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 no_fault();
292 savecontext(tuc, &lwp->lwp_sigoldmask);
293 if (on_fault(&ljb))
294 goto badstack;
295 copyout_noerr(tuc, uc, sizeof (*tuc));
296 kmem_free(tuc, sizeof (*tuc));
297 tuc = NULL;
298
299 lwp->lwp_oldcontext = (uintptr_t)uc;
300
301 if (newstack) {
302 lwp->lwp_sigaltstack.ss_flags |= SS_ONSTACK;
303 if (lwp->lwp_ustack)
304 copyout_noerr(&lwp->lwp_sigaltstack,
305 (stack_t *)lwp->lwp_ustack, sizeof (stack_t));
306 }
307
308 /*
309 * Set up signal handler return and stack linkage
310 */
311 {
312 struct sigframe frame;
313
314 /*
315 * ensure we never return "normally"
316 */
317 frame.retaddr = (caddr_t)(uintptr_t)-1L;
318 frame.signo = sig;
319 frame.sip = sip_addr;
320 copyout_noerr(&frame, sp, sizeof (frame));
321 }
322
323 no_fault();
324 if (watched)
325 watch_enable_addr((caddr_t)sp, minstacksz, S_WRITE);
326
327 /*
328 * Set up user registers for execution of signal handler.
329 */
330 rp->r_sp = (greg_t)sp;
331 rp->r_pc = (greg_t)hdlr;
332 rp->r_ps = PSL_USER | (rp->r_ps & PS_IOPL);
333
334 rp->r_rdi = sig;
335 rp->r_rsi = (uintptr_t)sip_addr;
336 rp->r_rdx = (uintptr_t)uc;
337
338 if ((rp->r_cs & 0xffff) != UCS_SEL ||
339 (rp->r_ss & 0xffff) != UDS_SEL) {
340 /*
341 * Try our best to deliver the signal.
342 */
343 rp->r_cs = UCS_SEL;
344 rp->r_ss = UDS_SEL;
345 }
346
347 /*
348 * Don't set lwp_eosys here. sendsig() is called via psig() after
349 * lwp_eosys is handled, so setting it here would affect the next
350 * system call.
351 */
352 return (1);
353
354 badstack:
355 no_fault();
356 if (watched)
357 watch_enable_addr((caddr_t)sp, minstacksz, S_WRITE);
358 if (tuc)
359 kmem_free(tuc, sizeof (*tuc));
360 #ifdef DEBUG
361 printf("sendsig: bad signal stack cmd=%s, pid=%d, sig=%d\n",
362 PTOU(p)->u_comm, p->p_pid, sig);
363 printf("on fault, sigsp = 0x%p, action = 0x%p, upc = 0x%lx\n",
364 (void *)sp, (void *)hdlr, (uintptr_t)upc);
365 #endif
366 return (0);
367 }
368
369 #ifdef _SYSCALL32_IMPL
370
371 /*
372 * An i386 SVR4/ABI signal frame looks like this on the stack:
373 *
374 * old %esp:
375 * <a siginfo32_t [optional]>
376 * <a ucontext32_t>
377 * <pointer to that ucontext32_t>
378 * <pointer to that siginfo32_t>
379 * <signo>
380 * new %esp: <return address (deliberately invalid)>
381 */
382 struct sigframe32 {
383 caddr32_t retaddr;
384 uint32_t signo;
385 caddr32_t sip;
386 caddr32_t ucp;
387 };
388
389 int
390 sendsig32(int sig, k_siginfo_t *sip, void (*hdlr)())
391 {
392 volatile int minstacksz;
393 int newstack;
394 label_t ljb;
395 volatile caddr_t sp;
396 caddr_t fp;
397 volatile struct regs *rp;
398 volatile greg_t upc;
399 volatile proc_t *p = ttoproc(curthread);
400 klwp_t *lwp = ttolwp(curthread);
401 ucontext32_t *volatile tuc = NULL;
402 ucontext32_t *uc;
403 siginfo32_t *sip_addr;
404 volatile int watched;
405
406 rp = lwptoregs(lwp);
407 upc = rp->r_pc;
408
409 minstacksz = SA32(sizeof (struct sigframe32)) + SA32(sizeof (*uc));
410 if (sip != NULL)
411 minstacksz += SA32(sizeof (siginfo32_t));
412 ASSERT((minstacksz & (STACK_ALIGN32 - 1)) == 0);
413
414 /*
415 * Figure out whether we will be handling this signal on
416 * an alternate stack specified by the user. Then allocate
417 * and validate the stack requirements for the signal handler
418 * context. on_fault will catch any faults.
419 */
420 newstack = sigismember(&PTOU(curproc)->u_sigonstack, sig) &&
421 !(lwp->lwp_sigaltstack.ss_flags & (SS_ONSTACK|SS_DISABLE));
422
423 if (newstack) {
424 fp = (caddr_t)(SA32((uintptr_t)lwp->lwp_sigaltstack.ss_sp) +
425 SA32(lwp->lwp_sigaltstack.ss_size) - STACK_ALIGN32);
426 } else if ((rp->r_ss & 0xffff) != UDS_SEL) {
427 user_desc_t *ldt;
428 /*
429 * If the stack segment selector is -not- pointing at
430 * the UDS_SEL descriptor and we have an LDT entry for
431 * it instead, add the base address to find the effective va.
432 */
433 if ((ldt = p->p_ldt) != NULL)
434 fp = (caddr_t)rp->r_sp +
435 USEGD_GETBASE(&ldt[SELTOIDX(rp->r_ss)]);
436 else
437 fp = (caddr_t)rp->r_sp;
438 } else
439 fp = (caddr_t)rp->r_sp;
440
441 /*
442 * Force proper stack pointer alignment, even in the face of a
443 * misaligned stack pointer from user-level before the signal.
444 * Don't use the SA32() macro because that rounds up, not down.
445 */
446 fp = (caddr_t)((uintptr_t)fp & ~(STACK_ALIGN32 - 1));
447 sp = fp - minstacksz;
448
449 /*
450 * Make sure lwp hasn't trashed its stack
451 */
452 if (sp >= (caddr_t)(uintptr_t)USERLIMIT32 ||
453 fp >= (caddr_t)(uintptr_t)USERLIMIT32) {
454 #ifdef DEBUG
455 printf("sendsig32: bad signal stack cmd=%s, pid=%d, sig=%d\n",
456 PTOU(p)->u_comm, p->p_pid, sig);
457 printf("sigsp = 0x%p, action = 0x%p, upc = 0x%lx\n",
458 (void *)sp, (void *)hdlr, (uintptr_t)upc);
459 printf("sp above USERLIMIT\n");
460 #endif
461 return (0);
462 }
463
464 watched = watch_disable_addr((caddr_t)sp, minstacksz, S_WRITE);
465
466 if (on_fault(&ljb))
467 goto badstack;
468
469 if (sip != NULL) {
470 siginfo32_t si32;
471 zoneid_t zoneid;
472
473 siginfo_kto32(sip, &si32);
474 if (SI_FROMUSER(sip) &&
475 (zoneid = p->p_zone->zone_id) != GLOBAL_ZONEID &&
476 zoneid != sip->si_zoneid) {
477 si32.si_pid = p->p_zone->zone_zsched->p_pid;
478 si32.si_uid = 0;
479 si32.si_ctid = -1;
480 si32.si_zoneid = zoneid;
481 }
482 fp -= SA32(sizeof (si32));
483 uzero(fp, sizeof (si32));
484 copyout_noerr(&si32, fp, sizeof (si32));
485 sip_addr = (siginfo32_t *)fp;
486
487 if (sig == SIGPROF &&
488 curthread->t_rprof != NULL &&
489 curthread->t_rprof->rp_anystate) {
490 /*
491 * We stand on our head to deal with
492 * the real-time profiling signal.
493 * Fill in the stuff that doesn't fit
494 * in a normal k_siginfo structure.
495 */
496 int i = sip->si_nsysarg;
497
498 while (--i >= 0)
499 suword32_noerr(&(sip_addr->si_sysarg[i]),
500 (uint32_t)lwp->lwp_arg[i]);
501 copyout_noerr(curthread->t_rprof->rp_state,
502 sip_addr->si_mstate,
503 sizeof (curthread->t_rprof->rp_state));
504 }
505 } else
506 sip_addr = NULL;
507
508 /* save the current context on the user stack */
509 fp -= SA32(sizeof (*tuc));
510 uc = (ucontext32_t *)fp;
511 tuc = kmem_alloc(sizeof (*tuc), KM_SLEEP);
512 no_fault();
513 savecontext32(tuc, &lwp->lwp_sigoldmask);
514 if (on_fault(&ljb))
515 goto badstack;
516 copyout_noerr(tuc, uc, sizeof (*tuc));
517 kmem_free(tuc, sizeof (*tuc));
518 tuc = NULL;
519
520 lwp->lwp_oldcontext = (uintptr_t)uc;
521
522 if (newstack) {
523 lwp->lwp_sigaltstack.ss_flags |= SS_ONSTACK;
524 if (lwp->lwp_ustack) {
525 stack32_t stk32;
526
527 stk32.ss_sp = (caddr32_t)(uintptr_t)
528 lwp->lwp_sigaltstack.ss_sp;
529 stk32.ss_size = (size32_t)
530 lwp->lwp_sigaltstack.ss_size;
531 stk32.ss_flags = (int32_t)
532 lwp->lwp_sigaltstack.ss_flags;
533 copyout_noerr(&stk32,
534 (stack32_t *)lwp->lwp_ustack, sizeof (stk32));
535 }
536 }
537
538 /*
539 * Set up signal handler arguments
540 */
541 {
542 struct sigframe32 frame32;
543
544 frame32.sip = (caddr32_t)(uintptr_t)sip_addr;
545 frame32.ucp = (caddr32_t)(uintptr_t)uc;
546 frame32.signo = sig;
547 frame32.retaddr = 0xffffffff; /* never return! */
548 copyout_noerr(&frame32, sp, sizeof (frame32));
549 }
550
551 no_fault();
552 if (watched)
553 watch_enable_addr((caddr_t)sp, minstacksz, S_WRITE);
554
555 rp->r_sp = (greg_t)(uintptr_t)sp;
556 rp->r_pc = (greg_t)(uintptr_t)hdlr;
557 rp->r_ps = PSL_USER | (rp->r_ps & PS_IOPL);
558
559 if ((rp->r_cs & 0xffff) != U32CS_SEL ||
560 (rp->r_ss & 0xffff) != UDS_SEL) {
561 /*
562 * Try our best to deliver the signal.
563 */
564 rp->r_cs = U32CS_SEL;
565 rp->r_ss = UDS_SEL;
566 }
567
568 /*
569 * Don't set lwp_eosys here. sendsig() is called via psig() after
570 * lwp_eosys is handled, so setting it here would affect the next
571 * system call.
572 */
573 return (1);
574
575 badstack:
576 no_fault();
577 if (watched)
578 watch_enable_addr((caddr_t)sp, minstacksz, S_WRITE);
579 if (tuc)
580 kmem_free(tuc, sizeof (*tuc));
581 #ifdef DEBUG
582 printf("sendsig32: bad signal stack cmd=%s pid=%d, sig=%d\n",
583 PTOU(p)->u_comm, p->p_pid, sig);
584 printf("on fault, sigsp = 0x%p, action = 0x%p, upc = 0x%lx\n",
585 (void *)sp, (void *)hdlr, (uintptr_t)upc);
586 #endif
587 return (0);
588 }
589
590 #endif /* _SYSCALL32_IMPL */
591
592 #elif defined(__i386)
593
594 /*
595 * An i386 SVR4/ABI signal frame looks like this on the stack:
596 *
597 * old %esp:
598 * <a siginfo32_t [optional]>
599 * <a ucontext32_t>
600 * <pointer to that ucontext32_t>
601 * <pointer to that siginfo32_t>
602 * <signo>
603 * new %esp: <return address (deliberately invalid)>
604 */
605 struct sigframe {
606 void (*retaddr)();
607 uint_t signo;
608 siginfo_t *sip;
609 ucontext_t *ucp;
610 };
611
612 int
613 sendsig(int sig, k_siginfo_t *sip, void (*hdlr)())
614 {
615 volatile int minstacksz;
616 int newstack;
617 label_t ljb;
618 volatile caddr_t sp;
619 caddr_t fp;
620 struct regs *rp;
621 volatile greg_t upc;
622 volatile proc_t *p = ttoproc(curthread);
623 klwp_t *lwp = ttolwp(curthread);
624 ucontext_t *volatile tuc = NULL;
625 ucontext_t *uc;
626 siginfo_t *sip_addr;
627 volatile int watched;
628
629 rp = lwptoregs(lwp);
630 upc = rp->r_pc;
631
632 minstacksz = SA(sizeof (struct sigframe)) + SA(sizeof (*uc));
633 if (sip != NULL)
634 minstacksz += SA(sizeof (siginfo_t));
635 ASSERT((minstacksz & (STACK_ALIGN - 1ul)) == 0);
636
637 /*
638 * Figure out whether we will be handling this signal on
639 * an alternate stack specified by the user. Then allocate
640 * and validate the stack requirements for the signal handler
641 * context. on_fault will catch any faults.
642 */
643 newstack = sigismember(&PTOU(curproc)->u_sigonstack, sig) &&
644 !(lwp->lwp_sigaltstack.ss_flags & (SS_ONSTACK|SS_DISABLE));
645
646 if (newstack) {
647 fp = (caddr_t)(SA((uintptr_t)lwp->lwp_sigaltstack.ss_sp) +
648 SA(lwp->lwp_sigaltstack.ss_size) - STACK_ALIGN);
649 } else if ((rp->r_ss & 0xffff) != UDS_SEL) {
650 user_desc_t *ldt;
651 /*
652 * If the stack segment selector is -not- pointing at
653 * the UDS_SEL descriptor and we have an LDT entry for
654 * it instead, add the base address to find the effective va.
655 */
656 if ((ldt = p->p_ldt) != NULL)
657 fp = (caddr_t)rp->r_sp +
658 USEGD_GETBASE(&ldt[SELTOIDX(rp->r_ss)]);
659 else
660 fp = (caddr_t)rp->r_sp;
661 } else
662 fp = (caddr_t)rp->r_sp;
663
664 /*
665 * Force proper stack pointer alignment, even in the face of a
666 * misaligned stack pointer from user-level before the signal.
667 * Don't use the SA() macro because that rounds up, not down.
668 */
669 fp = (caddr_t)((uintptr_t)fp & ~(STACK_ALIGN - 1ul));
670 sp = fp - minstacksz;
671
672 /*
673 * Make sure lwp hasn't trashed its stack.
674 */
675 if (sp >= (caddr_t)USERLIMIT || fp >= (caddr_t)USERLIMIT) {
676 #ifdef DEBUG
677 printf("sendsig: bad signal stack cmd=%s, pid=%d, sig=%d\n",
678 PTOU(p)->u_comm, p->p_pid, sig);
679 printf("sigsp = 0x%p, action = 0x%p, upc = 0x%lx\n",
680 (void *)sp, (void *)hdlr, (uintptr_t)upc);
681 printf("sp above USERLIMIT\n");
682 #endif
683 return (0);
684 }
685
686 watched = watch_disable_addr((caddr_t)sp, minstacksz, S_WRITE);
687
688 if (on_fault(&ljb))
689 goto badstack;
690
691 if (sip != NULL) {
692 zoneid_t zoneid;
693
694 fp -= SA(sizeof (siginfo_t));
695 uzero(fp, sizeof (siginfo_t));
696 if (SI_FROMUSER(sip) &&
697 (zoneid = p->p_zone->zone_id) != GLOBAL_ZONEID &&
698 zoneid != sip->si_zoneid) {
699 k_siginfo_t sani_sip = *sip;
700
701 sani_sip.si_pid = p->p_zone->zone_zsched->p_pid;
702 sani_sip.si_uid = 0;
703 sani_sip.si_ctid = -1;
704 sani_sip.si_zoneid = zoneid;
705 copyout_noerr(&sani_sip, fp, sizeof (sani_sip));
706 } else
707 copyout_noerr(sip, fp, sizeof (*sip));
708 sip_addr = (siginfo_t *)fp;
709
710 if (sig == SIGPROF &&
711 curthread->t_rprof != NULL &&
712 curthread->t_rprof->rp_anystate) {
713 /*
714 * We stand on our head to deal with
715 * the real time profiling signal.
716 * Fill in the stuff that doesn't fit
717 * in a normal k_siginfo structure.
718 */
719 int i = sip->si_nsysarg;
720
721 while (--i >= 0)
722 suword32_noerr(&(sip_addr->si_sysarg[i]),
723 (uint32_t)lwp->lwp_arg[i]);
724 copyout_noerr(curthread->t_rprof->rp_state,
725 sip_addr->si_mstate,
726 sizeof (curthread->t_rprof->rp_state));
727 }
728 } else
729 sip_addr = NULL;
730
731 /* save the current context on the user stack */
732 fp -= SA(sizeof (*tuc));
733 uc = (ucontext_t *)fp;
734 tuc = kmem_alloc(sizeof (*tuc), KM_SLEEP);
735 savecontext(tuc, &lwp->lwp_sigoldmask);
736 copyout_noerr(tuc, uc, sizeof (*tuc));
737 kmem_free(tuc, sizeof (*tuc));
738 tuc = NULL;
739
740 lwp->lwp_oldcontext = (uintptr_t)uc;
741
742 if (newstack) {
743 lwp->lwp_sigaltstack.ss_flags |= SS_ONSTACK;
744 if (lwp->lwp_ustack)
745 copyout_noerr(&lwp->lwp_sigaltstack,
746 (stack_t *)lwp->lwp_ustack, sizeof (stack_t));
747 }
748
749 /*
750 * Set up signal handler arguments
751 */
752 {
753 struct sigframe frame;
754
755 frame.sip = sip_addr;
756 frame.ucp = uc;
757 frame.signo = sig;
758 frame.retaddr = (void (*)())0xffffffff; /* never return! */
759 copyout_noerr(&frame, sp, sizeof (frame));
760 }
761
762 no_fault();
763 if (watched)
764 watch_enable_addr((caddr_t)sp, minstacksz, S_WRITE);
765
766 rp->r_sp = (greg_t)sp;
767 rp->r_pc = (greg_t)hdlr;
768 rp->r_ps = PSL_USER | (rp->r_ps & PS_IOPL);
769
770 if ((rp->r_cs & 0xffff) != UCS_SEL ||
771 (rp->r_ss & 0xffff) != UDS_SEL) {
772 rp->r_cs = UCS_SEL;
773 rp->r_ss = UDS_SEL;
774 }
775
776 /*
777 * Don't set lwp_eosys here. sendsig() is called via psig() after
778 * lwp_eosys is handled, so setting it here would affect the next
779 * system call.
780 */
781 return (1);
782
783 badstack:
784 no_fault();
785 if (watched)
786 watch_enable_addr((caddr_t)sp, minstacksz, S_WRITE);
787 if (tuc)
788 kmem_free(tuc, sizeof (*tuc));
789 #ifdef DEBUG
790 printf("sendsig: bad signal stack cmd=%s, pid=%d, sig=%d\n",
791 PTOU(p)->u_comm, p->p_pid, sig);
792 printf("on fault, sigsp = 0x%p, action = 0x%p, upc = 0x%lx\n",
793 (void *)sp, (void *)hdlr, (uintptr_t)upc);
794 #endif
795 return (0);
796 }
797
798 #endif /* __i386 */