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