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/10/sys/i386/svr4/svr4_machdep.c 276080 2014-12-22 20:53:45Z jhb $");
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
69 static void svr4_getsiginfo(union svr4_siginfo *, int, u_long, caddr_t);
70
71 #if !defined(__NetBSD__)
72 /* taken from /sys/arch/i386/include/psl.h on NetBSD-1.3 */
73 # define PSL_MBZ 0xffc08028
74 # define PSL_USERSTATIC (PSL_USER | PSL_MBZ | PSL_IOPL | PSL_NT | PSL_VM | PSL_VIF | PSL_VIP)
75 # define USERMODE(c, f) (ISPL(c) == SEL_UPL)
76 #endif
77
78 #if defined(__NetBSD__)
79 void
svr4_setregs(td,epp,stack)80 svr4_setregs(td, epp, stack)
81 struct thread *td;
82 struct exec_package *epp;
83 u_long stack;
84 {
85 register struct pcb *pcb = td->td_pcb;
86
87 pcb->pcb_savefpu.sv_env.en_cw = __SVR4_NPXCW__;
88 setregs(td, epp, stack, 0UL);
89 }
90 #endif /* __NetBSD__ */
91
92 void
svr4_getcontext(td,uc,mask,oonstack)93 svr4_getcontext(td, uc, mask, oonstack)
94 struct thread *td;
95 struct svr4_ucontext *uc;
96 sigset_t *mask;
97 int oonstack;
98 {
99 struct proc *p = td->td_proc;
100 struct trapframe *tf = td->td_frame;
101 svr4_greg_t *r = uc->uc_mcontext.greg;
102 struct svr4_sigaltstack *s = &uc->uc_stack;
103 #if defined(DONE_MORE_SIGALTSTACK_WORK)
104 struct sigacts *psp;
105 struct sigaltstack *sf;
106 #endif
107
108 PROC_LOCK(p);
109 #if defined(DONE_MORE_SIGALTSTACK_WORK)
110 psp = p->p_sigacts;
111 sf = &p->p_sigstk;
112 #endif
113
114 memset(uc, 0, sizeof(struct svr4_ucontext));
115
116 uc->uc_link = p->p_emuldata;
117 /*
118 * Set the general purpose registers
119 */
120 #ifdef VM86
121 if (tf->tf_eflags & PSL_VM) {
122 r[SVR4_X86_GS] = tf->tf_vm86_gs;
123 r[SVR4_X86_FS] = tf->tf_vm86_fs;
124 r[SVR4_X86_ES] = tf->tf_vm86_es;
125 r[SVR4_X86_DS] = tf->tf_vm86_ds;
126 r[SVR4_X86_EFL] = get_vflags(td);
127 } else
128 #endif
129 {
130 #if defined(__NetBSD__)
131 __asm("movl %%gs,%w0" : "=r" (r[SVR4_X86_GS]));
132 __asm("movl %%fs,%w0" : "=r" (r[SVR4_X86_FS]));
133 #else
134 r[SVR4_X86_GS] = rgs();
135 r[SVR4_X86_FS] = tf->tf_fs;
136 #endif
137 r[SVR4_X86_ES] = tf->tf_es;
138 r[SVR4_X86_DS] = tf->tf_ds;
139 r[SVR4_X86_EFL] = tf->tf_eflags;
140 }
141 r[SVR4_X86_EDI] = tf->tf_edi;
142 r[SVR4_X86_ESI] = tf->tf_esi;
143 r[SVR4_X86_EBP] = tf->tf_ebp;
144 r[SVR4_X86_ESP] = tf->tf_esp;
145 r[SVR4_X86_EBX] = tf->tf_ebx;
146 r[SVR4_X86_EDX] = tf->tf_edx;
147 r[SVR4_X86_ECX] = tf->tf_ecx;
148 r[SVR4_X86_EAX] = tf->tf_eax;
149 r[SVR4_X86_TRAPNO] = tf->tf_trapno;
150 r[SVR4_X86_ERR] = tf->tf_err;
151 r[SVR4_X86_EIP] = tf->tf_eip;
152 r[SVR4_X86_CS] = tf->tf_cs;
153 r[SVR4_X86_UESP] = 0;
154 r[SVR4_X86_SS] = tf->tf_ss;
155
156 /*
157 * Set the signal stack
158 */
159 #if defined(DONE_MORE_SIGALTSTACK_WORK)
160 bsd_to_svr4_sigaltstack(sf, s);
161 #else
162 s->ss_sp = (void *)(((u_long) tf->tf_esp) & ~(16384 - 1));
163 s->ss_size = 16384;
164 s->ss_flags = 0;
165 #endif
166 PROC_UNLOCK(p);
167
168 /*
169 * Set the signal mask
170 */
171 bsd_to_svr4_sigset(mask, &uc->uc_sigmask);
172
173 /*
174 * Set the flags
175 */
176 uc->uc_flags = SVR4_UC_SIGMASK|SVR4_UC_CPU|SVR4_UC_STACK;
177 }
178
179
180 /*
181 * Set to ucontext specified. Reset signal mask and
182 * stack state from context.
183 * Return to previous pc and psl as specified by
184 * context left by sendsig. Check carefully to
185 * make sure that the user has not modified the
186 * psl to gain improper privileges or to cause
187 * a machine fault.
188 */
189 int
svr4_setcontext(td,uc)190 svr4_setcontext(td, uc)
191 struct thread *td;
192 struct svr4_ucontext *uc;
193 {
194 #if defined(DONE_MORE_SIGALTSTACK_WORK)
195 struct sigacts *psp;
196 #endif
197 struct proc *p = td->td_proc;
198 register struct trapframe *tf;
199 svr4_greg_t *r = uc->uc_mcontext.greg;
200 struct svr4_sigaltstack *s = &uc->uc_stack;
201 struct sigaltstack *sf;
202 sigset_t mask;
203
204 PROC_LOCK(p);
205 #if defined(DONE_MORE_SIGALTSTACK_WORK)
206 psp = p->p_sigacts;
207 #endif
208 sf = &td->td_sigstk;
209
210 /*
211 * XXX:
212 * Should we check the value of flags to determine what to restore?
213 * What to do with uc_link?
214 * What to do with floating point stuff?
215 * Should we bother with the rest of the registers that we
216 * set to 0 right now?
217 */
218
219 if ((uc->uc_flags & SVR4_UC_CPU) == 0) {
220 PROC_UNLOCK(p);
221 return 0;
222 }
223
224 DPRINTF(("svr4_setcontext(%d)\n", p->p_pid));
225
226 tf = td->td_frame;
227
228 /*
229 * Restore register context.
230 */
231 #ifdef VM86
232 #warning "VM86 doesn't work yet, please don't try to use it."
233 if (r[SVR4_X86_EFL] & PSL_VM) {
234 tf->tf_vm86_gs = r[SVR4_X86_GS];
235 tf->tf_vm86_fs = r[SVR4_X86_FS];
236 tf->tf_vm86_es = r[SVR4_X86_ES];
237 tf->tf_vm86_ds = r[SVR4_X86_DS];
238 set_vflags(td, r[SVR4_X86_EFL]);
239 } else
240 #endif
241 {
242 /*
243 * Check for security violations. If we're returning to
244 * protected mode, the CPU will validate the segment registers
245 * automatically and generate a trap on violations. We handle
246 * the trap, rather than doing all of the checking here.
247 */
248 if (((r[SVR4_X86_EFL] ^ tf->tf_eflags) & PSL_USERSTATIC) != 0 ||
249 !USERMODE(r[SVR4_X86_CS], r[SVR4_X86_EFL])) {
250 PROC_UNLOCK(p);
251 return (EINVAL);
252 }
253
254 #if defined(__NetBSD__)
255 /* %fs and %gs were restored by the trampoline. */
256 #else
257 /* %gs was restored by the trampoline. */
258 tf->tf_fs = r[SVR4_X86_FS];
259 #endif
260 tf->tf_es = r[SVR4_X86_ES];
261 tf->tf_ds = r[SVR4_X86_DS];
262 tf->tf_eflags = r[SVR4_X86_EFL];
263 }
264 tf->tf_edi = r[SVR4_X86_EDI];
265 tf->tf_esi = r[SVR4_X86_ESI];
266 tf->tf_ebp = r[SVR4_X86_EBP];
267 tf->tf_ebx = r[SVR4_X86_EBX];
268 tf->tf_edx = r[SVR4_X86_EDX];
269 tf->tf_ecx = r[SVR4_X86_ECX];
270 tf->tf_eax = r[SVR4_X86_EAX];
271 tf->tf_trapno = r[SVR4_X86_TRAPNO];
272 tf->tf_err = r[SVR4_X86_ERR];
273 tf->tf_eip = r[SVR4_X86_EIP];
274 tf->tf_cs = r[SVR4_X86_CS];
275 tf->tf_ss = r[SVR4_X86_SS];
276 tf->tf_esp = r[SVR4_X86_ESP];
277
278 p->p_emuldata = uc->uc_link;
279 /*
280 * restore signal stack
281 */
282 if (uc->uc_flags & SVR4_UC_STACK) {
283 svr4_to_bsd_sigaltstack(s, sf);
284 }
285
286 /*
287 * restore signal mask
288 */
289 if (uc->uc_flags & SVR4_UC_SIGMASK) {
290 #if defined(DEBUG_SVR4)
291 {
292 int i;
293 for (i = 0; i < 4; i++)
294 DPRINTF(("\tuc_sigmask[%d] = %lx\n", i,
295 uc->uc_sigmask.bits[i]));
296 }
297 #endif
298 svr4_to_bsd_sigset(&uc->uc_sigmask, &mask);
299 SIG_CANTMASK(mask);
300 td->td_sigmask = mask;
301 signotify(td);
302 }
303 PROC_UNLOCK(p);
304
305 return 0; /*EJUSTRETURN;*/
306 }
307
308
309 static void
svr4_getsiginfo(si,sig,code,addr)310 svr4_getsiginfo(si, sig, code, addr)
311 union svr4_siginfo *si;
312 int sig;
313 u_long code;
314 caddr_t addr;
315 {
316 si->svr4_si_signo = bsd_to_svr4_sig[sig];
317 si->svr4_si_errno = 0;
318 si->svr4_si_addr = addr;
319
320 switch (code) {
321 case T_PRIVINFLT:
322 si->svr4_si_code = SVR4_ILL_PRVOPC;
323 si->svr4_si_trap = SVR4_T_PRIVINFLT;
324 break;
325
326 case T_BPTFLT:
327 si->svr4_si_code = SVR4_TRAP_BRKPT;
328 si->svr4_si_trap = SVR4_T_BPTFLT;
329 break;
330
331 case T_ARITHTRAP:
332 si->svr4_si_code = SVR4_FPE_INTOVF;
333 si->svr4_si_trap = SVR4_T_DIVIDE;
334 break;
335
336 case T_PROTFLT:
337 si->svr4_si_code = SVR4_SEGV_ACCERR;
338 si->svr4_si_trap = SVR4_T_PROTFLT;
339 break;
340
341 case T_TRCTRAP:
342 si->svr4_si_code = SVR4_TRAP_TRACE;
343 si->svr4_si_trap = SVR4_T_TRCTRAP;
344 break;
345
346 case T_PAGEFLT:
347 si->svr4_si_code = SVR4_SEGV_ACCERR;
348 si->svr4_si_trap = SVR4_T_PAGEFLT;
349 break;
350
351 case T_ALIGNFLT:
352 si->svr4_si_code = SVR4_BUS_ADRALN;
353 si->svr4_si_trap = SVR4_T_ALIGNFLT;
354 break;
355
356 case T_DIVIDE:
357 si->svr4_si_code = SVR4_FPE_FLTDIV;
358 si->svr4_si_trap = SVR4_T_DIVIDE;
359 break;
360
361 case T_OFLOW:
362 si->svr4_si_code = SVR4_FPE_FLTOVF;
363 si->svr4_si_trap = SVR4_T_DIVIDE;
364 break;
365
366 case T_BOUND:
367 si->svr4_si_code = SVR4_FPE_FLTSUB;
368 si->svr4_si_trap = SVR4_T_BOUND;
369 break;
370
371 case T_DNA:
372 si->svr4_si_code = SVR4_FPE_FLTINV;
373 si->svr4_si_trap = SVR4_T_DNA;
374 break;
375
376 case T_FPOPFLT:
377 si->svr4_si_code = SVR4_FPE_FLTINV;
378 si->svr4_si_trap = SVR4_T_FPOPFLT;
379 break;
380
381 case T_SEGNPFLT:
382 si->svr4_si_code = SVR4_SEGV_MAPERR;
383 si->svr4_si_trap = SVR4_T_SEGNPFLT;
384 break;
385
386 case T_STKFLT:
387 si->svr4_si_code = SVR4_ILL_BADSTK;
388 si->svr4_si_trap = SVR4_T_STKFLT;
389 break;
390
391 default:
392 si->svr4_si_code = 0;
393 si->svr4_si_trap = 0;
394 #if defined(DEBUG_SVR4)
395 printf("sig %d code %ld\n", sig, code);
396 /* panic("svr4_getsiginfo");*/
397 #endif
398 break;
399 }
400 }
401
402
403 /*
404 * Send an interrupt to process.
405 *
406 * Stack is set up to allow sigcode stored
407 * in u. to call routine. After the handler is
408 * done svr4 will call setcontext for us
409 * with the user context we just set up, and we
410 * will return to the user pc, psl.
411 */
412 void
svr4_sendsig(catcher,ksi,mask)413 svr4_sendsig(catcher, ksi, mask)
414 sig_t catcher;
415 ksiginfo_t *ksi;
416 sigset_t *mask;
417 {
418 register struct thread *td = curthread;
419 struct proc *p = td->td_proc;
420 register struct trapframe *tf;
421 struct svr4_sigframe *fp, frame;
422 struct sigacts *psp;
423 int oonstack;
424 int sig;
425 int code;
426
427 PROC_LOCK_ASSERT(p, MA_OWNED);
428 sig = ksi->ksi_signo;
429 #if defined(DEBUG_SVR4)
430 printf("svr4_sendsig(%d)\n", sig);
431 #endif
432 code = ksi->ksi_trapno; /* use trap No. */
433 psp = p->p_sigacts;
434 mtx_assert(&psp->ps_mtx, MA_OWNED);
435
436 tf = td->td_frame;
437 oonstack = sigonstack(tf->tf_esp);
438
439 /*
440 * Allocate space for the signal handler context.
441 */
442 if ((td->td_pflags & TDP_ALTSTACK) && !oonstack &&
443 SIGISMEMBER(psp->ps_sigonstack, sig)) {
444 fp = (struct svr4_sigframe *)(td->td_sigstk.ss_sp +
445 td->td_sigstk.ss_size - sizeof(struct svr4_sigframe));
446 td->td_sigstk.ss_flags |= SS_ONSTACK;
447 } else {
448 fp = (struct svr4_sigframe *)tf->tf_esp - 1;
449 }
450 mtx_unlock(&psp->ps_mtx);
451 PROC_UNLOCK(p);
452
453 /*
454 * Build the argument list for the signal handler.
455 * Notes:
456 * - we always build the whole argument list, even when we
457 * don't need to [when SA_SIGINFO is not set, we don't need
458 * to pass all sf_si and sf_uc]
459 * - we don't pass the correct signal address [we need to
460 * modify many kernel files to enable that]
461 */
462
463 svr4_getcontext(td, &frame.sf_uc, mask, oonstack);
464 #if defined(DEBUG_SVR4)
465 printf("obtained ucontext\n");
466 #endif
467 svr4_getsiginfo(&frame.sf_si, sig, code, (caddr_t) tf->tf_eip);
468 #if defined(DEBUG_SVR4)
469 printf("obtained siginfo\n");
470 #endif
471 frame.sf_signum = frame.sf_si.svr4_si_signo;
472 frame.sf_sip = &fp->sf_si;
473 frame.sf_ucp = &fp->sf_uc;
474 frame.sf_handler = catcher;
475 #if defined(DEBUG_SVR4)
476 printf("sig = %d, sip %p, ucp = %p, handler = %p\n",
477 frame.sf_signum, frame.sf_sip, frame.sf_ucp, frame.sf_handler);
478 #endif
479
480 if (copyout(&frame, fp, sizeof(frame)) != 0) {
481 /*
482 * Process has trashed its stack; give it an illegal
483 * instruction to halt it in its tracks.
484 */
485 PROC_LOCK(p);
486 sigexit(td, SIGILL);
487 /* NOTREACHED */
488 }
489 #if defined(__NetBSD__)
490 /*
491 * Build context to run handler in.
492 */
493 tf->tf_es = GSEL(GUSERLDT_SEL, SEL_UPL);
494 tf->tf_ds = GSEL(GUSERLDT_SEL, SEL_UPL);
495 tf->tf_eip = (int)(((char *)PS_STRINGS) -
496 svr4_szsigcode);
497 tf->tf_cs = GSEL(GUSERLDT_SEL, SEL_UPL);
498
499 tf->tf_eflags &= ~(PSL_T|PSL_VM|PSL_AC|PSL_D);
500 tf->tf_esp = (int)fp;
501 tf->tf_ss = GSEL(GUSERLDT_SEL, SEL_UPL);
502 #else
503 tf->tf_esp = (int)fp;
504 tf->tf_eip = (int)(((char *)PS_STRINGS) - *(p->p_sysent->sv_szsigcode));
505 tf->tf_eflags &= ~(PSL_T | PSL_D);
506 tf->tf_cs = _ucodesel;
507 tf->tf_ds = _udatasel;
508 tf->tf_es = _udatasel;
509 tf->tf_fs = _udatasel;
510 load_gs(_udatasel);
511 tf->tf_ss = _udatasel;
512 PROC_LOCK(p);
513 mtx_lock(&psp->ps_mtx);
514 #endif
515 }
516
517
518
519 int
svr4_sys_sysarch(td,v)520 svr4_sys_sysarch(td, v)
521 struct thread *td;
522 struct svr4_sys_sysarch_args *v;
523 {
524 struct svr4_sys_sysarch_args *uap = v;
525 #if 0 /* USER_LDT */
526 #if defined(__NetBSD__)
527 caddr_t sg = stackgap_init(p->p_emul);
528 #else
529 caddr_t sg = stackgap_init();
530 #endif
531 int error;
532 #endif
533
534 switch (uap->op) {
535 case SVR4_SYSARCH_FPHW:
536 return 0;
537
538 case SVR4_SYSARCH_DSCR:
539 #if 0 /* USER_LDT */
540 #warning "USER_LDT doesn't work - are you sure you want this?"
541 {
542 struct i386_set_ldt_args sa, *sap;
543 struct sys_sysarch_args ua;
544
545 struct svr4_ssd ssd;
546 union descriptor bsd;
547
548 if ((error = copyin(uap->a1, &ssd,
549 sizeof(ssd))) != 0) {
550 printf("Cannot copy arg1\n");
551 return error;
552 }
553
554 printf("s=%x, b=%x, l=%x, a1=%x a2=%x\n",
555 ssd.selector, ssd.base, ssd.limit,
556 ssd.access1, ssd.access2);
557
558 /* We can only set ldt's for now. */
559 if (!ISLDT(ssd.selector)) {
560 printf("Not an ldt\n");
561 return EPERM;
562 }
563
564 /* Oh, well we don't cleanup either */
565 if (ssd.access1 == 0)
566 return 0;
567
568 bsd.sd.sd_lobase = ssd.base & 0xffffff;
569 bsd.sd.sd_hibase = (ssd.base >> 24) & 0xff;
570
571 bsd.sd.sd_lolimit = ssd.limit & 0xffff;
572 bsd.sd.sd_hilimit = (ssd.limit >> 16) & 0xf;
573
574 bsd.sd.sd_type = ssd.access1 & 0x1f;
575 bsd.sd.sd_dpl = (ssd.access1 >> 5) & 0x3;
576 bsd.sd.sd_p = (ssd.access1 >> 7) & 0x1;
577
578 bsd.sd.sd_xx = ssd.access2 & 0x3;
579 bsd.sd.sd_def32 = (ssd.access2 >> 2) & 0x1;
580 bsd.sd.sd_gran = (ssd.access2 >> 3)& 0x1;
581
582 sa.start = IDXSEL(ssd.selector);
583 sa.desc = stackgap_alloc(&sg, sizeof(union descriptor));
584 sa.num = 1;
585 sap = stackgap_alloc(&sg,
586 sizeof(struct i386_set_ldt_args));
587
588 if ((error = copyout(&sa, sap, sizeof(sa))) != 0) {
589 printf("Cannot copyout args\n");
590 return error;
591 }
592
593 ua.op = I386_SET_LDT;
594 ua.parms = (char *) sap;
595
596 if ((error = copyout(&bsd, sa.desc, sizeof(bsd))) != 0) {
597 printf("Cannot copyout desc\n");
598 return error;
599 }
600
601 return sys_sysarch(td, &ua, retval);
602 }
603 #endif
604
605 default:
606 printf("svr4_sysarch(%d), a1 %p\n", uap->op,
607 uap->a1);
608 return 0;
609 }
610 }
611