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/pgtable.h> 35 #include <asm/unwinder.h> 36 #include <asm/sections.h> 37 38 int kstack_depth_to_print = 0x180; 39 int lwa_flag; 40 unsigned long __user *lwa_addr; 41 42 void print_trace(void *data, unsigned long addr, int reliable) 43 { 44 pr_emerg("[<%p>] %s%pS\n", (void *) addr, reliable ? "" : "? ", 45 (void *) addr); 46 } 47 48 /* displays a short stack trace */ 49 void show_stack(struct task_struct *task, unsigned long *esp) 50 { 51 if (esp == NULL) 52 esp = (unsigned long *)&esp; 53 54 pr_emerg("Call trace:\n"); 55 unwind_stack(NULL, esp, print_trace); 56 } 57 58 void show_trace_task(struct task_struct *tsk) 59 { 60 /* 61 * TODO: SysRq-T trace dump... 62 */ 63 } 64 65 void show_registers(struct pt_regs *regs) 66 { 67 int i; 68 int in_kernel = 1; 69 unsigned long esp; 70 71 esp = (unsigned long)(regs->sp); 72 if (user_mode(regs)) 73 in_kernel = 0; 74 75 printk("CPU #: %d\n" 76 " PC: %08lx SR: %08lx SP: %08lx\n", 77 smp_processor_id(), regs->pc, regs->sr, regs->sp); 78 printk("GPR00: %08lx GPR01: %08lx GPR02: %08lx GPR03: %08lx\n", 79 0L, regs->gpr[1], regs->gpr[2], regs->gpr[3]); 80 printk("GPR04: %08lx GPR05: %08lx GPR06: %08lx GPR07: %08lx\n", 81 regs->gpr[4], regs->gpr[5], regs->gpr[6], regs->gpr[7]); 82 printk("GPR08: %08lx GPR09: %08lx GPR10: %08lx GPR11: %08lx\n", 83 regs->gpr[8], regs->gpr[9], regs->gpr[10], regs->gpr[11]); 84 printk("GPR12: %08lx GPR13: %08lx GPR14: %08lx GPR15: %08lx\n", 85 regs->gpr[12], regs->gpr[13], regs->gpr[14], regs->gpr[15]); 86 printk("GPR16: %08lx GPR17: %08lx GPR18: %08lx GPR19: %08lx\n", 87 regs->gpr[16], regs->gpr[17], regs->gpr[18], regs->gpr[19]); 88 printk("GPR20: %08lx GPR21: %08lx GPR22: %08lx GPR23: %08lx\n", 89 regs->gpr[20], regs->gpr[21], regs->gpr[22], regs->gpr[23]); 90 printk("GPR24: %08lx GPR25: %08lx GPR26: %08lx GPR27: %08lx\n", 91 regs->gpr[24], regs->gpr[25], regs->gpr[26], regs->gpr[27]); 92 printk("GPR28: %08lx GPR29: %08lx GPR30: %08lx GPR31: %08lx\n", 93 regs->gpr[28], regs->gpr[29], regs->gpr[30], regs->gpr[31]); 94 printk(" RES: %08lx oGPR11: %08lx\n", 95 regs->gpr[11], regs->orig_gpr11); 96 97 printk("Process %s (pid: %d, stackpage=%08lx)\n", 98 current->comm, current->pid, (unsigned long)current); 99 /* 100 * When in-kernel, we also print out the stack and code at the 101 * time of the fault.. 102 */ 103 if (in_kernel) { 104 105 printk("\nStack: "); 106 show_stack(NULL, (unsigned long *)esp); 107 108 printk("\nCode: "); 109 if (regs->pc < PAGE_OFFSET) 110 goto bad; 111 112 for (i = -24; i < 24; i++) { 113 unsigned char c; 114 if (__get_user(c, &((unsigned char *)regs->pc)[i])) { 115 bad: 116 printk(" Bad PC value."); 117 break; 118 } 119 120 if (i == 0) 121 printk("(%02x) ", c); 122 else 123 printk("%02x ", c); 124 } 125 } 126 printk("\n"); 127 } 128 129 void nommu_dump_state(struct pt_regs *regs, 130 unsigned long ea, unsigned long vector) 131 { 132 int i; 133 unsigned long addr, stack = regs->sp; 134 135 printk("\n\r[nommu_dump_state] :: ea %lx, vector %lx\n\r", ea, vector); 136 137 printk("CPU #: %d\n" 138 " PC: %08lx SR: %08lx SP: %08lx\n", 139 0, regs->pc, regs->sr, regs->sp); 140 printk("GPR00: %08lx GPR01: %08lx GPR02: %08lx GPR03: %08lx\n", 141 0L, regs->gpr[1], regs->gpr[2], regs->gpr[3]); 142 printk("GPR04: %08lx GPR05: %08lx GPR06: %08lx GPR07: %08lx\n", 143 regs->gpr[4], regs->gpr[5], regs->gpr[6], regs->gpr[7]); 144 printk("GPR08: %08lx GPR09: %08lx GPR10: %08lx GPR11: %08lx\n", 145 regs->gpr[8], regs->gpr[9], regs->gpr[10], regs->gpr[11]); 146 printk("GPR12: %08lx GPR13: %08lx GPR14: %08lx GPR15: %08lx\n", 147 regs->gpr[12], regs->gpr[13], regs->gpr[14], regs->gpr[15]); 148 printk("GPR16: %08lx GPR17: %08lx GPR18: %08lx GPR19: %08lx\n", 149 regs->gpr[16], regs->gpr[17], regs->gpr[18], regs->gpr[19]); 150 printk("GPR20: %08lx GPR21: %08lx GPR22: %08lx GPR23: %08lx\n", 151 regs->gpr[20], regs->gpr[21], regs->gpr[22], regs->gpr[23]); 152 printk("GPR24: %08lx GPR25: %08lx GPR26: %08lx GPR27: %08lx\n", 153 regs->gpr[24], regs->gpr[25], regs->gpr[26], regs->gpr[27]); 154 printk("GPR28: %08lx GPR29: %08lx GPR30: %08lx GPR31: %08lx\n", 155 regs->gpr[28], regs->gpr[29], regs->gpr[30], regs->gpr[31]); 156 printk(" RES: %08lx oGPR11: %08lx\n", 157 regs->gpr[11], regs->orig_gpr11); 158 159 printk("Process %s (pid: %d, stackpage=%08lx)\n", 160 ((struct task_struct *)(__pa(current)))->comm, 161 ((struct task_struct *)(__pa(current)))->pid, 162 (unsigned long)current); 163 164 printk("\nStack: "); 165 printk("Stack dump [0x%08lx]:\n", (unsigned long)stack); 166 for (i = 0; i < kstack_depth_to_print; i++) { 167 if (((long)stack & (THREAD_SIZE - 1)) == 0) 168 break; 169 stack++; 170 171 printk("%lx :: sp + %02d: 0x%08lx\n", stack, i * 4, 172 *((unsigned long *)(__pa(stack)))); 173 } 174 printk("\n"); 175 176 printk("Call Trace: "); 177 i = 1; 178 while (((long)stack & (THREAD_SIZE - 1)) != 0) { 179 addr = *((unsigned long *)__pa(stack)); 180 stack++; 181 182 if (kernel_text_address(addr)) { 183 if (i && ((i % 6) == 0)) 184 printk("\n "); 185 printk(" [<%08lx>]", addr); 186 i++; 187 } 188 } 189 printk("\n"); 190 191 printk("\nCode: "); 192 193 for (i = -24; i < 24; i++) { 194 unsigned char c; 195 c = ((unsigned char *)(__pa(regs->pc)))[i]; 196 197 if (i == 0) 198 printk("(%02x) ", c); 199 else 200 printk("%02x ", c); 201 } 202 printk("\n"); 203 } 204 205 /* This is normally the 'Oops' routine */ 206 void die(const char *str, struct pt_regs *regs, long err) 207 { 208 209 console_verbose(); 210 printk("\n%s#: %04lx\n", str, err & 0xffff); 211 show_registers(regs); 212 #ifdef CONFIG_JUMP_UPON_UNHANDLED_EXCEPTION 213 printk("\n\nUNHANDLED_EXCEPTION: entering infinite loop\n"); 214 215 /* shut down interrupts */ 216 local_irq_disable(); 217 218 __asm__ __volatile__("l.nop 1"); 219 do {} while (1); 220 #endif 221 do_exit(SIGSEGV); 222 } 223 224 /* This is normally the 'Oops' routine */ 225 void die_if_kernel(const char *str, struct pt_regs *regs, long err) 226 { 227 if (user_mode(regs)) 228 return; 229 230 die(str, regs, err); 231 } 232 233 void unhandled_exception(struct pt_regs *regs, int ea, int vector) 234 { 235 printk("Unable to handle exception at EA =0x%x, vector 0x%x", 236 ea, vector); 237 die("Oops", regs, 9); 238 } 239 240 void __init trap_init(void) 241 { 242 /* Nothing needs to be done */ 243 } 244 245 asmlinkage void do_trap(struct pt_regs *regs, unsigned long address) 246 { 247 force_sig_fault(SIGTRAP, TRAP_TRACE, (void __user *)address); 248 249 regs->pc += 4; 250 } 251 252 asmlinkage void do_unaligned_access(struct pt_regs *regs, unsigned long address) 253 { 254 if (user_mode(regs)) { 255 /* Send a SIGBUS */ 256 force_sig_fault(SIGBUS, BUS_ADRALN, (void __user *)address); 257 } else { 258 printk("KERNEL: Unaligned Access 0x%.8lx\n", address); 259 show_registers(regs); 260 die("Die:", regs, address); 261 } 262 263 } 264 265 asmlinkage void do_bus_fault(struct pt_regs *regs, unsigned long address) 266 { 267 if (user_mode(regs)) { 268 /* Send a SIGBUS */ 269 force_sig_fault(SIGBUS, BUS_ADRERR, (void __user *)address); 270 } else { /* Kernel mode */ 271 printk("KERNEL: Bus error (SIGBUS) 0x%.8lx\n", address); 272 show_registers(regs); 273 die("Die:", regs, address); 274 } 275 } 276 277 static inline int in_delay_slot(struct pt_regs *regs) 278 { 279 #ifdef CONFIG_OPENRISC_NO_SPR_SR_DSX 280 /* No delay slot flag, do the old way */ 281 unsigned int op, insn; 282 283 insn = *((unsigned int *)regs->pc); 284 op = insn >> 26; 285 switch (op) { 286 case 0x00: /* l.j */ 287 case 0x01: /* l.jal */ 288 case 0x03: /* l.bnf */ 289 case 0x04: /* l.bf */ 290 case 0x11: /* l.jr */ 291 case 0x12: /* l.jalr */ 292 return 1; 293 default: 294 return 0; 295 } 296 #else 297 return mfspr(SPR_SR) & SPR_SR_DSX; 298 #endif 299 } 300 301 static inline void adjust_pc(struct pt_regs *regs, unsigned long address) 302 { 303 int displacement; 304 unsigned int rb, op, jmp; 305 306 if (unlikely(in_delay_slot(regs))) { 307 /* In delay slot, instruction at pc is a branch, simulate it */ 308 jmp = *((unsigned int *)regs->pc); 309 310 displacement = sign_extend32(((jmp) & 0x3ffffff) << 2, 27); 311 rb = (jmp & 0x0000ffff) >> 11; 312 op = jmp >> 26; 313 314 switch (op) { 315 case 0x00: /* l.j */ 316 regs->pc += displacement; 317 return; 318 case 0x01: /* l.jal */ 319 regs->pc += displacement; 320 regs->gpr[9] = regs->pc + 8; 321 return; 322 case 0x03: /* l.bnf */ 323 if (regs->sr & SPR_SR_F) 324 regs->pc += 8; 325 else 326 regs->pc += displacement; 327 return; 328 case 0x04: /* l.bf */ 329 if (regs->sr & SPR_SR_F) 330 regs->pc += displacement; 331 else 332 regs->pc += 8; 333 return; 334 case 0x11: /* l.jr */ 335 regs->pc = regs->gpr[rb]; 336 return; 337 case 0x12: /* l.jalr */ 338 regs->pc = regs->gpr[rb]; 339 regs->gpr[9] = regs->pc + 8; 340 return; 341 default: 342 break; 343 } 344 } else { 345 regs->pc += 4; 346 } 347 } 348 349 static inline void simulate_lwa(struct pt_regs *regs, unsigned long address, 350 unsigned int insn) 351 { 352 unsigned int ra, rd; 353 unsigned long value; 354 unsigned long orig_pc; 355 long imm; 356 357 const struct exception_table_entry *entry; 358 359 orig_pc = regs->pc; 360 adjust_pc(regs, address); 361 362 ra = (insn >> 16) & 0x1f; 363 rd = (insn >> 21) & 0x1f; 364 imm = (short)insn; 365 lwa_addr = (unsigned long __user *)(regs->gpr[ra] + imm); 366 367 if ((unsigned long)lwa_addr & 0x3) { 368 do_unaligned_access(regs, address); 369 return; 370 } 371 372 if (get_user(value, lwa_addr)) { 373 if (user_mode(regs)) { 374 force_sig(SIGSEGV); 375 return; 376 } 377 378 if ((entry = search_exception_tables(orig_pc))) { 379 regs->pc = entry->fixup; 380 return; 381 } 382 383 /* kernel access in kernel space, load it directly */ 384 value = *((unsigned long *)lwa_addr); 385 } 386 387 lwa_flag = 1; 388 regs->gpr[rd] = value; 389 } 390 391 static inline void simulate_swa(struct pt_regs *regs, unsigned long address, 392 unsigned int insn) 393 { 394 unsigned long __user *vaddr; 395 unsigned long orig_pc; 396 unsigned int ra, rb; 397 long imm; 398 399 const struct exception_table_entry *entry; 400 401 orig_pc = regs->pc; 402 adjust_pc(regs, address); 403 404 ra = (insn >> 16) & 0x1f; 405 rb = (insn >> 11) & 0x1f; 406 imm = (short)(((insn & 0x2200000) >> 10) | (insn & 0x7ff)); 407 vaddr = (unsigned long __user *)(regs->gpr[ra] + imm); 408 409 if (!lwa_flag || vaddr != lwa_addr) { 410 regs->sr &= ~SPR_SR_F; 411 return; 412 } 413 414 if ((unsigned long)vaddr & 0x3) { 415 do_unaligned_access(regs, address); 416 return; 417 } 418 419 if (put_user(regs->gpr[rb], vaddr)) { 420 if (user_mode(regs)) { 421 force_sig(SIGSEGV); 422 return; 423 } 424 425 if ((entry = search_exception_tables(orig_pc))) { 426 regs->pc = entry->fixup; 427 return; 428 } 429 430 /* kernel access in kernel space, store it directly */ 431 *((unsigned long *)vaddr) = regs->gpr[rb]; 432 } 433 434 lwa_flag = 0; 435 regs->sr |= SPR_SR_F; 436 } 437 438 #define INSN_LWA 0x1b 439 #define INSN_SWA 0x33 440 441 asmlinkage void do_illegal_instruction(struct pt_regs *regs, 442 unsigned long address) 443 { 444 unsigned int op; 445 unsigned int insn = *((unsigned int *)address); 446 447 op = insn >> 26; 448 449 switch (op) { 450 case INSN_LWA: 451 simulate_lwa(regs, address, insn); 452 return; 453 454 case INSN_SWA: 455 simulate_swa(regs, address, insn); 456 return; 457 458 default: 459 break; 460 } 461 462 if (user_mode(regs)) { 463 /* Send a SIGILL */ 464 force_sig_fault(SIGILL, ILL_ILLOPC, (void __user *)address); 465 } else { /* Kernel mode */ 466 printk("KERNEL: Illegal instruction (SIGILL) 0x%.8lx\n", 467 address); 468 show_registers(regs); 469 die("Die:", regs, address); 470 } 471 } 472