Now available: The Design and Implementation of the FreeBSD Operating System (Second Edition)
[ source navigation ] [ diff markup ] [ identifier search ] [ freetext search ] [ file search ] [ list types ] [ track identifier ]
FreeBSD/Linux Kernel Cross Reference
sys/amd64/amd64/db_trace.c
Version:
- FREEBSD - FREEBSD-13-STABLE - FREEBSD-13-0 - FREEBSD-12-STABLE - FREEBSD-12-0 - FREEBSD-11-STABLE - FREEBSD-11-0 - FREEBSD-10-STABLE - FREEBSD-10-0 - FREEBSD-9-STABLE - FREEBSD-9-0 - FREEBSD-8-STABLE - FREEBSD-8-0 - FREEBSD-7-STABLE - FREEBSD-7-0 - FREEBSD-6-STABLE - FREEBSD-6-0 - FREEBSD-5-STABLE - FREEBSD-5-0 - FREEBSD-4-STABLE - FREEBSD-3-STABLE - FREEBSD22 - l41 - OPENBSD - linux-2.6 - MK84 - PLAN9 - xnu-8792
SearchContext: - none - 3 - 10
SearchContext: - none - 3 - 10
1 /*- 2 * Mach Operating System 3 * Copyright (c) 1991,1990 Carnegie Mellon University 4 * All Rights Reserved. 5 * 6 * Permission to use, copy, modify and distribute this software and its 7 * documentation is hereby granted, provided that both the copyright 8 * notice and this permission notice appear in all copies of the 9 * software, derivative works or modified versions, and any portions 10 * thereof, and that both notices appear in supporting documentation. 11 * 12 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS 13 * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR 14 * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE. 15 * 16 * Carnegie Mellon requests users of this software to return to 17 * 18 * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU 19 * School of Computer Science 20 * Carnegie Mellon University 21 * Pittsburgh PA 15213-3890 22 * 23 * any improvements or extensions that they make and grant Carnegie the 24 * rights to redistribute these changes. 25 */ 26 27 #include <sys/cdefs.h> 28 __FBSDID("$FreeBSD$"); 29 30 #include <sys/param.h> 31 #include <sys/systm.h> 32 #include <sys/kdb.h> 33 #include <sys/proc.h> 34 #include <sys/smp.h> 35 #include <sys/stack.h> 36 #include <sys/sysent.h> 37 38 #include <machine/cpu.h> 39 #include <machine/md_var.h> 40 #include <machine/pcb.h> 41 #include <machine/reg.h> 42 #include <machine/stack.h> 43 44 #include <vm/vm.h> 45 #include <vm/vm_param.h> 46 #include <vm/pmap.h> 47 48 #include <ddb/ddb.h> 49 #include <ddb/db_access.h> 50 #include <ddb/db_sym.h> 51 #include <ddb/db_variables.h> 52 53 static db_varfcn_t db_frame; 54 static db_varfcn_t db_frame_seg; 55 56 CTASSERT(sizeof(struct dbreg) == sizeof(((struct pcpu *)NULL)->pc_dbreg)); 57 58 /* 59 * Machine register set. 60 */ 61 #define DB_OFFSET(x) (db_expr_t *)offsetof(struct trapframe, x) 62 struct db_variable db_regs[] = { 63 { "cs", DB_OFFSET(tf_cs), db_frame_seg }, 64 { "ds", DB_OFFSET(tf_ds), db_frame_seg }, 65 { "es", DB_OFFSET(tf_es), db_frame_seg }, 66 { "fs", DB_OFFSET(tf_fs), db_frame_seg }, 67 { "gs", DB_OFFSET(tf_gs), db_frame_seg }, 68 { "ss", DB_OFFSET(tf_ss), db_frame_seg }, 69 { "rax", DB_OFFSET(tf_rax), db_frame }, 70 { "rcx", DB_OFFSET(tf_rcx), db_frame }, 71 { "rdx", DB_OFFSET(tf_rdx), db_frame }, 72 { "rbx", DB_OFFSET(tf_rbx), db_frame }, 73 { "rsp", DB_OFFSET(tf_rsp), db_frame }, 74 { "rbp", DB_OFFSET(tf_rbp), db_frame }, 75 { "rsi", DB_OFFSET(tf_rsi), db_frame }, 76 { "rdi", DB_OFFSET(tf_rdi), db_frame }, 77 { "r8", DB_OFFSET(tf_r8), db_frame }, 78 { "r9", DB_OFFSET(tf_r9), db_frame }, 79 { "r10", DB_OFFSET(tf_r10), db_frame }, 80 { "r11", DB_OFFSET(tf_r11), db_frame }, 81 { "r12", DB_OFFSET(tf_r12), db_frame }, 82 { "r13", DB_OFFSET(tf_r13), db_frame }, 83 { "r14", DB_OFFSET(tf_r14), db_frame }, 84 { "r15", DB_OFFSET(tf_r15), db_frame }, 85 { "rip", DB_OFFSET(tf_rip), db_frame }, 86 { "rflags", DB_OFFSET(tf_rflags), db_frame }, 87 }; 88 struct db_variable *db_eregs = db_regs + nitems(db_regs); 89 90 static int 91 db_frame_seg(struct db_variable *vp, db_expr_t *valuep, int op) 92 { 93 uint16_t *reg; 94 95 if (kdb_frame == NULL) 96 return (0); 97 98 reg = (uint16_t *)((uintptr_t)kdb_frame + (db_expr_t)vp->valuep); 99 if (op == DB_VAR_GET) 100 *valuep = *reg; 101 else 102 *reg = *valuep; 103 return (1); 104 } 105 106 static int 107 db_frame(struct db_variable *vp, db_expr_t *valuep, int op) 108 { 109 long *reg; 110 111 if (kdb_frame == NULL) 112 return (0); 113 114 reg = (long *)((uintptr_t)kdb_frame + (db_expr_t)vp->valuep); 115 if (op == DB_VAR_GET) 116 *valuep = *reg; 117 else 118 *reg = *valuep; 119 return (1); 120 } 121 122 #define NORMAL 0 123 #define TRAP 1 124 #define INTERRUPT 2 125 #define SYSCALL 3 126 127 static void db_nextframe(struct amd64_frame **, db_addr_t *, struct thread *); 128 static void db_print_stack_entry(const char *, db_addr_t, void *); 129 static void decode_syscall(int, struct thread *); 130 131 static const char * watchtype_str(int type); 132 int amd64_set_watch(int watchnum, unsigned long watchaddr, int size, 133 int access, struct dbreg *d); 134 int amd64_clr_watch(int watchnum, struct dbreg *d); 135 136 static void 137 db_print_stack_entry(const char *name, db_addr_t callpc, void *frame) 138 { 139 140 db_printf("%s() at ", name != NULL ? name : "??"); 141 db_printsym(callpc, DB_STGY_PROC); 142 if (frame != NULL) 143 db_printf("/frame 0x%lx", (register_t)frame); 144 db_printf("\n"); 145 } 146 147 static void 148 decode_syscall(int number, struct thread *td) 149 { 150 struct proc *p; 151 c_db_sym_t sym; 152 db_expr_t diff; 153 sy_call_t *f; 154 const char *symname; 155 156 db_printf(" (%d", number); 157 p = (td != NULL) ? td->td_proc : NULL; 158 if (p != NULL && 0 <= number && number < p->p_sysent->sv_size) { 159 f = p->p_sysent->sv_table[number].sy_call; 160 sym = db_search_symbol((db_addr_t)f, DB_STGY_ANY, &diff); 161 if (sym != DB_SYM_NULL && diff == 0) { 162 db_symbol_values(sym, &symname, NULL); 163 db_printf(", %s, %s", p->p_sysent->sv_name, symname); 164 } 165 } 166 db_printf(")"); 167 } 168 169 /* 170 * Figure out the next frame up in the call stack. 171 */ 172 static void 173 db_nextframe(struct amd64_frame **fp, db_addr_t *ip, struct thread *td) 174 { 175 struct trapframe *tf; 176 int frame_type; 177 long rip, rsp, rbp; 178 db_expr_t offset; 179 c_db_sym_t sym; 180 const char *name; 181 182 rip = db_get_value((long) &(*fp)->f_retaddr, 8, FALSE); 183 rbp = db_get_value((long) &(*fp)->f_frame, 8, FALSE); 184 185 /* 186 * Figure out frame type. We look at the address just before 187 * the saved instruction pointer as the saved EIP is after the 188 * call function, and if the function being called is marked as 189 * dead (such as panic() at the end of dblfault_handler()), then 190 * the instruction at the saved EIP will be part of a different 191 * function (syscall() in this example) rather than the one that 192 * actually made the call. 193 */ 194 frame_type = NORMAL; 195 sym = db_search_symbol(rip - 1, DB_STGY_ANY, &offset); 196 db_symbol_values(sym, &name, NULL); 197 if (name != NULL) { 198 if (strcmp(name, "calltrap") == 0 || 199 strcmp(name, "fork_trampoline") == 0 || 200 strcmp(name, "mchk_calltrap") == 0 || 201 strcmp(name, "nmi_calltrap") == 0 || 202 strcmp(name, "Xdblfault") == 0) 203 frame_type = TRAP; 204 else if (strncmp(name, "Xatpic_intr", 11) == 0 || 205 strncmp(name, "Xapic_isr", 9) == 0 || 206 strcmp(name, "Xxen_intr_upcall") == 0 || 207 strcmp(name, "Xtimerint") == 0 || 208 strcmp(name, "Xipi_intr_bitmap_handler") == 0 || 209 strcmp(name, "Xcpustop") == 0 || 210 strcmp(name, "Xcpususpend") == 0 || 211 strcmp(name, "Xrendezvous") == 0) 212 frame_type = INTERRUPT; 213 else if (strcmp(name, "Xfast_syscall") == 0 || 214 strcmp(name, "Xfast_syscall_pti") == 0 || 215 strcmp(name, "fast_syscall_common") == 0) 216 frame_type = SYSCALL; 217 #ifdef COMPAT_FREEBSD32 218 else if (strcmp(name, "Xint0x80_syscall") == 0) 219 frame_type = SYSCALL; 220 #endif 221 } 222 223 /* 224 * Normal frames need no special processing. 225 */ 226 if (frame_type == NORMAL) { 227 *ip = (db_addr_t) rip; 228 *fp = (struct amd64_frame *) rbp; 229 return; 230 } 231 232 db_print_stack_entry(name, rip, &(*fp)->f_frame); 233 234 /* 235 * Point to base of trapframe which is just above the 236 * current frame. 237 */ 238 tf = (struct trapframe *)((long)*fp + 16); 239 240 if (INKERNEL((long) tf)) { 241 rsp = tf->tf_rsp; 242 rip = tf->tf_rip; 243 rbp = tf->tf_rbp; 244 switch (frame_type) { 245 case TRAP: 246 db_printf("--- trap %#r", tf->tf_trapno); 247 break; 248 case SYSCALL: 249 db_printf("--- syscall"); 250 decode_syscall(tf->tf_rax, td); 251 break; 252 case INTERRUPT: 253 db_printf("--- interrupt"); 254 break; 255 default: 256 panic("The moon has moved again."); 257 } 258 db_printf(", rip = %#lr, rsp = %#lr, rbp = %#lr ---\n", rip, 259 rsp, rbp); 260 } 261 262 *ip = (db_addr_t) rip; 263 *fp = (struct amd64_frame *) rbp; 264 } 265 266 static int 267 db_backtrace(struct thread *td, struct trapframe *tf, struct amd64_frame *frame, 268 db_addr_t pc, register_t sp, int count) 269 { 270 struct amd64_frame *actframe; 271 const char *name; 272 db_expr_t offset; 273 c_db_sym_t sym; 274 boolean_t first; 275 276 if (count == -1) 277 count = 1024; 278 279 first = TRUE; 280 while (count-- && !db_pager_quit) { 281 sym = db_search_symbol(pc, DB_STGY_ANY, &offset); 282 db_symbol_values(sym, &name, NULL); 283 284 /* 285 * Attempt to determine a (possibly fake) frame that gives 286 * the caller's pc. It may differ from `frame' if the 287 * current function never sets up a standard frame or hasn't 288 * set one up yet or has just discarded one. The last two 289 * cases can be guessed fairly reliably for code generated 290 * by gcc. The first case is too much trouble to handle in 291 * general because the amount of junk on the stack depends 292 * on the pc (the special handling of "calltrap", etc. in 293 * db_nextframe() works because the `next' pc is special). 294 */ 295 actframe = frame; 296 if (first) { 297 first = FALSE; 298 if (sym == C_DB_SYM_NULL && sp != 0) { 299 /* 300 * If a symbol couldn't be found, we've probably 301 * jumped to a bogus location, so try and use 302 * the return address to find our caller. 303 */ 304 db_print_stack_entry(name, pc, NULL); 305 pc = db_get_value(sp, 8, FALSE); 306 if (db_search_symbol(pc, DB_STGY_PROC, 307 &offset) == C_DB_SYM_NULL) 308 break; 309 continue; 310 } else if (tf != NULL) { 311 int instr; 312 313 instr = db_get_value(pc, 4, FALSE); 314 if ((instr & 0xffffffff) == 0xe5894855) { 315 /* pushq %rbp; movq %rsp, %rbp */ 316 actframe = (void *)(tf->tf_rsp - 8); 317 } else if ((instr & 0xffffff) == 0xe58948) { 318 /* movq %rsp, %rbp */ 319 actframe = (void *)tf->tf_rsp; 320 if (tf->tf_rbp == 0) { 321 /* Fake frame better. */ 322 frame = actframe; 323 } 324 } else if ((instr & 0xff) == 0xc3) { 325 /* ret */ 326 actframe = (void *)(tf->tf_rsp - 8); 327 } else if (offset == 0) { 328 /* Probably an assembler symbol. */ 329 actframe = (void *)(tf->tf_rsp - 8); 330 } 331 } else if (name != NULL && 332 strcmp(name, "fork_trampoline") == 0) { 333 /* 334 * Don't try to walk back on a stack for a 335 * process that hasn't actually been run yet. 336 */ 337 db_print_stack_entry(name, pc, actframe); 338 break; 339 } 340 } 341 342 db_print_stack_entry(name, pc, actframe); 343 344 if (actframe != frame) { 345 /* `frame' belongs to caller. */ 346 pc = (db_addr_t) 347 db_get_value((long)&actframe->f_retaddr, 8, FALSE); 348 continue; 349 } 350 351 db_nextframe(&frame, &pc, td); 352 353 if (INKERNEL((long)pc) && !INKERNEL((long)frame)) { 354 sym = db_search_symbol(pc, DB_STGY_ANY, &offset); 355 db_symbol_values(sym, &name, NULL); 356 db_print_stack_entry(name, pc, frame); 357 break; 358 } 359 if (!INKERNEL((long) frame)) { 360 break; 361 } 362 } 363 364 return (0); 365 } 366 367 void 368 db_trace_self(void) 369 { 370 struct amd64_frame *frame; 371 db_addr_t callpc; 372 register_t rbp; 373 374 __asm __volatile("movq %%rbp,%0" : "=r" (rbp)); 375 frame = (struct amd64_frame *)rbp; 376 callpc = (db_addr_t)db_get_value((long)&frame->f_retaddr, 8, FALSE); 377 frame = frame->f_frame; 378 db_backtrace(curthread, NULL, frame, callpc, 0, -1); 379 } 380 381 int 382 db_trace_thread(struct thread *thr, int count) 383 { 384 struct pcb *ctx; 385 struct trapframe *tf; 386 387 ctx = kdb_thr_ctx(thr); 388 tf = thr == kdb_thread ? kdb_frame : NULL; 389 return (db_backtrace(thr, tf, (struct amd64_frame *)ctx->pcb_rbp, 390 ctx->pcb_rip, ctx->pcb_rsp, count)); 391 } 392 393 int 394 amd64_set_watch(watchnum, watchaddr, size, access, d) 395 int watchnum; 396 unsigned long watchaddr; 397 int size; 398 int access; 399 struct dbreg *d; 400 { 401 int i, len; 402 403 if (watchnum == -1) { 404 for (i = 0; i < 4; i++) 405 if (!DBREG_DR7_ENABLED(d->dr[7], i)) 406 break; 407 if (i < 4) 408 watchnum = i; 409 else 410 return (-1); 411 } 412 413 switch (access) { 414 case DBREG_DR7_EXEC: 415 size = 1; /* size must be 1 for an execution breakpoint */ 416 /* fall through */ 417 case DBREG_DR7_WRONLY: 418 case DBREG_DR7_RDWR: 419 break; 420 default: 421 return (-1); 422 } 423 424 /* 425 * we can watch a 1, 2, 4, or 8 byte sized location 426 */ 427 switch (size) { 428 case 1: 429 len = DBREG_DR7_LEN_1; 430 break; 431 case 2: 432 len = DBREG_DR7_LEN_2; 433 break; 434 case 4: 435 len = DBREG_DR7_LEN_4; 436 break; 437 case 8: 438 len = DBREG_DR7_LEN_8; 439 break; 440 default: 441 return (-1); 442 } 443 444 /* clear the bits we are about to affect */ 445 d->dr[7] &= ~DBREG_DR7_MASK(watchnum); 446 447 /* set drN register to the address, N=watchnum */ 448 DBREG_DRX(d, watchnum) = watchaddr; 449 450 /* enable the watchpoint */ 451 d->dr[7] |= DBREG_DR7_SET(watchnum, len, access, 452 DBREG_DR7_GLOBAL_ENABLE); 453 454 return (watchnum); 455 } 456 457 458 int 459 amd64_clr_watch(watchnum, d) 460 int watchnum; 461 struct dbreg *d; 462 { 463 464 if (watchnum < 0 || watchnum >= 4) 465 return (-1); 466 467 d->dr[7] &= ~DBREG_DR7_MASK(watchnum); 468 DBREG_DRX(d, watchnum) = 0; 469 470 return (0); 471 } 472 473 474 int 475 db_md_set_watchpoint(addr, size) 476 db_expr_t addr; 477 db_expr_t size; 478 { 479 struct dbreg *d; 480 struct pcpu *pc; 481 int avail, c, cpu, i, wsize; 482 483 d = (struct dbreg *)PCPU_PTR(dbreg); 484 cpu = PCPU_GET(cpuid); 485 fill_dbregs(NULL, d); 486 487 avail = 0; 488 for (i = 0; i < 4; i++) { 489 if (!DBREG_DR7_ENABLED(d->dr[7], i)) 490 avail++; 491 } 492 493 if (avail * 8 < size) 494 return (-1); 495 496 for (i = 0; i < 4 && size > 0; i++) { 497 if (!DBREG_DR7_ENABLED(d->dr[7], i)) { 498 if (size >= 8 || (avail == 1 && size > 4)) 499 wsize = 8; 500 else if (size > 2) 501 wsize = 4; 502 else 503 wsize = size; 504 amd64_set_watch(i, addr, wsize, DBREG_DR7_WRONLY, d); 505 addr += wsize; 506 size -= wsize; 507 avail--; 508 } 509 } 510 511 set_dbregs(NULL, d); 512 CPU_FOREACH(c) { 513 if (c == cpu) 514 continue; 515 pc = pcpu_find(c); 516 memcpy(pc->pc_dbreg, d, sizeof(*d)); 517 pc->pc_dbreg_cmd = PC_DBREG_CMD_LOAD; 518 } 519 520 return (0); 521 } 522 523 int 524 db_md_clr_watchpoint(addr, size) 525 db_expr_t addr; 526 db_expr_t size; 527 { 528 struct dbreg *d; 529 struct pcpu *pc; 530 int i, c, cpu; 531 532 d = (struct dbreg *)PCPU_PTR(dbreg); 533 cpu = PCPU_GET(cpuid); 534 fill_dbregs(NULL, d); 535 536 for (i = 0; i < 4; i++) { 537 if (DBREG_DR7_ENABLED(d->dr[7], i)) { 538 if (DBREG_DRX((d), i) >= addr && 539 DBREG_DRX((d), i) < addr + size) 540 amd64_clr_watch(i, d); 541 542 } 543 } 544 545 set_dbregs(NULL, d); 546 CPU_FOREACH(c) { 547 if (c == cpu) 548 continue; 549 pc = pcpu_find(c); 550 memcpy(pc->pc_dbreg, d, sizeof(*d)); 551 pc->pc_dbreg_cmd = PC_DBREG_CMD_LOAD; 552 } 553 554 return (0); 555 } 556 557 558 static const char * 559 watchtype_str(type) 560 int type; 561 { 562 switch (type) { 563 case DBREG_DR7_EXEC : return "execute"; break; 564 case DBREG_DR7_RDWR : return "read/write"; break; 565 case DBREG_DR7_WRONLY : return "write"; break; 566 default : return "invalid"; break; 567 } 568 } 569 570 571 void 572 db_md_list_watchpoints(void) 573 { 574 struct dbreg d; 575 int i, len, type; 576 577 fill_dbregs(NULL, &d); 578 579 db_printf("\nhardware watchpoints:\n"); 580 db_printf(" watch status type len address\n"); 581 db_printf(" ----- -------- ---------- --- ------------------\n"); 582 for (i = 0; i < 4; i++) { 583 if (DBREG_DR7_ENABLED(d.dr[7], i)) { 584 type = DBREG_DR7_ACCESS(d.dr[7], i); 585 len = DBREG_DR7_LEN(d.dr[7], i); 586 if (len == DBREG_DR7_LEN_8) 587 len = 8; 588 else 589 len++; 590 db_printf(" %-5d %-8s %10s %3d ", 591 i, "enabled", watchtype_str(type), len); 592 db_printsym((db_addr_t)DBREG_DRX(&d, i), DB_STGY_ANY); 593 db_printf("\n"); 594 } else { 595 db_printf(" %-5d disabled\n", i); 596 } 597 } 598 599 db_printf("\ndebug register values:\n"); 600 for (i = 0; i < 8; i++) 601 if (i != 4 && i != 5) 602 db_printf(" dr%d 0x%016lx\n", i, DBREG_DRX(&d, i)); 603 db_printf("\n"); 604 } 605 606 void 607 amd64_db_resume_dbreg(void) 608 { 609 struct dbreg *d; 610 611 switch (PCPU_GET(dbreg_cmd)) { 612 case PC_DBREG_CMD_LOAD: 613 d = (struct dbreg *)PCPU_PTR(dbreg); 614 set_dbregs(NULL, d); 615 PCPU_SET(dbreg_cmd, PC_DBREG_CMD_NONE); 616 break; 617 } 618 }
Cache object: fcd87d91cf3fe15356907943f6c92a30
[ source navigation ] [ diff markup ] [ identifier search ] [ freetext search ] [ file search ] [ list types ] [ track identifier ]