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