xref: /linux/arch/m68k/kernel/traps.c (revision a67ff6a54095e27093ea501fb143fefe51a536c2)
1 /*
2  *  linux/arch/m68k/kernel/traps.c
3  *
4  *  Copyright (C) 1993, 1994 by Hamish Macdonald
5  *
6  *  68040 fixes by Michael Rausch
7  *  68040 fixes by Martin Apel
8  *  68040 fixes and writeback by Richard Zidlicky
9  *  68060 fixes by Roman Hodek
10  *  68060 fixes by Jesper Skov
11  *
12  * This file is subject to the terms and conditions of the GNU General Public
13  * License.  See the file COPYING in the main directory of this archive
14  * for more details.
15  */
16 
17 /*
18  * Sets up all exception vectors
19  */
20 
21 #include <linux/sched.h>
22 #include <linux/signal.h>
23 #include <linux/kernel.h>
24 #include <linux/mm.h>
25 #include <linux/module.h>
26 #include <linux/user.h>
27 #include <linux/string.h>
28 #include <linux/linkage.h>
29 #include <linux/init.h>
30 #include <linux/ptrace.h>
31 #include <linux/kallsyms.h>
32 
33 #include <asm/setup.h>
34 #include <asm/fpu.h>
35 #include <asm/system.h>
36 #include <asm/uaccess.h>
37 #include <asm/traps.h>
38 #include <asm/pgalloc.h>
39 #include <asm/machdep.h>
40 #include <asm/siginfo.h>
41 
42 
43 static const char *vec_names[] = {
44 	[VEC_RESETSP]	= "RESET SP",
45 	[VEC_RESETPC]	= "RESET PC",
46 	[VEC_BUSERR]	= "BUS ERROR",
47 	[VEC_ADDRERR]	= "ADDRESS ERROR",
48 	[VEC_ILLEGAL]	= "ILLEGAL INSTRUCTION",
49 	[VEC_ZERODIV]	= "ZERO DIVIDE",
50 	[VEC_CHK]	= "CHK",
51 	[VEC_TRAP]	= "TRAPcc",
52 	[VEC_PRIV]	= "PRIVILEGE VIOLATION",
53 	[VEC_TRACE]	= "TRACE",
54 	[VEC_LINE10]	= "LINE 1010",
55 	[VEC_LINE11]	= "LINE 1111",
56 	[VEC_RESV12]	= "UNASSIGNED RESERVED 12",
57 	[VEC_COPROC]	= "COPROCESSOR PROTOCOL VIOLATION",
58 	[VEC_FORMAT]	= "FORMAT ERROR",
59 	[VEC_UNINT]	= "UNINITIALIZED INTERRUPT",
60 	[VEC_RESV16]	= "UNASSIGNED RESERVED 16",
61 	[VEC_RESV17]	= "UNASSIGNED RESERVED 17",
62 	[VEC_RESV18]	= "UNASSIGNED RESERVED 18",
63 	[VEC_RESV19]	= "UNASSIGNED RESERVED 19",
64 	[VEC_RESV20]	= "UNASSIGNED RESERVED 20",
65 	[VEC_RESV21]	= "UNASSIGNED RESERVED 21",
66 	[VEC_RESV22]	= "UNASSIGNED RESERVED 22",
67 	[VEC_RESV23]	= "UNASSIGNED RESERVED 23",
68 	[VEC_SPUR]	= "SPURIOUS INTERRUPT",
69 	[VEC_INT1]	= "LEVEL 1 INT",
70 	[VEC_INT2]	= "LEVEL 2 INT",
71 	[VEC_INT3]	= "LEVEL 3 INT",
72 	[VEC_INT4]	= "LEVEL 4 INT",
73 	[VEC_INT5]	= "LEVEL 5 INT",
74 	[VEC_INT6]	= "LEVEL 6 INT",
75 	[VEC_INT7]	= "LEVEL 7 INT",
76 	[VEC_SYS]	= "SYSCALL",
77 	[VEC_TRAP1]	= "TRAP #1",
78 	[VEC_TRAP2]	= "TRAP #2",
79 	[VEC_TRAP3]	= "TRAP #3",
80 	[VEC_TRAP4]	= "TRAP #4",
81 	[VEC_TRAP5]	= "TRAP #5",
82 	[VEC_TRAP6]	= "TRAP #6",
83 	[VEC_TRAP7]	= "TRAP #7",
84 	[VEC_TRAP8]	= "TRAP #8",
85 	[VEC_TRAP9]	= "TRAP #9",
86 	[VEC_TRAP10]	= "TRAP #10",
87 	[VEC_TRAP11]	= "TRAP #11",
88 	[VEC_TRAP12]	= "TRAP #12",
89 	[VEC_TRAP13]	= "TRAP #13",
90 	[VEC_TRAP14]	= "TRAP #14",
91 	[VEC_TRAP15]	= "TRAP #15",
92 	[VEC_FPBRUC]	= "FPCP BSUN",
93 	[VEC_FPIR]	= "FPCP INEXACT",
94 	[VEC_FPDIVZ]	= "FPCP DIV BY 0",
95 	[VEC_FPUNDER]	= "FPCP UNDERFLOW",
96 	[VEC_FPOE]	= "FPCP OPERAND ERROR",
97 	[VEC_FPOVER]	= "FPCP OVERFLOW",
98 	[VEC_FPNAN]	= "FPCP SNAN",
99 	[VEC_FPUNSUP]	= "FPCP UNSUPPORTED OPERATION",
100 	[VEC_MMUCFG]	= "MMU CONFIGURATION ERROR",
101 	[VEC_MMUILL]	= "MMU ILLEGAL OPERATION ERROR",
102 	[VEC_MMUACC]	= "MMU ACCESS LEVEL VIOLATION ERROR",
103 	[VEC_RESV59]	= "UNASSIGNED RESERVED 59",
104 	[VEC_UNIMPEA]	= "UNASSIGNED RESERVED 60",
105 	[VEC_UNIMPII]	= "UNASSIGNED RESERVED 61",
106 	[VEC_RESV62]	= "UNASSIGNED RESERVED 62",
107 	[VEC_RESV63]	= "UNASSIGNED RESERVED 63",
108 };
109 
110 static const char *space_names[] = {
111 	[0]		= "Space 0",
112 	[USER_DATA]	= "User Data",
113 	[USER_PROGRAM]	= "User Program",
114 #ifndef CONFIG_SUN3
115 	[3]		= "Space 3",
116 #else
117 	[FC_CONTROL]	= "Control",
118 #endif
119 	[4]		= "Space 4",
120 	[SUPER_DATA]	= "Super Data",
121 	[SUPER_PROGRAM]	= "Super Program",
122 	[CPU_SPACE]	= "CPU"
123 };
124 
125 void die_if_kernel(char *,struct pt_regs *,int);
126 asmlinkage int do_page_fault(struct pt_regs *regs, unsigned long address,
127                              unsigned long error_code);
128 int send_fault_sig(struct pt_regs *regs);
129 
130 asmlinkage void trap_c(struct frame *fp);
131 
132 #if defined (CONFIG_M68060)
133 static inline void access_error060 (struct frame *fp)
134 {
135 	unsigned long fslw = fp->un.fmt4.pc; /* is really FSLW for access error */
136 
137 #ifdef DEBUG
138 	printk("fslw=%#lx, fa=%#lx\n", fslw, fp->un.fmt4.effaddr);
139 #endif
140 
141 	if (fslw & MMU060_BPE) {
142 		/* branch prediction error -> clear branch cache */
143 		__asm__ __volatile__ ("movec %/cacr,%/d0\n\t"
144 				      "orl   #0x00400000,%/d0\n\t"
145 				      "movec %/d0,%/cacr"
146 				      : : : "d0" );
147 		/* return if there's no other error */
148 		if (!(fslw & MMU060_ERR_BITS) && !(fslw & MMU060_SEE))
149 			return;
150 	}
151 
152 	if (fslw & (MMU060_DESC_ERR | MMU060_WP | MMU060_SP)) {
153 		unsigned long errorcode;
154 		unsigned long addr = fp->un.fmt4.effaddr;
155 
156 		if (fslw & MMU060_MA)
157 			addr = (addr + PAGE_SIZE - 1) & PAGE_MASK;
158 
159 		errorcode = 1;
160 		if (fslw & MMU060_DESC_ERR) {
161 			__flush_tlb040_one(addr);
162 			errorcode = 0;
163 		}
164 		if (fslw & MMU060_W)
165 			errorcode |= 2;
166 #ifdef DEBUG
167 		printk("errorcode = %d\n", errorcode );
168 #endif
169 		do_page_fault(&fp->ptregs, addr, errorcode);
170 	} else if (fslw & (MMU060_SEE)){
171 		/* Software Emulation Error.
172 		 * fault during mem_read/mem_write in ifpsp060/os.S
173 		 */
174 		send_fault_sig(&fp->ptregs);
175 	} else if (!(fslw & (MMU060_RE|MMU060_WE)) ||
176 		   send_fault_sig(&fp->ptregs) > 0) {
177 		printk("pc=%#lx, fa=%#lx\n", fp->ptregs.pc, fp->un.fmt4.effaddr);
178 		printk( "68060 access error, fslw=%lx\n", fslw );
179 		trap_c( fp );
180 	}
181 }
182 #endif /* CONFIG_M68060 */
183 
184 #if defined (CONFIG_M68040)
185 static inline unsigned long probe040(int iswrite, unsigned long addr, int wbs)
186 {
187 	unsigned long mmusr;
188 	mm_segment_t old_fs = get_fs();
189 
190 	set_fs(MAKE_MM_SEG(wbs));
191 
192 	if (iswrite)
193 		asm volatile (".chip 68040; ptestw (%0); .chip 68k" : : "a" (addr));
194 	else
195 		asm volatile (".chip 68040; ptestr (%0); .chip 68k" : : "a" (addr));
196 
197 	asm volatile (".chip 68040; movec %%mmusr,%0; .chip 68k" : "=r" (mmusr));
198 
199 	set_fs(old_fs);
200 
201 	return mmusr;
202 }
203 
204 static inline int do_040writeback1(unsigned short wbs, unsigned long wba,
205 				   unsigned long wbd)
206 {
207 	int res = 0;
208 	mm_segment_t old_fs = get_fs();
209 
210 	/* set_fs can not be moved, otherwise put_user() may oops */
211 	set_fs(MAKE_MM_SEG(wbs));
212 
213 	switch (wbs & WBSIZ_040) {
214 	case BA_SIZE_BYTE:
215 		res = put_user(wbd & 0xff, (char __user *)wba);
216 		break;
217 	case BA_SIZE_WORD:
218 		res = put_user(wbd & 0xffff, (short __user *)wba);
219 		break;
220 	case BA_SIZE_LONG:
221 		res = put_user(wbd, (int __user *)wba);
222 		break;
223 	}
224 
225 	/* set_fs can not be moved, otherwise put_user() may oops */
226 	set_fs(old_fs);
227 
228 
229 #ifdef DEBUG
230 	printk("do_040writeback1, res=%d\n",res);
231 #endif
232 
233 	return res;
234 }
235 
236 /* after an exception in a writeback the stack frame corresponding
237  * to that exception is discarded, set a few bits in the old frame
238  * to simulate what it should look like
239  */
240 static inline void fix_xframe040(struct frame *fp, unsigned long wba, unsigned short wbs)
241 {
242 	fp->un.fmt7.faddr = wba;
243 	fp->un.fmt7.ssw = wbs & 0xff;
244 	if (wba != current->thread.faddr)
245 	    fp->un.fmt7.ssw |= MA_040;
246 }
247 
248 static inline void do_040writebacks(struct frame *fp)
249 {
250 	int res = 0;
251 #if 0
252 	if (fp->un.fmt7.wb1s & WBV_040)
253 		printk("access_error040: cannot handle 1st writeback. oops.\n");
254 #endif
255 
256 	if ((fp->un.fmt7.wb2s & WBV_040) &&
257 	    !(fp->un.fmt7.wb2s & WBTT_040)) {
258 		res = do_040writeback1(fp->un.fmt7.wb2s, fp->un.fmt7.wb2a,
259 				       fp->un.fmt7.wb2d);
260 		if (res)
261 			fix_xframe040(fp, fp->un.fmt7.wb2a, fp->un.fmt7.wb2s);
262 		else
263 			fp->un.fmt7.wb2s = 0;
264 	}
265 
266 	/* do the 2nd wb only if the first one was successful (except for a kernel wb) */
267 	if (fp->un.fmt7.wb3s & WBV_040 && (!res || fp->un.fmt7.wb3s & 4)) {
268 		res = do_040writeback1(fp->un.fmt7.wb3s, fp->un.fmt7.wb3a,
269 				       fp->un.fmt7.wb3d);
270 		if (res)
271 		    {
272 			fix_xframe040(fp, fp->un.fmt7.wb3a, fp->un.fmt7.wb3s);
273 
274 			fp->un.fmt7.wb2s = fp->un.fmt7.wb3s;
275 			fp->un.fmt7.wb3s &= (~WBV_040);
276 			fp->un.fmt7.wb2a = fp->un.fmt7.wb3a;
277 			fp->un.fmt7.wb2d = fp->un.fmt7.wb3d;
278 		    }
279 		else
280 			fp->un.fmt7.wb3s = 0;
281 	}
282 
283 	if (res)
284 		send_fault_sig(&fp->ptregs);
285 }
286 
287 /*
288  * called from sigreturn(), must ensure userspace code didn't
289  * manipulate exception frame to circumvent protection, then complete
290  * pending writebacks
291  * we just clear TM2 to turn it into a userspace access
292  */
293 asmlinkage void berr_040cleanup(struct frame *fp)
294 {
295 	fp->un.fmt7.wb2s &= ~4;
296 	fp->un.fmt7.wb3s &= ~4;
297 
298 	do_040writebacks(fp);
299 }
300 
301 static inline void access_error040(struct frame *fp)
302 {
303 	unsigned short ssw = fp->un.fmt7.ssw;
304 	unsigned long mmusr;
305 
306 #ifdef DEBUG
307 	printk("ssw=%#x, fa=%#lx\n", ssw, fp->un.fmt7.faddr);
308         printk("wb1s=%#x, wb2s=%#x, wb3s=%#x\n", fp->un.fmt7.wb1s,
309 		fp->un.fmt7.wb2s, fp->un.fmt7.wb3s);
310 	printk ("wb2a=%lx, wb3a=%lx, wb2d=%lx, wb3d=%lx\n",
311 		fp->un.fmt7.wb2a, fp->un.fmt7.wb3a,
312 		fp->un.fmt7.wb2d, fp->un.fmt7.wb3d);
313 #endif
314 
315 	if (ssw & ATC_040) {
316 		unsigned long addr = fp->un.fmt7.faddr;
317 		unsigned long errorcode;
318 
319 		/*
320 		 * The MMU status has to be determined AFTER the address
321 		 * has been corrected if there was a misaligned access (MA).
322 		 */
323 		if (ssw & MA_040)
324 			addr = (addr + 7) & -8;
325 
326 		/* MMU error, get the MMUSR info for this access */
327 		mmusr = probe040(!(ssw & RW_040), addr, ssw);
328 #ifdef DEBUG
329 		printk("mmusr = %lx\n", mmusr);
330 #endif
331 		errorcode = 1;
332 		if (!(mmusr & MMU_R_040)) {
333 			/* clear the invalid atc entry */
334 			__flush_tlb040_one(addr);
335 			errorcode = 0;
336 		}
337 
338 		/* despite what documentation seems to say, RMW
339 		 * accesses have always both the LK and RW bits set */
340 		if (!(ssw & RW_040) || (ssw & LK_040))
341 			errorcode |= 2;
342 
343 		if (do_page_fault(&fp->ptregs, addr, errorcode)) {
344 #ifdef DEBUG
345 			printk("do_page_fault() !=0\n");
346 #endif
347 			if (user_mode(&fp->ptregs)){
348 				/* delay writebacks after signal delivery */
349 #ifdef DEBUG
350 			        printk(".. was usermode - return\n");
351 #endif
352 				return;
353 			}
354 			/* disable writeback into user space from kernel
355 			 * (if do_page_fault didn't fix the mapping,
356                          * the writeback won't do good)
357 			 */
358 disable_wb:
359 #ifdef DEBUG
360 			printk(".. disabling wb2\n");
361 #endif
362 			if (fp->un.fmt7.wb2a == fp->un.fmt7.faddr)
363 				fp->un.fmt7.wb2s &= ~WBV_040;
364 			if (fp->un.fmt7.wb3a == fp->un.fmt7.faddr)
365 				fp->un.fmt7.wb3s &= ~WBV_040;
366 		}
367 	} else {
368 		/* In case of a bus error we either kill the process or expect
369 		 * the kernel to catch the fault, which then is also responsible
370 		 * for cleaning up the mess.
371 		 */
372 		current->thread.signo = SIGBUS;
373 		current->thread.faddr = fp->un.fmt7.faddr;
374 		if (send_fault_sig(&fp->ptregs) >= 0)
375 			printk("68040 bus error (ssw=%x, faddr=%lx)\n", ssw,
376 			       fp->un.fmt7.faddr);
377 		goto disable_wb;
378 	}
379 
380 	do_040writebacks(fp);
381 }
382 #endif /* CONFIG_M68040 */
383 
384 #if defined(CONFIG_SUN3)
385 #include <asm/sun3mmu.h>
386 
387 extern int mmu_emu_handle_fault (unsigned long, int, int);
388 
389 /* sun3 version of bus_error030 */
390 
391 static inline void bus_error030 (struct frame *fp)
392 {
393 	unsigned char buserr_type = sun3_get_buserr ();
394 	unsigned long addr, errorcode;
395 	unsigned short ssw = fp->un.fmtb.ssw;
396 	extern unsigned long _sun3_map_test_start, _sun3_map_test_end;
397 
398 #ifdef DEBUG
399 	if (ssw & (FC | FB))
400 		printk ("Instruction fault at %#010lx\n",
401 			ssw & FC ?
402 			fp->ptregs.format == 0xa ? fp->ptregs.pc + 2 : fp->un.fmtb.baddr - 2
403 			:
404 			fp->ptregs.format == 0xa ? fp->ptregs.pc + 4 : fp->un.fmtb.baddr);
405 	if (ssw & DF)
406 		printk ("Data %s fault at %#010lx in %s (pc=%#lx)\n",
407 			ssw & RW ? "read" : "write",
408 			fp->un.fmtb.daddr,
409 			space_names[ssw & DFC], fp->ptregs.pc);
410 #endif
411 
412 	/*
413 	 * Check if this page should be demand-mapped. This needs to go before
414 	 * the testing for a bad kernel-space access (demand-mapping applies
415 	 * to kernel accesses too).
416 	 */
417 
418 	if ((ssw & DF)
419 	    && (buserr_type & (SUN3_BUSERR_PROTERR | SUN3_BUSERR_INVALID))) {
420 		if (mmu_emu_handle_fault (fp->un.fmtb.daddr, ssw & RW, 0))
421 			return;
422 	}
423 
424 	/* Check for kernel-space pagefault (BAD). */
425 	if (fp->ptregs.sr & PS_S) {
426 		/* kernel fault must be a data fault to user space */
427 		if (! ((ssw & DF) && ((ssw & DFC) == USER_DATA))) {
428 		     // try checking the kernel mappings before surrender
429 		     if (mmu_emu_handle_fault (fp->un.fmtb.daddr, ssw & RW, 1))
430 			  return;
431 			/* instruction fault or kernel data fault! */
432 			if (ssw & (FC | FB))
433 				printk ("Instruction fault at %#010lx\n",
434 					fp->ptregs.pc);
435 			if (ssw & DF) {
436 				/* was this fault incurred testing bus mappings? */
437 				if((fp->ptregs.pc >= (unsigned long)&_sun3_map_test_start) &&
438 				   (fp->ptregs.pc <= (unsigned long)&_sun3_map_test_end)) {
439 					send_fault_sig(&fp->ptregs);
440 					return;
441 				}
442 
443 				printk ("Data %s fault at %#010lx in %s (pc=%#lx)\n",
444 					ssw & RW ? "read" : "write",
445 					fp->un.fmtb.daddr,
446 					space_names[ssw & DFC], fp->ptregs.pc);
447 			}
448 			printk ("BAD KERNEL BUSERR\n");
449 
450 			die_if_kernel("Oops", &fp->ptregs,0);
451 			force_sig(SIGKILL, current);
452 			return;
453 		}
454 	} else {
455 		/* user fault */
456 		if (!(ssw & (FC | FB)) && !(ssw & DF))
457 			/* not an instruction fault or data fault! BAD */
458 			panic ("USER BUSERR w/o instruction or data fault");
459 	}
460 
461 
462 	/* First handle the data fault, if any.  */
463 	if (ssw & DF) {
464 		addr = fp->un.fmtb.daddr;
465 
466 // errorcode bit 0:	0 -> no page		1 -> protection fault
467 // errorcode bit 1:	0 -> read fault		1 -> write fault
468 
469 // (buserr_type & SUN3_BUSERR_PROTERR)	-> protection fault
470 // (buserr_type & SUN3_BUSERR_INVALID)	-> invalid page fault
471 
472 		if (buserr_type & SUN3_BUSERR_PROTERR)
473 			errorcode = 0x01;
474 		else if (buserr_type & SUN3_BUSERR_INVALID)
475 			errorcode = 0x00;
476 		else {
477 #ifdef DEBUG
478 			printk ("*** unexpected busfault type=%#04x\n", buserr_type);
479 			printk ("invalid %s access at %#lx from pc %#lx\n",
480 				!(ssw & RW) ? "write" : "read", addr,
481 				fp->ptregs.pc);
482 #endif
483 			die_if_kernel ("Oops", &fp->ptregs, buserr_type);
484 			force_sig (SIGBUS, current);
485 			return;
486 		}
487 
488 //todo: wtf is RM bit? --m
489 		if (!(ssw & RW) || ssw & RM)
490 			errorcode |= 0x02;
491 
492 		/* Handle page fault. */
493 		do_page_fault (&fp->ptregs, addr, errorcode);
494 
495 		/* Retry the data fault now. */
496 		return;
497 	}
498 
499 	/* Now handle the instruction fault. */
500 
501 	/* Get the fault address. */
502 	if (fp->ptregs.format == 0xA)
503 		addr = fp->ptregs.pc + 4;
504 	else
505 		addr = fp->un.fmtb.baddr;
506 	if (ssw & FC)
507 		addr -= 2;
508 
509 	if (buserr_type & SUN3_BUSERR_INVALID) {
510 		if (!mmu_emu_handle_fault (fp->un.fmtb.daddr, 1, 0))
511 			do_page_fault (&fp->ptregs, addr, 0);
512        } else {
513 #ifdef DEBUG
514 		printk ("protection fault on insn access (segv).\n");
515 #endif
516 		force_sig (SIGSEGV, current);
517        }
518 }
519 #else
520 #if defined(CPU_M68020_OR_M68030)
521 static inline void bus_error030 (struct frame *fp)
522 {
523 	volatile unsigned short temp;
524 	unsigned short mmusr;
525 	unsigned long addr, errorcode;
526 	unsigned short ssw = fp->un.fmtb.ssw;
527 #ifdef DEBUG
528 	unsigned long desc;
529 
530 	printk ("pid = %x  ", current->pid);
531 	printk ("SSW=%#06x  ", ssw);
532 
533 	if (ssw & (FC | FB))
534 		printk ("Instruction fault at %#010lx\n",
535 			ssw & FC ?
536 			fp->ptregs.format == 0xa ? fp->ptregs.pc + 2 : fp->un.fmtb.baddr - 2
537 			:
538 			fp->ptregs.format == 0xa ? fp->ptregs.pc + 4 : fp->un.fmtb.baddr);
539 	if (ssw & DF)
540 		printk ("Data %s fault at %#010lx in %s (pc=%#lx)\n",
541 			ssw & RW ? "read" : "write",
542 			fp->un.fmtb.daddr,
543 			space_names[ssw & DFC], fp->ptregs.pc);
544 #endif
545 
546 	/* ++andreas: If a data fault and an instruction fault happen
547 	   at the same time map in both pages.  */
548 
549 	/* First handle the data fault, if any.  */
550 	if (ssw & DF) {
551 		addr = fp->un.fmtb.daddr;
552 
553 #ifdef DEBUG
554 		asm volatile ("ptestr %3,%2@,#7,%0\n\t"
555 			      "pmove %%psr,%1@"
556 			      : "=a&" (desc)
557 			      : "a" (&temp), "a" (addr), "d" (ssw));
558 #else
559 		asm volatile ("ptestr %2,%1@,#7\n\t"
560 			      "pmove %%psr,%0@"
561 			      : : "a" (&temp), "a" (addr), "d" (ssw));
562 #endif
563 		mmusr = temp;
564 
565 #ifdef DEBUG
566 		printk("mmusr is %#x for addr %#lx in task %p\n",
567 		       mmusr, addr, current);
568 		printk("descriptor address is %#lx, contents %#lx\n",
569 		       __va(desc), *(unsigned long *)__va(desc));
570 #endif
571 
572 		errorcode = (mmusr & MMU_I) ? 0 : 1;
573 		if (!(ssw & RW) || (ssw & RM))
574 			errorcode |= 2;
575 
576 		if (mmusr & (MMU_I | MMU_WP)) {
577 			if (ssw & 4) {
578 				printk("Data %s fault at %#010lx in %s (pc=%#lx)\n",
579 				       ssw & RW ? "read" : "write",
580 				       fp->un.fmtb.daddr,
581 				       space_names[ssw & DFC], fp->ptregs.pc);
582 				goto buserr;
583 			}
584 			/* Don't try to do anything further if an exception was
585 			   handled. */
586 			if (do_page_fault (&fp->ptregs, addr, errorcode) < 0)
587 				return;
588 		} else if (!(mmusr & MMU_I)) {
589 			/* probably a 020 cas fault */
590 			if (!(ssw & RM) && send_fault_sig(&fp->ptregs) > 0)
591 				printk("unexpected bus error (%#x,%#x)\n", ssw, mmusr);
592 		} else if (mmusr & (MMU_B|MMU_L|MMU_S)) {
593 			printk("invalid %s access at %#lx from pc %#lx\n",
594 			       !(ssw & RW) ? "write" : "read", addr,
595 			       fp->ptregs.pc);
596 			die_if_kernel("Oops",&fp->ptregs,mmusr);
597 			force_sig(SIGSEGV, current);
598 			return;
599 		} else {
600 #if 0
601 			static volatile long tlong;
602 #endif
603 
604 			printk("weird %s access at %#lx from pc %#lx (ssw is %#x)\n",
605 			       !(ssw & RW) ? "write" : "read", addr,
606 			       fp->ptregs.pc, ssw);
607 			asm volatile ("ptestr #1,%1@,#0\n\t"
608 				      "pmove %%psr,%0@"
609 				      : /* no outputs */
610 				      : "a" (&temp), "a" (addr));
611 			mmusr = temp;
612 
613 			printk ("level 0 mmusr is %#x\n", mmusr);
614 #if 0
615 			asm volatile ("pmove %%tt0,%0@"
616 				      : /* no outputs */
617 				      : "a" (&tlong));
618 			printk("tt0 is %#lx, ", tlong);
619 			asm volatile ("pmove %%tt1,%0@"
620 				      : /* no outputs */
621 				      : "a" (&tlong));
622 			printk("tt1 is %#lx\n", tlong);
623 #endif
624 #ifdef DEBUG
625 			printk("Unknown SIGSEGV - 1\n");
626 #endif
627 			die_if_kernel("Oops",&fp->ptregs,mmusr);
628 			force_sig(SIGSEGV, current);
629 			return;
630 		}
631 
632 		/* setup an ATC entry for the access about to be retried */
633 		if (!(ssw & RW) || (ssw & RM))
634 			asm volatile ("ploadw %1,%0@" : /* no outputs */
635 				      : "a" (addr), "d" (ssw));
636 		else
637 			asm volatile ("ploadr %1,%0@" : /* no outputs */
638 				      : "a" (addr), "d" (ssw));
639 	}
640 
641 	/* Now handle the instruction fault. */
642 
643 	if (!(ssw & (FC|FB)))
644 		return;
645 
646 	if (fp->ptregs.sr & PS_S) {
647 		printk("Instruction fault at %#010lx\n",
648 			fp->ptregs.pc);
649 	buserr:
650 		printk ("BAD KERNEL BUSERR\n");
651 		die_if_kernel("Oops",&fp->ptregs,0);
652 		force_sig(SIGKILL, current);
653 		return;
654 	}
655 
656 	/* get the fault address */
657 	if (fp->ptregs.format == 10)
658 		addr = fp->ptregs.pc + 4;
659 	else
660 		addr = fp->un.fmtb.baddr;
661 	if (ssw & FC)
662 		addr -= 2;
663 
664 	if ((ssw & DF) && ((addr ^ fp->un.fmtb.daddr) & PAGE_MASK) == 0)
665 		/* Insn fault on same page as data fault.  But we
666 		   should still create the ATC entry.  */
667 		goto create_atc_entry;
668 
669 #ifdef DEBUG
670 	asm volatile ("ptestr #1,%2@,#7,%0\n\t"
671 		      "pmove %%psr,%1@"
672 		      : "=a&" (desc)
673 		      : "a" (&temp), "a" (addr));
674 #else
675 	asm volatile ("ptestr #1,%1@,#7\n\t"
676 		      "pmove %%psr,%0@"
677 		      : : "a" (&temp), "a" (addr));
678 #endif
679 	mmusr = temp;
680 
681 #ifdef DEBUG
682 	printk ("mmusr is %#x for addr %#lx in task %p\n",
683 		mmusr, addr, current);
684 	printk ("descriptor address is %#lx, contents %#lx\n",
685 		__va(desc), *(unsigned long *)__va(desc));
686 #endif
687 
688 	if (mmusr & MMU_I)
689 		do_page_fault (&fp->ptregs, addr, 0);
690 	else if (mmusr & (MMU_B|MMU_L|MMU_S)) {
691 		printk ("invalid insn access at %#lx from pc %#lx\n",
692 			addr, fp->ptregs.pc);
693 #ifdef DEBUG
694 		printk("Unknown SIGSEGV - 2\n");
695 #endif
696 		die_if_kernel("Oops",&fp->ptregs,mmusr);
697 		force_sig(SIGSEGV, current);
698 		return;
699 	}
700 
701 create_atc_entry:
702 	/* setup an ATC entry for the access about to be retried */
703 	asm volatile ("ploadr #2,%0@" : /* no outputs */
704 		      : "a" (addr));
705 }
706 #endif /* CPU_M68020_OR_M68030 */
707 #endif /* !CONFIG_SUN3 */
708 
709 asmlinkage void buserr_c(struct frame *fp)
710 {
711 	/* Only set esp0 if coming from user mode */
712 	if (user_mode(&fp->ptregs))
713 		current->thread.esp0 = (unsigned long) fp;
714 
715 #ifdef DEBUG
716 	printk ("*** Bus Error *** Format is %x\n", fp->ptregs.format);
717 #endif
718 
719 	switch (fp->ptregs.format) {
720 #if defined (CONFIG_M68060)
721 	case 4:				/* 68060 access error */
722 	  access_error060 (fp);
723 	  break;
724 #endif
725 #if defined (CONFIG_M68040)
726 	case 0x7:			/* 68040 access error */
727 	  access_error040 (fp);
728 	  break;
729 #endif
730 #if defined (CPU_M68020_OR_M68030)
731 	case 0xa:
732 	case 0xb:
733 	  bus_error030 (fp);
734 	  break;
735 #endif
736 	default:
737 	  die_if_kernel("bad frame format",&fp->ptregs,0);
738 #ifdef DEBUG
739 	  printk("Unknown SIGSEGV - 4\n");
740 #endif
741 	  force_sig(SIGSEGV, current);
742 	}
743 }
744 
745 
746 static int kstack_depth_to_print = 48;
747 
748 void show_trace(unsigned long *stack)
749 {
750 	unsigned long *endstack;
751 	unsigned long addr;
752 	int i;
753 
754 	printk("Call Trace:");
755 	addr = (unsigned long)stack + THREAD_SIZE - 1;
756 	endstack = (unsigned long *)(addr & -THREAD_SIZE);
757 	i = 0;
758 	while (stack + 1 <= endstack) {
759 		addr = *stack++;
760 		/*
761 		 * If the address is either in the text segment of the
762 		 * kernel, or in the region which contains vmalloc'ed
763 		 * memory, it *may* be the address of a calling
764 		 * routine; if so, print it so that someone tracing
765 		 * down the cause of the crash will be able to figure
766 		 * out the call path that was taken.
767 		 */
768 		if (__kernel_text_address(addr)) {
769 #ifndef CONFIG_KALLSYMS
770 			if (i % 5 == 0)
771 				printk("\n       ");
772 #endif
773 			printk(" [<%08lx>] %pS\n", addr, (void *)addr);
774 			i++;
775 		}
776 	}
777 	printk("\n");
778 }
779 
780 void show_registers(struct pt_regs *regs)
781 {
782 	struct frame *fp = (struct frame *)regs;
783 	mm_segment_t old_fs = get_fs();
784 	u16 c, *cp;
785 	unsigned long addr;
786 	int i;
787 
788 	print_modules();
789 	printk("PC: [<%08lx>] %pS\n", regs->pc, (void *)regs->pc);
790 	printk("SR: %04x  SP: %p  a2: %08lx\n", regs->sr, regs, regs->a2);
791 	printk("d0: %08lx    d1: %08lx    d2: %08lx    d3: %08lx\n",
792 	       regs->d0, regs->d1, regs->d2, regs->d3);
793 	printk("d4: %08lx    d5: %08lx    a0: %08lx    a1: %08lx\n",
794 	       regs->d4, regs->d5, regs->a0, regs->a1);
795 
796 	printk("Process %s (pid: %d, task=%p)\n",
797 		current->comm, task_pid_nr(current), current);
798 	addr = (unsigned long)&fp->un;
799 	printk("Frame format=%X ", regs->format);
800 	switch (regs->format) {
801 	case 0x2:
802 		printk("instr addr=%08lx\n", fp->un.fmt2.iaddr);
803 		addr += sizeof(fp->un.fmt2);
804 		break;
805 	case 0x3:
806 		printk("eff addr=%08lx\n", fp->un.fmt3.effaddr);
807 		addr += sizeof(fp->un.fmt3);
808 		break;
809 	case 0x4:
810 		printk((CPU_IS_060 ? "fault addr=%08lx fslw=%08lx\n"
811 			: "eff addr=%08lx pc=%08lx\n"),
812 			fp->un.fmt4.effaddr, fp->un.fmt4.pc);
813 		addr += sizeof(fp->un.fmt4);
814 		break;
815 	case 0x7:
816 		printk("eff addr=%08lx ssw=%04x faddr=%08lx\n",
817 			fp->un.fmt7.effaddr, fp->un.fmt7.ssw, fp->un.fmt7.faddr);
818 		printk("wb 1 stat/addr/data: %04x %08lx %08lx\n",
819 			fp->un.fmt7.wb1s, fp->un.fmt7.wb1a, fp->un.fmt7.wb1dpd0);
820 		printk("wb 2 stat/addr/data: %04x %08lx %08lx\n",
821 			fp->un.fmt7.wb2s, fp->un.fmt7.wb2a, fp->un.fmt7.wb2d);
822 		printk("wb 3 stat/addr/data: %04x %08lx %08lx\n",
823 			fp->un.fmt7.wb3s, fp->un.fmt7.wb3a, fp->un.fmt7.wb3d);
824 		printk("push data: %08lx %08lx %08lx %08lx\n",
825 			fp->un.fmt7.wb1dpd0, fp->un.fmt7.pd1, fp->un.fmt7.pd2,
826 			fp->un.fmt7.pd3);
827 		addr += sizeof(fp->un.fmt7);
828 		break;
829 	case 0x9:
830 		printk("instr addr=%08lx\n", fp->un.fmt9.iaddr);
831 		addr += sizeof(fp->un.fmt9);
832 		break;
833 	case 0xa:
834 		printk("ssw=%04x isc=%04x isb=%04x daddr=%08lx dobuf=%08lx\n",
835 			fp->un.fmta.ssw, fp->un.fmta.isc, fp->un.fmta.isb,
836 			fp->un.fmta.daddr, fp->un.fmta.dobuf);
837 		addr += sizeof(fp->un.fmta);
838 		break;
839 	case 0xb:
840 		printk("ssw=%04x isc=%04x isb=%04x daddr=%08lx dobuf=%08lx\n",
841 			fp->un.fmtb.ssw, fp->un.fmtb.isc, fp->un.fmtb.isb,
842 			fp->un.fmtb.daddr, fp->un.fmtb.dobuf);
843 		printk("baddr=%08lx dibuf=%08lx ver=%x\n",
844 			fp->un.fmtb.baddr, fp->un.fmtb.dibuf, fp->un.fmtb.ver);
845 		addr += sizeof(fp->un.fmtb);
846 		break;
847 	default:
848 		printk("\n");
849 	}
850 	show_stack(NULL, (unsigned long *)addr);
851 
852 	printk("Code:");
853 	set_fs(KERNEL_DS);
854 	cp = (u16 *)regs->pc;
855 	for (i = -8; i < 16; i++) {
856 		if (get_user(c, cp + i) && i >= 0) {
857 			printk(" Bad PC value.");
858 			break;
859 		}
860 		printk(i ? " %04x" : " <%04x>", c);
861 	}
862 	set_fs(old_fs);
863 	printk ("\n");
864 }
865 
866 void show_stack(struct task_struct *task, unsigned long *stack)
867 {
868 	unsigned long *p;
869 	unsigned long *endstack;
870 	int i;
871 
872 	if (!stack) {
873 		if (task)
874 			stack = (unsigned long *)task->thread.esp0;
875 		else
876 			stack = (unsigned long *)&stack;
877 	}
878 	endstack = (unsigned long *)(((unsigned long)stack + THREAD_SIZE - 1) & -THREAD_SIZE);
879 
880 	printk("Stack from %08lx:", (unsigned long)stack);
881 	p = stack;
882 	for (i = 0; i < kstack_depth_to_print; i++) {
883 		if (p + 1 > endstack)
884 			break;
885 		if (i % 8 == 0)
886 			printk("\n       ");
887 		printk(" %08lx", *p++);
888 	}
889 	printk("\n");
890 	show_trace(stack);
891 }
892 
893 /*
894  * The architecture-independent backtrace generator
895  */
896 void dump_stack(void)
897 {
898 	unsigned long stack;
899 
900 	show_trace(&stack);
901 }
902 
903 EXPORT_SYMBOL(dump_stack);
904 
905 /*
906  * The vector number returned in the frame pointer may also contain
907  * the "fs" (Fault Status) bits on ColdFire. These are in the bottom
908  * 2 bits, and upper 2 bits. So we need to mask out the real vector
909  * number before using it in comparisons. You don't need to do this on
910  * real 68k parts, but it won't hurt either.
911  */
912 
913 void bad_super_trap (struct frame *fp)
914 {
915 	int vector = (fp->ptregs.vector >> 2) & 0xff;
916 
917 	console_verbose();
918 	if (vector < ARRAY_SIZE(vec_names))
919 		printk ("*** %s ***   FORMAT=%X\n",
920 			vec_names[vector],
921 			fp->ptregs.format);
922 	else
923 		printk ("*** Exception %d ***   FORMAT=%X\n",
924 			vector, fp->ptregs.format);
925 	if (vector == VEC_ADDRERR && CPU_IS_020_OR_030) {
926 		unsigned short ssw = fp->un.fmtb.ssw;
927 
928 		printk ("SSW=%#06x  ", ssw);
929 
930 		if (ssw & RC)
931 			printk ("Pipe stage C instruction fault at %#010lx\n",
932 				(fp->ptregs.format) == 0xA ?
933 				fp->ptregs.pc + 2 : fp->un.fmtb.baddr - 2);
934 		if (ssw & RB)
935 			printk ("Pipe stage B instruction fault at %#010lx\n",
936 				(fp->ptregs.format) == 0xA ?
937 				fp->ptregs.pc + 4 : fp->un.fmtb.baddr);
938 		if (ssw & DF)
939 			printk ("Data %s fault at %#010lx in %s (pc=%#lx)\n",
940 				ssw & RW ? "read" : "write",
941 				fp->un.fmtb.daddr, space_names[ssw & DFC],
942 				fp->ptregs.pc);
943 	}
944 	printk ("Current process id is %d\n", task_pid_nr(current));
945 	die_if_kernel("BAD KERNEL TRAP", &fp->ptregs, 0);
946 }
947 
948 asmlinkage void trap_c(struct frame *fp)
949 {
950 	int sig;
951 	int vector = (fp->ptregs.vector >> 2) & 0xff;
952 	siginfo_t info;
953 
954 	if (fp->ptregs.sr & PS_S) {
955 		if (vector == VEC_TRACE) {
956 			/* traced a trapping instruction on a 68020/30,
957 			 * real exception will be executed afterwards.
958 			 */
959 		} else if (!handle_kernel_fault(&fp->ptregs))
960 			bad_super_trap(fp);
961 		return;
962 	}
963 
964 	/* send the appropriate signal to the user program */
965 	switch (vector) {
966 	    case VEC_ADDRERR:
967 		info.si_code = BUS_ADRALN;
968 		sig = SIGBUS;
969 		break;
970 	    case VEC_ILLEGAL:
971 	    case VEC_LINE10:
972 	    case VEC_LINE11:
973 		info.si_code = ILL_ILLOPC;
974 		sig = SIGILL;
975 		break;
976 	    case VEC_PRIV:
977 		info.si_code = ILL_PRVOPC;
978 		sig = SIGILL;
979 		break;
980 	    case VEC_COPROC:
981 		info.si_code = ILL_COPROC;
982 		sig = SIGILL;
983 		break;
984 	    case VEC_TRAP1:
985 	    case VEC_TRAP2:
986 	    case VEC_TRAP3:
987 	    case VEC_TRAP4:
988 	    case VEC_TRAP5:
989 	    case VEC_TRAP6:
990 	    case VEC_TRAP7:
991 	    case VEC_TRAP8:
992 	    case VEC_TRAP9:
993 	    case VEC_TRAP10:
994 	    case VEC_TRAP11:
995 	    case VEC_TRAP12:
996 	    case VEC_TRAP13:
997 	    case VEC_TRAP14:
998 		info.si_code = ILL_ILLTRP;
999 		sig = SIGILL;
1000 		break;
1001 	    case VEC_FPBRUC:
1002 	    case VEC_FPOE:
1003 	    case VEC_FPNAN:
1004 		info.si_code = FPE_FLTINV;
1005 		sig = SIGFPE;
1006 		break;
1007 	    case VEC_FPIR:
1008 		info.si_code = FPE_FLTRES;
1009 		sig = SIGFPE;
1010 		break;
1011 	    case VEC_FPDIVZ:
1012 		info.si_code = FPE_FLTDIV;
1013 		sig = SIGFPE;
1014 		break;
1015 	    case VEC_FPUNDER:
1016 		info.si_code = FPE_FLTUND;
1017 		sig = SIGFPE;
1018 		break;
1019 	    case VEC_FPOVER:
1020 		info.si_code = FPE_FLTOVF;
1021 		sig = SIGFPE;
1022 		break;
1023 	    case VEC_ZERODIV:
1024 		info.si_code = FPE_INTDIV;
1025 		sig = SIGFPE;
1026 		break;
1027 	    case VEC_CHK:
1028 	    case VEC_TRAP:
1029 		info.si_code = FPE_INTOVF;
1030 		sig = SIGFPE;
1031 		break;
1032 	    case VEC_TRACE:		/* ptrace single step */
1033 		info.si_code = TRAP_TRACE;
1034 		sig = SIGTRAP;
1035 		break;
1036 	    case VEC_TRAP15:		/* breakpoint */
1037 		info.si_code = TRAP_BRKPT;
1038 		sig = SIGTRAP;
1039 		break;
1040 	    default:
1041 		info.si_code = ILL_ILLOPC;
1042 		sig = SIGILL;
1043 		break;
1044 	}
1045 	info.si_signo = sig;
1046 	info.si_errno = 0;
1047 	switch (fp->ptregs.format) {
1048 	    default:
1049 		info.si_addr = (void *) fp->ptregs.pc;
1050 		break;
1051 	    case 2:
1052 		info.si_addr = (void *) fp->un.fmt2.iaddr;
1053 		break;
1054 	    case 7:
1055 		info.si_addr = (void *) fp->un.fmt7.effaddr;
1056 		break;
1057 	    case 9:
1058 		info.si_addr = (void *) fp->un.fmt9.iaddr;
1059 		break;
1060 	    case 10:
1061 		info.si_addr = (void *) fp->un.fmta.daddr;
1062 		break;
1063 	    case 11:
1064 		info.si_addr = (void *) fp->un.fmtb.daddr;
1065 		break;
1066 	}
1067 	force_sig_info (sig, &info, current);
1068 }
1069 
1070 void die_if_kernel (char *str, struct pt_regs *fp, int nr)
1071 {
1072 	if (!(fp->sr & PS_S))
1073 		return;
1074 
1075 	console_verbose();
1076 	printk("%s: %08x\n",str,nr);
1077 	show_registers(fp);
1078 	add_taint(TAINT_DIE);
1079 	do_exit(SIGSEGV);
1080 }
1081 
1082 asmlinkage void set_esp0(unsigned long ssp)
1083 {
1084 	current->thread.esp0 = ssp;
1085 }
1086 
1087 /*
1088  * This function is called if an error occur while accessing
1089  * user-space from the fpsp040 code.
1090  */
1091 asmlinkage void fpsp040_die(void)
1092 {
1093 	do_exit(SIGSEGV);
1094 }
1095 
1096 #ifdef CONFIG_M68KFPU_EMU
1097 asmlinkage void fpemu_signal(int signal, int code, void *addr)
1098 {
1099 	siginfo_t info;
1100 
1101 	info.si_signo = signal;
1102 	info.si_errno = 0;
1103 	info.si_code = code;
1104 	info.si_addr = addr;
1105 	force_sig_info(signal, &info, current);
1106 }
1107 #endif
1108