Linux kernel mirror (for testing)
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linux
1/*
2 * OpenRISC traps.c
3 *
4 * Linux architectural port borrowing liberally from similar works of
5 * others. All original copyrights apply as per the original source
6 * declaration.
7 *
8 * Modifications for the OpenRISC architecture:
9 * Copyright (C) 2003 Matjaz Breskvar <phoenix@bsemi.com>
10 * Copyright (C) 2010-2011 Jonas Bonn <jonas@southpole.se>
11 *
12 * This program is free software; you can redistribute it and/or
13 * modify it under the terms of the GNU General Public License
14 * as published by the Free Software Foundation; either version
15 * 2 of the License, or (at your option) any later version.
16 *
17 * Here we handle the break vectors not used by the system call
18 * mechanism, as well as some general stack/register dumping
19 * things.
20 *
21 */
22
23#include <linux/init.h>
24#include <linux/sched.h>
25#include <linux/sched/debug.h>
26#include <linux/sched/task_stack.h>
27#include <linux/kernel.h>
28#include <linux/extable.h>
29#include <linux/kmod.h>
30#include <linux/string.h>
31#include <linux/errno.h>
32#include <linux/ptrace.h>
33#include <linux/timer.h>
34#include <linux/mm.h>
35#include <linux/kallsyms.h>
36#include <linux/uaccess.h>
37
38#include <asm/segment.h>
39#include <asm/io.h>
40#include <asm/pgtable.h>
41#include <asm/unwinder.h>
42#include <asm/sections.h>
43
44int kstack_depth_to_print = 0x180;
45int lwa_flag;
46unsigned long __user *lwa_addr;
47
48void print_trace(void *data, unsigned long addr, int reliable)
49{
50 pr_emerg("[<%p>] %s%pS\n", (void *) addr, reliable ? "" : "? ",
51 (void *) addr);
52}
53
54/* displays a short stack trace */
55void show_stack(struct task_struct *task, unsigned long *esp)
56{
57 if (esp == NULL)
58 esp = (unsigned long *)&esp;
59
60 pr_emerg("Call trace:\n");
61 unwind_stack(NULL, esp, print_trace);
62}
63
64void show_trace_task(struct task_struct *tsk)
65{
66 /*
67 * TODO: SysRq-T trace dump...
68 */
69}
70
71void show_registers(struct pt_regs *regs)
72{
73 int i;
74 int in_kernel = 1;
75 unsigned long esp;
76
77 esp = (unsigned long)(regs->sp);
78 if (user_mode(regs))
79 in_kernel = 0;
80
81 printk("CPU #: %d\n"
82 " PC: %08lx SR: %08lx SP: %08lx\n",
83 smp_processor_id(), regs->pc, regs->sr, regs->sp);
84 printk("GPR00: %08lx GPR01: %08lx GPR02: %08lx GPR03: %08lx\n",
85 0L, regs->gpr[1], regs->gpr[2], regs->gpr[3]);
86 printk("GPR04: %08lx GPR05: %08lx GPR06: %08lx GPR07: %08lx\n",
87 regs->gpr[4], regs->gpr[5], regs->gpr[6], regs->gpr[7]);
88 printk("GPR08: %08lx GPR09: %08lx GPR10: %08lx GPR11: %08lx\n",
89 regs->gpr[8], regs->gpr[9], regs->gpr[10], regs->gpr[11]);
90 printk("GPR12: %08lx GPR13: %08lx GPR14: %08lx GPR15: %08lx\n",
91 regs->gpr[12], regs->gpr[13], regs->gpr[14], regs->gpr[15]);
92 printk("GPR16: %08lx GPR17: %08lx GPR18: %08lx GPR19: %08lx\n",
93 regs->gpr[16], regs->gpr[17], regs->gpr[18], regs->gpr[19]);
94 printk("GPR20: %08lx GPR21: %08lx GPR22: %08lx GPR23: %08lx\n",
95 regs->gpr[20], regs->gpr[21], regs->gpr[22], regs->gpr[23]);
96 printk("GPR24: %08lx GPR25: %08lx GPR26: %08lx GPR27: %08lx\n",
97 regs->gpr[24], regs->gpr[25], regs->gpr[26], regs->gpr[27]);
98 printk("GPR28: %08lx GPR29: %08lx GPR30: %08lx GPR31: %08lx\n",
99 regs->gpr[28], regs->gpr[29], regs->gpr[30], regs->gpr[31]);
100 printk(" RES: %08lx oGPR11: %08lx\n",
101 regs->gpr[11], regs->orig_gpr11);
102
103 printk("Process %s (pid: %d, stackpage=%08lx)\n",
104 current->comm, current->pid, (unsigned long)current);
105 /*
106 * When in-kernel, we also print out the stack and code at the
107 * time of the fault..
108 */
109 if (in_kernel) {
110
111 printk("\nStack: ");
112 show_stack(NULL, (unsigned long *)esp);
113
114 printk("\nCode: ");
115 if (regs->pc < PAGE_OFFSET)
116 goto bad;
117
118 for (i = -24; i < 24; i++) {
119 unsigned char c;
120 if (__get_user(c, &((unsigned char *)regs->pc)[i])) {
121bad:
122 printk(" Bad PC value.");
123 break;
124 }
125
126 if (i == 0)
127 printk("(%02x) ", c);
128 else
129 printk("%02x ", c);
130 }
131 }
132 printk("\n");
133}
134
135void nommu_dump_state(struct pt_regs *regs,
136 unsigned long ea, unsigned long vector)
137{
138 int i;
139 unsigned long addr, stack = regs->sp;
140
141 printk("\n\r[nommu_dump_state] :: ea %lx, vector %lx\n\r", ea, vector);
142
143 printk("CPU #: %d\n"
144 " PC: %08lx SR: %08lx SP: %08lx\n",
145 0, regs->pc, regs->sr, regs->sp);
146 printk("GPR00: %08lx GPR01: %08lx GPR02: %08lx GPR03: %08lx\n",
147 0L, regs->gpr[1], regs->gpr[2], regs->gpr[3]);
148 printk("GPR04: %08lx GPR05: %08lx GPR06: %08lx GPR07: %08lx\n",
149 regs->gpr[4], regs->gpr[5], regs->gpr[6], regs->gpr[7]);
150 printk("GPR08: %08lx GPR09: %08lx GPR10: %08lx GPR11: %08lx\n",
151 regs->gpr[8], regs->gpr[9], regs->gpr[10], regs->gpr[11]);
152 printk("GPR12: %08lx GPR13: %08lx GPR14: %08lx GPR15: %08lx\n",
153 regs->gpr[12], regs->gpr[13], regs->gpr[14], regs->gpr[15]);
154 printk("GPR16: %08lx GPR17: %08lx GPR18: %08lx GPR19: %08lx\n",
155 regs->gpr[16], regs->gpr[17], regs->gpr[18], regs->gpr[19]);
156 printk("GPR20: %08lx GPR21: %08lx GPR22: %08lx GPR23: %08lx\n",
157 regs->gpr[20], regs->gpr[21], regs->gpr[22], regs->gpr[23]);
158 printk("GPR24: %08lx GPR25: %08lx GPR26: %08lx GPR27: %08lx\n",
159 regs->gpr[24], regs->gpr[25], regs->gpr[26], regs->gpr[27]);
160 printk("GPR28: %08lx GPR29: %08lx GPR30: %08lx GPR31: %08lx\n",
161 regs->gpr[28], regs->gpr[29], regs->gpr[30], regs->gpr[31]);
162 printk(" RES: %08lx oGPR11: %08lx\n",
163 regs->gpr[11], regs->orig_gpr11);
164
165 printk("Process %s (pid: %d, stackpage=%08lx)\n",
166 ((struct task_struct *)(__pa(current)))->comm,
167 ((struct task_struct *)(__pa(current)))->pid,
168 (unsigned long)current);
169
170 printk("\nStack: ");
171 printk("Stack dump [0x%08lx]:\n", (unsigned long)stack);
172 for (i = 0; i < kstack_depth_to_print; i++) {
173 if (((long)stack & (THREAD_SIZE - 1)) == 0)
174 break;
175 stack++;
176
177 printk("%lx :: sp + %02d: 0x%08lx\n", stack, i * 4,
178 *((unsigned long *)(__pa(stack))));
179 }
180 printk("\n");
181
182 printk("Call Trace: ");
183 i = 1;
184 while (((long)stack & (THREAD_SIZE - 1)) != 0) {
185 addr = *((unsigned long *)__pa(stack));
186 stack++;
187
188 if (kernel_text_address(addr)) {
189 if (i && ((i % 6) == 0))
190 printk("\n ");
191 printk(" [<%08lx>]", addr);
192 i++;
193 }
194 }
195 printk("\n");
196
197 printk("\nCode: ");
198
199 for (i = -24; i < 24; i++) {
200 unsigned char c;
201 c = ((unsigned char *)(__pa(regs->pc)))[i];
202
203 if (i == 0)
204 printk("(%02x) ", c);
205 else
206 printk("%02x ", c);
207 }
208 printk("\n");
209}
210
211/* This is normally the 'Oops' routine */
212void die(const char *str, struct pt_regs *regs, long err)
213{
214
215 console_verbose();
216 printk("\n%s#: %04lx\n", str, err & 0xffff);
217 show_registers(regs);
218#ifdef CONFIG_JUMP_UPON_UNHANDLED_EXCEPTION
219 printk("\n\nUNHANDLED_EXCEPTION: entering infinite loop\n");
220
221 /* shut down interrupts */
222 local_irq_disable();
223
224 __asm__ __volatile__("l.nop 1");
225 do {} while (1);
226#endif
227 do_exit(SIGSEGV);
228}
229
230/* This is normally the 'Oops' routine */
231void die_if_kernel(const char *str, struct pt_regs *regs, long err)
232{
233 if (user_mode(regs))
234 return;
235
236 die(str, regs, err);
237}
238
239void unhandled_exception(struct pt_regs *regs, int ea, int vector)
240{
241 printk("Unable to handle exception at EA =0x%x, vector 0x%x",
242 ea, vector);
243 die("Oops", regs, 9);
244}
245
246void __init trap_init(void)
247{
248 /* Nothing needs to be done */
249}
250
251asmlinkage void do_trap(struct pt_regs *regs, unsigned long address)
252{
253 force_sig_fault(SIGTRAP, TRAP_TRACE, (void __user *)address, current);
254
255 regs->pc += 4;
256}
257
258asmlinkage void do_unaligned_access(struct pt_regs *regs, unsigned long address)
259{
260 if (user_mode(regs)) {
261 /* Send a SIGBUS */
262 force_sig_fault(SIGBUS, BUS_ADRALN, (void __user *)address, current);
263 } else {
264 printk("KERNEL: Unaligned Access 0x%.8lx\n", address);
265 show_registers(regs);
266 die("Die:", regs, address);
267 }
268
269}
270
271asmlinkage void do_bus_fault(struct pt_regs *regs, unsigned long address)
272{
273 if (user_mode(regs)) {
274 /* Send a SIGBUS */
275 force_sig_fault(SIGBUS, BUS_ADRERR, (void __user *)address, current);
276 } else { /* Kernel mode */
277 printk("KERNEL: Bus error (SIGBUS) 0x%.8lx\n", address);
278 show_registers(regs);
279 die("Die:", regs, address);
280 }
281}
282
283static inline int in_delay_slot(struct pt_regs *regs)
284{
285#ifdef CONFIG_OPENRISC_NO_SPR_SR_DSX
286 /* No delay slot flag, do the old way */
287 unsigned int op, insn;
288
289 insn = *((unsigned int *)regs->pc);
290 op = insn >> 26;
291 switch (op) {
292 case 0x00: /* l.j */
293 case 0x01: /* l.jal */
294 case 0x03: /* l.bnf */
295 case 0x04: /* l.bf */
296 case 0x11: /* l.jr */
297 case 0x12: /* l.jalr */
298 return 1;
299 default:
300 return 0;
301 }
302#else
303 return mfspr(SPR_SR) & SPR_SR_DSX;
304#endif
305}
306
307static inline void adjust_pc(struct pt_regs *regs, unsigned long address)
308{
309 int displacement;
310 unsigned int rb, op, jmp;
311
312 if (unlikely(in_delay_slot(regs))) {
313 /* In delay slot, instruction at pc is a branch, simulate it */
314 jmp = *((unsigned int *)regs->pc);
315
316 displacement = sign_extend32(((jmp) & 0x3ffffff) << 2, 27);
317 rb = (jmp & 0x0000ffff) >> 11;
318 op = jmp >> 26;
319
320 switch (op) {
321 case 0x00: /* l.j */
322 regs->pc += displacement;
323 return;
324 case 0x01: /* l.jal */
325 regs->pc += displacement;
326 regs->gpr[9] = regs->pc + 8;
327 return;
328 case 0x03: /* l.bnf */
329 if (regs->sr & SPR_SR_F)
330 regs->pc += 8;
331 else
332 regs->pc += displacement;
333 return;
334 case 0x04: /* l.bf */
335 if (regs->sr & SPR_SR_F)
336 regs->pc += displacement;
337 else
338 regs->pc += 8;
339 return;
340 case 0x11: /* l.jr */
341 regs->pc = regs->gpr[rb];
342 return;
343 case 0x12: /* l.jalr */
344 regs->pc = regs->gpr[rb];
345 regs->gpr[9] = regs->pc + 8;
346 return;
347 default:
348 break;
349 }
350 } else {
351 regs->pc += 4;
352 }
353}
354
355static inline void simulate_lwa(struct pt_regs *regs, unsigned long address,
356 unsigned int insn)
357{
358 unsigned int ra, rd;
359 unsigned long value;
360 unsigned long orig_pc;
361 long imm;
362
363 const struct exception_table_entry *entry;
364
365 orig_pc = regs->pc;
366 adjust_pc(regs, address);
367
368 ra = (insn >> 16) & 0x1f;
369 rd = (insn >> 21) & 0x1f;
370 imm = (short)insn;
371 lwa_addr = (unsigned long __user *)(regs->gpr[ra] + imm);
372
373 if ((unsigned long)lwa_addr & 0x3) {
374 do_unaligned_access(regs, address);
375 return;
376 }
377
378 if (get_user(value, lwa_addr)) {
379 if (user_mode(regs)) {
380 force_sig(SIGSEGV, current);
381 return;
382 }
383
384 if ((entry = search_exception_tables(orig_pc))) {
385 regs->pc = entry->fixup;
386 return;
387 }
388
389 /* kernel access in kernel space, load it directly */
390 value = *((unsigned long *)lwa_addr);
391 }
392
393 lwa_flag = 1;
394 regs->gpr[rd] = value;
395}
396
397static inline void simulate_swa(struct pt_regs *regs, unsigned long address,
398 unsigned int insn)
399{
400 unsigned long __user *vaddr;
401 unsigned long orig_pc;
402 unsigned int ra, rb;
403 long imm;
404
405 const struct exception_table_entry *entry;
406
407 orig_pc = regs->pc;
408 adjust_pc(regs, address);
409
410 ra = (insn >> 16) & 0x1f;
411 rb = (insn >> 11) & 0x1f;
412 imm = (short)(((insn & 0x2200000) >> 10) | (insn & 0x7ff));
413 vaddr = (unsigned long __user *)(regs->gpr[ra] + imm);
414
415 if (!lwa_flag || vaddr != lwa_addr) {
416 regs->sr &= ~SPR_SR_F;
417 return;
418 }
419
420 if ((unsigned long)vaddr & 0x3) {
421 do_unaligned_access(regs, address);
422 return;
423 }
424
425 if (put_user(regs->gpr[rb], vaddr)) {
426 if (user_mode(regs)) {
427 force_sig(SIGSEGV, current);
428 return;
429 }
430
431 if ((entry = search_exception_tables(orig_pc))) {
432 regs->pc = entry->fixup;
433 return;
434 }
435
436 /* kernel access in kernel space, store it directly */
437 *((unsigned long *)vaddr) = regs->gpr[rb];
438 }
439
440 lwa_flag = 0;
441 regs->sr |= SPR_SR_F;
442}
443
444#define INSN_LWA 0x1b
445#define INSN_SWA 0x33
446
447asmlinkage void do_illegal_instruction(struct pt_regs *regs,
448 unsigned long address)
449{
450 unsigned int op;
451 unsigned int insn = *((unsigned int *)address);
452
453 op = insn >> 26;
454
455 switch (op) {
456 case INSN_LWA:
457 simulate_lwa(regs, address, insn);
458 return;
459
460 case INSN_SWA:
461 simulate_swa(regs, address, insn);
462 return;
463
464 default:
465 break;
466 }
467
468 if (user_mode(regs)) {
469 /* Send a SIGILL */
470 force_sig_fault(SIGILL, ILL_ILLOPC, (void __user *)address, current);
471 } else { /* Kernel mode */
472 printk("KERNEL: Illegal instruction (SIGILL) 0x%.8lx\n",
473 address);
474 show_registers(regs);
475 die("Die:", regs, address);
476 }
477}