xref: /openbmc/linux/arch/m68k/kernel/traps.c (revision b737eecd)
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 
34 #include <asm/setup.h>
35 #include <asm/fpu.h>
36 #include <linux/uaccess.h>
37 #include <asm/traps.h>
38 #include <asm/machdep.h>
39 #include <asm/siginfo.h>
40 #include <asm/tlbflush.h>
41 
42 static const char *vec_names[] = {
43 	[VEC_RESETSP]	= "RESET SP",
44 	[VEC_RESETPC]	= "RESET PC",
45 	[VEC_BUSERR]	= "BUS ERROR",
46 	[VEC_ADDRERR]	= "ADDRESS ERROR",
47 	[VEC_ILLEGAL]	= "ILLEGAL INSTRUCTION",
48 	[VEC_ZERODIV]	= "ZERO DIVIDE",
49 	[VEC_CHK]	= "CHK",
50 	[VEC_TRAP]	= "TRAPcc",
51 	[VEC_PRIV]	= "PRIVILEGE VIOLATION",
52 	[VEC_TRACE]	= "TRACE",
53 	[VEC_LINE10]	= "LINE 1010",
54 	[VEC_LINE11]	= "LINE 1111",
55 	[VEC_RESV12]	= "UNASSIGNED RESERVED 12",
56 	[VEC_COPROC]	= "COPROCESSOR PROTOCOL VIOLATION",
57 	[VEC_FORMAT]	= "FORMAT ERROR",
58 	[VEC_UNINT]	= "UNINITIALIZED INTERRUPT",
59 	[VEC_RESV16]	= "UNASSIGNED RESERVED 16",
60 	[VEC_RESV17]	= "UNASSIGNED RESERVED 17",
61 	[VEC_RESV18]	= "UNASSIGNED RESERVED 18",
62 	[VEC_RESV19]	= "UNASSIGNED RESERVED 19",
63 	[VEC_RESV20]	= "UNASSIGNED RESERVED 20",
64 	[VEC_RESV21]	= "UNASSIGNED RESERVED 21",
65 	[VEC_RESV22]	= "UNASSIGNED RESERVED 22",
66 	[VEC_RESV23]	= "UNASSIGNED RESERVED 23",
67 	[VEC_SPUR]	= "SPURIOUS INTERRUPT",
68 	[VEC_INT1]	= "LEVEL 1 INT",
69 	[VEC_INT2]	= "LEVEL 2 INT",
70 	[VEC_INT3]	= "LEVEL 3 INT",
71 	[VEC_INT4]	= "LEVEL 4 INT",
72 	[VEC_INT5]	= "LEVEL 5 INT",
73 	[VEC_INT6]	= "LEVEL 6 INT",
74 	[VEC_INT7]	= "LEVEL 7 INT",
75 	[VEC_SYS]	= "SYSCALL",
76 	[VEC_TRAP1]	= "TRAP #1",
77 	[VEC_TRAP2]	= "TRAP #2",
78 	[VEC_TRAP3]	= "TRAP #3",
79 	[VEC_TRAP4]	= "TRAP #4",
80 	[VEC_TRAP5]	= "TRAP #5",
81 	[VEC_TRAP6]	= "TRAP #6",
82 	[VEC_TRAP7]	= "TRAP #7",
83 	[VEC_TRAP8]	= "TRAP #8",
84 	[VEC_TRAP9]	= "TRAP #9",
85 	[VEC_TRAP10]	= "TRAP #10",
86 	[VEC_TRAP11]	= "TRAP #11",
87 	[VEC_TRAP12]	= "TRAP #12",
88 	[VEC_TRAP13]	= "TRAP #13",
89 	[VEC_TRAP14]	= "TRAP #14",
90 	[VEC_TRAP15]	= "TRAP #15",
91 	[VEC_FPBRUC]	= "FPCP BSUN",
92 	[VEC_FPIR]	= "FPCP INEXACT",
93 	[VEC_FPDIVZ]	= "FPCP DIV BY 0",
94 	[VEC_FPUNDER]	= "FPCP UNDERFLOW",
95 	[VEC_FPOE]	= "FPCP OPERAND ERROR",
96 	[VEC_FPOVER]	= "FPCP OVERFLOW",
97 	[VEC_FPNAN]	= "FPCP SNAN",
98 	[VEC_FPUNSUP]	= "FPCP UNSUPPORTED OPERATION",
99 	[VEC_MMUCFG]	= "MMU CONFIGURATION ERROR",
100 	[VEC_MMUILL]	= "MMU ILLEGAL OPERATION ERROR",
101 	[VEC_MMUACC]	= "MMU ACCESS LEVEL VIOLATION ERROR",
102 	[VEC_RESV59]	= "UNASSIGNED RESERVED 59",
103 	[VEC_UNIMPEA]	= "UNASSIGNED RESERVED 60",
104 	[VEC_UNIMPII]	= "UNASSIGNED RESERVED 61",
105 	[VEC_RESV62]	= "UNASSIGNED RESERVED 62",
106 	[VEC_RESV63]	= "UNASSIGNED RESERVED 63",
107 };
108 
109 static const char *space_names[] = {
110 	[0]		= "Space 0",
111 	[USER_DATA]	= "User Data",
112 	[USER_PROGRAM]	= "User Program",
113 #ifndef CONFIG_SUN3
114 	[3]		= "Space 3",
115 #else
116 	[FC_CONTROL]	= "Control",
117 #endif
118 	[4]		= "Space 4",
119 	[SUPER_DATA]	= "Super Data",
120 	[SUPER_PROGRAM]	= "Super Program",
121 	[CPU_SPACE]	= "CPU"
122 };
123 
124 void die_if_kernel(char *,struct pt_regs *,int);
125 asmlinkage int do_page_fault(struct pt_regs *regs, unsigned long address,
126                              unsigned long error_code);
127 int send_fault_sig(struct pt_regs *regs);
128 
129 asmlinkage void trap_c(struct frame *fp);
130 
131 #if defined (CONFIG_M68060)
132 static inline void access_error060 (struct frame *fp)
133 {
134 	unsigned long fslw = fp->un.fmt4.pc; /* is really FSLW for access error */
135 
136 	pr_debug("fslw=%#lx, fa=%#lx\n", fslw, fp->un.fmt4.effaddr);
137 
138 	if (fslw & MMU060_BPE) {
139 		/* branch prediction error -> clear branch cache */
140 		__asm__ __volatile__ ("movec %/cacr,%/d0\n\t"
141 				      "orl   #0x00400000,%/d0\n\t"
142 				      "movec %/d0,%/cacr"
143 				      : : : "d0" );
144 		/* return if there's no other error */
145 		if (!(fslw & MMU060_ERR_BITS) && !(fslw & MMU060_SEE))
146 			return;
147 	}
148 
149 	if (fslw & (MMU060_DESC_ERR | MMU060_WP | MMU060_SP)) {
150 		unsigned long errorcode;
151 		unsigned long addr = fp->un.fmt4.effaddr;
152 
153 		if (fslw & MMU060_MA)
154 			addr = (addr + PAGE_SIZE - 1) & PAGE_MASK;
155 
156 		errorcode = 1;
157 		if (fslw & MMU060_DESC_ERR) {
158 			__flush_tlb040_one(addr);
159 			errorcode = 0;
160 		}
161 		if (fslw & MMU060_W)
162 			errorcode |= 2;
163 		pr_debug("errorcode = %ld\n", errorcode);
164 		do_page_fault(&fp->ptregs, addr, errorcode);
165 	} else if (fslw & (MMU060_SEE)){
166 		/* Software Emulation Error.
167 		 * fault during mem_read/mem_write in ifpsp060/os.S
168 		 */
169 		send_fault_sig(&fp->ptregs);
170 	} else if (!(fslw & (MMU060_RE|MMU060_WE)) ||
171 		   send_fault_sig(&fp->ptregs) > 0) {
172 		pr_err("pc=%#lx, fa=%#lx\n", fp->ptregs.pc,
173 		       fp->un.fmt4.effaddr);
174 		pr_err("68060 access error, fslw=%lx\n", fslw);
175 		trap_c( fp );
176 	}
177 }
178 #endif /* CONFIG_M68060 */
179 
180 #if defined (CONFIG_M68040)
181 static inline unsigned long probe040(int iswrite, unsigned long addr, int wbs)
182 {
183 	unsigned long mmusr;
184 	mm_segment_t old_fs = get_fs();
185 
186 	set_fs(MAKE_MM_SEG(wbs));
187 
188 	if (iswrite)
189 		asm volatile (".chip 68040; ptestw (%0); .chip 68k" : : "a" (addr));
190 	else
191 		asm volatile (".chip 68040; ptestr (%0); .chip 68k" : : "a" (addr));
192 
193 	asm volatile (".chip 68040; movec %%mmusr,%0; .chip 68k" : "=r" (mmusr));
194 
195 	set_fs(old_fs);
196 
197 	return mmusr;
198 }
199 
200 static inline int do_040writeback1(unsigned short wbs, unsigned long wba,
201 				   unsigned long wbd)
202 {
203 	int res = 0;
204 	mm_segment_t old_fs = get_fs();
205 
206 	/* set_fs can not be moved, otherwise put_user() may oops */
207 	set_fs(MAKE_MM_SEG(wbs));
208 
209 	switch (wbs & WBSIZ_040) {
210 	case BA_SIZE_BYTE:
211 		res = put_user(wbd & 0xff, (char __user *)wba);
212 		break;
213 	case BA_SIZE_WORD:
214 		res = put_user(wbd & 0xffff, (short __user *)wba);
215 		break;
216 	case BA_SIZE_LONG:
217 		res = put_user(wbd, (int __user *)wba);
218 		break;
219 	}
220 
221 	/* set_fs can not be moved, otherwise put_user() may oops */
222 	set_fs(old_fs);
223 
224 
225 	pr_debug("do_040writeback1, res=%d\n", res);
226 
227 	return res;
228 }
229 
230 /* after an exception in a writeback the stack frame corresponding
231  * to that exception is discarded, set a few bits in the old frame
232  * to simulate what it should look like
233  */
234 static inline void fix_xframe040(struct frame *fp, unsigned long wba, unsigned short wbs)
235 {
236 	fp->un.fmt7.faddr = wba;
237 	fp->un.fmt7.ssw = wbs & 0xff;
238 	if (wba != current->thread.faddr)
239 	    fp->un.fmt7.ssw |= MA_040;
240 }
241 
242 static inline void do_040writebacks(struct frame *fp)
243 {
244 	int res = 0;
245 #if 0
246 	if (fp->un.fmt7.wb1s & WBV_040)
247 		pr_err("access_error040: cannot handle 1st writeback. oops.\n");
248 #endif
249 
250 	if ((fp->un.fmt7.wb2s & WBV_040) &&
251 	    !(fp->un.fmt7.wb2s & WBTT_040)) {
252 		res = do_040writeback1(fp->un.fmt7.wb2s, fp->un.fmt7.wb2a,
253 				       fp->un.fmt7.wb2d);
254 		if (res)
255 			fix_xframe040(fp, fp->un.fmt7.wb2a, fp->un.fmt7.wb2s);
256 		else
257 			fp->un.fmt7.wb2s = 0;
258 	}
259 
260 	/* do the 2nd wb only if the first one was successful (except for a kernel wb) */
261 	if (fp->un.fmt7.wb3s & WBV_040 && (!res || fp->un.fmt7.wb3s & 4)) {
262 		res = do_040writeback1(fp->un.fmt7.wb3s, fp->un.fmt7.wb3a,
263 				       fp->un.fmt7.wb3d);
264 		if (res)
265 		    {
266 			fix_xframe040(fp, fp->un.fmt7.wb3a, fp->un.fmt7.wb3s);
267 
268 			fp->un.fmt7.wb2s = fp->un.fmt7.wb3s;
269 			fp->un.fmt7.wb3s &= (~WBV_040);
270 			fp->un.fmt7.wb2a = fp->un.fmt7.wb3a;
271 			fp->un.fmt7.wb2d = fp->un.fmt7.wb3d;
272 		    }
273 		else
274 			fp->un.fmt7.wb3s = 0;
275 	}
276 
277 	if (res)
278 		send_fault_sig(&fp->ptregs);
279 }
280 
281 /*
282  * called from sigreturn(), must ensure userspace code didn't
283  * manipulate exception frame to circumvent protection, then complete
284  * pending writebacks
285  * we just clear TM2 to turn it into a userspace access
286  */
287 asmlinkage void berr_040cleanup(struct frame *fp)
288 {
289 	fp->un.fmt7.wb2s &= ~4;
290 	fp->un.fmt7.wb3s &= ~4;
291 
292 	do_040writebacks(fp);
293 }
294 
295 static inline void access_error040(struct frame *fp)
296 {
297 	unsigned short ssw = fp->un.fmt7.ssw;
298 	unsigned long mmusr;
299 
300 	pr_debug("ssw=%#x, fa=%#lx\n", ssw, fp->un.fmt7.faddr);
301 	pr_debug("wb1s=%#x, wb2s=%#x, wb3s=%#x\n", fp->un.fmt7.wb1s,
302 		fp->un.fmt7.wb2s, fp->un.fmt7.wb3s);
303 	pr_debug("wb2a=%lx, wb3a=%lx, wb2d=%lx, wb3d=%lx\n",
304 		fp->un.fmt7.wb2a, fp->un.fmt7.wb3a,
305 		fp->un.fmt7.wb2d, fp->un.fmt7.wb3d);
306 
307 	if (ssw & ATC_040) {
308 		unsigned long addr = fp->un.fmt7.faddr;
309 		unsigned long errorcode;
310 
311 		/*
312 		 * The MMU status has to be determined AFTER the address
313 		 * has been corrected if there was a misaligned access (MA).
314 		 */
315 		if (ssw & MA_040)
316 			addr = (addr + 7) & -8;
317 
318 		/* MMU error, get the MMUSR info for this access */
319 		mmusr = probe040(!(ssw & RW_040), addr, ssw);
320 		pr_debug("mmusr = %lx\n", mmusr);
321 		errorcode = 1;
322 		if (!(mmusr & MMU_R_040)) {
323 			/* clear the invalid atc entry */
324 			__flush_tlb040_one(addr);
325 			errorcode = 0;
326 		}
327 
328 		/* despite what documentation seems to say, RMW
329 		 * accesses have always both the LK and RW bits set */
330 		if (!(ssw & RW_040) || (ssw & LK_040))
331 			errorcode |= 2;
332 
333 		if (do_page_fault(&fp->ptregs, addr, errorcode)) {
334 			pr_debug("do_page_fault() !=0\n");
335 			if (user_mode(&fp->ptregs)){
336 				/* delay writebacks after signal delivery */
337 				pr_debug(".. was usermode - return\n");
338 				return;
339 			}
340 			/* disable writeback into user space from kernel
341 			 * (if do_page_fault didn't fix the mapping,
342                          * the writeback won't do good)
343 			 */
344 disable_wb:
345 			pr_debug(".. disabling wb2\n");
346 			if (fp->un.fmt7.wb2a == fp->un.fmt7.faddr)
347 				fp->un.fmt7.wb2s &= ~WBV_040;
348 			if (fp->un.fmt7.wb3a == fp->un.fmt7.faddr)
349 				fp->un.fmt7.wb3s &= ~WBV_040;
350 		}
351 	} else {
352 		/* In case of a bus error we either kill the process or expect
353 		 * the kernel to catch the fault, which then is also responsible
354 		 * for cleaning up the mess.
355 		 */
356 		current->thread.signo = SIGBUS;
357 		current->thread.faddr = fp->un.fmt7.faddr;
358 		if (send_fault_sig(&fp->ptregs) >= 0)
359 			pr_err("68040 bus error (ssw=%x, faddr=%lx)\n", ssw,
360 			       fp->un.fmt7.faddr);
361 		goto disable_wb;
362 	}
363 
364 	do_040writebacks(fp);
365 }
366 #endif /* CONFIG_M68040 */
367 
368 #if defined(CONFIG_SUN3)
369 #include <asm/sun3mmu.h>
370 
371 extern int mmu_emu_handle_fault (unsigned long, int, int);
372 
373 /* sun3 version of bus_error030 */
374 
375 static inline void bus_error030 (struct frame *fp)
376 {
377 	unsigned char buserr_type = sun3_get_buserr ();
378 	unsigned long addr, errorcode;
379 	unsigned short ssw = fp->un.fmtb.ssw;
380 	extern unsigned long _sun3_map_test_start, _sun3_map_test_end;
381 
382 	if (ssw & (FC | FB))
383 		pr_debug("Instruction fault at %#010lx\n",
384 			ssw & FC ?
385 			fp->ptregs.format == 0xa ? fp->ptregs.pc + 2 : fp->un.fmtb.baddr - 2
386 			:
387 			fp->ptregs.format == 0xa ? fp->ptregs.pc + 4 : fp->un.fmtb.baddr);
388 	if (ssw & DF)
389 		pr_debug("Data %s fault at %#010lx in %s (pc=%#lx)\n",
390 			ssw & RW ? "read" : "write",
391 			fp->un.fmtb.daddr,
392 			space_names[ssw & DFC], fp->ptregs.pc);
393 
394 	/*
395 	 * Check if this page should be demand-mapped. This needs to go before
396 	 * the testing for a bad kernel-space access (demand-mapping applies
397 	 * to kernel accesses too).
398 	 */
399 
400 	if ((ssw & DF)
401 	    && (buserr_type & (SUN3_BUSERR_PROTERR | SUN3_BUSERR_INVALID))) {
402 		if (mmu_emu_handle_fault (fp->un.fmtb.daddr, ssw & RW, 0))
403 			return;
404 	}
405 
406 	/* Check for kernel-space pagefault (BAD). */
407 	if (fp->ptregs.sr & PS_S) {
408 		/* kernel fault must be a data fault to user space */
409 		if (! ((ssw & DF) && ((ssw & DFC) == USER_DATA))) {
410 		     // try checking the kernel mappings before surrender
411 		     if (mmu_emu_handle_fault (fp->un.fmtb.daddr, ssw & RW, 1))
412 			  return;
413 			/* instruction fault or kernel data fault! */
414 			if (ssw & (FC | FB))
415 				pr_err("Instruction fault at %#010lx\n",
416 					fp->ptregs.pc);
417 			if (ssw & DF) {
418 				/* was this fault incurred testing bus mappings? */
419 				if((fp->ptregs.pc >= (unsigned long)&_sun3_map_test_start) &&
420 				   (fp->ptregs.pc <= (unsigned long)&_sun3_map_test_end)) {
421 					send_fault_sig(&fp->ptregs);
422 					return;
423 				}
424 
425 				pr_err("Data %s fault at %#010lx in %s (pc=%#lx)\n",
426 					ssw & RW ? "read" : "write",
427 					fp->un.fmtb.daddr,
428 					space_names[ssw & DFC], fp->ptregs.pc);
429 			}
430 			pr_err("BAD KERNEL BUSERR\n");
431 
432 			die_if_kernel("Oops", &fp->ptregs,0);
433 			force_sig(SIGKILL);
434 			return;
435 		}
436 	} else {
437 		/* user fault */
438 		if (!(ssw & (FC | FB)) && !(ssw & DF))
439 			/* not an instruction fault or data fault! BAD */
440 			panic ("USER BUSERR w/o instruction or data fault");
441 	}
442 
443 
444 	/* First handle the data fault, if any.  */
445 	if (ssw & DF) {
446 		addr = fp->un.fmtb.daddr;
447 
448 // errorcode bit 0:	0 -> no page		1 -> protection fault
449 // errorcode bit 1:	0 -> read fault		1 -> write fault
450 
451 // (buserr_type & SUN3_BUSERR_PROTERR)	-> protection fault
452 // (buserr_type & SUN3_BUSERR_INVALID)	-> invalid page fault
453 
454 		if (buserr_type & SUN3_BUSERR_PROTERR)
455 			errorcode = 0x01;
456 		else if (buserr_type & SUN3_BUSERR_INVALID)
457 			errorcode = 0x00;
458 		else {
459 			pr_debug("*** unexpected busfault type=%#04x\n",
460 				 buserr_type);
461 			pr_debug("invalid %s access at %#lx from pc %#lx\n",
462 				 !(ssw & RW) ? "write" : "read", addr,
463 				 fp->ptregs.pc);
464 			die_if_kernel ("Oops", &fp->ptregs, buserr_type);
465 			force_sig (SIGBUS);
466 			return;
467 		}
468 
469 //todo: wtf is RM bit? --m
470 		if (!(ssw & RW) || ssw & RM)
471 			errorcode |= 0x02;
472 
473 		/* Handle page fault. */
474 		do_page_fault (&fp->ptregs, addr, errorcode);
475 
476 		/* Retry the data fault now. */
477 		return;
478 	}
479 
480 	/* Now handle the instruction fault. */
481 
482 	/* Get the fault address. */
483 	if (fp->ptregs.format == 0xA)
484 		addr = fp->ptregs.pc + 4;
485 	else
486 		addr = fp->un.fmtb.baddr;
487 	if (ssw & FC)
488 		addr -= 2;
489 
490 	if (buserr_type & SUN3_BUSERR_INVALID) {
491 		if (!mmu_emu_handle_fault(addr, 1, 0))
492 			do_page_fault (&fp->ptregs, addr, 0);
493        } else {
494 		pr_debug("protection fault on insn access (segv).\n");
495 		force_sig (SIGSEGV);
496        }
497 }
498 #else
499 #if defined(CPU_M68020_OR_M68030)
500 static inline void bus_error030 (struct frame *fp)
501 {
502 	volatile unsigned short temp;
503 	unsigned short mmusr;
504 	unsigned long addr, errorcode;
505 	unsigned short ssw = fp->un.fmtb.ssw;
506 #ifdef DEBUG
507 	unsigned long desc;
508 #endif
509 
510 	pr_debug("pid = %x  ", current->pid);
511 	pr_debug("SSW=%#06x  ", ssw);
512 
513 	if (ssw & (FC | FB))
514 		pr_debug("Instruction fault at %#010lx\n",
515 			ssw & FC ?
516 			fp->ptregs.format == 0xa ? fp->ptregs.pc + 2 : fp->un.fmtb.baddr - 2
517 			:
518 			fp->ptregs.format == 0xa ? fp->ptregs.pc + 4 : fp->un.fmtb.baddr);
519 	if (ssw & DF)
520 		pr_debug("Data %s fault at %#010lx in %s (pc=%#lx)\n",
521 			ssw & RW ? "read" : "write",
522 			fp->un.fmtb.daddr,
523 			space_names[ssw & DFC], fp->ptregs.pc);
524 
525 	/* ++andreas: If a data fault and an instruction fault happen
526 	   at the same time map in both pages.  */
527 
528 	/* First handle the data fault, if any.  */
529 	if (ssw & DF) {
530 		addr = fp->un.fmtb.daddr;
531 
532 #ifdef DEBUG
533 		asm volatile ("ptestr %3,%2@,#7,%0\n\t"
534 			      "pmove %%psr,%1"
535 			      : "=a&" (desc), "=m" (temp)
536 			      : "a" (addr), "d" (ssw));
537 		pr_debug("mmusr is %#x for addr %#lx in task %p\n",
538 			 temp, addr, current);
539 		pr_debug("descriptor address is 0x%p, contents %#lx\n",
540 			 __va(desc), *(unsigned long *)__va(desc));
541 #else
542 		asm volatile ("ptestr %2,%1@,#7\n\t"
543 			      "pmove %%psr,%0"
544 			      : "=m" (temp) : "a" (addr), "d" (ssw));
545 #endif
546 		mmusr = temp;
547 		errorcode = (mmusr & MMU_I) ? 0 : 1;
548 		if (!(ssw & RW) || (ssw & RM))
549 			errorcode |= 2;
550 
551 		if (mmusr & (MMU_I | MMU_WP)) {
552 			if (ssw & 4) {
553 				pr_err("Data %s fault at %#010lx in %s (pc=%#lx)\n",
554 				       ssw & RW ? "read" : "write",
555 				       fp->un.fmtb.daddr,
556 				       space_names[ssw & DFC], fp->ptregs.pc);
557 				goto buserr;
558 			}
559 			/* Don't try to do anything further if an exception was
560 			   handled. */
561 			if (do_page_fault (&fp->ptregs, addr, errorcode) < 0)
562 				return;
563 		} else if (!(mmusr & MMU_I)) {
564 			/* probably a 020 cas fault */
565 			if (!(ssw & RM) && send_fault_sig(&fp->ptregs) > 0)
566 				pr_err("unexpected bus error (%#x,%#x)\n", ssw,
567 				       mmusr);
568 		} else if (mmusr & (MMU_B|MMU_L|MMU_S)) {
569 			pr_err("invalid %s access at %#lx from pc %#lx\n",
570 			       !(ssw & RW) ? "write" : "read", addr,
571 			       fp->ptregs.pc);
572 			die_if_kernel("Oops",&fp->ptregs,mmusr);
573 			force_sig(SIGSEGV);
574 			return;
575 		} else {
576 #if 0
577 			static volatile long tlong;
578 #endif
579 
580 			pr_err("weird %s access at %#lx from pc %#lx (ssw is %#x)\n",
581 			       !(ssw & RW) ? "write" : "read", addr,
582 			       fp->ptregs.pc, ssw);
583 			asm volatile ("ptestr #1,%1@,#0\n\t"
584 				      "pmove %%psr,%0"
585 				      : "=m" (temp)
586 				      : "a" (addr));
587 			mmusr = temp;
588 
589 			pr_err("level 0 mmusr is %#x\n", mmusr);
590 #if 0
591 			asm volatile ("pmove %%tt0,%0"
592 				      : "=m" (tlong));
593 			pr_debug("tt0 is %#lx, ", tlong);
594 			asm volatile ("pmove %%tt1,%0"
595 				      : "=m" (tlong));
596 			pr_debug("tt1 is %#lx\n", tlong);
597 #endif
598 			pr_debug("Unknown SIGSEGV - 1\n");
599 			die_if_kernel("Oops",&fp->ptregs,mmusr);
600 			force_sig(SIGSEGV);
601 			return;
602 		}
603 
604 		/* setup an ATC entry for the access about to be retried */
605 		if (!(ssw & RW) || (ssw & RM))
606 			asm volatile ("ploadw %1,%0@" : /* no outputs */
607 				      : "a" (addr), "d" (ssw));
608 		else
609 			asm volatile ("ploadr %1,%0@" : /* no outputs */
610 				      : "a" (addr), "d" (ssw));
611 	}
612 
613 	/* Now handle the instruction fault. */
614 
615 	if (!(ssw & (FC|FB)))
616 		return;
617 
618 	if (fp->ptregs.sr & PS_S) {
619 		pr_err("Instruction fault at %#010lx\n", fp->ptregs.pc);
620 	buserr:
621 		pr_err("BAD KERNEL BUSERR\n");
622 		die_if_kernel("Oops",&fp->ptregs,0);
623 		force_sig(SIGKILL);
624 		return;
625 	}
626 
627 	/* get the fault address */
628 	if (fp->ptregs.format == 10)
629 		addr = fp->ptregs.pc + 4;
630 	else
631 		addr = fp->un.fmtb.baddr;
632 	if (ssw & FC)
633 		addr -= 2;
634 
635 	if ((ssw & DF) && ((addr ^ fp->un.fmtb.daddr) & PAGE_MASK) == 0)
636 		/* Insn fault on same page as data fault.  But we
637 		   should still create the ATC entry.  */
638 		goto create_atc_entry;
639 
640 #ifdef DEBUG
641 	asm volatile ("ptestr #1,%2@,#7,%0\n\t"
642 		      "pmove %%psr,%1"
643 		      : "=a&" (desc), "=m" (temp)
644 		      : "a" (addr));
645 	pr_debug("mmusr is %#x for addr %#lx in task %p\n",
646 		temp, addr, current);
647 	pr_debug("descriptor address is 0x%p, contents %#lx\n",
648 		__va(desc), *(unsigned long *)__va(desc));
649 #else
650 	asm volatile ("ptestr #1,%1@,#7\n\t"
651 		      "pmove %%psr,%0"
652 		      : "=m" (temp) : "a" (addr));
653 #endif
654 	mmusr = temp;
655 	if (mmusr & MMU_I)
656 		do_page_fault (&fp->ptregs, addr, 0);
657 	else if (mmusr & (MMU_B|MMU_L|MMU_S)) {
658 		pr_err("invalid insn access at %#lx from pc %#lx\n",
659 			addr, fp->ptregs.pc);
660 		pr_debug("Unknown SIGSEGV - 2\n");
661 		die_if_kernel("Oops",&fp->ptregs,mmusr);
662 		force_sig(SIGSEGV);
663 		return;
664 	}
665 
666 create_atc_entry:
667 	/* setup an ATC entry for the access about to be retried */
668 	asm volatile ("ploadr #2,%0@" : /* no outputs */
669 		      : "a" (addr));
670 }
671 #endif /* CPU_M68020_OR_M68030 */
672 #endif /* !CONFIG_SUN3 */
673 
674 #if defined(CONFIG_COLDFIRE) && defined(CONFIG_MMU)
675 #include <asm/mcfmmu.h>
676 
677 /*
678  *	The following table converts the FS encoding of a ColdFire
679  *	exception stack frame into the error_code value needed by
680  *	do_fault.
681 */
682 static const unsigned char fs_err_code[] = {
683 	0,  /* 0000 */
684 	0,  /* 0001 */
685 	0,  /* 0010 */
686 	0,  /* 0011 */
687 	1,  /* 0100 */
688 	0,  /* 0101 */
689 	0,  /* 0110 */
690 	0,  /* 0111 */
691 	2,  /* 1000 */
692 	3,  /* 1001 */
693 	2,  /* 1010 */
694 	0,  /* 1011 */
695 	1,  /* 1100 */
696 	1,  /* 1101 */
697 	0,  /* 1110 */
698 	0   /* 1111 */
699 };
700 
701 static inline void access_errorcf(unsigned int fs, struct frame *fp)
702 {
703 	unsigned long mmusr, addr;
704 	unsigned int err_code;
705 	int need_page_fault;
706 
707 	mmusr = mmu_read(MMUSR);
708 	addr = mmu_read(MMUAR);
709 
710 	/*
711 	 * error_code:
712 	 *	bit 0 == 0 means no page found, 1 means protection fault
713 	 *	bit 1 == 0 means read, 1 means write
714 	 */
715 	switch (fs) {
716 	case  5:  /* 0101 TLB opword X miss */
717 		need_page_fault = cf_tlb_miss(&fp->ptregs, 0, 0, 0);
718 		addr = fp->ptregs.pc;
719 		break;
720 	case  6:  /* 0110 TLB extension word X miss */
721 		need_page_fault = cf_tlb_miss(&fp->ptregs, 0, 0, 1);
722 		addr = fp->ptregs.pc + sizeof(long);
723 		break;
724 	case 10:  /* 1010 TLB W miss */
725 		need_page_fault = cf_tlb_miss(&fp->ptregs, 1, 1, 0);
726 		break;
727 	case 14: /* 1110 TLB R miss */
728 		need_page_fault = cf_tlb_miss(&fp->ptregs, 0, 1, 0);
729 		break;
730 	default:
731 		/* 0000 Normal  */
732 		/* 0001 Reserved */
733 		/* 0010 Interrupt during debug service routine */
734 		/* 0011 Reserved */
735 		/* 0100 X Protection */
736 		/* 0111 IFP in emulator mode */
737 		/* 1000 W Protection*/
738 		/* 1001 Write error*/
739 		/* 1011 Reserved*/
740 		/* 1100 R Protection*/
741 		/* 1101 R Protection*/
742 		/* 1111 OEP in emulator mode*/
743 		need_page_fault = 1;
744 		break;
745 	}
746 
747 	if (need_page_fault) {
748 		err_code = fs_err_code[fs];
749 		if ((fs == 13) && (mmusr & MMUSR_WF)) /* rd-mod-wr access */
750 			err_code |= 2; /* bit1 - write, bit0 - protection */
751 		do_page_fault(&fp->ptregs, addr, err_code);
752 	}
753 }
754 #endif /* CONFIG_COLDFIRE CONFIG_MMU */
755 
756 asmlinkage void buserr_c(struct frame *fp)
757 {
758 	/* Only set esp0 if coming from user mode */
759 	if (user_mode(&fp->ptregs))
760 		current->thread.esp0 = (unsigned long) fp;
761 
762 	pr_debug("*** Bus Error *** Format is %x\n", fp->ptregs.format);
763 
764 #if defined(CONFIG_COLDFIRE) && defined(CONFIG_MMU)
765 	if (CPU_IS_COLDFIRE) {
766 		unsigned int fs;
767 		fs = (fp->ptregs.vector & 0x3) |
768 			((fp->ptregs.vector & 0xc00) >> 8);
769 		switch (fs) {
770 		case 0x5:
771 		case 0x6:
772 		case 0x7:
773 		case 0x9:
774 		case 0xa:
775 		case 0xd:
776 		case 0xe:
777 		case 0xf:
778 			access_errorcf(fs, fp);
779 			return;
780 		default:
781 			break;
782 		}
783 	}
784 #endif /* CONFIG_COLDFIRE && CONFIG_MMU */
785 
786 	switch (fp->ptregs.format) {
787 #if defined (CONFIG_M68060)
788 	case 4:				/* 68060 access error */
789 	  access_error060 (fp);
790 	  break;
791 #endif
792 #if defined (CONFIG_M68040)
793 	case 0x7:			/* 68040 access error */
794 	  access_error040 (fp);
795 	  break;
796 #endif
797 #if defined (CPU_M68020_OR_M68030)
798 	case 0xa:
799 	case 0xb:
800 	  bus_error030 (fp);
801 	  break;
802 #endif
803 	default:
804 	  die_if_kernel("bad frame format",&fp->ptregs,0);
805 	  pr_debug("Unknown SIGSEGV - 4\n");
806 	  force_sig(SIGSEGV);
807 	}
808 }
809 
810 
811 static int kstack_depth_to_print = 48;
812 
813 static void show_trace(unsigned long *stack, const char *loglvl)
814 {
815 	unsigned long *endstack;
816 	unsigned long addr;
817 	int i;
818 
819 	printk("%sCall Trace:", loglvl);
820 	addr = (unsigned long)stack + THREAD_SIZE - 1;
821 	endstack = (unsigned long *)(addr & -THREAD_SIZE);
822 	i = 0;
823 	while (stack + 1 <= endstack) {
824 		addr = *stack++;
825 		/*
826 		 * If the address is either in the text segment of the
827 		 * kernel, or in the region which contains vmalloc'ed
828 		 * memory, it *may* be the address of a calling
829 		 * routine; if so, print it so that someone tracing
830 		 * down the cause of the crash will be able to figure
831 		 * out the call path that was taken.
832 		 */
833 		if (__kernel_text_address(addr)) {
834 #ifndef CONFIG_KALLSYMS
835 			if (i % 5 == 0)
836 				pr_cont("\n       ");
837 #endif
838 			pr_cont(" [<%08lx>] %pS\n", addr, (void *)addr);
839 			i++;
840 		}
841 	}
842 	pr_cont("\n");
843 }
844 
845 void show_registers(struct pt_regs *regs)
846 {
847 	struct frame *fp = (struct frame *)regs;
848 	u16 c, *cp;
849 	unsigned long addr;
850 	int i;
851 
852 	print_modules();
853 	pr_info("PC: [<%08lx>] %pS\n", regs->pc, (void *)regs->pc);
854 	pr_info("SR: %04x  SP: %p  a2: %08lx\n", regs->sr, regs, regs->a2);
855 	pr_info("d0: %08lx    d1: %08lx    d2: %08lx    d3: %08lx\n",
856 	       regs->d0, regs->d1, regs->d2, regs->d3);
857 	pr_info("d4: %08lx    d5: %08lx    a0: %08lx    a1: %08lx\n",
858 	       regs->d4, regs->d5, regs->a0, regs->a1);
859 
860 	pr_info("Process %s (pid: %d, task=%p)\n",
861 		current->comm, task_pid_nr(current), current);
862 	addr = (unsigned long)&fp->un;
863 	pr_info("Frame format=%X ", regs->format);
864 	switch (regs->format) {
865 	case 0x2:
866 		pr_cont("instr addr=%08lx\n", fp->un.fmt2.iaddr);
867 		addr += sizeof(fp->un.fmt2);
868 		break;
869 	case 0x3:
870 		pr_cont("eff addr=%08lx\n", fp->un.fmt3.effaddr);
871 		addr += sizeof(fp->un.fmt3);
872 		break;
873 	case 0x4:
874 		if (CPU_IS_060)
875 			pr_cont("fault addr=%08lx fslw=%08lx\n",
876 				fp->un.fmt4.effaddr, fp->un.fmt4.pc);
877 		else
878 			pr_cont("eff addr=%08lx pc=%08lx\n",
879 				fp->un.fmt4.effaddr, fp->un.fmt4.pc);
880 		addr += sizeof(fp->un.fmt4);
881 		break;
882 	case 0x7:
883 		pr_cont("eff addr=%08lx ssw=%04x faddr=%08lx\n",
884 			fp->un.fmt7.effaddr, fp->un.fmt7.ssw, fp->un.fmt7.faddr);
885 		pr_info("wb 1 stat/addr/data: %04x %08lx %08lx\n",
886 			fp->un.fmt7.wb1s, fp->un.fmt7.wb1a, fp->un.fmt7.wb1dpd0);
887 		pr_info("wb 2 stat/addr/data: %04x %08lx %08lx\n",
888 			fp->un.fmt7.wb2s, fp->un.fmt7.wb2a, fp->un.fmt7.wb2d);
889 		pr_info("wb 3 stat/addr/data: %04x %08lx %08lx\n",
890 			fp->un.fmt7.wb3s, fp->un.fmt7.wb3a, fp->un.fmt7.wb3d);
891 		pr_info("push data: %08lx %08lx %08lx %08lx\n",
892 			fp->un.fmt7.wb1dpd0, fp->un.fmt7.pd1, fp->un.fmt7.pd2,
893 			fp->un.fmt7.pd3);
894 		addr += sizeof(fp->un.fmt7);
895 		break;
896 	case 0x9:
897 		pr_cont("instr addr=%08lx\n", fp->un.fmt9.iaddr);
898 		addr += sizeof(fp->un.fmt9);
899 		break;
900 	case 0xa:
901 		pr_cont("ssw=%04x isc=%04x isb=%04x daddr=%08lx dobuf=%08lx\n",
902 			fp->un.fmta.ssw, fp->un.fmta.isc, fp->un.fmta.isb,
903 			fp->un.fmta.daddr, fp->un.fmta.dobuf);
904 		addr += sizeof(fp->un.fmta);
905 		break;
906 	case 0xb:
907 		pr_cont("ssw=%04x isc=%04x isb=%04x daddr=%08lx dobuf=%08lx\n",
908 			fp->un.fmtb.ssw, fp->un.fmtb.isc, fp->un.fmtb.isb,
909 			fp->un.fmtb.daddr, fp->un.fmtb.dobuf);
910 		pr_info("baddr=%08lx dibuf=%08lx ver=%x\n",
911 			fp->un.fmtb.baddr, fp->un.fmtb.dibuf, fp->un.fmtb.ver);
912 		addr += sizeof(fp->un.fmtb);
913 		break;
914 	default:
915 		pr_cont("\n");
916 	}
917 	show_stack(NULL, (unsigned long *)addr, KERN_INFO);
918 
919 	pr_info("Code:");
920 	cp = (u16 *)regs->pc;
921 	for (i = -8; i < 16; i++) {
922 		if (get_kernel_nofault(c, cp + i) && i >= 0) {
923 			pr_cont(" Bad PC value.");
924 			break;
925 		}
926 		if (i)
927 			pr_cont(" %04x", c);
928 		else
929 			pr_cont(" <%04x>", c);
930 	}
931 	pr_cont("\n");
932 }
933 
934 void show_stack(struct task_struct *task, unsigned long *stack,
935 		const char *loglvl)
936 {
937 	unsigned long *p;
938 	unsigned long *endstack;
939 	int i;
940 
941 	if (!stack) {
942 		if (task)
943 			stack = (unsigned long *)task->thread.esp0;
944 		else
945 			stack = (unsigned long *)&stack;
946 	}
947 	endstack = (unsigned long *)(((unsigned long)stack + THREAD_SIZE - 1) & -THREAD_SIZE);
948 
949 	printk("%sStack from %08lx:", loglvl, (unsigned long)stack);
950 	p = stack;
951 	for (i = 0; i < kstack_depth_to_print; i++) {
952 		if (p + 1 > endstack)
953 			break;
954 		if (i % 8 == 0)
955 			pr_cont("\n       ");
956 		pr_cont(" %08lx", *p++);
957 	}
958 	pr_cont("\n");
959 	show_trace(stack, loglvl);
960 }
961 
962 /*
963  * The vector number returned in the frame pointer may also contain
964  * the "fs" (Fault Status) bits on ColdFire. These are in the bottom
965  * 2 bits, and upper 2 bits. So we need to mask out the real vector
966  * number before using it in comparisons. You don't need to do this on
967  * real 68k parts, but it won't hurt either.
968  */
969 
970 void bad_super_trap (struct frame *fp)
971 {
972 	int vector = (fp->ptregs.vector >> 2) & 0xff;
973 
974 	console_verbose();
975 	if (vector < ARRAY_SIZE(vec_names))
976 		pr_err("*** %s ***   FORMAT=%X\n",
977 			vec_names[vector],
978 			fp->ptregs.format);
979 	else
980 		pr_err("*** Exception %d ***   FORMAT=%X\n",
981 			vector, fp->ptregs.format);
982 	if (vector == VEC_ADDRERR && CPU_IS_020_OR_030) {
983 		unsigned short ssw = fp->un.fmtb.ssw;
984 
985 		pr_err("SSW=%#06x  ", ssw);
986 
987 		if (ssw & RC)
988 			pr_err("Pipe stage C instruction fault at %#010lx\n",
989 				(fp->ptregs.format) == 0xA ?
990 				fp->ptregs.pc + 2 : fp->un.fmtb.baddr - 2);
991 		if (ssw & RB)
992 			pr_err("Pipe stage B instruction fault at %#010lx\n",
993 				(fp->ptregs.format) == 0xA ?
994 				fp->ptregs.pc + 4 : fp->un.fmtb.baddr);
995 		if (ssw & DF)
996 			pr_err("Data %s fault at %#010lx in %s (pc=%#lx)\n",
997 				ssw & RW ? "read" : "write",
998 				fp->un.fmtb.daddr, space_names[ssw & DFC],
999 				fp->ptregs.pc);
1000 	}
1001 	pr_err("Current process id is %d\n", task_pid_nr(current));
1002 	die_if_kernel("BAD KERNEL TRAP", &fp->ptregs, 0);
1003 }
1004 
1005 asmlinkage void trap_c(struct frame *fp)
1006 {
1007 	int sig, si_code;
1008 	void __user *addr;
1009 	int vector = (fp->ptregs.vector >> 2) & 0xff;
1010 
1011 	if (fp->ptregs.sr & PS_S) {
1012 		if (vector == VEC_TRACE) {
1013 			/* traced a trapping instruction on a 68020/30,
1014 			 * real exception will be executed afterwards.
1015 			 */
1016 			return;
1017 		}
1018 #ifdef CONFIG_MMU
1019 		if (fixup_exception(&fp->ptregs))
1020 			return;
1021 #endif
1022 		bad_super_trap(fp);
1023 		return;
1024 	}
1025 
1026 	/* send the appropriate signal to the user program */
1027 	switch (vector) {
1028 	    case VEC_ADDRERR:
1029 		si_code = BUS_ADRALN;
1030 		sig = SIGBUS;
1031 		break;
1032 	    case VEC_ILLEGAL:
1033 	    case VEC_LINE10:
1034 	    case VEC_LINE11:
1035 		si_code = ILL_ILLOPC;
1036 		sig = SIGILL;
1037 		break;
1038 	    case VEC_PRIV:
1039 		si_code = ILL_PRVOPC;
1040 		sig = SIGILL;
1041 		break;
1042 	    case VEC_COPROC:
1043 		si_code = ILL_COPROC;
1044 		sig = SIGILL;
1045 		break;
1046 	    case VEC_TRAP1:
1047 	    case VEC_TRAP2:
1048 	    case VEC_TRAP3:
1049 	    case VEC_TRAP4:
1050 	    case VEC_TRAP5:
1051 	    case VEC_TRAP6:
1052 	    case VEC_TRAP7:
1053 	    case VEC_TRAP8:
1054 	    case VEC_TRAP9:
1055 	    case VEC_TRAP10:
1056 	    case VEC_TRAP11:
1057 	    case VEC_TRAP12:
1058 	    case VEC_TRAP13:
1059 	    case VEC_TRAP14:
1060 		si_code = ILL_ILLTRP;
1061 		sig = SIGILL;
1062 		break;
1063 	    case VEC_FPBRUC:
1064 	    case VEC_FPOE:
1065 	    case VEC_FPNAN:
1066 		si_code = FPE_FLTINV;
1067 		sig = SIGFPE;
1068 		break;
1069 	    case VEC_FPIR:
1070 		si_code = FPE_FLTRES;
1071 		sig = SIGFPE;
1072 		break;
1073 	    case VEC_FPDIVZ:
1074 		si_code = FPE_FLTDIV;
1075 		sig = SIGFPE;
1076 		break;
1077 	    case VEC_FPUNDER:
1078 		si_code = FPE_FLTUND;
1079 		sig = SIGFPE;
1080 		break;
1081 	    case VEC_FPOVER:
1082 		si_code = FPE_FLTOVF;
1083 		sig = SIGFPE;
1084 		break;
1085 	    case VEC_ZERODIV:
1086 		si_code = FPE_INTDIV;
1087 		sig = SIGFPE;
1088 		break;
1089 	    case VEC_CHK:
1090 	    case VEC_TRAP:
1091 		si_code = FPE_INTOVF;
1092 		sig = SIGFPE;
1093 		break;
1094 	    case VEC_TRACE:		/* ptrace single step */
1095 		si_code = TRAP_TRACE;
1096 		sig = SIGTRAP;
1097 		break;
1098 	    case VEC_TRAP15:		/* breakpoint */
1099 		si_code = TRAP_BRKPT;
1100 		sig = SIGTRAP;
1101 		break;
1102 	    default:
1103 		si_code = ILL_ILLOPC;
1104 		sig = SIGILL;
1105 		break;
1106 	}
1107 	switch (fp->ptregs.format) {
1108 	    default:
1109 		addr = (void __user *) fp->ptregs.pc;
1110 		break;
1111 	    case 2:
1112 		addr = (void __user *) fp->un.fmt2.iaddr;
1113 		break;
1114 	    case 7:
1115 		addr = (void __user *) fp->un.fmt7.effaddr;
1116 		break;
1117 	    case 9:
1118 		addr = (void __user *) fp->un.fmt9.iaddr;
1119 		break;
1120 	    case 10:
1121 		addr = (void __user *) fp->un.fmta.daddr;
1122 		break;
1123 	    case 11:
1124 		addr = (void __user*) fp->un.fmtb.daddr;
1125 		break;
1126 	}
1127 	force_sig_fault(sig, si_code, addr);
1128 }
1129 
1130 void die_if_kernel (char *str, struct pt_regs *fp, int nr)
1131 {
1132 	if (!(fp->sr & PS_S))
1133 		return;
1134 
1135 	console_verbose();
1136 	pr_crit("%s: %08x\n", str, nr);
1137 	show_registers(fp);
1138 	add_taint(TAINT_DIE, LOCKDEP_NOW_UNRELIABLE);
1139 	do_exit(SIGSEGV);
1140 }
1141 
1142 asmlinkage void set_esp0(unsigned long ssp)
1143 {
1144 	current->thread.esp0 = ssp;
1145 }
1146 
1147 /*
1148  * This function is called if an error occur while accessing
1149  * user-space from the fpsp040 code.
1150  */
1151 asmlinkage void fpsp040_die(void)
1152 {
1153 	do_exit(SIGSEGV);
1154 }
1155 
1156 #ifdef CONFIG_M68KFPU_EMU
1157 asmlinkage void fpemu_signal(int signal, int code, void *addr)
1158 {
1159 	force_sig_fault(signal, code, addr);
1160 }
1161 #endif
1162