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 44 int kstack_depth_to_print = 0x180; 45 int lwa_flag; 46 unsigned long __user *lwa_addr; 47 48 void 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 */ 55 void 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 64 void show_trace_task(struct task_struct *tsk) 65 { 66 /* 67 * TODO: SysRq-T trace dump... 68 */ 69 } 70 71 void 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])) { 121 bad: 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 } 134 135 void 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 */ 212 void 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 */ 231 void 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 } 238 239 void 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 } 245 246 void __init trap_init(void) 247 { 248 /* Nothing needs to be done */ 249 } 250 251 asmlinkage void do_trap(struct pt_regs *regs, unsigned long address) 252 { 253 siginfo_t info; 254 clear_siginfo(&info); 255 info.si_signo = SIGTRAP; 256 info.si_code = TRAP_TRACE; 257 info.si_addr = (void *)address; 258 force_sig_info(SIGTRAP, &info, current); 259 260 regs->pc += 4; 261 } 262 263 asmlinkage void do_unaligned_access(struct pt_regs *regs, unsigned long address) 264 { 265 siginfo_t info; 266 267 if (user_mode(regs)) { 268 /* Send a SIGBUS */ 269 clear_siginfo(&info); 270 info.si_signo = SIGBUS; 271 info.si_errno = 0; 272 info.si_code = BUS_ADRALN; 273 info.si_addr = (void __user *)address; 274 force_sig_info(SIGBUS, &info, current); 275 } else { 276 printk("KERNEL: Unaligned Access 0x%.8lx\n", address); 277 show_registers(regs); 278 die("Die:", regs, address); 279 } 280 281 } 282 283 asmlinkage void do_bus_fault(struct pt_regs *regs, unsigned long address) 284 { 285 siginfo_t info; 286 287 if (user_mode(regs)) { 288 /* Send a SIGBUS */ 289 clear_siginfo(&info); 290 info.si_signo = SIGBUS; 291 info.si_errno = 0; 292 info.si_code = BUS_ADRERR; 293 info.si_addr = (void *)address; 294 force_sig_info(SIGBUS, &info, current); 295 } else { /* Kernel mode */ 296 printk("KERNEL: Bus error (SIGBUS) 0x%.8lx\n", address); 297 show_registers(regs); 298 die("Die:", regs, address); 299 } 300 } 301 302 static inline int in_delay_slot(struct pt_regs *regs) 303 { 304 #ifdef CONFIG_OPENRISC_NO_SPR_SR_DSX 305 /* No delay slot flag, do the old way */ 306 unsigned int op, insn; 307 308 insn = *((unsigned int *)regs->pc); 309 op = insn >> 26; 310 switch (op) { 311 case 0x00: /* l.j */ 312 case 0x01: /* l.jal */ 313 case 0x03: /* l.bnf */ 314 case 0x04: /* l.bf */ 315 case 0x11: /* l.jr */ 316 case 0x12: /* l.jalr */ 317 return 1; 318 default: 319 return 0; 320 } 321 #else 322 return regs->sr & SPR_SR_DSX; 323 #endif 324 } 325 326 static inline void adjust_pc(struct pt_regs *regs, unsigned long address) 327 { 328 int displacement; 329 unsigned int rb, op, jmp; 330 331 if (unlikely(in_delay_slot(regs))) { 332 /* In delay slot, instruction at pc is a branch, simulate it */ 333 jmp = *((unsigned int *)regs->pc); 334 335 displacement = sign_extend32(((jmp) & 0x3ffffff) << 2, 27); 336 rb = (jmp & 0x0000ffff) >> 11; 337 op = jmp >> 26; 338 339 switch (op) { 340 case 0x00: /* l.j */ 341 regs->pc += displacement; 342 return; 343 case 0x01: /* l.jal */ 344 regs->pc += displacement; 345 regs->gpr[9] = regs->pc + 8; 346 return; 347 case 0x03: /* l.bnf */ 348 if (regs->sr & SPR_SR_F) 349 regs->pc += 8; 350 else 351 regs->pc += displacement; 352 return; 353 case 0x04: /* l.bf */ 354 if (regs->sr & SPR_SR_F) 355 regs->pc += displacement; 356 else 357 regs->pc += 8; 358 return; 359 case 0x11: /* l.jr */ 360 regs->pc = regs->gpr[rb]; 361 return; 362 case 0x12: /* l.jalr */ 363 regs->pc = regs->gpr[rb]; 364 regs->gpr[9] = regs->pc + 8; 365 return; 366 default: 367 break; 368 } 369 } else { 370 regs->pc += 4; 371 } 372 } 373 374 static inline void simulate_lwa(struct pt_regs *regs, unsigned long address, 375 unsigned int insn) 376 { 377 unsigned int ra, rd; 378 unsigned long value; 379 unsigned long orig_pc; 380 long imm; 381 382 const struct exception_table_entry *entry; 383 384 orig_pc = regs->pc; 385 adjust_pc(regs, address); 386 387 ra = (insn >> 16) & 0x1f; 388 rd = (insn >> 21) & 0x1f; 389 imm = (short)insn; 390 lwa_addr = (unsigned long __user *)(regs->gpr[ra] + imm); 391 392 if ((unsigned long)lwa_addr & 0x3) { 393 do_unaligned_access(regs, address); 394 return; 395 } 396 397 if (get_user(value, lwa_addr)) { 398 if (user_mode(regs)) { 399 force_sig(SIGSEGV, current); 400 return; 401 } 402 403 if ((entry = search_exception_tables(orig_pc))) { 404 regs->pc = entry->fixup; 405 return; 406 } 407 408 /* kernel access in kernel space, load it directly */ 409 value = *((unsigned long *)lwa_addr); 410 } 411 412 lwa_flag = 1; 413 regs->gpr[rd] = value; 414 } 415 416 static inline void simulate_swa(struct pt_regs *regs, unsigned long address, 417 unsigned int insn) 418 { 419 unsigned long __user *vaddr; 420 unsigned long orig_pc; 421 unsigned int ra, rb; 422 long imm; 423 424 const struct exception_table_entry *entry; 425 426 orig_pc = regs->pc; 427 adjust_pc(regs, address); 428 429 ra = (insn >> 16) & 0x1f; 430 rb = (insn >> 11) & 0x1f; 431 imm = (short)(((insn & 0x2200000) >> 10) | (insn & 0x7ff)); 432 vaddr = (unsigned long __user *)(regs->gpr[ra] + imm); 433 434 if (!lwa_flag || vaddr != lwa_addr) { 435 regs->sr &= ~SPR_SR_F; 436 return; 437 } 438 439 if ((unsigned long)vaddr & 0x3) { 440 do_unaligned_access(regs, address); 441 return; 442 } 443 444 if (put_user(regs->gpr[rb], vaddr)) { 445 if (user_mode(regs)) { 446 force_sig(SIGSEGV, current); 447 return; 448 } 449 450 if ((entry = search_exception_tables(orig_pc))) { 451 regs->pc = entry->fixup; 452 return; 453 } 454 455 /* kernel access in kernel space, store it directly */ 456 *((unsigned long *)vaddr) = regs->gpr[rb]; 457 } 458 459 lwa_flag = 0; 460 regs->sr |= SPR_SR_F; 461 } 462 463 #define INSN_LWA 0x1b 464 #define INSN_SWA 0x33 465 466 asmlinkage void do_illegal_instruction(struct pt_regs *regs, 467 unsigned long address) 468 { 469 siginfo_t info; 470 unsigned int op; 471 unsigned int insn = *((unsigned int *)address); 472 473 op = insn >> 26; 474 475 switch (op) { 476 case INSN_LWA: 477 simulate_lwa(regs, address, insn); 478 return; 479 480 case INSN_SWA: 481 simulate_swa(regs, address, insn); 482 return; 483 484 default: 485 break; 486 } 487 488 if (user_mode(regs)) { 489 /* Send a SIGILL */ 490 clear_siginfo(&info); 491 info.si_signo = SIGILL; 492 info.si_errno = 0; 493 info.si_code = ILL_ILLOPC; 494 info.si_addr = (void *)address; 495 force_sig_info(SIGBUS, &info, current); 496 } else { /* Kernel mode */ 497 printk("KERNEL: Illegal instruction (SIGILL) 0x%.8lx\n", 498 address); 499 show_registers(regs); 500 die("Die:", regs, address); 501 } 502 } 503