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 2010 Sun Microsystems, Inc. All rights reserved. 24 * Use is subject to license terms. 25 */ 26 27 /* Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T */ 28 /* All Rights Reserved */ 29 30 #include <sys/param.h> 31 #include <sys/types.h> 32 #include <sys/vmparam.h> 33 #include <sys/systm.h> 34 #include <sys/signal.h> 35 #include <sys/stack.h> 36 #include <sys/frame.h> 37 #include <sys/proc.h> 38 #include <sys/ucontext.h> 39 #include <sys/asm_linkage.h> 40 #include <sys/kmem.h> 41 #include <sys/errno.h> 42 #include <sys/archsystm.h> 43 #include <sys/fpu/fpusystm.h> 44 #include <sys/debug.h> 45 #include <sys/model.h> 46 #include <sys/cmn_err.h> 47 #include <sys/sysmacros.h> 48 #include <sys/privregs.h> 49 #include <sys/schedctl.h> 50 51 52 /* 53 * Save user context. 54 */ 55 void 56 savecontext(ucontext_t *ucp, const k_sigset_t *mask) 57 { 58 proc_t *p = ttoproc(curthread); 59 klwp_t *lwp = ttolwp(curthread); 60 61 /* 62 * We assign to every field through uc_mcontext.fpregs.fpu_en, 63 * but we have to bzero() everything after that. 64 */ 65 bzero(&ucp->uc_mcontext.fpregs.fpu_en, sizeof (ucontext_t) - 66 offsetof(ucontext_t, uc_mcontext.fpregs.fpu_en)); 67 /* 68 * There are unused holes in the ucontext_t structure, zero-fill 69 * them so that we don't expose kernel data to the user. 70 */ 71 (&ucp->uc_flags)[1] = 0; 72 (&ucp->uc_stack.ss_flags)[1] = 0; 73 74 /* 75 * Flushing the user windows isn't strictly necessary; we do 76 * it to maintain backward compatibility. 77 */ 78 (void) flush_user_windows_to_stack(NULL); 79 80 ucp->uc_flags = UC_ALL; 81 ucp->uc_link = (ucontext_t *)lwp->lwp_oldcontext; 82 83 /* 84 * Try to copyin() the ustack if one is registered. If the stack 85 * has zero size, this indicates that stack bounds checking has 86 * been disabled for this LWP. If stack bounds checking is disabled 87 * or the copyin() fails, we fall back to the legacy behavior. 88 */ 89 if (lwp->lwp_ustack == NULL || 90 copyin((void *)lwp->lwp_ustack, &ucp->uc_stack, 91 sizeof (ucp->uc_stack)) != 0 || 92 ucp->uc_stack.ss_size == 0) { 93 94 if (lwp->lwp_sigaltstack.ss_flags == SS_ONSTACK) { 95 ucp->uc_stack = lwp->lwp_sigaltstack; 96 } else { 97 ucp->uc_stack.ss_sp = p->p_usrstack - p->p_stksize; 98 ucp->uc_stack.ss_size = p->p_stksize; 99 ucp->uc_stack.ss_flags = 0; 100 } 101 } 102 103 getgregs(lwp, ucp->uc_mcontext.gregs); 104 getasrs(lwp, ucp->uc_mcontext.asrs); 105 106 getfpregs(lwp, &ucp->uc_mcontext.fpregs); 107 getfpasrs(lwp, ucp->uc_mcontext.asrs); 108 if (ucp->uc_mcontext.fpregs.fpu_en == 0) 109 ucp->uc_flags &= ~UC_FPU; 110 ucp->uc_mcontext.gwins = (gwindows_t *)NULL; 111 112 /* 113 * Save signal mask. 114 */ 115 sigktou(mask, &ucp->uc_sigmask); 116 } 117 118 119 void 120 restorecontext(ucontext_t *ucp) 121 { 122 kthread_t *t = curthread; 123 klwp_t *lwp = ttolwp(t); 124 mcontext_t *mcp = &ucp->uc_mcontext; 125 model_t model = lwp_getdatamodel(lwp); 126 127 (void) flush_user_windows_to_stack(NULL); 128 if (lwp->lwp_pcb.pcb_xregstat != XREGNONE) 129 xregrestore(lwp, 0); 130 131 lwp->lwp_oldcontext = (uintptr_t)ucp->uc_link; 132 133 if (ucp->uc_flags & UC_STACK) { 134 if (ucp->uc_stack.ss_flags == SS_ONSTACK) 135 lwp->lwp_sigaltstack = ucp->uc_stack; 136 else 137 lwp->lwp_sigaltstack.ss_flags &= ~SS_ONSTACK; 138 } 139 140 if (ucp->uc_flags & UC_CPU) { 141 if (mcp->gwins != 0) 142 setgwins(lwp, mcp->gwins); 143 setgregs(lwp, mcp->gregs); 144 if (model == DATAMODEL_LP64) 145 setasrs(lwp, mcp->asrs); 146 else 147 xregs_setgregs(lwp, xregs_getptr(lwp, ucp)); 148 } 149 150 if (ucp->uc_flags & UC_FPU) { 151 fpregset_t *fp = &ucp->uc_mcontext.fpregs; 152 153 setfpregs(lwp, fp); 154 if (model == DATAMODEL_LP64) 155 setfpasrs(lwp, mcp->asrs); 156 else 157 xregs_setfpregs(lwp, xregs_getptr(lwp, ucp)); 158 run_fpq(lwp, fp); 159 } 160 161 if (ucp->uc_flags & UC_SIGMASK) { 162 /* 163 * We don't need to acquire p->p_lock here; 164 * we are manipulating thread-private data. 165 */ 166 schedctl_finish_sigblock(t); 167 sigutok(&ucp->uc_sigmask, &t->t_hold); 168 if (sigcheck(ttoproc(t), t)) 169 t->t_sig_check = 1; 170 } 171 } 172 173 174 int 175 getsetcontext(int flag, void *arg) 176 { 177 ucontext_t uc; 178 struct fq fpu_q[MAXFPQ]; /* to hold floating queue */ 179 fpregset_t *fpp; 180 gwindows_t *gwin = NULL; /* to hold windows */ 181 caddr_t xregs = NULL; 182 int xregs_size = 0; 183 extern int nwindows; 184 ucontext_t *ucp; 185 klwp_t *lwp = ttolwp(curthread); 186 stack_t dummy_stk; 187 188 /* 189 * In future releases, when the ucontext structure grows, 190 * getcontext should be modified to only return the fields 191 * specified in the uc_flags. That way, the structure can grow 192 * and still be binary compatible will all .o's which will only 193 * have old fields defined in uc_flags 194 */ 195 196 switch (flag) { 197 default: 198 return (set_errno(EINVAL)); 199 200 case GETCONTEXT: 201 schedctl_finish_sigblock(curthread); 202 savecontext(&uc, &curthread->t_hold); 203 /* 204 * When using floating point it should not be possible to 205 * get here with a fpu_qcnt other than zero since we go 206 * to great pains to handle all outstanding FP exceptions 207 * before any system call code gets executed. However we 208 * clear fpu_q and fpu_qcnt here before copyout anyway - 209 * this will prevent us from interpreting the garbage we 210 * get back (when FP is not enabled) as valid queue data on 211 * a later setcontext(2). 212 */ 213 uc.uc_mcontext.fpregs.fpu_qcnt = 0; 214 uc.uc_mcontext.fpregs.fpu_q = (struct fq *)NULL; 215 216 if (copyout(&uc, arg, sizeof (ucontext_t))) 217 return (set_errno(EFAULT)); 218 return (0); 219 220 case SETCONTEXT: 221 ucp = arg; 222 if (ucp == NULL) 223 exit(CLD_EXITED, 0); 224 /* 225 * Don't copyin filler or floating state unless we need it. 226 * The ucontext_t struct and fields are specified in the ABI. 227 */ 228 if (copyin(ucp, &uc, sizeof (ucontext_t) - 229 sizeof (uc.uc_filler) - 230 sizeof (uc.uc_mcontext.fpregs) - 231 sizeof (uc.uc_mcontext.xrs) - 232 sizeof (uc.uc_mcontext.asrs) - 233 sizeof (uc.uc_mcontext.filler))) { 234 return (set_errno(EFAULT)); 235 } 236 if (copyin(&ucp->uc_mcontext.xrs, &uc.uc_mcontext.xrs, 237 sizeof (uc.uc_mcontext.xrs))) { 238 return (set_errno(EFAULT)); 239 } 240 fpp = &uc.uc_mcontext.fpregs; 241 if (uc.uc_flags & UC_FPU) { 242 /* 243 * Need to copyin floating point state 244 */ 245 if (copyin(&ucp->uc_mcontext.fpregs, 246 &uc.uc_mcontext.fpregs, 247 sizeof (uc.uc_mcontext.fpregs))) 248 return (set_errno(EFAULT)); 249 /* if floating queue not empty */ 250 if ((fpp->fpu_q) && (fpp->fpu_qcnt)) { 251 if (fpp->fpu_qcnt > MAXFPQ || 252 fpp->fpu_q_entrysize <= 0 || 253 fpp->fpu_q_entrysize > sizeof (struct fq)) 254 return (set_errno(EINVAL)); 255 if (copyin(fpp->fpu_q, fpu_q, 256 fpp->fpu_qcnt * fpp->fpu_q_entrysize)) 257 return (set_errno(EFAULT)); 258 fpp->fpu_q = fpu_q; 259 } else { 260 fpp->fpu_qcnt = 0; /* avoid confusion later */ 261 } 262 } else { 263 fpp->fpu_qcnt = 0; 264 } 265 if (uc.uc_mcontext.gwins) { /* if windows in context */ 266 size_t gwin_size; 267 268 /* 269 * We do the same computation here to determine 270 * how many bytes of gwindows_t to copy in that 271 * is also done in sendsig() to decide how many 272 * bytes to copy out. We just *know* that wbcnt 273 * is the first element of the structure. 274 */ 275 gwin = kmem_zalloc(sizeof (gwindows_t), KM_SLEEP); 276 if (copyin(uc.uc_mcontext.gwins, 277 &gwin->wbcnt, sizeof (gwin->wbcnt))) { 278 kmem_free(gwin, sizeof (gwindows_t)); 279 return (set_errno(EFAULT)); 280 } 281 if (gwin->wbcnt < 0 || gwin->wbcnt > nwindows) { 282 kmem_free(gwin, sizeof (gwindows_t)); 283 return (set_errno(EINVAL)); 284 } 285 gwin_size = gwin->wbcnt * sizeof (struct rwindow) + 286 SPARC_MAXREGWINDOW * sizeof (int *) + sizeof (long); 287 if (gwin_size > sizeof (gwindows_t) || 288 copyin(uc.uc_mcontext.gwins, gwin, gwin_size)) { 289 kmem_free(gwin, sizeof (gwindows_t)); 290 return (set_errno(EFAULT)); 291 } 292 uc.uc_mcontext.gwins = gwin; 293 } 294 295 /* 296 * get extra register state or asrs if any exists 297 * there is no extra register state for _LP64 user programs 298 */ 299 xregs_clrptr(lwp, &uc); 300 if (copyin(&ucp->uc_mcontext.asrs, &uc.uc_mcontext.asrs, 301 sizeof (asrset_t))) { 302 /* Free up gwin structure if used */ 303 if (gwin) 304 kmem_free(gwin, sizeof (gwindows_t)); 305 return (set_errno(EFAULT)); 306 } 307 308 restorecontext(&uc); 309 310 if ((uc.uc_flags & UC_STACK) && (lwp->lwp_ustack != 0)) { 311 (void) copyout(&uc.uc_stack, (stack_t *)lwp->lwp_ustack, 312 sizeof (stack_t)); 313 } 314 315 /* 316 * free extra register state area 317 */ 318 if (xregs_size) 319 kmem_free(xregs, xregs_size); 320 321 if (gwin) 322 kmem_free(gwin, sizeof (gwindows_t)); 323 324 return (0); 325 326 case GETUSTACK: 327 if (copyout(&lwp->lwp_ustack, arg, sizeof (caddr_t))) 328 return (set_errno(EFAULT)); 329 330 return (0); 331 332 case SETUSTACK: 333 if (copyin(arg, &dummy_stk, sizeof (dummy_stk))) 334 return (set_errno(EFAULT)); 335 336 lwp->lwp_ustack = (uintptr_t)arg; 337 338 return (0); 339 } 340 } 341 342 343 #ifdef _SYSCALL32_IMPL 344 345 /* 346 * Save user context for 32-bit processes. 347 */ 348 void 349 savecontext32(ucontext32_t *ucp, const k_sigset_t *mask, struct fq32 *dfq) 350 { 351 proc_t *p = ttoproc(curthread); 352 klwp_t *lwp = ttolwp(curthread); 353 fpregset_t fpregs; 354 355 /* 356 * We assign to every field through uc_mcontext.fpregs.fpu_en, 357 * but we have to bzero() everything after that. 358 */ 359 bzero(&ucp->uc_mcontext.fpregs.fpu_en, sizeof (ucontext32_t) - 360 offsetof(ucontext32_t, uc_mcontext.fpregs.fpu_en)); 361 /* 362 * There is an unused hole in the ucontext32_t structure; zero-fill 363 * it so that we don't expose kernel data to the user. 364 */ 365 (&ucp->uc_stack.ss_flags)[1] = 0; 366 367 /* 368 * Flushing the user windows isn't strictly necessary; we do 369 * it to maintain backward compatibility. 370 */ 371 (void) flush_user_windows_to_stack(NULL); 372 373 ucp->uc_flags = UC_ALL; 374 ucp->uc_link = (caddr32_t)lwp->lwp_oldcontext; 375 376 /* 377 * Try to copyin() the ustack if one is registered. If the stack 378 * has zero size, this indicates that stack bounds checking has 379 * been disabled for this LWP. If stack bounds checking is disabled 380 * or the copyin() fails, we fall back to the legacy behavior. 381 */ 382 if (lwp->lwp_ustack == NULL || 383 copyin((void *)lwp->lwp_ustack, &ucp->uc_stack, 384 sizeof (ucp->uc_stack)) != 0 || 385 ucp->uc_stack.ss_size == 0) { 386 387 if (lwp->lwp_sigaltstack.ss_flags == SS_ONSTACK) { 388 ucp->uc_stack.ss_sp = 389 (caddr32_t)(uintptr_t)lwp->lwp_sigaltstack.ss_sp; 390 ucp->uc_stack.ss_size = 391 (size32_t)lwp->lwp_sigaltstack.ss_size; 392 ucp->uc_stack.ss_flags = SS_ONSTACK; 393 } else { 394 ucp->uc_stack.ss_sp = 395 (caddr32_t)(uintptr_t)p->p_usrstack - p->p_stksize; 396 ucp->uc_stack.ss_size = 397 (size32_t)p->p_stksize; 398 ucp->uc_stack.ss_flags = 0; 399 } 400 } 401 402 getgregs32(lwp, ucp->uc_mcontext.gregs); 403 getfpregs(lwp, &fpregs); 404 fpuregset_nto32(&fpregs, &ucp->uc_mcontext.fpregs, dfq); 405 406 if (ucp->uc_mcontext.fpregs.fpu_en == 0) 407 ucp->uc_flags &= ~UC_FPU; 408 ucp->uc_mcontext.gwins = (caddr32_t)NULL; 409 410 /* 411 * Save signal mask (the 32- and 64-bit sigset_t structures are 412 * identical). 413 */ 414 sigktou(mask, (sigset_t *)&ucp->uc_sigmask); 415 } 416 417 int 418 getsetcontext32(int flag, void *arg) 419 { 420 ucontext32_t uc; 421 ucontext_t ucnat; 422 struct fq fpu_qnat[MAXFPQ]; /* to hold "native" floating queue */ 423 struct fq32 fpu_q[MAXFPQ]; /* to hold 32 bit floating queue */ 424 fpregset32_t *fpp; 425 gwindows32_t *gwin = NULL; /* to hold windows */ 426 caddr_t xregs; 427 int xregs_size = 0; 428 extern int nwindows; 429 klwp_t *lwp = ttolwp(curthread); 430 ucontext32_t *ucp; 431 uint32_t ustack32; 432 stack32_t dummy_stk32; 433 434 /* 435 * In future releases, when the ucontext structure grows, 436 * getcontext should be modified to only return the fields 437 * specified in the uc_flags. That way, the structure can grow 438 * and still be binary compatible will all .o's which will only 439 * have old fields defined in uc_flags 440 */ 441 442 switch (flag) { 443 default: 444 return (set_errno(EINVAL)); 445 446 case GETCONTEXT: 447 schedctl_finish_sigblock(curthread); 448 savecontext32(&uc, &curthread->t_hold, NULL); 449 /* 450 * When using floating point it should not be possible to 451 * get here with a fpu_qcnt other than zero since we go 452 * to great pains to handle all outstanding FP exceptions 453 * before any system call code gets executed. However we 454 * clear fpu_q and fpu_qcnt here before copyout anyway - 455 * this will prevent us from interpreting the garbage we 456 * get back (when FP is not enabled) as valid queue data on 457 * a later setcontext(2). 458 */ 459 uc.uc_mcontext.fpregs.fpu_qcnt = 0; 460 uc.uc_mcontext.fpregs.fpu_q = (caddr32_t)NULL; 461 462 if (copyout(&uc, arg, sizeof (ucontext32_t))) 463 return (set_errno(EFAULT)); 464 return (0); 465 466 case SETCONTEXT: 467 ucp = arg; 468 if (ucp == NULL) 469 exit(CLD_EXITED, 0); 470 /* 471 * Don't copyin filler or floating state unless we need it. 472 * The ucontext_t struct and fields are specified in the ABI. 473 */ 474 if (copyin(ucp, &uc, sizeof (uc) - sizeof (uc.uc_filler) - 475 sizeof (uc.uc_mcontext.fpregs) - 476 sizeof (uc.uc_mcontext.xrs) - 477 sizeof (uc.uc_mcontext.filler))) { 478 return (set_errno(EFAULT)); 479 } 480 if (copyin(&ucp->uc_mcontext.xrs, &uc.uc_mcontext.xrs, 481 sizeof (uc.uc_mcontext.xrs))) { 482 return (set_errno(EFAULT)); 483 } 484 fpp = &uc.uc_mcontext.fpregs; 485 if (uc.uc_flags & UC_FPU) { 486 /* 487 * Need to copyin floating point state 488 */ 489 if (copyin(&ucp->uc_mcontext.fpregs, 490 &uc.uc_mcontext.fpregs, 491 sizeof (uc.uc_mcontext.fpregs))) 492 return (set_errno(EFAULT)); 493 /* if floating queue not empty */ 494 if ((fpp->fpu_q) && (fpp->fpu_qcnt)) { 495 if (fpp->fpu_qcnt > MAXFPQ || 496 fpp->fpu_q_entrysize <= 0 || 497 fpp->fpu_q_entrysize > sizeof (struct fq32)) 498 return (set_errno(EINVAL)); 499 if (copyin((void *)(uintptr_t)fpp->fpu_q, fpu_q, 500 fpp->fpu_qcnt * fpp->fpu_q_entrysize)) 501 return (set_errno(EFAULT)); 502 } else { 503 fpp->fpu_qcnt = 0; /* avoid confusion later */ 504 } 505 } else { 506 fpp->fpu_qcnt = 0; 507 } 508 509 if (uc.uc_mcontext.gwins) { /* if windows in context */ 510 size_t gwin_size; 511 512 /* 513 * We do the same computation here to determine 514 * how many bytes of gwindows_t to copy in that 515 * is also done in sendsig() to decide how many 516 * bytes to copy out. We just *know* that wbcnt 517 * is the first element of the structure. 518 */ 519 gwin = kmem_zalloc(sizeof (gwindows32_t), KM_SLEEP); 520 if (copyin((void *)(uintptr_t)uc.uc_mcontext.gwins, 521 &gwin->wbcnt, sizeof (gwin->wbcnt))) { 522 kmem_free(gwin, sizeof (gwindows32_t)); 523 return (set_errno(EFAULT)); 524 } 525 if (gwin->wbcnt < 0 || gwin->wbcnt > nwindows) { 526 kmem_free(gwin, sizeof (gwindows32_t)); 527 return (set_errno(EINVAL)); 528 } 529 gwin_size = gwin->wbcnt * sizeof (struct rwindow32) + 530 SPARC_MAXREGWINDOW * sizeof (caddr32_t) + 531 sizeof (int32_t); 532 if (gwin_size > sizeof (gwindows32_t) || 533 copyin((void *)(uintptr_t)uc.uc_mcontext.gwins, 534 gwin, gwin_size)) { 535 kmem_free(gwin, sizeof (gwindows32_t)); 536 return (set_errno(EFAULT)); 537 } 538 /* restorecontext() should ignore this */ 539 uc.uc_mcontext.gwins = (caddr32_t)0; 540 } 541 542 ucontext_32ton(&uc, &ucnat, fpu_q, fpu_qnat); 543 544 /* 545 * get extra register state if any exists 546 */ 547 if (xregs_hasptr32(lwp, &uc) && 548 ((xregs_size = xregs_getsize(curproc)) > 0)) { 549 xregs = kmem_zalloc(xregs_size, KM_SLEEP); 550 if (copyin((void *)(uintptr_t)xregs_getptr32(lwp, &uc), 551 xregs, xregs_size)) { 552 kmem_free(xregs, xregs_size); 553 if (gwin) 554 kmem_free(gwin, sizeof (gwindows32_t)); 555 return (set_errno(EFAULT)); 556 } 557 xregs_setptr(lwp, &ucnat, xregs); 558 } else { 559 xregs_clrptr(lwp, &ucnat); 560 } 561 562 restorecontext(&ucnat); 563 564 if ((uc.uc_flags & UC_STACK) && (lwp->lwp_ustack != 0)) { 565 (void) copyout(&uc.uc_stack, 566 (stack32_t *)lwp->lwp_ustack, sizeof (stack32_t)); 567 } 568 569 if (gwin) 570 setgwins32(lwp, gwin); 571 572 /* 573 * free extra register state area 574 */ 575 if (xregs_size) 576 kmem_free(xregs, xregs_size); 577 578 if (gwin) 579 kmem_free(gwin, sizeof (gwindows32_t)); 580 581 return (0); 582 583 case GETUSTACK: 584 ustack32 = (uint32_t)lwp->lwp_ustack; 585 if (copyout(&ustack32, arg, sizeof (caddr32_t))) 586 return (set_errno(EFAULT)); 587 588 return (0); 589 590 case SETUSTACK: 591 if (copyin(arg, &dummy_stk32, sizeof (dummy_stk32))) 592 return (set_errno(EFAULT)); 593 594 lwp->lwp_ustack = (uintptr_t)arg; 595 596 return (0); 597 } 598 } 599 600 #endif /* _SYSCALL32_IMPL */ 601