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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}
v4.6
  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#include <asm/setup.h>
 26
 27fpswa_interface_t *fpswa_interface;
 28EXPORT_SYMBOL(fpswa_interface);
 29
 30void __init
 31trap_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
 38int
 39die (const char *str, struct pt_regs *regs, long err)
 40{
 41	static struct {
 42		spinlock_t lock;
 43		u32 lock_owner;
 44		int lock_owner_depth;
 45	} die = {
 46		.lock =	__SPIN_LOCK_UNLOCKED(die.lock),
 47		.lock_owner = -1,
 48		.lock_owner_depth = 0
 49	};
 50	static int die_counter;
 51	int cpu = get_cpu();
 52
 53	if (die.lock_owner != cpu) {
 54		console_verbose();
 55		spin_lock_irq(&die.lock);
 56		die.lock_owner = cpu;
 57		die.lock_owner_depth = 0;
 58		bust_spinlocks(1);
 59	}
 60	put_cpu();
 61
 62	if (++die.lock_owner_depth < 3) {
 63		printk("%s[%d]: %s %ld [%d]\n",
 64		current->comm, task_pid_nr(current), str, err, ++die_counter);
 65		if (notify_die(DIE_OOPS, str, regs, err, 255, SIGSEGV)
 66	            != NOTIFY_STOP)
 67			show_regs(regs);
 68		else
 69			regs = NULL;
 70  	} else
 71		printk(KERN_ERR "Recursive die() failure, output suppressed\n");
 72
 73	bust_spinlocks(0);
 74	die.lock_owner = -1;
 75	add_taint(TAINT_DIE, LOCKDEP_NOW_UNRELIABLE);
 76	spin_unlock_irq(&die.lock);
 77
 78	if (!regs)
 79		return 1;
 80
 81	if (panic_on_oops)
 82		panic("Fatal exception");
 83
 84  	do_exit(SIGSEGV);
 85	return 0;
 86}
 87
 88int
 89die_if_kernel (char *str, struct pt_regs *regs, long err)
 90{
 91	if (!user_mode(regs))
 92		return die(str, regs, err);
 93	return 0;
 94}
 95
 96void
 97__kprobes ia64_bad_break (unsigned long break_num, struct pt_regs *regs)
 98{
 99	siginfo_t siginfo;
100	int sig, code;
101
102	/* SIGILL, SIGFPE, SIGSEGV, and SIGBUS want these field initialized: */
103	siginfo.si_addr = (void __user *) (regs->cr_iip + ia64_psr(regs)->ri);
104	siginfo.si_imm = break_num;
105	siginfo.si_flags = 0;		/* clear __ISR_VALID */
106	siginfo.si_isr = 0;
107
108	switch (break_num) {
109	      case 0: /* unknown error (used by GCC for __builtin_abort()) */
110		if (notify_die(DIE_BREAK, "break 0", regs, break_num, TRAP_BRKPT, SIGTRAP)
111			       	== NOTIFY_STOP)
112			return;
113		if (die_if_kernel("bugcheck!", regs, break_num))
114			return;
115		sig = SIGILL; code = ILL_ILLOPC;
116		break;
117
118	      case 1: /* integer divide by zero */
119		sig = SIGFPE; code = FPE_INTDIV;
120		break;
121
122	      case 2: /* integer overflow */
123		sig = SIGFPE; code = FPE_INTOVF;
124		break;
125
126	      case 3: /* range check/bounds check */
127		sig = SIGFPE; code = FPE_FLTSUB;
128		break;
129
130	      case 4: /* null pointer dereference */
131		sig = SIGSEGV; code = SEGV_MAPERR;
132		break;
133
134	      case 5: /* misaligned data */
135		sig = SIGSEGV; code = BUS_ADRALN;
136		break;
137
138	      case 6: /* decimal overflow */
139		sig = SIGFPE; code = __FPE_DECOVF;
140		break;
141
142	      case 7: /* decimal divide by zero */
143		sig = SIGFPE; code = __FPE_DECDIV;
144		break;
145
146	      case 8: /* packed decimal error */
147		sig = SIGFPE; code = __FPE_DECERR;
148		break;
149
150	      case 9: /* invalid ASCII digit */
151		sig = SIGFPE; code = __FPE_INVASC;
152		break;
153
154	      case 10: /* invalid decimal digit */
155		sig = SIGFPE; code = __FPE_INVDEC;
156		break;
157
158	      case 11: /* paragraph stack overflow */
159		sig = SIGSEGV; code = __SEGV_PSTKOVF;
160		break;
161
162	      case 0x3f000 ... 0x3ffff:	/* bundle-update in progress */
163		sig = SIGILL; code = __ILL_BNDMOD;
164		break;
165
166	      default:
167		if ((break_num < 0x40000 || break_num > 0x100000)
168		    && die_if_kernel("Bad break", regs, break_num))
169			return;
170
171		if (break_num < 0x80000) {
172			sig = SIGILL; code = __ILL_BREAK;
173		} else {
174			if (notify_die(DIE_BREAK, "bad break", regs, break_num, TRAP_BRKPT, SIGTRAP)
175					== NOTIFY_STOP)
176				return;
177			sig = SIGTRAP; code = TRAP_BRKPT;
178		}
179	}
180	siginfo.si_signo = sig;
181	siginfo.si_errno = 0;
182	siginfo.si_code = code;
183	force_sig_info(sig, &siginfo, current);
184}
185
186/*
187 * disabled_fph_fault() is called when a user-level process attempts to access f32..f127
188 * and it doesn't own the fp-high register partition.  When this happens, we save the
189 * current fph partition in the task_struct of the fpu-owner (if necessary) and then load
190 * the fp-high partition of the current task (if necessary).  Note that the kernel has
191 * access to fph by the time we get here, as the IVT's "Disabled FP-Register" handler takes
192 * care of clearing psr.dfh.
193 */
194static inline void
195disabled_fph_fault (struct pt_regs *regs)
196{
197	struct ia64_psr *psr = ia64_psr(regs);
198
199	/* first, grant user-level access to fph partition: */
200	psr->dfh = 0;
201
202	/*
203	 * Make sure that no other task gets in on this processor
204	 * while we're claiming the FPU
205	 */
206	preempt_disable();
207#ifndef CONFIG_SMP
208	{
209		struct task_struct *fpu_owner
210			= (struct task_struct *)ia64_get_kr(IA64_KR_FPU_OWNER);
211
212		if (ia64_is_local_fpu_owner(current)) {
213			preempt_enable_no_resched();
214			return;
215		}
216
217		if (fpu_owner)
218			ia64_flush_fph(fpu_owner);
219	}
220#endif /* !CONFIG_SMP */
221	ia64_set_local_fpu_owner(current);
222	if ((current->thread.flags & IA64_THREAD_FPH_VALID) != 0) {
223		__ia64_load_fpu(current->thread.fph);
224		psr->mfh = 0;
225	} else {
226		__ia64_init_fpu();
227		/*
228		 * Set mfh because the state in thread.fph does not match the state in
229		 * the fph partition.
230		 */
231		psr->mfh = 1;
232	}
233	preempt_enable_no_resched();
234}
235
236static inline int
237fp_emulate (int fp_fault, void *bundle, long *ipsr, long *fpsr, long *isr, long *pr, long *ifs,
238	    struct pt_regs *regs)
239{
240	fp_state_t fp_state;
241	fpswa_ret_t ret;
242
243	if (!fpswa_interface)
244		return -1;
245
246	memset(&fp_state, 0, sizeof(fp_state_t));
247
248	/*
249	 * compute fp_state.  only FP registers f6 - f11 are used by the
250	 * kernel, so set those bits in the mask and set the low volatile
251	 * pointer to point to these registers.
252	 */
253	fp_state.bitmask_low64 = 0xfc0;  /* bit6..bit11 */
254
255	fp_state.fp_state_low_volatile = (fp_state_low_volatile_t *) &regs->f6;
256	/*
257	 * unsigned long (*EFI_FPSWA) (
258	 *      unsigned long    trap_type,
259	 *	void             *Bundle,
260	 *	unsigned long    *pipsr,
261	 *	unsigned long    *pfsr,
262	 *	unsigned long    *pisr,
263	 *	unsigned long    *ppreds,
264	 *	unsigned long    *pifs,
265	 *	void             *fp_state);
266	 */
267	ret = (*fpswa_interface->fpswa)((unsigned long) fp_fault, bundle,
268					(unsigned long *) ipsr, (unsigned long *) fpsr,
269					(unsigned long *) isr, (unsigned long *) pr,
270					(unsigned long *) ifs, &fp_state);
271
272	return ret.status;
273}
274
275struct fpu_swa_msg {
276	unsigned long count;
277	unsigned long time;
278};
279static DEFINE_PER_CPU(struct fpu_swa_msg, cpulast);
280DECLARE_PER_CPU(struct fpu_swa_msg, cpulast);
281static struct fpu_swa_msg last __cacheline_aligned;
282
283
284/*
285 * Handle floating-point assist faults and traps.
286 */
287static int
288handle_fpu_swa (int fp_fault, struct pt_regs *regs, unsigned long isr)
289{
290	long exception, bundle[2];
291	unsigned long fault_ip;
292	struct siginfo siginfo;
293
294	fault_ip = regs->cr_iip;
295	if (!fp_fault && (ia64_psr(regs)->ri == 0))
296		fault_ip -= 16;
297	if (copy_from_user(bundle, (void __user *) fault_ip, sizeof(bundle)))
298		return -1;
299
300	if (!(current->thread.flags & IA64_THREAD_FPEMU_NOPRINT))  {
301		unsigned long count, current_jiffies = jiffies;
302		struct fpu_swa_msg *cp = this_cpu_ptr(&cpulast);
303
304		if (unlikely(current_jiffies > cp->time))
305			cp->count = 0;
306		if (unlikely(cp->count < 5)) {
307			cp->count++;
308			cp->time = current_jiffies + 5 * HZ;
309
310			/* minimize races by grabbing a copy of count BEFORE checking last.time. */
311			count = last.count;
312			barrier();
313
314			/*
315			 * Lower 4 bits are used as a count. Upper bits are a sequence
316			 * number that is updated when count is reset. The cmpxchg will
317			 * fail is seqno has changed. This minimizes mutiple cpus
318			 * resetting the count.
319			 */
320			if (current_jiffies > last.time)
321				(void) cmpxchg_acq(&last.count, count, 16 + (count & ~15));
322
323			/* used fetchadd to atomically update the count */
324			if ((last.count & 15) < 5 && (ia64_fetchadd(1, &last.count, acq) & 15) < 5) {
325				last.time = current_jiffies + 5 * HZ;
326				printk(KERN_WARNING
327		       			"%s(%d): floating-point assist fault at ip %016lx, isr %016lx\n",
328		       			current->comm, task_pid_nr(current), regs->cr_iip + ia64_psr(regs)->ri, isr);
329			}
330		}
331	}
332
333	exception = fp_emulate(fp_fault, bundle, &regs->cr_ipsr, &regs->ar_fpsr, &isr, &regs->pr,
334			       &regs->cr_ifs, regs);
335	if (fp_fault) {
336		if (exception == 0) {
337			/* emulation was successful */
338			ia64_increment_ip(regs);
339		} else if (exception == -1) {
340			printk(KERN_ERR "handle_fpu_swa: fp_emulate() returned -1\n");
341			return -1;
342		} else {
343			/* is next instruction a trap? */
344			if (exception & 2) {
345				ia64_increment_ip(regs);
346			}
347			siginfo.si_signo = SIGFPE;
348			siginfo.si_errno = 0;
349			siginfo.si_code = __SI_FAULT;	/* default code */
350			siginfo.si_addr = (void __user *) (regs->cr_iip + ia64_psr(regs)->ri);
351			if (isr & 0x11) {
352				siginfo.si_code = FPE_FLTINV;
353			} else if (isr & 0x22) {
354				/* denormal operand gets the same si_code as underflow 
355				* see arch/i386/kernel/traps.c:math_error()  */
356				siginfo.si_code = FPE_FLTUND;
357			} else if (isr & 0x44) {
358				siginfo.si_code = FPE_FLTDIV;
359			}
360			siginfo.si_isr = isr;
361			siginfo.si_flags = __ISR_VALID;
362			siginfo.si_imm = 0;
363			force_sig_info(SIGFPE, &siginfo, current);
364		}
365	} else {
366		if (exception == -1) {
367			printk(KERN_ERR "handle_fpu_swa: fp_emulate() returned -1\n");
368			return -1;
369		} else if (exception != 0) {
370			/* raise exception */
371			siginfo.si_signo = SIGFPE;
372			siginfo.si_errno = 0;
373			siginfo.si_code = __SI_FAULT;	/* default code */
374			siginfo.si_addr = (void __user *) (regs->cr_iip + ia64_psr(regs)->ri);
375			if (isr & 0x880) {
376				siginfo.si_code = FPE_FLTOVF;
377			} else if (isr & 0x1100) {
378				siginfo.si_code = FPE_FLTUND;
379			} else if (isr & 0x2200) {
380				siginfo.si_code = FPE_FLTRES;
381			}
382			siginfo.si_isr = isr;
383			siginfo.si_flags = __ISR_VALID;
384			siginfo.si_imm = 0;
385			force_sig_info(SIGFPE, &siginfo, current);
386		}
387	}
388	return 0;
389}
390
391struct illegal_op_return {
392	unsigned long fkt, arg1, arg2, arg3;
393};
394
395struct illegal_op_return
396ia64_illegal_op_fault (unsigned long ec, long arg1, long arg2, long arg3,
397		       long arg4, long arg5, long arg6, long arg7,
398		       struct pt_regs regs)
399{
400	struct illegal_op_return rv;
401	struct siginfo si;
402	char buf[128];
403
404#ifdef CONFIG_IA64_BRL_EMU
405	{
406		extern struct illegal_op_return ia64_emulate_brl (struct pt_regs *, unsigned long);
407
408		rv = ia64_emulate_brl(&regs, ec);
409		if (rv.fkt != (unsigned long) -1)
410			return rv;
411	}
412#endif
413
414	sprintf(buf, "IA-64 Illegal operation fault");
415	rv.fkt = 0;
416	if (die_if_kernel(buf, &regs, 0))
417		return rv;
418
419	memset(&si, 0, sizeof(si));
420	si.si_signo = SIGILL;
421	si.si_code = ILL_ILLOPC;
422	si.si_addr = (void __user *) (regs.cr_iip + ia64_psr(&regs)->ri);
423	force_sig_info(SIGILL, &si, current);
424	return rv;
425}
426
427void __kprobes
428ia64_fault (unsigned long vector, unsigned long isr, unsigned long ifa,
429	    unsigned long iim, unsigned long itir, long arg5, long arg6,
430	    long arg7, struct pt_regs regs)
431{
432	unsigned long code, error = isr, iip;
433	struct siginfo siginfo;
434	char buf[128];
435	int result, sig;
436	static const char *reason[] = {
437		"IA-64 Illegal Operation fault",
438		"IA-64 Privileged Operation fault",
439		"IA-64 Privileged Register fault",
440		"IA-64 Reserved Register/Field fault",
441		"Disabled Instruction Set Transition fault",
442		"Unknown fault 5", "Unknown fault 6", "Unknown fault 7", "Illegal Hazard fault",
443		"Unknown fault 9", "Unknown fault 10", "Unknown fault 11", "Unknown fault 12",
444		"Unknown fault 13", "Unknown fault 14", "Unknown fault 15"
445	};
446
447	if ((isr & IA64_ISR_NA) && ((isr & IA64_ISR_CODE_MASK) == IA64_ISR_CODE_LFETCH)) {
448		/*
449		 * This fault was due to lfetch.fault, set "ed" bit in the psr to cancel
450		 * the lfetch.
451		 */
452		ia64_psr(&regs)->ed = 1;
453		return;
454	}
455
456	iip = regs.cr_iip + ia64_psr(&regs)->ri;
457
458	switch (vector) {
459	      case 24: /* General Exception */
460		code = (isr >> 4) & 0xf;
461		sprintf(buf, "General Exception: %s%s", reason[code],
462			(code == 3) ? ((isr & (1UL << 37))
463				       ? " (RSE access)" : " (data access)") : "");
464		if (code == 8) {
465# ifdef CONFIG_IA64_PRINT_HAZARDS
466			printk("%s[%d]: possible hazard @ ip=%016lx (pr = %016lx)\n",
467			       current->comm, task_pid_nr(current),
468			       regs.cr_iip + ia64_psr(&regs)->ri, regs.pr);
469# endif
470			return;
471		}
472		break;
473
474	      case 25: /* Disabled FP-Register */
475		if (isr & 2) {
476			disabled_fph_fault(&regs);
477			return;
478		}
479		sprintf(buf, "Disabled FPL fault---not supposed to happen!");
480		break;
481
482	      case 26: /* NaT Consumption */
483		if (user_mode(&regs)) {
484			void __user *addr;
485
486			if (((isr >> 4) & 0xf) == 2) {
487				/* NaT page consumption */
488				sig = SIGSEGV;
489				code = SEGV_ACCERR;
490				addr = (void __user *) ifa;
491			} else {
492				/* register NaT consumption */
493				sig = SIGILL;
494				code = ILL_ILLOPN;
495				addr = (void __user *) (regs.cr_iip
496							+ ia64_psr(&regs)->ri);
497			}
498			siginfo.si_signo = sig;
499			siginfo.si_code = code;
500			siginfo.si_errno = 0;
501			siginfo.si_addr = addr;
502			siginfo.si_imm = vector;
503			siginfo.si_flags = __ISR_VALID;
504			siginfo.si_isr = isr;
505			force_sig_info(sig, &siginfo, current);
506			return;
507		} else if (ia64_done_with_exception(&regs))
508			return;
509		sprintf(buf, "NaT consumption");
510		break;
511
512	      case 31: /* Unsupported Data Reference */
513		if (user_mode(&regs)) {
514			siginfo.si_signo = SIGILL;
515			siginfo.si_code = ILL_ILLOPN;
516			siginfo.si_errno = 0;
517			siginfo.si_addr = (void __user *) iip;
518			siginfo.si_imm = vector;
519			siginfo.si_flags = __ISR_VALID;
520			siginfo.si_isr = isr;
521			force_sig_info(SIGILL, &siginfo, current);
522			return;
523		}
524		sprintf(buf, "Unsupported data reference");
525		break;
526
527	      case 29: /* Debug */
528	      case 35: /* Taken Branch Trap */
529	      case 36: /* Single Step Trap */
530		if (fsys_mode(current, &regs)) {
531			extern char __kernel_syscall_via_break[];
532			/*
533			 * Got a trap in fsys-mode: Taken Branch Trap
534			 * and Single Step trap need special handling;
535			 * Debug trap is ignored (we disable it here
536			 * and re-enable it in the lower-privilege trap).
537			 */
538			if (unlikely(vector == 29)) {
539				set_thread_flag(TIF_DB_DISABLED);
540				ia64_psr(&regs)->db = 0;
541				ia64_psr(&regs)->lp = 1;
542				return;
543			}
544			/* re-do the system call via break 0x100000: */
545			regs.cr_iip = (unsigned long) __kernel_syscall_via_break;
546			ia64_psr(&regs)->ri = 0;
547			ia64_psr(&regs)->cpl = 3;
548			return;
549		}
550		switch (vector) {
551		      case 29:
552			siginfo.si_code = TRAP_HWBKPT;
553#ifdef CONFIG_ITANIUM
554			/*
555			 * Erratum 10 (IFA may contain incorrect address) now has
556			 * "NoFix" status.  There are no plans for fixing this.
557			 */
558			if (ia64_psr(&regs)->is == 0)
559			  ifa = regs.cr_iip;
560#endif
561			break;
562		      case 35: siginfo.si_code = TRAP_BRANCH; ifa = 0; break;
563		      case 36: siginfo.si_code = TRAP_TRACE; ifa = 0; break;
564		}
565		if (notify_die(DIE_FAULT, "ia64_fault", &regs, vector, siginfo.si_code, SIGTRAP)
566			       	== NOTIFY_STOP)
567			return;
568		siginfo.si_signo = SIGTRAP;
569		siginfo.si_errno = 0;
570		siginfo.si_addr  = (void __user *) ifa;
571		siginfo.si_imm   = 0;
572		siginfo.si_flags = __ISR_VALID;
573		siginfo.si_isr   = isr;
574		force_sig_info(SIGTRAP, &siginfo, current);
575		return;
576
577	      case 32: /* fp fault */
578	      case 33: /* fp trap */
579		result = handle_fpu_swa((vector == 32) ? 1 : 0, &regs, isr);
580		if ((result < 0) || (current->thread.flags & IA64_THREAD_FPEMU_SIGFPE)) {
581			siginfo.si_signo = SIGFPE;
582			siginfo.si_errno = 0;
583			siginfo.si_code = FPE_FLTINV;
584			siginfo.si_addr = (void __user *) iip;
585			siginfo.si_flags = __ISR_VALID;
586			siginfo.si_isr = isr;
587			siginfo.si_imm = 0;
588			force_sig_info(SIGFPE, &siginfo, current);
589		}
590		return;
591
592	      case 34:
593		if (isr & 0x2) {
594			/* Lower-Privilege Transfer Trap */
595
596			/* If we disabled debug traps during an fsyscall,
597			 * re-enable them here.
598			 */
599			if (test_thread_flag(TIF_DB_DISABLED)) {
600				clear_thread_flag(TIF_DB_DISABLED);
601				ia64_psr(&regs)->db = 1;
602			}
603
604			/*
605			 * Just clear PSR.lp and then return immediately:
606			 * all the interesting work (e.g., signal delivery)
607			 * is done in the kernel exit path.
608			 */
609			ia64_psr(&regs)->lp = 0;
610			return;
611		} else {
612			/* Unimplemented Instr. Address Trap */
613			if (user_mode(&regs)) {
614				siginfo.si_signo = SIGILL;
615				siginfo.si_code = ILL_BADIADDR;
616				siginfo.si_errno = 0;
617				siginfo.si_flags = 0;
618				siginfo.si_isr = 0;
619				siginfo.si_imm = 0;
620				siginfo.si_addr = (void __user *) iip;
621				force_sig_info(SIGILL, &siginfo, current);
622				return;
623			}
624			sprintf(buf, "Unimplemented Instruction Address fault");
625		}
626		break;
627
628	      case 45:
629		printk(KERN_ERR "Unexpected IA-32 exception (Trap 45)\n");
630		printk(KERN_ERR "  iip - 0x%lx, ifa - 0x%lx, isr - 0x%lx\n",
631		       iip, ifa, isr);
632		force_sig(SIGSEGV, current);
633		return;
634
635	      case 46:
636		printk(KERN_ERR "Unexpected IA-32 intercept trap (Trap 46)\n");
637		printk(KERN_ERR "  iip - 0x%lx, ifa - 0x%lx, isr - 0x%lx, iim - 0x%lx\n",
638		       iip, ifa, isr, iim);
639		force_sig(SIGSEGV, current);
640		return;
641
642	      case 47:
643		sprintf(buf, "IA-32 Interruption Fault (int 0x%lx)", isr >> 16);
644		break;
645
646	      default:
647		sprintf(buf, "Fault %lu", vector);
648		break;
649	}
650	if (!die_if_kernel(buf, &regs, error))
651		force_sig(SIGILL, current);
652}