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\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 } 144 145 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 */ 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 } 237 238 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 } 244 245 asmlinkage void do_trap(struct pt_regs *regs, unsigned long address) 246 { 247 force_sig_fault(SIGTRAP, TRAP_BRKPT, (void __user *)regs->pc); 248 } 249 250 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 } 262 263 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 } 274 275 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 } 298 299 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 } 346 347 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 } 388 389 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 438 439 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