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 (the "License"). 6 * You may not use this file except in compliance with the License. 7 * 8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 9 * or http://www.opensolaris.org/os/licensing. 10 * See the License for the specific language governing permissions 11 * and limitations under the License. 12 * 13 * When distributing Covered Code, include this CDDL HEADER in each 14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 15 * If applicable, add the following below this CDDL HEADER, with the 16 * fields enclosed by brackets "[]" replaced with your own identifying 17 * information: Portions Copyright [yyyy] [name of copyright owner] 18 * 19 * CDDL HEADER END 20 */ 21 22 /* 23 * Copyright 2009 Sun Microsystems, Inc. All rights reserved. 24 * Use is subject to license terms. 25 */ 26 27 #include <sys/dtrace_impl.h> 28 #include <sys/atomic.h> 29 #include <sys/model.h> 30 #include <sys/frame.h> 31 #include <sys/stack.h> 32 #include <sys/machpcb.h> 33 #include <sys/procfs_isa.h> 34 #include <sys/cmn_err.h> 35 #include <sys/sysmacros.h> 36 37 #define DTRACE_FMT3OP3_MASK 0x81000000 38 #define DTRACE_FMT3OP3 0x80000000 39 #define DTRACE_FMT3RS1_SHIFT 14 40 #define DTRACE_FMT3RD_SHIFT 25 41 #define DTRACE_DISP22_SHIFT 10 42 #define DTRACE_RMASK 0x1f 43 #define DTRACE_REG_L0 16 44 #define DTRACE_REG_O7 15 45 #define DTRACE_REG_I0 24 46 #define DTRACE_REG_I6 30 47 #define DTRACE_RET 0x81c7e008 48 #define DTRACE_RETL 0x81c3e008 49 #define DTRACE_SAVE_MASK 0xc1f80000 50 #define DTRACE_SAVE 0x81e00000 51 #define DTRACE_RESTORE 0x81e80000 52 #define DTRACE_CALL_MASK 0xc0000000 53 #define DTRACE_CALL 0x40000000 54 #define DTRACE_JMPL_MASK 0x81f80000 55 #define DTRACE_JMPL 0x81c00000 56 #define DTRACE_BA_MASK 0xdfc00000 57 #define DTRACE_BA 0x10800000 58 #define DTRACE_BA_MAX 10 59 60 extern int dtrace_getupcstack_top(uint64_t *, int, uintptr_t *); 61 extern int dtrace_getustackdepth_top(uintptr_t *); 62 extern ulong_t dtrace_getreg_win(uint_t, uint_t); 63 extern void dtrace_putreg_win(uint_t, ulong_t); 64 extern int dtrace_fish(int, int, uintptr_t *); 65 66 int dtrace_ustackdepth_max = 2048; 67 68 /* 69 * This is similar in principle to getpcstack(), but there are several marked 70 * differences in implementation: 71 * 72 * (a) dtrace_getpcstack() is called from probe context. Thus, the call 73 * to flush_windows() from getpcstack() is a call to the probe-safe 74 * equivalent here. 75 * 76 * (b) dtrace_getpcstack() is willing to sacrifice some performance to get 77 * a correct stack. While consumers of getpcstack() are largely 78 * subsystem-specific in-kernel debugging facilities, DTrace consumers 79 * are arbitrary user-level analysis tools; dtrace_getpcstack() must 80 * deliver as correct a stack as possible. Details on the issues 81 * surrounding stack correctness are found below. 82 * 83 * (c) dtrace_getpcstack() _always_ fills in pcstack_limit pc_t's -- filling 84 * in the difference between the stack depth and pcstack_limit with NULLs. 85 * Due to this behavior dtrace_getpcstack() returns void. 86 * 87 * (d) dtrace_getpcstack() takes a third parameter, aframes, that 88 * denotes the number of _artificial frames_ on the bottom of the 89 * stack. An artificial frame is one induced by the provider; all 90 * artificial frames are stripped off before frames are stored to 91 * pcstack. 92 * 93 * (e) dtrace_getpcstack() takes a fourth parameter, pc, that indicates 94 * an interrupted program counter (if any). This should be a non-NULL 95 * value if and only if the hit probe is unanchored. (Anchored probes 96 * don't fire through an interrupt source.) This parameter is used to 97 * assure (b), above. 98 */ 99 void 100 dtrace_getpcstack(pc_t *pcstack, int pcstack_limit, int aframes, uint32_t *pc) 101 { 102 struct frame *fp, *nextfp, *minfp, *stacktop; 103 int depth = 0; 104 int on_intr, j = 0; 105 uint32_t i, r; 106 107 fp = (struct frame *)((caddr_t)dtrace_getfp() + STACK_BIAS); 108 dtrace_flush_windows(); 109 110 if (pc != NULL) { 111 /* 112 * If we've been passed a non-NULL pc, we need to determine 113 * whether or not the specified program counter falls in a leaf 114 * function. If it falls within a leaf function, we know that 115 * %o7 is valid in its frame (and we can just drive on). If 116 * it's a non-leaf, however, we know that %o7 is garbage in the 117 * bottom frame. To trim this frame, we simply increment 118 * aframes and drop into the stack-walking loop. 119 * 120 * To quickly determine if the specified program counter is in 121 * a leaf function, we exploit the fact that leaf functions 122 * tend to be short and non-leaf functions tend to frequently 123 * perform operations that are only permitted in a non-leaf 124 * function (e.g., using the %i's or %l's; calling a function; 125 * performing a restore). We exploit these tendencies by 126 * simply scanning forward from the specified %pc -- if we see 127 * an operation only permitted in a non-leaf, we know we're in 128 * a non-leaf; if we see a retl, we know we're in a leaf. 129 * Fortunately, one need not perform anywhere near full 130 * disassembly to effectively determine the former: determining 131 * that an instruction is a format-3 instruction and decoding 132 * its rd and rs1 fields, for example, requires very little 133 * manipulation. Overall, this method of leaf determination 134 * performs quite well: on average, we only examine between 135 * 1.5 and 2.5 instructions before making the determination. 136 * (Outliers do exist, however; of note is the non-leaf 137 * function ip_sioctl_not_ours() which -- as of this writing -- 138 * has a whopping 455 straight instructions that manipulate 139 * only %g's and %o's.) 140 */ 141 int delay = 0, branches = 0, taken = 0; 142 143 if (depth < pcstack_limit) 144 pcstack[depth++] = (pc_t)(uintptr_t)pc; 145 146 /* 147 * Our heuristic is exactly that -- a heuristic -- and there 148 * exists a possibility that we could be either be vectored 149 * off into the weeds (by following a bogus branch) or could 150 * wander off the end of the function and off the end of a 151 * text mapping (by not following a conditional branch at the 152 * end of the function that is effectively always taken). So 153 * as a precautionary measure, we set the NOFAULT flag. 154 */ 155 DTRACE_CPUFLAG_SET(CPU_DTRACE_NOFAULT); 156 157 for (;;) { 158 i = pc[j++]; 159 160 if ((i & DTRACE_FMT3OP3_MASK) == DTRACE_FMT3OP3) { 161 /* 162 * This is a format-3 instruction. We can 163 * look at rd and rs1. 164 */ 165 r = (i >> DTRACE_FMT3RS1_SHIFT) & DTRACE_RMASK; 166 167 if (r >= DTRACE_REG_L0) 168 goto nonleaf; 169 170 r = (i >> DTRACE_FMT3RD_SHIFT) & DTRACE_RMASK; 171 172 if (r >= DTRACE_REG_L0) 173 goto nonleaf; 174 175 if ((i & DTRACE_JMPL_MASK) == DTRACE_JMPL) { 176 delay = 1; 177 continue; 178 } 179 180 /* 181 * If we see explicit manipulation with %o7 182 * as a destination register, we know that 183 * %o7 is likely bogus -- and we treat this 184 * function as a non-leaf. 185 */ 186 if (r == DTRACE_REG_O7) { 187 if (delay) 188 goto leaf; 189 190 i &= DTRACE_JMPL_MASK; 191 192 if (i == DTRACE_JMPL) { 193 delay = 1; 194 continue; 195 } 196 197 goto nonleaf; 198 } 199 } else { 200 /* 201 * If this is a call, it may or may not be 202 * a leaf; we need to check the delay slot. 203 */ 204 if ((i & DTRACE_CALL_MASK) == DTRACE_CALL) { 205 delay = 1; 206 continue; 207 } 208 209 /* 210 * If we see a ret it's not a leaf; if we 211 * see a retl, it is a leaf. 212 */ 213 if (i == DTRACE_RET) 214 goto nonleaf; 215 216 if (i == DTRACE_RETL) 217 goto leaf; 218 219 /* 220 * If this is a ba (annulled or not), then we 221 * need to actually follow the branch. No, we 222 * don't look at the delay slot -- hopefully 223 * anything that can be gleaned from the delay 224 * slot can also be gleaned from the branch 225 * target. To prevent ourselves from iterating 226 * infinitely, we clamp the number of branches 227 * that we'll follow, and we refuse to follow 228 * the same branch twice consecutively. In 229 * both cases, we abort by deciding that we're 230 * looking at a leaf. While in theory this 231 * could be wrong (we could be in the middle of 232 * a loop in a non-leaf that ends with a ba and 233 * only manipulates outputs and globals in the 234 * body of the loop -- therefore leading us to 235 * the wrong conclusion), this doesn't seem to 236 * crop up in practice. (Or rather, this 237 * condition could not be deliberately induced, 238 * despite concerted effort.) 239 */ 240 if ((i & DTRACE_BA_MASK) == DTRACE_BA) { 241 if (++branches == DTRACE_BA_MAX || 242 taken == j) 243 goto nonleaf; 244 245 taken = j; 246 j += ((int)(i << DTRACE_DISP22_SHIFT) >> 247 DTRACE_DISP22_SHIFT) - 1; 248 continue; 249 } 250 251 /* 252 * Finally, if it's a save, it should be 253 * treated as a leaf; if it's a restore it 254 * should not be treated as a leaf. 255 */ 256 if ((i & DTRACE_SAVE_MASK) == DTRACE_SAVE) 257 goto leaf; 258 259 if ((i & DTRACE_SAVE_MASK) == DTRACE_RESTORE) 260 goto nonleaf; 261 } 262 263 if (delay) { 264 /* 265 * If this was a delay slot instruction and 266 * we didn't pick it up elsewhere, this is a 267 * non-leaf. 268 */ 269 goto nonleaf; 270 } 271 } 272 nonleaf: 273 aframes++; 274 leaf: 275 DTRACE_CPUFLAG_CLEAR(CPU_DTRACE_NOFAULT); 276 } 277 278 if ((on_intr = CPU_ON_INTR(CPU)) != 0) 279 stacktop = (struct frame *)(CPU->cpu_intr_stack + SA(MINFRAME)); 280 else 281 stacktop = (struct frame *)curthread->t_stk; 282 minfp = fp; 283 284 while (depth < pcstack_limit) { 285 nextfp = (struct frame *)((caddr_t)fp->fr_savfp + STACK_BIAS); 286 if (nextfp <= minfp || nextfp >= stacktop) { 287 if (!on_intr && nextfp == stacktop && aframes != 0) { 288 /* 289 * If we are exactly at the top of the stack 290 * with a non-zero number of artificial frames, 291 * it must be that the stack is filled with 292 * nothing _but_ artificial frames. In this 293 * case, we assert that this is so, zero 294 * pcstack, and return. 295 */ 296 ASSERT(aframes == 1); 297 ASSERT(depth == 0); 298 299 while (depth < pcstack_limit) 300 pcstack[depth++] = NULL; 301 return; 302 } 303 304 if (on_intr) { 305 /* 306 * Hop from interrupt stack to thread stack. 307 */ 308 stacktop = (struct frame *)curthread->t_stk; 309 minfp = (struct frame *)curthread->t_stkbase; 310 311 on_intr = 0; 312 313 if (nextfp > minfp && nextfp < stacktop) 314 continue; 315 } else { 316 /* 317 * High-level interrupts may occur when %sp is 318 * not necessarily contained in the stack 319 * bounds implied by %g7 -- interrupt thread 320 * management runs with %pil at DISP_LEVEL, 321 * and high-level interrupts may thus occur 322 * in windows when %sp and %g7 are not self- 323 * consistent. If we call dtrace_getpcstack() 324 * from a high-level interrupt that has occurred 325 * in such a window, we will fail the above test 326 * of nextfp against minfp/stacktop. If the 327 * high-level interrupt has in turn interrupted 328 * a non-passivated interrupt thread, we 329 * will execute the below code with non-zero 330 * aframes. We therefore want to assert that 331 * aframes is zero _or_ we are in a high-level 332 * interrupt -- but because cpu_intr_actv is 333 * updated with high-level interrupts enabled, 334 * we must reduce this to only asserting that 335 * %pil is greater than DISP_LEVEL. 336 */ 337 ASSERT(aframes == 0 || 338 dtrace_getipl() > DISP_LEVEL); 339 pcstack[depth++] = (pc_t)fp->fr_savpc; 340 } 341 342 while (depth < pcstack_limit) 343 pcstack[depth++] = NULL; 344 return; 345 } 346 347 if (aframes > 0) { 348 aframes--; 349 } else { 350 pcstack[depth++] = (pc_t)fp->fr_savpc; 351 } 352 353 fp = nextfp; 354 minfp = fp; 355 } 356 } 357 358 static int 359 dtrace_getustack_common(uint64_t *pcstack, int pcstack_limit, uintptr_t sp) 360 { 361 proc_t *p = curproc; 362 int ret = 0; 363 uintptr_t oldsp; 364 volatile uint16_t *flags = 365 (volatile uint16_t *)&cpu_core[CPU->cpu_id].cpuc_dtrace_flags; 366 367 ASSERT(pcstack == NULL || pcstack_limit > 0); 368 ASSERT(dtrace_ustackdepth_max > 0); 369 370 if (p->p_model == DATAMODEL_NATIVE) { 371 for (;;) { 372 struct frame *fr = (struct frame *)(sp + STACK_BIAS); 373 uintptr_t pc; 374 375 if (sp == 0 || fr == NULL || 376 !IS_P2ALIGNED((uintptr_t)fr, STACK_ALIGN)) 377 break; 378 379 oldsp = sp; 380 381 pc = dtrace_fulword(&fr->fr_savpc); 382 sp = dtrace_fulword(&fr->fr_savfp); 383 384 if (pc == 0) 385 break; 386 387 /* 388 * We limit the number of times we can go around this 389 * loop to account for a circular stack. 390 */ 391 if (sp == oldsp || ret++ >= dtrace_ustackdepth_max) { 392 *flags |= CPU_DTRACE_BADSTACK; 393 cpu_core[CPU->cpu_id].cpuc_dtrace_illval = sp; 394 break; 395 } 396 397 if (pcstack != NULL) { 398 *pcstack++ = pc; 399 pcstack_limit--; 400 if (pcstack_limit == 0) 401 break; 402 } 403 } 404 } else { 405 /* 406 * Truncate the stack pointer to 32-bits as there may be 407 * garbage in the upper bits which would normally be ignored 408 * by the processor in 32-bit mode. 409 */ 410 sp = (uint32_t)sp; 411 412 for (;;) { 413 struct frame32 *fr = (struct frame32 *)sp; 414 uint32_t pc; 415 416 if (sp == 0 || 417 !IS_P2ALIGNED((uintptr_t)fr, STACK_ALIGN32)) 418 break; 419 420 oldsp = sp; 421 422 pc = dtrace_fuword32(&fr->fr_savpc); 423 sp = dtrace_fuword32(&fr->fr_savfp); 424 425 if (pc == 0) 426 break; 427 428 if (sp == oldsp || ret++ >= dtrace_ustackdepth_max) { 429 *flags |= CPU_DTRACE_BADSTACK; 430 cpu_core[CPU->cpu_id].cpuc_dtrace_illval = sp; 431 break; 432 } 433 434 if (pcstack != NULL) { 435 *pcstack++ = pc; 436 pcstack_limit--; 437 if (pcstack_limit == 0) 438 break; 439 } 440 } 441 } 442 443 return (ret); 444 } 445 446 void 447 dtrace_getupcstack(uint64_t *pcstack, int pcstack_limit) 448 { 449 klwp_t *lwp = ttolwp(curthread); 450 proc_t *p = curproc; 451 struct regs *rp; 452 uintptr_t sp; 453 int n; 454 455 ASSERT(DTRACE_CPUFLAG_ISSET(CPU_DTRACE_NOFAULT)); 456 457 if (pcstack_limit <= 0) 458 return; 459 460 /* 461 * If there's no user context we still need to zero the stack. 462 */ 463 if (lwp == NULL || p == NULL || (rp = lwp->lwp_regs) == NULL) 464 goto zero; 465 466 *pcstack++ = (uint64_t)p->p_pid; 467 pcstack_limit--; 468 469 if (pcstack_limit <= 0) 470 return; 471 472 *pcstack++ = (uint64_t)rp->r_pc; 473 pcstack_limit--; 474 475 if (pcstack_limit <= 0) 476 return; 477 478 if (DTRACE_CPUFLAG_ISSET(CPU_DTRACE_ENTRY)) { 479 *pcstack++ = (uint64_t)rp->r_o7; 480 pcstack_limit--; 481 if (pcstack_limit <= 0) 482 return; 483 } 484 485 sp = rp->r_sp; 486 487 n = dtrace_getupcstack_top(pcstack, pcstack_limit, &sp); 488 ASSERT(n >= 0); 489 ASSERT(n <= pcstack_limit); 490 491 pcstack += n; 492 pcstack_limit -= n; 493 if (pcstack_limit <= 0) 494 return; 495 496 n = dtrace_getustack_common(pcstack, pcstack_limit, sp); 497 ASSERT(n >= 0); 498 ASSERT(n <= pcstack_limit); 499 500 pcstack += n; 501 pcstack_limit -= n; 502 503 zero: 504 while (pcstack_limit-- > 0) 505 *pcstack++ = NULL; 506 } 507 508 int 509 dtrace_getustackdepth(void) 510 { 511 klwp_t *lwp = ttolwp(curthread); 512 proc_t *p = curproc; 513 struct regs *rp; 514 uintptr_t sp; 515 int n = 1; 516 517 if (lwp == NULL || p == NULL || (rp = lwp->lwp_regs) == NULL) 518 return (0); 519 520 if (DTRACE_CPUFLAG_ISSET(CPU_DTRACE_FAULT)) 521 return (-1); 522 523 sp = rp->r_sp; 524 525 n += dtrace_getustackdepth_top(&sp); 526 n += dtrace_getustack_common(NULL, 0, sp); 527 528 /* 529 * Add one more to the stack depth if we're in an entry probe as long 530 * as the return address is non-NULL or there are additional frames 531 * beyond that NULL return address. 532 */ 533 if (DTRACE_CPUFLAG_ISSET(CPU_DTRACE_ENTRY) && 534 (rp->r_o7 != NULL || n != 1)) 535 n++; 536 537 return (n); 538 } 539 540 void 541 dtrace_getufpstack(uint64_t *pcstack, uint64_t *fpstack, int pcstack_limit) 542 { 543 klwp_t *lwp = ttolwp(curthread); 544 proc_t *p = ttoproc(curthread); 545 struct regs *rp; 546 uintptr_t sp; 547 548 if (pcstack_limit <= 0) 549 return; 550 551 /* 552 * If there's no user context we still need to zero the stack. 553 */ 554 if (lwp == NULL || p == NULL || (rp = lwp->lwp_regs) == NULL) 555 goto zero; 556 557 *pcstack++ = (uint64_t)p->p_pid; 558 pcstack_limit--; 559 560 if (pcstack_limit <= 0) 561 return; 562 563 if (DTRACE_CPUFLAG_ISSET(CPU_DTRACE_ENTRY)) { 564 *fpstack++ = 0; 565 *pcstack++ = (uint64_t)rp->r_pc; 566 pcstack_limit--; 567 if (pcstack_limit <= 0) 568 return; 569 570 *fpstack++ = (uint64_t)rp->r_sp; 571 *pcstack++ = (uint64_t)rp->r_o7; 572 pcstack_limit--; 573 } else { 574 *fpstack++ = (uint64_t)rp->r_sp; 575 *pcstack++ = (uint64_t)rp->r_pc; 576 pcstack_limit--; 577 } 578 579 if (pcstack_limit <= 0) 580 return; 581 582 sp = rp->r_sp; 583 584 dtrace_flush_user_windows(); 585 586 if (p->p_model == DATAMODEL_NATIVE) { 587 while (pcstack_limit > 0) { 588 struct frame *fr = (struct frame *)(sp + STACK_BIAS); 589 uintptr_t pc; 590 591 if (sp == 0 || fr == NULL || 592 ((uintptr_t)&fr->fr_savpc & 3) != 0 || 593 ((uintptr_t)&fr->fr_savfp & 3) != 0) 594 break; 595 596 pc = dtrace_fulword(&fr->fr_savpc); 597 sp = dtrace_fulword(&fr->fr_savfp); 598 599 if (pc == 0) 600 break; 601 602 *fpstack++ = sp; 603 *pcstack++ = pc; 604 pcstack_limit--; 605 } 606 } else { 607 /* 608 * Truncate the stack pointer to 32-bits as there may be 609 * garbage in the upper bits which would normally be ignored 610 * by the processor in 32-bit mode. 611 */ 612 sp = (uint32_t)sp; 613 614 while (pcstack_limit > 0) { 615 struct frame32 *fr = (struct frame32 *)sp; 616 uint32_t pc; 617 618 if (sp == 0 || 619 ((uintptr_t)&fr->fr_savpc & 3) != 0 || 620 ((uintptr_t)&fr->fr_savfp & 3) != 0) 621 break; 622 623 pc = dtrace_fuword32(&fr->fr_savpc); 624 sp = dtrace_fuword32(&fr->fr_savfp); 625 626 if (pc == 0) 627 break; 628 629 *fpstack++ = sp; 630 *pcstack++ = pc; 631 pcstack_limit--; 632 } 633 } 634 635 zero: 636 while (pcstack_limit-- > 0) 637 *pcstack++ = NULL; 638 } 639 640 uint64_t 641 dtrace_getarg(int arg, int aframes) 642 { 643 uintptr_t val; 644 struct frame *fp; 645 uint64_t rval; 646 647 /* 648 * Account for the fact that dtrace_getarg() consumes an additional 649 * stack frame. 650 */ 651 aframes++; 652 653 if (arg < 6) { 654 if (dtrace_fish(aframes, DTRACE_REG_I0 + arg, &val) == 0) 655 return (val); 656 } else { 657 if (dtrace_fish(aframes, DTRACE_REG_I6, &val) == 0) { 658 /* 659 * We have a stack pointer; grab the argument. 660 */ 661 fp = (struct frame *)(val + STACK_BIAS); 662 663 DTRACE_CPUFLAG_SET(CPU_DTRACE_NOFAULT); 664 rval = fp->fr_argx[arg - 6]; 665 DTRACE_CPUFLAG_CLEAR(CPU_DTRACE_NOFAULT); 666 667 return (rval); 668 } 669 } 670 671 /* 672 * There are other ways to do this. But the slow, painful way works 673 * just fine. Because this requires some loads, we need to set 674 * CPU_DTRACE_NOFAULT to protect against looking for an argument that 675 * isn't there. 676 */ 677 fp = (struct frame *)((caddr_t)dtrace_getfp() + STACK_BIAS); 678 dtrace_flush_windows(); 679 680 DTRACE_CPUFLAG_SET(CPU_DTRACE_NOFAULT); 681 682 for (aframes -= 1; aframes; aframes--) 683 fp = (struct frame *)((caddr_t)fp->fr_savfp + STACK_BIAS); 684 685 if (arg < 6) { 686 rval = fp->fr_arg[arg]; 687 } else { 688 fp = (struct frame *)((caddr_t)fp->fr_savfp + STACK_BIAS); 689 rval = fp->fr_argx[arg - 6]; 690 } 691 692 DTRACE_CPUFLAG_CLEAR(CPU_DTRACE_NOFAULT); 693 694 return (rval); 695 } 696 697 int 698 dtrace_getstackdepth(int aframes) 699 { 700 struct frame *fp, *nextfp, *minfp, *stacktop; 701 int depth = 0; 702 int on_intr; 703 704 fp = (struct frame *)((caddr_t)dtrace_getfp() + STACK_BIAS); 705 dtrace_flush_windows(); 706 707 if ((on_intr = CPU_ON_INTR(CPU)) != 0) 708 stacktop = (struct frame *)CPU->cpu_intr_stack + SA(MINFRAME); 709 else 710 stacktop = (struct frame *)curthread->t_stk; 711 minfp = fp; 712 713 for (;;) { 714 nextfp = (struct frame *)((caddr_t)fp->fr_savfp + STACK_BIAS); 715 if (nextfp <= minfp || nextfp >= stacktop) { 716 if (on_intr) { 717 /* 718 * Hop from interrupt stack to thread stack. 719 */ 720 stacktop = (struct frame *)curthread->t_stk; 721 minfp = (struct frame *)curthread->t_stkbase; 722 on_intr = 0; 723 continue; 724 } 725 726 return (++depth); 727 } 728 729 if (aframes > 0) { 730 aframes--; 731 } else { 732 depth++; 733 } 734 735 fp = nextfp; 736 minfp = fp; 737 } 738 } 739 740 /* 741 * This uses the same register numbering scheme as in sys/procfs_isa.h. 742 */ 743 ulong_t 744 dtrace_getreg(struct regs *rp, uint_t reg) 745 { 746 ulong_t value; 747 uintptr_t fp; 748 struct machpcb *mpcb; 749 750 if (reg == R_G0) 751 return (0); 752 753 if (reg <= R_G7) 754 return ((&rp->r_g1)[reg - 1]); 755 756 if (reg > R_I7) { 757 switch (reg) { 758 case R_CCR: 759 return ((rp->r_tstate >> TSTATE_CCR_SHIFT) & 760 TSTATE_CCR_MASK); 761 case R_PC: 762 return (rp->r_pc); 763 case R_nPC: 764 return (rp->r_npc); 765 case R_Y: 766 return (rp->r_y); 767 case R_ASI: 768 return ((rp->r_tstate >> TSTATE_ASI_SHIFT) & 769 TSTATE_ASI_MASK); 770 case R_FPRS: 771 return (dtrace_getfprs()); 772 default: 773 DTRACE_CPUFLAG_SET(CPU_DTRACE_ILLOP); 774 return (0); 775 } 776 } 777 778 /* 779 * We reach go to the fake restore case if the probe we hit was a pid 780 * return probe on a restore instruction. We partially emulate the 781 * restore in the kernel and then execute a simple restore 782 * instruction that we've secreted away to do the actual register 783 * window manipulation. We need to go one register window further 784 * down to get at the %ls, and %is and we need to treat %os like %is 785 * to pull them out of the topmost user frame. 786 */ 787 if (DTRACE_CPUFLAG_ISSET(CPU_DTRACE_FAKERESTORE)) { 788 if (reg > R_O7) 789 goto fake_restore; 790 else 791 reg += R_I0 - R_O0; 792 793 } else if (reg <= R_O7) { 794 return ((&rp->r_g1)[reg - 1]); 795 } 796 797 if (dtrace_getotherwin() > 0) 798 return (dtrace_getreg_win(reg, 1)); 799 800 mpcb = (struct machpcb *)((caddr_t)rp - REGOFF); 801 802 if (curproc->p_model == DATAMODEL_NATIVE) { 803 struct frame *fr = (void *)(rp->r_sp + STACK_BIAS); 804 805 if (mpcb->mpcb_wbcnt > 0) { 806 struct rwindow *rwin = (void *)mpcb->mpcb_wbuf; 807 int i = mpcb->mpcb_wbcnt; 808 do { 809 i--; 810 if ((long)mpcb->mpcb_spbuf[i] == rp->r_sp) 811 return (rwin[i].rw_local[reg - 16]); 812 } while (i > 0); 813 } 814 815 DTRACE_CPUFLAG_SET(CPU_DTRACE_NOFAULT); 816 value = dtrace_fulword(&fr->fr_local[reg - 16]); 817 DTRACE_CPUFLAG_CLEAR(CPU_DTRACE_NOFAULT); 818 } else { 819 struct frame32 *fr = (void *)(uintptr_t)(caddr32_t)rp->r_sp; 820 821 if (mpcb->mpcb_wbcnt > 0) { 822 struct rwindow32 *rwin = (void *)mpcb->mpcb_wbuf; 823 int i = mpcb->mpcb_wbcnt; 824 do { 825 i--; 826 if ((long)mpcb->mpcb_spbuf[i] == rp->r_sp) 827 return (rwin[i].rw_local[reg - 16]); 828 } while (i > 0); 829 } 830 831 DTRACE_CPUFLAG_SET(CPU_DTRACE_NOFAULT); 832 value = dtrace_fuword32(&fr->fr_local[reg - 16]); 833 DTRACE_CPUFLAG_CLEAR(CPU_DTRACE_NOFAULT); 834 } 835 836 return (value); 837 838 fake_restore: 839 ASSERT(R_L0 <= reg && reg <= R_I7); 840 841 /* 842 * We first look two user windows down to see if we can dig out 843 * the register we're looking for. 844 */ 845 if (dtrace_getotherwin() > 1) 846 return (dtrace_getreg_win(reg, 2)); 847 848 /* 849 * First we need to get the frame pointer and then we perform 850 * the same computation as in the non-fake-o-restore case. 851 */ 852 853 mpcb = (struct machpcb *)((caddr_t)rp - REGOFF); 854 855 if (dtrace_getotherwin() > 0) { 856 fp = dtrace_getreg_win(R_FP, 1); 857 goto got_fp; 858 } 859 860 if (curproc->p_model == DATAMODEL_NATIVE) { 861 struct frame *fr = (void *)(rp->r_sp + STACK_BIAS); 862 863 if (mpcb->mpcb_wbcnt > 0) { 864 struct rwindow *rwin = (void *)mpcb->mpcb_wbuf; 865 int i = mpcb->mpcb_wbcnt; 866 do { 867 i--; 868 if ((long)mpcb->mpcb_spbuf[i] == rp->r_sp) { 869 fp = rwin[i].rw_fp; 870 goto got_fp; 871 } 872 } while (i > 0); 873 } 874 875 DTRACE_CPUFLAG_SET(CPU_DTRACE_NOFAULT); 876 fp = dtrace_fulword(&fr->fr_savfp); 877 DTRACE_CPUFLAG_CLEAR(CPU_DTRACE_NOFAULT); 878 if (cpu_core[CPU->cpu_id].cpuc_dtrace_flags & CPU_DTRACE_FAULT) 879 return (0); 880 } else { 881 struct frame32 *fr = (void *)(uintptr_t)(caddr32_t)rp->r_sp; 882 883 if (mpcb->mpcb_wbcnt > 0) { 884 struct rwindow32 *rwin = (void *)mpcb->mpcb_wbuf; 885 int i = mpcb->mpcb_wbcnt; 886 do { 887 i--; 888 if ((long)mpcb->mpcb_spbuf[i] == rp->r_sp) { 889 fp = rwin[i].rw_fp; 890 goto got_fp; 891 } 892 } while (i > 0); 893 } 894 895 DTRACE_CPUFLAG_SET(CPU_DTRACE_NOFAULT); 896 fp = dtrace_fuword32(&fr->fr_savfp); 897 DTRACE_CPUFLAG_CLEAR(CPU_DTRACE_NOFAULT); 898 if (cpu_core[CPU->cpu_id].cpuc_dtrace_flags & CPU_DTRACE_FAULT) 899 return (0); 900 } 901 got_fp: 902 903 if (curproc->p_model == DATAMODEL_NATIVE) { 904 struct frame *fr = (void *)(fp + STACK_BIAS); 905 906 if (mpcb->mpcb_wbcnt > 0) { 907 struct rwindow *rwin = (void *)mpcb->mpcb_wbuf; 908 int i = mpcb->mpcb_wbcnt; 909 do { 910 i--; 911 if ((long)mpcb->mpcb_spbuf[i] == fp) 912 return (rwin[i].rw_local[reg - 16]); 913 } while (i > 0); 914 } 915 916 DTRACE_CPUFLAG_SET(CPU_DTRACE_NOFAULT); 917 value = dtrace_fulword(&fr->fr_local[reg - 16]); 918 DTRACE_CPUFLAG_CLEAR(CPU_DTRACE_NOFAULT); 919 } else { 920 struct frame32 *fr = (void *)(uintptr_t)(caddr32_t)fp; 921 922 if (mpcb->mpcb_wbcnt > 0) { 923 struct rwindow32 *rwin = (void *)mpcb->mpcb_wbuf; 924 int i = mpcb->mpcb_wbcnt; 925 do { 926 i--; 927 if ((long)mpcb->mpcb_spbuf[i] == fp) 928 return (rwin[i].rw_local[reg - 16]); 929 } while (i > 0); 930 } 931 932 DTRACE_CPUFLAG_SET(CPU_DTRACE_NOFAULT); 933 value = dtrace_fuword32(&fr->fr_local[reg - 16]); 934 DTRACE_CPUFLAG_CLEAR(CPU_DTRACE_NOFAULT); 935 } 936 937 return (value); 938 } 939