svr4_machdep.c revision 76166
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 * $FreeBSD: head/sys/i386/svr4/svr4_machdep.c 76166 2001-05-01 08:13:21Z markm $
29 */
30
31#include <sys/types.h>
32#include <sys/param.h>
33#include <sys/systm.h>
34#include <sys/exec.h>
35#include <sys/filedesc.h>
36#include <sys/lock.h>
37#include <sys/mutex.h>
38#include <sys/proc.h>
39#include <sys/signal.h>
40#include <sys/signalvar.h>
41
42#include <machine/cpu.h>
43#include <machine/cpufunc.h>
44#include <machine/psl.h>
45#include <machine/reg.h>
46#include <machine/specialreg.h>
47#include <machine/sysarch.h>
48#include <machine/vm86.h>
49#include <machine/vmparam.h>
50
51#include <vm/vm.h>
52#include <vm/pmap.h>
53
54#include <compat/svr4/svr4.h>
55#include <compat/svr4/svr4_types.h>
56#include <compat/svr4/svr4_signal.h>
57#include <i386/svr4/svr4_machdep.h>
58#include <compat/svr4/svr4_ucontext.h>
59#include <compat/svr4/svr4_proto.h>
60#include <compat/svr4/svr4_util.h>
61
62#undef sigcode
63#undef szsigcode
64
65extern int svr4_szsigcode;
66extern char svr4_sigcode[];
67extern int _udatasel, _ucodesel;
68
69static void svr4_getsiginfo __P((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__)
79void
80svr4_setregs(p, epp, stack)
81	struct proc *p;
82	struct exec_package *epp;
83	u_long stack;
84{
85	register struct pcb *pcb = &p->p_addr->u_pcb;
86
87	pcb->pcb_savefpu.sv_env.en_cw = __SVR4_NPXCW__;
88	setregs(p, epp, stack, 0UL);
89}
90#endif /* __NetBSD__ */
91
92void
93svr4_getcontext(p, uc, mask, oonstack)
94	struct proc *p;
95	struct svr4_ucontext *uc;
96	sigset_t *mask;
97	int oonstack;
98{
99	struct trapframe *tf = p->p_md.md_regs;
100	svr4_greg_t *r = uc->uc_mcontext.greg;
101	struct svr4_sigaltstack *s = &uc->uc_stack;
102#if defined(DONE_MORE_SIGALTSTACK_WORK)
103	struct sigacts *psp;
104	struct sigaltstack *sf;
105#endif
106
107	PROC_LOCK(p);
108#if defined(DONE_MORE_SIGALTSTACK_WORK)
109	psp = p->p_sigacts;
110	sf = &p->p_sigstk;
111#endif
112
113	memset(uc, 0, sizeof(struct svr4_ucontext));
114
115	uc->uc_link = p->p_emuldata;
116	/*
117	 * Set the general purpose registers
118	 */
119#ifdef VM86
120	if (tf->tf_eflags & PSL_VM) {
121		r[SVR4_X86_GS] = tf->tf_vm86_gs;
122		r[SVR4_X86_FS] = tf->tf_vm86_fs;
123		r[SVR4_X86_ES] = tf->tf_vm86_es;
124		r[SVR4_X86_DS] = tf->tf_vm86_ds;
125		r[SVR4_X86_EFL] = get_vflags(p);
126	} else
127#endif
128	{
129#if defined(__NetBSD__)
130	        __asm("movl %%gs,%w0" : "=r" (r[SVR4_X86_GS]));
131		__asm("movl %%fs,%w0" : "=r" (r[SVR4_X86_FS]));
132#else
133	        r[SVR4_X86_GS] = rgs();
134		r[SVR4_X86_FS] = tf->tf_fs;
135#endif
136		r[SVR4_X86_ES] = tf->tf_es;
137		r[SVR4_X86_DS] = tf->tf_ds;
138		r[SVR4_X86_EFL] = tf->tf_eflags;
139	}
140	r[SVR4_X86_EDI] = tf->tf_edi;
141	r[SVR4_X86_ESI] = tf->tf_esi;
142	r[SVR4_X86_EBP] = tf->tf_ebp;
143	r[SVR4_X86_ESP] = tf->tf_esp;
144	r[SVR4_X86_EBX] = tf->tf_ebx;
145	r[SVR4_X86_EDX] = tf->tf_edx;
146	r[SVR4_X86_ECX] = tf->tf_ecx;
147	r[SVR4_X86_EAX] = tf->tf_eax;
148	r[SVR4_X86_TRAPNO] = tf->tf_trapno;
149	r[SVR4_X86_ERR] = tf->tf_err;
150	r[SVR4_X86_EIP] = tf->tf_eip;
151	r[SVR4_X86_CS] = tf->tf_cs;
152	r[SVR4_X86_UESP] = 0;
153	r[SVR4_X86_SS] = tf->tf_ss;
154
155	/*
156	 * Set the signal stack
157	 */
158#if defined(DONE_MORE_SIGALTSTACK_WORK)
159	bsd_to_svr4_sigaltstack(sf, s);
160#else
161	s->ss_sp = (void *)(((u_long) tf->tf_esp) & ~(16384 - 1));
162	s->ss_size = 16384;
163	s->ss_flags = 0;
164#endif
165	PROC_UNLOCK(p);
166
167	/*
168	 * Set the signal mask
169	 */
170	bsd_to_svr4_sigset(mask, &uc->uc_sigmask);
171
172	/*
173	 * Set the flags
174	 */
175	uc->uc_flags = SVR4_UC_SIGMASK|SVR4_UC_CPU|SVR4_UC_STACK;
176}
177
178
179/*
180 * Set to ucontext specified. Reset signal mask and
181 * stack state from context.
182 * Return to previous pc and psl as specified by
183 * context left by sendsig. Check carefully to
184 * make sure that the user has not modified the
185 * psl to gain improper privileges or to cause
186 * a machine fault.
187 */
188int
189svr4_setcontext(p, uc)
190	struct proc *p;
191	struct svr4_ucontext *uc;
192{
193#if defined(DONE_MORE_SIGALTSTACK_WORK)
194	struct sigacts *psp;
195#endif
196	register struct trapframe *tf;
197	svr4_greg_t *r = uc->uc_mcontext.greg;
198	struct svr4_sigaltstack *s = &uc->uc_stack;
199	struct sigaltstack *sf;
200	sigset_t mask;
201
202	PROC_LOCK(p);
203#if defined(DONE_MORE_SIGALTSTACK_WORK)
204	psp = p->p_sigacts;
205#endif
206	sf = &p->p_sigstk;
207
208	/*
209	 * XXX:
210	 * Should we check the value of flags to determine what to restore?
211	 * What to do with uc_link?
212	 * What to do with floating point stuff?
213	 * Should we bother with the rest of the registers that we
214	 * set to 0 right now?
215	 */
216
217	if ((uc->uc_flags & SVR4_UC_CPU) == 0)
218		return 0;
219
220	DPRINTF(("svr4_setcontext(%d)\n", p->p_pid));
221
222	tf = p->p_md.md_regs;
223
224	/*
225	 * Restore register context.
226	 */
227#ifdef VM86
228#warning "VM86 doesn't work yet, please don't try to use it."
229	if (r[SVR4_X86_EFL] & PSL_VM) {
230		tf->tf_vm86_gs = r[SVR4_X86_GS];
231		tf->tf_vm86_fs = r[SVR4_X86_FS];
232		tf->tf_vm86_es = r[SVR4_X86_ES];
233		tf->tf_vm86_ds = r[SVR4_X86_DS];
234		set_vflags(p, r[SVR4_X86_EFL]);
235	} else
236#endif
237	{
238		/*
239		 * Check for security violations.  If we're returning to
240		 * protected mode, the CPU will validate the segment registers
241		 * automatically and generate a trap on violations.  We handle
242		 * the trap, rather than doing all of the checking here.
243		 */
244		if (((r[SVR4_X86_EFL] ^ tf->tf_eflags) & PSL_USERSTATIC) != 0 ||
245		    !USERMODE(r[SVR4_X86_CS], r[SVR4_X86_EFL]))
246			return (EINVAL);
247
248#if defined(__NetBSD__)
249		/* %fs and %gs were restored by the trampoline. */
250#else
251		/* %gs was restored by the trampoline. */
252		tf->tf_fs = r[SVR4_X86_FS];
253#endif
254		tf->tf_es = r[SVR4_X86_ES];
255		tf->tf_ds = r[SVR4_X86_DS];
256		tf->tf_eflags = r[SVR4_X86_EFL];
257	}
258	tf->tf_edi = r[SVR4_X86_EDI];
259	tf->tf_esi = r[SVR4_X86_ESI];
260	tf->tf_ebp = r[SVR4_X86_EBP];
261	tf->tf_ebx = r[SVR4_X86_EBX];
262	tf->tf_edx = r[SVR4_X86_EDX];
263	tf->tf_ecx = r[SVR4_X86_ECX];
264	tf->tf_eax = r[SVR4_X86_EAX];
265	tf->tf_trapno = r[SVR4_X86_TRAPNO];
266	tf->tf_err = r[SVR4_X86_ERR];
267	tf->tf_eip = r[SVR4_X86_EIP];
268	tf->tf_cs = r[SVR4_X86_CS];
269	tf->tf_ss = r[SVR4_X86_SS];
270	tf->tf_esp = r[SVR4_X86_ESP];
271
272	p->p_emuldata = uc->uc_link;
273	/*
274	 * restore signal stack
275	 */
276	if (uc->uc_flags & SVR4_UC_STACK) {
277		svr4_to_bsd_sigaltstack(s, sf);
278	}
279
280	/*
281	 * restore signal mask
282	 */
283	if (uc->uc_flags & SVR4_UC_SIGMASK) {
284#if defined(DEBUG_SVR4)
285		{
286			int i;
287			for (i = 0; i < 4; i++)
288				DPRINTF(("\tuc_sigmask[%d] = %lx\n", i,
289						uc->uc_sigmask.bits[i]));
290		}
291#endif
292		svr4_to_bsd_sigset(&uc->uc_sigmask, &mask);
293		SIG_CANTMASK(mask);
294		p->p_sigmask = mask;
295	}
296	PROC_UNLOCK(p);
297
298	return 0; /*EJUSTRETURN;*/
299}
300
301
302static void
303svr4_getsiginfo(si, sig, code, addr)
304	union svr4_siginfo	*si;
305	int			 sig;
306	u_long			 code;
307	caddr_t			 addr;
308{
309	si->si_signo = bsd_to_svr4_sig[sig];
310	si->si_errno = 0;
311	si->si_addr  = addr;
312
313	switch (code) {
314	case T_PRIVINFLT:
315		si->si_code = SVR4_ILL_PRVOPC;
316		si->si_trap = SVR4_T_PRIVINFLT;
317		break;
318
319	case T_BPTFLT:
320		si->si_code = SVR4_TRAP_BRKPT;
321		si->si_trap = SVR4_T_BPTFLT;
322		break;
323
324	case T_ARITHTRAP:
325		si->si_code = SVR4_FPE_INTOVF;
326		si->si_trap = SVR4_T_DIVIDE;
327		break;
328
329	case T_PROTFLT:
330		si->si_code = SVR4_SEGV_ACCERR;
331		si->si_trap = SVR4_T_PROTFLT;
332		break;
333
334	case T_TRCTRAP:
335		si->si_code = SVR4_TRAP_TRACE;
336		si->si_trap = SVR4_T_TRCTRAP;
337		break;
338
339	case T_PAGEFLT:
340		si->si_code = SVR4_SEGV_ACCERR;
341		si->si_trap = SVR4_T_PAGEFLT;
342		break;
343
344	case T_ALIGNFLT:
345		si->si_code = SVR4_BUS_ADRALN;
346		si->si_trap = SVR4_T_ALIGNFLT;
347		break;
348
349	case T_DIVIDE:
350		si->si_code = SVR4_FPE_FLTDIV;
351		si->si_trap = SVR4_T_DIVIDE;
352		break;
353
354	case T_OFLOW:
355		si->si_code = SVR4_FPE_FLTOVF;
356		si->si_trap = SVR4_T_DIVIDE;
357		break;
358
359	case T_BOUND:
360		si->si_code = SVR4_FPE_FLTSUB;
361		si->si_trap = SVR4_T_BOUND;
362		break;
363
364	case T_DNA:
365		si->si_code = SVR4_FPE_FLTINV;
366		si->si_trap = SVR4_T_DNA;
367		break;
368
369	case T_FPOPFLT:
370		si->si_code = SVR4_FPE_FLTINV;
371		si->si_trap = SVR4_T_FPOPFLT;
372		break;
373
374	case T_SEGNPFLT:
375		si->si_code = SVR4_SEGV_MAPERR;
376		si->si_trap = SVR4_T_SEGNPFLT;
377		break;
378
379	case T_STKFLT:
380		si->si_code = SVR4_ILL_BADSTK;
381		si->si_trap = SVR4_T_STKFLT;
382		break;
383
384	default:
385		si->si_code = 0;
386		si->si_trap = 0;
387#if defined(DEBUG_SVR4)
388		printf("sig %d code %ld\n", sig, code);
389/*		panic("svr4_getsiginfo");*/
390#endif
391		break;
392	}
393}
394
395
396/*
397 * Send an interrupt to process.
398 *
399 * Stack is set up to allow sigcode stored
400 * in u. to call routine. After the handler is
401 * done svr4 will call setcontext for us
402 * with the user context we just set up, and we
403 * will return to the user pc, psl.
404 */
405void
406svr4_sendsig(catcher, sig, mask, code)
407	sig_t catcher;
408	int sig;
409	sigset_t *mask;
410	u_long code;
411{
412	register struct proc *p = curproc;
413	register struct trapframe *tf;
414	struct svr4_sigframe *fp, frame;
415	struct sigacts *psp;
416	int oonstack;
417
418#if defined(DEBUG_SVR4)
419	printf("svr4_sendsig(%d)\n", sig);
420#endif
421	PROC_LOCK(p);
422	psp = p->p_sigacts;
423
424	tf = p->p_md.md_regs;
425	oonstack = sigonstack(tf->tf_esp);
426
427	/*
428	 * Allocate space for the signal handler context.
429	 */
430	if ((p->p_flag & P_ALTSTACK) && !oonstack &&
431	    SIGISMEMBER(psp->ps_sigonstack, sig)) {
432		fp = (struct svr4_sigframe *)(p->p_sigstk.ss_sp +
433		    p->p_sigstk.ss_size - sizeof(struct svr4_sigframe));
434		p->p_sigstk.ss_flags |= SS_ONSTACK;
435	} else {
436		fp = (struct svr4_sigframe *)tf->tf_esp - 1;
437	}
438	PROC_UNLOCK(p);
439
440	/*
441	 * Build the argument list for the signal handler.
442	 * Notes:
443	 * 	- we always build the whole argument list, even when we
444	 *	  don't need to [when SA_SIGINFO is not set, we don't need
445	 *	  to pass all sf_si and sf_uc]
446	 *	- we don't pass the correct signal address [we need to
447	 *	  modify many kernel files to enable that]
448	 */
449
450	svr4_getcontext(p, &frame.sf_uc, mask, oonstack);
451#if defined(DEBUG_SVR4)
452	printf("obtained ucontext\n");
453#endif
454	svr4_getsiginfo(&frame.sf_si, sig, code, (caddr_t) tf->tf_eip);
455#if defined(DEBUG_SVR4)
456	printf("obtained siginfo\n");
457#endif
458	frame.sf_signum = frame.sf_si.si_signo;
459	frame.sf_sip = &fp->sf_si;
460	frame.sf_ucp = &fp->sf_uc;
461	frame.sf_handler = catcher;
462#if defined(DEBUG_SVR4)
463	printf("sig = %d, sip %p, ucp = %p, handler = %p\n",
464	       frame.sf_signum, frame.sf_sip, frame.sf_ucp, frame.sf_handler);
465#endif
466
467	if (copyout(&frame, fp, sizeof(frame)) != 0) {
468		/*
469		 * Process has trashed its stack; give it an illegal
470		 * instruction to halt it in its tracks.
471		 */
472		PROC_LOCK(p);
473		sigexit(p, SIGILL);
474		/* NOTREACHED */
475	}
476#if defined(__NetBSD__)
477	/*
478	 * Build context to run handler in.
479	 */
480	tf->tf_es = GSEL(GUSERLDT_SEL, SEL_UPL);
481	tf->tf_ds = GSEL(GUSERLDT_SEL, SEL_UPL);
482	tf->tf_eip = (int)(((char *)PS_STRINGS) -
483	     svr4_szsigcode);
484	tf->tf_cs = GSEL(GUSERLDT_SEL, SEL_UPL);
485
486	tf->tf_eflags &= ~(PSL_T|PSL_VM|PSL_AC);
487	tf->tf_esp = (int)fp;
488	tf->tf_ss = GSEL(GUSERLDT_SEL, SEL_UPL);
489#else
490	tf->tf_esp = (int)fp;
491	tf->tf_eip = (int)(((char *)PS_STRINGS) - *(p->p_sysent->sv_szsigcode));
492	tf->tf_cs = _ucodesel;
493	tf->tf_ds = _udatasel;
494	tf->tf_es = _udatasel;
495	tf->tf_fs = _udatasel;
496	load_gs(_udatasel);
497	tf->tf_ss = _udatasel;
498#endif
499}
500
501
502
503int
504svr4_sys_sysarch(p, v)
505	struct proc *p;
506	struct svr4_sys_sysarch_args *v;
507{
508	struct svr4_sys_sysarch_args *uap = v;
509#if 0	/* USER_LDT */
510#if defined(__NetBSD__)
511	caddr_t sg = stackgap_init(p->p_emul);
512#else
513	caddr_t sg = stackgap_init();
514#endif
515	int error;
516#endif
517
518	switch (uap->op) {
519	case SVR4_SYSARCH_FPHW:
520		return 0;
521
522	case SVR4_SYSARCH_DSCR:
523#if 0	/* USER_LDT */
524#warning "USER_LDT doesn't work - are you sure you want this?"
525		{
526			struct i386_set_ldt_args sa, *sap;
527			struct sys_sysarch_args ua;
528
529			struct svr4_ssd ssd;
530			union descriptor bsd;
531
532			if ((error = copyin(SCARG(uap, a1), &ssd,
533					    sizeof(ssd))) != 0) {
534				printf("Cannot copy arg1\n");
535				return error;
536			}
537
538			printf("s=%x, b=%x, l=%x, a1=%x a2=%x\n",
539			       ssd.selector, ssd.base, ssd.limit,
540			       ssd.access1, ssd.access2);
541
542			/* We can only set ldt's for now. */
543			if (!ISLDT(ssd.selector)) {
544				printf("Not an ldt\n");
545				return EPERM;
546			}
547
548			/* Oh, well we don't cleanup either */
549			if (ssd.access1 == 0)
550				return 0;
551
552			bsd.sd.sd_lobase = ssd.base & 0xffffff;
553			bsd.sd.sd_hibase = (ssd.base >> 24) & 0xff;
554
555			bsd.sd.sd_lolimit = ssd.limit & 0xffff;
556			bsd.sd.sd_hilimit = (ssd.limit >> 16) & 0xf;
557
558			bsd.sd.sd_type = ssd.access1 & 0x1f;
559			bsd.sd.sd_dpl =  (ssd.access1 >> 5) & 0x3;
560			bsd.sd.sd_p = (ssd.access1 >> 7) & 0x1;
561
562			bsd.sd.sd_xx = ssd.access2 & 0x3;
563			bsd.sd.sd_def32 = (ssd.access2 >> 2) & 0x1;
564			bsd.sd.sd_gran = (ssd.access2 >> 3)& 0x1;
565
566			sa.start = IDXSEL(ssd.selector);
567			sa.desc = stackgap_alloc(&sg, sizeof(union descriptor));
568			sa.num = 1;
569			sap = stackgap_alloc(&sg,
570					     sizeof(struct i386_set_ldt_args));
571
572			if ((error = copyout(&sa, sap, sizeof(sa))) != 0) {
573				printf("Cannot copyout args\n");
574				return error;
575			}
576
577			SCARG(&ua, op) = I386_SET_LDT;
578			SCARG(&ua, parms) = (char *) sap;
579
580			if ((error = copyout(&bsd, sa.desc, sizeof(bsd))) != 0) {
581				printf("Cannot copyout desc\n");
582				return error;
583			}
584
585			return sys_sysarch(p, &ua, retval);
586		}
587#endif
588
589	default:
590		printf("svr4_sysarch(%d), a1 %p\n", uap->op,
591		       uap->a1);
592		return 0;
593	}
594}
595