xref: /openbmc/linux/arch/m68k/kernel/signal.c (revision 4f3db074)
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 #include <linux/tracehook.h>
47 
48 #include <asm/setup.h>
49 #include <asm/uaccess.h>
50 #include <asm/pgtable.h>
51 #include <asm/traps.h>
52 #include <asm/ucontext.h>
53 #include <asm/cacheflush.h>
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(void)
113 {
114 	struct pt_regs *regs = signal_pt_regs();
115 	if (regs->orig_d0 < 0)
116 		return;
117 	switch (regs->d0) {
118 	case -ERESTARTNOHAND:
119 	case -ERESTARTSYS:
120 	case -ERESTARTNOINTR:
121 		regs->d0 = regs->orig_d0;
122 		regs->orig_d0 = -1;
123 		regs->pc -= 2;
124 		break;
125 	}
126 }
127 
128 static inline void push_cache (unsigned long vaddr)
129 {
130 	/*
131 	 * Using the old cache_push_v() was really a big waste.
132 	 *
133 	 * What we are trying to do is to flush 8 bytes to ram.
134 	 * Flushing 2 cache lines of 16 bytes is much cheaper than
135 	 * flushing 1 or 2 pages, as previously done in
136 	 * cache_push_v().
137 	 *                                                     Jes
138 	 */
139 	if (CPU_IS_040) {
140 		unsigned long temp;
141 
142 		__asm__ __volatile__ (".chip 68040\n\t"
143 				      "nop\n\t"
144 				      "ptestr (%1)\n\t"
145 				      "movec %%mmusr,%0\n\t"
146 				      ".chip 68k"
147 				      : "=r" (temp)
148 				      : "a" (vaddr));
149 
150 		temp &= PAGE_MASK;
151 		temp |= vaddr & ~PAGE_MASK;
152 
153 		__asm__ __volatile__ (".chip 68040\n\t"
154 				      "nop\n\t"
155 				      "cpushl %%bc,(%0)\n\t"
156 				      ".chip 68k"
157 				      : : "a" (temp));
158 	}
159 	else if (CPU_IS_060) {
160 		unsigned long temp;
161 		__asm__ __volatile__ (".chip 68060\n\t"
162 				      "plpar (%0)\n\t"
163 				      ".chip 68k"
164 				      : "=a" (temp)
165 				      : "0" (vaddr));
166 		__asm__ __volatile__ (".chip 68060\n\t"
167 				      "cpushl %%bc,(%0)\n\t"
168 				      ".chip 68k"
169 				      : : "a" (temp));
170 	} else if (!CPU_IS_COLDFIRE) {
171 		/*
172 		 * 68030/68020 have no writeback cache;
173 		 * still need to clear icache.
174 		 * Note that vaddr is guaranteed to be long word aligned.
175 		 */
176 		unsigned long temp;
177 		asm volatile ("movec %%cacr,%0" : "=r" (temp));
178 		temp += 4;
179 		asm volatile ("movec %0,%%caar\n\t"
180 			      "movec %1,%%cacr"
181 			      : : "r" (vaddr), "r" (temp));
182 		asm volatile ("movec %0,%%caar\n\t"
183 			      "movec %1,%%cacr"
184 			      : : "r" (vaddr + 4), "r" (temp));
185 	} else {
186 		/* CPU_IS_COLDFIRE */
187 #if defined(CONFIG_CACHE_COPYBACK)
188 		flush_cf_dcache(0, DCACHE_MAX_ADDR);
189 #endif
190 		/* Invalidate instruction cache for the pushed bytes */
191 		clear_cf_icache(vaddr, vaddr + 8);
192 	}
193 }
194 
195 static inline void adjustformat(struct pt_regs *regs)
196 {
197 }
198 
199 static inline void save_a5_state(struct sigcontext *sc, struct pt_regs *regs)
200 {
201 }
202 
203 #else /* CONFIG_MMU */
204 
205 void ret_from_user_signal(void);
206 void ret_from_user_rt_signal(void);
207 
208 static inline int frame_extra_sizes(int f)
209 {
210 	/* No frame size adjustments required on non-MMU CPUs */
211 	return 0;
212 }
213 
214 static inline void adjustformat(struct pt_regs *regs)
215 {
216 	((struct switch_stack *)regs - 1)->a5 = current->mm->start_data;
217 	/*
218 	 * set format byte to make stack appear modulo 4, which it will
219 	 * be when doing the rte
220 	 */
221 	regs->format = 0x4;
222 }
223 
224 static inline void save_a5_state(struct sigcontext *sc, struct pt_regs *regs)
225 {
226 	sc->sc_a5 = ((struct switch_stack *)regs - 1)->a5;
227 }
228 
229 static inline void push_cache(unsigned long vaddr)
230 {
231 }
232 
233 #endif /* CONFIG_MMU */
234 
235 /*
236  * Do a signal return; undo the signal stack.
237  *
238  * Keep the return code on the stack quadword aligned!
239  * That makes the cache flush below easier.
240  */
241 
242 struct sigframe
243 {
244 	char __user *pretcode;
245 	int sig;
246 	int code;
247 	struct sigcontext __user *psc;
248 	char retcode[8];
249 	unsigned long extramask[_NSIG_WORDS-1];
250 	struct sigcontext sc;
251 };
252 
253 struct rt_sigframe
254 {
255 	char __user *pretcode;
256 	int sig;
257 	struct siginfo __user *pinfo;
258 	void __user *puc;
259 	char retcode[8];
260 	struct siginfo info;
261 	struct ucontext uc;
262 };
263 
264 #define FPCONTEXT_SIZE	216
265 #define uc_fpstate	uc_filler[0]
266 #define uc_formatvec	uc_filler[FPCONTEXT_SIZE/4]
267 #define uc_extra	uc_filler[FPCONTEXT_SIZE/4+1]
268 
269 #ifdef CONFIG_FPU
270 
271 static unsigned char fpu_version;	/* version number of fpu, set by setup_frame */
272 
273 static inline int restore_fpu_state(struct sigcontext *sc)
274 {
275 	int err = 1;
276 
277 	if (FPU_IS_EMU) {
278 	    /* restore registers */
279 	    memcpy(current->thread.fpcntl, sc->sc_fpcntl, 12);
280 	    memcpy(current->thread.fp, sc->sc_fpregs, 24);
281 	    return 0;
282 	}
283 
284 	if (CPU_IS_060 ? sc->sc_fpstate[2] : sc->sc_fpstate[0]) {
285 	    /* Verify the frame format.  */
286 	    if (!(CPU_IS_060 || CPU_IS_COLDFIRE) &&
287 		 (sc->sc_fpstate[0] != fpu_version))
288 		goto out;
289 	    if (CPU_IS_020_OR_030) {
290 		if (m68k_fputype & FPU_68881 &&
291 		    !(sc->sc_fpstate[1] == 0x18 || sc->sc_fpstate[1] == 0xb4))
292 		    goto out;
293 		if (m68k_fputype & FPU_68882 &&
294 		    !(sc->sc_fpstate[1] == 0x38 || sc->sc_fpstate[1] == 0xd4))
295 		    goto out;
296 	    } else if (CPU_IS_040) {
297 		if (!(sc->sc_fpstate[1] == 0x00 ||
298                       sc->sc_fpstate[1] == 0x28 ||
299                       sc->sc_fpstate[1] == 0x60))
300 		    goto out;
301 	    } else if (CPU_IS_060) {
302 		if (!(sc->sc_fpstate[3] == 0x00 ||
303                       sc->sc_fpstate[3] == 0x60 ||
304 		      sc->sc_fpstate[3] == 0xe0))
305 		    goto out;
306 	    } else if (CPU_IS_COLDFIRE) {
307 		if (!(sc->sc_fpstate[0] == 0x00 ||
308 		      sc->sc_fpstate[0] == 0x05 ||
309 		      sc->sc_fpstate[0] == 0xe5))
310 		    goto out;
311 	    } else
312 		goto out;
313 
314 	    if (CPU_IS_COLDFIRE) {
315 		__asm__ volatile ("fmovemd %0,%%fp0-%%fp1\n\t"
316 				  "fmovel %1,%%fpcr\n\t"
317 				  "fmovel %2,%%fpsr\n\t"
318 				  "fmovel %3,%%fpiar"
319 				  : /* no outputs */
320 				  : "m" (sc->sc_fpregs[0]),
321 				    "m" (sc->sc_fpcntl[0]),
322 				    "m" (sc->sc_fpcntl[1]),
323 				    "m" (sc->sc_fpcntl[2]));
324 	    } else {
325 		__asm__ volatile (".chip 68k/68881\n\t"
326 				  "fmovemx %0,%%fp0-%%fp1\n\t"
327 				  "fmoveml %1,%%fpcr/%%fpsr/%%fpiar\n\t"
328 				  ".chip 68k"
329 				  : /* no outputs */
330 				  : "m" (*sc->sc_fpregs),
331 				    "m" (*sc->sc_fpcntl));
332 	    }
333 	}
334 
335 	if (CPU_IS_COLDFIRE) {
336 		__asm__ volatile ("frestore %0" : : "m" (*sc->sc_fpstate));
337 	} else {
338 		__asm__ volatile (".chip 68k/68881\n\t"
339 				  "frestore %0\n\t"
340 				  ".chip 68k"
341 				  : : "m" (*sc->sc_fpstate));
342 	}
343 	err = 0;
344 
345 out:
346 	return err;
347 }
348 
349 static inline int rt_restore_fpu_state(struct ucontext __user *uc)
350 {
351 	unsigned char fpstate[FPCONTEXT_SIZE];
352 	int context_size = CPU_IS_060 ? 8 : (CPU_IS_COLDFIRE ? 12 : 0);
353 	fpregset_t fpregs;
354 	int err = 1;
355 
356 	if (FPU_IS_EMU) {
357 		/* restore fpu control register */
358 		if (__copy_from_user(current->thread.fpcntl,
359 				uc->uc_mcontext.fpregs.f_fpcntl, 12))
360 			goto out;
361 		/* restore all other fpu register */
362 		if (__copy_from_user(current->thread.fp,
363 				uc->uc_mcontext.fpregs.f_fpregs, 96))
364 			goto out;
365 		return 0;
366 	}
367 
368 	if (__get_user(*(long *)fpstate, (long __user *)&uc->uc_fpstate))
369 		goto out;
370 	if (CPU_IS_060 ? fpstate[2] : fpstate[0]) {
371 		if (!(CPU_IS_060 || CPU_IS_COLDFIRE))
372 			context_size = fpstate[1];
373 		/* Verify the frame format.  */
374 		if (!(CPU_IS_060 || CPU_IS_COLDFIRE) &&
375 		     (fpstate[0] != fpu_version))
376 			goto out;
377 		if (CPU_IS_020_OR_030) {
378 			if (m68k_fputype & FPU_68881 &&
379 			    !(context_size == 0x18 || context_size == 0xb4))
380 				goto out;
381 			if (m68k_fputype & FPU_68882 &&
382 			    !(context_size == 0x38 || context_size == 0xd4))
383 				goto out;
384 		} else if (CPU_IS_040) {
385 			if (!(context_size == 0x00 ||
386 			      context_size == 0x28 ||
387 			      context_size == 0x60))
388 				goto out;
389 		} else if (CPU_IS_060) {
390 			if (!(fpstate[3] == 0x00 ||
391 			      fpstate[3] == 0x60 ||
392 			      fpstate[3] == 0xe0))
393 				goto out;
394 		} else if (CPU_IS_COLDFIRE) {
395 			if (!(fpstate[3] == 0x00 ||
396 			      fpstate[3] == 0x05 ||
397 			      fpstate[3] == 0xe5))
398 				goto out;
399 		} else
400 			goto out;
401 		if (__copy_from_user(&fpregs, &uc->uc_mcontext.fpregs,
402 				     sizeof(fpregs)))
403 			goto out;
404 
405 		if (CPU_IS_COLDFIRE) {
406 			__asm__ volatile ("fmovemd %0,%%fp0-%%fp7\n\t"
407 					  "fmovel %1,%%fpcr\n\t"
408 					  "fmovel %2,%%fpsr\n\t"
409 					  "fmovel %3,%%fpiar"
410 					  : /* no outputs */
411 					  : "m" (fpregs.f_fpregs[0]),
412 					    "m" (fpregs.f_fpcntl[0]),
413 					    "m" (fpregs.f_fpcntl[1]),
414 					    "m" (fpregs.f_fpcntl[2]));
415 		} else {
416 			__asm__ volatile (".chip 68k/68881\n\t"
417 					  "fmovemx %0,%%fp0-%%fp7\n\t"
418 					  "fmoveml %1,%%fpcr/%%fpsr/%%fpiar\n\t"
419 					  ".chip 68k"
420 					  : /* no outputs */
421 					  : "m" (*fpregs.f_fpregs),
422 					    "m" (*fpregs.f_fpcntl));
423 		}
424 	}
425 	if (context_size &&
426 	    __copy_from_user(fpstate + 4, (long __user *)&uc->uc_fpstate + 1,
427 			     context_size))
428 		goto out;
429 
430 	if (CPU_IS_COLDFIRE) {
431 		__asm__ volatile ("frestore %0" : : "m" (*fpstate));
432 	} else {
433 		__asm__ volatile (".chip 68k/68881\n\t"
434 				  "frestore %0\n\t"
435 				  ".chip 68k"
436 				  : : "m" (*fpstate));
437 	}
438 	err = 0;
439 
440 out:
441 	return err;
442 }
443 
444 /*
445  * Set up a signal frame.
446  */
447 static inline void save_fpu_state(struct sigcontext *sc, struct pt_regs *regs)
448 {
449 	if (FPU_IS_EMU) {
450 		/* save registers */
451 		memcpy(sc->sc_fpcntl, current->thread.fpcntl, 12);
452 		memcpy(sc->sc_fpregs, current->thread.fp, 24);
453 		return;
454 	}
455 
456 	if (CPU_IS_COLDFIRE) {
457 		__asm__ volatile ("fsave %0"
458 				  : : "m" (*sc->sc_fpstate) : "memory");
459 	} else {
460 		__asm__ volatile (".chip 68k/68881\n\t"
461 				  "fsave %0\n\t"
462 				  ".chip 68k"
463 				  : : "m" (*sc->sc_fpstate) : "memory");
464 	}
465 
466 	if (CPU_IS_060 ? sc->sc_fpstate[2] : sc->sc_fpstate[0]) {
467 		fpu_version = sc->sc_fpstate[0];
468 		if (CPU_IS_020_OR_030 &&
469 		    regs->vector >= (VEC_FPBRUC * 4) &&
470 		    regs->vector <= (VEC_FPNAN * 4)) {
471 			/* Clear pending exception in 68882 idle frame */
472 			if (*(unsigned short *) sc->sc_fpstate == 0x1f38)
473 				sc->sc_fpstate[0x38] |= 1 << 3;
474 		}
475 
476 		if (CPU_IS_COLDFIRE) {
477 			__asm__ volatile ("fmovemd %%fp0-%%fp1,%0\n\t"
478 					  "fmovel %%fpcr,%1\n\t"
479 					  "fmovel %%fpsr,%2\n\t"
480 					  "fmovel %%fpiar,%3"
481 					  : "=m" (sc->sc_fpregs[0]),
482 					    "=m" (sc->sc_fpcntl[0]),
483 					    "=m" (sc->sc_fpcntl[1]),
484 					    "=m" (sc->sc_fpcntl[2])
485 					  : /* no inputs */
486 					  : "memory");
487 		} else {
488 			__asm__ volatile (".chip 68k/68881\n\t"
489 					  "fmovemx %%fp0-%%fp1,%0\n\t"
490 					  "fmoveml %%fpcr/%%fpsr/%%fpiar,%1\n\t"
491 					  ".chip 68k"
492 					  : "=m" (*sc->sc_fpregs),
493 					    "=m" (*sc->sc_fpcntl)
494 					  : /* no inputs */
495 					  : "memory");
496 		}
497 	}
498 }
499 
500 static inline int rt_save_fpu_state(struct ucontext __user *uc, struct pt_regs *regs)
501 {
502 	unsigned char fpstate[FPCONTEXT_SIZE];
503 	int context_size = CPU_IS_060 ? 8 : (CPU_IS_COLDFIRE ? 12 : 0);
504 	int err = 0;
505 
506 	if (FPU_IS_EMU) {
507 		/* save fpu control register */
508 		err |= copy_to_user(uc->uc_mcontext.fpregs.f_fpcntl,
509 				current->thread.fpcntl, 12);
510 		/* save all other fpu register */
511 		err |= copy_to_user(uc->uc_mcontext.fpregs.f_fpregs,
512 				current->thread.fp, 96);
513 		return err;
514 	}
515 
516 	if (CPU_IS_COLDFIRE) {
517 		__asm__ volatile ("fsave %0" : : "m" (*fpstate) : "memory");
518 	} else {
519 		__asm__ volatile (".chip 68k/68881\n\t"
520 				  "fsave %0\n\t"
521 				  ".chip 68k"
522 				  : : "m" (*fpstate) : "memory");
523 	}
524 
525 	err |= __put_user(*(long *)fpstate, (long __user *)&uc->uc_fpstate);
526 	if (CPU_IS_060 ? fpstate[2] : fpstate[0]) {
527 		fpregset_t fpregs;
528 		if (!(CPU_IS_060 || CPU_IS_COLDFIRE))
529 			context_size = fpstate[1];
530 		fpu_version = fpstate[0];
531 		if (CPU_IS_020_OR_030 &&
532 		    regs->vector >= (VEC_FPBRUC * 4) &&
533 		    regs->vector <= (VEC_FPNAN * 4)) {
534 			/* Clear pending exception in 68882 idle frame */
535 			if (*(unsigned short *) fpstate == 0x1f38)
536 				fpstate[0x38] |= 1 << 3;
537 		}
538 		if (CPU_IS_COLDFIRE) {
539 			__asm__ volatile ("fmovemd %%fp0-%%fp7,%0\n\t"
540 					  "fmovel %%fpcr,%1\n\t"
541 					  "fmovel %%fpsr,%2\n\t"
542 					  "fmovel %%fpiar,%3"
543 					  : "=m" (fpregs.f_fpregs[0]),
544 					    "=m" (fpregs.f_fpcntl[0]),
545 					    "=m" (fpregs.f_fpcntl[1]),
546 					    "=m" (fpregs.f_fpcntl[2])
547 					  : /* no inputs */
548 					  : "memory");
549 		} else {
550 			__asm__ volatile (".chip 68k/68881\n\t"
551 					  "fmovemx %%fp0-%%fp7,%0\n\t"
552 					  "fmoveml %%fpcr/%%fpsr/%%fpiar,%1\n\t"
553 					  ".chip 68k"
554 					  : "=m" (*fpregs.f_fpregs),
555 					    "=m" (*fpregs.f_fpcntl)
556 					  : /* no inputs */
557 					  : "memory");
558 		}
559 		err |= copy_to_user(&uc->uc_mcontext.fpregs, &fpregs,
560 				    sizeof(fpregs));
561 	}
562 	if (context_size)
563 		err |= copy_to_user((long __user *)&uc->uc_fpstate + 1, fpstate + 4,
564 				    context_size);
565 	return err;
566 }
567 
568 #else /* CONFIG_FPU */
569 
570 /*
571  * For the case with no FPU configured these all do nothing.
572  */
573 static inline int restore_fpu_state(struct sigcontext *sc)
574 {
575 	return 0;
576 }
577 
578 static inline int rt_restore_fpu_state(struct ucontext __user *uc)
579 {
580 	return 0;
581 }
582 
583 static inline void save_fpu_state(struct sigcontext *sc, struct pt_regs *regs)
584 {
585 }
586 
587 static inline int rt_save_fpu_state(struct ucontext __user *uc, struct pt_regs *regs)
588 {
589 	return 0;
590 }
591 
592 #endif /* CONFIG_FPU */
593 
594 static int mangle_kernel_stack(struct pt_regs *regs, int formatvec,
595 			       void __user *fp)
596 {
597 	int fsize = frame_extra_sizes(formatvec >> 12);
598 	if (fsize < 0) {
599 		/*
600 		 * user process trying to return with weird frame format
601 		 */
602 #ifdef DEBUG
603 		printk("user process returning with weird frame format\n");
604 #endif
605 		return 1;
606 	}
607 	if (!fsize) {
608 		regs->format = formatvec >> 12;
609 		regs->vector = formatvec & 0xfff;
610 	} else {
611 		struct switch_stack *sw = (struct switch_stack *)regs - 1;
612 		unsigned long buf[fsize / 2]; /* yes, twice as much */
613 
614 		/* that'll make sure that expansion won't crap over data */
615 		if (copy_from_user(buf + fsize / 4, fp, fsize))
616 			return 1;
617 
618 		/* point of no return */
619 		regs->format = formatvec >> 12;
620 		regs->vector = formatvec & 0xfff;
621 #define frame_offset (sizeof(struct pt_regs)+sizeof(struct switch_stack))
622 		__asm__ __volatile__ (
623 #ifdef CONFIG_COLDFIRE
624 			 "   movel %0,%/sp\n\t"
625 			 "   bra ret_from_signal\n"
626 #else
627 			 "   movel %0,%/a0\n\t"
628 			 "   subl %1,%/a0\n\t"     /* make room on stack */
629 			 "   movel %/a0,%/sp\n\t"  /* set stack pointer */
630 			 /* move switch_stack and pt_regs */
631 			 "1: movel %0@+,%/a0@+\n\t"
632 			 "   dbra %2,1b\n\t"
633 			 "   lea %/sp@(%c3),%/a0\n\t" /* add offset of fmt */
634 			 "   lsrl  #2,%1\n\t"
635 			 "   subql #1,%1\n\t"
636 			 /* copy to the gap we'd made */
637 			 "2: movel %4@+,%/a0@+\n\t"
638 			 "   dbra %1,2b\n\t"
639 			 "   bral ret_from_signal\n"
640 #endif
641 			 : /* no outputs, it doesn't ever return */
642 			 : "a" (sw), "d" (fsize), "d" (frame_offset/4-1),
643 			   "n" (frame_offset), "a" (buf + fsize/4)
644 			 : "a0");
645 #undef frame_offset
646 	}
647 	return 0;
648 }
649 
650 static inline int
651 restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *usc, void __user *fp)
652 {
653 	int formatvec;
654 	struct sigcontext context;
655 	int err = 0;
656 
657 	/* Always make any pending restarted system calls return -EINTR */
658 	current->restart_block.fn = do_no_restart_syscall;
659 
660 	/* get previous context */
661 	if (copy_from_user(&context, usc, sizeof(context)))
662 		goto badframe;
663 
664 	/* restore passed registers */
665 	regs->d0 = context.sc_d0;
666 	regs->d1 = context.sc_d1;
667 	regs->a0 = context.sc_a0;
668 	regs->a1 = context.sc_a1;
669 	regs->sr = (regs->sr & 0xff00) | (context.sc_sr & 0xff);
670 	regs->pc = context.sc_pc;
671 	regs->orig_d0 = -1;		/* disable syscall checks */
672 	wrusp(context.sc_usp);
673 	formatvec = context.sc_formatvec;
674 
675 	err = restore_fpu_state(&context);
676 
677 	if (err || mangle_kernel_stack(regs, formatvec, fp))
678 		goto badframe;
679 
680 	return 0;
681 
682 badframe:
683 	return 1;
684 }
685 
686 static inline int
687 rt_restore_ucontext(struct pt_regs *regs, struct switch_stack *sw,
688 		    struct ucontext __user *uc)
689 {
690 	int temp;
691 	greg_t __user *gregs = uc->uc_mcontext.gregs;
692 	unsigned long usp;
693 	int err;
694 
695 	/* Always make any pending restarted system calls return -EINTR */
696 	current->restart_block.fn = do_no_restart_syscall;
697 
698 	err = __get_user(temp, &uc->uc_mcontext.version);
699 	if (temp != MCONTEXT_VERSION)
700 		goto badframe;
701 	/* restore passed registers */
702 	err |= __get_user(regs->d0, &gregs[0]);
703 	err |= __get_user(regs->d1, &gregs[1]);
704 	err |= __get_user(regs->d2, &gregs[2]);
705 	err |= __get_user(regs->d3, &gregs[3]);
706 	err |= __get_user(regs->d4, &gregs[4]);
707 	err |= __get_user(regs->d5, &gregs[5]);
708 	err |= __get_user(sw->d6, &gregs[6]);
709 	err |= __get_user(sw->d7, &gregs[7]);
710 	err |= __get_user(regs->a0, &gregs[8]);
711 	err |= __get_user(regs->a1, &gregs[9]);
712 	err |= __get_user(regs->a2, &gregs[10]);
713 	err |= __get_user(sw->a3, &gregs[11]);
714 	err |= __get_user(sw->a4, &gregs[12]);
715 	err |= __get_user(sw->a5, &gregs[13]);
716 	err |= __get_user(sw->a6, &gregs[14]);
717 	err |= __get_user(usp, &gregs[15]);
718 	wrusp(usp);
719 	err |= __get_user(regs->pc, &gregs[16]);
720 	err |= __get_user(temp, &gregs[17]);
721 	regs->sr = (regs->sr & 0xff00) | (temp & 0xff);
722 	regs->orig_d0 = -1;		/* disable syscall checks */
723 	err |= __get_user(temp, &uc->uc_formatvec);
724 
725 	err |= rt_restore_fpu_state(uc);
726 	err |= restore_altstack(&uc->uc_stack);
727 
728 	if (err)
729 		goto badframe;
730 
731 	if (mangle_kernel_stack(regs, temp, &uc->uc_extra))
732 		goto badframe;
733 
734 	return 0;
735 
736 badframe:
737 	return 1;
738 }
739 
740 asmlinkage int do_sigreturn(unsigned long __unused)
741 {
742 	struct switch_stack *sw = (struct switch_stack *) &__unused;
743 	struct pt_regs *regs = (struct pt_regs *) (sw + 1);
744 	unsigned long usp = rdusp();
745 	struct sigframe __user *frame = (struct sigframe __user *)(usp - 4);
746 	sigset_t set;
747 
748 	if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
749 		goto badframe;
750 	if (__get_user(set.sig[0], &frame->sc.sc_mask) ||
751 	    (_NSIG_WORDS > 1 &&
752 	     __copy_from_user(&set.sig[1], &frame->extramask,
753 			      sizeof(frame->extramask))))
754 		goto badframe;
755 
756 	set_current_blocked(&set);
757 
758 	if (restore_sigcontext(regs, &frame->sc, frame + 1))
759 		goto badframe;
760 	return regs->d0;
761 
762 badframe:
763 	force_sig(SIGSEGV, current);
764 	return 0;
765 }
766 
767 asmlinkage int do_rt_sigreturn(unsigned long __unused)
768 {
769 	struct switch_stack *sw = (struct switch_stack *) &__unused;
770 	struct pt_regs *regs = (struct pt_regs *) (sw + 1);
771 	unsigned long usp = rdusp();
772 	struct rt_sigframe __user *frame = (struct rt_sigframe __user *)(usp - 4);
773 	sigset_t set;
774 
775 	if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
776 		goto badframe;
777 	if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set)))
778 		goto badframe;
779 
780 	set_current_blocked(&set);
781 
782 	if (rt_restore_ucontext(regs, sw, &frame->uc))
783 		goto badframe;
784 	return regs->d0;
785 
786 badframe:
787 	force_sig(SIGSEGV, current);
788 	return 0;
789 }
790 
791 static void setup_sigcontext(struct sigcontext *sc, struct pt_regs *regs,
792 			     unsigned long mask)
793 {
794 	sc->sc_mask = mask;
795 	sc->sc_usp = rdusp();
796 	sc->sc_d0 = regs->d0;
797 	sc->sc_d1 = regs->d1;
798 	sc->sc_a0 = regs->a0;
799 	sc->sc_a1 = regs->a1;
800 	sc->sc_sr = regs->sr;
801 	sc->sc_pc = regs->pc;
802 	sc->sc_formatvec = regs->format << 12 | regs->vector;
803 	save_a5_state(sc, regs);
804 	save_fpu_state(sc, regs);
805 }
806 
807 static inline int rt_setup_ucontext(struct ucontext __user *uc, struct pt_regs *regs)
808 {
809 	struct switch_stack *sw = (struct switch_stack *)regs - 1;
810 	greg_t __user *gregs = uc->uc_mcontext.gregs;
811 	int err = 0;
812 
813 	err |= __put_user(MCONTEXT_VERSION, &uc->uc_mcontext.version);
814 	err |= __put_user(regs->d0, &gregs[0]);
815 	err |= __put_user(regs->d1, &gregs[1]);
816 	err |= __put_user(regs->d2, &gregs[2]);
817 	err |= __put_user(regs->d3, &gregs[3]);
818 	err |= __put_user(regs->d4, &gregs[4]);
819 	err |= __put_user(regs->d5, &gregs[5]);
820 	err |= __put_user(sw->d6, &gregs[6]);
821 	err |= __put_user(sw->d7, &gregs[7]);
822 	err |= __put_user(regs->a0, &gregs[8]);
823 	err |= __put_user(regs->a1, &gregs[9]);
824 	err |= __put_user(regs->a2, &gregs[10]);
825 	err |= __put_user(sw->a3, &gregs[11]);
826 	err |= __put_user(sw->a4, &gregs[12]);
827 	err |= __put_user(sw->a5, &gregs[13]);
828 	err |= __put_user(sw->a6, &gregs[14]);
829 	err |= __put_user(rdusp(), &gregs[15]);
830 	err |= __put_user(regs->pc, &gregs[16]);
831 	err |= __put_user(regs->sr, &gregs[17]);
832 	err |= __put_user((regs->format << 12) | regs->vector, &uc->uc_formatvec);
833 	err |= rt_save_fpu_state(uc, regs);
834 	return err;
835 }
836 
837 static inline void __user *
838 get_sigframe(struct ksignal *ksig, size_t frame_size)
839 {
840 	unsigned long usp = sigsp(rdusp(), ksig);
841 
842 	return (void __user *)((usp - frame_size) & -8UL);
843 }
844 
845 static int setup_frame(struct ksignal *ksig, sigset_t *set,
846 			struct pt_regs *regs)
847 {
848 	struct sigframe __user *frame;
849 	int fsize = frame_extra_sizes(regs->format);
850 	struct sigcontext context;
851 	int err = 0, sig = ksig->sig;
852 
853 	if (fsize < 0) {
854 #ifdef DEBUG
855 		printk ("setup_frame: Unknown frame format %#x\n",
856 			regs->format);
857 #endif
858 		return -EFAULT;
859 	}
860 
861 	frame = get_sigframe(ksig, sizeof(*frame) + fsize);
862 
863 	if (fsize)
864 		err |= copy_to_user (frame + 1, regs + 1, fsize);
865 
866 	err |= __put_user(sig, &frame->sig);
867 
868 	err |= __put_user(regs->vector, &frame->code);
869 	err |= __put_user(&frame->sc, &frame->psc);
870 
871 	if (_NSIG_WORDS > 1)
872 		err |= copy_to_user(frame->extramask, &set->sig[1],
873 				    sizeof(frame->extramask));
874 
875 	setup_sigcontext(&context, regs, set->sig[0]);
876 	err |= copy_to_user (&frame->sc, &context, sizeof(context));
877 
878 	/* Set up to return from userspace.  */
879 #ifdef CONFIG_MMU
880 	err |= __put_user(frame->retcode, &frame->pretcode);
881 	/* moveq #,d0; trap #0 */
882 	err |= __put_user(0x70004e40 + (__NR_sigreturn << 16),
883 			  (long __user *)(frame->retcode));
884 #else
885 	err |= __put_user((void *) ret_from_user_signal, &frame->pretcode);
886 #endif
887 
888 	if (err)
889 		return -EFAULT;
890 
891 	push_cache ((unsigned long) &frame->retcode);
892 
893 	/*
894 	 * Set up registers for signal handler.  All the state we are about
895 	 * to destroy is successfully copied to sigframe.
896 	 */
897 	wrusp ((unsigned long) frame);
898 	regs->pc = (unsigned long) ksig->ka.sa.sa_handler;
899 	adjustformat(regs);
900 
901 	/*
902 	 * This is subtle; if we build more than one sigframe, all but the
903 	 * first one will see frame format 0 and have fsize == 0, so we won't
904 	 * screw stkadj.
905 	 */
906 	if (fsize)
907 		regs->stkadj = fsize;
908 
909 	/* Prepare to skip over the extra stuff in the exception frame.  */
910 	if (regs->stkadj) {
911 		struct pt_regs *tregs =
912 			(struct pt_regs *)((ulong)regs + regs->stkadj);
913 #ifdef DEBUG
914 		printk("Performing stackadjust=%04x\n", regs->stkadj);
915 #endif
916 		/* This must be copied with decreasing addresses to
917                    handle overlaps.  */
918 		tregs->vector = 0;
919 		tregs->format = 0;
920 		tregs->pc = regs->pc;
921 		tregs->sr = regs->sr;
922 	}
923 	return 0;
924 }
925 
926 static int setup_rt_frame(struct ksignal *ksig, sigset_t *set,
927 			   struct pt_regs *regs)
928 {
929 	struct rt_sigframe __user *frame;
930 	int fsize = frame_extra_sizes(regs->format);
931 	int err = 0, sig = ksig->sig;
932 
933 	if (fsize < 0) {
934 #ifdef DEBUG
935 		printk ("setup_frame: Unknown frame format %#x\n",
936 			regs->format);
937 #endif
938 		return -EFAULT;
939 	}
940 
941 	frame = get_sigframe(ksig, sizeof(*frame));
942 
943 	if (fsize)
944 		err |= copy_to_user (&frame->uc.uc_extra, regs + 1, fsize);
945 
946 	err |= __put_user(sig, &frame->sig);
947 	err |= __put_user(&frame->info, &frame->pinfo);
948 	err |= __put_user(&frame->uc, &frame->puc);
949 	err |= copy_siginfo_to_user(&frame->info, &ksig->info);
950 
951 	/* Create the ucontext.  */
952 	err |= __put_user(0, &frame->uc.uc_flags);
953 	err |= __put_user(NULL, &frame->uc.uc_link);
954 	err |= __save_altstack(&frame->uc.uc_stack, rdusp());
955 	err |= rt_setup_ucontext(&frame->uc, regs);
956 	err |= copy_to_user (&frame->uc.uc_sigmask, set, sizeof(*set));
957 
958 	/* Set up to return from userspace.  */
959 #ifdef CONFIG_MMU
960 	err |= __put_user(frame->retcode, &frame->pretcode);
961 #ifdef __mcoldfire__
962 	/* movel #__NR_rt_sigreturn,d0; trap #0 */
963 	err |= __put_user(0x203c0000, (long __user *)(frame->retcode + 0));
964 	err |= __put_user(0x00004e40 + (__NR_rt_sigreturn << 16),
965 			  (long __user *)(frame->retcode + 4));
966 #else
967 	/* moveq #,d0; notb d0; trap #0 */
968 	err |= __put_user(0x70004600 + ((__NR_rt_sigreturn ^ 0xff) << 16),
969 			  (long __user *)(frame->retcode + 0));
970 	err |= __put_user(0x4e40, (short __user *)(frame->retcode + 4));
971 #endif
972 #else
973 	err |= __put_user((void *) ret_from_user_rt_signal, &frame->pretcode);
974 #endif /* CONFIG_MMU */
975 
976 	if (err)
977 		return -EFAULT;
978 
979 	push_cache ((unsigned long) &frame->retcode);
980 
981 	/*
982 	 * Set up registers for signal handler.  All the state we are about
983 	 * to destroy is successfully copied to sigframe.
984 	 */
985 	wrusp ((unsigned long) frame);
986 	regs->pc = (unsigned long) ksig->ka.sa.sa_handler;
987 	adjustformat(regs);
988 
989 	/*
990 	 * This is subtle; if we build more than one sigframe, all but the
991 	 * first one will see frame format 0 and have fsize == 0, so we won't
992 	 * screw stkadj.
993 	 */
994 	if (fsize)
995 		regs->stkadj = fsize;
996 
997 	/* Prepare to skip over the extra stuff in the exception frame.  */
998 	if (regs->stkadj) {
999 		struct pt_regs *tregs =
1000 			(struct pt_regs *)((ulong)regs + regs->stkadj);
1001 #ifdef DEBUG
1002 		printk("Performing stackadjust=%04x\n", regs->stkadj);
1003 #endif
1004 		/* This must be copied with decreasing addresses to
1005                    handle overlaps.  */
1006 		tregs->vector = 0;
1007 		tregs->format = 0;
1008 		tregs->pc = regs->pc;
1009 		tregs->sr = regs->sr;
1010 	}
1011 	return 0;
1012 }
1013 
1014 static inline void
1015 handle_restart(struct pt_regs *regs, struct k_sigaction *ka, int has_handler)
1016 {
1017 	switch (regs->d0) {
1018 	case -ERESTARTNOHAND:
1019 		if (!has_handler)
1020 			goto do_restart;
1021 		regs->d0 = -EINTR;
1022 		break;
1023 
1024 	case -ERESTART_RESTARTBLOCK:
1025 		if (!has_handler) {
1026 			regs->d0 = __NR_restart_syscall;
1027 			regs->pc -= 2;
1028 			break;
1029 		}
1030 		regs->d0 = -EINTR;
1031 		break;
1032 
1033 	case -ERESTARTSYS:
1034 		if (has_handler && !(ka->sa.sa_flags & SA_RESTART)) {
1035 			regs->d0 = -EINTR;
1036 			break;
1037 		}
1038 	/* fallthrough */
1039 	case -ERESTARTNOINTR:
1040 	do_restart:
1041 		regs->d0 = regs->orig_d0;
1042 		regs->pc -= 2;
1043 		break;
1044 	}
1045 }
1046 
1047 /*
1048  * OK, we're invoking a handler
1049  */
1050 static void
1051 handle_signal(struct ksignal *ksig, struct pt_regs *regs)
1052 {
1053 	sigset_t *oldset = sigmask_to_save();
1054 	int err;
1055 	/* are we from a system call? */
1056 	if (regs->orig_d0 >= 0)
1057 		/* If so, check system call restarting.. */
1058 		handle_restart(regs, &ksig->ka, 1);
1059 
1060 	/* set up the stack frame */
1061 	if (ksig->ka.sa.sa_flags & SA_SIGINFO)
1062 		err = setup_rt_frame(ksig, oldset, regs);
1063 	else
1064 		err = setup_frame(ksig, oldset, regs);
1065 
1066 	signal_setup_done(err, ksig, 0);
1067 
1068 	if (test_thread_flag(TIF_DELAYED_TRACE)) {
1069 		regs->sr &= ~0x8000;
1070 		send_sig(SIGTRAP, current, 1);
1071 	}
1072 }
1073 
1074 /*
1075  * Note that 'init' is a special process: it doesn't get signals it doesn't
1076  * want to handle. Thus you cannot kill init even with a SIGKILL even by
1077  * mistake.
1078  */
1079 static void do_signal(struct pt_regs *regs)
1080 {
1081 	struct ksignal ksig;
1082 
1083 	current->thread.esp0 = (unsigned long) regs;
1084 
1085 	if (get_signal(&ksig)) {
1086 		/* Whee!  Actually deliver the signal.  */
1087 		handle_signal(&ksig, regs);
1088 		return;
1089 	}
1090 
1091 	/* Did we come from a system call? */
1092 	if (regs->orig_d0 >= 0)
1093 		/* Restart the system call - no handlers present */
1094 		handle_restart(regs, NULL, 0);
1095 
1096 	/* If there's no signal to deliver, we just restore the saved mask.  */
1097 	restore_saved_sigmask();
1098 }
1099 
1100 void do_notify_resume(struct pt_regs *regs)
1101 {
1102 	if (test_thread_flag(TIF_SIGPENDING))
1103 		do_signal(regs);
1104 
1105 	if (test_and_clear_thread_flag(TIF_NOTIFY_RESUME))
1106 		tracehook_notify_resume(regs);
1107 }
1108