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