1 /* 2 * CDDL HEADER START 3 * 4 * The contents of this file are subject to the terms of the 5 * Common Development and Distribution License, Version 1.0 only 6 * (the "License"). You may not use this file except in compliance 7 * with the License. 8 * 9 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 10 * or http://www.opensolaris.org/os/licensing. 11 * See the License for the specific language governing permissions 12 * and limitations under the License. 13 * 14 * When distributing Covered Code, include this CDDL HEADER in each 15 * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 16 * If applicable, add the following below this CDDL HEADER, with the 17 * fields enclosed by brackets "[]" replaced with your own identifying 18 * information: Portions Copyright [yyyy] [name of copyright owner] 19 * 20 * CDDL HEADER END 21 * 22 * $FreeBSD$ 23 */ 24 /* 25 * Copyright 2005 Sun Microsystems, Inc. All rights reserved. 26 * Use is subject to license terms. 27 */ 28 #include <sys/cdefs.h> 29 30 #include <sys/param.h> 31 #include <sys/systm.h> 32 #include <sys/kernel.h> 33 #include <sys/stack.h> 34 #include <sys/pcpu.h> 35 36 #include <machine/frame.h> 37 #include <machine/md_var.h> 38 #include <machine/reg.h> 39 #include <machine/stack.h> 40 41 #include <vm/vm.h> 42 #include <vm/vm_param.h> 43 #include <vm/pmap.h> 44 45 #include "regset.h" 46 47 uint8_t dtrace_fuword8_nocheck(void *); 48 uint16_t dtrace_fuword16_nocheck(void *); 49 uint32_t dtrace_fuword32_nocheck(void *); 50 uint64_t dtrace_fuword64_nocheck(void *); 51 52 int dtrace_ustackdepth_max = 2048; 53 54 void 55 dtrace_getpcstack(pc_t *pcstack, int pcstack_limit, int aframes, 56 uint32_t *intrpc) 57 { 58 int depth = 0; 59 register_t rbp; 60 struct amd64_frame *frame; 61 vm_offset_t callpc; 62 pc_t caller = (pc_t) solaris_cpu[curcpu].cpu_dtrace_caller; 63 64 if (intrpc != 0) 65 pcstack[depth++] = (pc_t) intrpc; 66 67 aframes++; 68 69 __asm __volatile("movq %%rbp,%0" : "=r" (rbp)); 70 71 frame = (struct amd64_frame *)rbp; 72 while (depth < pcstack_limit) { 73 if (!INKERNEL((long) frame)) 74 break; 75 76 callpc = frame->f_retaddr; 77 78 if (!INKERNEL(callpc)) 79 break; 80 81 if (aframes > 0) { 82 aframes--; 83 if ((aframes == 0) && (caller != 0)) { 84 pcstack[depth++] = caller; 85 } 86 } 87 else { 88 pcstack[depth++] = callpc; 89 } 90 91 if (frame->f_frame <= frame || 92 (vm_offset_t)frame->f_frame >= 93 (vm_offset_t)rbp + KSTACK_PAGES * PAGE_SIZE) 94 break; 95 frame = frame->f_frame; 96 } 97 98 for (; depth < pcstack_limit; depth++) { 99 pcstack[depth] = 0; 100 } 101 } 102 103 static int 104 dtrace_getustack_common(uint64_t *pcstack, int pcstack_limit, uintptr_t pc, 105 uintptr_t sp) 106 { 107 uintptr_t oldsp; 108 volatile uint16_t *flags = 109 (volatile uint16_t *)&cpu_core[curcpu].cpuc_dtrace_flags; 110 int ret = 0; 111 112 ASSERT(pcstack == NULL || pcstack_limit > 0); 113 ASSERT(dtrace_ustackdepth_max > 0); 114 115 while (pc != 0) { 116 /* 117 * We limit the number of times we can go around this 118 * loop to account for a circular stack. 119 */ 120 if (ret++ >= dtrace_ustackdepth_max) { 121 *flags |= CPU_DTRACE_BADSTACK; 122 cpu_core[curcpu].cpuc_dtrace_illval = sp; 123 break; 124 } 125 126 if (pcstack != NULL) { 127 *pcstack++ = (uint64_t)pc; 128 pcstack_limit--; 129 if (pcstack_limit <= 0) 130 break; 131 } 132 133 if (sp == 0) 134 break; 135 136 oldsp = sp; 137 138 pc = dtrace_fuword64((void *)(sp + 139 offsetof(struct amd64_frame, f_retaddr))); 140 sp = dtrace_fuword64((void *)sp); 141 142 if (sp == oldsp) { 143 *flags |= CPU_DTRACE_BADSTACK; 144 cpu_core[curcpu].cpuc_dtrace_illval = sp; 145 break; 146 } 147 148 /* 149 * This is totally bogus: if we faulted, we're going to clear 150 * the fault and break. This is to deal with the apparently 151 * broken Java stacks on x86. 152 */ 153 if (*flags & CPU_DTRACE_FAULT) { 154 *flags &= ~CPU_DTRACE_FAULT; 155 break; 156 } 157 } 158 159 return (ret); 160 } 161 162 void 163 dtrace_getupcstack(uint64_t *pcstack, int pcstack_limit) 164 { 165 proc_t *p = curproc; 166 struct trapframe *tf; 167 uintptr_t pc, sp, fp; 168 volatile uint16_t *flags = 169 (volatile uint16_t *)&cpu_core[curcpu].cpuc_dtrace_flags; 170 int n; 171 172 if (*flags & CPU_DTRACE_FAULT) 173 return; 174 175 if (pcstack_limit <= 0) 176 return; 177 178 /* 179 * If there's no user context we still need to zero the stack. 180 */ 181 if (p == NULL || (tf = curthread->td_frame) == NULL) 182 goto zero; 183 184 *pcstack++ = (uint64_t)p->p_pid; 185 pcstack_limit--; 186 187 if (pcstack_limit <= 0) 188 return; 189 190 pc = tf->tf_rip; 191 fp = tf->tf_rbp; 192 sp = tf->tf_rsp; 193 194 if (DTRACE_CPUFLAG_ISSET(CPU_DTRACE_ENTRY)) { 195 /* 196 * In an entry probe. The frame pointer has not yet been 197 * pushed (that happens in the function prologue). The 198 * best approach is to add the current pc as a missing top 199 * of stack and back the pc up to the caller, which is stored 200 * at the current stack pointer address since the call 201 * instruction puts it there right before the branch. 202 */ 203 204 *pcstack++ = (uint64_t)pc; 205 pcstack_limit--; 206 if (pcstack_limit <= 0) 207 return; 208 209 pc = dtrace_fuword64((void *) sp); 210 } 211 212 n = dtrace_getustack_common(pcstack, pcstack_limit, pc, fp); 213 ASSERT(n >= 0); 214 ASSERT(n <= pcstack_limit); 215 216 pcstack += n; 217 pcstack_limit -= n; 218 219 zero: 220 while (pcstack_limit-- > 0) 221 *pcstack++ = 0; 222 } 223 224 int 225 dtrace_getustackdepth(void) 226 { 227 proc_t *p = curproc; 228 struct trapframe *tf; 229 uintptr_t pc, fp, sp; 230 int n = 0; 231 232 if (p == NULL || (tf = curthread->td_frame) == NULL) 233 return (0); 234 235 if (DTRACE_CPUFLAG_ISSET(CPU_DTRACE_FAULT)) 236 return (-1); 237 238 pc = tf->tf_rip; 239 fp = tf->tf_rbp; 240 sp = tf->tf_rsp; 241 242 if (DTRACE_CPUFLAG_ISSET(CPU_DTRACE_ENTRY)) { 243 /* 244 * In an entry probe. The frame pointer has not yet been 245 * pushed (that happens in the function prologue). The 246 * best approach is to add the current pc as a missing top 247 * of stack and back the pc up to the caller, which is stored 248 * at the current stack pointer address since the call 249 * instruction puts it there right before the branch. 250 */ 251 252 pc = dtrace_fuword64((void *) sp); 253 n++; 254 } 255 256 n += dtrace_getustack_common(NULL, 0, pc, fp); 257 258 return (n); 259 } 260 261 void 262 dtrace_getufpstack(uint64_t *pcstack, uint64_t *fpstack, int pcstack_limit) 263 { 264 proc_t *p = curproc; 265 struct trapframe *tf; 266 uintptr_t pc, sp, fp; 267 volatile uint16_t *flags = 268 (volatile uint16_t *)&cpu_core[curcpu].cpuc_dtrace_flags; 269 #ifdef notyet /* XXX signal stack */ 270 uintptr_t oldcontext; 271 size_t s1, s2; 272 #endif 273 274 if (*flags & CPU_DTRACE_FAULT) 275 return; 276 277 if (pcstack_limit <= 0) 278 return; 279 280 /* 281 * If there's no user context we still need to zero the stack. 282 */ 283 if (p == NULL || (tf = curthread->td_frame) == NULL) 284 goto zero; 285 286 *pcstack++ = (uint64_t)p->p_pid; 287 pcstack_limit--; 288 289 if (pcstack_limit <= 0) 290 return; 291 292 pc = tf->tf_rip; 293 sp = tf->tf_rsp; 294 fp = tf->tf_rbp; 295 296 #ifdef notyet /* XXX signal stack */ 297 oldcontext = lwp->lwp_oldcontext; 298 s1 = sizeof (struct xframe) + 2 * sizeof (long); 299 s2 = s1 + sizeof (siginfo_t); 300 #endif 301 302 if (DTRACE_CPUFLAG_ISSET(CPU_DTRACE_ENTRY)) { 303 *pcstack++ = (uint64_t)pc; 304 *fpstack++ = 0; 305 pcstack_limit--; 306 if (pcstack_limit <= 0) 307 return; 308 309 pc = dtrace_fuword64((void *)sp); 310 } 311 312 while (pc != 0) { 313 *pcstack++ = (uint64_t)pc; 314 *fpstack++ = fp; 315 pcstack_limit--; 316 if (pcstack_limit <= 0) 317 break; 318 319 if (fp == 0) 320 break; 321 322 #ifdef notyet /* XXX signal stack */ 323 if (oldcontext == sp + s1 || oldcontext == sp + s2) { 324 ucontext_t *ucp = (ucontext_t *)oldcontext; 325 greg_t *gregs = ucp->uc_mcontext.gregs; 326 327 sp = dtrace_fulword(&gregs[REG_FP]); 328 pc = dtrace_fulword(&gregs[REG_PC]); 329 330 oldcontext = dtrace_fulword(&ucp->uc_link); 331 } else 332 #endif /* XXX */ 333 { 334 pc = dtrace_fuword64((void *)(fp + 335 offsetof(struct amd64_frame, f_retaddr))); 336 fp = dtrace_fuword64((void *)fp); 337 } 338 339 /* 340 * This is totally bogus: if we faulted, we're going to clear 341 * the fault and break. This is to deal with the apparently 342 * broken Java stacks on x86. 343 */ 344 if (*flags & CPU_DTRACE_FAULT) { 345 *flags &= ~CPU_DTRACE_FAULT; 346 break; 347 } 348 } 349 350 zero: 351 while (pcstack_limit-- > 0) 352 *pcstack++ = 0; 353 } 354 355 /*ARGSUSED*/ 356 uint64_t 357 dtrace_getarg(int arg, int aframes) 358 { 359 uintptr_t val; 360 struct amd64_frame *fp = (struct amd64_frame *)dtrace_getfp(); 361 uintptr_t *stack; 362 int i; 363 364 /* 365 * A total of 6 arguments are passed via registers; any argument with 366 * index of 5 or lower is therefore in a register. 367 */ 368 int inreg = 5; 369 370 for (i = 1; i <= aframes; i++) { 371 fp = fp->f_frame; 372 373 if (P2ROUNDUP(fp->f_retaddr, 16) == 374 (long)dtrace_invop_callsite) { 375 /* 376 * In the case of amd64, we will use the pointer to the 377 * regs structure that was pushed when we took the 378 * trap. To get this structure, we must increment 379 * beyond the frame structure, and then again beyond 380 * the calling RIP stored in dtrace_invop(). If the 381 * argument that we're seeking is passed on the stack, 382 * we'll pull the true stack pointer out of the saved 383 * registers and decrement our argument by the number 384 * of arguments passed in registers; if the argument 385 * we're seeking is passed in regsiters, we can just 386 * load it directly. 387 */ 388 struct trapframe *tf = 389 (struct trapframe *)((uintptr_t)&fp[1]); 390 391 if (arg <= inreg) { 392 switch (arg) { 393 case 0: 394 stack = (uintptr_t *)&tf->tf_rdi; 395 break; 396 case 1: 397 stack = (uintptr_t *)&tf->tf_rsi; 398 break; 399 case 2: 400 stack = (uintptr_t *)&tf->tf_rdx; 401 break; 402 case 3: 403 stack = (uintptr_t *)&tf->tf_rcx; 404 break; 405 case 4: 406 stack = (uintptr_t *)&tf->tf_r8; 407 break; 408 case 5: 409 stack = (uintptr_t *)&tf->tf_r9; 410 break; 411 } 412 arg = 0; 413 } else { 414 stack = (uintptr_t *)(tf->tf_rsp); 415 arg -= inreg; 416 } 417 goto load; 418 } 419 420 } 421 422 /* 423 * We know that we did not come through a trap to get into 424 * dtrace_probe() -- the provider simply called dtrace_probe() 425 * directly. As this is the case, we need to shift the argument 426 * that we're looking for: the probe ID is the first argument to 427 * dtrace_probe(), so the argument n will actually be found where 428 * one would expect to find argument (n + 1). 429 */ 430 arg++; 431 432 if (arg <= inreg) { 433 /* 434 * This shouldn't happen. If the argument is passed in a 435 * register then it should have been, well, passed in a 436 * register... 437 */ 438 DTRACE_CPUFLAG_SET(CPU_DTRACE_ILLOP); 439 return (0); 440 } 441 442 arg -= (inreg + 1); 443 stack = (uintptr_t *)fp + 2; 444 445 load: 446 DTRACE_CPUFLAG_SET(CPU_DTRACE_NOFAULT); 447 val = stack[arg]; 448 DTRACE_CPUFLAG_CLEAR(CPU_DTRACE_NOFAULT); 449 450 return (val); 451 return (0); 452 } 453 454 int 455 dtrace_getstackdepth(int aframes) 456 { 457 int depth = 0; 458 struct amd64_frame *frame; 459 vm_offset_t rbp; 460 461 aframes++; 462 rbp = dtrace_getfp(); 463 frame = (struct amd64_frame *)rbp; 464 depth++; 465 for(;;) { 466 if (!INKERNEL((long) frame)) 467 break; 468 if (!INKERNEL((long) frame->f_frame)) 469 break; 470 depth++; 471 if (frame->f_frame <= frame || 472 (vm_offset_t)frame->f_frame >= 473 (vm_offset_t)rbp + KSTACK_PAGES * PAGE_SIZE) 474 break; 475 frame = frame->f_frame; 476 } 477 if (depth < aframes) 478 return 0; 479 else 480 return depth - aframes; 481 } 482 483 ulong_t 484 dtrace_getreg(struct trapframe *rp, uint_t reg) 485 { 486 /* This table is dependent on reg.d. */ 487 int regmap[] = { 488 REG_GS, /* 0 GS */ 489 REG_FS, /* 1 FS */ 490 REG_ES, /* 2 ES */ 491 REG_DS, /* 3 DS */ 492 REG_RDI, /* 4 EDI */ 493 REG_RSI, /* 5 ESI */ 494 REG_RBP, /* 6 EBP, REG_FP */ 495 REG_RSP, /* 7 ESP */ 496 REG_RBX, /* 8 EBX, REG_R1 */ 497 REG_RDX, /* 9 EDX */ 498 REG_RCX, /* 10 ECX */ 499 REG_RAX, /* 11 EAX, REG_R0 */ 500 REG_TRAPNO, /* 12 TRAPNO */ 501 REG_ERR, /* 13 ERR */ 502 REG_RIP, /* 14 EIP, REG_PC */ 503 REG_CS, /* 15 CS */ 504 REG_RFL, /* 16 EFL, REG_PS */ 505 REG_RSP, /* 17 UESP, REG_SP */ 506 REG_SS /* 18 SS */ 507 }; 508 509 if (reg <= SS) { 510 if (reg >= sizeof (regmap) / sizeof (int)) { 511 DTRACE_CPUFLAG_SET(CPU_DTRACE_ILLOP); 512 return (0); 513 } 514 515 reg = regmap[reg]; 516 } else { 517 /* This is dependent on reg.d. */ 518 reg -= SS + 1; 519 } 520 521 switch (reg) { 522 case REG_RDI: 523 return (rp->tf_rdi); 524 case REG_RSI: 525 return (rp->tf_rsi); 526 case REG_RDX: 527 return (rp->tf_rdx); 528 case REG_RCX: 529 return (rp->tf_rcx); 530 case REG_R8: 531 return (rp->tf_r8); 532 case REG_R9: 533 return (rp->tf_r9); 534 case REG_RAX: 535 return (rp->tf_rax); 536 case REG_RBX: 537 return (rp->tf_rbx); 538 case REG_RBP: 539 return (rp->tf_rbp); 540 case REG_R10: 541 return (rp->tf_r10); 542 case REG_R11: 543 return (rp->tf_r11); 544 case REG_R12: 545 return (rp->tf_r12); 546 case REG_R13: 547 return (rp->tf_r13); 548 case REG_R14: 549 return (rp->tf_r14); 550 case REG_R15: 551 return (rp->tf_r15); 552 case REG_DS: 553 return (rp->tf_ds); 554 case REG_ES: 555 return (rp->tf_es); 556 case REG_FS: 557 return (rp->tf_fs); 558 case REG_GS: 559 return (rp->tf_gs); 560 case REG_TRAPNO: 561 return (rp->tf_trapno); 562 case REG_ERR: 563 return (rp->tf_err); 564 case REG_RIP: 565 return (rp->tf_rip); 566 case REG_CS: 567 return (rp->tf_cs); 568 case REG_SS: 569 return (rp->tf_ss); 570 case REG_RFL: 571 return (rp->tf_rflags); 572 case REG_RSP: 573 return (rp->tf_rsp); 574 default: 575 DTRACE_CPUFLAG_SET(CPU_DTRACE_ILLOP); 576 return (0); 577 } 578 } 579 580 static int 581 dtrace_copycheck(uintptr_t uaddr, uintptr_t kaddr, size_t size) 582 { 583 ASSERT(INKERNEL(kaddr) && kaddr + size >= kaddr); 584 585 if (uaddr + size > VM_MAXUSER_ADDRESS || uaddr + size < uaddr) { 586 DTRACE_CPUFLAG_SET(CPU_DTRACE_BADADDR); 587 cpu_core[curcpu].cpuc_dtrace_illval = uaddr; 588 return (0); 589 } 590 591 return (1); 592 } 593 594 void 595 dtrace_copyin(uintptr_t uaddr, uintptr_t kaddr, size_t size, 596 volatile uint16_t *flags) 597 { 598 if (dtrace_copycheck(uaddr, kaddr, size)) 599 dtrace_copy(uaddr, kaddr, size); 600 } 601 602 void 603 dtrace_copyout(uintptr_t kaddr, uintptr_t uaddr, size_t size, 604 volatile uint16_t *flags) 605 { 606 if (dtrace_copycheck(uaddr, kaddr, size)) 607 dtrace_copy(kaddr, uaddr, size); 608 } 609 610 void 611 dtrace_copyinstr(uintptr_t uaddr, uintptr_t kaddr, size_t size, 612 volatile uint16_t *flags) 613 { 614 if (dtrace_copycheck(uaddr, kaddr, size)) 615 dtrace_copystr(uaddr, kaddr, size, flags); 616 } 617 618 void 619 dtrace_copyoutstr(uintptr_t kaddr, uintptr_t uaddr, size_t size, 620 volatile uint16_t *flags) 621 { 622 if (dtrace_copycheck(uaddr, kaddr, size)) 623 dtrace_copystr(kaddr, uaddr, size, flags); 624 } 625 626 uint8_t 627 dtrace_fuword8(void *uaddr) 628 { 629 if ((uintptr_t)uaddr > VM_MAXUSER_ADDRESS) { 630 DTRACE_CPUFLAG_SET(CPU_DTRACE_BADADDR); 631 cpu_core[curcpu].cpuc_dtrace_illval = (uintptr_t)uaddr; 632 return (0); 633 } 634 return (dtrace_fuword8_nocheck(uaddr)); 635 } 636 637 uint16_t 638 dtrace_fuword16(void *uaddr) 639 { 640 if ((uintptr_t)uaddr > VM_MAXUSER_ADDRESS) { 641 DTRACE_CPUFLAG_SET(CPU_DTRACE_BADADDR); 642 cpu_core[curcpu].cpuc_dtrace_illval = (uintptr_t)uaddr; 643 return (0); 644 } 645 return (dtrace_fuword16_nocheck(uaddr)); 646 } 647 648 uint32_t 649 dtrace_fuword32(void *uaddr) 650 { 651 if ((uintptr_t)uaddr > VM_MAXUSER_ADDRESS) { 652 DTRACE_CPUFLAG_SET(CPU_DTRACE_BADADDR); 653 cpu_core[curcpu].cpuc_dtrace_illval = (uintptr_t)uaddr; 654 return (0); 655 } 656 return (dtrace_fuword32_nocheck(uaddr)); 657 } 658 659 uint64_t 660 dtrace_fuword64(void *uaddr) 661 { 662 if ((uintptr_t)uaddr > VM_MAXUSER_ADDRESS) { 663 DTRACE_CPUFLAG_SET(CPU_DTRACE_BADADDR); 664 cpu_core[curcpu].cpuc_dtrace_illval = (uintptr_t)uaddr; 665 return (0); 666 } 667 return (dtrace_fuword64_nocheck(uaddr)); 668 } 669