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 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 */ 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 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 } 122 123 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 */ 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 do_exit(SIGSEGV); 216 } 217 218 /* This is normally the 'Oops' routine */ 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 } 226 227 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 } 233 234 void __init trap_init(void) 235 { 236 /* Nothing needs to be done */ 237 } 238 239 asmlinkage void do_trap(struct pt_regs *regs, unsigned long address) 240 { 241 force_sig_fault(SIGTRAP, TRAP_BRKPT, (void __user *)regs->pc); 242 } 243 244 asmlinkage void do_unaligned_access(struct pt_regs *regs, unsigned long address) 245 { 246 if (user_mode(regs)) { 247 /* Send a SIGBUS */ 248 force_sig_fault(SIGBUS, BUS_ADRALN, (void __user *)address); 249 } else { 250 printk("KERNEL: Unaligned Access 0x%.8lx\n", address); 251 show_registers(regs); 252 die("Die:", regs, address); 253 } 254 255 } 256 257 asmlinkage void do_bus_fault(struct pt_regs *regs, unsigned long address) 258 { 259 if (user_mode(regs)) { 260 /* Send a SIGBUS */ 261 force_sig_fault(SIGBUS, BUS_ADRERR, (void __user *)address); 262 } else { /* Kernel mode */ 263 printk("KERNEL: Bus error (SIGBUS) 0x%.8lx\n", address); 264 show_registers(regs); 265 die("Die:", regs, address); 266 } 267 } 268 269 static inline int in_delay_slot(struct pt_regs *regs) 270 { 271 #ifdef CONFIG_OPENRISC_NO_SPR_SR_DSX 272 /* No delay slot flag, do the old way */ 273 unsigned int op, insn; 274 275 insn = *((unsigned int *)regs->pc); 276 op = insn >> 26; 277 switch (op) { 278 case 0x00: /* l.j */ 279 case 0x01: /* l.jal */ 280 case 0x03: /* l.bnf */ 281 case 0x04: /* l.bf */ 282 case 0x11: /* l.jr */ 283 case 0x12: /* l.jalr */ 284 return 1; 285 default: 286 return 0; 287 } 288 #else 289 return mfspr(SPR_SR) & SPR_SR_DSX; 290 #endif 291 } 292 293 static inline void adjust_pc(struct pt_regs *regs, unsigned long address) 294 { 295 int displacement; 296 unsigned int rb, op, jmp; 297 298 if (unlikely(in_delay_slot(regs))) { 299 /* In delay slot, instruction at pc is a branch, simulate it */ 300 jmp = *((unsigned int *)regs->pc); 301 302 displacement = sign_extend32(((jmp) & 0x3ffffff) << 2, 27); 303 rb = (jmp & 0x0000ffff) >> 11; 304 op = jmp >> 26; 305 306 switch (op) { 307 case 0x00: /* l.j */ 308 regs->pc += displacement; 309 return; 310 case 0x01: /* l.jal */ 311 regs->pc += displacement; 312 regs->gpr[9] = regs->pc + 8; 313 return; 314 case 0x03: /* l.bnf */ 315 if (regs->sr & SPR_SR_F) 316 regs->pc += 8; 317 else 318 regs->pc += displacement; 319 return; 320 case 0x04: /* l.bf */ 321 if (regs->sr & SPR_SR_F) 322 regs->pc += displacement; 323 else 324 regs->pc += 8; 325 return; 326 case 0x11: /* l.jr */ 327 regs->pc = regs->gpr[rb]; 328 return; 329 case 0x12: /* l.jalr */ 330 regs->pc = regs->gpr[rb]; 331 regs->gpr[9] = regs->pc + 8; 332 return; 333 default: 334 break; 335 } 336 } else { 337 regs->pc += 4; 338 } 339 } 340 341 static inline void simulate_lwa(struct pt_regs *regs, unsigned long address, 342 unsigned int insn) 343 { 344 unsigned int ra, rd; 345 unsigned long value; 346 unsigned long orig_pc; 347 long imm; 348 349 const struct exception_table_entry *entry; 350 351 orig_pc = regs->pc; 352 adjust_pc(regs, address); 353 354 ra = (insn >> 16) & 0x1f; 355 rd = (insn >> 21) & 0x1f; 356 imm = (short)insn; 357 lwa_addr = (unsigned long __user *)(regs->gpr[ra] + imm); 358 359 if ((unsigned long)lwa_addr & 0x3) { 360 do_unaligned_access(regs, address); 361 return; 362 } 363 364 if (get_user(value, lwa_addr)) { 365 if (user_mode(regs)) { 366 force_sig(SIGSEGV); 367 return; 368 } 369 370 if ((entry = search_exception_tables(orig_pc))) { 371 regs->pc = entry->fixup; 372 return; 373 } 374 375 /* kernel access in kernel space, load it directly */ 376 value = *((unsigned long *)lwa_addr); 377 } 378 379 lwa_flag = 1; 380 regs->gpr[rd] = value; 381 } 382 383 static inline void simulate_swa(struct pt_regs *regs, unsigned long address, 384 unsigned int insn) 385 { 386 unsigned long __user *vaddr; 387 unsigned long orig_pc; 388 unsigned int ra, rb; 389 long imm; 390 391 const struct exception_table_entry *entry; 392 393 orig_pc = regs->pc; 394 adjust_pc(regs, address); 395 396 ra = (insn >> 16) & 0x1f; 397 rb = (insn >> 11) & 0x1f; 398 imm = (short)(((insn & 0x2200000) >> 10) | (insn & 0x7ff)); 399 vaddr = (unsigned long __user *)(regs->gpr[ra] + imm); 400 401 if (!lwa_flag || vaddr != lwa_addr) { 402 regs->sr &= ~SPR_SR_F; 403 return; 404 } 405 406 if ((unsigned long)vaddr & 0x3) { 407 do_unaligned_access(regs, address); 408 return; 409 } 410 411 if (put_user(regs->gpr[rb], vaddr)) { 412 if (user_mode(regs)) { 413 force_sig(SIGSEGV); 414 return; 415 } 416 417 if ((entry = search_exception_tables(orig_pc))) { 418 regs->pc = entry->fixup; 419 return; 420 } 421 422 /* kernel access in kernel space, store it directly */ 423 *((unsigned long *)vaddr) = regs->gpr[rb]; 424 } 425 426 lwa_flag = 0; 427 regs->sr |= SPR_SR_F; 428 } 429 430 #define INSN_LWA 0x1b 431 #define INSN_SWA 0x33 432 433 asmlinkage void do_illegal_instruction(struct pt_regs *regs, 434 unsigned long address) 435 { 436 unsigned int op; 437 unsigned int insn = *((unsigned int *)address); 438 439 op = insn >> 26; 440 441 switch (op) { 442 case INSN_LWA: 443 simulate_lwa(regs, address, insn); 444 return; 445 446 case INSN_SWA: 447 simulate_swa(regs, address, insn); 448 return; 449 450 default: 451 break; 452 } 453 454 if (user_mode(regs)) { 455 /* Send a SIGILL */ 456 force_sig_fault(SIGILL, ILL_ILLOPC, (void __user *)address); 457 } else { /* Kernel mode */ 458 printk("KERNEL: Illegal instruction (SIGILL) 0x%.8lx\n", 459 address); 460 show_registers(regs); 461 die("Die:", regs, address); 462 } 463 } 464