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