1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * OpenRISC traps.c
4 *
5 * Linux architectural port borrowing liberally from similar works of
6 * others. All original copyrights apply as per the original source
7 * declaration.
8 *
9 * Modifications for the OpenRISC architecture:
10 * Copyright (C) 2003 Matjaz Breskvar <phoenix@bsemi.com>
11 * Copyright (C) 2010-2011 Jonas Bonn <jonas@southpole.se>
12 *
13 * Here we handle the break vectors not used by the system call
14 * mechanism, as well as some general stack/register dumping
15 * things.
16 */
17
18 #include <linux/init.h>
19 #include <linux/sched.h>
20 #include <linux/sched/debug.h>
21 #include <linux/sched/task_stack.h>
22 #include <linux/kernel.h>
23 #include <linux/extable.h>
24 #include <linux/kmod.h>
25 #include <linux/string.h>
26 #include <linux/errno.h>
27 #include <linux/ptrace.h>
28 #include <linux/timer.h>
29 #include <linux/mm.h>
30 #include <linux/kallsyms.h>
31 #include <linux/uaccess.h>
32
33 #include <asm/io.h>
34 #include <asm/unwinder.h>
35 #include <asm/sections.h>
36
37 static int kstack_depth_to_print = 0x180;
38 int lwa_flag;
39 static unsigned long __user *lwa_addr;
40
print_trace(void * data,unsigned long addr,int reliable)41 static void print_trace(void *data, unsigned long addr, int reliable)
42 {
43 const char *loglvl = data;
44
45 printk("%s[<%p>] %s%pS\n", loglvl, (void *) addr, reliable ? "" : "? ",
46 (void *) addr);
47 }
48
print_data(unsigned long base_addr,unsigned long word,int i)49 static void print_data(unsigned long base_addr, unsigned long word, int i)
50 {
51 if (i == 0)
52 printk("(%08lx:)\t%08lx", base_addr + (i * 4), word);
53 else
54 printk(" %08lx:\t%08lx", base_addr + (i * 4), word);
55 }
56
57 /* displays a short stack trace */
show_stack(struct task_struct * task,unsigned long * esp,const char * loglvl)58 void show_stack(struct task_struct *task, unsigned long *esp, const char *loglvl)
59 {
60 if (esp == NULL)
61 esp = (unsigned long *)&esp;
62
63 printk("%sCall trace:\n", loglvl);
64 unwind_stack((void *)loglvl, esp, print_trace);
65 }
66
show_registers(struct pt_regs * regs)67 void show_registers(struct pt_regs *regs)
68 {
69 int i;
70 int in_kernel = 1;
71 unsigned long esp;
72
73 esp = (unsigned long)(regs->sp);
74 if (user_mode(regs))
75 in_kernel = 0;
76
77 printk("CPU #: %d\n"
78 " PC: %08lx SR: %08lx SP: %08lx\n",
79 smp_processor_id(), regs->pc, regs->sr, regs->sp);
80 printk("GPR00: %08lx GPR01: %08lx GPR02: %08lx GPR03: %08lx\n",
81 0L, regs->gpr[1], regs->gpr[2], regs->gpr[3]);
82 printk("GPR04: %08lx GPR05: %08lx GPR06: %08lx GPR07: %08lx\n",
83 regs->gpr[4], regs->gpr[5], regs->gpr[6], regs->gpr[7]);
84 printk("GPR08: %08lx GPR09: %08lx GPR10: %08lx GPR11: %08lx\n",
85 regs->gpr[8], regs->gpr[9], regs->gpr[10], regs->gpr[11]);
86 printk("GPR12: %08lx GPR13: %08lx GPR14: %08lx GPR15: %08lx\n",
87 regs->gpr[12], regs->gpr[13], regs->gpr[14], regs->gpr[15]);
88 printk("GPR16: %08lx GPR17: %08lx GPR18: %08lx GPR19: %08lx\n",
89 regs->gpr[16], regs->gpr[17], regs->gpr[18], regs->gpr[19]);
90 printk("GPR20: %08lx GPR21: %08lx GPR22: %08lx GPR23: %08lx\n",
91 regs->gpr[20], regs->gpr[21], regs->gpr[22], regs->gpr[23]);
92 printk("GPR24: %08lx GPR25: %08lx GPR26: %08lx GPR27: %08lx\n",
93 regs->gpr[24], regs->gpr[25], regs->gpr[26], regs->gpr[27]);
94 printk("GPR28: %08lx GPR29: %08lx GPR30: %08lx GPR31: %08lx\n",
95 regs->gpr[28], regs->gpr[29], regs->gpr[30], regs->gpr[31]);
96 printk(" RES: %08lx oGPR11: %08lx\n",
97 regs->gpr[11], regs->orig_gpr11);
98
99 printk("Process %s (pid: %d, stackpage=%08lx)\n",
100 current->comm, current->pid, (unsigned long)current);
101 /*
102 * When in-kernel, we also print out the stack and code at the
103 * time of the fault..
104 */
105 if (in_kernel) {
106
107 printk("\nStack: ");
108 show_stack(NULL, (unsigned long *)esp, KERN_EMERG);
109
110 if (esp < PAGE_OFFSET)
111 goto bad_stack;
112
113 printk("\n");
114 for (i = -8; i < 24; i += 1) {
115 unsigned long word;
116
117 if (__get_user(word, &((unsigned long *)esp)[i])) {
118 bad_stack:
119 printk(" Bad Stack value.");
120 break;
121 }
122
123 print_data(esp, word, i);
124 }
125
126 printk("\nCode: ");
127 if (regs->pc < PAGE_OFFSET)
128 goto bad;
129
130 for (i = -6; i < 6; i += 1) {
131 unsigned long word;
132
133 if (__get_user(word, &((unsigned long *)regs->pc)[i])) {
134 bad:
135 printk(" Bad PC value.");
136 break;
137 }
138
139 print_data(regs->pc, word, i);
140 }
141 }
142 printk("\n");
143 }
144
nommu_dump_state(struct pt_regs * regs,unsigned long ea,unsigned long vector)145 void nommu_dump_state(struct pt_regs *regs,
146 unsigned long ea, unsigned long vector)
147 {
148 int i;
149 unsigned long addr, stack = regs->sp;
150
151 printk("\n\r[nommu_dump_state] :: ea %lx, vector %lx\n\r", ea, vector);
152
153 printk("CPU #: %d\n"
154 " PC: %08lx SR: %08lx SP: %08lx\n",
155 0, regs->pc, regs->sr, regs->sp);
156 printk("GPR00: %08lx GPR01: %08lx GPR02: %08lx GPR03: %08lx\n",
157 0L, regs->gpr[1], regs->gpr[2], regs->gpr[3]);
158 printk("GPR04: %08lx GPR05: %08lx GPR06: %08lx GPR07: %08lx\n",
159 regs->gpr[4], regs->gpr[5], regs->gpr[6], regs->gpr[7]);
160 printk("GPR08: %08lx GPR09: %08lx GPR10: %08lx GPR11: %08lx\n",
161 regs->gpr[8], regs->gpr[9], regs->gpr[10], regs->gpr[11]);
162 printk("GPR12: %08lx GPR13: %08lx GPR14: %08lx GPR15: %08lx\n",
163 regs->gpr[12], regs->gpr[13], regs->gpr[14], regs->gpr[15]);
164 printk("GPR16: %08lx GPR17: %08lx GPR18: %08lx GPR19: %08lx\n",
165 regs->gpr[16], regs->gpr[17], regs->gpr[18], regs->gpr[19]);
166 printk("GPR20: %08lx GPR21: %08lx GPR22: %08lx GPR23: %08lx\n",
167 regs->gpr[20], regs->gpr[21], regs->gpr[22], regs->gpr[23]);
168 printk("GPR24: %08lx GPR25: %08lx GPR26: %08lx GPR27: %08lx\n",
169 regs->gpr[24], regs->gpr[25], regs->gpr[26], regs->gpr[27]);
170 printk("GPR28: %08lx GPR29: %08lx GPR30: %08lx GPR31: %08lx\n",
171 regs->gpr[28], regs->gpr[29], regs->gpr[30], regs->gpr[31]);
172 printk(" RES: %08lx oGPR11: %08lx\n",
173 regs->gpr[11], regs->orig_gpr11);
174
175 printk("Process %s (pid: %d, stackpage=%08lx)\n",
176 ((struct task_struct *)(__pa(current)))->comm,
177 ((struct task_struct *)(__pa(current)))->pid,
178 (unsigned long)current);
179
180 printk("\nStack: ");
181 printk("Stack dump [0x%08lx]:\n", (unsigned long)stack);
182 for (i = 0; i < kstack_depth_to_print; i++) {
183 if (((long)stack & (THREAD_SIZE - 1)) == 0)
184 break;
185 stack++;
186
187 printk("%lx :: sp + %02d: 0x%08lx\n", stack, i * 4,
188 *((unsigned long *)(__pa(stack))));
189 }
190 printk("\n");
191
192 printk("Call Trace: ");
193 i = 1;
194 while (((long)stack & (THREAD_SIZE - 1)) != 0) {
195 addr = *((unsigned long *)__pa(stack));
196 stack++;
197
198 if (kernel_text_address(addr)) {
199 if (i && ((i % 6) == 0))
200 printk("\n ");
201 printk(" [<%08lx>]", addr);
202 i++;
203 }
204 }
205 printk("\n");
206
207 printk("\nCode: ");
208
209 for (i = -24; i < 24; i++) {
210 unsigned long word;
211
212 word = ((unsigned long *)(__pa(regs->pc)))[i];
213
214 print_data(regs->pc, word, i);
215 }
216 printk("\n");
217 }
218
219 /* This is normally the 'Oops' routine */
die(const char * str,struct pt_regs * regs,long err)220 void __noreturn die(const char *str, struct pt_regs *regs, long err)
221 {
222
223 console_verbose();
224 printk("\n%s#: %04lx\n", str, err & 0xffff);
225 show_registers(regs);
226 #ifdef CONFIG_JUMP_UPON_UNHANDLED_EXCEPTION
227 printk("\n\nUNHANDLED_EXCEPTION: entering infinite loop\n");
228
229 /* shut down interrupts */
230 local_irq_disable();
231
232 __asm__ __volatile__("l.nop 1");
233 do {} while (1);
234 #endif
235 make_task_dead(SIGSEGV);
236 }
237
unhandled_exception(struct pt_regs * regs,int ea,int vector)238 asmlinkage void unhandled_exception(struct pt_regs *regs, int ea, int vector)
239 {
240 printk("Unable to handle exception at EA =0x%x, vector 0x%x",
241 ea, vector);
242 die("Oops", regs, 9);
243 }
244
do_trap(struct pt_regs * regs,unsigned long address)245 asmlinkage void do_trap(struct pt_regs *regs, unsigned long address)
246 {
247 force_sig_fault(SIGTRAP, TRAP_BRKPT, (void __user *)regs->pc);
248 }
249
do_unaligned_access(struct pt_regs * regs,unsigned long address)250 asmlinkage void do_unaligned_access(struct pt_regs *regs, unsigned long address)
251 {
252 if (user_mode(regs)) {
253 /* Send a SIGBUS */
254 force_sig_fault(SIGBUS, BUS_ADRALN, (void __user *)address);
255 } else {
256 printk("KERNEL: Unaligned Access 0x%.8lx\n", address);
257 show_registers(regs);
258 die("Die:", regs, address);
259 }
260
261 }
262
do_bus_fault(struct pt_regs * regs,unsigned long address)263 asmlinkage void do_bus_fault(struct pt_regs *regs, unsigned long address)
264 {
265 if (user_mode(regs)) {
266 /* Send a SIGBUS */
267 force_sig_fault(SIGBUS, BUS_ADRERR, (void __user *)address);
268 } else { /* Kernel mode */
269 printk("KERNEL: Bus error (SIGBUS) 0x%.8lx\n", address);
270 show_registers(regs);
271 die("Die:", regs, address);
272 }
273 }
274
in_delay_slot(struct pt_regs * regs)275 static inline int in_delay_slot(struct pt_regs *regs)
276 {
277 #ifdef CONFIG_OPENRISC_NO_SPR_SR_DSX
278 /* No delay slot flag, do the old way */
279 unsigned int op, insn;
280
281 insn = *((unsigned int *)regs->pc);
282 op = insn >> 26;
283 switch (op) {
284 case 0x00: /* l.j */
285 case 0x01: /* l.jal */
286 case 0x03: /* l.bnf */
287 case 0x04: /* l.bf */
288 case 0x11: /* l.jr */
289 case 0x12: /* l.jalr */
290 return 1;
291 default:
292 return 0;
293 }
294 #else
295 return mfspr(SPR_SR) & SPR_SR_DSX;
296 #endif
297 }
298
adjust_pc(struct pt_regs * regs,unsigned long address)299 static inline void adjust_pc(struct pt_regs *regs, unsigned long address)
300 {
301 int displacement;
302 unsigned int rb, op, jmp;
303
304 if (unlikely(in_delay_slot(regs))) {
305 /* In delay slot, instruction at pc is a branch, simulate it */
306 jmp = *((unsigned int *)regs->pc);
307
308 displacement = sign_extend32(((jmp) & 0x3ffffff) << 2, 27);
309 rb = (jmp & 0x0000ffff) >> 11;
310 op = jmp >> 26;
311
312 switch (op) {
313 case 0x00: /* l.j */
314 regs->pc += displacement;
315 return;
316 case 0x01: /* l.jal */
317 regs->pc += displacement;
318 regs->gpr[9] = regs->pc + 8;
319 return;
320 case 0x03: /* l.bnf */
321 if (regs->sr & SPR_SR_F)
322 regs->pc += 8;
323 else
324 regs->pc += displacement;
325 return;
326 case 0x04: /* l.bf */
327 if (regs->sr & SPR_SR_F)
328 regs->pc += displacement;
329 else
330 regs->pc += 8;
331 return;
332 case 0x11: /* l.jr */
333 regs->pc = regs->gpr[rb];
334 return;
335 case 0x12: /* l.jalr */
336 regs->pc = regs->gpr[rb];
337 regs->gpr[9] = regs->pc + 8;
338 return;
339 default:
340 break;
341 }
342 } else {
343 regs->pc += 4;
344 }
345 }
346
simulate_lwa(struct pt_regs * regs,unsigned long address,unsigned int insn)347 static inline void simulate_lwa(struct pt_regs *regs, unsigned long address,
348 unsigned int insn)
349 {
350 unsigned int ra, rd;
351 unsigned long value;
352 unsigned long orig_pc;
353 long imm;
354
355 const struct exception_table_entry *entry;
356
357 orig_pc = regs->pc;
358 adjust_pc(regs, address);
359
360 ra = (insn >> 16) & 0x1f;
361 rd = (insn >> 21) & 0x1f;
362 imm = (short)insn;
363 lwa_addr = (unsigned long __user *)(regs->gpr[ra] + imm);
364
365 if ((unsigned long)lwa_addr & 0x3) {
366 do_unaligned_access(regs, address);
367 return;
368 }
369
370 if (get_user(value, lwa_addr)) {
371 if (user_mode(regs)) {
372 force_sig(SIGSEGV);
373 return;
374 }
375
376 if ((entry = search_exception_tables(orig_pc))) {
377 regs->pc = entry->fixup;
378 return;
379 }
380
381 /* kernel access in kernel space, load it directly */
382 value = *((unsigned long *)lwa_addr);
383 }
384
385 lwa_flag = 1;
386 regs->gpr[rd] = value;
387 }
388
simulate_swa(struct pt_regs * regs,unsigned long address,unsigned int insn)389 static inline void simulate_swa(struct pt_regs *regs, unsigned long address,
390 unsigned int insn)
391 {
392 unsigned long __user *vaddr;
393 unsigned long orig_pc;
394 unsigned int ra, rb;
395 long imm;
396
397 const struct exception_table_entry *entry;
398
399 orig_pc = regs->pc;
400 adjust_pc(regs, address);
401
402 ra = (insn >> 16) & 0x1f;
403 rb = (insn >> 11) & 0x1f;
404 imm = (short)(((insn & 0x2200000) >> 10) | (insn & 0x7ff));
405 vaddr = (unsigned long __user *)(regs->gpr[ra] + imm);
406
407 if (!lwa_flag || vaddr != lwa_addr) {
408 regs->sr &= ~SPR_SR_F;
409 return;
410 }
411
412 if ((unsigned long)vaddr & 0x3) {
413 do_unaligned_access(regs, address);
414 return;
415 }
416
417 if (put_user(regs->gpr[rb], vaddr)) {
418 if (user_mode(regs)) {
419 force_sig(SIGSEGV);
420 return;
421 }
422
423 if ((entry = search_exception_tables(orig_pc))) {
424 regs->pc = entry->fixup;
425 return;
426 }
427
428 /* kernel access in kernel space, store it directly */
429 *((unsigned long *)vaddr) = regs->gpr[rb];
430 }
431
432 lwa_flag = 0;
433 regs->sr |= SPR_SR_F;
434 }
435
436 #define INSN_LWA 0x1b
437 #define INSN_SWA 0x33
438
do_illegal_instruction(struct pt_regs * regs,unsigned long address)439 asmlinkage void do_illegal_instruction(struct pt_regs *regs,
440 unsigned long address)
441 {
442 unsigned int op;
443 unsigned int insn = *((unsigned int *)address);
444
445 op = insn >> 26;
446
447 switch (op) {
448 case INSN_LWA:
449 simulate_lwa(regs, address, insn);
450 return;
451
452 case INSN_SWA:
453 simulate_swa(regs, address, insn);
454 return;
455
456 default:
457 break;
458 }
459
460 if (user_mode(regs)) {
461 /* Send a SIGILL */
462 force_sig_fault(SIGILL, ILL_ILLOPC, (void __user *)address);
463 } else { /* Kernel mode */
464 printk("KERNEL: Illegal instruction (SIGILL) 0x%.8lx\n",
465 address);
466 show_registers(regs);
467 die("Die:", regs, address);
468 }
469 }
470
