					0, __ISR_VALID, isr);
 
357		}
358	} else {
359		if (exception == -1) {
360			printk(KERN_ERR "handle_fpu_swa: fp_emulate() returned -1\n");
361			return -1;
362		} else if (exception != 0) {
363			/* raise exception */
364			int si_code;
365
366			si_code = FPE_FLTUNK;	/* default code */
 
367			if (isr & 0x880) {
368				si_code = FPE_FLTOVF;
369			} else if (isr & 0x1100) {
370				si_code = FPE_FLTUND;
371			} else if (isr & 0x2200) {
372				si_code = FPE_FLTRES;
373			}
374			force_sig_fault(SIGFPE, si_code,
375					(void __user *) (regs->cr_iip + ia64_psr(regs)->ri),
376					0, __ISR_VALID, isr);
 
377		}
378	}
379	return 0;
380}
381
382struct illegal_op_return {
383	unsigned long fkt, arg1, arg2, arg3;
384};
385
386struct illegal_op_return
387ia64_illegal_op_fault (unsigned long ec, long arg1, long arg2, long arg3,
388		       long arg4, long arg5, long arg6, long arg7,
389		       struct pt_regs regs)
390{
391	struct illegal_op_return rv;
 
392	char buf[128];
393
394#ifdef CONFIG_IA64_BRL_EMU
395	{
396		extern struct illegal_op_return ia64_emulate_brl (struct pt_regs *, unsigned long);
397
398		rv = ia64_emulate_brl(&regs, ec);
399		if (rv.fkt != (unsigned long) -1)
400			return rv;
401	}
402#endif
403
404	sprintf(buf, "IA-64 Illegal operation fault");
405	rv.fkt = 0;
406	if (die_if_kernel(buf, &regs, 0))
407		return rv;
408
409	force_sig_fault(SIGILL, ILL_ILLOPC,
410			(void __user *) (regs.cr_iip + ia64_psr(&regs)->ri),
411			0, 0, 0);
 
 
412	return rv;
413}
414
415void __kprobes
416ia64_fault (unsigned long vector, unsigned long isr, unsigned long ifa,
417	    unsigned long iim, unsigned long itir, long arg5, long arg6,
418	    long arg7, struct pt_regs regs)
419{
420	unsigned long code, error = isr, iip;
 
421	char buf[128];
422	int result, sig, si_code;
423	static const char *reason[] = {
424		"IA-64 Illegal Operation fault",
425		"IA-64 Privileged Operation fault",
426		"IA-64 Privileged Register fault",
427		"IA-64 Reserved Register/Field fault",
428		"Disabled Instruction Set Transition fault",
429		"Unknown fault 5", "Unknown fault 6", "Unknown fault 7", "Illegal Hazard fault",
430		"Unknown fault 9", "Unknown fault 10", "Unknown fault 11", "Unknown fault 12",
431		"Unknown fault 13", "Unknown fault 14", "Unknown fault 15"
432	};
433
434	if ((isr & IA64_ISR_NA) && ((isr & IA64_ISR_CODE_MASK) == IA64_ISR_CODE_LFETCH)) {
435		/*
436		 * This fault was due to lfetch.fault, set "ed" bit in the psr to cancel
437		 * the lfetch.
438		 */
439		ia64_psr(&regs)->ed = 1;
440		return;
441	}
442
443	iip = regs.cr_iip + ia64_psr(&regs)->ri;
444
445	switch (vector) {
446	      case 24: /* General Exception */
447		code = (isr >> 4) & 0xf;
448		sprintf(buf, "General Exception: %s%s", reason[code],
449			(code == 3) ? ((isr & (1UL << 37))
450				       ? " (RSE access)" : " (data access)") : "");
451		if (code == 8) {
452# ifdef CONFIG_IA64_PRINT_HAZARDS
453			printk("%s[%d]: possible hazard @ ip=%016lx (pr = %016lx)\n",
454			       current->comm, task_pid_nr(current),
455			       regs.cr_iip + ia64_psr(&regs)->ri, regs.pr);
456# endif
457			return;
458		}
459		break;
460
461	      case 25: /* Disabled FP-Register */
462		if (isr & 2) {
463			disabled_fph_fault(&regs);
464			return;
465		}
466		sprintf(buf, "Disabled FPL fault---not supposed to happen!");
467		break;
468
469	      case 26: /* NaT Consumption */
470		if (user_mode(&regs)) {
471			void __user *addr;
472
473			if (((isr >> 4) & 0xf) == 2) {
474				/* NaT page consumption */
475				sig = SIGSEGV;
476				code = SEGV_ACCERR;
477				addr = (void __user *) ifa;
478			} else {
479				/* register NaT consumption */
480				sig = SIGILL;
481				code = ILL_ILLOPN;
482				addr = (void __user *) (regs.cr_iip
483							+ ia64_psr(&regs)->ri);
484			}
485			force_sig_fault(sig, code, addr,
486					vector, __ISR_VALID, isr);
 
 
 
 
 
 
487			return;
488		} else if (ia64_done_with_exception(&regs))
489			return;
490		sprintf(buf, "NaT consumption");
491		break;
492
493	      case 31: /* Unsupported Data Reference */
494		if (user_mode(&regs)) {
495			force_sig_fault(SIGILL, ILL_ILLOPN, (void __user *) iip,
496					vector, __ISR_VALID, isr);
 
 
 
 
 
 
497			return;
498		}
499		sprintf(buf, "Unsupported data reference");
500		break;
501
502	      case 29: /* Debug */
503	      case 35: /* Taken Branch Trap */
504	      case 36: /* Single Step Trap */
505		if (fsys_mode(current, &regs)) {
506			extern char __kernel_syscall_via_break[];
507			/*
508			 * Got a trap in fsys-mode: Taken Branch Trap
509			 * and Single Step trap need special handling;
510			 * Debug trap is ignored (we disable it here
511			 * and re-enable it in the lower-privilege trap).
512			 */
513			if (unlikely(vector == 29)) {
514				set_thread_flag(TIF_DB_DISABLED);
515				ia64_psr(&regs)->db = 0;
516				ia64_psr(&regs)->lp = 1;
517				return;
518			}
519			/* re-do the system call via break 0x100000: */
520			regs.cr_iip = (unsigned long) __kernel_syscall_via_break;
521			ia64_psr(&regs)->ri = 0;
522			ia64_psr(&regs)->cpl = 3;
523			return;
524		}
525		switch (vector) {
526		      default:
527		      case 29:
528			si_code = TRAP_HWBKPT;
529#ifdef CONFIG_ITANIUM
530			/*
531			 * Erratum 10 (IFA may contain incorrect address) now has
532			 * "NoFix" status.  There are no plans for fixing this.
533			 */
534			if (ia64_psr(&regs)->is == 0)
535			  ifa = regs.cr_iip;
536#endif
537			break;
538		      case 35: si_code = TRAP_BRANCH; ifa = 0; break;
539		      case 36: si_code = TRAP_TRACE; ifa = 0; break;
540		}
541		if (notify_die(DIE_FAULT, "ia64_fault", &regs, vector, si_code, SIGTRAP)
542			       	== NOTIFY_STOP)
543			return;
544		force_sig_fault(SIGTRAP, si_code, (void __user *) ifa,
545				0, __ISR_VALID, isr);
 
 
 
 
 
546		return;
547
548	      case 32: /* fp fault */
549	      case 33: /* fp trap */
550		result = handle_fpu_swa((vector == 32) ? 1 : 0, &regs, isr);
551		if ((result < 0) || (current->thread.flags & IA64_THREAD_FPEMU_SIGFPE)) {
552			force_sig_fault(SIGFPE, FPE_FLTINV, (void __user *) iip,
553					0, __ISR_VALID, isr);
 
 
 
 
 
 
554		}
555		return;
556
557	      case 34:
558		if (isr & 0x2) {
559			/* Lower-Privilege Transfer Trap */
560
561			/* If we disabled debug traps during an fsyscall,
562			 * re-enable them here.
563			 */
564			if (test_thread_flag(TIF_DB_DISABLED)) {
565				clear_thread_flag(TIF_DB_DISABLED);
566				ia64_psr(&regs)->db = 1;
567			}
568
569			/*
570			 * Just clear PSR.lp and then return immediately:
571			 * all the interesting work (e.g., signal delivery)
572			 * is done in the kernel exit path.
573			 */
574			ia64_psr(&regs)->lp = 0;
575			return;
576		} else {
577			/* Unimplemented Instr. Address Trap */
578			if (user_mode(&regs)) {
579				force_sig_fault(SIGILL, ILL_BADIADDR,
580						(void __user *) iip,
581						0, 0, 0);
 
 
 
 
 
582				return;
583			}
584			sprintf(buf, "Unimplemented Instruction Address fault");
585		}
586		break;
587
588	      case 45:
589		printk(KERN_ERR "Unexpected IA-32 exception (Trap 45)\n");
590		printk(KERN_ERR "  iip - 0x%lx, ifa - 0x%lx, isr - 0x%lx\n",
591		       iip, ifa, isr);
592		force_sig(SIGSEGV);
593		return;
594
595	      case 46:
596		printk(KERN_ERR "Unexpected IA-32 intercept trap (Trap 46)\n");
597		printk(KERN_ERR "  iip - 0x%lx, ifa - 0x%lx, isr - 0x%lx, iim - 0x%lx\n",
598		       iip, ifa, isr, iim);
599		force_sig(SIGSEGV);
600		return;
601
602	      case 47:
603		sprintf(buf, "IA-32 Interruption Fault (int 0x%lx)", isr >> 16);
604		break;
605
606	      default:
607		sprintf(buf, "Fault %lu", vector);
608		break;
609	}
610	if (!die_if_kernel(buf, &regs, error))
611		force_sig(SIGILL);
612}
v3.1
 
  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.h>
 
 13#include <linux/tty.h>
 14#include <linux/vt_kern.h>		/* For unblank_screen() */
 15#include <linux/module.h>       /* for EXPORT_SYMBOL */
 
 16#include <linux/hardirq.h>
 17#include <linux/kprobes.h>
 18#include <linux/delay.h>		/* for ssleep() */
 19#include <linux/kdebug.h>
 
 20
 21#include <asm/fpswa.h>
 22#include <asm/intrinsics.h>
 23#include <asm/processor.h>
 24#include <asm/uaccess.h>
 
 25
 26fpswa_interface_t *fpswa_interface;
 27EXPORT_SYMBOL(fpswa_interface);
 28
 29void __init
 30trap_init (void)
 31{
 32	if (ia64_boot_param->fpswa)
 33		/* FPSWA fixup: make the interface pointer a kernel virtual address: */
 34		fpswa_interface = __va(ia64_boot_param->fpswa);
 35}
 36
 37int
 38die (const char *str, struct pt_regs *regs, long err)
 39{
 40	static struct {
 41		spinlock_t lock;
 42		u32 lock_owner;
 43		int lock_owner_depth;
 44	} die = {
 45		.lock =	__SPIN_LOCK_UNLOCKED(die.lock),
 46		.lock_owner = -1,
 47		.lock_owner_depth = 0
 48	};
 49	static int die_counter;
 50	int cpu = get_cpu();
 51
 52	if (die.lock_owner != cpu) {
 53		console_verbose();
 54		spin_lock_irq(&die.lock);
 55		die.lock_owner = cpu;
 56		die.lock_owner_depth = 0;
 57		bust_spinlocks(1);
 58	}
 59	put_cpu();
 60
 61	if (++die.lock_owner_depth < 3) {
 62		printk("%s[%d]: %s %ld [%d]\n",
 63		current->comm, task_pid_nr(current), str, err, ++die_counter);
 64		if (notify_die(DIE_OOPS, str, regs, err, 255, SIGSEGV)
 65	            != NOTIFY_STOP)
 66			show_regs(regs);
 67		else
 68			regs = NULL;
 69  	} else
 70		printk(KERN_ERR "Recursive die() failure, output suppressed\n");
 71
 72	bust_spinlocks(0);
 73	die.lock_owner = -1;
 74	add_taint(TAINT_DIE);
 75	spin_unlock_irq(&die.lock);
 76
 77	if (!regs)
 78		return 1;
 79
 80	if (panic_on_oops)
 81		panic("Fatal exception");
 82
 83  	do_exit(SIGSEGV);
 84	return 0;
 85}
 86
 87int
 88die_if_kernel (char *str, struct pt_regs *regs, long err)
 89{
 90	if (!user_mode(regs))
 91		return die(str, regs, err);
 92	return 0;
 93}
 94
 95void
 96__kprobes ia64_bad_break (unsigned long break_num, struct pt_regs *regs)
 97{
 98	siginfo_t siginfo;
 99	int sig, code;
100
101	/* SIGILL, SIGFPE, SIGSEGV, and SIGBUS want these field initialized: */
102	siginfo.si_addr = (void __user *) (regs->cr_iip + ia64_psr(regs)->ri);
103	siginfo.si_imm = break_num;
104	siginfo.si_flags = 0;		/* clear __ISR_VALID */
105	siginfo.si_isr = 0;
106
107	switch (break_num) {
108	      case 0: /* unknown error (used by GCC for __builtin_abort()) */
109		if (notify_die(DIE_BREAK, "break 0", regs, break_num, TRAP_BRKPT, SIGTRAP)
110			       	== NOTIFY_STOP)
111			return;
112		if (die_if_kernel("bugcheck!", regs, break_num))
113			return;
114		sig = SIGILL; code = ILL_ILLOPC;
115		break;
116
117	      case 1: /* integer divide by zero */
118		sig = SIGFPE; code = FPE_INTDIV;
119		break;
120
121	      case 2: /* integer overflow */
122		sig = SIGFPE; code = FPE_INTOVF;
123		break;
124
125	      case 3: /* range check/bounds check */
126		sig = SIGFPE; code = FPE_FLTSUB;
127		break;
128
129	      case 4: /* null pointer dereference */
130		sig = SIGSEGV; code = SEGV_MAPERR;
131		break;
132
133	      case 5: /* misaligned data */
134		sig = SIGSEGV; code = BUS_ADRALN;
135		break;
136
137	      case 6: /* decimal overflow */
138		sig = SIGFPE; code = __FPE_DECOVF;
139		break;
140
141	      case 7: /* decimal divide by zero */
142		sig = SIGFPE; code = __FPE_DECDIV;
143		break;
144
145	      case 8: /* packed decimal error */
146		sig = SIGFPE; code = __FPE_DECERR;
147		break;
148
149	      case 9: /* invalid ASCII digit */
150		sig = SIGFPE; code = __FPE_INVASC;
151		break;
152
153	      case 10: /* invalid decimal digit */
154		sig = SIGFPE; code = __FPE_INVDEC;
155		break;
156
157	      case 11: /* paragraph stack overflow */
158		sig = SIGSEGV; code = __SEGV_PSTKOVF;
159		break;
160
161	      case 0x3f000 ... 0x3ffff:	/* bundle-update in progress */
162		sig = SIGILL; code = __ILL_BNDMOD;
163		break;
164
165	      default:
166		if ((break_num < 0x40000 || break_num > 0x100000)
167		    && die_if_kernel("Bad break", regs, break_num))
168			return;
169
170		if (break_num < 0x80000) {
171			sig = SIGILL; code = __ILL_BREAK;
172		} else {
173			if (notify_die(DIE_BREAK, "bad break", regs, break_num, TRAP_BRKPT, SIGTRAP)
174					== NOTIFY_STOP)
175				return;
176			sig = SIGTRAP; code = TRAP_BRKPT;
177		}
178	}
179	siginfo.si_signo = sig;
180	siginfo.si_errno = 0;
181	siginfo.si_code = code;
182	force_sig_info(sig, &siginfo, current);
183}
184
185/*
186 * disabled_fph_fault() is called when a user-level process attempts to access f32..f127
187 * and it doesn't own the fp-high register partition.  When this happens, we save the
188 * current fph partition in the task_struct of the fpu-owner (if necessary) and then load
189 * the fp-high partition of the current task (if necessary).  Note that the kernel has
190 * access to fph by the time we get here, as the IVT's "Disabled FP-Register" handler takes
191 * care of clearing psr.dfh.
192 */
193static inline void
194disabled_fph_fault (struct pt_regs *regs)
195{
196	struct ia64_psr *psr = ia64_psr(regs);
197
198	/* first, grant user-level access to fph partition: */
199	psr->dfh = 0;
200
201	/*
202	 * Make sure that no other task gets in on this processor
203	 * while we're claiming the FPU
204	 */
205	preempt_disable();
206#ifndef CONFIG_SMP
207	{
208		struct task_struct *fpu_owner
209			= (struct task_struct *)ia64_get_kr(IA64_KR_FPU_OWNER);
210
211		if (ia64_is_local_fpu_owner(current)) {
212			preempt_enable_no_resched();
213			return;
214		}
215
216		if (fpu_owner)
217			ia64_flush_fph(fpu_owner);
218	}
219#endif /* !CONFIG_SMP */
220	ia64_set_local_fpu_owner(current);
221	if ((current->thread.flags & IA64_THREAD_FPH_VALID) != 0) {
222		__ia64_load_fpu(current->thread.fph);
223		psr->mfh = 0;
224	} else {
225		__ia64_init_fpu();
226		/*
227		 * Set mfh because the state in thread.fph does not match the state in
228		 * the fph partition.
229		 */
230		psr->mfh = 1;
231	}
232	preempt_enable_no_resched();
233}
234
235static inline int
236fp_emulate (int fp_fault, void *bundle, long *ipsr, long *fpsr, long *isr, long *pr, long *ifs,
237	    struct pt_regs *regs)
238{
239	fp_state_t fp_state;
240	fpswa_ret_t ret;
241
242	if (!fpswa_interface)
243		return -1;
244
245	memset(&fp_state, 0, sizeof(fp_state_t));
246
247	/*
248	 * compute fp_state.  only FP registers f6 - f11 are used by the
249	 * kernel, so set those bits in the mask and set the low volatile
250	 * pointer to point to these registers.
251	 */
252	fp_state.bitmask_low64 = 0xfc0;  /* bit6..bit11 */
253
254	fp_state.fp_state_low_volatile = (fp_state_low_volatile_t *) &regs->f6;
255	/*
256	 * unsigned long (*EFI_FPSWA) (
257	 *      unsigned long    trap_type,
258	 *	void             *Bundle,
259	 *	unsigned long    *pipsr,
260	 *	unsigned long    *pfsr,
261	 *	unsigned long    *pisr,
262	 *	unsigned long    *ppreds,
263	 *	unsigned long    *pifs,
264	 *	void             *fp_state);
265	 */
266	ret = (*fpswa_interface->fpswa)((unsigned long) fp_fault, bundle,
267					(unsigned long *) ipsr, (unsigned long *) fpsr,
268					(unsigned long *) isr, (unsigned long *) pr,
269					(unsigned long *) ifs, &fp_state);
270
271	return ret.status;
272}
273
274struct fpu_swa_msg {
275	unsigned long count;
276	unsigned long time;
277};
278static DEFINE_PER_CPU(struct fpu_swa_msg, cpulast);
279DECLARE_PER_CPU(struct fpu_swa_msg, cpulast);
280static struct fpu_swa_msg last __cacheline_aligned;
281
282
283/*
284 * Handle floating-point assist faults and traps.
285 */
286static int
287handle_fpu_swa (int fp_fault, struct pt_regs *regs, unsigned long isr)
288{
289	long exception, bundle[2];
290	unsigned long fault_ip;
291	struct siginfo siginfo;
292
293	fault_ip = regs->cr_iip;
294	if (!fp_fault && (ia64_psr(regs)->ri == 0))
295		fault_ip -= 16;
296	if (copy_from_user(bundle, (void __user *) fault_ip, sizeof(bundle)))
297		return -1;
298
299	if (!(current->thread.flags & IA64_THREAD_FPEMU_NOPRINT))  {
300		unsigned long count, current_jiffies = jiffies;
301		struct fpu_swa_msg *cp = &__get_cpu_var(cpulast);
302
303		if (unlikely(current_jiffies > cp->time))
304			cp->count = 0;
305		if (unlikely(cp->count < 5)) {
306			cp->count++;
307			cp->time = current_jiffies + 5 * HZ;
308
309			/* minimize races by grabbing a copy of count BEFORE checking last.time. */
310			count = last.count;
311			barrier();
312
313			/*
314			 * Lower 4 bits are used as a count. Upper bits are a sequence
315			 * number that is updated when count is reset. The cmpxchg will
316			 * fail is seqno has changed. This minimizes mutiple cpus
317			 * resetting the count.
318			 */
319			if (current_jiffies > last.time)
320				(void) cmpxchg_acq(&last.count, count, 16 + (count & ~15));
321
322			/* used fetchadd to atomically update the count */
323			if ((last.count & 15) < 5 && (ia64_fetchadd(1, &last.count, acq) & 15) < 5) {
324				last.time = current_jiffies + 5 * HZ;
325				printk(KERN_WARNING
326		       			"%s(%d): floating-point assist fault at ip %016lx, isr %016lx\n",
327		       			current->comm, task_pid_nr(current), regs->cr_iip + ia64_psr(regs)->ri, isr);
328			}
329		}
330	}
331
332	exception = fp_emulate(fp_fault, bundle, &regs->cr_ipsr, &regs->ar_fpsr, &isr, &regs->pr,
333			       &regs->cr_ifs, regs);
334	if (fp_fault) {
335		if (exception == 0) {
336			/* emulation was successful */
337			ia64_increment_ip(regs);
338		} else if (exception == -1) {
339			printk(KERN_ERR "handle_fpu_swa: fp_emulate() returned -1\n");
340			return -1;
341		} else {
342			/* is next instruction a trap? */
 
 
343			if (exception & 2) {
344				ia64_increment_ip(regs);
345			}
346			siginfo.si_signo = SIGFPE;
347			siginfo.si_errno = 0;
348			siginfo.si_code = __SI_FAULT;	/* default code */
349			siginfo.si_addr = (void __user *) (regs->cr_iip + ia64_psr(regs)->ri);
350			if (isr & 0x11) {
351				siginfo.si_code = FPE_FLTINV;
352			} else if (isr & 0x22) {
353				/* denormal operand gets the same si_code as underflow 
354				* see arch/i386/kernel/traps.c:math_error()  */
355				siginfo.si_code = FPE_FLTUND;
356			} else if (isr & 0x44) {
357				siginfo.si_code = FPE_FLTDIV;
358			}
359			siginfo.si_isr = isr;
360			siginfo.si_flags = __ISR_VALID;
361			siginfo.si_imm = 0;
362			force_sig_info(SIGFPE, &siginfo, current);
363		}
364	} else {
365		if (exception == -1) {
366			printk(KERN_ERR "handle_fpu_swa: fp_emulate() returned -1\n");
367			return -1;
368		} else if (exception != 0) {
369			/* raise exception */
370			siginfo.si_signo = SIGFPE;
371			siginfo.si_errno = 0;
372			siginfo.si_code = __SI_FAULT;	/* default code */
373			siginfo.si_addr = (void __user *) (regs->cr_iip + ia64_psr(regs)->ri);
374			if (isr & 0x880) {
375				siginfo.si_code = FPE_FLTOVF;
376			} else if (isr & 0x1100) {
377				siginfo.si_code = FPE_FLTUND;
378			} else if (isr & 0x2200) {
379				siginfo.si_code = FPE_FLTRES;
380			}
381			siginfo.si_isr = isr;
382			siginfo.si_flags = __ISR_VALID;
383			siginfo.si_imm = 0;
384			force_sig_info(SIGFPE, &siginfo, current);
385		}
386	}
387	return 0;
388}
389
390struct illegal_op_return {
391	unsigned long fkt, arg1, arg2, arg3;
392};
393
394struct illegal_op_return
395ia64_illegal_op_fault (unsigned long ec, long arg1, long arg2, long arg3,
396		       long arg4, long arg5, long arg6, long arg7,
397		       struct pt_regs regs)
398{
399	struct illegal_op_return rv;
400	struct siginfo si;
401	char buf[128];
402
403#ifdef CONFIG_IA64_BRL_EMU
404	{
405		extern struct illegal_op_return ia64_emulate_brl (struct pt_regs *, unsigned long);
406
407		rv = ia64_emulate_brl(&regs, ec);
408		if (rv.fkt != (unsigned long) -1)
409			return rv;
410	}
411#endif
412
413	sprintf(buf, "IA-64 Illegal operation fault");
414	rv.fkt = 0;
415	if (die_if_kernel(buf, &regs, 0))
416		return rv;
417
418	memset(&si, 0, sizeof(si));
419	si.si_signo = SIGILL;
420	si.si_code = ILL_ILLOPC;
421	si.si_addr = (void __user *) (regs.cr_iip + ia64_psr(&regs)->ri);
422	force_sig_info(SIGILL, &si, current);
423	return rv;
424}
425
426void __kprobes
427ia64_fault (unsigned long vector, unsigned long isr, unsigned long ifa,
428	    unsigned long iim, unsigned long itir, long arg5, long arg6,
429	    long arg7, struct pt_regs regs)
430{
431	unsigned long code, error = isr, iip;
432	struct siginfo siginfo;
433	char buf[128];
434	int result, sig;
435	static const char *reason[] = {
436		"IA-64 Illegal Operation fault",
437		"IA-64 Privileged Operation fault",
438		"IA-64 Privileged Register fault",
439		"IA-64 Reserved Register/Field fault",
440		"Disabled Instruction Set Transition fault",
441		"Unknown fault 5", "Unknown fault 6", "Unknown fault 7", "Illegal Hazard fault",
442		"Unknown fault 9", "Unknown fault 10", "Unknown fault 11", "Unknown fault 12",
443		"Unknown fault 13", "Unknown fault 14", "Unknown fault 15"
444	};
445
446	if ((isr & IA64_ISR_NA) && ((isr & IA64_ISR_CODE_MASK) == IA64_ISR_CODE_LFETCH)) {
447		/*
448		 * This fault was due to lfetch.fault, set "ed" bit in the psr to cancel
449		 * the lfetch.
450		 */
451		ia64_psr(&regs)->ed = 1;
452		return;
453	}
454
455	iip = regs.cr_iip + ia64_psr(&regs)->ri;
456
457	switch (vector) {
458	      case 24: /* General Exception */
459		code = (isr >> 4) & 0xf;
460		sprintf(buf, "General Exception: %s%s", reason[code],
461			(code == 3) ? ((isr & (1UL << 37))
462				       ? " (RSE access)" : " (data access)") : "");
463		if (code == 8) {
464# ifdef CONFIG_IA64_PRINT_HAZARDS
465			printk("%s[%d]: possible hazard @ ip=%016lx (pr = %016lx)\n",
466			       current->comm, task_pid_nr(current),
467			       regs.cr_iip + ia64_psr(&regs)->ri, regs.pr);
468# endif
469			return;
470		}
471		break;
472
473	      case 25: /* Disabled FP-Register */
474		if (isr & 2) {
475			disabled_fph_fault(&regs);
476			return;
477		}
478		sprintf(buf, "Disabled FPL fault---not supposed to happen!");
479		break;
480
481	      case 26: /* NaT Consumption */
482		if (user_mode(&regs)) {
483			void __user *addr;
484
485			if (((isr >> 4) & 0xf) == 2) {
486				/* NaT page consumption */
487				sig = SIGSEGV;
488				code = SEGV_ACCERR;
489				addr = (void __user *) ifa;
490			} else {
491				/* register NaT consumption */
492				sig = SIGILL;
493				code = ILL_ILLOPN;
494				addr = (void __user *) (regs.cr_iip
495							+ ia64_psr(&regs)->ri);
496			}
497			siginfo.si_signo = sig;
498			siginfo.si_code = code;
499			siginfo.si_errno = 0;
500			siginfo.si_addr = addr;
501			siginfo.si_imm = vector;
502			siginfo.si_flags = __ISR_VALID;
503			siginfo.si_isr = isr;
504			force_sig_info(sig, &siginfo, current);
505			return;
506		} else if (ia64_done_with_exception(&regs))
507			return;
508		sprintf(buf, "NaT consumption");
509		break;
510
511	      case 31: /* Unsupported Data Reference */
512		if (user_mode(&regs)) {
513			siginfo.si_signo = SIGILL;
514			siginfo.si_code = ILL_ILLOPN;
515			siginfo.si_errno = 0;
516			siginfo.si_addr = (void __user *) iip;
517			siginfo.si_imm = vector;
518			siginfo.si_flags = __ISR_VALID;
519			siginfo.si_isr = isr;
520			force_sig_info(SIGILL, &siginfo, current);
521			return;
522		}
523		sprintf(buf, "Unsupported data reference");
524		break;
525
526	      case 29: /* Debug */
527	      case 35: /* Taken Branch Trap */
528	      case 36: /* Single Step Trap */
529		if (fsys_mode(current, &regs)) {
530			extern char __kernel_syscall_via_break[];
531			/*
532			 * Got a trap in fsys-mode: Taken Branch Trap
533			 * and Single Step trap need special handling;
534			 * Debug trap is ignored (we disable it here
535			 * and re-enable it in the lower-privilege trap).
536			 */
537			if (unlikely(vector == 29)) {
538				set_thread_flag(TIF_DB_DISABLED);
539				ia64_psr(&regs)->db = 0;
540				ia64_psr(&regs)->lp = 1;
541				return;
542			}
543			/* re-do the system call via break 0x100000: */
544			regs.cr_iip = (unsigned long) __kernel_syscall_via_break;
545			ia64_psr(&regs)->ri = 0;
546			ia64_psr(&regs)->cpl = 3;
547			return;
548		}
549		switch (vector) {
 
550		      case 29:
551			siginfo.si_code = TRAP_HWBKPT;
552#ifdef CONFIG_ITANIUM
553			/*
554			 * Erratum 10 (IFA may contain incorrect address) now has
555			 * "NoFix" status.  There are no plans for fixing this.
556			 */
557			if (ia64_psr(&regs)->is == 0)
558			  ifa = regs.cr_iip;
559#endif
560			break;
561		      case 35: siginfo.si_code = TRAP_BRANCH; ifa = 0; break;
562		      case 36: siginfo.si_code = TRAP_TRACE; ifa = 0; break;
563		}
564		if (notify_die(DIE_FAULT, "ia64_fault", &regs, vector, siginfo.si_code, SIGTRAP)
565			       	== NOTIFY_STOP)
566			return;
567		siginfo.si_signo = SIGTRAP;
568		siginfo.si_errno = 0;
569		siginfo.si_addr  = (void __user *) ifa;
570		siginfo.si_imm   = 0;
571		siginfo.si_flags = __ISR_VALID;
572		siginfo.si_isr   = isr;
573		force_sig_info(SIGTRAP, &siginfo, current);
574		return;
575
576	      case 32: /* fp fault */
577	      case 33: /* fp trap */
578		result = handle_fpu_swa((vector == 32) ? 1 : 0, &regs, isr);
579		if ((result < 0) || (current->thread.flags & IA64_THREAD_FPEMU_SIGFPE)) {
580			siginfo.si_signo = SIGFPE;
581			siginfo.si_errno = 0;
582			siginfo.si_code = FPE_FLTINV;
583			siginfo.si_addr = (void __user *) iip;
584			siginfo.si_flags = __ISR_VALID;
585			siginfo.si_isr = isr;
586			siginfo.si_imm = 0;
587			force_sig_info(SIGFPE, &siginfo, current);
588		}
589		return;
590
591	      case 34:
592		if (isr & 0x2) {
593			/* Lower-Privilege Transfer Trap */
594
595			/* If we disabled debug traps during an fsyscall,
596			 * re-enable them here.
597			 */
598			if (test_thread_flag(TIF_DB_DISABLED)) {
599				clear_thread_flag(TIF_DB_DISABLED);
600				ia64_psr(&regs)->db = 1;
601			}
602
603			/*
604			 * Just clear PSR.lp and then return immediately:
605			 * all the interesting work (e.g., signal delivery)
606			 * is done in the kernel exit path.
607			 */
608			ia64_psr(&regs)->lp = 0;
609			return;
610		} else {
611			/* Unimplemented Instr. Address Trap */
612			if (user_mode(&regs)) {
613				siginfo.si_signo = SIGILL;
614				siginfo.si_code = ILL_BADIADDR;
615				siginfo.si_errno = 0;
616				siginfo.si_flags = 0;
617				siginfo.si_isr = 0;
618				siginfo.si_imm = 0;
619				siginfo.si_addr = (void __user *) iip;
620				force_sig_info(SIGILL, &siginfo, current);
621				return;
622			}
623			sprintf(buf, "Unimplemented Instruction Address fault");
624		}
625		break;
626
627	      case 45:
628		printk(KERN_ERR "Unexpected IA-32 exception (Trap 45)\n");
629		printk(KERN_ERR "  iip - 0x%lx, ifa - 0x%lx, isr - 0x%lx\n",
630		       iip, ifa, isr);
631		force_sig(SIGSEGV, current);
632		break;
633
634	      case 46:
635		printk(KERN_ERR "Unexpected IA-32 intercept trap (Trap 46)\n");
636		printk(KERN_ERR "  iip - 0x%lx, ifa - 0x%lx, isr - 0x%lx, iim - 0x%lx\n",
637		       iip, ifa, isr, iim);
638		force_sig(SIGSEGV, current);
639		return;
640
641	      case 47:
642		sprintf(buf, "IA-32 Interruption Fault (int 0x%lx)", isr >> 16);
643		break;
644
645	      default:
646		sprintf(buf, "Fault %lu", vector);
647		break;
648	}
649	if (!die_if_kernel(buf, &regs, error))
650		force_sig(SIGILL, current);
651}