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 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 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 */ 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 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 FPCSR: %08lx\n", 79 smp_processor_id(), regs->pc, regs->sr, regs->sp, 80 regs->fpcsr); 81 printk("GPR00: %08lx GPR01: %08lx GPR02: %08lx GPR03: %08lx\n", 82 0L, regs->gpr[1], regs->gpr[2], regs->gpr[3]); 83 printk("GPR04: %08lx GPR05: %08lx GPR06: %08lx GPR07: %08lx\n", 84 regs->gpr[4], regs->gpr[5], regs->gpr[6], regs->gpr[7]); 85 printk("GPR08: %08lx GPR09: %08lx GPR10: %08lx GPR11: %08lx\n", 86 regs->gpr[8], regs->gpr[9], regs->gpr[10], regs->gpr[11]); 87 printk("GPR12: %08lx GPR13: %08lx GPR14: %08lx GPR15: %08lx\n", 88 regs->gpr[12], regs->gpr[13], regs->gpr[14], regs->gpr[15]); 89 printk("GPR16: %08lx GPR17: %08lx GPR18: %08lx GPR19: %08lx\n", 90 regs->gpr[16], regs->gpr[17], regs->gpr[18], regs->gpr[19]); 91 printk("GPR20: %08lx GPR21: %08lx GPR22: %08lx GPR23: %08lx\n", 92 regs->gpr[20], regs->gpr[21], regs->gpr[22], regs->gpr[23]); 93 printk("GPR24: %08lx GPR25: %08lx GPR26: %08lx GPR27: %08lx\n", 94 regs->gpr[24], regs->gpr[25], regs->gpr[26], regs->gpr[27]); 95 printk("GPR28: %08lx GPR29: %08lx GPR30: %08lx GPR31: %08lx\n", 96 regs->gpr[28], regs->gpr[29], regs->gpr[30], regs->gpr[31]); 97 printk(" RES: %08lx oGPR11: %08lx\n", 98 regs->gpr[11], regs->orig_gpr11); 99 100 printk("Process %s (pid: %d, stackpage=%08lx)\n", 101 current->comm, current->pid, (unsigned long)current); 102 /* 103 * When in-kernel, we also print out the stack and code at the 104 * time of the fault.. 105 */ 106 if (in_kernel) { 107 108 printk("\nStack: "); 109 show_stack(NULL, (unsigned long *)esp, KERN_EMERG); 110 111 if (esp < PAGE_OFFSET) 112 goto bad_stack; 113 114 printk("\n"); 115 for (i = -8; i < 24; i += 1) { 116 unsigned long word; 117 118 if (__get_user(word, &((unsigned long *)esp)[i])) { 119 bad_stack: 120 printk(" Bad Stack value."); 121 break; 122 } 123 124 print_data(esp, word, i); 125 } 126 127 printk("\nCode: "); 128 if (regs->pc < PAGE_OFFSET) 129 goto bad; 130 131 for (i = -6; i < 6; i += 1) { 132 unsigned long word; 133 134 if (__get_user(word, &((unsigned long *)regs->pc)[i])) { 135 bad: 136 printk(" Bad PC value."); 137 break; 138 } 139 140 print_data(regs->pc, word, i); 141 } 142 } 143 printk("\n"); 144 } 145 146 void nommu_dump_state(struct pt_regs *regs, 147 unsigned long ea, unsigned long vector) 148 { 149 int i; 150 unsigned long addr, stack = regs->sp; 151 152 printk("\n\r[nommu_dump_state] :: ea %lx, vector %lx\n\r", ea, vector); 153 154 printk("CPU #: %d\n" 155 " PC: %08lx SR: %08lx SP: %08lx\n", 156 0, regs->pc, regs->sr, regs->sp); 157 printk("GPR00: %08lx GPR01: %08lx GPR02: %08lx GPR03: %08lx\n", 158 0L, regs->gpr[1], regs->gpr[2], regs->gpr[3]); 159 printk("GPR04: %08lx GPR05: %08lx GPR06: %08lx GPR07: %08lx\n", 160 regs->gpr[4], regs->gpr[5], regs->gpr[6], regs->gpr[7]); 161 printk("GPR08: %08lx GPR09: %08lx GPR10: %08lx GPR11: %08lx\n", 162 regs->gpr[8], regs->gpr[9], regs->gpr[10], regs->gpr[11]); 163 printk("GPR12: %08lx GPR13: %08lx GPR14: %08lx GPR15: %08lx\n", 164 regs->gpr[12], regs->gpr[13], regs->gpr[14], regs->gpr[15]); 165 printk("GPR16: %08lx GPR17: %08lx GPR18: %08lx GPR19: %08lx\n", 166 regs->gpr[16], regs->gpr[17], regs->gpr[18], regs->gpr[19]); 167 printk("GPR20: %08lx GPR21: %08lx GPR22: %08lx GPR23: %08lx\n", 168 regs->gpr[20], regs->gpr[21], regs->gpr[22], regs->gpr[23]); 169 printk("GPR24: %08lx GPR25: %08lx GPR26: %08lx GPR27: %08lx\n", 170 regs->gpr[24], regs->gpr[25], regs->gpr[26], regs->gpr[27]); 171 printk("GPR28: %08lx GPR29: %08lx GPR30: %08lx GPR31: %08lx\n", 172 regs->gpr[28], regs->gpr[29], regs->gpr[30], regs->gpr[31]); 173 printk(" RES: %08lx oGPR11: %08lx\n", 174 regs->gpr[11], regs->orig_gpr11); 175 176 printk("Process %s (pid: %d, stackpage=%08lx)\n", 177 ((struct task_struct *)(__pa(current)))->comm, 178 ((struct task_struct *)(__pa(current)))->pid, 179 (unsigned long)current); 180 181 printk("\nStack: "); 182 printk("Stack dump [0x%08lx]:\n", (unsigned long)stack); 183 for (i = 0; i < kstack_depth_to_print; i++) { 184 if (((long)stack & (THREAD_SIZE - 1)) == 0) 185 break; 186 stack++; 187 188 printk("%lx :: sp + %02d: 0x%08lx\n", stack, i * 4, 189 *((unsigned long *)(__pa(stack)))); 190 } 191 printk("\n"); 192 193 printk("Call Trace: "); 194 i = 1; 195 while (((long)stack & (THREAD_SIZE - 1)) != 0) { 196 addr = *((unsigned long *)__pa(stack)); 197 stack++; 198 199 if (kernel_text_address(addr)) { 200 if (i && ((i % 6) == 0)) 201 printk("\n "); 202 printk(" [<%08lx>]", addr); 203 i++; 204 } 205 } 206 printk("\n"); 207 208 printk("\nCode: "); 209 210 for (i = -24; i < 24; i++) { 211 unsigned long word; 212 213 word = ((unsigned long *)(__pa(regs->pc)))[i]; 214 215 print_data(regs->pc, word, i); 216 } 217 printk("\n"); 218 } 219 220 /* This is normally the 'Oops' routine */ 221 void __noreturn die(const char *str, struct pt_regs *regs, long err) 222 { 223 224 console_verbose(); 225 printk("\n%s#: %04lx\n", str, err & 0xffff); 226 show_registers(regs); 227 #ifdef CONFIG_JUMP_UPON_UNHANDLED_EXCEPTION 228 printk("\n\nUNHANDLED_EXCEPTION: entering infinite loop\n"); 229 230 /* shut down interrupts */ 231 local_irq_disable(); 232 233 __asm__ __volatile__("l.nop 1"); 234 do {} while (1); 235 #endif 236 make_task_dead(SIGSEGV); 237 } 238 239 asmlinkage 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 asmlinkage void do_fpe_trap(struct pt_regs *regs, unsigned long address) 247 { 248 int code = FPE_FLTUNK; 249 unsigned long fpcsr = regs->fpcsr; 250 251 if (fpcsr & SPR_FPCSR_IVF) 252 code = FPE_FLTINV; 253 else if (fpcsr & SPR_FPCSR_OVF) 254 code = FPE_FLTOVF; 255 else if (fpcsr & SPR_FPCSR_UNF) 256 code = FPE_FLTUND; 257 else if (fpcsr & SPR_FPCSR_DZF) 258 code = FPE_FLTDIV; 259 else if (fpcsr & SPR_FPCSR_IXF) 260 code = FPE_FLTRES; 261 262 /* Clear all flags */ 263 regs->fpcsr &= ~SPR_FPCSR_ALLF; 264 265 force_sig_fault(SIGFPE, code, (void __user *)regs->pc); 266 } 267 268 asmlinkage void do_trap(struct pt_regs *regs, unsigned long address) 269 { 270 force_sig_fault(SIGTRAP, TRAP_BRKPT, (void __user *)regs->pc); 271 } 272 273 asmlinkage void do_unaligned_access(struct pt_regs *regs, unsigned long address) 274 { 275 if (user_mode(regs)) { 276 /* Send a SIGBUS */ 277 force_sig_fault(SIGBUS, BUS_ADRALN, (void __user *)address); 278 } else { 279 printk("KERNEL: Unaligned Access 0x%.8lx\n", address); 280 show_registers(regs); 281 die("Die:", regs, address); 282 } 283 284 } 285 286 asmlinkage void do_bus_fault(struct pt_regs *regs, unsigned long address) 287 { 288 if (user_mode(regs)) { 289 /* Send a SIGBUS */ 290 force_sig_fault(SIGBUS, BUS_ADRERR, (void __user *)address); 291 } else { /* Kernel mode */ 292 printk("KERNEL: Bus error (SIGBUS) 0x%.8lx\n", address); 293 show_registers(regs); 294 die("Die:", regs, address); 295 } 296 } 297 298 static inline int in_delay_slot(struct pt_regs *regs) 299 { 300 #ifdef CONFIG_OPENRISC_NO_SPR_SR_DSX 301 /* No delay slot flag, do the old way */ 302 unsigned int op, insn; 303 304 insn = *((unsigned int *)regs->pc); 305 op = insn >> 26; 306 switch (op) { 307 case 0x00: /* l.j */ 308 case 0x01: /* l.jal */ 309 case 0x03: /* l.bnf */ 310 case 0x04: /* l.bf */ 311 case 0x11: /* l.jr */ 312 case 0x12: /* l.jalr */ 313 return 1; 314 default: 315 return 0; 316 } 317 #else 318 return mfspr(SPR_SR) & SPR_SR_DSX; 319 #endif 320 } 321 322 static inline void adjust_pc(struct pt_regs *regs, unsigned long address) 323 { 324 int displacement; 325 unsigned int rb, op, jmp; 326 327 if (unlikely(in_delay_slot(regs))) { 328 /* In delay slot, instruction at pc is a branch, simulate it */ 329 jmp = *((unsigned int *)regs->pc); 330 331 displacement = sign_extend32(((jmp) & 0x3ffffff) << 2, 27); 332 rb = (jmp & 0x0000ffff) >> 11; 333 op = jmp >> 26; 334 335 switch (op) { 336 case 0x00: /* l.j */ 337 regs->pc += displacement; 338 return; 339 case 0x01: /* l.jal */ 340 regs->pc += displacement; 341 regs->gpr[9] = regs->pc + 8; 342 return; 343 case 0x03: /* l.bnf */ 344 if (regs->sr & SPR_SR_F) 345 regs->pc += 8; 346 else 347 regs->pc += displacement; 348 return; 349 case 0x04: /* l.bf */ 350 if (regs->sr & SPR_SR_F) 351 regs->pc += displacement; 352 else 353 regs->pc += 8; 354 return; 355 case 0x11: /* l.jr */ 356 regs->pc = regs->gpr[rb]; 357 return; 358 case 0x12: /* l.jalr */ 359 regs->pc = regs->gpr[rb]; 360 regs->gpr[9] = regs->pc + 8; 361 return; 362 default: 363 break; 364 } 365 } else { 366 regs->pc += 4; 367 } 368 } 369 370 static inline void simulate_lwa(struct pt_regs *regs, unsigned long address, 371 unsigned int insn) 372 { 373 unsigned int ra, rd; 374 unsigned long value; 375 unsigned long orig_pc; 376 long imm; 377 378 const struct exception_table_entry *entry; 379 380 orig_pc = regs->pc; 381 adjust_pc(regs, address); 382 383 ra = (insn >> 16) & 0x1f; 384 rd = (insn >> 21) & 0x1f; 385 imm = (short)insn; 386 lwa_addr = (unsigned long __user *)(regs->gpr[ra] + imm); 387 388 if ((unsigned long)lwa_addr & 0x3) { 389 do_unaligned_access(regs, address); 390 return; 391 } 392 393 if (get_user(value, lwa_addr)) { 394 if (user_mode(regs)) { 395 force_sig(SIGSEGV); 396 return; 397 } 398 399 if ((entry = search_exception_tables(orig_pc))) { 400 regs->pc = entry->fixup; 401 return; 402 } 403 404 /* kernel access in kernel space, load it directly */ 405 value = *((unsigned long *)lwa_addr); 406 } 407 408 lwa_flag = 1; 409 regs->gpr[rd] = value; 410 } 411 412 static inline void simulate_swa(struct pt_regs *regs, unsigned long address, 413 unsigned int insn) 414 { 415 unsigned long __user *vaddr; 416 unsigned long orig_pc; 417 unsigned int ra, rb; 418 long imm; 419 420 const struct exception_table_entry *entry; 421 422 orig_pc = regs->pc; 423 adjust_pc(regs, address); 424 425 ra = (insn >> 16) & 0x1f; 426 rb = (insn >> 11) & 0x1f; 427 imm = (short)(((insn & 0x2200000) >> 10) | (insn & 0x7ff)); 428 vaddr = (unsigned long __user *)(regs->gpr[ra] + imm); 429 430 if (!lwa_flag || vaddr != lwa_addr) { 431 regs->sr &= ~SPR_SR_F; 432 return; 433 } 434 435 if ((unsigned long)vaddr & 0x3) { 436 do_unaligned_access(regs, address); 437 return; 438 } 439 440 if (put_user(regs->gpr[rb], vaddr)) { 441 if (user_mode(regs)) { 442 force_sig(SIGSEGV); 443 return; 444 } 445 446 if ((entry = search_exception_tables(orig_pc))) { 447 regs->pc = entry->fixup; 448 return; 449 } 450 451 /* kernel access in kernel space, store it directly */ 452 *((unsigned long *)vaddr) = regs->gpr[rb]; 453 } 454 455 lwa_flag = 0; 456 regs->sr |= SPR_SR_F; 457 } 458 459 #define INSN_LWA 0x1b 460 #define INSN_SWA 0x33 461 462 asmlinkage void do_illegal_instruction(struct pt_regs *regs, 463 unsigned long address) 464 { 465 unsigned int op; 466 unsigned int insn = *((unsigned int *)address); 467 468 op = insn >> 26; 469 470 switch (op) { 471 case INSN_LWA: 472 simulate_lwa(regs, address, insn); 473 return; 474 475 case INSN_SWA: 476 simulate_swa(regs, address, insn); 477 return; 478 479 default: 480 break; 481 } 482 483 if (user_mode(regs)) { 484 /* Send a SIGILL */ 485 force_sig_fault(SIGILL, ILL_ILLOPC, (void __user *)address); 486 } else { /* Kernel mode */ 487 printk("KERNEL: Illegal instruction (SIGILL) 0x%.8lx\n", 488 address); 489 show_registers(regs); 490 die("Die:", regs, address); 491 } 492 } 493