xref: /linux/arch/m68k/kernel/signal.c (revision 5148fa52a12fa1b97c730b2fe321f2aad7ea041c)
1 /*
2  *  linux/arch/m68k/kernel/signal.c
3  *
4  *  Copyright (C) 1991, 1992  Linus Torvalds
5  *
6  * This file is subject to the terms and conditions of the GNU General Public
7  * License.  See the file COPYING in the main directory of this archive
8  * for more details.
9  */
10 
11 /*
12  * Linux/m68k support by Hamish Macdonald
13  *
14  * 68060 fixes by Jesper Skov
15  *
16  * 1997-12-01  Modified for POSIX.1b signals by Andreas Schwab
17  *
18  * mathemu support by Roman Zippel
19  *  (Note: fpstate in the signal context is completely ignored for the emulator
20  *         and the internal floating point format is put on stack)
21  */
22 
23 /*
24  * ++roman (07/09/96): implemented signal stacks (specially for tosemu on
25  * Atari :-) Current limitation: Only one sigstack can be active at one time.
26  * If a second signal with SA_ONSTACK set arrives while working on a sigstack,
27  * SA_ONSTACK is ignored. This behaviour avoids lots of trouble with nested
28  * signal handlers!
29  */
30 
31 #include <linux/sched.h>
32 #include <linux/mm.h>
33 #include <linux/kernel.h>
34 #include <linux/signal.h>
35 #include <linux/syscalls.h>
36 #include <linux/errno.h>
37 #include <linux/wait.h>
38 #include <linux/ptrace.h>
39 #include <linux/unistd.h>
40 #include <linux/stddef.h>
41 #include <linux/highuid.h>
42 #include <linux/personality.h>
43 #include <linux/tty.h>
44 #include <linux/binfmts.h>
45 #include <linux/module.h>
46 
47 #include <asm/setup.h>
48 #include <asm/uaccess.h>
49 #include <asm/pgtable.h>
50 #include <asm/traps.h>
51 #include <asm/ucontext.h>
52 
53 #define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP)))
54 
55 #ifdef CONFIG_MMU
56 
57 /*
58  * Handle the slight differences in classic 68k and ColdFire trap frames.
59  */
60 #ifdef CONFIG_COLDFIRE
61 #define	FORMAT		4
62 #define	FMT4SIZE	0
63 #else
64 #define	FORMAT		0
65 #define	FMT4SIZE	sizeof(((struct frame *)0)->un.fmt4)
66 #endif
67 
68 static const int frame_size_change[16] = {
69   [1]	= -1, /* sizeof(((struct frame *)0)->un.fmt1), */
70   [2]	= sizeof(((struct frame *)0)->un.fmt2),
71   [3]	= sizeof(((struct frame *)0)->un.fmt3),
72   [4]	= FMT4SIZE,
73   [5]	= -1, /* sizeof(((struct frame *)0)->un.fmt5), */
74   [6]	= -1, /* sizeof(((struct frame *)0)->un.fmt6), */
75   [7]	= sizeof(((struct frame *)0)->un.fmt7),
76   [8]	= -1, /* sizeof(((struct frame *)0)->un.fmt8), */
77   [9]	= sizeof(((struct frame *)0)->un.fmt9),
78   [10]	= sizeof(((struct frame *)0)->un.fmta),
79   [11]	= sizeof(((struct frame *)0)->un.fmtb),
80   [12]	= -1, /* sizeof(((struct frame *)0)->un.fmtc), */
81   [13]	= -1, /* sizeof(((struct frame *)0)->un.fmtd), */
82   [14]	= -1, /* sizeof(((struct frame *)0)->un.fmte), */
83   [15]	= -1, /* sizeof(((struct frame *)0)->un.fmtf), */
84 };
85 
86 static inline int frame_extra_sizes(int f)
87 {
88 	return frame_size_change[f];
89 }
90 
91 int handle_kernel_fault(struct pt_regs *regs)
92 {
93 	const struct exception_table_entry *fixup;
94 	struct pt_regs *tregs;
95 
96 	/* Are we prepared to handle this kernel fault? */
97 	fixup = search_exception_tables(regs->pc);
98 	if (!fixup)
99 		return 0;
100 
101 	/* Create a new four word stack frame, discarding the old one. */
102 	regs->stkadj = frame_extra_sizes(regs->format);
103 	tregs =	(struct pt_regs *)((long)regs + regs->stkadj);
104 	tregs->vector = regs->vector;
105 	tregs->format = FORMAT;
106 	tregs->pc = fixup->fixup;
107 	tregs->sr = regs->sr;
108 
109 	return 1;
110 }
111 
112 void ptrace_signal_deliver(struct pt_regs *regs, void *cookie)
113 {
114 	if (regs->orig_d0 < 0)
115 		return;
116 	switch (regs->d0) {
117 	case -ERESTARTNOHAND:
118 	case -ERESTARTSYS:
119 	case -ERESTARTNOINTR:
120 		regs->d0 = regs->orig_d0;
121 		regs->orig_d0 = -1;
122 		regs->pc -= 2;
123 		break;
124 	}
125 }
126 
127 static inline void push_cache (unsigned long vaddr)
128 {
129 	/*
130 	 * Using the old cache_push_v() was really a big waste.
131 	 *
132 	 * What we are trying to do is to flush 8 bytes to ram.
133 	 * Flushing 2 cache lines of 16 bytes is much cheaper than
134 	 * flushing 1 or 2 pages, as previously done in
135 	 * cache_push_v().
136 	 *                                                     Jes
137 	 */
138 	if (CPU_IS_040) {
139 		unsigned long temp;
140 
141 		__asm__ __volatile__ (".chip 68040\n\t"
142 				      "nop\n\t"
143 				      "ptestr (%1)\n\t"
144 				      "movec %%mmusr,%0\n\t"
145 				      ".chip 68k"
146 				      : "=r" (temp)
147 				      : "a" (vaddr));
148 
149 		temp &= PAGE_MASK;
150 		temp |= vaddr & ~PAGE_MASK;
151 
152 		__asm__ __volatile__ (".chip 68040\n\t"
153 				      "nop\n\t"
154 				      "cpushl %%bc,(%0)\n\t"
155 				      ".chip 68k"
156 				      : : "a" (temp));
157 	}
158 	else if (CPU_IS_060) {
159 		unsigned long temp;
160 		__asm__ __volatile__ (".chip 68060\n\t"
161 				      "plpar (%0)\n\t"
162 				      ".chip 68k"
163 				      : "=a" (temp)
164 				      : "0" (vaddr));
165 		__asm__ __volatile__ (".chip 68060\n\t"
166 				      "cpushl %%bc,(%0)\n\t"
167 				      ".chip 68k"
168 				      : : "a" (temp));
169 	} else if (!CPU_IS_COLDFIRE) {
170 		/*
171 		 * 68030/68020 have no writeback cache;
172 		 * still need to clear icache.
173 		 * Note that vaddr is guaranteed to be long word aligned.
174 		 */
175 		unsigned long temp;
176 		asm volatile ("movec %%cacr,%0" : "=r" (temp));
177 		temp += 4;
178 		asm volatile ("movec %0,%%caar\n\t"
179 			      "movec %1,%%cacr"
180 			      : : "r" (vaddr), "r" (temp));
181 		asm volatile ("movec %0,%%caar\n\t"
182 			      "movec %1,%%cacr"
183 			      : : "r" (vaddr + 4), "r" (temp));
184 	}
185 }
186 
187 static inline void adjustformat(struct pt_regs *regs)
188 {
189 }
190 
191 static inline void save_a5_state(struct sigcontext *sc, struct pt_regs *regs)
192 {
193 }
194 
195 #else /* CONFIG_MMU */
196 
197 void ret_from_user_signal(void);
198 void ret_from_user_rt_signal(void);
199 
200 static inline int frame_extra_sizes(int f)
201 {
202 	/* No frame size adjustments required on non-MMU CPUs */
203 	return 0;
204 }
205 
206 static inline void adjustformat(struct pt_regs *regs)
207 {
208 	((struct switch_stack *)regs - 1)->a5 = current->mm->start_data;
209 	/*
210 	 * set format byte to make stack appear modulo 4, which it will
211 	 * be when doing the rte
212 	 */
213 	regs->format = 0x4;
214 }
215 
216 static inline void save_a5_state(struct sigcontext *sc, struct pt_regs *regs)
217 {
218 	sc->sc_a5 = ((struct switch_stack *)regs - 1)->a5;
219 }
220 
221 static inline void push_cache(unsigned long vaddr)
222 {
223 }
224 
225 #endif /* CONFIG_MMU */
226 
227 /*
228  * Atomically swap in the new signal mask, and wait for a signal.
229  */
230 asmlinkage int
231 sys_sigsuspend(int unused0, int unused1, old_sigset_t mask)
232 {
233 	mask &= _BLOCKABLE;
234 	spin_lock_irq(&current->sighand->siglock);
235 	current->saved_sigmask = current->blocked;
236 	siginitset(&current->blocked, mask);
237 	recalc_sigpending();
238 	spin_unlock_irq(&current->sighand->siglock);
239 
240 	current->state = TASK_INTERRUPTIBLE;
241 	schedule();
242 	set_restore_sigmask();
243 
244 	return -ERESTARTNOHAND;
245 }
246 
247 asmlinkage int
248 sys_sigaction(int sig, const struct old_sigaction __user *act,
249 	      struct old_sigaction __user *oact)
250 {
251 	struct k_sigaction new_ka, old_ka;
252 	int ret;
253 
254 	if (act) {
255 		old_sigset_t mask;
256 		if (!access_ok(VERIFY_READ, act, sizeof(*act)) ||
257 		    __get_user(new_ka.sa.sa_handler, &act->sa_handler) ||
258 		    __get_user(new_ka.sa.sa_restorer, &act->sa_restorer) ||
259 		    __get_user(new_ka.sa.sa_flags, &act->sa_flags) ||
260 		    __get_user(mask, &act->sa_mask))
261 			return -EFAULT;
262 		siginitset(&new_ka.sa.sa_mask, mask);
263 	}
264 
265 	ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL);
266 
267 	if (!ret && oact) {
268 		if (!access_ok(VERIFY_WRITE, oact, sizeof(*oact)) ||
269 		    __put_user(old_ka.sa.sa_handler, &oact->sa_handler) ||
270 		    __put_user(old_ka.sa.sa_restorer, &oact->sa_restorer) ||
271 		    __put_user(old_ka.sa.sa_flags, &oact->sa_flags) ||
272 		    __put_user(old_ka.sa.sa_mask.sig[0], &oact->sa_mask))
273 			return -EFAULT;
274 	}
275 
276 	return ret;
277 }
278 
279 asmlinkage int
280 sys_sigaltstack(const stack_t __user *uss, stack_t __user *uoss)
281 {
282 	return do_sigaltstack(uss, uoss, rdusp());
283 }
284 
285 
286 /*
287  * Do a signal return; undo the signal stack.
288  *
289  * Keep the return code on the stack quadword aligned!
290  * That makes the cache flush below easier.
291  */
292 
293 struct sigframe
294 {
295 	char __user *pretcode;
296 	int sig;
297 	int code;
298 	struct sigcontext __user *psc;
299 	char retcode[8];
300 	unsigned long extramask[_NSIG_WORDS-1];
301 	struct sigcontext sc;
302 };
303 
304 struct rt_sigframe
305 {
306 	char __user *pretcode;
307 	int sig;
308 	struct siginfo __user *pinfo;
309 	void __user *puc;
310 	char retcode[8];
311 	struct siginfo info;
312 	struct ucontext uc;
313 };
314 
315 #define FPCONTEXT_SIZE	216
316 #define uc_fpstate	uc_filler[0]
317 #define uc_formatvec	uc_filler[FPCONTEXT_SIZE/4]
318 #define uc_extra	uc_filler[FPCONTEXT_SIZE/4+1]
319 
320 #ifdef CONFIG_FPU
321 
322 static unsigned char fpu_version;	/* version number of fpu, set by setup_frame */
323 
324 static inline int restore_fpu_state(struct sigcontext *sc)
325 {
326 	int err = 1;
327 
328 	if (FPU_IS_EMU) {
329 	    /* restore registers */
330 	    memcpy(current->thread.fpcntl, sc->sc_fpcntl, 12);
331 	    memcpy(current->thread.fp, sc->sc_fpregs, 24);
332 	    return 0;
333 	}
334 
335 	if (CPU_IS_060 ? sc->sc_fpstate[2] : sc->sc_fpstate[0]) {
336 	    /* Verify the frame format.  */
337 	    if (!(CPU_IS_060 || CPU_IS_COLDFIRE) &&
338 		 (sc->sc_fpstate[0] != fpu_version))
339 		goto out;
340 	    if (CPU_IS_020_OR_030) {
341 		if (m68k_fputype & FPU_68881 &&
342 		    !(sc->sc_fpstate[1] == 0x18 || sc->sc_fpstate[1] == 0xb4))
343 		    goto out;
344 		if (m68k_fputype & FPU_68882 &&
345 		    !(sc->sc_fpstate[1] == 0x38 || sc->sc_fpstate[1] == 0xd4))
346 		    goto out;
347 	    } else if (CPU_IS_040) {
348 		if (!(sc->sc_fpstate[1] == 0x00 ||
349                       sc->sc_fpstate[1] == 0x28 ||
350                       sc->sc_fpstate[1] == 0x60))
351 		    goto out;
352 	    } else if (CPU_IS_060) {
353 		if (!(sc->sc_fpstate[3] == 0x00 ||
354                       sc->sc_fpstate[3] == 0x60 ||
355 		      sc->sc_fpstate[3] == 0xe0))
356 		    goto out;
357 	    } else if (CPU_IS_COLDFIRE) {
358 		if (!(sc->sc_fpstate[0] == 0x00 ||
359 		      sc->sc_fpstate[0] == 0x05 ||
360 		      sc->sc_fpstate[0] == 0xe5))
361 		    goto out;
362 	    } else
363 		goto out;
364 
365 	    if (CPU_IS_COLDFIRE) {
366 		__asm__ volatile ("fmovemd %0,%%fp0-%%fp1\n\t"
367 				  "fmovel %1,%%fpcr\n\t"
368 				  "fmovel %2,%%fpsr\n\t"
369 				  "fmovel %3,%%fpiar"
370 				  : /* no outputs */
371 				  : "m" (sc->sc_fpregs[0]),
372 				    "m" (sc->sc_fpcntl[0]),
373 				    "m" (sc->sc_fpcntl[1]),
374 				    "m" (sc->sc_fpcntl[2]));
375 	    } else {
376 		__asm__ volatile (".chip 68k/68881\n\t"
377 				  "fmovemx %0,%%fp0-%%fp1\n\t"
378 				  "fmoveml %1,%%fpcr/%%fpsr/%%fpiar\n\t"
379 				  ".chip 68k"
380 				  : /* no outputs */
381 				  : "m" (*sc->sc_fpregs),
382 				    "m" (*sc->sc_fpcntl));
383 	    }
384 	}
385 
386 	if (CPU_IS_COLDFIRE) {
387 		__asm__ volatile ("frestore %0" : : "m" (*sc->sc_fpstate));
388 	} else {
389 		__asm__ volatile (".chip 68k/68881\n\t"
390 				  "frestore %0\n\t"
391 				  ".chip 68k"
392 				  : : "m" (*sc->sc_fpstate));
393 	}
394 	err = 0;
395 
396 out:
397 	return err;
398 }
399 
400 static inline int rt_restore_fpu_state(struct ucontext __user *uc)
401 {
402 	unsigned char fpstate[FPCONTEXT_SIZE];
403 	int context_size = CPU_IS_060 ? 8 : (CPU_IS_COLDFIRE ? 12 : 0);
404 	fpregset_t fpregs;
405 	int err = 1;
406 
407 	if (FPU_IS_EMU) {
408 		/* restore fpu control register */
409 		if (__copy_from_user(current->thread.fpcntl,
410 				uc->uc_mcontext.fpregs.f_fpcntl, 12))
411 			goto out;
412 		/* restore all other fpu register */
413 		if (__copy_from_user(current->thread.fp,
414 				uc->uc_mcontext.fpregs.f_fpregs, 96))
415 			goto out;
416 		return 0;
417 	}
418 
419 	if (__get_user(*(long *)fpstate, (long __user *)&uc->uc_fpstate))
420 		goto out;
421 	if (CPU_IS_060 ? fpstate[2] : fpstate[0]) {
422 		if (!(CPU_IS_060 || CPU_IS_COLDFIRE))
423 			context_size = fpstate[1];
424 		/* Verify the frame format.  */
425 		if (!(CPU_IS_060 || CPU_IS_COLDFIRE) &&
426 		     (fpstate[0] != fpu_version))
427 			goto out;
428 		if (CPU_IS_020_OR_030) {
429 			if (m68k_fputype & FPU_68881 &&
430 			    !(context_size == 0x18 || context_size == 0xb4))
431 				goto out;
432 			if (m68k_fputype & FPU_68882 &&
433 			    !(context_size == 0x38 || context_size == 0xd4))
434 				goto out;
435 		} else if (CPU_IS_040) {
436 			if (!(context_size == 0x00 ||
437 			      context_size == 0x28 ||
438 			      context_size == 0x60))
439 				goto out;
440 		} else if (CPU_IS_060) {
441 			if (!(fpstate[3] == 0x00 ||
442 			      fpstate[3] == 0x60 ||
443 			      fpstate[3] == 0xe0))
444 				goto out;
445 		} else if (CPU_IS_COLDFIRE) {
446 			if (!(fpstate[3] == 0x00 ||
447 			      fpstate[3] == 0x05 ||
448 			      fpstate[3] == 0xe5))
449 				goto out;
450 		} else
451 			goto out;
452 		if (__copy_from_user(&fpregs, &uc->uc_mcontext.fpregs,
453 				     sizeof(fpregs)))
454 			goto out;
455 
456 		if (CPU_IS_COLDFIRE) {
457 			__asm__ volatile ("fmovemd %0,%%fp0-%%fp7\n\t"
458 					  "fmovel %1,%%fpcr\n\t"
459 					  "fmovel %2,%%fpsr\n\t"
460 					  "fmovel %3,%%fpiar"
461 					  : /* no outputs */
462 					  : "m" (fpregs.f_fpregs[0]),
463 					    "m" (fpregs.f_fpcntl[0]),
464 					    "m" (fpregs.f_fpcntl[1]),
465 					    "m" (fpregs.f_fpcntl[2]));
466 		} else {
467 			__asm__ volatile (".chip 68k/68881\n\t"
468 					  "fmovemx %0,%%fp0-%%fp7\n\t"
469 					  "fmoveml %1,%%fpcr/%%fpsr/%%fpiar\n\t"
470 					  ".chip 68k"
471 					  : /* no outputs */
472 					  : "m" (*fpregs.f_fpregs),
473 					    "m" (*fpregs.f_fpcntl));
474 		}
475 	}
476 	if (context_size &&
477 	    __copy_from_user(fpstate + 4, (long __user *)&uc->uc_fpstate + 1,
478 			     context_size))
479 		goto out;
480 
481 	if (CPU_IS_COLDFIRE) {
482 		__asm__ volatile ("frestore %0" : : "m" (*fpstate));
483 	} else {
484 		__asm__ volatile (".chip 68k/68881\n\t"
485 				  "frestore %0\n\t"
486 				  ".chip 68k"
487 				  : : "m" (*fpstate));
488 	}
489 	err = 0;
490 
491 out:
492 	return err;
493 }
494 
495 /*
496  * Set up a signal frame.
497  */
498 static inline void save_fpu_state(struct sigcontext *sc, struct pt_regs *regs)
499 {
500 	if (FPU_IS_EMU) {
501 		/* save registers */
502 		memcpy(sc->sc_fpcntl, current->thread.fpcntl, 12);
503 		memcpy(sc->sc_fpregs, current->thread.fp, 24);
504 		return;
505 	}
506 
507 	if (CPU_IS_COLDFIRE) {
508 		__asm__ volatile ("fsave %0"
509 				  : : "m" (*sc->sc_fpstate) : "memory");
510 	} else {
511 		__asm__ volatile (".chip 68k/68881\n\t"
512 				  "fsave %0\n\t"
513 				  ".chip 68k"
514 				  : : "m" (*sc->sc_fpstate) : "memory");
515 	}
516 
517 	if (CPU_IS_060 ? sc->sc_fpstate[2] : sc->sc_fpstate[0]) {
518 		fpu_version = sc->sc_fpstate[0];
519 		if (CPU_IS_020_OR_030 &&
520 		    regs->vector >= (VEC_FPBRUC * 4) &&
521 		    regs->vector <= (VEC_FPNAN * 4)) {
522 			/* Clear pending exception in 68882 idle frame */
523 			if (*(unsigned short *) sc->sc_fpstate == 0x1f38)
524 				sc->sc_fpstate[0x38] |= 1 << 3;
525 		}
526 
527 		if (CPU_IS_COLDFIRE) {
528 			__asm__ volatile ("fmovemd %%fp0-%%fp1,%0\n\t"
529 					  "fmovel %%fpcr,%1\n\t"
530 					  "fmovel %%fpsr,%2\n\t"
531 					  "fmovel %%fpiar,%3"
532 					  : "=m" (sc->sc_fpregs[0]),
533 					    "=m" (sc->sc_fpcntl[0]),
534 					    "=m" (sc->sc_fpcntl[1]),
535 					    "=m" (sc->sc_fpcntl[2])
536 					  : /* no inputs */
537 					  : "memory");
538 		} else {
539 			__asm__ volatile (".chip 68k/68881\n\t"
540 					  "fmovemx %%fp0-%%fp1,%0\n\t"
541 					  "fmoveml %%fpcr/%%fpsr/%%fpiar,%1\n\t"
542 					  ".chip 68k"
543 					  : "=m" (*sc->sc_fpregs),
544 					    "=m" (*sc->sc_fpcntl)
545 					  : /* no inputs */
546 					  : "memory");
547 		}
548 	}
549 }
550 
551 static inline int rt_save_fpu_state(struct ucontext __user *uc, struct pt_regs *regs)
552 {
553 	unsigned char fpstate[FPCONTEXT_SIZE];
554 	int context_size = CPU_IS_060 ? 8 : (CPU_IS_COLDFIRE ? 12 : 0);
555 	int err = 0;
556 
557 	if (FPU_IS_EMU) {
558 		/* save fpu control register */
559 		err |= copy_to_user(uc->uc_mcontext.fpregs.f_fpcntl,
560 				current->thread.fpcntl, 12);
561 		/* save all other fpu register */
562 		err |= copy_to_user(uc->uc_mcontext.fpregs.f_fpregs,
563 				current->thread.fp, 96);
564 		return err;
565 	}
566 
567 	if (CPU_IS_COLDFIRE) {
568 		__asm__ volatile ("fsave %0" : : "m" (*fpstate) : "memory");
569 	} else {
570 		__asm__ volatile (".chip 68k/68881\n\t"
571 				  "fsave %0\n\t"
572 				  ".chip 68k"
573 				  : : "m" (*fpstate) : "memory");
574 	}
575 
576 	err |= __put_user(*(long *)fpstate, (long __user *)&uc->uc_fpstate);
577 	if (CPU_IS_060 ? fpstate[2] : fpstate[0]) {
578 		fpregset_t fpregs;
579 		if (!(CPU_IS_060 || CPU_IS_COLDFIRE))
580 			context_size = fpstate[1];
581 		fpu_version = fpstate[0];
582 		if (CPU_IS_020_OR_030 &&
583 		    regs->vector >= (VEC_FPBRUC * 4) &&
584 		    regs->vector <= (VEC_FPNAN * 4)) {
585 			/* Clear pending exception in 68882 idle frame */
586 			if (*(unsigned short *) fpstate == 0x1f38)
587 				fpstate[0x38] |= 1 << 3;
588 		}
589 		if (CPU_IS_COLDFIRE) {
590 			__asm__ volatile ("fmovemd %%fp0-%%fp7,%0\n\t"
591 					  "fmovel %%fpcr,%1\n\t"
592 					  "fmovel %%fpsr,%2\n\t"
593 					  "fmovel %%fpiar,%3"
594 					  : "=m" (fpregs.f_fpregs[0]),
595 					    "=m" (fpregs.f_fpcntl[0]),
596 					    "=m" (fpregs.f_fpcntl[1]),
597 					    "=m" (fpregs.f_fpcntl[2])
598 					  : /* no inputs */
599 					  : "memory");
600 		} else {
601 			__asm__ volatile (".chip 68k/68881\n\t"
602 					  "fmovemx %%fp0-%%fp7,%0\n\t"
603 					  "fmoveml %%fpcr/%%fpsr/%%fpiar,%1\n\t"
604 					  ".chip 68k"
605 					  : "=m" (*fpregs.f_fpregs),
606 					    "=m" (*fpregs.f_fpcntl)
607 					  : /* no inputs */
608 					  : "memory");
609 		}
610 		err |= copy_to_user(&uc->uc_mcontext.fpregs, &fpregs,
611 				    sizeof(fpregs));
612 	}
613 	if (context_size)
614 		err |= copy_to_user((long __user *)&uc->uc_fpstate + 1, fpstate + 4,
615 				    context_size);
616 	return err;
617 }
618 
619 #else /* CONFIG_FPU */
620 
621 /*
622  * For the case with no FPU configured these all do nothing.
623  */
624 static inline int restore_fpu_state(struct sigcontext *sc)
625 {
626 	return 0;
627 }
628 
629 static inline int rt_restore_fpu_state(struct ucontext __user *uc)
630 {
631 	return 0;
632 }
633 
634 static inline void save_fpu_state(struct sigcontext *sc, struct pt_regs *regs)
635 {
636 }
637 
638 static inline int rt_save_fpu_state(struct ucontext __user *uc, struct pt_regs *regs)
639 {
640 	return 0;
641 }
642 
643 #endif /* CONFIG_FPU */
644 
645 static int mangle_kernel_stack(struct pt_regs *regs, int formatvec,
646 			       void __user *fp)
647 {
648 	int fsize = frame_extra_sizes(formatvec >> 12);
649 	if (fsize < 0) {
650 		/*
651 		 * user process trying to return with weird frame format
652 		 */
653 #ifdef DEBUG
654 		printk("user process returning with weird frame format\n");
655 #endif
656 		return 1;
657 	}
658 	if (!fsize) {
659 		regs->format = formatvec >> 12;
660 		regs->vector = formatvec & 0xfff;
661 	} else {
662 		struct switch_stack *sw = (struct switch_stack *)regs - 1;
663 		unsigned long buf[fsize / 2]; /* yes, twice as much */
664 
665 		/* that'll make sure that expansion won't crap over data */
666 		if (copy_from_user(buf + fsize / 4, fp, fsize))
667 			return 1;
668 
669 		/* point of no return */
670 		regs->format = formatvec >> 12;
671 		regs->vector = formatvec & 0xfff;
672 #define frame_offset (sizeof(struct pt_regs)+sizeof(struct switch_stack))
673 		__asm__ __volatile__ (
674 #ifdef CONFIG_COLDFIRE
675 			 "   movel %0,%/sp\n\t"
676 			 "   bra ret_from_signal\n"
677 #else
678 			 "   movel %0,%/a0\n\t"
679 			 "   subl %1,%/a0\n\t"     /* make room on stack */
680 			 "   movel %/a0,%/sp\n\t"  /* set stack pointer */
681 			 /* move switch_stack and pt_regs */
682 			 "1: movel %0@+,%/a0@+\n\t"
683 			 "   dbra %2,1b\n\t"
684 			 "   lea %/sp@(%c3),%/a0\n\t" /* add offset of fmt */
685 			 "   lsrl  #2,%1\n\t"
686 			 "   subql #1,%1\n\t"
687 			 /* copy to the gap we'd made */
688 			 "2: movel %4@+,%/a0@+\n\t"
689 			 "   dbra %1,2b\n\t"
690 			 "   bral ret_from_signal\n"
691 #endif
692 			 : /* no outputs, it doesn't ever return */
693 			 : "a" (sw), "d" (fsize), "d" (frame_offset/4-1),
694 			   "n" (frame_offset), "a" (buf + fsize/4)
695 			 : "a0");
696 #undef frame_offset
697 	}
698 	return 0;
699 }
700 
701 static inline int
702 restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *usc, void __user *fp)
703 {
704 	int formatvec;
705 	struct sigcontext context;
706 	int err = 0;
707 
708 	/* Always make any pending restarted system calls return -EINTR */
709 	current_thread_info()->restart_block.fn = do_no_restart_syscall;
710 
711 	/* get previous context */
712 	if (copy_from_user(&context, usc, sizeof(context)))
713 		goto badframe;
714 
715 	/* restore passed registers */
716 	regs->d0 = context.sc_d0;
717 	regs->d1 = context.sc_d1;
718 	regs->a0 = context.sc_a0;
719 	regs->a1 = context.sc_a1;
720 	regs->sr = (regs->sr & 0xff00) | (context.sc_sr & 0xff);
721 	regs->pc = context.sc_pc;
722 	regs->orig_d0 = -1;		/* disable syscall checks */
723 	wrusp(context.sc_usp);
724 	formatvec = context.sc_formatvec;
725 
726 	err = restore_fpu_state(&context);
727 
728 	if (err || mangle_kernel_stack(regs, formatvec, fp))
729 		goto badframe;
730 
731 	return 0;
732 
733 badframe:
734 	return 1;
735 }
736 
737 static inline int
738 rt_restore_ucontext(struct pt_regs *regs, struct switch_stack *sw,
739 		    struct ucontext __user *uc)
740 {
741 	int temp;
742 	greg_t __user *gregs = uc->uc_mcontext.gregs;
743 	unsigned long usp;
744 	int err;
745 
746 	/* Always make any pending restarted system calls return -EINTR */
747 	current_thread_info()->restart_block.fn = do_no_restart_syscall;
748 
749 	err = __get_user(temp, &uc->uc_mcontext.version);
750 	if (temp != MCONTEXT_VERSION)
751 		goto badframe;
752 	/* restore passed registers */
753 	err |= __get_user(regs->d0, &gregs[0]);
754 	err |= __get_user(regs->d1, &gregs[1]);
755 	err |= __get_user(regs->d2, &gregs[2]);
756 	err |= __get_user(regs->d3, &gregs[3]);
757 	err |= __get_user(regs->d4, &gregs[4]);
758 	err |= __get_user(regs->d5, &gregs[5]);
759 	err |= __get_user(sw->d6, &gregs[6]);
760 	err |= __get_user(sw->d7, &gregs[7]);
761 	err |= __get_user(regs->a0, &gregs[8]);
762 	err |= __get_user(regs->a1, &gregs[9]);
763 	err |= __get_user(regs->a2, &gregs[10]);
764 	err |= __get_user(sw->a3, &gregs[11]);
765 	err |= __get_user(sw->a4, &gregs[12]);
766 	err |= __get_user(sw->a5, &gregs[13]);
767 	err |= __get_user(sw->a6, &gregs[14]);
768 	err |= __get_user(usp, &gregs[15]);
769 	wrusp(usp);
770 	err |= __get_user(regs->pc, &gregs[16]);
771 	err |= __get_user(temp, &gregs[17]);
772 	regs->sr = (regs->sr & 0xff00) | (temp & 0xff);
773 	regs->orig_d0 = -1;		/* disable syscall checks */
774 	err |= __get_user(temp, &uc->uc_formatvec);
775 
776 	err |= rt_restore_fpu_state(uc);
777 
778 	if (err || do_sigaltstack(&uc->uc_stack, NULL, usp) == -EFAULT)
779 		goto badframe;
780 
781 	if (mangle_kernel_stack(regs, temp, &uc->uc_extra))
782 		goto badframe;
783 
784 	return 0;
785 
786 badframe:
787 	return 1;
788 }
789 
790 asmlinkage int do_sigreturn(unsigned long __unused)
791 {
792 	struct switch_stack *sw = (struct switch_stack *) &__unused;
793 	struct pt_regs *regs = (struct pt_regs *) (sw + 1);
794 	unsigned long usp = rdusp();
795 	struct sigframe __user *frame = (struct sigframe __user *)(usp - 4);
796 	sigset_t set;
797 
798 	if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
799 		goto badframe;
800 	if (__get_user(set.sig[0], &frame->sc.sc_mask) ||
801 	    (_NSIG_WORDS > 1 &&
802 	     __copy_from_user(&set.sig[1], &frame->extramask,
803 			      sizeof(frame->extramask))))
804 		goto badframe;
805 
806 	sigdelsetmask(&set, ~_BLOCKABLE);
807 	current->blocked = set;
808 	recalc_sigpending();
809 
810 	if (restore_sigcontext(regs, &frame->sc, frame + 1))
811 		goto badframe;
812 	return regs->d0;
813 
814 badframe:
815 	force_sig(SIGSEGV, current);
816 	return 0;
817 }
818 
819 asmlinkage int do_rt_sigreturn(unsigned long __unused)
820 {
821 	struct switch_stack *sw = (struct switch_stack *) &__unused;
822 	struct pt_regs *regs = (struct pt_regs *) (sw + 1);
823 	unsigned long usp = rdusp();
824 	struct rt_sigframe __user *frame = (struct rt_sigframe __user *)(usp - 4);
825 	sigset_t set;
826 
827 	if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
828 		goto badframe;
829 	if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set)))
830 		goto badframe;
831 
832 	sigdelsetmask(&set, ~_BLOCKABLE);
833 	current->blocked = set;
834 	recalc_sigpending();
835 
836 	if (rt_restore_ucontext(regs, sw, &frame->uc))
837 		goto badframe;
838 	return regs->d0;
839 
840 badframe:
841 	force_sig(SIGSEGV, current);
842 	return 0;
843 }
844 
845 static void setup_sigcontext(struct sigcontext *sc, struct pt_regs *regs,
846 			     unsigned long mask)
847 {
848 	sc->sc_mask = mask;
849 	sc->sc_usp = rdusp();
850 	sc->sc_d0 = regs->d0;
851 	sc->sc_d1 = regs->d1;
852 	sc->sc_a0 = regs->a0;
853 	sc->sc_a1 = regs->a1;
854 	sc->sc_sr = regs->sr;
855 	sc->sc_pc = regs->pc;
856 	sc->sc_formatvec = regs->format << 12 | regs->vector;
857 	save_a5_state(sc, regs);
858 	save_fpu_state(sc, regs);
859 }
860 
861 static inline int rt_setup_ucontext(struct ucontext __user *uc, struct pt_regs *regs)
862 {
863 	struct switch_stack *sw = (struct switch_stack *)regs - 1;
864 	greg_t __user *gregs = uc->uc_mcontext.gregs;
865 	int err = 0;
866 
867 	err |= __put_user(MCONTEXT_VERSION, &uc->uc_mcontext.version);
868 	err |= __put_user(regs->d0, &gregs[0]);
869 	err |= __put_user(regs->d1, &gregs[1]);
870 	err |= __put_user(regs->d2, &gregs[2]);
871 	err |= __put_user(regs->d3, &gregs[3]);
872 	err |= __put_user(regs->d4, &gregs[4]);
873 	err |= __put_user(regs->d5, &gregs[5]);
874 	err |= __put_user(sw->d6, &gregs[6]);
875 	err |= __put_user(sw->d7, &gregs[7]);
876 	err |= __put_user(regs->a0, &gregs[8]);
877 	err |= __put_user(regs->a1, &gregs[9]);
878 	err |= __put_user(regs->a2, &gregs[10]);
879 	err |= __put_user(sw->a3, &gregs[11]);
880 	err |= __put_user(sw->a4, &gregs[12]);
881 	err |= __put_user(sw->a5, &gregs[13]);
882 	err |= __put_user(sw->a6, &gregs[14]);
883 	err |= __put_user(rdusp(), &gregs[15]);
884 	err |= __put_user(regs->pc, &gregs[16]);
885 	err |= __put_user(regs->sr, &gregs[17]);
886 	err |= __put_user((regs->format << 12) | regs->vector, &uc->uc_formatvec);
887 	err |= rt_save_fpu_state(uc, regs);
888 	return err;
889 }
890 
891 static inline void __user *
892 get_sigframe(struct k_sigaction *ka, struct pt_regs *regs, size_t frame_size)
893 {
894 	unsigned long usp;
895 
896 	/* Default to using normal stack.  */
897 	usp = rdusp();
898 
899 	/* This is the X/Open sanctioned signal stack switching.  */
900 	if (ka->sa.sa_flags & SA_ONSTACK) {
901 		if (!sas_ss_flags(usp))
902 			usp = current->sas_ss_sp + current->sas_ss_size;
903 	}
904 	return (void __user *)((usp - frame_size) & -8UL);
905 }
906 
907 static int setup_frame (int sig, struct k_sigaction *ka,
908 			 sigset_t *set, struct pt_regs *regs)
909 {
910 	struct sigframe __user *frame;
911 	int fsize = frame_extra_sizes(regs->format);
912 	struct sigcontext context;
913 	int err = 0;
914 
915 	if (fsize < 0) {
916 #ifdef DEBUG
917 		printk ("setup_frame: Unknown frame format %#x\n",
918 			regs->format);
919 #endif
920 		goto give_sigsegv;
921 	}
922 
923 	frame = get_sigframe(ka, regs, sizeof(*frame) + fsize);
924 
925 	if (fsize)
926 		err |= copy_to_user (frame + 1, regs + 1, fsize);
927 
928 	err |= __put_user((current_thread_info()->exec_domain
929 			   && current_thread_info()->exec_domain->signal_invmap
930 			   && sig < 32
931 			   ? current_thread_info()->exec_domain->signal_invmap[sig]
932 			   : sig),
933 			  &frame->sig);
934 
935 	err |= __put_user(regs->vector, &frame->code);
936 	err |= __put_user(&frame->sc, &frame->psc);
937 
938 	if (_NSIG_WORDS > 1)
939 		err |= copy_to_user(frame->extramask, &set->sig[1],
940 				    sizeof(frame->extramask));
941 
942 	setup_sigcontext(&context, regs, set->sig[0]);
943 	err |= copy_to_user (&frame->sc, &context, sizeof(context));
944 
945 	/* Set up to return from userspace.  */
946 #ifdef CONFIG_MMU
947 	err |= __put_user(frame->retcode, &frame->pretcode);
948 	/* moveq #,d0; trap #0 */
949 	err |= __put_user(0x70004e40 + (__NR_sigreturn << 16),
950 			  (long __user *)(frame->retcode));
951 #else
952 	err |= __put_user((void *) ret_from_user_signal, &frame->pretcode);
953 #endif
954 
955 	if (err)
956 		goto give_sigsegv;
957 
958 	push_cache ((unsigned long) &frame->retcode);
959 
960 	/*
961 	 * Set up registers for signal handler.  All the state we are about
962 	 * to destroy is successfully copied to sigframe.
963 	 */
964 	wrusp ((unsigned long) frame);
965 	regs->pc = (unsigned long) ka->sa.sa_handler;
966 	adjustformat(regs);
967 
968 	/*
969 	 * This is subtle; if we build more than one sigframe, all but the
970 	 * first one will see frame format 0 and have fsize == 0, so we won't
971 	 * screw stkadj.
972 	 */
973 	if (fsize)
974 		regs->stkadj = fsize;
975 
976 	/* Prepare to skip over the extra stuff in the exception frame.  */
977 	if (regs->stkadj) {
978 		struct pt_regs *tregs =
979 			(struct pt_regs *)((ulong)regs + regs->stkadj);
980 #ifdef DEBUG
981 		printk("Performing stackadjust=%04x\n", regs->stkadj);
982 #endif
983 		/* This must be copied with decreasing addresses to
984                    handle overlaps.  */
985 		tregs->vector = 0;
986 		tregs->format = 0;
987 		tregs->pc = regs->pc;
988 		tregs->sr = regs->sr;
989 	}
990 	return 0;
991 
992 give_sigsegv:
993 	force_sigsegv(sig, current);
994 	return err;
995 }
996 
997 static int setup_rt_frame (int sig, struct k_sigaction *ka, siginfo_t *info,
998 			    sigset_t *set, struct pt_regs *regs)
999 {
1000 	struct rt_sigframe __user *frame;
1001 	int fsize = frame_extra_sizes(regs->format);
1002 	int err = 0;
1003 
1004 	if (fsize < 0) {
1005 #ifdef DEBUG
1006 		printk ("setup_frame: Unknown frame format %#x\n",
1007 			regs->format);
1008 #endif
1009 		goto give_sigsegv;
1010 	}
1011 
1012 	frame = get_sigframe(ka, regs, sizeof(*frame));
1013 
1014 	if (fsize)
1015 		err |= copy_to_user (&frame->uc.uc_extra, regs + 1, fsize);
1016 
1017 	err |= __put_user((current_thread_info()->exec_domain
1018 			   && current_thread_info()->exec_domain->signal_invmap
1019 			   && sig < 32
1020 			   ? current_thread_info()->exec_domain->signal_invmap[sig]
1021 			   : sig),
1022 			  &frame->sig);
1023 	err |= __put_user(&frame->info, &frame->pinfo);
1024 	err |= __put_user(&frame->uc, &frame->puc);
1025 	err |= copy_siginfo_to_user(&frame->info, info);
1026 
1027 	/* Create the ucontext.  */
1028 	err |= __put_user(0, &frame->uc.uc_flags);
1029 	err |= __put_user(NULL, &frame->uc.uc_link);
1030 	err |= __put_user((void __user *)current->sas_ss_sp,
1031 			  &frame->uc.uc_stack.ss_sp);
1032 	err |= __put_user(sas_ss_flags(rdusp()),
1033 			  &frame->uc.uc_stack.ss_flags);
1034 	err |= __put_user(current->sas_ss_size, &frame->uc.uc_stack.ss_size);
1035 	err |= rt_setup_ucontext(&frame->uc, regs);
1036 	err |= copy_to_user (&frame->uc.uc_sigmask, set, sizeof(*set));
1037 
1038 	/* Set up to return from userspace.  */
1039 #ifdef CONFIG_MMU
1040 	err |= __put_user(frame->retcode, &frame->pretcode);
1041 #ifdef __mcoldfire__
1042 	/* movel #__NR_rt_sigreturn,d0; trap #0 */
1043 	err |= __put_user(0x203c0000, (long __user *)(frame->retcode + 0));
1044 	err |= __put_user(0x00004e40 + (__NR_rt_sigreturn << 16),
1045 			  (long __user *)(frame->retcode + 4));
1046 #else
1047 	/* moveq #,d0; notb d0; trap #0 */
1048 	err |= __put_user(0x70004600 + ((__NR_rt_sigreturn ^ 0xff) << 16),
1049 			  (long __user *)(frame->retcode + 0));
1050 	err |= __put_user(0x4e40, (short __user *)(frame->retcode + 4));
1051 #endif
1052 #else
1053 	err |= __put_user((void *) ret_from_user_rt_signal, &frame->pretcode);
1054 #endif /* CONFIG_MMU */
1055 
1056 	if (err)
1057 		goto give_sigsegv;
1058 
1059 	push_cache ((unsigned long) &frame->retcode);
1060 
1061 	/*
1062 	 * Set up registers for signal handler.  All the state we are about
1063 	 * to destroy is successfully copied to sigframe.
1064 	 */
1065 	wrusp ((unsigned long) frame);
1066 	regs->pc = (unsigned long) ka->sa.sa_handler;
1067 	adjustformat(regs);
1068 
1069 	/*
1070 	 * This is subtle; if we build more than one sigframe, all but the
1071 	 * first one will see frame format 0 and have fsize == 0, so we won't
1072 	 * screw stkadj.
1073 	 */
1074 	if (fsize)
1075 		regs->stkadj = fsize;
1076 
1077 	/* Prepare to skip over the extra stuff in the exception frame.  */
1078 	if (regs->stkadj) {
1079 		struct pt_regs *tregs =
1080 			(struct pt_regs *)((ulong)regs + regs->stkadj);
1081 #ifdef DEBUG
1082 		printk("Performing stackadjust=%04x\n", regs->stkadj);
1083 #endif
1084 		/* This must be copied with decreasing addresses to
1085                    handle overlaps.  */
1086 		tregs->vector = 0;
1087 		tregs->format = 0;
1088 		tregs->pc = regs->pc;
1089 		tregs->sr = regs->sr;
1090 	}
1091 	return 0;
1092 
1093 give_sigsegv:
1094 	force_sigsegv(sig, current);
1095 	return err;
1096 }
1097 
1098 static inline void
1099 handle_restart(struct pt_regs *regs, struct k_sigaction *ka, int has_handler)
1100 {
1101 	switch (regs->d0) {
1102 	case -ERESTARTNOHAND:
1103 		if (!has_handler)
1104 			goto do_restart;
1105 		regs->d0 = -EINTR;
1106 		break;
1107 
1108 	case -ERESTART_RESTARTBLOCK:
1109 		if (!has_handler) {
1110 			regs->d0 = __NR_restart_syscall;
1111 			regs->pc -= 2;
1112 			break;
1113 		}
1114 		regs->d0 = -EINTR;
1115 		break;
1116 
1117 	case -ERESTARTSYS:
1118 		if (has_handler && !(ka->sa.sa_flags & SA_RESTART)) {
1119 			regs->d0 = -EINTR;
1120 			break;
1121 		}
1122 	/* fallthrough */
1123 	case -ERESTARTNOINTR:
1124 	do_restart:
1125 		regs->d0 = regs->orig_d0;
1126 		regs->pc -= 2;
1127 		break;
1128 	}
1129 }
1130 
1131 /*
1132  * OK, we're invoking a handler
1133  */
1134 static void
1135 handle_signal(int sig, struct k_sigaction *ka, siginfo_t *info,
1136 	      sigset_t *oldset, struct pt_regs *regs)
1137 {
1138 	int err;
1139 	/* are we from a system call? */
1140 	if (regs->orig_d0 >= 0)
1141 		/* If so, check system call restarting.. */
1142 		handle_restart(regs, ka, 1);
1143 
1144 	/* set up the stack frame */
1145 	if (ka->sa.sa_flags & SA_SIGINFO)
1146 		err = setup_rt_frame(sig, ka, info, oldset, regs);
1147 	else
1148 		err = setup_frame(sig, ka, oldset, regs);
1149 
1150 	if (err)
1151 		return;
1152 
1153 	sigorsets(&current->blocked,&current->blocked,&ka->sa.sa_mask);
1154 	if (!(ka->sa.sa_flags & SA_NODEFER))
1155 		sigaddset(&current->blocked,sig);
1156 	recalc_sigpending();
1157 
1158 	if (test_thread_flag(TIF_DELAYED_TRACE)) {
1159 		regs->sr &= ~0x8000;
1160 		send_sig(SIGTRAP, current, 1);
1161 	}
1162 
1163 	clear_thread_flag(TIF_RESTORE_SIGMASK);
1164 }
1165 
1166 /*
1167  * Note that 'init' is a special process: it doesn't get signals it doesn't
1168  * want to handle. Thus you cannot kill init even with a SIGKILL even by
1169  * mistake.
1170  */
1171 asmlinkage void do_signal(struct pt_regs *regs)
1172 {
1173 	siginfo_t info;
1174 	struct k_sigaction ka;
1175 	int signr;
1176 	sigset_t *oldset;
1177 
1178 	current->thread.esp0 = (unsigned long) regs;
1179 
1180 	if (test_thread_flag(TIF_RESTORE_SIGMASK))
1181 		oldset = &current->saved_sigmask;
1182 	else
1183 		oldset = &current->blocked;
1184 
1185 	signr = get_signal_to_deliver(&info, &ka, regs, NULL);
1186 	if (signr > 0) {
1187 		/* Whee!  Actually deliver the signal.  */
1188 		handle_signal(signr, &ka, &info, oldset, regs);
1189 		return;
1190 	}
1191 
1192 	/* Did we come from a system call? */
1193 	if (regs->orig_d0 >= 0)
1194 		/* Restart the system call - no handlers present */
1195 		handle_restart(regs, NULL, 0);
1196 
1197 	/* If there's no signal to deliver, we just restore the saved mask.  */
1198 	if (test_thread_flag(TIF_RESTORE_SIGMASK)) {
1199 		clear_thread_flag(TIF_RESTORE_SIGMASK);
1200 		sigprocmask(SIG_SETMASK, &current->saved_sigmask, NULL);
1201 	}
1202 }
1203