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 2007 Sun Microsystems, Inc. All rights reserved. 24 * Use is subject to license terms. 25 */ 26 27 /* Copyright (c) 1990, 1991 UNIX System Laboratories, Inc. */ 28 /* Copyright (c) 1984, 1986, 1987, 1988, 1989, 1990 AT&T */ 29 /* All Rights Reserved */ 30 31 #pragma ident "%Z%%M% %I% %E% SMI" 32 33 #include <sys/types.h> 34 #include <sys/param.h> 35 #include <sys/sysmacros.h> 36 #include <sys/signal.h> 37 #include <sys/systm.h> 38 #include <sys/user.h> 39 #include <sys/mman.h> 40 #include <sys/class.h> 41 #include <sys/proc.h> 42 #include <sys/procfs.h> 43 #include <sys/buf.h> 44 #include <sys/kmem.h> 45 #include <sys/cred.h> 46 #include <sys/archsystm.h> 47 #include <sys/vmparam.h> 48 #include <sys/prsystm.h> 49 #include <sys/reboot.h> 50 #include <sys/uadmin.h> 51 #include <sys/vfs.h> 52 #include <sys/vnode.h> 53 #include <sys/file.h> 54 #include <sys/session.h> 55 #include <sys/ucontext.h> 56 #include <sys/dnlc.h> 57 #include <sys/var.h> 58 #include <sys/cmn_err.h> 59 #include <sys/debugreg.h> 60 #include <sys/thread.h> 61 #include <sys/vtrace.h> 62 #include <sys/consdev.h> 63 #include <sys/psw.h> 64 #include <sys/regset.h> 65 66 #include <sys/privregs.h> 67 68 #include <sys/stack.h> 69 #include <sys/swap.h> 70 #include <vm/hat.h> 71 #include <vm/anon.h> 72 #include <vm/as.h> 73 #include <vm/page.h> 74 #include <vm/seg.h> 75 #include <vm/seg_kmem.h> 76 #include <vm/seg_map.h> 77 #include <vm/seg_vn.h> 78 #include <sys/exec.h> 79 #include <sys/acct.h> 80 #include <sys/core.h> 81 #include <sys/corectl.h> 82 #include <sys/modctl.h> 83 #include <sys/tuneable.h> 84 #include <c2/audit.h> 85 #include <sys/bootconf.h> 86 #include <sys/dumphdr.h> 87 #include <sys/promif.h> 88 #include <sys/systeminfo.h> 89 #include <sys/kdi.h> 90 #include <sys/contract_impl.h> 91 #include <sys/x86_archext.h> 92 93 /* 94 * Construct the execution environment for the user's signal 95 * handler and arrange for control to be given to it on return 96 * to userland. The library code now calls setcontext() to 97 * clean up after the signal handler, so sigret() is no longer 98 * needed. 99 * 100 * (The various 'volatile' declarations are need to ensure that values 101 * are correct on the error return from on_fault().) 102 */ 103 104 #if defined(__amd64) 105 106 /* 107 * An amd64 signal frame looks like this on the stack: 108 * 109 * old %rsp: 110 * <128 bytes of untouched stack space> 111 * <a siginfo_t [optional]> 112 * <a ucontext_t> 113 * <siginfo_t *> 114 * <signal number> 115 * new %rsp: <return address (deliberately invalid)> 116 * 117 * The signal number and siginfo_t pointer are only pushed onto the stack in 118 * order to allow stack backtraces. The actual signal handling code expects the 119 * arguments in registers. 120 */ 121 122 struct sigframe { 123 caddr_t retaddr; 124 long signo; 125 siginfo_t *sip; 126 }; 127 128 int 129 sendsig(int sig, k_siginfo_t *sip, void (*hdlr)()) 130 { 131 volatile int minstacksz; 132 int newstack; 133 label_t ljb; 134 volatile caddr_t sp; 135 caddr_t fp; 136 volatile struct regs *rp; 137 volatile greg_t upc; 138 volatile proc_t *p = ttoproc(curthread); 139 klwp_t *lwp = ttolwp(curthread); 140 ucontext_t *volatile tuc = NULL; 141 ucontext_t *uc; 142 siginfo_t *sip_addr; 143 volatile int watched; 144 145 /* 146 * This routine is utterly dependent upon STACK_ALIGN being 147 * 16 and STACK_ENTRY_ALIGN being 8. Let's just acknowledge 148 * that and require it. 149 */ 150 151 #if STACK_ALIGN != 16 || STACK_ENTRY_ALIGN != 8 152 #error "sendsig() amd64 did not find the expected stack alignments" 153 #endif 154 155 rp = lwptoregs(lwp); 156 upc = rp->r_pc; 157 158 /* 159 * Since we're setting up to run the signal handler we have to 160 * arrange that the stack at entry to the handler is (only) 161 * STACK_ENTRY_ALIGN (i.e. 8) byte aligned so that when the handler 162 * executes its push of %rbp, the stack realigns to STACK_ALIGN 163 * (i.e. 16) correctly. 164 * 165 * The new sp will point to the sigframe and the ucontext_t. The 166 * above means that sp (and thus sigframe) will be 8-byte aligned, 167 * but not 16-byte aligned. ucontext_t, however, contains %xmm regs 168 * which must be 16-byte aligned. Because of this, for correct 169 * alignment, sigframe must be a multiple of 8-bytes in length, but 170 * not 16-bytes. This will place ucontext_t at a nice 16-byte boundary. 171 */ 172 173 /* LINTED: logical expression always true: op "||" */ 174 ASSERT((sizeof (struct sigframe) % 16) == 8); 175 176 minstacksz = sizeof (struct sigframe) + SA(sizeof (*uc)); 177 if (sip != NULL) 178 minstacksz += SA(sizeof (siginfo_t)); 179 ASSERT((minstacksz & (STACK_ENTRY_ALIGN - 1ul)) == 0); 180 181 /* 182 * Figure out whether we will be handling this signal on 183 * an alternate stack specified by the user. Then allocate 184 * and validate the stack requirements for the signal handler 185 * context. on_fault will catch any faults. 186 */ 187 newstack = sigismember(&PTOU(curproc)->u_sigonstack, sig) && 188 !(lwp->lwp_sigaltstack.ss_flags & (SS_ONSTACK|SS_DISABLE)); 189 190 if (newstack) { 191 fp = (caddr_t)(SA((uintptr_t)lwp->lwp_sigaltstack.ss_sp) + 192 SA(lwp->lwp_sigaltstack.ss_size) - STACK_ALIGN); 193 } else { 194 /* 195 * Drop below the 128-byte reserved region of the stack frame 196 * we're interrupting. 197 */ 198 fp = (caddr_t)rp->r_sp - STACK_RESERVE; 199 } 200 201 /* 202 * Force proper stack pointer alignment, even in the face of a 203 * misaligned stack pointer from user-level before the signal. 204 */ 205 fp = (caddr_t)((uintptr_t)fp & ~(STACK_ENTRY_ALIGN - 1ul)); 206 207 /* 208 * Most of the time during normal execution, the stack pointer 209 * is aligned on a STACK_ALIGN (i.e. 16 byte) boundary. However, 210 * (for example) just after a call instruction (which pushes 211 * the return address), the callers stack misaligns until the 212 * 'push %rbp' happens in the callee prolog. So while we should 213 * expect the stack pointer to be always at least STACK_ENTRY_ALIGN 214 * aligned, we should -not- expect it to always be STACK_ALIGN aligned. 215 * We now adjust to ensure that the new sp is aligned to 216 * STACK_ENTRY_ALIGN but not to STACK_ALIGN. 217 */ 218 sp = fp - minstacksz; 219 if (((uintptr_t)sp & (STACK_ALIGN - 1ul)) == 0) { 220 sp -= STACK_ENTRY_ALIGN; 221 minstacksz = fp - sp; 222 } 223 224 /* 225 * Now, make sure the resulting signal frame address is sane 226 */ 227 if (sp >= (caddr_t)USERLIMIT || fp >= (caddr_t)USERLIMIT) { 228 #ifdef DEBUG 229 printf("sendsig: bad signal stack cmd=%s, pid=%d, sig=%d\n", 230 PTOU(p)->u_comm, p->p_pid, sig); 231 printf("sigsp = 0x%p, action = 0x%p, upc = 0x%lx\n", 232 (void *)sp, (void *)hdlr, (uintptr_t)upc); 233 printf("sp above USERLIMIT\n"); 234 #endif 235 return (0); 236 } 237 238 watched = watch_disable_addr((caddr_t)sp, minstacksz, S_WRITE); 239 240 if (on_fault(&ljb)) 241 goto badstack; 242 243 if (sip != NULL) { 244 zoneid_t zoneid; 245 246 fp -= SA(sizeof (siginfo_t)); 247 uzero(fp, sizeof (siginfo_t)); 248 if (SI_FROMUSER(sip) && 249 (zoneid = p->p_zone->zone_id) != GLOBAL_ZONEID && 250 zoneid != sip->si_zoneid) { 251 k_siginfo_t sani_sip = *sip; 252 253 sani_sip.si_pid = p->p_zone->zone_zsched->p_pid; 254 sani_sip.si_uid = 0; 255 sani_sip.si_ctid = -1; 256 sani_sip.si_zoneid = zoneid; 257 copyout_noerr(&sani_sip, fp, sizeof (sani_sip)); 258 } else 259 copyout_noerr(sip, fp, sizeof (*sip)); 260 sip_addr = (siginfo_t *)fp; 261 262 if (sig == SIGPROF && 263 curthread->t_rprof != NULL && 264 curthread->t_rprof->rp_anystate) { 265 /* 266 * We stand on our head to deal with 267 * the real time profiling signal. 268 * Fill in the stuff that doesn't fit 269 * in a normal k_siginfo structure. 270 */ 271 int i = sip->si_nsysarg; 272 273 while (--i >= 0) 274 sulword_noerr( 275 (ulong_t *)&(sip_addr->si_sysarg[i]), 276 (ulong_t)lwp->lwp_arg[i]); 277 copyout_noerr(curthread->t_rprof->rp_state, 278 sip_addr->si_mstate, 279 sizeof (curthread->t_rprof->rp_state)); 280 } 281 } else 282 sip_addr = NULL; 283 284 /* 285 * save the current context on the user stack directly after the 286 * sigframe. Since sigframe is 8-byte-but-not-16-byte aligned, 287 * and since sizeof (struct sigframe) is 24, this guarantees 288 * 16-byte alignment for ucontext_t and its %xmm registers. 289 */ 290 uc = (ucontext_t *)(sp + sizeof (struct sigframe)); 291 tuc = kmem_alloc(sizeof (*tuc), KM_SLEEP); 292 savecontext(tuc, lwp->lwp_sigoldmask); 293 copyout_noerr(tuc, uc, sizeof (*tuc)); 294 kmem_free(tuc, sizeof (*tuc)); 295 tuc = NULL; 296 297 lwp->lwp_oldcontext = (uintptr_t)uc; 298 299 if (newstack) { 300 lwp->lwp_sigaltstack.ss_flags |= SS_ONSTACK; 301 if (lwp->lwp_ustack) 302 copyout_noerr(&lwp->lwp_sigaltstack, 303 (stack_t *)lwp->lwp_ustack, sizeof (stack_t)); 304 } 305 306 /* 307 * Set up signal handler return and stack linkage 308 */ 309 { 310 struct sigframe frame; 311 312 /* 313 * ensure we never return "normally" 314 */ 315 frame.retaddr = (caddr_t)(uintptr_t)-1L; 316 frame.signo = sig; 317 frame.sip = sip_addr; 318 copyout_noerr(&frame, sp, sizeof (frame)); 319 } 320 321 no_fault(); 322 if (watched) 323 watch_enable_addr((caddr_t)sp, minstacksz, S_WRITE); 324 325 /* 326 * Set up user registers for execution of signal handler. 327 */ 328 rp->r_sp = (greg_t)sp; 329 rp->r_pc = (greg_t)hdlr; 330 rp->r_ps = PSL_USER | (rp->r_ps & PS_IOPL); 331 332 rp->r_rdi = sig; 333 rp->r_rsi = (uintptr_t)sip_addr; 334 rp->r_rdx = (uintptr_t)uc; 335 336 if ((rp->r_cs & 0xffff) != UCS_SEL || 337 (rp->r_ss & 0xffff) != UDS_SEL) { 338 /* 339 * Try our best to deliver the signal. 340 */ 341 rp->r_cs = UCS_SEL; 342 rp->r_ss = UDS_SEL; 343 } 344 345 /* 346 * Don't set lwp_eosys here. sendsig() is called via psig() after 347 * lwp_eosys is handled, so setting it here would affect the next 348 * system call. 349 */ 350 return (1); 351 352 badstack: 353 no_fault(); 354 if (watched) 355 watch_enable_addr((caddr_t)sp, minstacksz, S_WRITE); 356 if (tuc) 357 kmem_free(tuc, sizeof (*tuc)); 358 #ifdef DEBUG 359 printf("sendsig: bad signal stack cmd=%s, pid=%d, sig=%d\n", 360 PTOU(p)->u_comm, p->p_pid, sig); 361 printf("on fault, sigsp = 0x%p, action = 0x%p, upc = 0x%lx\n", 362 (void *)sp, (void *)hdlr, (uintptr_t)upc); 363 #endif 364 return (0); 365 } 366 367 #ifdef _SYSCALL32_IMPL 368 369 /* 370 * An i386 SVR4/ABI signal frame looks like this on the stack: 371 * 372 * old %esp: 373 * <a siginfo32_t [optional]> 374 * <a ucontext32_t> 375 * <pointer to that ucontext32_t> 376 * <pointer to that siginfo32_t> 377 * <signo> 378 * new %esp: <return address (deliberately invalid)> 379 */ 380 struct sigframe32 { 381 caddr32_t retaddr; 382 uint32_t signo; 383 caddr32_t sip; 384 caddr32_t ucp; 385 }; 386 387 int 388 sendsig32(int sig, k_siginfo_t *sip, void (*hdlr)()) 389 { 390 volatile int minstacksz; 391 int newstack; 392 label_t ljb; 393 volatile caddr_t sp; 394 caddr_t fp; 395 volatile struct regs *rp; 396 volatile greg_t upc; 397 volatile proc_t *p = ttoproc(curthread); 398 klwp_t *lwp = ttolwp(curthread); 399 ucontext32_t *volatile tuc = NULL; 400 ucontext32_t *uc; 401 siginfo32_t *sip_addr; 402 volatile int watched; 403 404 rp = lwptoregs(lwp); 405 upc = rp->r_pc; 406 407 minstacksz = SA32(sizeof (struct sigframe32)) + SA32(sizeof (*uc)); 408 if (sip != NULL) 409 minstacksz += SA32(sizeof (siginfo32_t)); 410 ASSERT((minstacksz & (STACK_ALIGN32 - 1)) == 0); 411 412 /* 413 * Figure out whether we will be handling this signal on 414 * an alternate stack specified by the user. Then allocate 415 * and validate the stack requirements for the signal handler 416 * context. on_fault will catch any faults. 417 */ 418 newstack = sigismember(&PTOU(curproc)->u_sigonstack, sig) && 419 !(lwp->lwp_sigaltstack.ss_flags & (SS_ONSTACK|SS_DISABLE)); 420 421 if (newstack) { 422 fp = (caddr_t)(SA32((uintptr_t)lwp->lwp_sigaltstack.ss_sp) + 423 SA32(lwp->lwp_sigaltstack.ss_size) - STACK_ALIGN32); 424 } else if ((rp->r_ss & 0xffff) != UDS_SEL) { 425 user_desc_t *ldt; 426 /* 427 * If the stack segment selector is -not- pointing at 428 * the UDS_SEL descriptor and we have an LDT entry for 429 * it instead, add the base address to find the effective va. 430 */ 431 if ((ldt = p->p_ldt) != NULL) 432 fp = (caddr_t)rp->r_sp + 433 USEGD_GETBASE(&ldt[SELTOIDX(rp->r_ss)]); 434 else 435 fp = (caddr_t)rp->r_sp; 436 } else 437 fp = (caddr_t)rp->r_sp; 438 439 /* 440 * Force proper stack pointer alignment, even in the face of a 441 * misaligned stack pointer from user-level before the signal. 442 * Don't use the SA32() macro because that rounds up, not down. 443 */ 444 fp = (caddr_t)((uintptr_t)fp & ~(STACK_ALIGN32 - 1)); 445 sp = fp - minstacksz; 446 447 /* 448 * Make sure lwp hasn't trashed its stack 449 */ 450 if (sp >= (caddr_t)(uintptr_t)USERLIMIT32 || 451 fp >= (caddr_t)(uintptr_t)USERLIMIT32) { 452 #ifdef DEBUG 453 printf("sendsig32: bad signal stack cmd=%s, pid=%d, sig=%d\n", 454 PTOU(p)->u_comm, p->p_pid, sig); 455 printf("sigsp = 0x%p, action = 0x%p, upc = 0x%lx\n", 456 (void *)sp, (void *)hdlr, (uintptr_t)upc); 457 printf("sp above USERLIMIT\n"); 458 #endif 459 return (0); 460 } 461 462 watched = watch_disable_addr((caddr_t)sp, minstacksz, S_WRITE); 463 464 if (on_fault(&ljb)) 465 goto badstack; 466 467 if (sip != NULL) { 468 siginfo32_t si32; 469 zoneid_t zoneid; 470 471 siginfo_kto32(sip, &si32); 472 if (SI_FROMUSER(sip) && 473 (zoneid = p->p_zone->zone_id) != GLOBAL_ZONEID && 474 zoneid != sip->si_zoneid) { 475 si32.si_pid = p->p_zone->zone_zsched->p_pid; 476 si32.si_uid = 0; 477 si32.si_ctid = -1; 478 si32.si_zoneid = zoneid; 479 } 480 fp -= SA32(sizeof (si32)); 481 uzero(fp, sizeof (si32)); 482 copyout_noerr(&si32, fp, sizeof (si32)); 483 sip_addr = (siginfo32_t *)fp; 484 485 if (sig == SIGPROF && 486 curthread->t_rprof != NULL && 487 curthread->t_rprof->rp_anystate) { 488 /* 489 * We stand on our head to deal with 490 * the real-time profiling signal. 491 * Fill in the stuff that doesn't fit 492 * in a normal k_siginfo structure. 493 */ 494 int i = sip->si_nsysarg; 495 496 while (--i >= 0) 497 suword32_noerr(&(sip_addr->si_sysarg[i]), 498 (uint32_t)lwp->lwp_arg[i]); 499 copyout_noerr(curthread->t_rprof->rp_state, 500 sip_addr->si_mstate, 501 sizeof (curthread->t_rprof->rp_state)); 502 } 503 } else 504 sip_addr = NULL; 505 506 /* save the current context on the user stack */ 507 fp -= SA32(sizeof (*tuc)); 508 uc = (ucontext32_t *)fp; 509 tuc = kmem_alloc(sizeof (*tuc), KM_SLEEP); 510 savecontext32(tuc, lwp->lwp_sigoldmask); 511 copyout_noerr(tuc, uc, sizeof (*tuc)); 512 kmem_free(tuc, sizeof (*tuc)); 513 tuc = NULL; 514 515 lwp->lwp_oldcontext = (uintptr_t)uc; 516 517 if (newstack) { 518 lwp->lwp_sigaltstack.ss_flags |= SS_ONSTACK; 519 if (lwp->lwp_ustack) { 520 stack32_t stk32; 521 522 stk32.ss_sp = (caddr32_t)(uintptr_t) 523 lwp->lwp_sigaltstack.ss_sp; 524 stk32.ss_size = (size32_t) 525 lwp->lwp_sigaltstack.ss_size; 526 stk32.ss_flags = (int32_t) 527 lwp->lwp_sigaltstack.ss_flags; 528 copyout_noerr(&stk32, 529 (stack32_t *)lwp->lwp_ustack, sizeof (stk32)); 530 } 531 } 532 533 /* 534 * Set up signal handler arguments 535 */ 536 { 537 struct sigframe32 frame32; 538 539 frame32.sip = (caddr32_t)(uintptr_t)sip_addr; 540 frame32.ucp = (caddr32_t)(uintptr_t)uc; 541 frame32.signo = sig; 542 frame32.retaddr = 0xffffffff; /* never return! */ 543 copyout_noerr(&frame32, sp, sizeof (frame32)); 544 } 545 546 no_fault(); 547 if (watched) 548 watch_enable_addr((caddr_t)sp, minstacksz, S_WRITE); 549 550 rp->r_sp = (greg_t)(uintptr_t)sp; 551 rp->r_pc = (greg_t)(uintptr_t)hdlr; 552 rp->r_ps = PSL_USER | (rp->r_ps & PS_IOPL); 553 554 if ((rp->r_cs & 0xffff) != U32CS_SEL || 555 (rp->r_ss & 0xffff) != UDS_SEL) { 556 /* 557 * Try our best to deliver the signal. 558 */ 559 rp->r_cs = U32CS_SEL; 560 rp->r_ss = UDS_SEL; 561 } 562 563 /* 564 * Don't set lwp_eosys here. sendsig() is called via psig() after 565 * lwp_eosys is handled, so setting it here would affect the next 566 * system call. 567 */ 568 return (1); 569 570 badstack: 571 no_fault(); 572 if (watched) 573 watch_enable_addr((caddr_t)sp, minstacksz, S_WRITE); 574 if (tuc) 575 kmem_free(tuc, sizeof (*tuc)); 576 #ifdef DEBUG 577 printf("sendsig32: bad signal stack cmd=%s pid=%d, sig=%d\n", 578 PTOU(p)->u_comm, p->p_pid, sig); 579 printf("on fault, sigsp = 0x%p, action = 0x%p, upc = 0x%lx\n", 580 (void *)sp, (void *)hdlr, (uintptr_t)upc); 581 #endif 582 return (0); 583 } 584 585 #endif /* _SYSCALL32_IMPL */ 586 587 #elif defined(__i386) 588 589 /* 590 * An i386 SVR4/ABI signal frame looks like this on the stack: 591 * 592 * old %esp: 593 * <a siginfo32_t [optional]> 594 * <a ucontext32_t> 595 * <pointer to that ucontext32_t> 596 * <pointer to that siginfo32_t> 597 * <signo> 598 * new %esp: <return address (deliberately invalid)> 599 */ 600 struct sigframe { 601 void (*retaddr)(); 602 uint_t signo; 603 siginfo_t *sip; 604 ucontext_t *ucp; 605 }; 606 607 int 608 sendsig(int sig, k_siginfo_t *sip, void (*hdlr)()) 609 { 610 volatile int minstacksz; 611 int newstack; 612 label_t ljb; 613 volatile caddr_t sp; 614 caddr_t fp; 615 struct regs *rp; 616 volatile greg_t upc; 617 volatile proc_t *p = ttoproc(curthread); 618 klwp_t *lwp = ttolwp(curthread); 619 ucontext_t *volatile tuc = NULL; 620 ucontext_t *uc; 621 siginfo_t *sip_addr; 622 volatile int watched; 623 624 rp = lwptoregs(lwp); 625 upc = rp->r_pc; 626 627 minstacksz = SA(sizeof (struct sigframe)) + SA(sizeof (*uc)); 628 if (sip != NULL) 629 minstacksz += SA(sizeof (siginfo_t)); 630 ASSERT((minstacksz & (STACK_ALIGN - 1ul)) == 0); 631 632 /* 633 * Figure out whether we will be handling this signal on 634 * an alternate stack specified by the user. Then allocate 635 * and validate the stack requirements for the signal handler 636 * context. on_fault will catch any faults. 637 */ 638 newstack = sigismember(&PTOU(curproc)->u_sigonstack, sig) && 639 !(lwp->lwp_sigaltstack.ss_flags & (SS_ONSTACK|SS_DISABLE)); 640 641 if (newstack) { 642 fp = (caddr_t)(SA((uintptr_t)lwp->lwp_sigaltstack.ss_sp) + 643 SA(lwp->lwp_sigaltstack.ss_size) - STACK_ALIGN); 644 } else if ((rp->r_ss & 0xffff) != UDS_SEL) { 645 user_desc_t *ldt; 646 /* 647 * If the stack segment selector is -not- pointing at 648 * the UDS_SEL descriptor and we have an LDT entry for 649 * it instead, add the base address to find the effective va. 650 */ 651 if ((ldt = p->p_ldt) != NULL) 652 fp = (caddr_t)rp->r_sp + 653 USEGD_GETBASE(&ldt[SELTOIDX(rp->r_ss)]); 654 else 655 fp = (caddr_t)rp->r_sp; 656 } else 657 fp = (caddr_t)rp->r_sp; 658 659 /* 660 * Force proper stack pointer alignment, even in the face of a 661 * misaligned stack pointer from user-level before the signal. 662 * Don't use the SA() macro because that rounds up, not down. 663 */ 664 fp = (caddr_t)((uintptr_t)fp & ~(STACK_ALIGN - 1ul)); 665 sp = fp - minstacksz; 666 667 /* 668 * Make sure lwp hasn't trashed its stack. 669 */ 670 if (sp >= (caddr_t)USERLIMIT || fp >= (caddr_t)USERLIMIT) { 671 #ifdef DEBUG 672 printf("sendsig: bad signal stack cmd=%s, pid=%d, sig=%d\n", 673 PTOU(p)->u_comm, p->p_pid, sig); 674 printf("sigsp = 0x%p, action = 0x%p, upc = 0x%lx\n", 675 (void *)sp, (void *)hdlr, (uintptr_t)upc); 676 printf("sp above USERLIMIT\n"); 677 #endif 678 return (0); 679 } 680 681 watched = watch_disable_addr((caddr_t)sp, minstacksz, S_WRITE); 682 683 if (on_fault(&ljb)) 684 goto badstack; 685 686 if (sip != NULL) { 687 zoneid_t zoneid; 688 689 fp -= SA(sizeof (siginfo_t)); 690 uzero(fp, sizeof (siginfo_t)); 691 if (SI_FROMUSER(sip) && 692 (zoneid = p->p_zone->zone_id) != GLOBAL_ZONEID && 693 zoneid != sip->si_zoneid) { 694 k_siginfo_t sani_sip = *sip; 695 696 sani_sip.si_pid = p->p_zone->zone_zsched->p_pid; 697 sani_sip.si_uid = 0; 698 sani_sip.si_ctid = -1; 699 sani_sip.si_zoneid = zoneid; 700 copyout_noerr(&sani_sip, fp, sizeof (sani_sip)); 701 } else 702 copyout_noerr(sip, fp, sizeof (*sip)); 703 sip_addr = (siginfo_t *)fp; 704 705 if (sig == SIGPROF && 706 curthread->t_rprof != NULL && 707 curthread->t_rprof->rp_anystate) { 708 /* 709 * We stand on our head to deal with 710 * the real time profiling signal. 711 * Fill in the stuff that doesn't fit 712 * in a normal k_siginfo structure. 713 */ 714 int i = sip->si_nsysarg; 715 716 while (--i >= 0) 717 suword32_noerr(&(sip_addr->si_sysarg[i]), 718 (uint32_t)lwp->lwp_arg[i]); 719 copyout_noerr(curthread->t_rprof->rp_state, 720 sip_addr->si_mstate, 721 sizeof (curthread->t_rprof->rp_state)); 722 } 723 } else 724 sip_addr = NULL; 725 726 /* save the current context on the user stack */ 727 fp -= SA(sizeof (*tuc)); 728 uc = (ucontext_t *)fp; 729 tuc = kmem_alloc(sizeof (*tuc), KM_SLEEP); 730 savecontext(tuc, lwp->lwp_sigoldmask); 731 copyout_noerr(tuc, uc, sizeof (*tuc)); 732 kmem_free(tuc, sizeof (*tuc)); 733 tuc = NULL; 734 735 lwp->lwp_oldcontext = (uintptr_t)uc; 736 737 if (newstack) { 738 lwp->lwp_sigaltstack.ss_flags |= SS_ONSTACK; 739 if (lwp->lwp_ustack) 740 copyout_noerr(&lwp->lwp_sigaltstack, 741 (stack_t *)lwp->lwp_ustack, sizeof (stack_t)); 742 } 743 744 /* 745 * Set up signal handler arguments 746 */ 747 { 748 struct sigframe frame; 749 750 frame.sip = sip_addr; 751 frame.ucp = uc; 752 frame.signo = sig; 753 frame.retaddr = (void (*)())0xffffffff; /* never return! */ 754 copyout_noerr(&frame, sp, sizeof (frame)); 755 } 756 757 no_fault(); 758 if (watched) 759 watch_enable_addr((caddr_t)sp, minstacksz, S_WRITE); 760 761 rp->r_sp = (greg_t)sp; 762 rp->r_pc = (greg_t)hdlr; 763 rp->r_ps = PSL_USER | (rp->r_ps & PS_IOPL); 764 765 if ((rp->r_cs & 0xffff) != UCS_SEL || 766 (rp->r_ss & 0xffff) != UDS_SEL) { 767 rp->r_cs = UCS_SEL; 768 rp->r_ss = UDS_SEL; 769 } 770 771 /* 772 * Don't set lwp_eosys here. sendsig() is called via psig() after 773 * lwp_eosys is handled, so setting it here would affect the next 774 * system call. 775 */ 776 return (1); 777 778 badstack: 779 no_fault(); 780 if (watched) 781 watch_enable_addr((caddr_t)sp, minstacksz, S_WRITE); 782 if (tuc) 783 kmem_free(tuc, sizeof (*tuc)); 784 #ifdef DEBUG 785 printf("sendsig: bad signal stack cmd=%s, pid=%d, sig=%d\n", 786 PTOU(p)->u_comm, p->p_pid, sig); 787 printf("on fault, sigsp = 0x%p, action = 0x%p, upc = 0x%lx\n", 788 (void *)sp, (void *)hdlr, (uintptr_t)upc); 789 #endif 790 return (0); 791 } 792 793 #endif /* __i386 */ 794