1 /*	$NetBSD: linux_machdep.c,v 1.13 2002/04/08 13:27:37 christos Exp $	*/
2 
3 /*-
4  * Copyright (c) 1998 The NetBSD Foundation, Inc.
5  * All rights reserved.
6  *
7  * This code is derived from software contributed to The NetBSD Foundation
8  * by ITOH Yasufumi.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  * 3. All advertising materials mentioning features or use of this software
19  *    must display the following acknowledgement:
20  *	This product includes software developed by the NetBSD
21  *	Foundation, Inc. and its contributors.
22  * 4. Neither the name of The NetBSD Foundation nor the names of its
23  *    contributors may be used to endorse or promote products derived
24  *    from this software without specific prior written permission.
25  *
26  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
27  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
28  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
29  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
30  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
31  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
32  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
33  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
34  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
35  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
36  * POSSIBILITY OF SUCH DAMAGE.
37  */
38 
39 #include <sys/cdefs.h>
40 __KERNEL_RCSID(0, "$NetBSD: linux_machdep.c,v 1.13 2002/04/08 13:27:37 christos Exp $");
41 
42 #define COMPAT_LINUX 1
43 
44 #include <sys/param.h>
45 #include <sys/systm.h>
46 #include <sys/kernel.h>
47 #include <sys/proc.h>
48 #include <sys/exec.h>
49 #include <sys/ioctl.h>
50 #include <sys/mount.h>
51 #include <sys/signal.h>
52 #include <sys/signalvar.h>
53 #include <sys/syscallargs.h>
54 
55 #include <machine/cpu.h>
56 #include <machine/reg.h>
57 
58 #include <compat/linux/common/linux_types.h>
59 #include <compat/linux/common/linux_signal.h>
60 #include <compat/linux/common/linux_ioctl.h>
61 #include <compat/linux/common/linux_exec.h>
62 #include <compat/linux/common/linux_machdep.h>
63 
64 #include <compat/linux/linux_syscall.h>
65 #include <compat/linux/linux_syscallargs.h>
66 
67 /* XXX should be in an include file somewhere */
68 #define CC_PURGE	1
69 #define CC_FLUSH	2
70 #define CC_IPURGE	4
71 #define CC_EXTPURGE	0x80000000
72 /* XXX end should be */
73 
74 extern short exframesize[];
75 
76 #ifdef DEBUG
77 extern int sigdebug;
78 extern int sigpid;
79 #define SDB_FOLLOW	0x01
80 #define SDB_KSTACK	0x02
81 #define SDB_FPSTATE	0x04
82 #endif
83 
84 void setup_linux_sigframe __P((struct frame *frame, int sig, sigset_t *mask,
85 				caddr_t usp));
86 void setup_linux_rt_sigframe __P((struct frame *frame, int sig, sigset_t *mask,
87 				caddr_t usp, struct proc *p));
88 
89 /*
90  * Deal with some m68k-specific things in the Linux emulation code.
91  */
92 
93 /*
94  * Setup registers on program execution.
95  */
96 void
97 linux_setregs(p, epp, stack)
98 	struct proc *p;
99 	struct exec_package *epp;
100 	u_long stack;
101 {
102 
103 	setregs(p, epp, stack);
104 }
105 
106 /*
107  * Setup signal frame for old signal interface.
108  */
109 void
110 setup_linux_sigframe(frame, sig, mask, usp)
111 	struct frame *frame;
112 	int sig;
113 	sigset_t *mask;
114 	caddr_t usp;
115 {
116 	struct proc *p = curproc;
117 	struct linux_sigframe *fp, kf;
118 	short ft;
119 
120 	ft = frame->f_format;
121 
122 	/* Allocate space for the signal handler context on the user stack. */
123 	fp = (struct linux_sigframe *) usp;
124 	fp--;
125 
126 #ifdef DEBUG
127 	if ((sigdebug & SDB_KSTACK) && p->p_pid == sigpid)
128 		printf("setup_linux_sigframe(%d): sig %d ssp %p usp %p scp %p ft %d\n",
129 		       p->p_pid, sig, &ft, fp, &fp->sf_c.c_sc, ft);
130 #endif
131 
132 	/* Build stack frame. */
133 	kf.sf_psigtramp = fp->sf_sigtramp;	/* return addr for handler */
134 	kf.sf_signum = native_to_linux_signo[sig];
135 	kf.sf_code = frame->f_vector;		/* Does anyone use it? */
136 	kf.sf_scp = &fp->sf_c.c_sc;
137 
138 	/* The sigtramp code is on the stack frame on Linux/m68k. */
139 	kf.sf_sigtramp[0] = LINUX_SF_SIGTRAMP0;
140 	kf.sf_sigtramp[1] = LINUX_SF_SIGTRAMP1;
141 
142 	/*
143 	 * Save necessary hardware state.  Currently this includes:
144 	 *	- scratch registers
145 	 *	- original exception frame (if not a "normal" frame)
146 	 *	- FP coprocessor state
147 	 */
148 	kf.sf_c.c_sc.sc_d0 = frame->f_regs[D0];
149 	kf.sf_c.c_sc.sc_d1 = frame->f_regs[D1];
150 	kf.sf_c.c_sc.sc_a0 = frame->f_regs[A0];
151 	kf.sf_c.c_sc.sc_a1 = frame->f_regs[A1];
152 
153 	/* Clear for security (and initialize ss_format). */
154 	bzero(&kf.sf_c.c_sc.sc_ss, sizeof kf.sf_c.c_sc.sc_ss);
155 
156 	if (ft >= FMT4) {
157 #ifdef DEBUG
158 		if (ft > 15 || exframesize[ft] < 0)
159 			panic("setup_linux_sigframe: bogus frame type");
160 #endif
161 		kf.sf_c.c_sc.sc_ss.ss_format = ft;
162 		kf.sf_c.c_sc.sc_ss.ss_vector = frame->f_vector;
163 		bcopy(&frame->F_u, &kf.sf_c.c_sc.sc_ss.ss_frame,
164 			(size_t) exframesize[ft]);
165 		/*
166 		 * Leave an indicator that we need to clean up the kernel
167 		 * stack.  We do this by setting the "pad word" above the
168 		 * hardware stack frame to the amount the stack must be
169 		 * adjusted by.
170 		 *
171 		 * N.B. we increment rather than just set f_stackadj in
172 		 * case we are called from syscall when processing a
173 		 * sigreturn.  In that case, f_stackadj may be non-zero.
174 		 */
175 		frame->f_stackadj += exframesize[ft];
176 		frame->f_format = frame->f_vector = 0;
177 #ifdef DEBUG
178 		if (sigdebug & SDB_FOLLOW)
179 			printf("setup_linux_sigframe(%d): copy out %d of frame %d\n",
180 			       p->p_pid, exframesize[ft], ft);
181 #endif
182 	}
183 
184 	switch (fputype) {
185 	case FPU_NONE:
186 		break;
187 #ifdef M68060
188 	case FPU_68060:
189 		asm("fsave %0" : "=m" (kf.sf_c.c_sc.sc_ss.ss_fpstate.FPF_u1)
190 			: : "memory");
191 		if (((struct fpframe060 *)&kf.sf_c.c_sc.sc_ss.ss_fpstate.FPF_u1)
192 					->fpf6_frmfmt != FPF6_FMT_NULL) {
193 			asm("fmovem %%fp0-%%fp1,%0" :
194 				"=m" (*kf.sf_c.c_sc.sc_ss.ss_fpstate.fpf_regs));
195 			/*
196 			 * On 060,  "fmovem fpcr/fpsr/fpi,<ea>"  is
197 			 * emulated by software and slow.
198 			 */
199 			asm("fmovem %%fpcr,%0; fmovem %%fpsr,%1; fmovem %%fpi,%2" :
200 				"=m" (kf.sf_c.c_sc.sc_ss.ss_fpstate.fpf_fpcr),
201 				"=m" (kf.sf_c.c_sc.sc_ss.ss_fpstate.fpf_fpsr),
202 				"=m" (kf.sf_c.c_sc.sc_ss.ss_fpstate.fpf_fpiar));
203 		}
204 		break;
205 #endif
206 	default:
207 		asm("fsave %0" : "=m" (kf.sf_c.c_sc.sc_ss.ss_fpstate.FPF_u1)
208 			: : "memory");
209 		if (kf.sf_c.c_sc.sc_ss.ss_fpstate.fpf_version) {
210 			asm("fmovem %%fp0-%%fp1,%0; fmovem %%fpcr/%%fpsr/%%fpi,%1" :
211 				"=m" (*kf.sf_c.c_sc.sc_ss.ss_fpstate.fpf_regs),
212 				"=m" (kf.sf_c.c_sc.sc_ss.ss_fpstate.fpf_fpcr)
213 				: : "memory");
214 		}
215 		break;
216 	}
217 #ifdef DEBUG
218 	if ((sigdebug & SDB_FPSTATE) && *(char *)&kf.sf_c.c_sc.sc_ss.ss_fpstate)
219 		printf("setup_linux_sigframe(%d): copy out FP state (%x) to %p\n",
220 		       p->p_pid, *(u_int *)&kf.sf_c.c_sc.sc_ss.ss_fpstate,
221 		       &kf.sf_c.c_sc.sc_ss.ss_fpstate);
222 #endif
223 
224 	/* Build the signal context to be used by sigreturn. */
225 #if LINUX__NSIG_WORDS > 1
226 	native_to_linux_old_extra_sigset(&kf.sf_c.c_sc.sc_mask,
227 	    kf.sf_c.c_extrasigmask, mask);
228 #else
229 	native_to_linux_old_sigset(&kf.sf_c.c_sc.sc_mask, mask);
230 #endif
231 	kf.sf_c.c_sc.sc_sp = frame->f_regs[SP];
232 	kf.sf_c.c_sc.sc_pc = frame->f_pc;
233 	kf.sf_c.c_sc.sc_ps = frame->f_sr;
234 
235 	if (copyout(&kf, fp, sizeof(struct linux_sigframe))) {
236 #ifdef DEBUG
237 		if ((sigdebug & SDB_KSTACK) && p->p_pid == sigpid)
238 			printf("setup_linux_sigframe(%d): copyout failed on sig %d\n",
239 			       p->p_pid, sig);
240 #endif
241 		/*
242 		 * Process has trashed its stack; give it a segmentation
243 		 * violation to halt it in its tracks.
244 		 */
245 		sigexit(p, SIGSEGV);
246 		/* NOTREACHED */
247 	}
248 
249 	/*
250 	 * The signal trampoline is on the signal frame.
251 	 * Clear the instruction cache in case of cached.
252 	 */
253 	cachectl1(CC_EXTPURGE | CC_IPURGE,
254 			(vaddr_t) fp->sf_sigtramp, sizeof fp->sf_sigtramp, p);
255 
256 	/* Set up the user stack pointer. */
257 	frame->f_regs[SP] = (int)fp;
258 
259 #ifdef DEBUG
260 	if (sigdebug & SDB_FOLLOW)
261 		printf("setup_linux_sigframe(%d): sig %d scp %p fp %p sc_sp %x\n",
262 		       p->p_pid, sig, kf.sf_scp, fp, kf.sf_c.c_sc.sc_sp);
263 #endif
264 }
265 
266 /*
267  * Setup signal frame for new RT signal interface.
268  */
269 void
270 setup_linux_rt_sigframe(frame, sig, mask, usp, p)
271 	struct frame *frame;
272 	int sig;
273 	sigset_t *mask;
274 	caddr_t usp;
275 	struct proc *p;
276 {
277 	struct linux_rt_sigframe *fp, kf;
278 	short ft;
279 
280 	ft = frame->f_format;
281 
282 	/* Allocate space for the signal handler context on the user stack. */
283 	fp = (struct linux_rt_sigframe *) usp;
284 	fp--;
285 
286 #ifdef DEBUG
287 	if ((sigdebug & SDB_KSTACK) && p->p_pid == sigpid)
288 		printf("setup_linux_rt_sigframe(%d): sig %d ssp %p usp %p ucp %p ft %d\n",
289 		       p->p_pid, sig, &ft, fp, &fp->sf_uc, ft);
290 #endif
291 
292 	/* Build stack frame. */
293 	kf.sf_psigtramp = fp->sf_sigtramp;	/* return addr for handler */
294 	kf.sf_signum = native_to_linux_signo[sig];
295 	kf.sf_pinfo = &fp->sf_info;
296 	kf.sf_puc = &fp->sf_uc;
297 
298 	/* The sigtramp code is on the stack frame on Linux/m68k. */
299 	kf.sf_sigtramp[0] = LINUX_RT_SF_SIGTRAMP0;
300 	kf.sf_sigtramp[1] = LINUX_RT_SF_SIGTRAMP1;
301 
302 	/* clear for security (and initialize uc_flags, ss_format, etc.). */
303 	bzero(&kf.sf_uc, sizeof(struct linux_ucontext));
304 
305 	/*
306 	 * Save necessary hardware state.  Currently this includes:
307 	 *	- general registers
308 	 *	- original exception frame (if not a "normal" frame)
309 	 *	- FP coprocessor state
310 	 */
311 	/* version of mcontext */
312 	kf.sf_uc.uc_mc.mc_version = LINUX_MCONTEXT_VERSION;
313 
314 	/* general registers and pc/sr */
315 	bcopy(frame->f_regs, kf.sf_uc.uc_mc.mc_gregs.gr_regs, sizeof(u_int)*16);
316 	kf.sf_uc.uc_mc.mc_gregs.gr_pc = frame->f_pc;
317 	kf.sf_uc.uc_mc.mc_gregs.gr_sr = frame->f_sr;
318 
319 	if (ft >= FMT4) {
320 #ifdef DEBUG
321 		if (ft > 15 || exframesize[ft] < 0)
322 			panic("setup_linux_rt_sigframe: bogus frame type");
323 #endif
324 		kf.sf_uc.uc_ss.ss_format = ft;
325 		kf.sf_uc.uc_ss.ss_vector = frame->f_vector;
326 		bcopy(&frame->F_u, &kf.sf_uc.uc_ss.ss_frame,
327 			(size_t) exframesize[ft]);
328 		/*
329 		 * Leave an indicator that we need to clean up the kernel
330 		 * stack.  We do this by setting the "pad word" above the
331 		 * hardware stack frame to the amount the stack must be
332 		 * adjusted by.
333 		 *
334 		 * N.B. we increment rather than just set f_stackadj in
335 		 * case we are called from syscall when processing a
336 		 * sigreturn.  In that case, f_stackadj may be non-zero.
337 		 */
338 		frame->f_stackadj += exframesize[ft];
339 		frame->f_format = frame->f_vector = 0;
340 #ifdef DEBUG
341 		if (sigdebug & SDB_FOLLOW)
342 			printf("setup_linux_rt_sigframe(%d): copy out %d of frame %d\n",
343 			       p->p_pid, exframesize[ft], ft);
344 #endif
345 	}
346 
347 	switch (fputype) {
348 	case FPU_NONE:
349 		break;
350 #ifdef M68060
351 	case FPU_68060:
352 		asm("fsave %0" : "=m" (kf.sf_uc.uc_ss.ss_fpstate));
353 				/* See note below. */
354 		if (((struct fpframe060 *) &kf.sf_uc.uc_ss.ss_fpstate.FPF_u1)
355 					->fpf6_frmfmt != FPF6_FMT_NULL) {
356 			asm("fmovem %%fp0-%%fp7,%0" :
357 				"=m" (*kf.sf_uc.uc_mc.mc_fpregs.fpr_regs));
358 			/*
359 			 * On 060,  "fmovem fpcr/fpsr/fpi,<ea>"  is
360 			 * emulated by software and slow.
361 			 */
362 			asm("fmovem %%fpcr,%0; fmovem %%fpsr,%1; fmovem %%fpi,%2" :
363 				"=m" (kf.sf_uc.uc_mc.mc_fpregs.fpr_fpcr),
364 				"=m" (kf.sf_uc.uc_mc.mc_fpregs.fpr_fpsr),
365 				"=m" (kf.sf_uc.uc_mc.mc_fpregs.fpr_fpiar));
366 		}
367 		break;
368 #endif
369 	default:
370 		/*
371 		 * NOTE:  We give whole of the  "struct linux_rt_fpframe"
372 		 * to the asm("fsave") argument; not the FPF_u1 element only.
373 		 * Unlike the non-RT version of this structure,
374 		 * this contains only the FPU state used by "fsave"
375 		 * (and whole of the information is in the structure).
376 		 * This gives the correct dependency information to the asm(),
377 		 * and no "memory" is required to the ``clobberd'' list.
378 		 */
379 		asm("fsave %0" : "=m" (kf.sf_uc.uc_ss.ss_fpstate));
380 		if (kf.sf_uc.uc_ss.ss_fpstate.fpf_version) {
381 			asm("fmovem %%fp0-%%fp7,%0; fmovem %%fpcr/%%fpsr/%%fpi,%1" :
382 				"=m" (*kf.sf_uc.uc_mc.mc_fpregs.fpr_regs),
383 				"=m" (kf.sf_uc.uc_mc.mc_fpregs.fpr_fpcr)
384 				: : "memory");
385 		}
386 		break;
387 	}
388 #ifdef DEBUG
389 	if ((sigdebug & SDB_FPSTATE) && *(char *)&kf.sf_uc.uc_ss.ss_fpstate)
390 		printf("setup_linux_rt_sigframe(%d): copy out FP state (%x) to %p\n",
391 		       p->p_pid, *(u_int *)&kf.sf_uc.uc_ss.ss_fpstate,
392 		       &kf.sf_uc.uc_ss.ss_fpstate);
393 #endif
394 
395 	/*
396 	 * XXX XAX Create bogus siginfo data.  This can't really
397 	 * XXX be fixed until NetBSD has realtime signals.
398 	 * XXX Or we do the emuldata thing.
399 	 * XXX -erh
400 	 */
401 	bzero(&kf.sf_info, sizeof(struct linux_siginfo));
402 	kf.sf_info.lsi_signo = sig;
403 	kf.sf_info.lsi_code = LINUX_SI_USER;
404 	kf.sf_info.lsi_pid = p->p_pid;
405 	kf.sf_info.lsi_uid = p->p_ucred->cr_uid;	/* Use real uid here? */
406 
407 	/* Build the signal context to be used by sigreturn. */
408 	native_to_linux_sigset(&kf.sf_uc.uc_sigmask, mask);
409 	kf.sf_uc.uc_stack.ss_sp = p->p_sigctx.ps_sigstk.ss_sp;
410 	kf.sf_uc.uc_stack.ss_flags =
411 		(p->p_sigctx.ps_sigstk.ss_flags & SS_ONSTACK ? LINUX_SS_ONSTACK : 0) |
412 		(p->p_sigctx.ps_sigstk.ss_flags & SS_DISABLE ? LINUX_SS_DISABLE : 0);
413 	kf.sf_uc.uc_stack.ss_size = p->p_sigctx.ps_sigstk.ss_size;
414 
415 	if (copyout(&kf, fp, sizeof(struct linux_rt_sigframe))) {
416 #ifdef DEBUG
417 		if ((sigdebug & SDB_KSTACK) && p->p_pid == sigpid)
418 			printf("setup_linux_rt_sigframe(%d): copyout failed on sig %d\n",
419 			       p->p_pid, sig);
420 #endif
421 		/*
422 		 * Process has trashed its stack; give it a segmentation
423 		 * violation to halt it in its tracks.
424 		 */
425 		sigexit(p, SIGSEGV);
426 		/* NOTREACHED */
427 	}
428 
429 	/*
430 	 * The signal trampoline is on the signal frame.
431 	 * Clear the instruction cache in case of cached.
432 	 */
433 	cachectl1(CC_EXTPURGE | CC_IPURGE,
434 			(vaddr_t) fp->sf_sigtramp, sizeof fp->sf_sigtramp, p);
435 
436 	/* Set up the user stack pointer. */
437 	frame->f_regs[SP] = (int)fp;
438 
439 #ifdef DEBUG
440 	if (sigdebug & SDB_FOLLOW)
441 		printf("setup_linux_rt_sigframe(%d): sig %d puc %p fp %p sc_sp %x\n",
442 		       p->p_pid, sig, kf.sf_puc, fp,
443 		       kf.sf_uc.uc_mc.mc_gregs.gr_regs[SP]);
444 #endif
445 }
446 
447 /*
448  * Send an interrupt to Linux process.
449  */
450 void
451 linux_sendsig(catcher, sig, mask, code)
452 	sig_t catcher;
453 	int sig;
454 	sigset_t *mask;
455 	u_long code;
456 {
457 	struct proc *p = curproc;
458 	struct frame *frame;
459 	caddr_t usp;		/* user stack for signal context */
460 	int onstack;
461 
462 	frame = (struct frame *)p->p_md.md_regs;
463 
464 	/* Do we need to jump onto the signal stack? */
465 	onstack = (p->p_sigctx.ps_sigstk.ss_flags & (SS_DISABLE | SS_ONSTACK)) == 0 &&
466 		  (SIGACTION(p, sig).sa_flags & SA_ONSTACK) != 0;
467 
468 	/* Determine user stack for the signal handler context. */
469 	if (onstack)
470 		usp = (caddr_t)p->p_sigctx.ps_sigstk.ss_sp
471 				+ p->p_sigctx.ps_sigstk.ss_size;
472 	else
473 		usp = (caddr_t)frame->f_regs[SP];
474 
475 	/* Setup the signal frame (and part of the trapframe). */
476 	if (SIGACTION(p, sig).sa_flags & SA_SIGINFO)
477 		setup_linux_rt_sigframe(frame, sig, mask, usp, p);
478 	else
479 		setup_linux_sigframe(frame, sig, mask, usp);
480 
481 	/* Call the signal handler. */
482 	frame->f_pc = (u_int) catcher;
483 
484 	/* Remember that we're now on the signal stack. */
485 	if (onstack)
486 		p->p_sigctx.ps_sigstk.ss_flags |= SS_ONSTACK;
487 
488 #ifdef DEBUG
489 	if ((sigdebug & SDB_KSTACK) && p->p_pid == sigpid)
490 		printf("linux_sendsig(%d): sig %d returns\n",
491 		       p->p_pid, sig);
492 #endif
493 }
494 
495 /*
496  * The linux_sys_sigreturn and linux_sys_rt_sigreturn
497  * system calls cleanup state after a signal
498  * has been taken.  Reset signal mask and stack
499  * state from context left by linux_sendsig (above).
500  * Return to previous pc and psl as specified by
501  * context left by linux_sendsig. Check carefully to
502  * make sure that the user has not modified the
503  * psl to gain improper privileges or to cause
504  * a machine fault.
505  *
506  * Note that the sigreturn system calls of Linux/m68k
507  * do not return on errors, but issue segmentation
508  * violation and terminate the process.
509  */
510 /* ARGSUSED */
511 int
512 linux_sys_sigreturn(p, v, retval)
513 	struct proc *p;
514 	void *v;
515 	register_t *retval;
516 {
517 	struct frame *frame;
518 	struct linux_sigc2 tsigc2;	/* extra mask and sigcontext */
519 	struct linux_sigcontext *scp;	/* pointer to sigcontext */
520 	sigset_t mask;
521 	int sz = 0;			/* extra frame size */
522 	int usp;
523 
524 	/*
525 	 * sigreturn of Linux/m68k takes no arguments.
526 	 * The user stack points at struct linux_sigc2.
527 	 */
528 	frame = (struct frame *) p->p_md.md_regs;
529 	usp = frame->f_regs[SP];
530 	if (usp & 1)
531 		goto bad;
532 
533 #ifdef DEBUG
534 	if (sigdebug & SDB_FOLLOW)
535 		printf("linux_sys_sigreturn: pid %d, usp %p\n",
536 			p->p_pid, (caddr_t) usp);
537 #endif
538 
539 	/* Grab whole of the sigcontext. */
540 	if (copyin((caddr_t) usp, &tsigc2, sizeof tsigc2))
541 bad:		sigexit(p, SIGSEGV);
542 
543 	scp = &tsigc2.c_sc;
544 
545 	/*
546 	 * Check kernel stack and re-enter to syscall() if needed.
547 	 */
548 	if ((sz = scp->sc_ss.ss_format) != 0) {
549 		if ((sz = exframesize[sz]) < 0)
550 			goto bad;
551 		if (sz && frame->f_stackadj == 0) {
552 			/*
553 			 * Extra stack space is required but not allocated.
554 			 * Allocate and re-enter syscall().
555 			 */
556 			reenter_syscall(frame, sz);
557 			/* NOTREACHED */
558 		}
559 	}
560 #ifdef DEBUG
561 	/* reenter_syscall() doesn't adjust stack. */
562 	if (sz != frame->f_stackadj)
563 		panic("linux_sys_sigreturn: adj: %d != %d",
564 			sz, frame->f_stackadj);
565 #endif
566 
567 	/* Restore signal stack. */
568 	p->p_sigctx.ps_sigstk.ss_flags &= ~SS_ONSTACK;
569 
570 	/* Restore signal mask. */
571 #if LINUX__NSIG_WORDS > 1
572 	linux_old_extra_to_native_sigset(&mask, &scp->sc_mask,
573 					 tsigc2.c_extrasigmask);
574 #else
575 	linux_old_to_native_sigset(&scp->sc_mask, &mask);
576 #endif
577 	(void) sigprocmask1(p, SIG_SETMASK, &mask, 0);
578 
579 	/*
580 	 * Restore the user supplied information.
581 	 */
582 	frame->f_regs[SP] = scp->sc_sp;
583 	frame->f_regs[D0] = scp->sc_d0;
584 	frame->f_regs[D1] = scp->sc_d1;
585 	frame->f_regs[A0] = scp->sc_a0;
586 	frame->f_regs[A1] = scp->sc_a1;
587 	frame->f_pc = scp->sc_pc;
588 	/* Privileged bits of  sr  are silently ignored on Linux/m68k. */
589 	frame->f_sr = scp->sc_ps & ~(PSL_MBZ|PSL_IPL|PSL_S);
590 	/*
591 	 * Other registers are assumed to be unchanged,
592 	 * and not restored.
593 	 */
594 
595 	/*
596 	 * Restore long stack frames.  Note that we do not copy
597 	 * back the saved SR or PC, they were picked up above from
598 	 * the sigcontext structure.
599 	 */
600 	if (scp->sc_ss.ss_format) {
601 		frame->f_format = scp->sc_ss.ss_format;
602 		frame->f_vector = scp->sc_ss.ss_vector;
603 		if (frame->f_stackadj < sz)	/* just in case... */
604 			goto bad;
605 		frame->f_stackadj -= sz;
606 		bcopy(&scp->sc_ss.ss_frame, &frame->F_u, sz);
607 #ifdef DEBUG
608 		if (sigdebug & SDB_FOLLOW)
609 			printf("linux_sys_sigreturn(%d): copy in %d of frame type %d\n",
610 			       p->p_pid, sz, scp->sc_ss.ss_format);
611 #endif
612 	}
613 
614 	/*
615 	 * Finally we restore the original FP context.
616 	 */
617 	switch (fputype) {
618 	case FPU_NONE:
619 		break;
620 #ifdef M68060
621 	case FPU_68060:
622 		if (((struct fpframe060*)&scp->sc_ss.ss_fpstate.FPF_u1)
623 					->fpf6_frmfmt != FPF6_FMT_NULL) {
624 			/*
625 			 * On 060,  "fmovem <ea>,fpcr/fpsr/fpi"  is
626 			 * emulated by software and slow.
627 			 */
628 			asm("fmovem %0,%%fpcr; fmovem %1,%%fpsr; fmovem %2,%%fpi"::
629 				"m" (scp->sc_ss.ss_fpstate.fpf_fpcr),
630 				"m" (scp->sc_ss.ss_fpstate.fpf_fpsr),
631 				"m" (scp->sc_ss.ss_fpstate.fpf_fpiar));
632 			asm("fmovem %0,%%fp0-%%fp1" : :
633 				"m" (*scp->sc_ss.ss_fpstate.fpf_regs));
634 		}
635 		asm("frestore %0" : : "m" (scp->sc_ss.ss_fpstate.FPF_u1));
636 		break;
637 #endif
638 	default:
639 		if (scp->sc_ss.ss_fpstate.fpf_version) {
640 			asm("fmovem %0,%%fpcr/%%fpsr/%%fpi; fmovem %1,%%fp0-%%fp1"::
641 				"m" (scp->sc_ss.ss_fpstate.fpf_fpcr),
642 				"m" (*scp->sc_ss.ss_fpstate.fpf_regs));
643 		}
644 		asm("frestore %0" : : "m" (scp->sc_ss.ss_fpstate.FPF_u1));
645 		break;
646 	}
647 
648 #ifdef DEBUG
649 	if ((sigdebug & SDB_FPSTATE) && *(char *)&scp->sc_ss.ss_fpstate)
650 		printf("linux_sys_sigreturn(%d): copied in FP state (%x) at %p\n",
651 		       p->p_pid, *(u_int *)&scp->sc_ss.ss_fpstate,
652 		       &scp->sc_ss.ss_fpstate);
653 	if ((sigdebug & SDB_FOLLOW) ||
654 	    ((sigdebug & SDB_KSTACK) && p->p_pid == sigpid))
655 		printf("linux_sys_sigreturn(%d): returns\n", p->p_pid);
656 #endif
657 
658 	return EJUSTRETURN;
659 }
660 
661 /* ARGSUSED */
662 int
663 linux_sys_rt_sigreturn(p, v, retval)
664 	struct proc *p;
665 	void *v;
666 	register_t *retval;
667 {
668 	struct frame *frame;
669 	struct linux_ucontext *ucp;	/* ucontext in user space */
670 	struct linux_ucontext tuc;	/* copy of *ucp */
671 	sigset_t mask;
672 	int sz = 0;			/* extra frame size */
673 
674 	/*
675 	 * rt_sigreturn of Linux/m68k takes no arguments.
676 	 * usp + 4 is a pointer to siginfo structure,
677 	 * usp + 8 is a pointer to ucontext structure.
678 	 */
679 	frame = (struct frame *) p->p_md.md_regs;
680 	ucp = (struct linux_ucontext *) fuword((caddr_t)frame->f_regs[SP] + 8);
681 	if ((int) ucp & 1)
682 		goto bad;		/* error (-1) or odd address */
683 
684 #ifdef DEBUG
685 	if (sigdebug & SDB_FOLLOW)
686 		printf("linux_rt_sigreturn: pid %d, ucp %p\n", p->p_pid, ucp);
687 #endif
688 
689 	/* Grab whole of the ucontext. */
690 	if (copyin(ucp, &tuc, sizeof tuc))
691 bad:		sigexit(p, SIGSEGV);
692 
693 	/*
694 	 * Check kernel stack and re-enter to syscall() if needed.
695 	 */
696 	if ((sz = tuc.uc_ss.ss_format) != 0) {
697 		if ((sz = exframesize[sz]) < 0)
698 			goto bad;
699 		if (sz && frame->f_stackadj == 0) {
700 			/*
701 			 * Extra stack space is required but not allocated.
702 			 * Allocate and re-enter syscall().
703 			 */
704 			reenter_syscall(frame, sz);
705 			/* NOTREACHED */
706 		}
707 	}
708 #ifdef DEBUG
709 	/* reenter_syscall() doesn't adjust stack. */
710 	if (sz != frame->f_stackadj)
711 		panic("linux_sys_rt_sigreturn: adj: %d != %d",
712 			sz, frame->f_stackadj);
713 #endif
714 
715 	if (tuc.uc_mc.mc_version != LINUX_MCONTEXT_VERSION)
716 		goto bad;
717 
718 	/* Restore signal stack. */
719 	p->p_sigctx.ps_sigstk.ss_flags =
720 		(p->p_sigctx.ps_sigstk.ss_flags & ~SS_ONSTACK) |
721 		(tuc.uc_stack.ss_flags & LINUX_SS_ONSTACK ? SS_ONSTACK : 0);
722 
723 	/* Restore signal mask. */
724 	linux_to_native_sigset(&mask, &tuc.uc_sigmask);
725 	(void) sigprocmask1(p, SIG_SETMASK, &mask, 0);
726 
727 	/*
728 	 * Restore the user supplied information.
729 	 */
730 	bcopy(tuc.uc_mc.mc_gregs.gr_regs, frame->f_regs, sizeof(u_int)*16);
731 	frame->f_pc = tuc.uc_mc.mc_gregs.gr_pc;
732 	/* Privileged bits of  sr  are silently ignored on Linux/m68k. */
733 	frame->f_sr = tuc.uc_mc.mc_gregs.gr_sr & ~(PSL_MBZ|PSL_IPL|PSL_S);
734 
735 	/*
736 	 * Restore long stack frames.  Note that we do not copy
737 	 * back the saved SR or PC, they were picked up above from
738 	 * the ucontext structure.
739 	 */
740 	if (tuc.uc_ss.ss_format) {
741 		frame->f_format = tuc.uc_ss.ss_format;
742 		frame->f_vector = tuc.uc_ss.ss_vector;
743 		if (frame->f_stackadj < sz)	/* just in case... */
744 			goto bad;
745 		frame->f_stackadj -= sz;
746 		bcopy(&tuc.uc_ss.ss_frame, &frame->F_u, sz);
747 #ifdef DEBUG
748 		if (sigdebug & SDB_FOLLOW)
749 			printf("linux_sys_rt_sigreturn(%d): copy in %d of frame type %d\n",
750 			       p->p_pid, sz, tuc.uc_ss.ss_format);
751 #endif
752 	}
753 
754 	/*
755 	 * Finally we restore the original FP context.
756 	 */
757 	switch (fputype) {
758 	case FPU_NONE:
759 		break;
760 #ifdef M68060
761 	case FPU_68060:
762 		if (((struct fpframe060*)&tuc.uc_ss.ss_fpstate.FPF_u1)
763 					->fpf6_frmfmt != FPF6_FMT_NULL) {
764 			/*
765 			 * On 060,  "fmovem <ea>,fpcr/fpsr/fpi"  is
766 			 * emulated by software and slow.
767 			 */
768 			asm("fmovem %0,%%fpcr; fmovem %1,%%fpsr; fmovem %2,%%fpi"::
769 				"m" (tuc.uc_mc.mc_fpregs.fpr_fpcr),
770 				"m" (tuc.uc_mc.mc_fpregs.fpr_fpsr),
771 				"m" (tuc.uc_mc.mc_fpregs.fpr_fpiar));
772 			asm("fmovem %0,%%fp0-%%fp1" : :
773 				"m" (*tuc.uc_mc.mc_fpregs.fpr_regs));
774 		}
775 		asm("frestore %0" : : "m" (tuc.uc_ss.ss_fpstate.FPF_u1));
776 		break;
777 #endif
778 	default:
779 		if (tuc.uc_ss.ss_fpstate.fpf_version) {
780 			asm("fmovem %0,%%fpcr/%%fpsr/%%fpi; fmovem %1,%%fp0-%%fp1"::
781 				"m" (tuc.uc_mc.mc_fpregs.fpr_fpcr),
782 				"m" (*tuc.uc_mc.mc_fpregs.fpr_regs));
783 		}
784 		asm("frestore %0" : : "m" (tuc.uc_ss.ss_fpstate.FPF_u1));
785 		break;
786 	}
787 
788 #ifdef DEBUG
789 	if ((sigdebug & SDB_FPSTATE) && *(char *)&tuc.uc_ss.ss_fpstate)
790 		printf("linux_rt_sigreturn(%d): copied in FP state (%x) at %p\n",
791 		       p->p_pid, *(u_int *)&tuc.uc_ss.ss_fpstate,
792 		       &tuc.uc_ss.ss_fpstate);
793 	if ((sigdebug & SDB_FOLLOW) ||
794 	    ((sigdebug & SDB_KSTACK) && p->p_pid == sigpid))
795 		printf("linux_rt_sigreturn(%d): returns\n", p->p_pid);
796 #endif
797 
798 	return EJUSTRETURN;
799 }
800 
801 /*
802  * MPU cache operation of Linux/m68k,
803  * mainly used for dynamic linking.
804  */
805 
806 /* scope */
807 #define LINUX_FLUSH_SCOPE_LINE	1	/* a cache line */
808 #define LINUX_FLUSH_SCOPE_PAGE	2	/* a page */
809 #define LINUX_FLUSH_SCOPE_ALL	3	/* the whole cache */
810 /* cache */
811 #define LINUX_FLUSH_CACHE_DATA	1	/* flush and purge data cache */
812 #define LINUX_FLUSH_CACHE_INSN	2	/* purge instruction cache */
813 #define LINUX_FLUSH_CACHE_BOTH	3	/* both */
814 
815 /* ARGSUSED */
816 int
817 linux_sys_cacheflush(p, v, retval)
818 	struct proc *p;
819 	void *v;
820 	register_t *retval;
821 {
822 	struct linux_sys_cacheflush_args /* {
823 		syscallarg(unsigned long)	addr;
824 		syscallarg(int)			scope;
825 		syscallarg(int)			cache;
826 		syscallarg(unsigned long)	len;
827 	} */ *uap = v;
828 	int scope, cache;
829 	vaddr_t addr;
830 	int len;
831 	int error;
832 
833 	scope = SCARG(uap, scope);
834 	cache = SCARG(uap, cache);
835 
836 	if (scope < LINUX_FLUSH_SCOPE_LINE || scope > LINUX_FLUSH_SCOPE_ALL
837 				|| cache & ~LINUX_FLUSH_CACHE_BOTH)
838 		return EINVAL;
839 
840 #if defined(M68040) || defined(M68060)
841 	addr = (vaddr_t) SCARG(uap, addr);
842 	len = (int) SCARG(uap, len);
843 #else
844 	/*
845 	 * We always flush entire cache on 68020/030
846 	 * and these values are not used afterwards.
847 	 */
848 	addr = 0;
849 	len = 0;
850 #endif
851 
852 	/*
853 	 * LINUX_FLUSH_SCOPE_ALL (flush whole cache) is limited to super users.
854 	 */
855 	if (scope == LINUX_FLUSH_SCOPE_ALL) {
856 		if ((error = suser(p->p_ucred, &p->p_acflag)) != 0)
857 			return error;
858 #if defined(M68040) || defined(M68060)
859 		/* entire cache */
860 		len = INT_MAX;
861 #endif
862 	}
863 
864 	error = 0;
865 	if (cache & LINUX_FLUSH_CACHE_DATA)
866 		if ((error = cachectl1(CC_EXTPURGE|CC_PURGE, addr, len, p)) !=0)
867 			return error;
868 	if (cache & LINUX_FLUSH_CACHE_INSN)
869 		error = cachectl1(CC_EXTPURGE|CC_IPURGE, addr, len, p);
870 
871 	return error;
872 }
873 
874 /*
875  * Convert NetBSD's devices to Linux's.
876  */
877 dev_t
878 linux_fakedev(dev, raw)
879 	dev_t dev;
880 	int raw;
881 {
882 
883 	/* do nothing for now */
884 	return dev;
885 }
886 
887 /*
888  * We come here in a last attempt to satisfy a Linux ioctl() call.
889  */
890 int
891 linux_machdepioctl(p, v, retval)
892 	struct proc *p;
893 	void *v;
894 	register_t *retval;
895 {
896 	struct linux_sys_ioctl_args /* {
897 		syscallarg(int) fd;
898 		syscallarg(u_long) com;
899 		syscallarg(caddr_t) data;
900 	} */ *uap = v;
901 	struct sys_ioctl_args bia;
902 	u_long com;
903 
904 	SCARG(&bia, fd) = SCARG(uap, fd);
905 	SCARG(&bia, data) = SCARG(uap, data);
906 	com = SCARG(uap, com);
907 
908 	switch (com) {
909 
910 	/* do nothing for now */
911 
912 	default:
913 		printf("linux_machdepioctl: invalid ioctl %08lx\n", com);
914 		return EINVAL;
915 	}
916 	SCARG(&bia, com) = com;
917 	return sys_ioctl(p, &bia, retval);
918 }
919