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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
Linus Torvalds1da177e2005-04-16 15:20:36 -07002 * Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
3 *
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public License
6 * as published by the Free Software Foundation; either version
7 * 2 of the License, or (at your option) any later version.
8 *
9 * Modified by Cort Dougan (cort@cs.nmt.edu)
10 * and Paul Mackerras (paulus@cs.anu.edu.au)
11 */
12
13/*
14 * This file handles the architecture-dependent parts of hardware exceptions
15 */
16
17#include <linux/errno.h>
18#include <linux/sched.h>
19#include <linux/kernel.h>
20#include <linux/mm.h>
21#include <linux/stddef.h>
22#include <linux/unistd.h>
23#include <linux/ptrace.h>
24#include <linux/slab.h>
25#include <linux/user.h>
26#include <linux/a.out.h>
27#include <linux/interrupt.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070028#include <linux/init.h>
29#include <linux/module.h>
30#include <linux/prctl.h>
31
32#include <asm/pgtable.h>
33#include <asm/uaccess.h>
34#include <asm/system.h>
35#include <asm/io.h>
36#include <asm/reg.h>
37#include <asm/xmon.h>
David Gibsonf7f6f4f2005-10-19 14:53:32 +100038#include <asm/pmc.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070039
40#ifdef CONFIG_XMON
Paul Mackerrasfd582ec2005-10-11 22:08:12 +100041extern int xmon_bpt(struct pt_regs *regs);
42extern int xmon_sstep(struct pt_regs *regs);
43extern int xmon_iabr_match(struct pt_regs *regs);
44extern int xmon_dabr_match(struct pt_regs *regs);
45
Benjamin Herrenschmidt7b007de2005-11-07 16:43:44 +110046int (*debugger)(struct pt_regs *regs) = xmon;
Linus Torvalds1da177e2005-04-16 15:20:36 -070047int (*debugger_bpt)(struct pt_regs *regs) = xmon_bpt;
48int (*debugger_sstep)(struct pt_regs *regs) = xmon_sstep;
49int (*debugger_iabr_match)(struct pt_regs *regs) = xmon_iabr_match;
50int (*debugger_dabr_match)(struct pt_regs *regs) = xmon_dabr_match;
51void (*debugger_fault_handler)(struct pt_regs *regs);
52#else
53#ifdef CONFIG_KGDB
Benjamin Herrenschmidt7b007de2005-11-07 16:43:44 +110054int (*debugger)(struct pt_regs *regs);
Linus Torvalds1da177e2005-04-16 15:20:36 -070055int (*debugger_bpt)(struct pt_regs *regs);
56int (*debugger_sstep)(struct pt_regs *regs);
57int (*debugger_iabr_match)(struct pt_regs *regs);
58int (*debugger_dabr_match)(struct pt_regs *regs);
59void (*debugger_fault_handler)(struct pt_regs *regs);
60#else
61#define debugger(regs) do { } while (0)
62#define debugger_bpt(regs) 0
63#define debugger_sstep(regs) 0
64#define debugger_iabr_match(regs) 0
65#define debugger_dabr_match(regs) 0
66#define debugger_fault_handler ((void (*)(struct pt_regs *))0)
67#endif
68#endif
69
70/*
71 * Trap & Exception support
72 */
73
74DEFINE_SPINLOCK(die_lock);
75
Stephen Rothwelldc1c1ca2005-10-01 18:43:42 +100076int die(const char * str, struct pt_regs * fp, long err)
Linus Torvalds1da177e2005-04-16 15:20:36 -070077{
78 static int die_counter;
79 int nl = 0;
80 console_verbose();
81 spin_lock_irq(&die_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -070082 printk("Oops: %s, sig: %ld [#%d]\n", str, err, ++die_counter);
83#ifdef CONFIG_PREEMPT
84 printk("PREEMPT ");
85 nl = 1;
86#endif
87#ifdef CONFIG_SMP
88 printk("SMP NR_CPUS=%d ", NR_CPUS);
89 nl = 1;
90#endif
91 if (nl)
92 printk("\n");
93 show_regs(fp);
94 spin_unlock_irq(&die_lock);
95 /* do_exit() should take care of panic'ing from an interrupt
96 * context so we don't handle it here
97 */
98 do_exit(err);
99}
100
101void _exception(int signr, struct pt_regs *regs, int code, unsigned long addr)
102{
103 siginfo_t info;
104
105 if (!user_mode(regs)) {
106 debugger(regs);
107 die("Exception in kernel mode", regs, signr);
108 }
109 info.si_signo = signr;
110 info.si_errno = 0;
111 info.si_code = code;
112 info.si_addr = (void __user *) addr;
113 force_sig_info(signr, &info, current);
Paul Mackerrasbb0bb3b2005-09-10 21:13:11 +1000114
115 /*
116 * Init gets no signals that it doesn't have a handler for.
117 * That's all very well, but if it has caused a synchronous
118 * exception and we ignore the resulting signal, it will just
119 * generate the same exception over and over again and we get
120 * nowhere. Better to kill it and let the kernel panic.
121 */
122 if (current->pid == 1) {
123 __sighandler_t handler;
124
125 spin_lock_irq(&current->sighand->siglock);
126 handler = current->sighand->action[signr-1].sa.sa_handler;
127 spin_unlock_irq(&current->sighand->siglock);
128 if (handler == SIG_DFL) {
129 /* init has generated a synchronous exception
130 and it doesn't have a handler for the signal */
131 printk(KERN_CRIT "init has generated signal %d "
132 "but has no handler for it\n", signr);
133 do_exit(signr);
134 }
135 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700136}
137
138/*
139 * I/O accesses can cause machine checks on powermacs.
140 * Check if the NIP corresponds to the address of a sync
141 * instruction for which there is an entry in the exception
142 * table.
143 * Note that the 601 only takes a machine check on TEA
144 * (transfer error ack) signal assertion, and does not
145 * set any of the top 16 bits of SRR1.
146 * -- paulus.
147 */
148static inline int check_io_access(struct pt_regs *regs)
149{
Paul Mackerrasa7fdd902006-01-15 17:30:44 +1100150#if defined CONFIG_8xx
Linus Torvalds1da177e2005-04-16 15:20:36 -0700151 unsigned long msr = regs->msr;
152 const struct exception_table_entry *entry;
153 unsigned int *nip = (unsigned int *)regs->nip;
154
155 if (((msr & 0xffff0000) == 0 || (msr & (0x80000 | 0x40000)))
156 && (entry = search_exception_tables(regs->nip)) != NULL) {
157 /*
158 * Check that it's a sync instruction, or somewhere
159 * in the twi; isync; nop sequence that inb/inw/inl uses.
160 * As the address is in the exception table
161 * we should be able to read the instr there.
162 * For the debug message, we look at the preceding
163 * load or store.
164 */
165 if (*nip == 0x60000000) /* nop */
166 nip -= 2;
167 else if (*nip == 0x4c00012c) /* isync */
168 --nip;
Marcelo Tosatti55b63322005-11-05 14:06:24 -0200169 /* eieio from I/O string functions */
170 else if ((*nip) == 0x7c0006ac || *(nip+1) == 0x7c0006ac)
171 nip += 2;
172 if (*nip == 0x7c0004ac || (*nip >> 26) == 3 ||
173 (*(nip+1) >> 26) == 3) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700174 /* sync or twi */
175 unsigned int rb;
176
177 --nip;
178 rb = (*nip >> 11) & 0x1f;
179 printk(KERN_DEBUG "%s bad port %lx at %p\n",
180 (*nip & 0x100)? "OUT to": "IN from",
181 regs->gpr[rb] - _IO_BASE, nip);
182 regs->msr |= MSR_RI;
183 regs->nip = entry->fixup;
184 return 1;
185 }
186 }
Paul Mackerrasa7fdd902006-01-15 17:30:44 +1100187#endif /* CONFIG_8xx */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700188 return 0;
189}
190
191#if defined(CONFIG_4xx) || defined(CONFIG_BOOKE)
192/* On 4xx, the reason for the machine check or program exception
193 is in the ESR. */
194#define get_reason(regs) ((regs)->dsisr)
Kumar Gala33d9e9b2005-06-25 14:54:37 -0700195#ifndef CONFIG_FSL_BOOKE
Linus Torvalds1da177e2005-04-16 15:20:36 -0700196#define get_mc_reason(regs) ((regs)->dsisr)
197#else
198#define get_mc_reason(regs) (mfspr(SPRN_MCSR))
199#endif
Paul Mackerras443a8482005-05-01 08:58:40 -0700200#define REASON_FP ESR_FP
Kumar Gala33d9e9b2005-06-25 14:54:37 -0700201#define REASON_ILLEGAL (ESR_PIL | ESR_PUO)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700202#define REASON_PRIVILEGED ESR_PPR
203#define REASON_TRAP ESR_PTR
204
205/* single-step stuff */
206#define single_stepping(regs) (current->thread.dbcr0 & DBCR0_IC)
207#define clear_single_step(regs) (current->thread.dbcr0 &= ~DBCR0_IC)
208
209#else
210/* On non-4xx, the reason for the machine check or program
211 exception is in the MSR. */
212#define get_reason(regs) ((regs)->msr)
213#define get_mc_reason(regs) ((regs)->msr)
214#define REASON_FP 0x100000
215#define REASON_ILLEGAL 0x80000
216#define REASON_PRIVILEGED 0x40000
217#define REASON_TRAP 0x20000
218
219#define single_stepping(regs) ((regs)->msr & MSR_SE)
220#define clear_single_step(regs) ((regs)->msr &= ~MSR_SE)
221#endif
222
223/*
224 * This is "fall-back" implementation for configurations
225 * which don't provide platform-specific machine check info
226 */
227void __attribute__ ((weak))
228platform_machine_check(struct pt_regs *regs)
229{
230}
231
Stephen Rothwelldc1c1ca2005-10-01 18:43:42 +1000232void machine_check_exception(struct pt_regs *regs)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700233{
234 unsigned long reason = get_mc_reason(regs);
235
236 if (user_mode(regs)) {
237 regs->msr |= MSR_RI;
238 _exception(SIGBUS, regs, BUS_ADRERR, regs->nip);
239 return;
240 }
241
242#if defined(CONFIG_8xx) && defined(CONFIG_PCI)
243 /* the qspan pci read routines can cause machine checks -- Cort */
244 bad_page_fault(regs, regs->dar, SIGBUS);
245 return;
246#endif
247
248 if (debugger_fault_handler) {
249 debugger_fault_handler(regs);
250 regs->msr |= MSR_RI;
251 return;
252 }
253
254 if (check_io_access(regs))
255 return;
256
257#if defined(CONFIG_4xx) && !defined(CONFIG_440A)
258 if (reason & ESR_IMCP) {
259 printk("Instruction");
260 mtspr(SPRN_ESR, reason & ~ESR_IMCP);
261 } else
262 printk("Data");
263 printk(" machine check in kernel mode.\n");
264#elif defined(CONFIG_440A)
265 printk("Machine check in kernel mode.\n");
266 if (reason & ESR_IMCP){
267 printk("Instruction Synchronous Machine Check exception\n");
268 mtspr(SPRN_ESR, reason & ~ESR_IMCP);
269 }
270 else {
271 u32 mcsr = mfspr(SPRN_MCSR);
272 if (mcsr & MCSR_IB)
273 printk("Instruction Read PLB Error\n");
274 if (mcsr & MCSR_DRB)
275 printk("Data Read PLB Error\n");
276 if (mcsr & MCSR_DWB)
277 printk("Data Write PLB Error\n");
278 if (mcsr & MCSR_TLBP)
279 printk("TLB Parity Error\n");
280 if (mcsr & MCSR_ICP){
281 flush_instruction_cache();
282 printk("I-Cache Parity Error\n");
283 }
284 if (mcsr & MCSR_DCSP)
285 printk("D-Cache Search Parity Error\n");
286 if (mcsr & MCSR_DCFP)
287 printk("D-Cache Flush Parity Error\n");
288 if (mcsr & MCSR_IMPE)
289 printk("Machine Check exception is imprecise\n");
290
291 /* Clear MCSR */
292 mtspr(SPRN_MCSR, mcsr);
293 }
294#elif defined (CONFIG_E500)
295 printk("Machine check in kernel mode.\n");
296 printk("Caused by (from MCSR=%lx): ", reason);
297
298 if (reason & MCSR_MCP)
299 printk("Machine Check Signal\n");
300 if (reason & MCSR_ICPERR)
301 printk("Instruction Cache Parity Error\n");
302 if (reason & MCSR_DCP_PERR)
303 printk("Data Cache Push Parity Error\n");
304 if (reason & MCSR_DCPERR)
305 printk("Data Cache Parity Error\n");
306 if (reason & MCSR_GL_CI)
307 printk("Guarded Load or Cache-Inhibited stwcx.\n");
308 if (reason & MCSR_BUS_IAERR)
309 printk("Bus - Instruction Address Error\n");
310 if (reason & MCSR_BUS_RAERR)
311 printk("Bus - Read Address Error\n");
312 if (reason & MCSR_BUS_WAERR)
313 printk("Bus - Write Address Error\n");
314 if (reason & MCSR_BUS_IBERR)
315 printk("Bus - Instruction Data Error\n");
316 if (reason & MCSR_BUS_RBERR)
317 printk("Bus - Read Data Bus Error\n");
318 if (reason & MCSR_BUS_WBERR)
319 printk("Bus - Read Data Bus Error\n");
320 if (reason & MCSR_BUS_IPERR)
321 printk("Bus - Instruction Parity Error\n");
322 if (reason & MCSR_BUS_RPERR)
323 printk("Bus - Read Parity Error\n");
Kumar Gala33d9e9b2005-06-25 14:54:37 -0700324#elif defined (CONFIG_E200)
325 printk("Machine check in kernel mode.\n");
326 printk("Caused by (from MCSR=%lx): ", reason);
327
328 if (reason & MCSR_MCP)
329 printk("Machine Check Signal\n");
330 if (reason & MCSR_CP_PERR)
331 printk("Cache Push Parity Error\n");
332 if (reason & MCSR_CPERR)
333 printk("Cache Parity Error\n");
334 if (reason & MCSR_EXCP_ERR)
335 printk("ISI, ITLB, or Bus Error on first instruction fetch for an exception handler\n");
336 if (reason & MCSR_BUS_IRERR)
337 printk("Bus - Read Bus Error on instruction fetch\n");
338 if (reason & MCSR_BUS_DRERR)
339 printk("Bus - Read Bus Error on data load\n");
340 if (reason & MCSR_BUS_WRERR)
341 printk("Bus - Write Bus Error on buffered store or cache line push\n");
342#else /* !CONFIG_4xx && !CONFIG_E500 && !CONFIG_E200 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700343 printk("Machine check in kernel mode.\n");
344 printk("Caused by (from SRR1=%lx): ", reason);
345 switch (reason & 0x601F0000) {
346 case 0x80000:
347 printk("Machine check signal\n");
348 break;
349 case 0: /* for 601 */
350 case 0x40000:
351 case 0x140000: /* 7450 MSS error and TEA */
352 printk("Transfer error ack signal\n");
353 break;
354 case 0x20000:
355 printk("Data parity error signal\n");
356 break;
357 case 0x10000:
358 printk("Address parity error signal\n");
359 break;
360 case 0x20000000:
361 printk("L1 Data Cache error\n");
362 break;
363 case 0x40000000:
364 printk("L1 Instruction Cache error\n");
365 break;
366 case 0x00100000:
367 printk("L2 data cache parity error\n");
368 break;
369 default:
370 printk("Unknown values in msr\n");
371 }
372#endif /* CONFIG_4xx */
373
374 /*
375 * Optional platform-provided routine to print out
376 * additional info, e.g. bus error registers.
377 */
378 platform_machine_check(regs);
379
380 debugger(regs);
381 die("machine check", regs, SIGBUS);
382}
383
384void SMIException(struct pt_regs *regs)
385{
386 debugger(regs);
387#if !(defined(CONFIG_XMON) || defined(CONFIG_KGDB))
388 show_regs(regs);
389 panic("System Management Interrupt");
390#endif
391}
392
Stephen Rothwelldc1c1ca2005-10-01 18:43:42 +1000393void unknown_exception(struct pt_regs *regs)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700394{
395 printk("Bad trap at PC: %lx, MSR: %lx, vector=%lx %s\n",
396 regs->nip, regs->msr, regs->trap, print_tainted());
397 _exception(SIGTRAP, regs, 0, 0);
398}
399
Stephen Rothwelldc1c1ca2005-10-01 18:43:42 +1000400void instruction_breakpoint_exception(struct pt_regs *regs)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700401{
402 if (debugger_iabr_match(regs))
403 return;
404 _exception(SIGTRAP, regs, TRAP_BRKPT, 0);
405}
406
407void RunModeException(struct pt_regs *regs)
408{
409 _exception(SIGTRAP, regs, 0, 0);
410}
411
412/* Illegal instruction emulation support. Originally written to
413 * provide the PVR to user applications using the mfspr rd, PVR.
414 * Return non-zero if we can't emulate, or -EFAULT if the associated
415 * memory access caused an access fault. Return zero on success.
416 *
417 * There are a couple of ways to do this, either "decode" the instruction
418 * or directly match lots of bits. In this case, matching lots of
419 * bits is faster and easier.
420 *
421 */
422#define INST_MFSPR_PVR 0x7c1f42a6
423#define INST_MFSPR_PVR_MASK 0xfc1fffff
424
425#define INST_DCBA 0x7c0005ec
426#define INST_DCBA_MASK 0x7c0007fe
427
428#define INST_MCRXR 0x7c000400
429#define INST_MCRXR_MASK 0x7c0007fe
430
431#define INST_STRING 0x7c00042a
432#define INST_STRING_MASK 0x7c0007fe
433#define INST_STRING_GEN_MASK 0x7c00067e
434#define INST_LSWI 0x7c0004aa
435#define INST_LSWX 0x7c00042a
436#define INST_STSWI 0x7c0005aa
437#define INST_STSWX 0x7c00052a
438
439static int emulate_string_inst(struct pt_regs *regs, u32 instword)
440{
441 u8 rT = (instword >> 21) & 0x1f;
442 u8 rA = (instword >> 16) & 0x1f;
443 u8 NB_RB = (instword >> 11) & 0x1f;
444 u32 num_bytes;
Al Viro91de1ff2005-04-25 07:55:58 -0700445 unsigned long EA;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700446 int pos = 0;
447
448 /* Early out if we are an invalid form of lswx */
449 if ((instword & INST_STRING_MASK) == INST_LSWX)
Kumar Gala92b4dc12005-05-28 15:52:13 -0700450 if ((rT == rA) || (rT == NB_RB))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700451 return -EINVAL;
452
453 EA = (rA == 0) ? 0 : regs->gpr[rA];
454
455 switch (instword & INST_STRING_MASK) {
456 case INST_LSWX:
457 case INST_STSWX:
458 EA += NB_RB;
459 num_bytes = regs->xer & 0x7f;
460 break;
461 case INST_LSWI:
462 case INST_STSWI:
463 num_bytes = (NB_RB == 0) ? 32 : NB_RB;
464 break;
465 default:
466 return -EINVAL;
467 }
468
469 while (num_bytes != 0)
470 {
471 u8 val;
472 u32 shift = 8 * (3 - (pos & 0x3));
473
474 switch ((instword & INST_STRING_MASK)) {
475 case INST_LSWX:
476 case INST_LSWI:
477 if (get_user(val, (u8 __user *)EA))
478 return -EFAULT;
479 /* first time updating this reg,
480 * zero it out */
481 if (pos == 0)
482 regs->gpr[rT] = 0;
483 regs->gpr[rT] |= val << shift;
484 break;
485 case INST_STSWI:
486 case INST_STSWX:
487 val = regs->gpr[rT] >> shift;
488 if (put_user(val, (u8 __user *)EA))
489 return -EFAULT;
490 break;
491 }
492 /* move EA to next address */
493 EA += 1;
494 num_bytes--;
495
496 /* manage our position within the register */
497 if (++pos == 4) {
498 pos = 0;
499 if (++rT == 32)
500 rT = 0;
501 }
502 }
503
504 return 0;
505}
506
507static int emulate_instruction(struct pt_regs *regs)
508{
509 u32 instword;
510 u32 rd;
511
512 if (!user_mode(regs))
513 return -EINVAL;
514 CHECK_FULL_REGS(regs);
515
516 if (get_user(instword, (u32 __user *)(regs->nip)))
517 return -EFAULT;
518
519 /* Emulate the mfspr rD, PVR.
520 */
521 if ((instword & INST_MFSPR_PVR_MASK) == INST_MFSPR_PVR) {
522 rd = (instword >> 21) & 0x1f;
523 regs->gpr[rd] = mfspr(SPRN_PVR);
524 return 0;
525 }
526
527 /* Emulating the dcba insn is just a no-op. */
528 if ((instword & INST_DCBA_MASK) == INST_DCBA)
529 return 0;
530
531 /* Emulate the mcrxr insn. */
532 if ((instword & INST_MCRXR_MASK) == INST_MCRXR) {
533 int shift = (instword >> 21) & 0x1c;
534 unsigned long msk = 0xf0000000UL >> shift;
535
536 regs->ccr = (regs->ccr & ~msk) | ((regs->xer >> shift) & msk);
537 regs->xer &= ~0xf0000000UL;
538 return 0;
539 }
540
541 /* Emulate load/store string insn. */
542 if ((instword & INST_STRING_GEN_MASK) == INST_STRING)
543 return emulate_string_inst(regs, instword);
544
545 return -EINVAL;
546}
547
548/*
549 * After we have successfully emulated an instruction, we have to
550 * check if the instruction was being single-stepped, and if so,
551 * pretend we got a single-step exception. This was pointed out
552 * by Kumar Gala. -- paulus
553 */
554static void emulate_single_step(struct pt_regs *regs)
555{
556 if (single_stepping(regs)) {
557 clear_single_step(regs);
558 _exception(SIGTRAP, regs, TRAP_TRACE, 0);
559 }
560}
561
562/*
563 * Look through the list of trap instructions that are used for BUG(),
564 * BUG_ON() and WARN_ON() and see if we hit one. At this point we know
565 * that the exception was caused by a trap instruction of some kind.
566 * Returns 1 if we should continue (i.e. it was a WARN_ON) or 0
567 * otherwise.
568 */
569extern struct bug_entry __start___bug_table[], __stop___bug_table[];
570
571#ifndef CONFIG_MODULES
572#define module_find_bug(x) NULL
573#endif
574
Becky Bruce25433b12005-09-19 17:01:54 -0500575struct bug_entry *find_bug(unsigned long bugaddr)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700576{
577 struct bug_entry *bug;
578
579 for (bug = __start___bug_table; bug < __stop___bug_table; ++bug)
580 if (bugaddr == bug->bug_addr)
581 return bug;
582 return module_find_bug(bugaddr);
583}
584
585int check_bug_trap(struct pt_regs *regs)
586{
587 struct bug_entry *bug;
588 unsigned long addr;
589
590 if (regs->msr & MSR_PR)
591 return 0; /* not in kernel */
592 addr = regs->nip; /* address of trap instruction */
593 if (addr < PAGE_OFFSET)
594 return 0;
595 bug = find_bug(regs->nip);
596 if (bug == NULL)
597 return 0;
598 if (bug->line & BUG_WARNING_TRAP) {
599 /* this is a WARN_ON rather than BUG/BUG_ON */
600#ifdef CONFIG_XMON
Becky Bruce9122ee32005-11-02 10:52:52 -0600601 xmon_printf(KERN_ERR "Badness in %s at %s:%ld\n",
Linus Torvalds1da177e2005-04-16 15:20:36 -0700602 bug->function, bug->file,
603 bug->line & ~BUG_WARNING_TRAP);
604#endif /* CONFIG_XMON */
Becky Bruce9122ee32005-11-02 10:52:52 -0600605 printk(KERN_ERR "Badness in %s at %s:%ld\n",
Linus Torvalds1da177e2005-04-16 15:20:36 -0700606 bug->function, bug->file,
607 bug->line & ~BUG_WARNING_TRAP);
608 dump_stack();
609 return 1;
610 }
611#ifdef CONFIG_XMON
Becky Bruce9122ee32005-11-02 10:52:52 -0600612 xmon_printf(KERN_CRIT "kernel BUG in %s at %s:%ld!\n",
Linus Torvalds1da177e2005-04-16 15:20:36 -0700613 bug->function, bug->file, bug->line);
614 xmon(regs);
615#endif /* CONFIG_XMON */
Becky Bruce9122ee32005-11-02 10:52:52 -0600616 printk(KERN_CRIT "kernel BUG in %s at %s:%ld!\n",
Linus Torvalds1da177e2005-04-16 15:20:36 -0700617 bug->function, bug->file, bug->line);
618
619 return 0;
620}
621
Stephen Rothwelldc1c1ca2005-10-01 18:43:42 +1000622void program_check_exception(struct pt_regs *regs)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700623{
624 unsigned int reason = get_reason(regs);
625 extern int do_mathemu(struct pt_regs *regs);
626
627#ifdef CONFIG_MATH_EMULATION
628 /* (reason & REASON_ILLEGAL) would be the obvious thing here,
629 * but there seems to be a hardware bug on the 405GP (RevD)
630 * that means ESR is sometimes set incorrectly - either to
631 * ESR_DST (!?) or 0. In the process of chasing this with the
632 * hardware people - not sure if it can happen on any illegal
633 * instruction or only on FP instructions, whether there is a
634 * pattern to occurences etc. -dgibson 31/Mar/2003 */
635 if (!(reason & REASON_TRAP) && do_mathemu(regs) == 0) {
636 emulate_single_step(regs);
637 return;
638 }
639#endif /* CONFIG_MATH_EMULATION */
640
641 if (reason & REASON_FP) {
642 /* IEEE FP exception */
643 int code = 0;
644 u32 fpscr;
645
646 /* We must make sure the FP state is consistent with
647 * our MSR_FP in regs
648 */
649 preempt_disable();
650 if (regs->msr & MSR_FP)
651 giveup_fpu(current);
652 preempt_enable();
653
David Gibson25c8a782005-10-27 16:27:25 +1000654 fpscr = current->thread.fpscr.val;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700655 fpscr &= fpscr << 22; /* mask summary bits with enables */
656 if (fpscr & FPSCR_VX)
657 code = FPE_FLTINV;
658 else if (fpscr & FPSCR_OX)
659 code = FPE_FLTOVF;
660 else if (fpscr & FPSCR_UX)
661 code = FPE_FLTUND;
662 else if (fpscr & FPSCR_ZX)
663 code = FPE_FLTDIV;
664 else if (fpscr & FPSCR_XX)
665 code = FPE_FLTRES;
666 _exception(SIGFPE, regs, code, regs->nip);
667 return;
668 }
669
670 if (reason & REASON_TRAP) {
671 /* trap exception */
672 if (debugger_bpt(regs))
673 return;
674 if (check_bug_trap(regs)) {
675 regs->nip += 4;
676 return;
677 }
678 _exception(SIGTRAP, regs, TRAP_BRKPT, 0);
679 return;
680 }
681
682 /* Try to emulate it if we should. */
683 if (reason & (REASON_ILLEGAL | REASON_PRIVILEGED)) {
684 switch (emulate_instruction(regs)) {
685 case 0:
686 regs->nip += 4;
687 emulate_single_step(regs);
688 return;
689 case -EFAULT:
690 _exception(SIGSEGV, regs, SEGV_MAPERR, regs->nip);
691 return;
692 }
693 }
694
695 if (reason & REASON_PRIVILEGED)
696 _exception(SIGILL, regs, ILL_PRVOPC, regs->nip);
697 else
698 _exception(SIGILL, regs, ILL_ILLOPC, regs->nip);
699}
700
Stephen Rothwelldc1c1ca2005-10-01 18:43:42 +1000701void single_step_exception(struct pt_regs *regs)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700702{
703 regs->msr &= ~(MSR_SE | MSR_BE); /* Turn off 'trace' bits */
704 if (debugger_sstep(regs))
705 return;
706 _exception(SIGTRAP, regs, TRAP_TRACE, 0);
707}
708
Stephen Rothwelldc1c1ca2005-10-01 18:43:42 +1000709void alignment_exception(struct pt_regs *regs)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700710{
711 int fixed;
712
713 fixed = fix_alignment(regs);
714 if (fixed == 1) {
715 regs->nip += 4; /* skip over emulated instruction */
Paul Mackerras6c26e032005-04-16 15:24:17 -0700716 emulate_single_step(regs);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700717 return;
718 }
719 if (fixed == -EFAULT) {
720 /* fixed == -EFAULT means the operand address was bad */
721 if (user_mode(regs))
722 _exception(SIGSEGV, regs, SEGV_ACCERR, regs->dar);
723 else
724 bad_page_fault(regs, regs->dar, SIGSEGV);
725 return;
726 }
727 _exception(SIGBUS, regs, BUS_ADRALN, regs->dar);
728}
729
730void StackOverflow(struct pt_regs *regs)
731{
732 printk(KERN_CRIT "Kernel stack overflow in process %p, r1=%lx\n",
733 current, regs->gpr[1]);
734 debugger(regs);
735 show_regs(regs);
736 panic("kernel stack overflow");
737}
738
739void nonrecoverable_exception(struct pt_regs *regs)
740{
741 printk(KERN_ERR "Non-recoverable exception at PC=%lx MSR=%lx\n",
742 regs->nip, regs->msr);
743 debugger(regs);
744 die("nonrecoverable exception", regs, SIGKILL);
745}
746
747void trace_syscall(struct pt_regs *regs)
748{
749 printk("Task: %p(%d), PC: %08lX/%08lX, Syscall: %3ld, Result: %s%ld %s\n",
750 current, current->pid, regs->nip, regs->link, regs->gpr[0],
751 regs->ccr&0x10000000?"Error=":"", regs->gpr[3], print_tainted());
752}
753
754#ifdef CONFIG_8xx
755void SoftwareEmulation(struct pt_regs *regs)
756{
757 extern int do_mathemu(struct pt_regs *);
758 extern int Soft_emulate_8xx(struct pt_regs *);
759 int errcode;
760
761 CHECK_FULL_REGS(regs);
762
763 if (!user_mode(regs)) {
764 debugger(regs);
765 die("Kernel Mode Software FPU Emulation", regs, SIGFPE);
766 }
767
768#ifdef CONFIG_MATH_EMULATION
769 errcode = do_mathemu(regs);
770#else
771 errcode = Soft_emulate_8xx(regs);
772#endif
773 if (errcode) {
774 if (errcode > 0)
775 _exception(SIGFPE, regs, 0, 0);
776 else if (errcode == -EFAULT)
777 _exception(SIGSEGV, regs, 0, 0);
778 else
779 _exception(SIGILL, regs, ILL_ILLOPC, regs->nip);
780 } else
781 emulate_single_step(regs);
782}
783#endif /* CONFIG_8xx */
784
785#if defined(CONFIG_40x) || defined(CONFIG_BOOKE)
786
787void DebugException(struct pt_regs *regs, unsigned long debug_status)
788{
789 if (debug_status & DBSR_IC) { /* instruction completion */
790 regs->msr &= ~MSR_DE;
791 if (user_mode(regs)) {
792 current->thread.dbcr0 &= ~DBCR0_IC;
793 } else {
794 /* Disable instruction completion */
795 mtspr(SPRN_DBCR0, mfspr(SPRN_DBCR0) & ~DBCR0_IC);
796 /* Clear the instruction completion event */
797 mtspr(SPRN_DBSR, DBSR_IC);
798 if (debugger_sstep(regs))
799 return;
800 }
801 _exception(SIGTRAP, regs, TRAP_TRACE, 0);
802 }
803}
804#endif /* CONFIG_4xx || CONFIG_BOOKE */
805
806#if !defined(CONFIG_TAU_INT)
807void TAUException(struct pt_regs *regs)
808{
809 printk("TAU trap at PC: %lx, MSR: %lx, vector=%lx %s\n",
810 regs->nip, regs->msr, regs->trap, print_tainted());
811}
812#endif /* CONFIG_INT_TAU */
813
Paul Mackerrasfd582ec2005-10-11 22:08:12 +1000814/*
815 * FP unavailable trap from kernel - print a message, but let
816 * the task use FP in the kernel until it returns to user mode.
817 */
818void kernel_fp_unavailable_exception(struct pt_regs *regs)
819{
820 regs->msr |= MSR_FP;
821 printk(KERN_ERR "floating point used in kernel (task=%p, pc=%lx)\n",
822 current, regs->nip);
823}
824
Stephen Rothwelldc1c1ca2005-10-01 18:43:42 +1000825void altivec_unavailable_exception(struct pt_regs *regs)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700826{
827 static int kernel_altivec_count;
828
829#ifndef CONFIG_ALTIVEC
830 if (user_mode(regs)) {
831 /* A user program has executed an altivec instruction,
832 but this kernel doesn't support altivec. */
833 _exception(SIGILL, regs, ILL_ILLOPC, regs->nip);
834 return;
835 }
836#endif
837 /* The kernel has executed an altivec instruction without
838 first enabling altivec. Whinge but let it do it. */
839 if (++kernel_altivec_count < 10)
840 printk(KERN_ERR "AltiVec used in kernel (task=%p, pc=%lx)\n",
841 current, regs->nip);
842 regs->msr |= MSR_VEC;
843}
844
845#ifdef CONFIG_ALTIVEC
Stephen Rothwelldc1c1ca2005-10-01 18:43:42 +1000846void altivec_assist_exception(struct pt_regs *regs)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700847{
848 int err;
849
850 preempt_disable();
851 if (regs->msr & MSR_VEC)
852 giveup_altivec(current);
853 preempt_enable();
Paul Mackerrase378cc12005-04-16 15:24:17 -0700854 if (!user_mode(regs)) {
855 printk(KERN_ERR "altivec assist exception in kernel mode"
856 " at %lx\n", regs->nip);
857 debugger(regs);
858 die("altivec assist exception", regs, SIGFPE);
859 return;
860 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700861
862 err = emulate_altivec(regs);
863 if (err == 0) {
864 regs->nip += 4; /* skip emulated instruction */
865 emulate_single_step(regs);
866 return;
867 }
868
869 if (err == -EFAULT) {
870 /* got an error reading the instruction */
871 _exception(SIGSEGV, regs, SEGV_ACCERR, regs->nip);
872 } else {
873 /* didn't recognize the instruction */
874 /* XXX quick hack for now: set the non-Java bit in the VSCR */
875 printk(KERN_ERR "unrecognized altivec instruction "
876 "in %s at %lx\n", current->comm, regs->nip);
877 current->thread.vscr.u[3] |= 0x10000;
878 }
879}
880#endif /* CONFIG_ALTIVEC */
881
Marcelo Tosatti83f7da82005-09-09 13:01:45 -0700882#ifdef CONFIG_E500
Stephen Rothwelldc1c1ca2005-10-01 18:43:42 +1000883void performance_monitor_exception(struct pt_regs *regs)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700884{
885 perf_irq(regs);
886}
Marcelo Tosatti83f7da82005-09-09 13:01:45 -0700887#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700888
889#ifdef CONFIG_FSL_BOOKE
890void CacheLockingException(struct pt_regs *regs, unsigned long address,
891 unsigned long error_code)
892{
893 /* We treat cache locking instructions from the user
894 * as priv ops, in the future we could try to do
895 * something smarter
896 */
897 if (error_code & (ESR_DLK|ESR_ILK))
898 _exception(SIGILL, regs, ILL_PRVOPC, regs->nip);
899 return;
900}
901#endif /* CONFIG_FSL_BOOKE */
902
903#ifdef CONFIG_SPE
904void SPEFloatingPointException(struct pt_regs *regs)
905{
906 unsigned long spefscr;
907 int fpexc_mode;
908 int code = 0;
909
910 spefscr = current->thread.spefscr;
911 fpexc_mode = current->thread.fpexc_mode;
912
913 /* Hardware does not neccessarily set sticky
914 * underflow/overflow/invalid flags */
915 if ((spefscr & SPEFSCR_FOVF) && (fpexc_mode & PR_FP_EXC_OVF)) {
916 code = FPE_FLTOVF;
917 spefscr |= SPEFSCR_FOVFS;
918 }
919 else if ((spefscr & SPEFSCR_FUNF) && (fpexc_mode & PR_FP_EXC_UND)) {
920 code = FPE_FLTUND;
921 spefscr |= SPEFSCR_FUNFS;
922 }
923 else if ((spefscr & SPEFSCR_FDBZ) && (fpexc_mode & PR_FP_EXC_DIV))
924 code = FPE_FLTDIV;
925 else if ((spefscr & SPEFSCR_FINV) && (fpexc_mode & PR_FP_EXC_INV)) {
926 code = FPE_FLTINV;
927 spefscr |= SPEFSCR_FINVS;
928 }
929 else if ((spefscr & (SPEFSCR_FG | SPEFSCR_FX)) && (fpexc_mode & PR_FP_EXC_RES))
930 code = FPE_FLTRES;
931
932 current->thread.spefscr = spefscr;
933
934 _exception(SIGFPE, regs, code, regs->nip);
935 return;
936}
937#endif
938
Kumar Galaa2f40cc2005-09-03 15:55:33 -0700939#ifdef CONFIG_BOOKE_WDT
940/*
941 * Default handler for a Watchdog exception,
942 * spins until a reboot occurs
943 */
944void __attribute__ ((weak)) WatchdogHandler(struct pt_regs *regs)
945{
946 /* Generic WatchdogHandler, implement your own */
947 mtspr(SPRN_TCR, mfspr(SPRN_TCR)&(~TCR_WIE));
948 return;
949}
950
951void WatchdogException(struct pt_regs *regs)
952{
953 printk (KERN_EMERG "PowerPC Book-E Watchdog Exception\n");
954 WatchdogHandler(regs);
955}
956#endif
957
Linus Torvalds1da177e2005-04-16 15:20:36 -0700958void __init trap_init(void)
959{
960}