xref: /linux/arch/m68k/kernel/traps.c (revision cf21f328fcafacf4f96e7a30ef9dceede1076378)
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/sched/debug.h>
23 #include <linux/signal.h>
24 #include <linux/kernel.h>
25 #include <linux/mm.h>
26 #include <linux/module.h>
27 #include <linux/user.h>
28 #include <linux/string.h>
29 #include <linux/linkage.h>
30 #include <linux/init.h>
31 #include <linux/ptrace.h>
32 #include <linux/kallsyms.h>
33 #include <linux/extable.h>
34 
35 #include <asm/setup.h>
36 #include <asm/fpu.h>
37 #include <linux/uaccess.h>
38 #include <asm/traps.h>
39 #include <asm/machdep.h>
40 #include <asm/processor.h>
41 #include <asm/siginfo.h>
42 #include <asm/tlbflush.h>
43 
44 static const char *vec_names[] = {
45 	[VEC_RESETSP]	= "RESET SP",
46 	[VEC_RESETPC]	= "RESET PC",
47 	[VEC_BUSERR]	= "BUS ERROR",
48 	[VEC_ADDRERR]	= "ADDRESS ERROR",
49 	[VEC_ILLEGAL]	= "ILLEGAL INSTRUCTION",
50 	[VEC_ZERODIV]	= "ZERO DIVIDE",
51 	[VEC_CHK]	= "CHK",
52 	[VEC_TRAP]	= "TRAPcc",
53 	[VEC_PRIV]	= "PRIVILEGE VIOLATION",
54 	[VEC_TRACE]	= "TRACE",
55 	[VEC_LINE10]	= "LINE 1010",
56 	[VEC_LINE11]	= "LINE 1111",
57 	[VEC_RESV12]	= "UNASSIGNED RESERVED 12",
58 	[VEC_COPROC]	= "COPROCESSOR PROTOCOL VIOLATION",
59 	[VEC_FORMAT]	= "FORMAT ERROR",
60 	[VEC_UNINT]	= "UNINITIALIZED INTERRUPT",
61 	[VEC_RESV16]	= "UNASSIGNED RESERVED 16",
62 	[VEC_RESV17]	= "UNASSIGNED RESERVED 17",
63 	[VEC_RESV18]	= "UNASSIGNED RESERVED 18",
64 	[VEC_RESV19]	= "UNASSIGNED RESERVED 19",
65 	[VEC_RESV20]	= "UNASSIGNED RESERVED 20",
66 	[VEC_RESV21]	= "UNASSIGNED RESERVED 21",
67 	[VEC_RESV22]	= "UNASSIGNED RESERVED 22",
68 	[VEC_RESV23]	= "UNASSIGNED RESERVED 23",
69 	[VEC_SPUR]	= "SPURIOUS INTERRUPT",
70 	[VEC_INT1]	= "LEVEL 1 INT",
71 	[VEC_INT2]	= "LEVEL 2 INT",
72 	[VEC_INT3]	= "LEVEL 3 INT",
73 	[VEC_INT4]	= "LEVEL 4 INT",
74 	[VEC_INT5]	= "LEVEL 5 INT",
75 	[VEC_INT6]	= "LEVEL 6 INT",
76 	[VEC_INT7]	= "LEVEL 7 INT",
77 	[VEC_SYS]	= "SYSCALL",
78 	[VEC_TRAP1]	= "TRAP #1",
79 	[VEC_TRAP2]	= "TRAP #2",
80 	[VEC_TRAP3]	= "TRAP #3",
81 	[VEC_TRAP4]	= "TRAP #4",
82 	[VEC_TRAP5]	= "TRAP #5",
83 	[VEC_TRAP6]	= "TRAP #6",
84 	[VEC_TRAP7]	= "TRAP #7",
85 	[VEC_TRAP8]	= "TRAP #8",
86 	[VEC_TRAP9]	= "TRAP #9",
87 	[VEC_TRAP10]	= "TRAP #10",
88 	[VEC_TRAP11]	= "TRAP #11",
89 	[VEC_TRAP12]	= "TRAP #12",
90 	[VEC_TRAP13]	= "TRAP #13",
91 	[VEC_TRAP14]	= "TRAP #14",
92 	[VEC_TRAP15]	= "TRAP #15",
93 	[VEC_FPBRUC]	= "FPCP BSUN",
94 	[VEC_FPIR]	= "FPCP INEXACT",
95 	[VEC_FPDIVZ]	= "FPCP DIV BY 0",
96 	[VEC_FPUNDER]	= "FPCP UNDERFLOW",
97 	[VEC_FPOE]	= "FPCP OPERAND ERROR",
98 	[VEC_FPOVER]	= "FPCP OVERFLOW",
99 	[VEC_FPNAN]	= "FPCP SNAN",
100 	[VEC_FPUNSUP]	= "FPCP UNSUPPORTED OPERATION",
101 	[VEC_MMUCFG]	= "MMU CONFIGURATION ERROR",
102 	[VEC_MMUILL]	= "MMU ILLEGAL OPERATION ERROR",
103 	[VEC_MMUACC]	= "MMU ACCESS LEVEL VIOLATION ERROR",
104 	[VEC_RESV59]	= "UNASSIGNED RESERVED 59",
105 	[VEC_UNIMPEA]	= "UNASSIGNED RESERVED 60",
106 	[VEC_UNIMPII]	= "UNASSIGNED RESERVED 61",
107 	[VEC_RESV62]	= "UNASSIGNED RESERVED 62",
108 	[VEC_RESV63]	= "UNASSIGNED RESERVED 63",
109 };
110 
111 static const char *space_names[] = {
112 	[0]		= "Space 0",
113 	[USER_DATA]	= "User Data",
114 	[USER_PROGRAM]	= "User Program",
115 #ifndef CONFIG_SUN3
116 	[3]		= "Space 3",
117 #else
118 	[FC_CONTROL]	= "Control",
119 #endif
120 	[4]		= "Space 4",
121 	[SUPER_DATA]	= "Super Data",
122 	[SUPER_PROGRAM]	= "Super Program",
123 	[CPU_SPACE]	= "CPU"
124 };
125 
126 void die_if_kernel(char *,struct pt_regs *,int);
127 asmlinkage int do_page_fault(struct pt_regs *regs, unsigned long address,
128                              unsigned long error_code);
129 int send_fault_sig(struct pt_regs *regs);
130 
131 asmlinkage void trap_c(struct frame *fp);
132 
133 #if defined (CONFIG_M68060)
134 static inline void access_error060 (struct frame *fp)
135 {
136 	unsigned long fslw = fp->un.fmt4.pc; /* is really FSLW for access error */
137 
138 	pr_debug("fslw=%#lx, fa=%#lx\n", fslw, fp->un.fmt4.effaddr);
139 
140 	if (fslw & MMU060_BPE) {
141 		/* branch prediction error -> clear branch cache */
142 		__asm__ __volatile__ ("movec %/cacr,%/d0\n\t"
143 				      "orl   #0x00400000,%/d0\n\t"
144 				      "movec %/d0,%/cacr"
145 				      : : : "d0" );
146 		/* return if there's no other error */
147 		if (!(fslw & MMU060_ERR_BITS) && !(fslw & MMU060_SEE))
148 			return;
149 	}
150 
151 	if (fslw & (MMU060_DESC_ERR | MMU060_WP | MMU060_SP)) {
152 		unsigned long errorcode;
153 		unsigned long addr = fp->un.fmt4.effaddr;
154 
155 		if (fslw & MMU060_MA)
156 			addr = (addr + PAGE_SIZE - 1) & PAGE_MASK;
157 
158 		errorcode = 1;
159 		if (fslw & MMU060_DESC_ERR) {
160 			__flush_tlb040_one(addr);
161 			errorcode = 0;
162 		}
163 		if (fslw & MMU060_W)
164 			errorcode |= 2;
165 		pr_debug("errorcode = %ld\n", errorcode);
166 		do_page_fault(&fp->ptregs, addr, errorcode);
167 	} else if (fslw & (MMU060_SEE)){
168 		/* Software Emulation Error.
169 		 * fault during mem_read/mem_write in ifpsp060/os.S
170 		 */
171 		send_fault_sig(&fp->ptregs);
172 	} else if (!(fslw & (MMU060_RE|MMU060_WE)) ||
173 		   send_fault_sig(&fp->ptregs) > 0) {
174 		pr_err("pc=%#lx, fa=%#lx\n", fp->ptregs.pc,
175 		       fp->un.fmt4.effaddr);
176 		pr_err("68060 access error, fslw=%lx\n", fslw);
177 		trap_c( fp );
178 	}
179 }
180 #endif /* CONFIG_M68060 */
181 
182 #if defined (CONFIG_M68040)
183 static inline unsigned long probe040(int iswrite, unsigned long addr, int wbs)
184 {
185 	unsigned long mmusr;
186 
187 	set_fc(wbs);
188 
189 	if (iswrite)
190 		asm volatile (".chip 68040; ptestw (%0); .chip 68k" : : "a" (addr));
191 	else
192 		asm volatile (".chip 68040; ptestr (%0); .chip 68k" : : "a" (addr));
193 
194 	asm volatile (".chip 68040; movec %%mmusr,%0; .chip 68k" : "=r" (mmusr));
195 
196 	set_fc(USER_DATA);
197 
198 	return mmusr;
199 }
200 
201 static inline int do_040writeback1(unsigned short wbs, unsigned long wba,
202 				   unsigned long wbd)
203 {
204 	int res = 0;
205 
206 	set_fc(wbs);
207 
208 	switch (wbs & WBSIZ_040) {
209 	case BA_SIZE_BYTE:
210 		res = put_user(wbd & 0xff, (char __user *)wba);
211 		break;
212 	case BA_SIZE_WORD:
213 		res = put_user(wbd & 0xffff, (short __user *)wba);
214 		break;
215 	case BA_SIZE_LONG:
216 		res = put_user(wbd, (int __user *)wba);
217 		break;
218 	}
219 
220 	set_fc(USER_DATA);
221 
222 	pr_debug("do_040writeback1, res=%d\n", res);
223 
224 	return res;
225 }
226 
227 /* after an exception in a writeback the stack frame corresponding
228  * to that exception is discarded, set a few bits in the old frame
229  * to simulate what it should look like
230  */
231 static inline void fix_xframe040(struct frame *fp, unsigned long wba, unsigned short wbs)
232 {
233 	fp->un.fmt7.faddr = wba;
234 	fp->un.fmt7.ssw = wbs & 0xff;
235 	if (wba != current->thread.faddr)
236 	    fp->un.fmt7.ssw |= MA_040;
237 }
238 
239 static inline void do_040writebacks(struct frame *fp)
240 {
241 	int res = 0;
242 #if 0
243 	if (fp->un.fmt7.wb1s & WBV_040)
244 		pr_err("access_error040: cannot handle 1st writeback. oops.\n");
245 #endif
246 
247 	if ((fp->un.fmt7.wb2s & WBV_040) &&
248 	    !(fp->un.fmt7.wb2s & WBTT_040)) {
249 		res = do_040writeback1(fp->un.fmt7.wb2s, fp->un.fmt7.wb2a,
250 				       fp->un.fmt7.wb2d);
251 		if (res)
252 			fix_xframe040(fp, fp->un.fmt7.wb2a, fp->un.fmt7.wb2s);
253 		else
254 			fp->un.fmt7.wb2s = 0;
255 	}
256 
257 	/* do the 2nd wb only if the first one was successful (except for a kernel wb) */
258 	if (fp->un.fmt7.wb3s & WBV_040 && (!res || fp->un.fmt7.wb3s & 4)) {
259 		res = do_040writeback1(fp->un.fmt7.wb3s, fp->un.fmt7.wb3a,
260 				       fp->un.fmt7.wb3d);
261 		if (res)
262 		    {
263 			fix_xframe040(fp, fp->un.fmt7.wb3a, fp->un.fmt7.wb3s);
264 
265 			fp->un.fmt7.wb2s = fp->un.fmt7.wb3s;
266 			fp->un.fmt7.wb3s &= (~WBV_040);
267 			fp->un.fmt7.wb2a = fp->un.fmt7.wb3a;
268 			fp->un.fmt7.wb2d = fp->un.fmt7.wb3d;
269 		    }
270 		else
271 			fp->un.fmt7.wb3s = 0;
272 	}
273 
274 	if (res)
275 		send_fault_sig(&fp->ptregs);
276 }
277 
278 /*
279  * called from sigreturn(), must ensure userspace code didn't
280  * manipulate exception frame to circumvent protection, then complete
281  * pending writebacks
282  * we just clear TM2 to turn it into a userspace access
283  */
284 asmlinkage void berr_040cleanup(struct frame *fp)
285 {
286 	fp->un.fmt7.wb2s &= ~4;
287 	fp->un.fmt7.wb3s &= ~4;
288 
289 	do_040writebacks(fp);
290 }
291 
292 static inline void access_error040(struct frame *fp)
293 {
294 	unsigned short ssw = fp->un.fmt7.ssw;
295 	unsigned long mmusr;
296 
297 	pr_debug("ssw=%#x, fa=%#lx\n", ssw, fp->un.fmt7.faddr);
298 	pr_debug("wb1s=%#x, wb2s=%#x, wb3s=%#x\n", fp->un.fmt7.wb1s,
299 		fp->un.fmt7.wb2s, fp->un.fmt7.wb3s);
300 	pr_debug("wb2a=%lx, wb3a=%lx, wb2d=%lx, wb3d=%lx\n",
301 		fp->un.fmt7.wb2a, fp->un.fmt7.wb3a,
302 		fp->un.fmt7.wb2d, fp->un.fmt7.wb3d);
303 
304 	if (ssw & ATC_040) {
305 		unsigned long addr = fp->un.fmt7.faddr;
306 		unsigned long errorcode;
307 
308 		/*
309 		 * The MMU status has to be determined AFTER the address
310 		 * has been corrected if there was a misaligned access (MA).
311 		 */
312 		if (ssw & MA_040)
313 			addr = (addr + 7) & -8;
314 
315 		/* MMU error, get the MMUSR info for this access */
316 		mmusr = probe040(!(ssw & RW_040), addr, ssw);
317 		pr_debug("mmusr = %lx\n", mmusr);
318 		errorcode = 1;
319 		if (!(mmusr & MMU_R_040)) {
320 			/* clear the invalid atc entry */
321 			__flush_tlb040_one(addr);
322 			errorcode = 0;
323 		}
324 
325 		/* despite what documentation seems to say, RMW
326 		 * accesses have always both the LK and RW bits set */
327 		if (!(ssw & RW_040) || (ssw & LK_040))
328 			errorcode |= 2;
329 
330 		if (do_page_fault(&fp->ptregs, addr, errorcode)) {
331 			pr_debug("do_page_fault() !=0\n");
332 			if (user_mode(&fp->ptregs)){
333 				/* delay writebacks after signal delivery */
334 				pr_debug(".. was usermode - return\n");
335 				return;
336 			}
337 			/* disable writeback into user space from kernel
338 			 * (if do_page_fault didn't fix the mapping,
339                          * the writeback won't do good)
340 			 */
341 disable_wb:
342 			pr_debug(".. disabling wb2\n");
343 			if (fp->un.fmt7.wb2a == fp->un.fmt7.faddr)
344 				fp->un.fmt7.wb2s &= ~WBV_040;
345 			if (fp->un.fmt7.wb3a == fp->un.fmt7.faddr)
346 				fp->un.fmt7.wb3s &= ~WBV_040;
347 		}
348 	} else {
349 		/* In case of a bus error we either kill the process or expect
350 		 * the kernel to catch the fault, which then is also responsible
351 		 * for cleaning up the mess.
352 		 */
353 		current->thread.signo = SIGBUS;
354 		current->thread.faddr = fp->un.fmt7.faddr;
355 		if (send_fault_sig(&fp->ptregs) >= 0)
356 			pr_err("68040 bus error (ssw=%x, faddr=%lx)\n", ssw,
357 			       fp->un.fmt7.faddr);
358 		goto disable_wb;
359 	}
360 
361 	do_040writebacks(fp);
362 }
363 #endif /* CONFIG_M68040 */
364 
365 #if defined(CONFIG_SUN3)
366 #include <asm/sun3mmu.h>
367 
368 extern int mmu_emu_handle_fault (unsigned long, int, int);
369 
370 /* sun3 version of bus_error030 */
371 
372 static inline void bus_error030 (struct frame *fp)
373 {
374 	unsigned char buserr_type = sun3_get_buserr ();
375 	unsigned long addr, errorcode;
376 	unsigned short ssw = fp->un.fmtb.ssw;
377 	extern unsigned long _sun3_map_test_start, _sun3_map_test_end;
378 
379 	if (ssw & (FC | FB))
380 		pr_debug("Instruction fault at %#010lx\n",
381 			ssw & FC ?
382 			fp->ptregs.format == 0xa ? fp->ptregs.pc + 2 : fp->un.fmtb.baddr - 2
383 			:
384 			fp->ptregs.format == 0xa ? fp->ptregs.pc + 4 : fp->un.fmtb.baddr);
385 	if (ssw & DF)
386 		pr_debug("Data %s fault at %#010lx in %s (pc=%#lx)\n",
387 			ssw & RW ? "read" : "write",
388 			fp->un.fmtb.daddr,
389 			space_names[ssw & DFC], fp->ptregs.pc);
390 
391 	/*
392 	 * Check if this page should be demand-mapped. This needs to go before
393 	 * the testing for a bad kernel-space access (demand-mapping applies
394 	 * to kernel accesses too).
395 	 */
396 
397 	if ((ssw & DF)
398 	    && (buserr_type & (SUN3_BUSERR_PROTERR | SUN3_BUSERR_INVALID))) {
399 		if (mmu_emu_handle_fault (fp->un.fmtb.daddr, ssw & RW, 0))
400 			return;
401 	}
402 
403 	/* Check for kernel-space pagefault (BAD). */
404 	if (fp->ptregs.sr & PS_S) {
405 		/* kernel fault must be a data fault to user space */
406 		if (! ((ssw & DF) && ((ssw & DFC) == USER_DATA))) {
407 		     // try checking the kernel mappings before surrender
408 		     if (mmu_emu_handle_fault (fp->un.fmtb.daddr, ssw & RW, 1))
409 			  return;
410 			/* instruction fault or kernel data fault! */
411 			if (ssw & (FC | FB))
412 				pr_err("Instruction fault at %#010lx\n",
413 					fp->ptregs.pc);
414 			if (ssw & DF) {
415 				/* was this fault incurred testing bus mappings? */
416 				if((fp->ptregs.pc >= (unsigned long)&_sun3_map_test_start) &&
417 				   (fp->ptregs.pc <= (unsigned long)&_sun3_map_test_end)) {
418 					send_fault_sig(&fp->ptregs);
419 					return;
420 				}
421 
422 				pr_err("Data %s fault at %#010lx in %s (pc=%#lx)\n",
423 					ssw & RW ? "read" : "write",
424 					fp->un.fmtb.daddr,
425 					space_names[ssw & DFC], fp->ptregs.pc);
426 			}
427 			pr_err("BAD KERNEL BUSERR\n");
428 
429 			die_if_kernel("Oops", &fp->ptregs,0);
430 			force_sig(SIGKILL);
431 			return;
432 		}
433 	} else {
434 		/* user fault */
435 		if (!(ssw & (FC | FB)) && !(ssw & DF))
436 			/* not an instruction fault or data fault! BAD */
437 			panic ("USER BUSERR w/o instruction or data fault");
438 	}
439 
440 
441 	/* First handle the data fault, if any.  */
442 	if (ssw & DF) {
443 		addr = fp->un.fmtb.daddr;
444 
445 // errorcode bit 0:	0 -> no page		1 -> protection fault
446 // errorcode bit 1:	0 -> read fault		1 -> write fault
447 
448 // (buserr_type & SUN3_BUSERR_PROTERR)	-> protection fault
449 // (buserr_type & SUN3_BUSERR_INVALID)	-> invalid page fault
450 
451 		if (buserr_type & SUN3_BUSERR_PROTERR)
452 			errorcode = 0x01;
453 		else if (buserr_type & SUN3_BUSERR_INVALID)
454 			errorcode = 0x00;
455 		else {
456 			pr_debug("*** unexpected busfault type=%#04x\n",
457 				 buserr_type);
458 			pr_debug("invalid %s access at %#lx from pc %#lx\n",
459 				 !(ssw & RW) ? "write" : "read", addr,
460 				 fp->ptregs.pc);
461 			die_if_kernel ("Oops", &fp->ptregs, buserr_type);
462 			force_sig (SIGBUS);
463 			return;
464 		}
465 
466 //todo: wtf is RM bit? --m
467 		if (!(ssw & RW) || ssw & RM)
468 			errorcode |= 0x02;
469 
470 		/* Handle page fault. */
471 		do_page_fault (&fp->ptregs, addr, errorcode);
472 
473 		/* Retry the data fault now. */
474 		return;
475 	}
476 
477 	/* Now handle the instruction fault. */
478 
479 	/* Get the fault address. */
480 	if (fp->ptregs.format == 0xA)
481 		addr = fp->ptregs.pc + 4;
482 	else
483 		addr = fp->un.fmtb.baddr;
484 	if (ssw & FC)
485 		addr -= 2;
486 
487 	if (buserr_type & SUN3_BUSERR_INVALID) {
488 		if (!mmu_emu_handle_fault(addr, 1, 0))
489 			do_page_fault (&fp->ptregs, addr, 0);
490        } else {
491 		pr_debug("protection fault on insn access (segv).\n");
492 		force_sig (SIGSEGV);
493        }
494 }
495 #else
496 #if defined(CPU_M68020_OR_M68030)
497 static inline void bus_error030 (struct frame *fp)
498 {
499 	volatile unsigned short temp;
500 	unsigned short mmusr;
501 	unsigned long addr, errorcode;
502 	unsigned short ssw = fp->un.fmtb.ssw;
503 #ifdef DEBUG
504 	unsigned long desc;
505 #endif
506 
507 	pr_debug("pid = %x  ", current->pid);
508 	pr_debug("SSW=%#06x  ", ssw);
509 
510 	if (ssw & (FC | FB))
511 		pr_debug("Instruction fault at %#010lx\n",
512 			ssw & FC ?
513 			fp->ptregs.format == 0xa ? fp->ptregs.pc + 2 : fp->un.fmtb.baddr - 2
514 			:
515 			fp->ptregs.format == 0xa ? fp->ptregs.pc + 4 : fp->un.fmtb.baddr);
516 	if (ssw & DF)
517 		pr_debug("Data %s fault at %#010lx in %s (pc=%#lx)\n",
518 			ssw & RW ? "read" : "write",
519 			fp->un.fmtb.daddr,
520 			space_names[ssw & DFC], fp->ptregs.pc);
521 
522 	/* ++andreas: If a data fault and an instruction fault happen
523 	   at the same time map in both pages.  */
524 
525 	/* First handle the data fault, if any.  */
526 	if (ssw & DF) {
527 		addr = fp->un.fmtb.daddr;
528 
529 #ifdef DEBUG
530 		asm volatile ("ptestr %3,%2@,#7,%0\n\t"
531 			      "pmove %%psr,%1"
532 			      : "=a&" (desc), "=m" (temp)
533 			      : "a" (addr), "d" (ssw));
534 		pr_debug("mmusr is %#x for addr %#lx in task %p\n",
535 			 temp, addr, current);
536 		pr_debug("descriptor address is 0x%p, contents %#lx\n",
537 			 __va(desc), *(unsigned long *)__va(desc));
538 #else
539 		asm volatile ("ptestr %2,%1@,#7\n\t"
540 			      "pmove %%psr,%0"
541 			      : "=m" (temp) : "a" (addr), "d" (ssw));
542 #endif
543 		mmusr = temp;
544 		errorcode = (mmusr & MMU_I) ? 0 : 1;
545 		if (!(ssw & RW) || (ssw & RM))
546 			errorcode |= 2;
547 
548 		if (mmusr & (MMU_I | MMU_WP)) {
549 			/* We might have an exception table for this PC */
550 			if (ssw & 4 && !search_exception_tables(fp->ptregs.pc)) {
551 				pr_err("Data %s fault at %#010lx in %s (pc=%#lx)\n",
552 				       ssw & RW ? "read" : "write",
553 				       fp->un.fmtb.daddr,
554 				       space_names[ssw & DFC], fp->ptregs.pc);
555 				goto buserr;
556 			}
557 			/* Don't try to do anything further if an exception was
558 			   handled. */
559 			if (do_page_fault (&fp->ptregs, addr, errorcode) < 0)
560 				return;
561 		} else if (!(mmusr & MMU_I)) {
562 			/* probably a 020 cas fault */
563 			if (!(ssw & RM) && send_fault_sig(&fp->ptregs) > 0)
564 				pr_err("unexpected bus error (%#x,%#x)\n", ssw,
565 				       mmusr);
566 		} else if (mmusr & (MMU_B|MMU_L|MMU_S)) {
567 			pr_err("invalid %s access at %#lx from pc %#lx\n",
568 			       !(ssw & RW) ? "write" : "read", addr,
569 			       fp->ptregs.pc);
570 			die_if_kernel("Oops",&fp->ptregs,mmusr);
571 			force_sig(SIGSEGV);
572 			return;
573 		} else {
574 #if 0
575 			static volatile long tlong;
576 #endif
577 
578 			pr_err("weird %s access at %#lx from pc %#lx (ssw is %#x)\n",
579 			       !(ssw & RW) ? "write" : "read", addr,
580 			       fp->ptregs.pc, ssw);
581 			asm volatile ("ptestr #1,%1@,#0\n\t"
582 				      "pmove %%psr,%0"
583 				      : "=m" (temp)
584 				      : "a" (addr));
585 			mmusr = temp;
586 
587 			pr_err("level 0 mmusr is %#x\n", mmusr);
588 #if 0
589 			asm volatile ("pmove %%tt0,%0"
590 				      : "=m" (tlong));
591 			pr_debug("tt0 is %#lx, ", tlong);
592 			asm volatile ("pmove %%tt1,%0"
593 				      : "=m" (tlong));
594 			pr_debug("tt1 is %#lx\n", tlong);
595 #endif
596 			pr_debug("Unknown SIGSEGV - 1\n");
597 			die_if_kernel("Oops",&fp->ptregs,mmusr);
598 			force_sig(SIGSEGV);
599 			return;
600 		}
601 
602 		/* setup an ATC entry for the access about to be retried */
603 		if (!(ssw & RW) || (ssw & RM))
604 			asm volatile ("ploadw %1,%0@" : /* no outputs */
605 				      : "a" (addr), "d" (ssw));
606 		else
607 			asm volatile ("ploadr %1,%0@" : /* no outputs */
608 				      : "a" (addr), "d" (ssw));
609 	}
610 
611 	/* Now handle the instruction fault. */
612 
613 	if (!(ssw & (FC|FB)))
614 		return;
615 
616 	if (fp->ptregs.sr & PS_S) {
617 		pr_err("Instruction fault at %#010lx\n", fp->ptregs.pc);
618 	buserr:
619 		pr_err("BAD KERNEL BUSERR\n");
620 		die_if_kernel("Oops",&fp->ptregs,0);
621 		force_sig(SIGKILL);
622 		return;
623 	}
624 
625 	/* get the fault address */
626 	if (fp->ptregs.format == 10)
627 		addr = fp->ptregs.pc + 4;
628 	else
629 		addr = fp->un.fmtb.baddr;
630 	if (ssw & FC)
631 		addr -= 2;
632 
633 	if ((ssw & DF) && ((addr ^ fp->un.fmtb.daddr) & PAGE_MASK) == 0)
634 		/* Insn fault on same page as data fault.  But we
635 		   should still create the ATC entry.  */
636 		goto create_atc_entry;
637 
638 #ifdef DEBUG
639 	asm volatile ("ptestr #1,%2@,#7,%0\n\t"
640 		      "pmove %%psr,%1"
641 		      : "=a&" (desc), "=m" (temp)
642 		      : "a" (addr));
643 	pr_debug("mmusr is %#x for addr %#lx in task %p\n",
644 		temp, addr, current);
645 	pr_debug("descriptor address is 0x%p, contents %#lx\n",
646 		__va(desc), *(unsigned long *)__va(desc));
647 #else
648 	asm volatile ("ptestr #1,%1@,#7\n\t"
649 		      "pmove %%psr,%0"
650 		      : "=m" (temp) : "a" (addr));
651 #endif
652 	mmusr = temp;
653 	if (mmusr & MMU_I)
654 		do_page_fault (&fp->ptregs, addr, 0);
655 	else if (mmusr & (MMU_B|MMU_L|MMU_S)) {
656 		pr_err("invalid insn access at %#lx from pc %#lx\n",
657 			addr, fp->ptregs.pc);
658 		pr_debug("Unknown SIGSEGV - 2\n");
659 		die_if_kernel("Oops",&fp->ptregs,mmusr);
660 		force_sig(SIGSEGV);
661 		return;
662 	}
663 
664 create_atc_entry:
665 	/* setup an ATC entry for the access about to be retried */
666 	asm volatile ("ploadr #2,%0@" : /* no outputs */
667 		      : "a" (addr));
668 }
669 #endif /* CPU_M68020_OR_M68030 */
670 #endif /* !CONFIG_SUN3 */
671 
672 #if defined(CONFIG_COLDFIRE) && defined(CONFIG_MMU)
673 #include <asm/mcfmmu.h>
674 
675 /*
676  *	The following table converts the FS encoding of a ColdFire
677  *	exception stack frame into the error_code value needed by
678  *	do_fault.
679 */
680 static const unsigned char fs_err_code[] = {
681 	0,  /* 0000 */
682 	0,  /* 0001 */
683 	0,  /* 0010 */
684 	0,  /* 0011 */
685 	1,  /* 0100 */
686 	0,  /* 0101 */
687 	0,  /* 0110 */
688 	0,  /* 0111 */
689 	2,  /* 1000 */
690 	3,  /* 1001 */
691 	2,  /* 1010 */
692 	0,  /* 1011 */
693 	1,  /* 1100 */
694 	1,  /* 1101 */
695 	0,  /* 1110 */
696 	0   /* 1111 */
697 };
698 
699 static inline void access_errorcf(unsigned int fs, struct frame *fp)
700 {
701 	unsigned long mmusr, addr;
702 	unsigned int err_code;
703 	int need_page_fault;
704 
705 	mmusr = mmu_read(MMUSR);
706 	addr = mmu_read(MMUAR);
707 
708 	/*
709 	 * error_code:
710 	 *	bit 0 == 0 means no page found, 1 means protection fault
711 	 *	bit 1 == 0 means read, 1 means write
712 	 */
713 	switch (fs) {
714 	case  5:  /* 0101 TLB opword X miss */
715 		need_page_fault = cf_tlb_miss(&fp->ptregs, 0, 0, 0);
716 		addr = fp->ptregs.pc;
717 		break;
718 	case  6:  /* 0110 TLB extension word X miss */
719 		need_page_fault = cf_tlb_miss(&fp->ptregs, 0, 0, 1);
720 		addr = fp->ptregs.pc + sizeof(long);
721 		break;
722 	case 10:  /* 1010 TLB W miss */
723 		need_page_fault = cf_tlb_miss(&fp->ptregs, 1, 1, 0);
724 		break;
725 	case 14: /* 1110 TLB R miss */
726 		need_page_fault = cf_tlb_miss(&fp->ptregs, 0, 1, 0);
727 		break;
728 	default:
729 		/* 0000 Normal  */
730 		/* 0001 Reserved */
731 		/* 0010 Interrupt during debug service routine */
732 		/* 0011 Reserved */
733 		/* 0100 X Protection */
734 		/* 0111 IFP in emulator mode */
735 		/* 1000 W Protection*/
736 		/* 1001 Write error*/
737 		/* 1011 Reserved*/
738 		/* 1100 R Protection*/
739 		/* 1101 R Protection*/
740 		/* 1111 OEP in emulator mode*/
741 		need_page_fault = 1;
742 		break;
743 	}
744 
745 	if (need_page_fault) {
746 		err_code = fs_err_code[fs];
747 		if ((fs == 13) && (mmusr & MMUSR_WF)) /* rd-mod-wr access */
748 			err_code |= 2; /* bit1 - write, bit0 - protection */
749 		do_page_fault(&fp->ptregs, addr, err_code);
750 	}
751 }
752 #endif /* CONFIG_COLDFIRE CONFIG_MMU */
753 
754 asmlinkage void buserr_c(struct frame *fp)
755 {
756 	/* Only set esp0 if coming from user mode */
757 	if (user_mode(&fp->ptregs))
758 		current->thread.esp0 = (unsigned long) fp;
759 
760 	pr_debug("*** Bus Error *** Format is %x\n", fp->ptregs.format);
761 
762 #if defined(CONFIG_COLDFIRE) && defined(CONFIG_MMU)
763 	if (CPU_IS_COLDFIRE) {
764 		unsigned int fs;
765 		fs = (fp->ptregs.vector & 0x3) |
766 			((fp->ptregs.vector & 0xc00) >> 8);
767 		switch (fs) {
768 		case 0x5:
769 		case 0x6:
770 		case 0x7:
771 		case 0x9:
772 		case 0xa:
773 		case 0xd:
774 		case 0xe:
775 		case 0xf:
776 			access_errorcf(fs, fp);
777 			return;
778 		default:
779 			break;
780 		}
781 	}
782 #endif /* CONFIG_COLDFIRE && CONFIG_MMU */
783 
784 	switch (fp->ptregs.format) {
785 #if defined (CONFIG_M68060)
786 	case 4:				/* 68060 access error */
787 	  access_error060 (fp);
788 	  break;
789 #endif
790 #if defined (CONFIG_M68040)
791 	case 0x7:			/* 68040 access error */
792 	  access_error040 (fp);
793 	  break;
794 #endif
795 #if defined (CPU_M68020_OR_M68030)
796 	case 0xa:
797 	case 0xb:
798 	  bus_error030 (fp);
799 	  break;
800 #endif
801 	default:
802 	  die_if_kernel("bad frame format",&fp->ptregs,0);
803 	  pr_debug("Unknown SIGSEGV - 4\n");
804 	  force_sig(SIGSEGV);
805 	}
806 }
807 
808 
809 static int kstack_depth_to_print = 48;
810 
811 static void show_trace(unsigned long *stack, const char *loglvl)
812 {
813 	unsigned long *endstack;
814 	unsigned long addr;
815 	int i;
816 
817 	printk("%sCall Trace:", loglvl);
818 	addr = (unsigned long)stack + THREAD_SIZE - 1;
819 	endstack = (unsigned long *)(addr & -THREAD_SIZE);
820 	i = 0;
821 	while (stack + 1 <= endstack) {
822 		addr = *stack++;
823 		/*
824 		 * If the address is either in the text segment of the
825 		 * kernel, or in the region which contains vmalloc'ed
826 		 * memory, it *may* be the address of a calling
827 		 * routine; if so, print it so that someone tracing
828 		 * down the cause of the crash will be able to figure
829 		 * out the call path that was taken.
830 		 */
831 		if (__kernel_text_address(addr)) {
832 #ifndef CONFIG_KALLSYMS
833 			if (i % 5 == 0)
834 				pr_cont("\n       ");
835 #endif
836 			pr_cont(" [<%08lx>] %pS\n", addr, (void *)addr);
837 			i++;
838 		}
839 	}
840 	pr_cont("\n");
841 }
842 
843 void show_registers(struct pt_regs *regs)
844 {
845 	struct frame *fp = (struct frame *)regs;
846 	u16 c, *cp;
847 	unsigned long addr;
848 	int i;
849 
850 	print_modules();
851 	pr_info("PC: [<%08lx>] %pS\n", regs->pc, (void *)regs->pc);
852 	pr_info("SR: %04x  SP: %p  a2: %08lx\n", regs->sr, regs, regs->a2);
853 	pr_info("d0: %08lx    d1: %08lx    d2: %08lx    d3: %08lx\n",
854 	       regs->d0, regs->d1, regs->d2, regs->d3);
855 	pr_info("d4: %08lx    d5: %08lx    a0: %08lx    a1: %08lx\n",
856 	       regs->d4, regs->d5, regs->a0, regs->a1);
857 
858 	pr_info("Process %s (pid: %d, task=%p)\n",
859 		current->comm, task_pid_nr(current), current);
860 	addr = (unsigned long)&fp->un;
861 	pr_info("Frame format=%X ", regs->format);
862 	switch (regs->format) {
863 	case 0x2:
864 		pr_cont("instr addr=%08lx\n", fp->un.fmt2.iaddr);
865 		addr += sizeof(fp->un.fmt2);
866 		break;
867 	case 0x3:
868 		pr_cont("eff addr=%08lx\n", fp->un.fmt3.effaddr);
869 		addr += sizeof(fp->un.fmt3);
870 		break;
871 	case 0x4:
872 		if (CPU_IS_060)
873 			pr_cont("fault addr=%08lx fslw=%08lx\n",
874 				fp->un.fmt4.effaddr, fp->un.fmt4.pc);
875 		else
876 			pr_cont("eff addr=%08lx pc=%08lx\n",
877 				fp->un.fmt4.effaddr, fp->un.fmt4.pc);
878 		addr += sizeof(fp->un.fmt4);
879 		break;
880 	case 0x7:
881 		pr_cont("eff addr=%08lx ssw=%04x faddr=%08lx\n",
882 			fp->un.fmt7.effaddr, fp->un.fmt7.ssw, fp->un.fmt7.faddr);
883 		pr_info("wb 1 stat/addr/data: %04x %08lx %08lx\n",
884 			fp->un.fmt7.wb1s, fp->un.fmt7.wb1a, fp->un.fmt7.wb1dpd0);
885 		pr_info("wb 2 stat/addr/data: %04x %08lx %08lx\n",
886 			fp->un.fmt7.wb2s, fp->un.fmt7.wb2a, fp->un.fmt7.wb2d);
887 		pr_info("wb 3 stat/addr/data: %04x %08lx %08lx\n",
888 			fp->un.fmt7.wb3s, fp->un.fmt7.wb3a, fp->un.fmt7.wb3d);
889 		pr_info("push data: %08lx %08lx %08lx %08lx\n",
890 			fp->un.fmt7.wb1dpd0, fp->un.fmt7.pd1, fp->un.fmt7.pd2,
891 			fp->un.fmt7.pd3);
892 		addr += sizeof(fp->un.fmt7);
893 		break;
894 	case 0x9:
895 		pr_cont("instr addr=%08lx\n", fp->un.fmt9.iaddr);
896 		addr += sizeof(fp->un.fmt9);
897 		break;
898 	case 0xa:
899 		pr_cont("ssw=%04x isc=%04x isb=%04x daddr=%08lx dobuf=%08lx\n",
900 			fp->un.fmta.ssw, fp->un.fmta.isc, fp->un.fmta.isb,
901 			fp->un.fmta.daddr, fp->un.fmta.dobuf);
902 		addr += sizeof(fp->un.fmta);
903 		break;
904 	case 0xb:
905 		pr_cont("ssw=%04x isc=%04x isb=%04x daddr=%08lx dobuf=%08lx\n",
906 			fp->un.fmtb.ssw, fp->un.fmtb.isc, fp->un.fmtb.isb,
907 			fp->un.fmtb.daddr, fp->un.fmtb.dobuf);
908 		pr_info("baddr=%08lx dibuf=%08lx ver=%x\n",
909 			fp->un.fmtb.baddr, fp->un.fmtb.dibuf, fp->un.fmtb.ver);
910 		addr += sizeof(fp->un.fmtb);
911 		break;
912 	default:
913 		pr_cont("\n");
914 	}
915 	show_stack(NULL, (unsigned long *)addr, KERN_INFO);
916 
917 	pr_info("Code:");
918 	cp = (u16 *)regs->pc;
919 	for (i = -8; i < 16; i++) {
920 		if (get_kernel_nofault(c, cp + i) && i >= 0) {
921 			pr_cont(" Bad PC value.");
922 			break;
923 		}
924 		if (i)
925 			pr_cont(" %04x", c);
926 		else
927 			pr_cont(" <%04x>", c);
928 	}
929 	pr_cont("\n");
930 }
931 
932 void show_stack(struct task_struct *task, unsigned long *stack,
933 		const char *loglvl)
934 {
935 	unsigned long *p;
936 	unsigned long *endstack;
937 	int i;
938 
939 	if (!stack) {
940 		if (task)
941 			stack = (unsigned long *)task->thread.esp0;
942 		else
943 			stack = (unsigned long *)&stack;
944 	}
945 	endstack = (unsigned long *)(((unsigned long)stack + THREAD_SIZE - 1) & -THREAD_SIZE);
946 
947 	printk("%sStack from %08lx:", loglvl, (unsigned long)stack);
948 	p = stack;
949 	for (i = 0; i < kstack_depth_to_print; i++) {
950 		if (p + 1 > endstack)
951 			break;
952 		if (i % 8 == 0)
953 			pr_cont("\n       ");
954 		pr_cont(" %08lx", *p++);
955 	}
956 	pr_cont("\n");
957 	show_trace(stack, loglvl);
958 }
959 
960 /*
961  * The vector number returned in the frame pointer may also contain
962  * the "fs" (Fault Status) bits on ColdFire. These are in the bottom
963  * 2 bits, and upper 2 bits. So we need to mask out the real vector
964  * number before using it in comparisons. You don't need to do this on
965  * real 68k parts, but it won't hurt either.
966  */
967 
968 void bad_super_trap (struct frame *fp)
969 {
970 	int vector = (fp->ptregs.vector >> 2) & 0xff;
971 
972 	console_verbose();
973 	if (vector < ARRAY_SIZE(vec_names))
974 		pr_err("*** %s ***   FORMAT=%X\n",
975 			vec_names[vector],
976 			fp->ptregs.format);
977 	else
978 		pr_err("*** Exception %d ***   FORMAT=%X\n",
979 			vector, fp->ptregs.format);
980 	if (vector == VEC_ADDRERR && CPU_IS_020_OR_030) {
981 		unsigned short ssw = fp->un.fmtb.ssw;
982 
983 		pr_err("SSW=%#06x  ", ssw);
984 
985 		if (ssw & RC)
986 			pr_err("Pipe stage C instruction fault at %#010lx\n",
987 				(fp->ptregs.format) == 0xA ?
988 				fp->ptregs.pc + 2 : fp->un.fmtb.baddr - 2);
989 		if (ssw & RB)
990 			pr_err("Pipe stage B instruction fault at %#010lx\n",
991 				(fp->ptregs.format) == 0xA ?
992 				fp->ptregs.pc + 4 : fp->un.fmtb.baddr);
993 		if (ssw & DF)
994 			pr_err("Data %s fault at %#010lx in %s (pc=%#lx)\n",
995 				ssw & RW ? "read" : "write",
996 				fp->un.fmtb.daddr, space_names[ssw & DFC],
997 				fp->ptregs.pc);
998 	}
999 	pr_err("Current process id is %d\n", task_pid_nr(current));
1000 	die_if_kernel("BAD KERNEL TRAP", &fp->ptregs, 0);
1001 }
1002 
1003 asmlinkage void trap_c(struct frame *fp)
1004 {
1005 	int sig, si_code;
1006 	void __user *addr;
1007 	int vector = (fp->ptregs.vector >> 2) & 0xff;
1008 
1009 	if (fp->ptregs.sr & PS_S) {
1010 		if (vector == VEC_TRACE) {
1011 			/* traced a trapping instruction on a 68020/30,
1012 			 * real exception will be executed afterwards.
1013 			 */
1014 			return;
1015 		}
1016 #ifdef CONFIG_MMU
1017 		if (fixup_exception(&fp->ptregs))
1018 			return;
1019 #endif
1020 		bad_super_trap(fp);
1021 		return;
1022 	}
1023 
1024 	/* send the appropriate signal to the user program */
1025 	switch (vector) {
1026 	    case VEC_ADDRERR:
1027 		si_code = BUS_ADRALN;
1028 		sig = SIGBUS;
1029 		break;
1030 	    case VEC_ILLEGAL:
1031 	    case VEC_LINE10:
1032 	    case VEC_LINE11:
1033 		si_code = ILL_ILLOPC;
1034 		sig = SIGILL;
1035 		break;
1036 	    case VEC_PRIV:
1037 		si_code = ILL_PRVOPC;
1038 		sig = SIGILL;
1039 		break;
1040 	    case VEC_COPROC:
1041 		si_code = ILL_COPROC;
1042 		sig = SIGILL;
1043 		break;
1044 	    case VEC_TRAP1:
1045 	    case VEC_TRAP2:
1046 	    case VEC_TRAP3:
1047 	    case VEC_TRAP4:
1048 	    case VEC_TRAP5:
1049 	    case VEC_TRAP6:
1050 	    case VEC_TRAP7:
1051 	    case VEC_TRAP8:
1052 	    case VEC_TRAP9:
1053 	    case VEC_TRAP10:
1054 	    case VEC_TRAP11:
1055 	    case VEC_TRAP12:
1056 	    case VEC_TRAP13:
1057 	    case VEC_TRAP14:
1058 		si_code = ILL_ILLTRP;
1059 		sig = SIGILL;
1060 		break;
1061 	    case VEC_FPBRUC:
1062 	    case VEC_FPOE:
1063 	    case VEC_FPNAN:
1064 		si_code = FPE_FLTINV;
1065 		sig = SIGFPE;
1066 		break;
1067 	    case VEC_FPIR:
1068 		si_code = FPE_FLTRES;
1069 		sig = SIGFPE;
1070 		break;
1071 	    case VEC_FPDIVZ:
1072 		si_code = FPE_FLTDIV;
1073 		sig = SIGFPE;
1074 		break;
1075 	    case VEC_FPUNDER:
1076 		si_code = FPE_FLTUND;
1077 		sig = SIGFPE;
1078 		break;
1079 	    case VEC_FPOVER:
1080 		si_code = FPE_FLTOVF;
1081 		sig = SIGFPE;
1082 		break;
1083 	    case VEC_ZERODIV:
1084 		si_code = FPE_INTDIV;
1085 		sig = SIGFPE;
1086 		break;
1087 	    case VEC_CHK:
1088 	    case VEC_TRAP:
1089 		si_code = FPE_INTOVF;
1090 		sig = SIGFPE;
1091 		break;
1092 	    case VEC_TRACE:		/* ptrace single step */
1093 		si_code = TRAP_TRACE;
1094 		sig = SIGTRAP;
1095 		break;
1096 	    case VEC_TRAP15:		/* breakpoint */
1097 		si_code = TRAP_BRKPT;
1098 		sig = SIGTRAP;
1099 		break;
1100 	    default:
1101 		si_code = ILL_ILLOPC;
1102 		sig = SIGILL;
1103 		break;
1104 	}
1105 	switch (fp->ptregs.format) {
1106 	    default:
1107 		addr = (void __user *) fp->ptregs.pc;
1108 		break;
1109 	    case 2:
1110 		addr = (void __user *) fp->un.fmt2.iaddr;
1111 		break;
1112 	    case 7:
1113 		addr = (void __user *) fp->un.fmt7.effaddr;
1114 		break;
1115 	    case 9:
1116 		addr = (void __user *) fp->un.fmt9.iaddr;
1117 		break;
1118 	    case 10:
1119 		addr = (void __user *) fp->un.fmta.daddr;
1120 		break;
1121 	    case 11:
1122 		addr = (void __user*) fp->un.fmtb.daddr;
1123 		break;
1124 	}
1125 	force_sig_fault(sig, si_code, addr);
1126 }
1127 
1128 void die_if_kernel (char *str, struct pt_regs *fp, int nr)
1129 {
1130 	if (!(fp->sr & PS_S))
1131 		return;
1132 
1133 	console_verbose();
1134 	pr_crit("%s: %08x\n", str, nr);
1135 	show_registers(fp);
1136 	add_taint(TAINT_DIE, LOCKDEP_NOW_UNRELIABLE);
1137 	make_task_dead(SIGSEGV);
1138 }
1139 
1140 asmlinkage void set_esp0(unsigned long ssp)
1141 {
1142 	current->thread.esp0 = ssp;
1143 }
1144 
1145 /*
1146  * This function is called if an error occur while accessing
1147  * user-space from the fpsp040 code.
1148  */
1149 asmlinkage void fpsp040_die(void)
1150 {
1151 	force_exit_sig(SIGSEGV);
1152 }
1153 
1154 #ifdef CONFIG_M68KFPU_EMU
1155 asmlinkage void fpemu_signal(int signal, int code, void *addr)
1156 {
1157 	force_sig_fault(signal, code, addr);
1158 }
1159 #endif
1160