1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * Author: Huacai Chen <chenhuacai@loongson.cn> 4 * Copyright (C) 2020-2022 Loongson Technology Corporation Limited 5 */ 6 #include <linux/bitfield.h> 7 #include <linux/bitops.h> 8 #include <linux/bug.h> 9 #include <linux/compiler.h> 10 #include <linux/context_tracking.h> 11 #include <linux/entry-common.h> 12 #include <linux/init.h> 13 #include <linux/kernel.h> 14 #include <linux/kexec.h> 15 #include <linux/module.h> 16 #include <linux/extable.h> 17 #include <linux/mm.h> 18 #include <linux/sched/mm.h> 19 #include <linux/sched/debug.h> 20 #include <linux/smp.h> 21 #include <linux/spinlock.h> 22 #include <linux/kallsyms.h> 23 #include <linux/memblock.h> 24 #include <linux/interrupt.h> 25 #include <linux/ptrace.h> 26 #include <linux/kgdb.h> 27 #include <linux/kdebug.h> 28 #include <linux/notifier.h> 29 #include <linux/irq.h> 30 #include <linux/perf_event.h> 31 32 #include <asm/addrspace.h> 33 #include <asm/bootinfo.h> 34 #include <asm/branch.h> 35 #include <asm/break.h> 36 #include <asm/cpu.h> 37 #include <asm/exception.h> 38 #include <asm/fpu.h> 39 #include <asm/lbt.h> 40 #include <asm/inst.h> 41 #include <asm/kgdb.h> 42 #include <asm/loongarch.h> 43 #include <asm/mmu_context.h> 44 #include <asm/pgtable.h> 45 #include <asm/ptrace.h> 46 #include <asm/sections.h> 47 #include <asm/siginfo.h> 48 #include <asm/stacktrace.h> 49 #include <asm/tlb.h> 50 #include <asm/types.h> 51 #include <asm/unwind.h> 52 #include <asm/uprobes.h> 53 54 #include "access-helper.h" 55 56 static void show_backtrace(struct task_struct *task, const struct pt_regs *regs, 57 const char *loglvl, bool user) 58 { 59 unsigned long addr; 60 struct unwind_state state; 61 struct pt_regs *pregs = (struct pt_regs *)regs; 62 63 if (!task) 64 task = current; 65 66 printk("%sCall Trace:", loglvl); 67 for (unwind_start(&state, task, pregs); 68 !unwind_done(&state); unwind_next_frame(&state)) { 69 addr = unwind_get_return_address(&state); 70 print_ip_sym(loglvl, addr); 71 } 72 printk("%s\n", loglvl); 73 } 74 75 static void show_stacktrace(struct task_struct *task, 76 const struct pt_regs *regs, const char *loglvl, bool user) 77 { 78 int i; 79 const int field = 2 * sizeof(unsigned long); 80 unsigned long stackdata; 81 unsigned long *sp = (unsigned long *)regs->regs[3]; 82 83 printk("%sStack :", loglvl); 84 i = 0; 85 while ((unsigned long) sp & (PAGE_SIZE - 1)) { 86 if (i && ((i % (64 / field)) == 0)) { 87 pr_cont("\n"); 88 printk("%s ", loglvl); 89 } 90 if (i > 39) { 91 pr_cont(" ..."); 92 break; 93 } 94 95 if (__get_addr(&stackdata, sp++, user)) { 96 pr_cont(" (Bad stack address)"); 97 break; 98 } 99 100 pr_cont(" %0*lx", field, stackdata); 101 i++; 102 } 103 pr_cont("\n"); 104 show_backtrace(task, regs, loglvl, user); 105 } 106 107 void show_stack(struct task_struct *task, unsigned long *sp, const char *loglvl) 108 { 109 struct pt_regs regs; 110 111 regs.csr_crmd = 0; 112 if (sp) { 113 regs.csr_era = 0; 114 regs.regs[1] = 0; 115 regs.regs[3] = (unsigned long)sp; 116 } else { 117 if (!task || task == current) 118 prepare_frametrace(®s); 119 else { 120 regs.csr_era = task->thread.reg01; 121 regs.regs[1] = 0; 122 regs.regs[3] = task->thread.reg03; 123 regs.regs[22] = task->thread.reg22; 124 } 125 } 126 127 show_stacktrace(task, ®s, loglvl, false); 128 } 129 130 static void show_code(unsigned int *pc, bool user) 131 { 132 long i; 133 unsigned int insn; 134 135 printk("Code:"); 136 137 for(i = -3 ; i < 6 ; i++) { 138 if (__get_inst(&insn, pc + i, user)) { 139 pr_cont(" (Bad address in era)\n"); 140 break; 141 } 142 pr_cont("%c%08x%c", (i?' ':'<'), insn, (i?' ':'>')); 143 } 144 pr_cont("\n"); 145 } 146 147 static void print_bool_fragment(const char *key, unsigned long val, bool first) 148 { 149 /* e.g. "+PG", "-DA" */ 150 pr_cont("%s%c%s", first ? "" : " ", val ? '+' : '-', key); 151 } 152 153 static void print_plv_fragment(const char *key, int val) 154 { 155 /* e.g. "PLV0", "PPLV3" */ 156 pr_cont("%s%d", key, val); 157 } 158 159 static void print_memory_type_fragment(const char *key, unsigned long val) 160 { 161 const char *humanized_type; 162 163 switch (val) { 164 case 0: 165 humanized_type = "SUC"; 166 break; 167 case 1: 168 humanized_type = "CC"; 169 break; 170 case 2: 171 humanized_type = "WUC"; 172 break; 173 default: 174 pr_cont(" %s=Reserved(%lu)", key, val); 175 return; 176 } 177 178 /* e.g. " DATM=WUC" */ 179 pr_cont(" %s=%s", key, humanized_type); 180 } 181 182 static void print_intr_fragment(const char *key, unsigned long val) 183 { 184 /* e.g. "LIE=0-1,3,5-7" */ 185 pr_cont("%s=%*pbl", key, EXCCODE_INT_NUM, &val); 186 } 187 188 static void print_crmd(unsigned long x) 189 { 190 printk(" CRMD: %08lx (", x); 191 print_plv_fragment("PLV", (int) FIELD_GET(CSR_CRMD_PLV, x)); 192 print_bool_fragment("IE", FIELD_GET(CSR_CRMD_IE, x), false); 193 print_bool_fragment("DA", FIELD_GET(CSR_CRMD_DA, x), false); 194 print_bool_fragment("PG", FIELD_GET(CSR_CRMD_PG, x), false); 195 print_memory_type_fragment("DACF", FIELD_GET(CSR_CRMD_DACF, x)); 196 print_memory_type_fragment("DACM", FIELD_GET(CSR_CRMD_DACM, x)); 197 print_bool_fragment("WE", FIELD_GET(CSR_CRMD_WE, x), false); 198 pr_cont(")\n"); 199 } 200 201 static void print_prmd(unsigned long x) 202 { 203 printk(" PRMD: %08lx (", x); 204 print_plv_fragment("PPLV", (int) FIELD_GET(CSR_PRMD_PPLV, x)); 205 print_bool_fragment("PIE", FIELD_GET(CSR_PRMD_PIE, x), false); 206 print_bool_fragment("PWE", FIELD_GET(CSR_PRMD_PWE, x), false); 207 pr_cont(")\n"); 208 } 209 210 static void print_euen(unsigned long x) 211 { 212 printk(" EUEN: %08lx (", x); 213 print_bool_fragment("FPE", FIELD_GET(CSR_EUEN_FPEN, x), true); 214 print_bool_fragment("SXE", FIELD_GET(CSR_EUEN_LSXEN, x), false); 215 print_bool_fragment("ASXE", FIELD_GET(CSR_EUEN_LASXEN, x), false); 216 print_bool_fragment("BTE", FIELD_GET(CSR_EUEN_LBTEN, x), false); 217 pr_cont(")\n"); 218 } 219 220 static void print_ecfg(unsigned long x) 221 { 222 printk(" ECFG: %08lx (", x); 223 print_intr_fragment("LIE", FIELD_GET(CSR_ECFG_IM, x)); 224 pr_cont(" VS=%d)\n", (int) FIELD_GET(CSR_ECFG_VS, x)); 225 } 226 227 static const char *humanize_exc_name(unsigned int ecode, unsigned int esubcode) 228 { 229 /* 230 * LoongArch users and developers are probably more familiar with 231 * those names found in the ISA manual, so we are going to print out 232 * the latter. This will require some mapping. 233 */ 234 switch (ecode) { 235 case EXCCODE_RSV: return "INT"; 236 case EXCCODE_TLBL: return "PIL"; 237 case EXCCODE_TLBS: return "PIS"; 238 case EXCCODE_TLBI: return "PIF"; 239 case EXCCODE_TLBM: return "PME"; 240 case EXCCODE_TLBNR: return "PNR"; 241 case EXCCODE_TLBNX: return "PNX"; 242 case EXCCODE_TLBPE: return "PPI"; 243 case EXCCODE_ADE: 244 switch (esubcode) { 245 case EXSUBCODE_ADEF: return "ADEF"; 246 case EXSUBCODE_ADEM: return "ADEM"; 247 } 248 break; 249 case EXCCODE_ALE: return "ALE"; 250 case EXCCODE_BCE: return "BCE"; 251 case EXCCODE_SYS: return "SYS"; 252 case EXCCODE_BP: return "BRK"; 253 case EXCCODE_INE: return "INE"; 254 case EXCCODE_IPE: return "IPE"; 255 case EXCCODE_FPDIS: return "FPD"; 256 case EXCCODE_LSXDIS: return "SXD"; 257 case EXCCODE_LASXDIS: return "ASXD"; 258 case EXCCODE_FPE: 259 switch (esubcode) { 260 case EXCSUBCODE_FPE: return "FPE"; 261 case EXCSUBCODE_VFPE: return "VFPE"; 262 } 263 break; 264 case EXCCODE_WATCH: 265 switch (esubcode) { 266 case EXCSUBCODE_WPEF: return "WPEF"; 267 case EXCSUBCODE_WPEM: return "WPEM"; 268 } 269 break; 270 case EXCCODE_BTDIS: return "BTD"; 271 case EXCCODE_BTE: return "BTE"; 272 case EXCCODE_GSPR: return "GSPR"; 273 case EXCCODE_HVC: return "HVC"; 274 case EXCCODE_GCM: 275 switch (esubcode) { 276 case EXCSUBCODE_GCSC: return "GCSC"; 277 case EXCSUBCODE_GCHC: return "GCHC"; 278 } 279 break; 280 /* 281 * The manual did not mention the EXCCODE_SE case, but print out it 282 * nevertheless. 283 */ 284 case EXCCODE_SE: return "SE"; 285 } 286 287 return "???"; 288 } 289 290 static void print_estat(unsigned long x) 291 { 292 unsigned int ecode = FIELD_GET(CSR_ESTAT_EXC, x); 293 unsigned int esubcode = FIELD_GET(CSR_ESTAT_ESUBCODE, x); 294 295 printk("ESTAT: %08lx [%s] (", x, humanize_exc_name(ecode, esubcode)); 296 print_intr_fragment("IS", FIELD_GET(CSR_ESTAT_IS, x)); 297 pr_cont(" ECode=%d EsubCode=%d)\n", (int) ecode, (int) esubcode); 298 } 299 300 static void __show_regs(const struct pt_regs *regs) 301 { 302 const int field = 2 * sizeof(unsigned long); 303 unsigned int exccode = FIELD_GET(CSR_ESTAT_EXC, regs->csr_estat); 304 305 show_regs_print_info(KERN_DEFAULT); 306 307 /* Print saved GPRs except $zero (substituting with PC/ERA) */ 308 #define GPR_FIELD(x) field, regs->regs[x] 309 printk("pc %0*lx ra %0*lx tp %0*lx sp %0*lx\n", 310 field, regs->csr_era, GPR_FIELD(1), GPR_FIELD(2), GPR_FIELD(3)); 311 printk("a0 %0*lx a1 %0*lx a2 %0*lx a3 %0*lx\n", 312 GPR_FIELD(4), GPR_FIELD(5), GPR_FIELD(6), GPR_FIELD(7)); 313 printk("a4 %0*lx a5 %0*lx a6 %0*lx a7 %0*lx\n", 314 GPR_FIELD(8), GPR_FIELD(9), GPR_FIELD(10), GPR_FIELD(11)); 315 printk("t0 %0*lx t1 %0*lx t2 %0*lx t3 %0*lx\n", 316 GPR_FIELD(12), GPR_FIELD(13), GPR_FIELD(14), GPR_FIELD(15)); 317 printk("t4 %0*lx t5 %0*lx t6 %0*lx t7 %0*lx\n", 318 GPR_FIELD(16), GPR_FIELD(17), GPR_FIELD(18), GPR_FIELD(19)); 319 printk("t8 %0*lx u0 %0*lx s9 %0*lx s0 %0*lx\n", 320 GPR_FIELD(20), GPR_FIELD(21), GPR_FIELD(22), GPR_FIELD(23)); 321 printk("s1 %0*lx s2 %0*lx s3 %0*lx s4 %0*lx\n", 322 GPR_FIELD(24), GPR_FIELD(25), GPR_FIELD(26), GPR_FIELD(27)); 323 printk("s5 %0*lx s6 %0*lx s7 %0*lx s8 %0*lx\n", 324 GPR_FIELD(28), GPR_FIELD(29), GPR_FIELD(30), GPR_FIELD(31)); 325 326 /* The slot for $zero is reused as the syscall restart flag */ 327 if (regs->regs[0]) 328 printk("syscall restart flag: %0*lx\n", GPR_FIELD(0)); 329 330 if (user_mode(regs)) { 331 printk(" ra: %0*lx\n", GPR_FIELD(1)); 332 printk(" ERA: %0*lx\n", field, regs->csr_era); 333 } else { 334 printk(" ra: %0*lx %pS\n", GPR_FIELD(1), (void *) regs->regs[1]); 335 printk(" ERA: %0*lx %pS\n", field, regs->csr_era, (void *) regs->csr_era); 336 } 337 #undef GPR_FIELD 338 339 /* Print saved important CSRs */ 340 print_crmd(regs->csr_crmd); 341 print_prmd(regs->csr_prmd); 342 print_euen(regs->csr_euen); 343 print_ecfg(regs->csr_ecfg); 344 print_estat(regs->csr_estat); 345 346 if (exccode >= EXCCODE_TLBL && exccode <= EXCCODE_ALE) 347 printk(" BADV: %0*lx\n", field, regs->csr_badvaddr); 348 349 printk(" PRID: %08x (%s, %s)\n", read_cpucfg(LOONGARCH_CPUCFG0), 350 cpu_family_string(), cpu_full_name_string()); 351 } 352 353 void show_regs(struct pt_regs *regs) 354 { 355 __show_regs((struct pt_regs *)regs); 356 dump_stack(); 357 } 358 359 void show_registers(struct pt_regs *regs) 360 { 361 __show_regs(regs); 362 print_modules(); 363 printk("Process %s (pid: %d, threadinfo=%p, task=%p)\n", 364 current->comm, current->pid, current_thread_info(), current); 365 366 show_stacktrace(current, regs, KERN_DEFAULT, user_mode(regs)); 367 show_code((void *)regs->csr_era, user_mode(regs)); 368 printk("\n"); 369 } 370 371 static DEFINE_RAW_SPINLOCK(die_lock); 372 373 void die(const char *str, struct pt_regs *regs) 374 { 375 int ret; 376 static int die_counter; 377 378 oops_enter(); 379 380 ret = notify_die(DIE_OOPS, str, regs, 0, 381 current->thread.trap_nr, SIGSEGV); 382 383 console_verbose(); 384 raw_spin_lock_irq(&die_lock); 385 bust_spinlocks(1); 386 387 printk("%s[#%d]:\n", str, ++die_counter); 388 show_registers(regs); 389 add_taint(TAINT_DIE, LOCKDEP_NOW_UNRELIABLE); 390 raw_spin_unlock_irq(&die_lock); 391 392 oops_exit(); 393 394 if (ret == NOTIFY_STOP) 395 return; 396 397 if (regs && kexec_should_crash(current)) 398 crash_kexec(regs); 399 400 if (in_interrupt()) 401 panic("Fatal exception in interrupt"); 402 403 if (panic_on_oops) 404 panic("Fatal exception"); 405 406 make_task_dead(SIGSEGV); 407 } 408 409 static inline void setup_vint_size(unsigned int size) 410 { 411 unsigned int vs; 412 413 vs = ilog2(size/4); 414 415 if (vs == 0 || vs > 7) 416 panic("vint_size %d Not support yet", vs); 417 418 csr_xchg32(vs<<CSR_ECFG_VS_SHIFT, CSR_ECFG_VS, LOONGARCH_CSR_ECFG); 419 } 420 421 /* 422 * Send SIGFPE according to FCSR Cause bits, which must have already 423 * been masked against Enable bits. This is impotant as Inexact can 424 * happen together with Overflow or Underflow, and `ptrace' can set 425 * any bits. 426 */ 427 static void force_fcsr_sig(unsigned long fcsr, 428 void __user *fault_addr, struct task_struct *tsk) 429 { 430 int si_code = FPE_FLTUNK; 431 432 if (fcsr & FPU_CSR_INV_X) 433 si_code = FPE_FLTINV; 434 else if (fcsr & FPU_CSR_DIV_X) 435 si_code = FPE_FLTDIV; 436 else if (fcsr & FPU_CSR_OVF_X) 437 si_code = FPE_FLTOVF; 438 else if (fcsr & FPU_CSR_UDF_X) 439 si_code = FPE_FLTUND; 440 else if (fcsr & FPU_CSR_INE_X) 441 si_code = FPE_FLTRES; 442 443 force_sig_fault(SIGFPE, si_code, fault_addr); 444 } 445 446 static int process_fpemu_return(int sig, void __user *fault_addr, unsigned long fcsr) 447 { 448 int si_code; 449 450 switch (sig) { 451 case 0: 452 return 0; 453 454 case SIGFPE: 455 force_fcsr_sig(fcsr, fault_addr, current); 456 return 1; 457 458 case SIGBUS: 459 force_sig_fault(SIGBUS, BUS_ADRERR, fault_addr); 460 return 1; 461 462 case SIGSEGV: 463 mmap_read_lock(current->mm); 464 if (vma_lookup(current->mm, (unsigned long)fault_addr)) 465 si_code = SEGV_ACCERR; 466 else 467 si_code = SEGV_MAPERR; 468 mmap_read_unlock(current->mm); 469 force_sig_fault(SIGSEGV, si_code, fault_addr); 470 return 1; 471 472 default: 473 force_sig(sig); 474 return 1; 475 } 476 } 477 478 /* 479 * Delayed fp exceptions when doing a lazy ctx switch 480 */ 481 asmlinkage void noinstr do_fpe(struct pt_regs *regs, unsigned long fcsr) 482 { 483 int sig; 484 void __user *fault_addr; 485 irqentry_state_t state = irqentry_enter(regs); 486 487 if (notify_die(DIE_FP, "FP exception", regs, 0, current->thread.trap_nr, 488 SIGFPE) == NOTIFY_STOP) 489 goto out; 490 491 /* Clear FCSR.Cause before enabling interrupts */ 492 write_fcsr(LOONGARCH_FCSR0, fcsr & ~mask_fcsr_x(fcsr)); 493 local_irq_enable(); 494 495 die_if_kernel("FP exception in kernel code", regs); 496 497 sig = SIGFPE; 498 fault_addr = (void __user *) regs->csr_era; 499 500 /* Send a signal if required. */ 501 process_fpemu_return(sig, fault_addr, fcsr); 502 503 out: 504 local_irq_disable(); 505 irqentry_exit(regs, state); 506 } 507 508 asmlinkage void noinstr do_ade(struct pt_regs *regs) 509 { 510 irqentry_state_t state = irqentry_enter(regs); 511 512 die_if_kernel("Kernel ade access", regs); 513 force_sig_fault(SIGBUS, BUS_ADRERR, (void __user *)regs->csr_badvaddr); 514 515 irqentry_exit(regs, state); 516 } 517 518 /* sysctl hooks */ 519 int unaligned_enabled __read_mostly = 1; /* Enabled by default */ 520 int no_unaligned_warning __read_mostly = 1; /* Only 1 warning by default */ 521 522 asmlinkage void noinstr do_ale(struct pt_regs *regs) 523 { 524 irqentry_state_t state = irqentry_enter(regs); 525 526 #ifndef CONFIG_ARCH_STRICT_ALIGN 527 die_if_kernel("Kernel ale access", regs); 528 force_sig_fault(SIGBUS, BUS_ADRALN, (void __user *)regs->csr_badvaddr); 529 #else 530 unsigned int *pc; 531 532 perf_sw_event(PERF_COUNT_SW_ALIGNMENT_FAULTS, 1, regs, regs->csr_badvaddr); 533 534 /* 535 * Did we catch a fault trying to load an instruction? 536 */ 537 if (regs->csr_badvaddr == regs->csr_era) 538 goto sigbus; 539 if (user_mode(regs) && !test_thread_flag(TIF_FIXADE)) 540 goto sigbus; 541 if (!unaligned_enabled) 542 goto sigbus; 543 if (!no_unaligned_warning) 544 show_registers(regs); 545 546 pc = (unsigned int *)exception_era(regs); 547 548 emulate_load_store_insn(regs, (void __user *)regs->csr_badvaddr, pc); 549 550 goto out; 551 552 sigbus: 553 die_if_kernel("Kernel ale access", regs); 554 force_sig_fault(SIGBUS, BUS_ADRALN, (void __user *)regs->csr_badvaddr); 555 out: 556 #endif 557 irqentry_exit(regs, state); 558 } 559 560 #ifdef CONFIG_GENERIC_BUG 561 int is_valid_bugaddr(unsigned long addr) 562 { 563 return 1; 564 } 565 #endif /* CONFIG_GENERIC_BUG */ 566 567 static void bug_handler(struct pt_regs *regs) 568 { 569 switch (report_bug(regs->csr_era, regs)) { 570 case BUG_TRAP_TYPE_BUG: 571 case BUG_TRAP_TYPE_NONE: 572 die_if_kernel("Oops - BUG", regs); 573 force_sig(SIGTRAP); 574 break; 575 576 case BUG_TRAP_TYPE_WARN: 577 /* Skip the BUG instruction and continue */ 578 regs->csr_era += LOONGARCH_INSN_SIZE; 579 break; 580 } 581 } 582 583 asmlinkage void noinstr do_bce(struct pt_regs *regs) 584 { 585 bool user = user_mode(regs); 586 unsigned long era = exception_era(regs); 587 u64 badv = 0, lower = 0, upper = ULONG_MAX; 588 union loongarch_instruction insn; 589 irqentry_state_t state = irqentry_enter(regs); 590 591 if (regs->csr_prmd & CSR_PRMD_PIE) 592 local_irq_enable(); 593 594 current->thread.trap_nr = read_csr_excode(); 595 596 die_if_kernel("Bounds check error in kernel code", regs); 597 598 /* 599 * Pull out the address that failed bounds checking, and the lower / 600 * upper bound, by minimally looking at the faulting instruction word 601 * and reading from the correct register. 602 */ 603 if (__get_inst(&insn.word, (u32 *)era, user)) 604 goto bad_era; 605 606 switch (insn.reg3_format.opcode) { 607 case asrtle_op: 608 if (insn.reg3_format.rd != 0) 609 break; /* not asrtle */ 610 badv = regs->regs[insn.reg3_format.rj]; 611 upper = regs->regs[insn.reg3_format.rk]; 612 break; 613 614 case asrtgt_op: 615 if (insn.reg3_format.rd != 0) 616 break; /* not asrtgt */ 617 badv = regs->regs[insn.reg3_format.rj]; 618 lower = regs->regs[insn.reg3_format.rk]; 619 break; 620 621 case ldleb_op: 622 case ldleh_op: 623 case ldlew_op: 624 case ldled_op: 625 case stleb_op: 626 case stleh_op: 627 case stlew_op: 628 case stled_op: 629 case fldles_op: 630 case fldled_op: 631 case fstles_op: 632 case fstled_op: 633 badv = regs->regs[insn.reg3_format.rj]; 634 upper = regs->regs[insn.reg3_format.rk]; 635 break; 636 637 case ldgtb_op: 638 case ldgth_op: 639 case ldgtw_op: 640 case ldgtd_op: 641 case stgtb_op: 642 case stgth_op: 643 case stgtw_op: 644 case stgtd_op: 645 case fldgts_op: 646 case fldgtd_op: 647 case fstgts_op: 648 case fstgtd_op: 649 badv = regs->regs[insn.reg3_format.rj]; 650 lower = regs->regs[insn.reg3_format.rk]; 651 break; 652 } 653 654 force_sig_bnderr((void __user *)badv, (void __user *)lower, (void __user *)upper); 655 656 out: 657 if (regs->csr_prmd & CSR_PRMD_PIE) 658 local_irq_disable(); 659 660 irqentry_exit(regs, state); 661 return; 662 663 bad_era: 664 /* 665 * Cannot pull out the instruction word, hence cannot provide more 666 * info than a regular SIGSEGV in this case. 667 */ 668 force_sig(SIGSEGV); 669 goto out; 670 } 671 672 asmlinkage void noinstr do_bp(struct pt_regs *regs) 673 { 674 bool user = user_mode(regs); 675 unsigned int opcode, bcode; 676 unsigned long era = exception_era(regs); 677 irqentry_state_t state = irqentry_enter(regs); 678 679 if (regs->csr_prmd & CSR_PRMD_PIE) 680 local_irq_enable(); 681 682 if (__get_inst(&opcode, (u32 *)era, user)) 683 goto out_sigsegv; 684 685 bcode = (opcode & 0x7fff); 686 687 /* 688 * notify the kprobe handlers, if instruction is likely to 689 * pertain to them. 690 */ 691 switch (bcode) { 692 case BRK_KDB: 693 if (kgdb_breakpoint_handler(regs)) 694 goto out; 695 else 696 break; 697 case BRK_KPROBE_BP: 698 if (kprobe_breakpoint_handler(regs)) 699 goto out; 700 else 701 break; 702 case BRK_KPROBE_SSTEPBP: 703 if (kprobe_singlestep_handler(regs)) 704 goto out; 705 else 706 break; 707 case BRK_UPROBE_BP: 708 if (uprobe_breakpoint_handler(regs)) 709 goto out; 710 else 711 break; 712 case BRK_UPROBE_XOLBP: 713 if (uprobe_singlestep_handler(regs)) 714 goto out; 715 else 716 break; 717 default: 718 current->thread.trap_nr = read_csr_excode(); 719 if (notify_die(DIE_TRAP, "Break", regs, bcode, 720 current->thread.trap_nr, SIGTRAP) == NOTIFY_STOP) 721 goto out; 722 else 723 break; 724 } 725 726 switch (bcode) { 727 case BRK_BUG: 728 bug_handler(regs); 729 break; 730 case BRK_DIVZERO: 731 die_if_kernel("Break instruction in kernel code", regs); 732 force_sig_fault(SIGFPE, FPE_INTDIV, (void __user *)regs->csr_era); 733 break; 734 case BRK_OVERFLOW: 735 die_if_kernel("Break instruction in kernel code", regs); 736 force_sig_fault(SIGFPE, FPE_INTOVF, (void __user *)regs->csr_era); 737 break; 738 default: 739 die_if_kernel("Break instruction in kernel code", regs); 740 force_sig_fault(SIGTRAP, TRAP_BRKPT, (void __user *)regs->csr_era); 741 break; 742 } 743 744 out: 745 if (regs->csr_prmd & CSR_PRMD_PIE) 746 local_irq_disable(); 747 748 irqentry_exit(regs, state); 749 return; 750 751 out_sigsegv: 752 force_sig(SIGSEGV); 753 goto out; 754 } 755 756 asmlinkage void noinstr do_watch(struct pt_regs *regs) 757 { 758 irqentry_state_t state = irqentry_enter(regs); 759 760 #ifndef CONFIG_HAVE_HW_BREAKPOINT 761 pr_warn("Hardware watch point handler not implemented!\n"); 762 #else 763 if (kgdb_breakpoint_handler(regs)) 764 goto out; 765 766 if (test_tsk_thread_flag(current, TIF_SINGLESTEP)) { 767 int llbit = (csr_read32(LOONGARCH_CSR_LLBCTL) & 0x1); 768 unsigned long pc = instruction_pointer(regs); 769 union loongarch_instruction *ip = (union loongarch_instruction *)pc; 770 771 if (llbit) { 772 /* 773 * When the ll-sc combo is encountered, it is regarded as an single 774 * instruction. So don't clear llbit and reset CSR.FWPS.Skip until 775 * the llsc execution is completed. 776 */ 777 csr_write32(CSR_FWPC_SKIP, LOONGARCH_CSR_FWPS); 778 csr_write32(CSR_LLBCTL_KLO, LOONGARCH_CSR_LLBCTL); 779 goto out; 780 } 781 782 if (pc == current->thread.single_step) { 783 /* 784 * Certain insns are occasionally not skipped when CSR.FWPS.Skip is 785 * set, such as fld.d/fst.d. So singlestep needs to compare whether 786 * the csr_era is equal to the value of singlestep which last time set. 787 */ 788 if (!is_self_loop_ins(ip, regs)) { 789 /* 790 * Check if the given instruction the target pc is equal to the 791 * current pc, If yes, then we should not set the CSR.FWPS.SKIP 792 * bit to break the original instruction stream. 793 */ 794 csr_write32(CSR_FWPC_SKIP, LOONGARCH_CSR_FWPS); 795 goto out; 796 } 797 } 798 } else { 799 breakpoint_handler(regs); 800 watchpoint_handler(regs); 801 } 802 803 force_sig(SIGTRAP); 804 out: 805 #endif 806 irqentry_exit(regs, state); 807 } 808 809 asmlinkage void noinstr do_ri(struct pt_regs *regs) 810 { 811 int status = SIGILL; 812 unsigned int __maybe_unused opcode; 813 unsigned int __user *era = (unsigned int __user *)exception_era(regs); 814 irqentry_state_t state = irqentry_enter(regs); 815 816 local_irq_enable(); 817 current->thread.trap_nr = read_csr_excode(); 818 819 if (notify_die(DIE_RI, "RI Fault", regs, 0, current->thread.trap_nr, 820 SIGILL) == NOTIFY_STOP) 821 goto out; 822 823 die_if_kernel("Reserved instruction in kernel code", regs); 824 825 if (unlikely(get_user(opcode, era) < 0)) { 826 status = SIGSEGV; 827 current->thread.error_code = 1; 828 } 829 830 force_sig(status); 831 832 out: 833 local_irq_disable(); 834 irqentry_exit(regs, state); 835 } 836 837 static void init_restore_fp(void) 838 { 839 if (!used_math()) { 840 /* First time FP context user. */ 841 init_fpu(); 842 } else { 843 /* This task has formerly used the FP context */ 844 if (!is_fpu_owner()) 845 own_fpu_inatomic(1); 846 } 847 848 BUG_ON(!is_fp_enabled()); 849 } 850 851 static void init_restore_lsx(void) 852 { 853 enable_lsx(); 854 855 if (!thread_lsx_context_live()) { 856 /* First time LSX context user */ 857 init_restore_fp(); 858 init_lsx_upper(); 859 set_thread_flag(TIF_LSX_CTX_LIVE); 860 } else { 861 if (!is_simd_owner()) { 862 if (is_fpu_owner()) { 863 restore_lsx_upper(current); 864 } else { 865 __own_fpu(); 866 restore_lsx(current); 867 } 868 } 869 } 870 871 set_thread_flag(TIF_USEDSIMD); 872 873 BUG_ON(!is_fp_enabled()); 874 BUG_ON(!is_lsx_enabled()); 875 } 876 877 static void init_restore_lasx(void) 878 { 879 enable_lasx(); 880 881 if (!thread_lasx_context_live()) { 882 /* First time LASX context user */ 883 init_restore_lsx(); 884 init_lasx_upper(); 885 set_thread_flag(TIF_LASX_CTX_LIVE); 886 } else { 887 if (is_fpu_owner() || is_simd_owner()) { 888 init_restore_lsx(); 889 restore_lasx_upper(current); 890 } else { 891 __own_fpu(); 892 enable_lsx(); 893 restore_lasx(current); 894 } 895 } 896 897 set_thread_flag(TIF_USEDSIMD); 898 899 BUG_ON(!is_fp_enabled()); 900 BUG_ON(!is_lsx_enabled()); 901 BUG_ON(!is_lasx_enabled()); 902 } 903 904 asmlinkage void noinstr do_fpu(struct pt_regs *regs) 905 { 906 irqentry_state_t state = irqentry_enter(regs); 907 908 local_irq_enable(); 909 die_if_kernel("do_fpu invoked from kernel context!", regs); 910 BUG_ON(is_lsx_enabled()); 911 BUG_ON(is_lasx_enabled()); 912 913 preempt_disable(); 914 init_restore_fp(); 915 preempt_enable(); 916 917 local_irq_disable(); 918 irqentry_exit(regs, state); 919 } 920 921 asmlinkage void noinstr do_lsx(struct pt_regs *regs) 922 { 923 irqentry_state_t state = irqentry_enter(regs); 924 925 local_irq_enable(); 926 if (!cpu_has_lsx) { 927 force_sig(SIGILL); 928 goto out; 929 } 930 931 die_if_kernel("do_lsx invoked from kernel context!", regs); 932 BUG_ON(is_lasx_enabled()); 933 934 preempt_disable(); 935 init_restore_lsx(); 936 preempt_enable(); 937 938 out: 939 local_irq_disable(); 940 irqentry_exit(regs, state); 941 } 942 943 asmlinkage void noinstr do_lasx(struct pt_regs *regs) 944 { 945 irqentry_state_t state = irqentry_enter(regs); 946 947 local_irq_enable(); 948 if (!cpu_has_lasx) { 949 force_sig(SIGILL); 950 goto out; 951 } 952 953 die_if_kernel("do_lasx invoked from kernel context!", regs); 954 955 preempt_disable(); 956 init_restore_lasx(); 957 preempt_enable(); 958 959 out: 960 local_irq_disable(); 961 irqentry_exit(regs, state); 962 } 963 964 static void init_restore_lbt(void) 965 { 966 if (!thread_lbt_context_live()) { 967 /* First time LBT context user */ 968 init_lbt(); 969 set_thread_flag(TIF_LBT_CTX_LIVE); 970 } else { 971 if (!is_lbt_owner()) 972 own_lbt_inatomic(1); 973 } 974 975 BUG_ON(!is_lbt_enabled()); 976 } 977 978 asmlinkage void noinstr do_lbt(struct pt_regs *regs) 979 { 980 irqentry_state_t state = irqentry_enter(regs); 981 982 /* 983 * BTD (Binary Translation Disable exception) can be triggered 984 * during FP save/restore if TM (Top Mode) is on, which may 985 * cause irq_enable during 'switch_to'. To avoid this situation 986 * (including the user using 'MOVGR2GCSR' to turn on TM, which 987 * will not trigger the BTE), we need to check PRMD first. 988 */ 989 if (regs->csr_prmd & CSR_PRMD_PIE) 990 local_irq_enable(); 991 992 if (!cpu_has_lbt) { 993 force_sig(SIGILL); 994 goto out; 995 } 996 BUG_ON(is_lbt_enabled()); 997 998 preempt_disable(); 999 init_restore_lbt(); 1000 preempt_enable(); 1001 1002 out: 1003 if (regs->csr_prmd & CSR_PRMD_PIE) 1004 local_irq_disable(); 1005 1006 irqentry_exit(regs, state); 1007 } 1008 1009 asmlinkage void noinstr do_reserved(struct pt_regs *regs) 1010 { 1011 irqentry_state_t state = irqentry_enter(regs); 1012 1013 local_irq_enable(); 1014 /* 1015 * Game over - no way to handle this if it ever occurs. Most probably 1016 * caused by a fatal error after another hardware/software error. 1017 */ 1018 pr_err("Caught reserved exception %u on pid:%d [%s] - should not happen\n", 1019 read_csr_excode(), current->pid, current->comm); 1020 die_if_kernel("do_reserved exception", regs); 1021 force_sig(SIGUNUSED); 1022 1023 local_irq_disable(); 1024 1025 irqentry_exit(regs, state); 1026 } 1027 1028 asmlinkage void cache_parity_error(void) 1029 { 1030 /* For the moment, report the problem and hang. */ 1031 pr_err("Cache error exception:\n"); 1032 pr_err("csr_merrctl == %08x\n", csr_read32(LOONGARCH_CSR_MERRCTL)); 1033 pr_err("csr_merrera == %016lx\n", csr_read64(LOONGARCH_CSR_MERRERA)); 1034 panic("Can't handle the cache error!"); 1035 } 1036 1037 asmlinkage void noinstr handle_loongarch_irq(struct pt_regs *regs) 1038 { 1039 struct pt_regs *old_regs; 1040 1041 irq_enter_rcu(); 1042 old_regs = set_irq_regs(regs); 1043 handle_arch_irq(regs); 1044 set_irq_regs(old_regs); 1045 irq_exit_rcu(); 1046 } 1047 1048 asmlinkage void noinstr do_vint(struct pt_regs *regs, unsigned long sp) 1049 { 1050 register int cpu; 1051 register unsigned long stack; 1052 irqentry_state_t state = irqentry_enter(regs); 1053 1054 cpu = smp_processor_id(); 1055 1056 if (on_irq_stack(cpu, sp)) 1057 handle_loongarch_irq(regs); 1058 else { 1059 stack = per_cpu(irq_stack, cpu) + IRQ_STACK_START; 1060 1061 /* Save task's sp on IRQ stack for unwinding */ 1062 *(unsigned long *)stack = sp; 1063 1064 __asm__ __volatile__( 1065 "move $s0, $sp \n" /* Preserve sp */ 1066 "move $sp, %[stk] \n" /* Switch stack */ 1067 "move $a0, %[regs] \n" 1068 "bl handle_loongarch_irq \n" 1069 "move $sp, $s0 \n" /* Restore sp */ 1070 : /* No outputs */ 1071 : [stk] "r" (stack), [regs] "r" (regs) 1072 : "$a0", "$a1", "$a2", "$a3", "$a4", "$a5", "$a6", "$a7", "$s0", 1073 "$t0", "$t1", "$t2", "$t3", "$t4", "$t5", "$t6", "$t7", "$t8", 1074 "memory"); 1075 } 1076 1077 irqentry_exit(regs, state); 1078 } 1079 1080 unsigned long eentry; 1081 unsigned long tlbrentry; 1082 1083 long exception_handlers[VECSIZE * 128 / sizeof(long)] __aligned(SZ_64K); 1084 1085 static void configure_exception_vector(void) 1086 { 1087 eentry = (unsigned long)exception_handlers; 1088 tlbrentry = (unsigned long)exception_handlers + 80*VECSIZE; 1089 1090 csr_write64(eentry, LOONGARCH_CSR_EENTRY); 1091 csr_write64(eentry, LOONGARCH_CSR_MERRENTRY); 1092 csr_write64(tlbrentry, LOONGARCH_CSR_TLBRENTRY); 1093 } 1094 1095 void per_cpu_trap_init(int cpu) 1096 { 1097 unsigned int i; 1098 1099 setup_vint_size(VECSIZE); 1100 1101 configure_exception_vector(); 1102 1103 if (!cpu_data[cpu].asid_cache) 1104 cpu_data[cpu].asid_cache = asid_first_version(cpu); 1105 1106 mmgrab(&init_mm); 1107 current->active_mm = &init_mm; 1108 BUG_ON(current->mm); 1109 enter_lazy_tlb(&init_mm, current); 1110 1111 /* Initialise exception handlers */ 1112 if (cpu == 0) 1113 for (i = 0; i < 64; i++) 1114 set_handler(i * VECSIZE, handle_reserved, VECSIZE); 1115 1116 tlb_init(cpu); 1117 cpu_cache_init(); 1118 } 1119 1120 /* Install CPU exception handler */ 1121 void set_handler(unsigned long offset, void *addr, unsigned long size) 1122 { 1123 memcpy((void *)(eentry + offset), addr, size); 1124 local_flush_icache_range(eentry + offset, eentry + offset + size); 1125 } 1126 1127 static const char panic_null_cerr[] = 1128 "Trying to set NULL cache error exception handler\n"; 1129 1130 /* 1131 * Install uncached CPU exception handler. 1132 * This is suitable only for the cache error exception which is the only 1133 * exception handler that is being run uncached. 1134 */ 1135 void set_merr_handler(unsigned long offset, void *addr, unsigned long size) 1136 { 1137 unsigned long uncached_eentry = TO_UNCACHE(__pa(eentry)); 1138 1139 if (!addr) 1140 panic(panic_null_cerr); 1141 1142 memcpy((void *)(uncached_eentry + offset), addr, size); 1143 } 1144 1145 void __init trap_init(void) 1146 { 1147 long i; 1148 1149 /* Set interrupt vector handler */ 1150 for (i = EXCCODE_INT_START; i <= EXCCODE_INT_END; i++) 1151 set_handler(i * VECSIZE, handle_vint, VECSIZE); 1152 1153 set_handler(EXCCODE_ADE * VECSIZE, handle_ade, VECSIZE); 1154 set_handler(EXCCODE_ALE * VECSIZE, handle_ale, VECSIZE); 1155 set_handler(EXCCODE_BCE * VECSIZE, handle_bce, VECSIZE); 1156 set_handler(EXCCODE_SYS * VECSIZE, handle_sys, VECSIZE); 1157 set_handler(EXCCODE_BP * VECSIZE, handle_bp, VECSIZE); 1158 set_handler(EXCCODE_INE * VECSIZE, handle_ri, VECSIZE); 1159 set_handler(EXCCODE_IPE * VECSIZE, handle_ri, VECSIZE); 1160 set_handler(EXCCODE_FPDIS * VECSIZE, handle_fpu, VECSIZE); 1161 set_handler(EXCCODE_LSXDIS * VECSIZE, handle_lsx, VECSIZE); 1162 set_handler(EXCCODE_LASXDIS * VECSIZE, handle_lasx, VECSIZE); 1163 set_handler(EXCCODE_FPE * VECSIZE, handle_fpe, VECSIZE); 1164 set_handler(EXCCODE_BTDIS * VECSIZE, handle_lbt, VECSIZE); 1165 set_handler(EXCCODE_WATCH * VECSIZE, handle_watch, VECSIZE); 1166 1167 cache_error_setup(); 1168 1169 local_flush_icache_range(eentry, eentry + 0x400); 1170 } 1171