1 /*-
2 * Copyright (c) 1998 Mark Newton
3 * Copyright (c) 1994 Christos Zoulas
4 * All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 * 3. The name of the author may not be used to endorse or promote products
15 * derived from this software without specific prior written permission
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27 */
28
29 #include <sys/cdefs.h>
30 __FBSDID("$FreeBSD: stable/9/sys/i386/svr4/svr4_machdep.c 177145 2008-03-13 10:54:38Z kib $");
31
32 #include <sys/types.h>
33 #include <sys/param.h>
34 #include <sys/systm.h>
35 #include <sys/exec.h>
36 #include <sys/filedesc.h>
37 #include <sys/lock.h>
38 #include <sys/mutex.h>
39 #include <sys/proc.h>
40 #include <sys/signal.h>
41 #include <sys/signalvar.h>
42
43 #include <machine/cpu.h>
44 #include <machine/cpufunc.h>
45 #include <machine/psl.h>
46 #include <machine/reg.h>
47 #include <machine/specialreg.h>
48 #include <machine/sysarch.h>
49 #include <machine/vm86.h>
50 #include <machine/vmparam.h>
51
52 #include <vm/vm.h>
53 #include <vm/pmap.h>
54
55 #include <compat/svr4/svr4.h>
56 #include <compat/svr4/svr4_types.h>
57 #include <compat/svr4/svr4_signal.h>
58 #include <i386/svr4/svr4_machdep.h>
59 #include <compat/svr4/svr4_ucontext.h>
60 #include <compat/svr4/svr4_proto.h>
61 #include <compat/svr4/svr4_util.h>
62
63 #undef sigcode
64 #undef szsigcode
65
66 extern int svr4_szsigcode;
67 extern char svr4_sigcode[];
68 extern int _udatasel, _ucodesel;
69
70 static void svr4_getsiginfo(union svr4_siginfo *, int, u_long, caddr_t);
71
72 #if !defined(__NetBSD__)
73 /* taken from /sys/arch/i386/include/psl.h on NetBSD-1.3 */
74 # define PSL_MBZ 0xffc08028
75 # define PSL_USERSTATIC (PSL_USER | PSL_MBZ | PSL_IOPL | PSL_NT | PSL_VM | PSL_VIF | PSL_VIP)
76 # define USERMODE(c, f) (ISPL(c) == SEL_UPL)
77 #endif
78
79 #if defined(__NetBSD__)
80 void
svr4_setregs(td,epp,stack)81 svr4_setregs(td, epp, stack)
82 struct thread *td;
83 struct exec_package *epp;
84 u_long stack;
85 {
86 register struct pcb *pcb = td->td_pcb;
87
88 pcb->pcb_savefpu.sv_env.en_cw = __SVR4_NPXCW__;
89 setregs(td, epp, stack, 0UL);
90 }
91 #endif /* __NetBSD__ */
92
93 void
svr4_getcontext(td,uc,mask,oonstack)94 svr4_getcontext(td, uc, mask, oonstack)
95 struct thread *td;
96 struct svr4_ucontext *uc;
97 sigset_t *mask;
98 int oonstack;
99 {
100 struct proc *p = td->td_proc;
101 struct trapframe *tf = td->td_frame;
102 svr4_greg_t *r = uc->uc_mcontext.greg;
103 struct svr4_sigaltstack *s = &uc->uc_stack;
104 #if defined(DONE_MORE_SIGALTSTACK_WORK)
105 struct sigacts *psp;
106 struct sigaltstack *sf;
107 #endif
108
109 PROC_LOCK(p);
110 #if defined(DONE_MORE_SIGALTSTACK_WORK)
111 psp = p->p_sigacts;
112 sf = &p->p_sigstk;
113 #endif
114
115 memset(uc, 0, sizeof(struct svr4_ucontext));
116
117 uc->uc_link = p->p_emuldata;
118 /*
119 * Set the general purpose registers
120 */
121 #ifdef VM86
122 if (tf->tf_eflags & PSL_VM) {
123 r[SVR4_X86_GS] = tf->tf_vm86_gs;
124 r[SVR4_X86_FS] = tf->tf_vm86_fs;
125 r[SVR4_X86_ES] = tf->tf_vm86_es;
126 r[SVR4_X86_DS] = tf->tf_vm86_ds;
127 r[SVR4_X86_EFL] = get_vflags(td);
128 } else
129 #endif
130 {
131 #if defined(__NetBSD__)
132 __asm("movl %%gs,%w0" : "=r" (r[SVR4_X86_GS]));
133 __asm("movl %%fs,%w0" : "=r" (r[SVR4_X86_FS]));
134 #else
135 r[SVR4_X86_GS] = rgs();
136 r[SVR4_X86_FS] = tf->tf_fs;
137 #endif
138 r[SVR4_X86_ES] = tf->tf_es;
139 r[SVR4_X86_DS] = tf->tf_ds;
140 r[SVR4_X86_EFL] = tf->tf_eflags;
141 }
142 r[SVR4_X86_EDI] = tf->tf_edi;
143 r[SVR4_X86_ESI] = tf->tf_esi;
144 r[SVR4_X86_EBP] = tf->tf_ebp;
145 r[SVR4_X86_ESP] = tf->tf_esp;
146 r[SVR4_X86_EBX] = tf->tf_ebx;
147 r[SVR4_X86_EDX] = tf->tf_edx;
148 r[SVR4_X86_ECX] = tf->tf_ecx;
149 r[SVR4_X86_EAX] = tf->tf_eax;
150 r[SVR4_X86_TRAPNO] = tf->tf_trapno;
151 r[SVR4_X86_ERR] = tf->tf_err;
152 r[SVR4_X86_EIP] = tf->tf_eip;
153 r[SVR4_X86_CS] = tf->tf_cs;
154 r[SVR4_X86_UESP] = 0;
155 r[SVR4_X86_SS] = tf->tf_ss;
156
157 /*
158 * Set the signal stack
159 */
160 #if defined(DONE_MORE_SIGALTSTACK_WORK)
161 bsd_to_svr4_sigaltstack(sf, s);
162 #else
163 s->ss_sp = (void *)(((u_long) tf->tf_esp) & ~(16384 - 1));
164 s->ss_size = 16384;
165 s->ss_flags = 0;
166 #endif
167 PROC_UNLOCK(p);
168
169 /*
170 * Set the signal mask
171 */
172 bsd_to_svr4_sigset(mask, &uc->uc_sigmask);
173
174 /*
175 * Set the flags
176 */
177 uc->uc_flags = SVR4_UC_SIGMASK|SVR4_UC_CPU|SVR4_UC_STACK;
178 }
179
180
181 /*
182 * Set to ucontext specified. Reset signal mask and
183 * stack state from context.
184 * Return to previous pc and psl as specified by
185 * context left by sendsig. Check carefully to
186 * make sure that the user has not modified the
187 * psl to gain improper privileges or to cause
188 * a machine fault.
189 */
190 int
svr4_setcontext(td,uc)191 svr4_setcontext(td, uc)
192 struct thread *td;
193 struct svr4_ucontext *uc;
194 {
195 #if defined(DONE_MORE_SIGALTSTACK_WORK)
196 struct sigacts *psp;
197 #endif
198 struct proc *p = td->td_proc;
199 register struct trapframe *tf;
200 svr4_greg_t *r = uc->uc_mcontext.greg;
201 struct svr4_sigaltstack *s = &uc->uc_stack;
202 struct sigaltstack *sf;
203 sigset_t mask;
204
205 PROC_LOCK(p);
206 #if defined(DONE_MORE_SIGALTSTACK_WORK)
207 psp = p->p_sigacts;
208 #endif
209 sf = &td->td_sigstk;
210
211 /*
212 * XXX:
213 * Should we check the value of flags to determine what to restore?
214 * What to do with uc_link?
215 * What to do with floating point stuff?
216 * Should we bother with the rest of the registers that we
217 * set to 0 right now?
218 */
219
220 if ((uc->uc_flags & SVR4_UC_CPU) == 0) {
221 PROC_UNLOCK(p);
222 return 0;
223 }
224
225 DPRINTF(("svr4_setcontext(%d)\n", p->p_pid));
226
227 tf = td->td_frame;
228
229 /*
230 * Restore register context.
231 */
232 #ifdef VM86
233 #warning "VM86 doesn't work yet, please don't try to use it."
234 if (r[SVR4_X86_EFL] & PSL_VM) {
235 tf->tf_vm86_gs = r[SVR4_X86_GS];
236 tf->tf_vm86_fs = r[SVR4_X86_FS];
237 tf->tf_vm86_es = r[SVR4_X86_ES];
238 tf->tf_vm86_ds = r[SVR4_X86_DS];
239 set_vflags(td, r[SVR4_X86_EFL]);
240 } else
241 #endif
242 {
243 /*
244 * Check for security violations. If we're returning to
245 * protected mode, the CPU will validate the segment registers
246 * automatically and generate a trap on violations. We handle
247 * the trap, rather than doing all of the checking here.
248 */
249 if (((r[SVR4_X86_EFL] ^ tf->tf_eflags) & PSL_USERSTATIC) != 0 ||
250 !USERMODE(r[SVR4_X86_CS], r[SVR4_X86_EFL])) {
251 PROC_UNLOCK(p);
252 return (EINVAL);
253 }
254
255 #if defined(__NetBSD__)
256 /* %fs and %gs were restored by the trampoline. */
257 #else
258 /* %gs was restored by the trampoline. */
259 tf->tf_fs = r[SVR4_X86_FS];
260 #endif
261 tf->tf_es = r[SVR4_X86_ES];
262 tf->tf_ds = r[SVR4_X86_DS];
263 tf->tf_eflags = r[SVR4_X86_EFL];
264 }
265 tf->tf_edi = r[SVR4_X86_EDI];
266 tf->tf_esi = r[SVR4_X86_ESI];
267 tf->tf_ebp = r[SVR4_X86_EBP];
268 tf->tf_ebx = r[SVR4_X86_EBX];
269 tf->tf_edx = r[SVR4_X86_EDX];
270 tf->tf_ecx = r[SVR4_X86_ECX];
271 tf->tf_eax = r[SVR4_X86_EAX];
272 tf->tf_trapno = r[SVR4_X86_TRAPNO];
273 tf->tf_err = r[SVR4_X86_ERR];
274 tf->tf_eip = r[SVR4_X86_EIP];
275 tf->tf_cs = r[SVR4_X86_CS];
276 tf->tf_ss = r[SVR4_X86_SS];
277 tf->tf_esp = r[SVR4_X86_ESP];
278
279 p->p_emuldata = uc->uc_link;
280 /*
281 * restore signal stack
282 */
283 if (uc->uc_flags & SVR4_UC_STACK) {
284 svr4_to_bsd_sigaltstack(s, sf);
285 }
286
287 /*
288 * restore signal mask
289 */
290 if (uc->uc_flags & SVR4_UC_SIGMASK) {
291 #if defined(DEBUG_SVR4)
292 {
293 int i;
294 for (i = 0; i < 4; i++)
295 DPRINTF(("\tuc_sigmask[%d] = %lx\n", i,
296 uc->uc_sigmask.bits[i]));
297 }
298 #endif
299 svr4_to_bsd_sigset(&uc->uc_sigmask, &mask);
300 SIG_CANTMASK(mask);
301 td->td_sigmask = mask;
302 signotify(td);
303 }
304 PROC_UNLOCK(p);
305
306 return 0; /*EJUSTRETURN;*/
307 }
308
309
310 static void
svr4_getsiginfo(si,sig,code,addr)311 svr4_getsiginfo(si, sig, code, addr)
312 union svr4_siginfo *si;
313 int sig;
314 u_long code;
315 caddr_t addr;
316 {
317 si->svr4_si_signo = bsd_to_svr4_sig[sig];
318 si->svr4_si_errno = 0;
319 si->svr4_si_addr = addr;
320
321 switch (code) {
322 case T_PRIVINFLT:
323 si->svr4_si_code = SVR4_ILL_PRVOPC;
324 si->svr4_si_trap = SVR4_T_PRIVINFLT;
325 break;
326
327 case T_BPTFLT:
328 si->svr4_si_code = SVR4_TRAP_BRKPT;
329 si->svr4_si_trap = SVR4_T_BPTFLT;
330 break;
331
332 case T_ARITHTRAP:
333 si->svr4_si_code = SVR4_FPE_INTOVF;
334 si->svr4_si_trap = SVR4_T_DIVIDE;
335 break;
336
337 case T_PROTFLT:
338 si->svr4_si_code = SVR4_SEGV_ACCERR;
339 si->svr4_si_trap = SVR4_T_PROTFLT;
340 break;
341
342 case T_TRCTRAP:
343 si->svr4_si_code = SVR4_TRAP_TRACE;
344 si->svr4_si_trap = SVR4_T_TRCTRAP;
345 break;
346
347 case T_PAGEFLT:
348 si->svr4_si_code = SVR4_SEGV_ACCERR;
349 si->svr4_si_trap = SVR4_T_PAGEFLT;
350 break;
351
352 case T_ALIGNFLT:
353 si->svr4_si_code = SVR4_BUS_ADRALN;
354 si->svr4_si_trap = SVR4_T_ALIGNFLT;
355 break;
356
357 case T_DIVIDE:
358 si->svr4_si_code = SVR4_FPE_FLTDIV;
359 si->svr4_si_trap = SVR4_T_DIVIDE;
360 break;
361
362 case T_OFLOW:
363 si->svr4_si_code = SVR4_FPE_FLTOVF;
364 si->svr4_si_trap = SVR4_T_DIVIDE;
365 break;
366
367 case T_BOUND:
368 si->svr4_si_code = SVR4_FPE_FLTSUB;
369 si->svr4_si_trap = SVR4_T_BOUND;
370 break;
371
372 case T_DNA:
373 si->svr4_si_code = SVR4_FPE_FLTINV;
374 si->svr4_si_trap = SVR4_T_DNA;
375 break;
376
377 case T_FPOPFLT:
378 si->svr4_si_code = SVR4_FPE_FLTINV;
379 si->svr4_si_trap = SVR4_T_FPOPFLT;
380 break;
381
382 case T_SEGNPFLT:
383 si->svr4_si_code = SVR4_SEGV_MAPERR;
384 si->svr4_si_trap = SVR4_T_SEGNPFLT;
385 break;
386
387 case T_STKFLT:
388 si->svr4_si_code = SVR4_ILL_BADSTK;
389 si->svr4_si_trap = SVR4_T_STKFLT;
390 break;
391
392 default:
393 si->svr4_si_code = 0;
394 si->svr4_si_trap = 0;
395 #if defined(DEBUG_SVR4)
396 printf("sig %d code %ld\n", sig, code);
397 /* panic("svr4_getsiginfo");*/
398 #endif
399 break;
400 }
401 }
402
403
404 /*
405 * Send an interrupt to process.
406 *
407 * Stack is set up to allow sigcode stored
408 * in u. to call routine. After the handler is
409 * done svr4 will call setcontext for us
410 * with the user context we just set up, and we
411 * will return to the user pc, psl.
412 */
413 void
svr4_sendsig(catcher,ksi,mask)414 svr4_sendsig(catcher, ksi, mask)
415 sig_t catcher;
416 ksiginfo_t *ksi;
417 sigset_t *mask;
418 {
419 register struct thread *td = curthread;
420 struct proc *p = td->td_proc;
421 register struct trapframe *tf;
422 struct svr4_sigframe *fp, frame;
423 struct sigacts *psp;
424 int oonstack;
425 int sig;
426 int code;
427
428 PROC_LOCK_ASSERT(p, MA_OWNED);
429 sig = ksi->ksi_signo;
430 #if defined(DEBUG_SVR4)
431 printf("svr4_sendsig(%d)\n", sig);
432 #endif
433 code = ksi->ksi_trapno; /* use trap No. */
434 psp = p->p_sigacts;
435 mtx_assert(&psp->ps_mtx, MA_OWNED);
436
437 tf = td->td_frame;
438 oonstack = sigonstack(tf->tf_esp);
439
440 /*
441 * Allocate space for the signal handler context.
442 */
443 if ((td->td_pflags & TDP_ALTSTACK) && !oonstack &&
444 SIGISMEMBER(psp->ps_sigonstack, sig)) {
445 fp = (struct svr4_sigframe *)(td->td_sigstk.ss_sp +
446 td->td_sigstk.ss_size - sizeof(struct svr4_sigframe));
447 td->td_sigstk.ss_flags |= SS_ONSTACK;
448 } else {
449 fp = (struct svr4_sigframe *)tf->tf_esp - 1;
450 }
451 mtx_unlock(&psp->ps_mtx);
452 PROC_UNLOCK(p);
453
454 /*
455 * Build the argument list for the signal handler.
456 * Notes:
457 * - we always build the whole argument list, even when we
458 * don't need to [when SA_SIGINFO is not set, we don't need
459 * to pass all sf_si and sf_uc]
460 * - we don't pass the correct signal address [we need to
461 * modify many kernel files to enable that]
462 */
463
464 svr4_getcontext(td, &frame.sf_uc, mask, oonstack);
465 #if defined(DEBUG_SVR4)
466 printf("obtained ucontext\n");
467 #endif
468 svr4_getsiginfo(&frame.sf_si, sig, code, (caddr_t) tf->tf_eip);
469 #if defined(DEBUG_SVR4)
470 printf("obtained siginfo\n");
471 #endif
472 frame.sf_signum = frame.sf_si.svr4_si_signo;
473 frame.sf_sip = &fp->sf_si;
474 frame.sf_ucp = &fp->sf_uc;
475 frame.sf_handler = catcher;
476 #if defined(DEBUG_SVR4)
477 printf("sig = %d, sip %p, ucp = %p, handler = %p\n",
478 frame.sf_signum, frame.sf_sip, frame.sf_ucp, frame.sf_handler);
479 #endif
480
481 if (copyout(&frame, fp, sizeof(frame)) != 0) {
482 /*
483 * Process has trashed its stack; give it an illegal
484 * instruction to halt it in its tracks.
485 */
486 PROC_LOCK(p);
487 sigexit(td, SIGILL);
488 /* NOTREACHED */
489 }
490 #if defined(__NetBSD__)
491 /*
492 * Build context to run handler in.
493 */
494 tf->tf_es = GSEL(GUSERLDT_SEL, SEL_UPL);
495 tf->tf_ds = GSEL(GUSERLDT_SEL, SEL_UPL);
496 tf->tf_eip = (int)(((char *)PS_STRINGS) -
497 svr4_szsigcode);
498 tf->tf_cs = GSEL(GUSERLDT_SEL, SEL_UPL);
499
500 tf->tf_eflags &= ~(PSL_T|PSL_VM|PSL_AC|PSL_D);
501 tf->tf_esp = (int)fp;
502 tf->tf_ss = GSEL(GUSERLDT_SEL, SEL_UPL);
503 #else
504 tf->tf_esp = (int)fp;
505 tf->tf_eip = (int)(((char *)PS_STRINGS) - *(p->p_sysent->sv_szsigcode));
506 tf->tf_eflags &= ~(PSL_T | PSL_D);
507 tf->tf_cs = _ucodesel;
508 tf->tf_ds = _udatasel;
509 tf->tf_es = _udatasel;
510 tf->tf_fs = _udatasel;
511 load_gs(_udatasel);
512 tf->tf_ss = _udatasel;
513 PROC_LOCK(p);
514 mtx_lock(&psp->ps_mtx);
515 #endif
516 }
517
518
519
520 int
svr4_sys_sysarch(td,v)521 svr4_sys_sysarch(td, v)
522 struct thread *td;
523 struct svr4_sys_sysarch_args *v;
524 {
525 struct svr4_sys_sysarch_args *uap = v;
526 #if 0 /* USER_LDT */
527 #if defined(__NetBSD__)
528 caddr_t sg = stackgap_init(p->p_emul);
529 #else
530 caddr_t sg = stackgap_init();
531 #endif
532 int error;
533 #endif
534
535 switch (uap->op) {
536 case SVR4_SYSARCH_FPHW:
537 return 0;
538
539 case SVR4_SYSARCH_DSCR:
540 #if 0 /* USER_LDT */
541 #warning "USER_LDT doesn't work - are you sure you want this?"
542 {
543 struct i386_set_ldt_args sa, *sap;
544 struct sys_sysarch_args ua;
545
546 struct svr4_ssd ssd;
547 union descriptor bsd;
548
549 if ((error = copyin(uap->a1, &ssd,
550 sizeof(ssd))) != 0) {
551 printf("Cannot copy arg1\n");
552 return error;
553 }
554
555 printf("s=%x, b=%x, l=%x, a1=%x a2=%x\n",
556 ssd.selector, ssd.base, ssd.limit,
557 ssd.access1, ssd.access2);
558
559 /* We can only set ldt's for now. */
560 if (!ISLDT(ssd.selector)) {
561 printf("Not an ldt\n");
562 return EPERM;
563 }
564
565 /* Oh, well we don't cleanup either */
566 if (ssd.access1 == 0)
567 return 0;
568
569 bsd.sd.sd_lobase = ssd.base & 0xffffff;
570 bsd.sd.sd_hibase = (ssd.base >> 24) & 0xff;
571
572 bsd.sd.sd_lolimit = ssd.limit & 0xffff;
573 bsd.sd.sd_hilimit = (ssd.limit >> 16) & 0xf;
574
575 bsd.sd.sd_type = ssd.access1 & 0x1f;
576 bsd.sd.sd_dpl = (ssd.access1 >> 5) & 0x3;
577 bsd.sd.sd_p = (ssd.access1 >> 7) & 0x1;
578
579 bsd.sd.sd_xx = ssd.access2 & 0x3;
580 bsd.sd.sd_def32 = (ssd.access2 >> 2) & 0x1;
581 bsd.sd.sd_gran = (ssd.access2 >> 3)& 0x1;
582
583 sa.start = IDXSEL(ssd.selector);
584 sa.desc = stackgap_alloc(&sg, sizeof(union descriptor));
585 sa.num = 1;
586 sap = stackgap_alloc(&sg,
587 sizeof(struct i386_set_ldt_args));
588
589 if ((error = copyout(&sa, sap, sizeof(sa))) != 0) {
590 printf("Cannot copyout args\n");
591 return error;
592 }
593
594 ua.op = I386_SET_LDT;
595 ua.parms = (char *) sap;
596
597 if ((error = copyout(&bsd, sa.desc, sizeof(bsd))) != 0) {
598 printf("Cannot copyout desc\n");
599 return error;
600 }
601
602 return sys_sysarch(td, &ua, retval);
603 }
604 #endif
605
606 default:
607 printf("svr4_sysarch(%d), a1 %p\n", uap->op,
608 uap->a1);
609 return 0;
610 }
611 }
612