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 /* 24 * Copyright 2005 Sun Microsystems, Inc. All rights reserved. 25 * Use is subject to license terms. 26 */ 27 28 #pragma ident "%Z%%M% %I% %E% SMI" 29 30 #include <sys/dtrace_impl.h> 31 #include <sys/atomic.h> 32 #include <sys/model.h> 33 #include <sys/frame.h> 34 #include <sys/stack.h> 35 #include <sys/machpcb.h> 36 #include <sys/procfs_isa.h> 37 #include <sys/cmn_err.h> 38 #include <sys/sysmacros.h> 39 40 #define DTRACE_FMT3OP3_MASK 0x81000000 41 #define DTRACE_FMT3OP3 0x80000000 42 #define DTRACE_FMT3RS1_SHIFT 14 43 #define DTRACE_FMT3RD_SHIFT 25 44 #define DTRACE_DISP22_SHIFT 10 45 #define DTRACE_RMASK 0x1f 46 #define DTRACE_REG_L0 16 47 #define DTRACE_REG_O7 15 48 #define DTRACE_REG_I0 24 49 #define DTRACE_REG_I6 30 50 #define DTRACE_RET 0x81c7e008 51 #define DTRACE_RETL 0x81c3e008 52 #define DTRACE_SAVE_MASK 0xc1f80000 53 #define DTRACE_SAVE 0x81e00000 54 #define DTRACE_RESTORE 0x81e80000 55 #define DTRACE_CALL_MASK 0xc0000000 56 #define DTRACE_CALL 0x40000000 57 #define DTRACE_JMPL_MASK 0x81f10000 58 #define DTRACE_JMPL 0x81c00000 59 #define DTRACE_BA_MASK 0xdfc00000 60 #define DTRACE_BA 0x10800000 61 #define DTRACE_BA_MAX 10 62 63 extern int dtrace_getupcstack_top(uint64_t *, int, uintptr_t *); 64 extern int dtrace_getustackdepth_top(uintptr_t *); 65 extern ulong_t dtrace_getreg_win(uint_t, uint_t); 66 extern void dtrace_putreg_win(uint_t, ulong_t); 67 extern int dtrace_fish(int, int, uintptr_t *); 68 69 /* 70 * This is similar in principle to getpcstack(), but there are several marked 71 * differences in implementation: 72 * 73 * (a) dtrace_getpcstack() is called from probe context. Thus, the call 74 * to flush_windows() from getpcstack() is a call to the probe-safe 75 * equivalent here. 76 * 77 * (b) dtrace_getpcstack() is willing to sacrifice some performance to get 78 * a correct stack. While consumers of getpcstack() are largely 79 * subsystem-specific in-kernel debugging facilities, DTrace consumers 80 * are arbitrary user-level analysis tools; dtrace_getpcstack() must 81 * deliver as correct a stack as possible. Details on the issues 82 * surrounding stack correctness are found below. 83 * 84 * (c) dtrace_getpcstack() _always_ fills in pcstack_limit pc_t's -- filling 85 * in the difference between the stack depth and pcstack_limit with NULLs. 86 * Due to this behavior dtrace_getpcstack() returns void. 87 * 88 * (d) dtrace_getpcstack() takes a third parameter, aframes, that 89 * denotes the number of _artificial frames_ on the bottom of the 90 * stack. An artificial frame is one induced by the provider; all 91 * artificial frames are stripped off before frames are stored to 92 * pcstack. 93 * 94 * (e) dtrace_getpcstack() takes a fourth parameter, pc, that indicates 95 * an interrupted program counter (if any). This should be a non-NULL 96 * value if and only if the hit probe is unanchored. (Anchored probes 97 * don't fire through an interrupt source.) This parameter is used to 98 * assure (b), above. 99 */ 100 void 101 dtrace_getpcstack(pc_t *pcstack, int pcstack_limit, int aframes, uint32_t *pc) 102 { 103 struct frame *fp, *nextfp, *minfp, *stacktop; 104 int depth = 0; 105 int on_intr, j = 0; 106 uint32_t i, r; 107 108 fp = (struct frame *)((caddr_t)dtrace_getfp() + STACK_BIAS); 109 dtrace_flush_windows(); 110 111 if (pc != NULL) { 112 /* 113 * If we've been passed a non-NULL pc, we need to determine 114 * whether or not the specified program counter falls in a leaf 115 * function. If it falls within a leaf function, we know that 116 * %o7 is valid in its frame (and we can just drive on). If 117 * it's a non-leaf, however, we know that %o7 is garbage in the 118 * bottom frame. To trim this frame, we simply increment 119 * aframes and drop into the stack-walking loop. 120 * 121 * To quickly determine if the specified program counter is in 122 * a leaf function, we exploit the fact that leaf functions 123 * tend to be short and non-leaf functions tend to frequently 124 * perform operations that are only permitted in a non-leaf 125 * function (e.g., using the %i's or %l's; calling a function; 126 * performing a restore). We exploit these tendencies by 127 * simply scanning forward from the specified %pc -- if we see 128 * an operation only permitted in a non-leaf, we know we're in 129 * a non-leaf; if we see a retl, we know we're in a leaf. 130 * Fortunately, one need not perform anywhere near full 131 * disassembly to effectively determine the former: determining 132 * that an instruction is a format-3 instruction and decoding 133 * its rd and rs1 fields, for example, requires very little 134 * manipulation. Overall, this method of leaf determination 135 * performs quite well: on average, we only examine between 136 * 1.5 and 2.5 instructions before making the determination. 137 * (Outliers do exist, however; of note is the non-leaf 138 * function ip_sioctl_not_ours() which -- as of this writing -- 139 * has a whopping 455 straight instructions that manipulate 140 * only %g's and %o's.) 141 */ 142 int delay = 0, branches = 0, taken = 0; 143 144 if (depth < pcstack_limit) 145 pcstack[depth++] = (pc_t)(uintptr_t)pc; 146 147 /* 148 * Our heuristic is exactly that -- a heuristic -- and there 149 * exists a possibility that we could be either be vectored 150 * off into the weeds (by following a bogus branch) or could 151 * wander off the end of the function and off the end of a 152 * text mapping (by not following a conditional branch at the 153 * end of the function that is effectively always taken). So 154 * as a precautionary measure, we set the NOFAULT flag. 155 */ 156 DTRACE_CPUFLAG_SET(CPU_DTRACE_NOFAULT); 157 158 for (;;) { 159 i = pc[j++]; 160 161 if ((i & DTRACE_FMT3OP3_MASK) == DTRACE_FMT3OP3) { 162 /* 163 * This is a format-3 instruction. We can 164 * look at rd and rs1. 165 */ 166 r = (i >> DTRACE_FMT3RS1_SHIFT) & DTRACE_RMASK; 167 168 if (r >= DTRACE_REG_L0) 169 goto nonleaf; 170 171 r = (i >> DTRACE_FMT3RD_SHIFT) & DTRACE_RMASK; 172 173 if (r >= DTRACE_REG_L0) 174 goto nonleaf; 175 176 if ((i & DTRACE_JMPL_MASK) == DTRACE_JMPL) { 177 delay = 1; 178 continue; 179 } 180 181 /* 182 * If we see explicit manipulation with %o7 183 * as a destination register, we know that 184 * %o7 is likely bogus -- and we treat this 185 * function as a non-leaf. 186 */ 187 if (r == DTRACE_REG_O7) { 188 if (delay) 189 goto leaf; 190 191 i &= DTRACE_JMPL_MASK; 192 193 if (i == DTRACE_JMPL) { 194 delay = 1; 195 continue; 196 } 197 198 goto nonleaf; 199 } 200 } else { 201 /* 202 * If this is a call, it may or may not be 203 * a leaf; we need to check the delay slot. 204 */ 205 if ((i & DTRACE_CALL_MASK) == DTRACE_CALL) { 206 delay = 1; 207 continue; 208 } 209 210 /* 211 * If we see a ret it's not a leaf; if we 212 * see a retl, it is a leaf. 213 */ 214 if (i == DTRACE_RET) 215 goto nonleaf; 216 217 if (i == DTRACE_RETL) 218 goto leaf; 219 220 /* 221 * If this is a ba (annulled or not), then we 222 * need to actually follow the branch. No, we 223 * don't look at the delay slot -- hopefully 224 * anything that can be gleaned from the delay 225 * slot can also be gleaned from the branch 226 * target. To prevent ourselves from iterating 227 * infinitely, we clamp the number of branches 228 * that we'll follow, and we refuse to follow 229 * the same branch twice consecutively. In 230 * both cases, we abort by deciding that we're 231 * looking at a leaf. While in theory this 232 * could be wrong (we could be in the middle of 233 * a loop in a non-leaf that ends with a ba and 234 * only manipulates outputs and globals in the 235 * body of the loop -- therefore leading us to 236 * the wrong conclusion), this doesn't seem to 237 * crop up in practice. (Or rather, this 238 * condition could not be deliberately induced, 239 * despite concerted effort.) 240 */ 241 if ((i & DTRACE_BA_MASK) == DTRACE_BA) { 242 if (++branches == DTRACE_BA_MAX || 243 taken == j) 244 goto nonleaf; 245 246 taken = j; 247 j += ((int)(i << DTRACE_DISP22_SHIFT) >> 248 DTRACE_DISP22_SHIFT) - 1; 249 continue; 250 } 251 252 /* 253 * Finally, if it's a save, it should be 254 * treated as a leaf; if it's a restore it 255 * should not be treated as a leaf. 256 */ 257 if ((i & DTRACE_SAVE_MASK) == DTRACE_SAVE) 258 goto leaf; 259 260 if ((i & DTRACE_SAVE_MASK) == DTRACE_RESTORE) 261 goto nonleaf; 262 } 263 264 if (delay) { 265 /* 266 * If this was a delay slot instruction and 267 * we didn't pick it up elsewhere, this is a 268 * non-leaf. 269 */ 270 goto nonleaf; 271 } 272 } 273 nonleaf: 274 aframes++; 275 leaf: 276 DTRACE_CPUFLAG_CLEAR(CPU_DTRACE_NOFAULT); 277 } 278 279 if ((on_intr = CPU_ON_INTR(CPU)) != 0) 280 stacktop = (struct frame *)(CPU->cpu_intr_stack + SA(MINFRAME)); 281 else 282 stacktop = (struct frame *)curthread->t_stk; 283 minfp = fp; 284 285 while (depth < pcstack_limit) { 286 nextfp = (struct frame *)((caddr_t)fp->fr_savfp + STACK_BIAS); 287 if (nextfp <= minfp || nextfp >= stacktop) { 288 if (!on_intr && nextfp == stacktop && aframes != 0) { 289 /* 290 * If we are exactly at the top of the stack 291 * with a non-zero number of artificial frames, 292 * it must be that the stack is filled with 293 * nothing _but_ artificial frames. In this 294 * case, we assert that this is so, zero 295 * pcstack, and return. 296 */ 297 ASSERT(aframes == 1); 298 ASSERT(depth == 0); 299 300 while (depth < pcstack_limit) 301 pcstack[depth++] = NULL; 302 return; 303 } 304 305 if (on_intr) { 306 /* 307 * Hop from interrupt stack to thread stack. 308 */ 309 stacktop = (struct frame *)curthread->t_stk; 310 minfp = (struct frame *)curthread->t_stkbase; 311 312 on_intr = 0; 313 314 if (nextfp > minfp && nextfp < stacktop) 315 continue; 316 } else { 317 /* 318 * High-level interrupts may occur when %sp is 319 * not necessarily contained in the stack 320 * bounds implied by %g7 -- interrupt thread 321 * management runs with %pil at DISP_LEVEL, 322 * and high-level interrupts may thus occur 323 * in windows when %sp and %g7 are not self- 324 * consistent. If we call dtrace_getpcstack() 325 * from a high-level interrupt that has occurred 326 * in such a window, we will fail the above test 327 * of nextfp against minfp/stacktop. If the 328 * high-level interrupt has in turn interrupted 329 * a non-passivated interrupt thread, we 330 * will execute the below code with non-zero 331 * aframes. We therefore want to assert that 332 * aframes is zero _or_ we are in a high-level 333 * interrupt -- but because cpu_intr_actv is 334 * updated with high-level interrupts enabled, 335 * we must reduce this to only asserting that 336 * %pil is greater than DISP_LEVEL. 337 */ 338 ASSERT(aframes == 0 || 339 dtrace_getipl() > DISP_LEVEL); 340 pcstack[depth++] = (pc_t)fp->fr_savpc; 341 } 342 343 while (depth < pcstack_limit) 344 pcstack[depth++] = NULL; 345 return; 346 } 347 348 if (aframes > 0) { 349 aframes--; 350 } else { 351 pcstack[depth++] = (pc_t)fp->fr_savpc; 352 } 353 354 fp = nextfp; 355 minfp = fp; 356 } 357 } 358 359 static int 360 dtrace_getustack_common(uint64_t *pcstack, int pcstack_limit, uintptr_t sp) 361 { 362 proc_t *p = curproc; 363 int ret = 0; 364 365 ASSERT(pcstack == NULL || pcstack_limit > 0); 366 367 if (p->p_model == DATAMODEL_NATIVE) { 368 for (;;) { 369 struct frame *fr = (struct frame *)(sp + STACK_BIAS); 370 uintptr_t pc; 371 372 if (sp == 0 || fr == NULL || 373 !IS_P2ALIGNED((uintptr_t)fr, STACK_ALIGN)) 374 break; 375 376 pc = dtrace_fulword(&fr->fr_savpc); 377 sp = dtrace_fulword(&fr->fr_savfp); 378 379 if (pc == 0) 380 break; 381 382 ret++; 383 384 if (pcstack != NULL) { 385 *pcstack++ = pc; 386 pcstack_limit--; 387 if (pcstack_limit == 0) 388 break; 389 } 390 } 391 } else { 392 for (;;) { 393 struct frame32 *fr = (struct frame32 *)sp; 394 uint32_t pc; 395 396 if (sp == 0 || 397 !IS_P2ALIGNED((uintptr_t)fr, STACK_ALIGN32)) 398 break; 399 400 pc = dtrace_fuword32(&fr->fr_savpc); 401 sp = dtrace_fuword32(&fr->fr_savfp); 402 403 if (pc == 0) 404 break; 405 406 ret++; 407 408 if (pcstack != NULL) { 409 *pcstack++ = pc; 410 pcstack_limit--; 411 if (pcstack_limit == 0) 412 break; 413 } 414 } 415 } 416 417 return (ret); 418 } 419 420 void 421 dtrace_getupcstack(uint64_t *pcstack, int pcstack_limit) 422 { 423 klwp_t *lwp = ttolwp(curthread); 424 proc_t *p = curproc; 425 struct regs *rp; 426 uintptr_t sp; 427 int n; 428 429 if (pcstack_limit <= 0) 430 return; 431 432 /* 433 * If there's no user context we still need to zero the stack. 434 */ 435 if (lwp == NULL || p == NULL || (rp = lwp->lwp_regs) == NULL) 436 goto zero; 437 438 *pcstack++ = (uint64_t)p->p_pid; 439 pcstack_limit--; 440 441 if (pcstack_limit <= 0) 442 return; 443 444 *pcstack++ = (uint64_t)rp->r_pc; 445 pcstack_limit--; 446 447 if (pcstack_limit <= 0) 448 return; 449 450 if (DTRACE_CPUFLAG_ISSET(CPU_DTRACE_ENTRY)) { 451 *pcstack++ = (uint64_t)rp->r_o7; 452 pcstack_limit--; 453 if (pcstack_limit <= 0) 454 return; 455 } 456 457 sp = rp->r_sp; 458 459 n = dtrace_getupcstack_top(pcstack, pcstack_limit, &sp); 460 ASSERT(n >= 0); 461 ASSERT(n <= pcstack_limit); 462 463 pcstack += n; 464 pcstack_limit -= n; 465 if (pcstack_limit <= 0) 466 return; 467 468 n = dtrace_getustack_common(pcstack, pcstack_limit, sp); 469 ASSERT(n >= 0); 470 ASSERT(n <= pcstack_limit); 471 472 pcstack += n; 473 pcstack_limit -= n; 474 475 zero: 476 while (pcstack_limit-- > 0) 477 *pcstack++ = NULL; 478 } 479 480 int 481 dtrace_getustackdepth(void) 482 { 483 klwp_t *lwp = ttolwp(curthread); 484 proc_t *p = curproc; 485 struct regs *rp; 486 uintptr_t sp; 487 int n = 1; 488 489 if (lwp == NULL || p == NULL || (rp = lwp->lwp_regs) == NULL) 490 return (0); 491 492 if (DTRACE_CPUFLAG_ISSET(CPU_DTRACE_FAULT)) 493 return (-1); 494 495 sp = rp->r_sp; 496 497 n += dtrace_getustackdepth_top(&sp); 498 n += dtrace_getustack_common(NULL, 0, sp); 499 500 /* 501 * Add one more to the stack depth if we're in an entry probe as long 502 * as the return address is non-NULL or there are additional frames 503 * beyond that NULL return address. 504 */ 505 if (DTRACE_CPUFLAG_ISSET(CPU_DTRACE_ENTRY) && 506 (rp->r_o7 != NULL || n != 1)) 507 n++; 508 509 return (n); 510 } 511 512 void 513 dtrace_getufpstack(uint64_t *pcstack, uint64_t *fpstack, int pcstack_limit) 514 { 515 klwp_t *lwp = ttolwp(curthread); 516 proc_t *p = ttoproc(curthread); 517 struct regs *rp; 518 uintptr_t sp; 519 520 if (pcstack_limit <= 0) 521 return; 522 523 /* 524 * If there's no user context we still need to zero the stack. 525 */ 526 if (lwp == NULL || p == NULL || (rp = lwp->lwp_regs) == NULL) 527 goto zero; 528 529 *pcstack++ = (uint64_t)p->p_pid; 530 pcstack_limit--; 531 532 if (pcstack_limit <= 0) 533 return; 534 535 if (DTRACE_CPUFLAG_ISSET(CPU_DTRACE_ENTRY)) { 536 *fpstack++ = 0; 537 *pcstack++ = (uint64_t)rp->r_pc; 538 pcstack_limit--; 539 if (pcstack_limit <= 0) 540 return; 541 542 *fpstack++ = (uint64_t)rp->r_sp; 543 *pcstack++ = (uint64_t)rp->r_o7; 544 pcstack_limit--; 545 } else { 546 *fpstack++ = (uint64_t)rp->r_sp; 547 *pcstack++ = (uint64_t)rp->r_pc; 548 pcstack_limit--; 549 } 550 551 if (pcstack_limit <= 0) 552 return; 553 554 sp = rp->r_sp; 555 556 dtrace_flush_user_windows(); 557 558 if (p->p_model == DATAMODEL_NATIVE) { 559 while (pcstack_limit > 0) { 560 struct frame *fr = (struct frame *)(sp + STACK_BIAS); 561 uintptr_t pc; 562 563 if (sp == 0 || fr == NULL || 564 ((uintptr_t)&fr->fr_savpc & 3) != 0 || 565 ((uintptr_t)&fr->fr_savfp & 3) != 0) 566 break; 567 568 pc = dtrace_fulword(&fr->fr_savpc); 569 sp = dtrace_fulword(&fr->fr_savfp); 570 571 if (pc == 0) 572 break; 573 574 *fpstack++ = sp; 575 *pcstack++ = pc; 576 pcstack_limit--; 577 } 578 } else { 579 while (pcstack_limit > 0) { 580 struct frame32 *fr = (struct frame32 *)sp; 581 uint32_t pc; 582 583 if (sp == 0 || 584 ((uintptr_t)&fr->fr_savpc & 3) != 0 || 585 ((uintptr_t)&fr->fr_savfp & 3) != 0) 586 break; 587 588 pc = dtrace_fuword32(&fr->fr_savpc); 589 sp = dtrace_fuword32(&fr->fr_savfp); 590 591 if (pc == 0) 592 break; 593 594 *fpstack++ = sp; 595 *pcstack++ = pc; 596 pcstack_limit--; 597 } 598 } 599 600 zero: 601 while (pcstack_limit-- > 0) 602 *pcstack++ = NULL; 603 } 604 605 uint64_t 606 dtrace_getarg(int arg, int aframes) 607 { 608 uintptr_t val; 609 struct frame *fp; 610 uint64_t rval; 611 612 /* 613 * Account for the fact that dtrace_getarg() consumes an additional 614 * stack frame. 615 */ 616 aframes++; 617 618 if (arg < 6) { 619 if (dtrace_fish(aframes, DTRACE_REG_I0 + arg, &val) == 0) 620 return (val); 621 } else { 622 if (dtrace_fish(aframes, DTRACE_REG_I6, &val) == 0) { 623 /* 624 * We have a stack pointer; grab the argument. 625 */ 626 fp = (struct frame *)(val + STACK_BIAS); 627 628 DTRACE_CPUFLAG_SET(CPU_DTRACE_NOFAULT); 629 rval = fp->fr_argx[arg - 6]; 630 DTRACE_CPUFLAG_CLEAR(CPU_DTRACE_NOFAULT); 631 632 return (rval); 633 } 634 } 635 636 /* 637 * There are other ways to do this. But the slow, painful way works 638 * just fine. Because this requires some loads, we need to set 639 * CPU_DTRACE_NOFAULT to protect against looking for an argument that 640 * isn't there. 641 */ 642 fp = (struct frame *)((caddr_t)dtrace_getfp() + STACK_BIAS); 643 dtrace_flush_windows(); 644 645 DTRACE_CPUFLAG_SET(CPU_DTRACE_NOFAULT); 646 647 for (aframes -= 1; aframes; aframes--) 648 fp = (struct frame *)((caddr_t)fp->fr_savfp + STACK_BIAS); 649 650 if (arg < 6) { 651 rval = fp->fr_arg[arg]; 652 } else { 653 fp = (struct frame *)((caddr_t)fp->fr_savfp + STACK_BIAS); 654 rval = fp->fr_argx[arg - 6]; 655 } 656 657 DTRACE_CPUFLAG_CLEAR(CPU_DTRACE_NOFAULT); 658 659 return (rval); 660 } 661 662 int 663 dtrace_getstackdepth(int aframes) 664 { 665 struct frame *fp, *nextfp, *minfp, *stacktop; 666 int depth = 0; 667 int on_intr; 668 669 fp = (struct frame *)((caddr_t)dtrace_getfp() + STACK_BIAS); 670 dtrace_flush_windows(); 671 672 if ((on_intr = CPU_ON_INTR(CPU)) != 0) 673 stacktop = (struct frame *)CPU->cpu_intr_stack + SA(MINFRAME); 674 else 675 stacktop = (struct frame *)curthread->t_stk; 676 minfp = fp; 677 678 for (;;) { 679 nextfp = (struct frame *)((caddr_t)fp->fr_savfp + STACK_BIAS); 680 if (nextfp <= minfp || nextfp >= stacktop) { 681 if (on_intr) { 682 /* 683 * Hop from interrupt stack to thread stack. 684 */ 685 stacktop = (struct frame *)curthread->t_stk; 686 minfp = (struct frame *)curthread->t_stkbase; 687 on_intr = 0; 688 continue; 689 } 690 691 return (++depth); 692 } 693 694 if (aframes > 0) { 695 aframes--; 696 } else { 697 depth++; 698 } 699 700 fp = nextfp; 701 minfp = fp; 702 } 703 } 704 705 /* 706 * This uses the same register numbering scheme as in sys/procfs_isa.h. 707 */ 708 ulong_t 709 dtrace_getreg(struct regs *rp, uint_t reg) 710 { 711 ulong_t value; 712 uintptr_t fp; 713 struct machpcb *mpcb; 714 715 if (reg == R_G0) 716 return (0); 717 718 if (reg <= R_G7) 719 return ((&rp->r_g1)[reg - 1]); 720 721 if (reg > R_I7) { 722 switch (reg) { 723 case R_CCR: 724 return ((rp->r_tstate >> TSTATE_CCR_SHIFT) & 725 TSTATE_CCR_MASK); 726 case R_PC: 727 return (rp->r_pc); 728 case R_nPC: 729 return (rp->r_npc); 730 case R_Y: 731 return (rp->r_y); 732 case R_ASI: 733 return ((rp->r_tstate >> TSTATE_ASI_SHIFT) & 734 TSTATE_ASI_MASK); 735 case R_FPRS: 736 return (dtrace_getfprs()); 737 default: 738 DTRACE_CPUFLAG_SET(CPU_DTRACE_ILLOP); 739 return (0); 740 } 741 } 742 743 /* 744 * We reach go to the fake restore case if the probe we hit was a pid 745 * return probe on a restore instruction. We partially emulate the 746 * restore in the kernel and then execute a simple restore 747 * instruction that we've secreted away to do the actual register 748 * window manipulation. We need to go one register window further 749 * down to get at the %ls, and %is and we need to treat %os like %is 750 * to pull them out of the topmost user frame. 751 */ 752 if (DTRACE_CPUFLAG_ISSET(CPU_DTRACE_FAKERESTORE)) { 753 if (reg > R_O7) 754 goto fake_restore; 755 else 756 reg += R_I0 - R_O0; 757 758 } else if (reg <= R_O7) { 759 return ((&rp->r_g1)[reg - 1]); 760 } 761 762 if (dtrace_getotherwin() > 0) 763 return (dtrace_getreg_win(reg, 1)); 764 765 mpcb = (struct machpcb *)((caddr_t)rp - REGOFF); 766 767 if (curproc->p_model == DATAMODEL_NATIVE) { 768 struct frame *fr = (void *)(rp->r_sp + STACK_BIAS); 769 770 if (mpcb->mpcb_wbcnt > 0) { 771 struct rwindow *rwin = (void *)mpcb->mpcb_wbuf; 772 int i = mpcb->mpcb_wbcnt; 773 do { 774 i--; 775 if ((long)mpcb->mpcb_spbuf[i] == rp->r_sp) 776 return (rwin[i].rw_local[reg - 16]); 777 } while (i > 0); 778 } 779 780 DTRACE_CPUFLAG_SET(CPU_DTRACE_NOFAULT); 781 value = dtrace_fulword(&fr->fr_local[reg - 16]); 782 DTRACE_CPUFLAG_CLEAR(CPU_DTRACE_NOFAULT); 783 } else { 784 struct frame32 *fr = (void *)(uintptr_t)(caddr32_t)rp->r_sp; 785 786 if (mpcb->mpcb_wbcnt > 0) { 787 struct rwindow32 *rwin = (void *)mpcb->mpcb_wbuf; 788 int i = mpcb->mpcb_wbcnt; 789 do { 790 i--; 791 if ((long)mpcb->mpcb_spbuf[i] == rp->r_sp) 792 return (rwin[i].rw_local[reg - 16]); 793 } while (i > 0); 794 } 795 796 DTRACE_CPUFLAG_SET(CPU_DTRACE_NOFAULT); 797 value = dtrace_fuword32(&fr->fr_local[reg - 16]); 798 DTRACE_CPUFLAG_CLEAR(CPU_DTRACE_NOFAULT); 799 } 800 801 return (value); 802 803 fake_restore: 804 ASSERT(R_L0 <= reg && reg <= R_I7); 805 806 /* 807 * We first look two user windows down to see if we can dig out 808 * the register we're looking for. 809 */ 810 if (dtrace_getotherwin() > 1) 811 return (dtrace_getreg_win(reg, 2)); 812 813 /* 814 * First we need to get the frame pointer and then we perform 815 * the same computation as in the non-fake-o-restore case. 816 */ 817 818 mpcb = (struct machpcb *)((caddr_t)rp - REGOFF); 819 820 if (dtrace_getotherwin() > 0) { 821 fp = dtrace_getreg_win(R_FP, 1); 822 goto got_fp; 823 } 824 825 if (curproc->p_model == DATAMODEL_NATIVE) { 826 struct frame *fr = (void *)(rp->r_sp + STACK_BIAS); 827 828 if (mpcb->mpcb_wbcnt > 0) { 829 struct rwindow *rwin = (void *)mpcb->mpcb_wbuf; 830 int i = mpcb->mpcb_wbcnt; 831 do { 832 i--; 833 if ((long)mpcb->mpcb_spbuf[i] == rp->r_sp) { 834 fp = rwin[i].rw_fp; 835 goto got_fp; 836 } 837 } while (i > 0); 838 } 839 840 DTRACE_CPUFLAG_SET(CPU_DTRACE_NOFAULT); 841 fp = dtrace_fulword(&fr->fr_savfp); 842 DTRACE_CPUFLAG_CLEAR(CPU_DTRACE_NOFAULT); 843 if (cpu_core[CPU->cpu_id].cpuc_dtrace_flags & CPU_DTRACE_FAULT) 844 return (0); 845 } else { 846 struct frame32 *fr = (void *)(uintptr_t)(caddr32_t)rp->r_sp; 847 848 if (mpcb->mpcb_wbcnt > 0) { 849 struct rwindow32 *rwin = (void *)mpcb->mpcb_wbuf; 850 int i = mpcb->mpcb_wbcnt; 851 do { 852 i--; 853 if ((long)mpcb->mpcb_spbuf[i] == rp->r_sp) { 854 fp = rwin[i].rw_fp; 855 goto got_fp; 856 } 857 } while (i > 0); 858 } 859 860 DTRACE_CPUFLAG_SET(CPU_DTRACE_NOFAULT); 861 fp = dtrace_fuword32(&fr->fr_savfp); 862 DTRACE_CPUFLAG_CLEAR(CPU_DTRACE_NOFAULT); 863 if (cpu_core[CPU->cpu_id].cpuc_dtrace_flags & CPU_DTRACE_FAULT) 864 return (0); 865 } 866 got_fp: 867 868 if (curproc->p_model == DATAMODEL_NATIVE) { 869 struct frame *fr = (void *)(fp + STACK_BIAS); 870 871 if (mpcb->mpcb_wbcnt > 0) { 872 struct rwindow *rwin = (void *)mpcb->mpcb_wbuf; 873 int i = mpcb->mpcb_wbcnt; 874 do { 875 i--; 876 if ((long)mpcb->mpcb_spbuf[i] == fp) 877 return (rwin[i].rw_local[reg - 16]); 878 } while (i > 0); 879 } 880 881 DTRACE_CPUFLAG_SET(CPU_DTRACE_NOFAULT); 882 value = dtrace_fulword(&fr->fr_local[reg - 16]); 883 DTRACE_CPUFLAG_CLEAR(CPU_DTRACE_NOFAULT); 884 } else { 885 struct frame32 *fr = (void *)(uintptr_t)(caddr32_t)fp; 886 887 if (mpcb->mpcb_wbcnt > 0) { 888 struct rwindow32 *rwin = (void *)mpcb->mpcb_wbuf; 889 int i = mpcb->mpcb_wbcnt; 890 do { 891 i--; 892 if ((long)mpcb->mpcb_spbuf[i] == fp) 893 return (rwin[i].rw_local[reg - 16]); 894 } while (i > 0); 895 } 896 897 DTRACE_CPUFLAG_SET(CPU_DTRACE_NOFAULT); 898 value = dtrace_fuword32(&fr->fr_local[reg - 16]); 899 DTRACE_CPUFLAG_CLEAR(CPU_DTRACE_NOFAULT); 900 } 901 902 return (value); 903 } 904