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 /* 23 * Copyright 2005 Sun Microsystems, Inc. All rights reserved. 24 * Use is subject to license terms. 25 */ 26 27 #pragma ident "%Z%%M% %I% %E% SMI" 28 29 #include <sys/dtrace_impl.h> 30 #include <sys/atomic.h> 31 #include <sys/model.h> 32 #include <sys/frame.h> 33 #include <sys/stack.h> 34 #include <sys/machpcb.h> 35 #include <sys/procfs_isa.h> 36 #include <sys/cmn_err.h> 37 #include <sys/sysmacros.h> 38 39 #define DTRACE_FMT3OP3_MASK 0x81000000 40 #define DTRACE_FMT3OP3 0x80000000 41 #define DTRACE_FMT3RS1_SHIFT 14 42 #define DTRACE_FMT3RD_SHIFT 25 43 #define DTRACE_DISP22_SHIFT 10 44 #define DTRACE_RMASK 0x1f 45 #define DTRACE_REG_L0 16 46 #define DTRACE_REG_O7 15 47 #define DTRACE_REG_I0 24 48 #define DTRACE_REG_I6 30 49 #define DTRACE_RET 0x81c7e008 50 #define DTRACE_RETL 0x81c3e008 51 #define DTRACE_SAVE_MASK 0xc1f80000 52 #define DTRACE_SAVE 0x81e00000 53 #define DTRACE_RESTORE 0x81e80000 54 #define DTRACE_CALL_MASK 0xc0000000 55 #define DTRACE_CALL 0x40000000 56 #define DTRACE_JMPL_MASK 0x81f10000 57 #define DTRACE_JMPL 0x81c00000 58 #define DTRACE_BA_MASK 0xdfc00000 59 #define DTRACE_BA 0x10800000 60 #define DTRACE_BA_MAX 10 61 62 extern int dtrace_getupcstack_top(uint64_t *, int, uintptr_t *); 63 extern int dtrace_getustackdepth_top(uintptr_t *); 64 extern ulong_t dtrace_getreg_win(uint_t, uint_t); 65 extern void dtrace_putreg_win(uint_t, ulong_t); 66 extern int dtrace_fish(int, int, uintptr_t *); 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)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; 363 364 ASSERT(pcstack == NULL || pcstack_limit > 0); 365 366 if (p->p_model == DATAMODEL_NATIVE) { 367 for (;;) { 368 struct frame *fr = (struct frame *)(sp + STACK_BIAS); 369 uintptr_t pc; 370 371 if (sp == 0 || fr == NULL || 372 !IS_P2ALIGNED((uintptr_t)fr, STACK_ALIGN)) 373 break; 374 375 pc = dtrace_fulword(&fr->fr_savpc); 376 sp = dtrace_fulword(&fr->fr_savfp); 377 378 if (pc == 0) 379 break; 380 381 ret++; 382 383 if (pcstack != NULL) { 384 *pcstack++ = pc; 385 pcstack_limit--; 386 if (pcstack_limit == 0) 387 break; 388 } 389 } 390 } else { 391 for (;;) { 392 struct frame32 *fr = (struct frame32 *)sp; 393 uint32_t pc; 394 395 if (sp == 0 || 396 !IS_P2ALIGNED((uintptr_t)fr, STACK_ALIGN32)) 397 break; 398 399 pc = dtrace_fuword32(&fr->fr_savpc); 400 sp = dtrace_fuword32(&fr->fr_savfp); 401 402 if (pc == 0) 403 break; 404 405 ret++; 406 407 if (pcstack != NULL) { 408 *pcstack++ = pc; 409 pcstack_limit--; 410 if (pcstack_limit == 0) 411 break; 412 } 413 } 414 } 415 416 return (ret); 417 } 418 419 void 420 dtrace_getupcstack(uint64_t *pcstack, int pcstack_limit) 421 { 422 klwp_t *lwp = ttolwp(curthread); 423 proc_t *p = curproc; 424 struct regs *rp; 425 uintptr_t sp; 426 int n; 427 428 if (lwp == NULL || p == NULL || (rp = lwp->lwp_regs) == NULL) 429 return; 430 431 if (pcstack_limit <= 0) 432 return; 433 434 *pcstack++ = (uint64_t)p->p_pid; 435 pcstack_limit--; 436 437 if (pcstack_limit <= 0) 438 return; 439 440 *pcstack++ = (uint64_t)rp->r_pc; 441 pcstack_limit--; 442 443 if (pcstack_limit <= 0) 444 return; 445 446 if (DTRACE_CPUFLAG_ISSET(CPU_DTRACE_ENTRY)) { 447 *pcstack++ = (uint64_t)rp->r_o7; 448 pcstack_limit--; 449 if (pcstack_limit <= 0) 450 return; 451 } 452 453 sp = rp->r_sp; 454 455 n = dtrace_getupcstack_top(pcstack, pcstack_limit, &sp); 456 ASSERT(n >= 0); 457 ASSERT(n <= pcstack_limit); 458 459 pcstack += n; 460 pcstack_limit -= n; 461 if (pcstack_limit <= 0) 462 return; 463 464 n = dtrace_getustack_common(pcstack, pcstack_limit, sp); 465 ASSERT(n >= 0); 466 ASSERT(n <= pcstack_limit); 467 468 pcstack += n; 469 pcstack_limit -= n; 470 471 while (pcstack_limit-- > 0) 472 *pcstack++ = NULL; 473 } 474 475 int 476 dtrace_getustackdepth(void) 477 { 478 klwp_t *lwp = ttolwp(curthread); 479 proc_t *p = curproc; 480 struct regs *rp; 481 uintptr_t sp; 482 int n = 1; 483 484 if (lwp == NULL || p == NULL || (rp = lwp->lwp_regs) == NULL) 485 return (0); 486 487 if (DTRACE_CPUFLAG_ISSET(CPU_DTRACE_FAULT)) 488 return (-1); 489 490 if (DTRACE_CPUFLAG_ISSET(CPU_DTRACE_ENTRY)) 491 n++; 492 493 sp = rp->r_sp; 494 495 n += dtrace_getustackdepth_top(&sp); 496 n += dtrace_getustack_common(NULL, 0, sp); 497 498 return (n); 499 } 500 501 void 502 dtrace_getufpstack(uint64_t *pcstack, uint64_t *fpstack, int pcstack_limit) 503 { 504 klwp_t *lwp = ttolwp(curthread); 505 proc_t *p = ttoproc(curthread); 506 struct regs *rp; 507 uintptr_t sp; 508 509 if (lwp == NULL || p == NULL || (rp = lwp->lwp_regs) == NULL) 510 return; 511 512 if (pcstack_limit <= 0) 513 return; 514 515 *pcstack++ = (uint64_t)p->p_pid; 516 pcstack_limit--; 517 518 if (pcstack_limit <= 0) 519 return; 520 521 if (DTRACE_CPUFLAG_ISSET(CPU_DTRACE_ENTRY)) { 522 *fpstack++ = 0; 523 *pcstack++ = (uint64_t)rp->r_pc; 524 pcstack_limit--; 525 if (pcstack_limit <= 0) 526 return; 527 528 *fpstack++ = (uint64_t)rp->r_sp; 529 *pcstack++ = (uint64_t)rp->r_o7; 530 pcstack_limit--; 531 } else { 532 *fpstack++ = (uint64_t)rp->r_sp; 533 *pcstack++ = (uint64_t)rp->r_pc; 534 pcstack_limit--; 535 } 536 537 if (pcstack_limit <= 0) 538 return; 539 540 sp = rp->r_sp; 541 542 dtrace_flush_user_windows(); 543 544 if (p->p_model == DATAMODEL_NATIVE) { 545 while (pcstack_limit > 0) { 546 struct frame *fr = (struct frame *)(sp + STACK_BIAS); 547 uintptr_t pc; 548 549 if (sp == 0 || fr == NULL || 550 ((uintptr_t)&fr->fr_savpc & 3) != 0 || 551 ((uintptr_t)&fr->fr_savfp & 3) != 0) 552 break; 553 554 pc = dtrace_fulword(&fr->fr_savpc); 555 sp = dtrace_fulword(&fr->fr_savfp); 556 557 if (pc == 0) 558 break; 559 560 *fpstack++ = sp; 561 *pcstack++ = pc; 562 pcstack_limit--; 563 } 564 } else { 565 while (pcstack_limit > 0) { 566 struct frame32 *fr = (struct frame32 *)sp; 567 uint32_t pc; 568 569 if (sp == 0 || 570 ((uintptr_t)&fr->fr_savpc & 3) != 0 || 571 ((uintptr_t)&fr->fr_savfp & 3) != 0) 572 break; 573 574 pc = dtrace_fuword32(&fr->fr_savpc); 575 sp = dtrace_fuword32(&fr->fr_savfp); 576 577 if (pc == 0) 578 break; 579 580 *fpstack++ = sp; 581 *pcstack++ = pc; 582 pcstack_limit--; 583 } 584 } 585 586 while (pcstack_limit-- > 0) 587 *pcstack++ = NULL; 588 } 589 590 uint64_t 591 dtrace_getarg(int arg, int aframes) 592 { 593 uintptr_t val; 594 struct frame *fp; 595 uint64_t rval; 596 597 /* 598 * Account for the fact that dtrace_getarg() consumes an additional 599 * stack frame. 600 */ 601 aframes++; 602 603 if (arg < 6) { 604 if (dtrace_fish(aframes, DTRACE_REG_I0 + arg, &val) == 0) 605 return (val); 606 } else { 607 if (dtrace_fish(aframes, DTRACE_REG_I6, &val) == 0) { 608 /* 609 * We have a stack pointer; grab the argument. 610 */ 611 fp = (struct frame *)(val + STACK_BIAS); 612 613 DTRACE_CPUFLAG_SET(CPU_DTRACE_NOFAULT); 614 rval = fp->fr_argx[arg - 6]; 615 DTRACE_CPUFLAG_CLEAR(CPU_DTRACE_NOFAULT); 616 617 return (rval); 618 } 619 } 620 621 /* 622 * There are other ways to do this. But the slow, painful way works 623 * just fine. Because this requires some loads, we need to set 624 * CPU_DTRACE_NOFAULT to protect against looking for an argument that 625 * isn't there. 626 */ 627 fp = (struct frame *)((caddr_t)dtrace_getfp() + STACK_BIAS); 628 dtrace_flush_windows(); 629 630 DTRACE_CPUFLAG_SET(CPU_DTRACE_NOFAULT); 631 632 for (aframes -= 1; aframes; aframes--) 633 fp = (struct frame *)((caddr_t)fp->fr_savfp + STACK_BIAS); 634 635 if (arg < 6) { 636 rval = fp->fr_arg[arg]; 637 } else { 638 fp = (struct frame *)((caddr_t)fp->fr_savfp + STACK_BIAS); 639 rval = fp->fr_argx[arg - 6]; 640 } 641 642 DTRACE_CPUFLAG_CLEAR(CPU_DTRACE_NOFAULT); 643 644 return (rval); 645 } 646 647 int 648 dtrace_getstackdepth(int aframes) 649 { 650 struct frame *fp, *nextfp, *minfp, *stacktop; 651 int depth = 0; 652 int on_intr; 653 654 fp = (struct frame *)((caddr_t)dtrace_getfp() + STACK_BIAS); 655 dtrace_flush_windows(); 656 657 if ((on_intr = CPU_ON_INTR(CPU)) != 0) 658 stacktop = (struct frame *)CPU->cpu_intr_stack + SA(MINFRAME); 659 else 660 stacktop = (struct frame *)curthread->t_stk; 661 minfp = fp; 662 663 for (;;) { 664 nextfp = (struct frame *)((caddr_t)fp->fr_savfp + STACK_BIAS); 665 if (nextfp <= minfp || nextfp >= stacktop) { 666 if (on_intr) { 667 /* 668 * Hop from interrupt stack to thread stack. 669 */ 670 stacktop = (struct frame *)curthread->t_stk; 671 minfp = (struct frame *)curthread->t_stkbase; 672 on_intr = 0; 673 continue; 674 } 675 676 return (++depth); 677 } 678 679 if (aframes > 0) { 680 aframes--; 681 } else { 682 depth++; 683 } 684 685 fp = nextfp; 686 minfp = fp; 687 } 688 } 689 690 /* 691 * This uses the same register numbering scheme as in sys/procfs_isa.h. 692 */ 693 ulong_t 694 dtrace_getreg(struct regs *rp, uint_t reg) 695 { 696 ulong_t value; 697 uintptr_t fp; 698 struct machpcb *mpcb; 699 700 if (reg == R_G0) 701 return (0); 702 703 if (reg <= R_G7) 704 return ((&rp->r_g1)[reg - 1]); 705 706 if (reg > R_I7) { 707 switch (reg) { 708 case R_CCR: 709 return ((rp->r_tstate >> TSTATE_CCR_SHIFT) & 710 TSTATE_CCR_MASK); 711 case R_PC: 712 return (rp->r_pc); 713 case R_nPC: 714 return (rp->r_npc); 715 case R_Y: 716 return (rp->r_y); 717 case R_ASI: 718 return ((rp->r_tstate >> TSTATE_ASI_SHIFT) & 719 TSTATE_ASI_MASK); 720 case R_FPRS: 721 return (dtrace_getfprs()); 722 default: 723 DTRACE_CPUFLAG_SET(CPU_DTRACE_ILLOP); 724 return (0); 725 } 726 } 727 728 /* 729 * We reach go to the fake restore case if the probe we hit was a pid 730 * return probe on a restore instruction. We partially emulate the 731 * restore in the kernel and then execute a simple restore 732 * instruction that we've secreted away to do the actual register 733 * window manipulation. We need to go one register window further 734 * down to get at the %ls, and %is and we need to treat %os like %is 735 * to pull them out of the topmost user frame. 736 */ 737 if (DTRACE_CPUFLAG_ISSET(CPU_DTRACE_FAKERESTORE)) { 738 if (reg > R_O7) 739 goto fake_restore; 740 else 741 reg += R_I0 - R_O0; 742 743 } else if (reg <= R_O7) { 744 return ((&rp->r_g1)[reg - 1]); 745 } 746 747 if (dtrace_getotherwin() > 0) 748 return (dtrace_getreg_win(reg, 1)); 749 750 mpcb = (struct machpcb *)((caddr_t)rp - REGOFF); 751 752 if (curproc->p_model == DATAMODEL_NATIVE) { 753 struct frame *fr = (void *)(rp->r_sp + STACK_BIAS); 754 755 if (mpcb->mpcb_wbcnt > 0) { 756 struct rwindow *rwin = (void *)mpcb->mpcb_wbuf; 757 int i = mpcb->mpcb_wbcnt; 758 do { 759 i--; 760 if ((long)mpcb->mpcb_spbuf[i] == rp->r_sp) 761 return (rwin[i].rw_local[reg - 16]); 762 } while (i > 0); 763 } 764 765 DTRACE_CPUFLAG_SET(CPU_DTRACE_NOFAULT); 766 value = dtrace_fulword(&fr->fr_local[reg - 16]); 767 DTRACE_CPUFLAG_CLEAR(CPU_DTRACE_NOFAULT); 768 } else { 769 struct frame32 *fr = (void *)(caddr32_t)rp->r_sp; 770 771 if (mpcb->mpcb_wbcnt > 0) { 772 struct rwindow32 *rwin = (void *)mpcb->mpcb_wbuf; 773 int i = mpcb->mpcb_wbcnt; 774 do { 775 i--; 776 if ((long)mpcb->mpcb_spbuf[i] == rp->r_sp) 777 return (rwin[i].rw_local[reg - 16]); 778 } while (i > 0); 779 } 780 781 DTRACE_CPUFLAG_SET(CPU_DTRACE_NOFAULT); 782 value = dtrace_fuword32(&fr->fr_local[reg - 16]); 783 DTRACE_CPUFLAG_CLEAR(CPU_DTRACE_NOFAULT); 784 } 785 786 return (value); 787 788 fake_restore: 789 ASSERT(R_L0 <= reg && reg <= R_I7); 790 791 /* 792 * We first look two user windows down to see if we can dig out 793 * the register we're looking for. 794 */ 795 if (dtrace_getotherwin() > 1) 796 return (dtrace_getreg_win(reg, 2)); 797 798 /* 799 * First we need to get the frame pointer and then we perform 800 * the same computation as in the non-fake-o-restore case. 801 */ 802 803 mpcb = (struct machpcb *)((caddr_t)rp - REGOFF); 804 805 if (dtrace_getotherwin() > 0) { 806 fp = dtrace_getreg_win(R_FP, 1); 807 goto got_fp; 808 } 809 810 if (curproc->p_model == DATAMODEL_NATIVE) { 811 struct frame *fr = (void *)(rp->r_sp + STACK_BIAS); 812 813 if (mpcb->mpcb_wbcnt > 0) { 814 struct rwindow *rwin = (void *)mpcb->mpcb_wbuf; 815 int i = mpcb->mpcb_wbcnt; 816 do { 817 i--; 818 if ((long)mpcb->mpcb_spbuf[i] == rp->r_sp) { 819 fp = rwin[i].rw_fp; 820 goto got_fp; 821 } 822 } while (i > 0); 823 } 824 825 DTRACE_CPUFLAG_SET(CPU_DTRACE_NOFAULT); 826 fp = dtrace_fulword(&fr->fr_savfp); 827 DTRACE_CPUFLAG_CLEAR(CPU_DTRACE_NOFAULT); 828 if (cpu_core[CPU->cpu_id].cpuc_dtrace_flags & CPU_DTRACE_FAULT) 829 return (0); 830 } else { 831 struct frame32 *fr = (void *)(caddr32_t)rp->r_sp; 832 833 if (mpcb->mpcb_wbcnt > 0) { 834 struct rwindow32 *rwin = (void *)mpcb->mpcb_wbuf; 835 int i = mpcb->mpcb_wbcnt; 836 do { 837 i--; 838 if ((long)mpcb->mpcb_spbuf[i] == rp->r_sp) { 839 fp = rwin[i].rw_fp; 840 goto got_fp; 841 } 842 } while (i > 0); 843 } 844 845 DTRACE_CPUFLAG_SET(CPU_DTRACE_NOFAULT); 846 fp = dtrace_fuword32(&fr->fr_savfp); 847 DTRACE_CPUFLAG_CLEAR(CPU_DTRACE_NOFAULT); 848 if (cpu_core[CPU->cpu_id].cpuc_dtrace_flags & CPU_DTRACE_FAULT) 849 return (0); 850 } 851 got_fp: 852 853 if (curproc->p_model == DATAMODEL_NATIVE) { 854 struct frame *fr = (void *)(fp + STACK_BIAS); 855 856 if (mpcb->mpcb_wbcnt > 0) { 857 struct rwindow *rwin = (void *)mpcb->mpcb_wbuf; 858 int i = mpcb->mpcb_wbcnt; 859 do { 860 i--; 861 if ((long)mpcb->mpcb_spbuf[i] == fp) 862 return (rwin[i].rw_local[reg - 16]); 863 } while (i > 0); 864 } 865 866 DTRACE_CPUFLAG_SET(CPU_DTRACE_NOFAULT); 867 value = dtrace_fulword(&fr->fr_local[reg - 16]); 868 DTRACE_CPUFLAG_CLEAR(CPU_DTRACE_NOFAULT); 869 } else { 870 struct frame32 *fr = (void *)(caddr32_t)fp; 871 872 if (mpcb->mpcb_wbcnt > 0) { 873 struct rwindow32 *rwin = (void *)mpcb->mpcb_wbuf; 874 int i = mpcb->mpcb_wbcnt; 875 do { 876 i--; 877 if ((long)mpcb->mpcb_spbuf[i] == fp) 878 return (rwin[i].rw_local[reg - 16]); 879 } while (i > 0); 880 } 881 882 DTRACE_CPUFLAG_SET(CPU_DTRACE_NOFAULT); 883 value = dtrace_fuword32(&fr->fr_local[reg - 16]); 884 DTRACE_CPUFLAG_CLEAR(CPU_DTRACE_NOFAULT); 885 } 886 887 return (value); 888 } 889