xref: /openbmc/linux/arch/m68k/kernel/signal.c (revision e0f6d1a5)
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/extable.h>
46 #include <linux/tracehook.h>
47 
48 #include <asm/setup.h>
49 #include <linux/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 fixup_exception(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 static inline void push_cache (unsigned long vaddr)
113 {
114 	/*
115 	 * Using the old cache_push_v() was really a big waste.
116 	 *
117 	 * What we are trying to do is to flush 8 bytes to ram.
118 	 * Flushing 2 cache lines of 16 bytes is much cheaper than
119 	 * flushing 1 or 2 pages, as previously done in
120 	 * cache_push_v().
121 	 *                                                     Jes
122 	 */
123 	if (CPU_IS_040) {
124 		unsigned long temp;
125 
126 		__asm__ __volatile__ (".chip 68040\n\t"
127 				      "nop\n\t"
128 				      "ptestr (%1)\n\t"
129 				      "movec %%mmusr,%0\n\t"
130 				      ".chip 68k"
131 				      : "=r" (temp)
132 				      : "a" (vaddr));
133 
134 		temp &= PAGE_MASK;
135 		temp |= vaddr & ~PAGE_MASK;
136 
137 		__asm__ __volatile__ (".chip 68040\n\t"
138 				      "nop\n\t"
139 				      "cpushl %%bc,(%0)\n\t"
140 				      ".chip 68k"
141 				      : : "a" (temp));
142 	}
143 	else if (CPU_IS_060) {
144 		unsigned long temp;
145 		__asm__ __volatile__ (".chip 68060\n\t"
146 				      "plpar (%0)\n\t"
147 				      ".chip 68k"
148 				      : "=a" (temp)
149 				      : "0" (vaddr));
150 		__asm__ __volatile__ (".chip 68060\n\t"
151 				      "cpushl %%bc,(%0)\n\t"
152 				      ".chip 68k"
153 				      : : "a" (temp));
154 	} else if (!CPU_IS_COLDFIRE) {
155 		/*
156 		 * 68030/68020 have no writeback cache;
157 		 * still need to clear icache.
158 		 * Note that vaddr is guaranteed to be long word aligned.
159 		 */
160 		unsigned long temp;
161 		asm volatile ("movec %%cacr,%0" : "=r" (temp));
162 		temp += 4;
163 		asm volatile ("movec %0,%%caar\n\t"
164 			      "movec %1,%%cacr"
165 			      : : "r" (vaddr), "r" (temp));
166 		asm volatile ("movec %0,%%caar\n\t"
167 			      "movec %1,%%cacr"
168 			      : : "r" (vaddr + 4), "r" (temp));
169 	} else {
170 		/* CPU_IS_COLDFIRE */
171 #if defined(CONFIG_CACHE_COPYBACK)
172 		flush_cf_dcache(0, DCACHE_MAX_ADDR);
173 #endif
174 		/* Invalidate instruction cache for the pushed bytes */
175 		clear_cf_icache(vaddr, vaddr + 8);
176 	}
177 }
178 
179 static inline void adjustformat(struct pt_regs *regs)
180 {
181 }
182 
183 static inline void save_a5_state(struct sigcontext *sc, struct pt_regs *regs)
184 {
185 }
186 
187 #else /* CONFIG_MMU */
188 
189 void ret_from_user_signal(void);
190 void ret_from_user_rt_signal(void);
191 
192 static inline int frame_extra_sizes(int f)
193 {
194 	/* No frame size adjustments required on non-MMU CPUs */
195 	return 0;
196 }
197 
198 static inline void adjustformat(struct pt_regs *regs)
199 {
200 	/*
201 	 * set format byte to make stack appear modulo 4, which it will
202 	 * be when doing the rte
203 	 */
204 	regs->format = 0x4;
205 }
206 
207 static inline void save_a5_state(struct sigcontext *sc, struct pt_regs *regs)
208 {
209 	sc->sc_a5 = ((struct switch_stack *)regs - 1)->a5;
210 }
211 
212 static inline void push_cache(unsigned long vaddr)
213 {
214 }
215 
216 #endif /* CONFIG_MMU */
217 
218 /*
219  * Do a signal return; undo the signal stack.
220  *
221  * Keep the return code on the stack quadword aligned!
222  * That makes the cache flush below easier.
223  */
224 
225 struct sigframe
226 {
227 	char __user *pretcode;
228 	int sig;
229 	int code;
230 	struct sigcontext __user *psc;
231 	char retcode[8];
232 	unsigned long extramask[_NSIG_WORDS-1];
233 	struct sigcontext sc;
234 };
235 
236 struct rt_sigframe
237 {
238 	char __user *pretcode;
239 	int sig;
240 	struct siginfo __user *pinfo;
241 	void __user *puc;
242 	char retcode[8];
243 	struct siginfo info;
244 	struct ucontext uc;
245 };
246 
247 #define FPCONTEXT_SIZE	216
248 #define uc_fpstate	uc_filler[0]
249 #define uc_formatvec	uc_filler[FPCONTEXT_SIZE/4]
250 #define uc_extra	uc_filler[FPCONTEXT_SIZE/4+1]
251 
252 #ifdef CONFIG_FPU
253 
254 static unsigned char fpu_version;	/* version number of fpu, set by setup_frame */
255 
256 static inline int restore_fpu_state(struct sigcontext *sc)
257 {
258 	int err = 1;
259 
260 	if (FPU_IS_EMU) {
261 	    /* restore registers */
262 	    memcpy(current->thread.fpcntl, sc->sc_fpcntl, 12);
263 	    memcpy(current->thread.fp, sc->sc_fpregs, 24);
264 	    return 0;
265 	}
266 
267 	if (CPU_IS_060 ? sc->sc_fpstate[2] : sc->sc_fpstate[0]) {
268 	    /* Verify the frame format.  */
269 	    if (!(CPU_IS_060 || CPU_IS_COLDFIRE) &&
270 		 (sc->sc_fpstate[0] != fpu_version))
271 		goto out;
272 	    if (CPU_IS_020_OR_030) {
273 		if (m68k_fputype & FPU_68881 &&
274 		    !(sc->sc_fpstate[1] == 0x18 || sc->sc_fpstate[1] == 0xb4))
275 		    goto out;
276 		if (m68k_fputype & FPU_68882 &&
277 		    !(sc->sc_fpstate[1] == 0x38 || sc->sc_fpstate[1] == 0xd4))
278 		    goto out;
279 	    } else if (CPU_IS_040) {
280 		if (!(sc->sc_fpstate[1] == 0x00 ||
281                       sc->sc_fpstate[1] == 0x28 ||
282                       sc->sc_fpstate[1] == 0x60))
283 		    goto out;
284 	    } else if (CPU_IS_060) {
285 		if (!(sc->sc_fpstate[3] == 0x00 ||
286                       sc->sc_fpstate[3] == 0x60 ||
287 		      sc->sc_fpstate[3] == 0xe0))
288 		    goto out;
289 	    } else if (CPU_IS_COLDFIRE) {
290 		if (!(sc->sc_fpstate[0] == 0x00 ||
291 		      sc->sc_fpstate[0] == 0x05 ||
292 		      sc->sc_fpstate[0] == 0xe5))
293 		    goto out;
294 	    } else
295 		goto out;
296 
297 	    if (CPU_IS_COLDFIRE) {
298 		__asm__ volatile ("fmovemd %0,%%fp0-%%fp1\n\t"
299 				  "fmovel %1,%%fpcr\n\t"
300 				  "fmovel %2,%%fpsr\n\t"
301 				  "fmovel %3,%%fpiar"
302 				  : /* no outputs */
303 				  : "m" (sc->sc_fpregs[0]),
304 				    "m" (sc->sc_fpcntl[0]),
305 				    "m" (sc->sc_fpcntl[1]),
306 				    "m" (sc->sc_fpcntl[2]));
307 	    } else {
308 		__asm__ volatile (".chip 68k/68881\n\t"
309 				  "fmovemx %0,%%fp0-%%fp1\n\t"
310 				  "fmoveml %1,%%fpcr/%%fpsr/%%fpiar\n\t"
311 				  ".chip 68k"
312 				  : /* no outputs */
313 				  : "m" (*sc->sc_fpregs),
314 				    "m" (*sc->sc_fpcntl));
315 	    }
316 	}
317 
318 	if (CPU_IS_COLDFIRE) {
319 		__asm__ volatile ("frestore %0" : : "m" (*sc->sc_fpstate));
320 	} else {
321 		__asm__ volatile (".chip 68k/68881\n\t"
322 				  "frestore %0\n\t"
323 				  ".chip 68k"
324 				  : : "m" (*sc->sc_fpstate));
325 	}
326 	err = 0;
327 
328 out:
329 	return err;
330 }
331 
332 static inline int rt_restore_fpu_state(struct ucontext __user *uc)
333 {
334 	unsigned char fpstate[FPCONTEXT_SIZE];
335 	int context_size = CPU_IS_060 ? 8 : (CPU_IS_COLDFIRE ? 12 : 0);
336 	fpregset_t fpregs;
337 	int err = 1;
338 
339 	if (FPU_IS_EMU) {
340 		/* restore fpu control register */
341 		if (__copy_from_user(current->thread.fpcntl,
342 				uc->uc_mcontext.fpregs.f_fpcntl, 12))
343 			goto out;
344 		/* restore all other fpu register */
345 		if (__copy_from_user(current->thread.fp,
346 				uc->uc_mcontext.fpregs.f_fpregs, 96))
347 			goto out;
348 		return 0;
349 	}
350 
351 	if (__get_user(*(long *)fpstate, (long __user *)&uc->uc_fpstate))
352 		goto out;
353 	if (CPU_IS_060 ? fpstate[2] : fpstate[0]) {
354 		if (!(CPU_IS_060 || CPU_IS_COLDFIRE))
355 			context_size = fpstate[1];
356 		/* Verify the frame format.  */
357 		if (!(CPU_IS_060 || CPU_IS_COLDFIRE) &&
358 		     (fpstate[0] != fpu_version))
359 			goto out;
360 		if (CPU_IS_020_OR_030) {
361 			if (m68k_fputype & FPU_68881 &&
362 			    !(context_size == 0x18 || context_size == 0xb4))
363 				goto out;
364 			if (m68k_fputype & FPU_68882 &&
365 			    !(context_size == 0x38 || context_size == 0xd4))
366 				goto out;
367 		} else if (CPU_IS_040) {
368 			if (!(context_size == 0x00 ||
369 			      context_size == 0x28 ||
370 			      context_size == 0x60))
371 				goto out;
372 		} else if (CPU_IS_060) {
373 			if (!(fpstate[3] == 0x00 ||
374 			      fpstate[3] == 0x60 ||
375 			      fpstate[3] == 0xe0))
376 				goto out;
377 		} else if (CPU_IS_COLDFIRE) {
378 			if (!(fpstate[3] == 0x00 ||
379 			      fpstate[3] == 0x05 ||
380 			      fpstate[3] == 0xe5))
381 				goto out;
382 		} else
383 			goto out;
384 		if (__copy_from_user(&fpregs, &uc->uc_mcontext.fpregs,
385 				     sizeof(fpregs)))
386 			goto out;
387 
388 		if (CPU_IS_COLDFIRE) {
389 			__asm__ volatile ("fmovemd %0,%%fp0-%%fp7\n\t"
390 					  "fmovel %1,%%fpcr\n\t"
391 					  "fmovel %2,%%fpsr\n\t"
392 					  "fmovel %3,%%fpiar"
393 					  : /* no outputs */
394 					  : "m" (fpregs.f_fpregs[0]),
395 					    "m" (fpregs.f_fpcntl[0]),
396 					    "m" (fpregs.f_fpcntl[1]),
397 					    "m" (fpregs.f_fpcntl[2]));
398 		} else {
399 			__asm__ volatile (".chip 68k/68881\n\t"
400 					  "fmovemx %0,%%fp0-%%fp7\n\t"
401 					  "fmoveml %1,%%fpcr/%%fpsr/%%fpiar\n\t"
402 					  ".chip 68k"
403 					  : /* no outputs */
404 					  : "m" (*fpregs.f_fpregs),
405 					    "m" (*fpregs.f_fpcntl));
406 		}
407 	}
408 	if (context_size &&
409 	    __copy_from_user(fpstate + 4, (long __user *)&uc->uc_fpstate + 1,
410 			     context_size))
411 		goto out;
412 
413 	if (CPU_IS_COLDFIRE) {
414 		__asm__ volatile ("frestore %0" : : "m" (*fpstate));
415 	} else {
416 		__asm__ volatile (".chip 68k/68881\n\t"
417 				  "frestore %0\n\t"
418 				  ".chip 68k"
419 				  : : "m" (*fpstate));
420 	}
421 	err = 0;
422 
423 out:
424 	return err;
425 }
426 
427 /*
428  * Set up a signal frame.
429  */
430 static inline void save_fpu_state(struct sigcontext *sc, struct pt_regs *regs)
431 {
432 	if (FPU_IS_EMU) {
433 		/* save registers */
434 		memcpy(sc->sc_fpcntl, current->thread.fpcntl, 12);
435 		memcpy(sc->sc_fpregs, current->thread.fp, 24);
436 		return;
437 	}
438 
439 	if (CPU_IS_COLDFIRE) {
440 		__asm__ volatile ("fsave %0"
441 				  : : "m" (*sc->sc_fpstate) : "memory");
442 	} else {
443 		__asm__ volatile (".chip 68k/68881\n\t"
444 				  "fsave %0\n\t"
445 				  ".chip 68k"
446 				  : : "m" (*sc->sc_fpstate) : "memory");
447 	}
448 
449 	if (CPU_IS_060 ? sc->sc_fpstate[2] : sc->sc_fpstate[0]) {
450 		fpu_version = sc->sc_fpstate[0];
451 		if (CPU_IS_020_OR_030 &&
452 		    regs->vector >= (VEC_FPBRUC * 4) &&
453 		    regs->vector <= (VEC_FPNAN * 4)) {
454 			/* Clear pending exception in 68882 idle frame */
455 			if (*(unsigned short *) sc->sc_fpstate == 0x1f38)
456 				sc->sc_fpstate[0x38] |= 1 << 3;
457 		}
458 
459 		if (CPU_IS_COLDFIRE) {
460 			__asm__ volatile ("fmovemd %%fp0-%%fp1,%0\n\t"
461 					  "fmovel %%fpcr,%1\n\t"
462 					  "fmovel %%fpsr,%2\n\t"
463 					  "fmovel %%fpiar,%3"
464 					  : "=m" (sc->sc_fpregs[0]),
465 					    "=m" (sc->sc_fpcntl[0]),
466 					    "=m" (sc->sc_fpcntl[1]),
467 					    "=m" (sc->sc_fpcntl[2])
468 					  : /* no inputs */
469 					  : "memory");
470 		} else {
471 			__asm__ volatile (".chip 68k/68881\n\t"
472 					  "fmovemx %%fp0-%%fp1,%0\n\t"
473 					  "fmoveml %%fpcr/%%fpsr/%%fpiar,%1\n\t"
474 					  ".chip 68k"
475 					  : "=m" (*sc->sc_fpregs),
476 					    "=m" (*sc->sc_fpcntl)
477 					  : /* no inputs */
478 					  : "memory");
479 		}
480 	}
481 }
482 
483 static inline int rt_save_fpu_state(struct ucontext __user *uc, struct pt_regs *regs)
484 {
485 	unsigned char fpstate[FPCONTEXT_SIZE];
486 	int context_size = CPU_IS_060 ? 8 : (CPU_IS_COLDFIRE ? 12 : 0);
487 	int err = 0;
488 
489 	if (FPU_IS_EMU) {
490 		/* save fpu control register */
491 		err |= copy_to_user(uc->uc_mcontext.fpregs.f_fpcntl,
492 				current->thread.fpcntl, 12);
493 		/* save all other fpu register */
494 		err |= copy_to_user(uc->uc_mcontext.fpregs.f_fpregs,
495 				current->thread.fp, 96);
496 		return err;
497 	}
498 
499 	if (CPU_IS_COLDFIRE) {
500 		__asm__ volatile ("fsave %0" : : "m" (*fpstate) : "memory");
501 	} else {
502 		__asm__ volatile (".chip 68k/68881\n\t"
503 				  "fsave %0\n\t"
504 				  ".chip 68k"
505 				  : : "m" (*fpstate) : "memory");
506 	}
507 
508 	err |= __put_user(*(long *)fpstate, (long __user *)&uc->uc_fpstate);
509 	if (CPU_IS_060 ? fpstate[2] : fpstate[0]) {
510 		fpregset_t fpregs;
511 		if (!(CPU_IS_060 || CPU_IS_COLDFIRE))
512 			context_size = fpstate[1];
513 		fpu_version = fpstate[0];
514 		if (CPU_IS_020_OR_030 &&
515 		    regs->vector >= (VEC_FPBRUC * 4) &&
516 		    regs->vector <= (VEC_FPNAN * 4)) {
517 			/* Clear pending exception in 68882 idle frame */
518 			if (*(unsigned short *) fpstate == 0x1f38)
519 				fpstate[0x38] |= 1 << 3;
520 		}
521 		if (CPU_IS_COLDFIRE) {
522 			__asm__ volatile ("fmovemd %%fp0-%%fp7,%0\n\t"
523 					  "fmovel %%fpcr,%1\n\t"
524 					  "fmovel %%fpsr,%2\n\t"
525 					  "fmovel %%fpiar,%3"
526 					  : "=m" (fpregs.f_fpregs[0]),
527 					    "=m" (fpregs.f_fpcntl[0]),
528 					    "=m" (fpregs.f_fpcntl[1]),
529 					    "=m" (fpregs.f_fpcntl[2])
530 					  : /* no inputs */
531 					  : "memory");
532 		} else {
533 			__asm__ volatile (".chip 68k/68881\n\t"
534 					  "fmovemx %%fp0-%%fp7,%0\n\t"
535 					  "fmoveml %%fpcr/%%fpsr/%%fpiar,%1\n\t"
536 					  ".chip 68k"
537 					  : "=m" (*fpregs.f_fpregs),
538 					    "=m" (*fpregs.f_fpcntl)
539 					  : /* no inputs */
540 					  : "memory");
541 		}
542 		err |= copy_to_user(&uc->uc_mcontext.fpregs, &fpregs,
543 				    sizeof(fpregs));
544 	}
545 	if (context_size)
546 		err |= copy_to_user((long __user *)&uc->uc_fpstate + 1, fpstate + 4,
547 				    context_size);
548 	return err;
549 }
550 
551 #else /* CONFIG_FPU */
552 
553 /*
554  * For the case with no FPU configured these all do nothing.
555  */
556 static inline int restore_fpu_state(struct sigcontext *sc)
557 {
558 	return 0;
559 }
560 
561 static inline int rt_restore_fpu_state(struct ucontext __user *uc)
562 {
563 	return 0;
564 }
565 
566 static inline void save_fpu_state(struct sigcontext *sc, struct pt_regs *regs)
567 {
568 }
569 
570 static inline int rt_save_fpu_state(struct ucontext __user *uc, struct pt_regs *regs)
571 {
572 	return 0;
573 }
574 
575 #endif /* CONFIG_FPU */
576 
577 static inline void siginfo_build_tests(void)
578 {
579 	/* This needs to be tested on m68k as it has a lesser
580 	 * alignment requirment than x86 and that can cause surprises.
581 	 */
582 
583 	/* This is part of the ABI and can never change in size: */
584 	BUILD_BUG_ON(sizeof(siginfo_t) != 128);
585 
586 	/* Ensure the know fields never change in location */
587 	BUILD_BUG_ON(offsetof(siginfo_t, si_signo) != 0);
588 	BUILD_BUG_ON(offsetof(siginfo_t, si_errno) != 4);
589 	BUILD_BUG_ON(offsetof(siginfo_t, si_code)  != 8);
590 
591 	/* _kill */
592 	BUILD_BUG_ON(offsetof(siginfo_t, si_pid) != 0x0C);
593 	BUILD_BUG_ON(offsetof(siginfo_t, si_uid) != 0x10);
594 
595 	/* _timer */
596 	BUILD_BUG_ON(offsetof(siginfo_t, si_tid)     != 0x0C);
597 	BUILD_BUG_ON(offsetof(siginfo_t, si_overrun) != 0x10);
598 	BUILD_BUG_ON(offsetof(siginfo_t, si_value)   != 0x14);
599 
600 	/* _rt */
601 	BUILD_BUG_ON(offsetof(siginfo_t, si_pid)   != 0x0C);
602 	BUILD_BUG_ON(offsetof(siginfo_t, si_uid)   != 0x10);
603 	BUILD_BUG_ON(offsetof(siginfo_t, si_value) != 0x14);
604 
605 	/* _sigchld */
606 	BUILD_BUG_ON(offsetof(siginfo_t, si_pid)    != 0x0C);
607 	BUILD_BUG_ON(offsetof(siginfo_t, si_uid)    != 0x10);
608 	BUILD_BUG_ON(offsetof(siginfo_t, si_status) != 0x14);
609 	BUILD_BUG_ON(offsetof(siginfo_t, si_utime)  != 0x18);
610 	BUILD_BUG_ON(offsetof(siginfo_t, si_stime)  != 0x1C);
611 
612 	/* _sigfault */
613 	BUILD_BUG_ON(offsetof(siginfo_t, si_addr) != 0x0C);
614 
615 	/* _sigfault._mcerr */
616 	BUILD_BUG_ON(offsetof(siginfo_t, si_addr_lsb) != 0x10);
617 
618 	/* _sigfault._addr_bnd */
619 	BUILD_BUG_ON(offsetof(siginfo_t, si_lower) != 0x12);
620 	BUILD_BUG_ON(offsetof(siginfo_t, si_upper) != 0x16);
621 
622 	/* _sigfault._addr_pkey */
623 	BUILD_BUG_ON(offsetof(siginfo_t, si_pkey) != 0x12);
624 
625 	/* _sigpoll */
626 	BUILD_BUG_ON(offsetof(siginfo_t, si_band)   != 0x0C);
627 	BUILD_BUG_ON(offsetof(siginfo_t, si_fd)     != 0x10);
628 
629 	/* _sigsys */
630 	BUILD_BUG_ON(offsetof(siginfo_t, si_call_addr) != 0x0C);
631 	BUILD_BUG_ON(offsetof(siginfo_t, si_syscall)   != 0x10);
632 	BUILD_BUG_ON(offsetof(siginfo_t, si_arch)      != 0x14);
633 
634 	/* any new si_fields should be added here */
635 }
636 
637 static int mangle_kernel_stack(struct pt_regs *regs, int formatvec,
638 			       void __user *fp)
639 {
640 	int fsize = frame_extra_sizes(formatvec >> 12);
641 	if (fsize < 0) {
642 		/*
643 		 * user process trying to return with weird frame format
644 		 */
645 		pr_debug("user process returning with weird frame format\n");
646 		return 1;
647 	}
648 	if (!fsize) {
649 		regs->format = formatvec >> 12;
650 		regs->vector = formatvec & 0xfff;
651 	} else {
652 		struct switch_stack *sw = (struct switch_stack *)regs - 1;
653 		unsigned long buf[fsize / 2]; /* yes, twice as much */
654 
655 		/* that'll make sure that expansion won't crap over data */
656 		if (copy_from_user(buf + fsize / 4, fp, fsize))
657 			return 1;
658 
659 		/* point of no return */
660 		regs->format = formatvec >> 12;
661 		regs->vector = formatvec & 0xfff;
662 #define frame_offset (sizeof(struct pt_regs)+sizeof(struct switch_stack))
663 		__asm__ __volatile__ (
664 #ifdef CONFIG_COLDFIRE
665 			 "   movel %0,%/sp\n\t"
666 			 "   bra ret_from_signal\n"
667 #else
668 			 "   movel %0,%/a0\n\t"
669 			 "   subl %1,%/a0\n\t"     /* make room on stack */
670 			 "   movel %/a0,%/sp\n\t"  /* set stack pointer */
671 			 /* move switch_stack and pt_regs */
672 			 "1: movel %0@+,%/a0@+\n\t"
673 			 "   dbra %2,1b\n\t"
674 			 "   lea %/sp@(%c3),%/a0\n\t" /* add offset of fmt */
675 			 "   lsrl  #2,%1\n\t"
676 			 "   subql #1,%1\n\t"
677 			 /* copy to the gap we'd made */
678 			 "2: movel %4@+,%/a0@+\n\t"
679 			 "   dbra %1,2b\n\t"
680 			 "   bral ret_from_signal\n"
681 #endif
682 			 : /* no outputs, it doesn't ever return */
683 			 : "a" (sw), "d" (fsize), "d" (frame_offset/4-1),
684 			   "n" (frame_offset), "a" (buf + fsize/4)
685 			 : "a0");
686 #undef frame_offset
687 	}
688 	return 0;
689 }
690 
691 static inline int
692 restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *usc, void __user *fp)
693 {
694 	int formatvec;
695 	struct sigcontext context;
696 	int err = 0;
697 
698 	siginfo_build_tests();
699 
700 	/* Always make any pending restarted system calls return -EINTR */
701 	current->restart_block.fn = do_no_restart_syscall;
702 
703 	/* get previous context */
704 	if (copy_from_user(&context, usc, sizeof(context)))
705 		goto badframe;
706 
707 	/* restore passed registers */
708 	regs->d0 = context.sc_d0;
709 	regs->d1 = context.sc_d1;
710 	regs->a0 = context.sc_a0;
711 	regs->a1 = context.sc_a1;
712 	regs->sr = (regs->sr & 0xff00) | (context.sc_sr & 0xff);
713 	regs->pc = context.sc_pc;
714 	regs->orig_d0 = -1;		/* disable syscall checks */
715 	wrusp(context.sc_usp);
716 	formatvec = context.sc_formatvec;
717 
718 	err = restore_fpu_state(&context);
719 
720 	if (err || mangle_kernel_stack(regs, formatvec, fp))
721 		goto badframe;
722 
723 	return 0;
724 
725 badframe:
726 	return 1;
727 }
728 
729 static inline int
730 rt_restore_ucontext(struct pt_regs *regs, struct switch_stack *sw,
731 		    struct ucontext __user *uc)
732 {
733 	int temp;
734 	greg_t __user *gregs = uc->uc_mcontext.gregs;
735 	unsigned long usp;
736 	int err;
737 
738 	/* Always make any pending restarted system calls return -EINTR */
739 	current->restart_block.fn = do_no_restart_syscall;
740 
741 	err = __get_user(temp, &uc->uc_mcontext.version);
742 	if (temp != MCONTEXT_VERSION)
743 		goto badframe;
744 	/* restore passed registers */
745 	err |= __get_user(regs->d0, &gregs[0]);
746 	err |= __get_user(regs->d1, &gregs[1]);
747 	err |= __get_user(regs->d2, &gregs[2]);
748 	err |= __get_user(regs->d3, &gregs[3]);
749 	err |= __get_user(regs->d4, &gregs[4]);
750 	err |= __get_user(regs->d5, &gregs[5]);
751 	err |= __get_user(sw->d6, &gregs[6]);
752 	err |= __get_user(sw->d7, &gregs[7]);
753 	err |= __get_user(regs->a0, &gregs[8]);
754 	err |= __get_user(regs->a1, &gregs[9]);
755 	err |= __get_user(regs->a2, &gregs[10]);
756 	err |= __get_user(sw->a3, &gregs[11]);
757 	err |= __get_user(sw->a4, &gregs[12]);
758 	err |= __get_user(sw->a5, &gregs[13]);
759 	err |= __get_user(sw->a6, &gregs[14]);
760 	err |= __get_user(usp, &gregs[15]);
761 	wrusp(usp);
762 	err |= __get_user(regs->pc, &gregs[16]);
763 	err |= __get_user(temp, &gregs[17]);
764 	regs->sr = (regs->sr & 0xff00) | (temp & 0xff);
765 	regs->orig_d0 = -1;		/* disable syscall checks */
766 	err |= __get_user(temp, &uc->uc_formatvec);
767 
768 	err |= rt_restore_fpu_state(uc);
769 	err |= restore_altstack(&uc->uc_stack);
770 
771 	if (err)
772 		goto badframe;
773 
774 	if (mangle_kernel_stack(regs, temp, &uc->uc_extra))
775 		goto badframe;
776 
777 	return 0;
778 
779 badframe:
780 	return 1;
781 }
782 
783 asmlinkage int do_sigreturn(struct pt_regs *regs, struct switch_stack *sw)
784 {
785 	unsigned long usp = rdusp();
786 	struct sigframe __user *frame = (struct sigframe __user *)(usp - 4);
787 	sigset_t set;
788 
789 	if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
790 		goto badframe;
791 	if (__get_user(set.sig[0], &frame->sc.sc_mask) ||
792 	    (_NSIG_WORDS > 1 &&
793 	     __copy_from_user(&set.sig[1], &frame->extramask,
794 			      sizeof(frame->extramask))))
795 		goto badframe;
796 
797 	set_current_blocked(&set);
798 
799 	if (restore_sigcontext(regs, &frame->sc, frame + 1))
800 		goto badframe;
801 	return regs->d0;
802 
803 badframe:
804 	force_sig(SIGSEGV, current);
805 	return 0;
806 }
807 
808 asmlinkage int do_rt_sigreturn(struct pt_regs *regs, struct switch_stack *sw)
809 {
810 	unsigned long usp = rdusp();
811 	struct rt_sigframe __user *frame = (struct rt_sigframe __user *)(usp - 4);
812 	sigset_t set;
813 
814 	if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
815 		goto badframe;
816 	if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set)))
817 		goto badframe;
818 
819 	set_current_blocked(&set);
820 
821 	if (rt_restore_ucontext(regs, sw, &frame->uc))
822 		goto badframe;
823 	return regs->d0;
824 
825 badframe:
826 	force_sig(SIGSEGV, current);
827 	return 0;
828 }
829 
830 static void setup_sigcontext(struct sigcontext *sc, struct pt_regs *regs,
831 			     unsigned long mask)
832 {
833 	sc->sc_mask = mask;
834 	sc->sc_usp = rdusp();
835 	sc->sc_d0 = regs->d0;
836 	sc->sc_d1 = regs->d1;
837 	sc->sc_a0 = regs->a0;
838 	sc->sc_a1 = regs->a1;
839 	sc->sc_sr = regs->sr;
840 	sc->sc_pc = regs->pc;
841 	sc->sc_formatvec = regs->format << 12 | regs->vector;
842 	save_a5_state(sc, regs);
843 	save_fpu_state(sc, regs);
844 }
845 
846 static inline int rt_setup_ucontext(struct ucontext __user *uc, struct pt_regs *regs)
847 {
848 	struct switch_stack *sw = (struct switch_stack *)regs - 1;
849 	greg_t __user *gregs = uc->uc_mcontext.gregs;
850 	int err = 0;
851 
852 	err |= __put_user(MCONTEXT_VERSION, &uc->uc_mcontext.version);
853 	err |= __put_user(regs->d0, &gregs[0]);
854 	err |= __put_user(regs->d1, &gregs[1]);
855 	err |= __put_user(regs->d2, &gregs[2]);
856 	err |= __put_user(regs->d3, &gregs[3]);
857 	err |= __put_user(regs->d4, &gregs[4]);
858 	err |= __put_user(regs->d5, &gregs[5]);
859 	err |= __put_user(sw->d6, &gregs[6]);
860 	err |= __put_user(sw->d7, &gregs[7]);
861 	err |= __put_user(regs->a0, &gregs[8]);
862 	err |= __put_user(regs->a1, &gregs[9]);
863 	err |= __put_user(regs->a2, &gregs[10]);
864 	err |= __put_user(sw->a3, &gregs[11]);
865 	err |= __put_user(sw->a4, &gregs[12]);
866 	err |= __put_user(sw->a5, &gregs[13]);
867 	err |= __put_user(sw->a6, &gregs[14]);
868 	err |= __put_user(rdusp(), &gregs[15]);
869 	err |= __put_user(regs->pc, &gregs[16]);
870 	err |= __put_user(regs->sr, &gregs[17]);
871 	err |= __put_user((regs->format << 12) | regs->vector, &uc->uc_formatvec);
872 	err |= rt_save_fpu_state(uc, regs);
873 	return err;
874 }
875 
876 static inline void __user *
877 get_sigframe(struct ksignal *ksig, size_t frame_size)
878 {
879 	unsigned long usp = sigsp(rdusp(), ksig);
880 
881 	return (void __user *)((usp - frame_size) & -8UL);
882 }
883 
884 static int setup_frame(struct ksignal *ksig, sigset_t *set,
885 			struct pt_regs *regs)
886 {
887 	struct sigframe __user *frame;
888 	int fsize = frame_extra_sizes(regs->format);
889 	struct sigcontext context;
890 	int err = 0, sig = ksig->sig;
891 
892 	if (fsize < 0) {
893 		pr_debug("setup_frame: Unknown frame format %#x\n",
894 			 regs->format);
895 		return -EFAULT;
896 	}
897 
898 	frame = get_sigframe(ksig, sizeof(*frame) + fsize);
899 
900 	if (fsize)
901 		err |= copy_to_user (frame + 1, regs + 1, fsize);
902 
903 	err |= __put_user(sig, &frame->sig);
904 
905 	err |= __put_user(regs->vector, &frame->code);
906 	err |= __put_user(&frame->sc, &frame->psc);
907 
908 	if (_NSIG_WORDS > 1)
909 		err |= copy_to_user(frame->extramask, &set->sig[1],
910 				    sizeof(frame->extramask));
911 
912 	setup_sigcontext(&context, regs, set->sig[0]);
913 	err |= copy_to_user (&frame->sc, &context, sizeof(context));
914 
915 	/* Set up to return from userspace.  */
916 #ifdef CONFIG_MMU
917 	err |= __put_user(frame->retcode, &frame->pretcode);
918 	/* moveq #,d0; trap #0 */
919 	err |= __put_user(0x70004e40 + (__NR_sigreturn << 16),
920 			  (long __user *)(frame->retcode));
921 #else
922 	err |= __put_user((void *) ret_from_user_signal, &frame->pretcode);
923 #endif
924 
925 	if (err)
926 		return -EFAULT;
927 
928 	push_cache ((unsigned long) &frame->retcode);
929 
930 	/*
931 	 * Set up registers for signal handler.  All the state we are about
932 	 * to destroy is successfully copied to sigframe.
933 	 */
934 	wrusp ((unsigned long) frame);
935 	regs->pc = (unsigned long) ksig->ka.sa.sa_handler;
936 	adjustformat(regs);
937 
938 	/*
939 	 * This is subtle; if we build more than one sigframe, all but the
940 	 * first one will see frame format 0 and have fsize == 0, so we won't
941 	 * screw stkadj.
942 	 */
943 	if (fsize)
944 		regs->stkadj = fsize;
945 
946 	/* Prepare to skip over the extra stuff in the exception frame.  */
947 	if (regs->stkadj) {
948 		struct pt_regs *tregs =
949 			(struct pt_regs *)((ulong)regs + regs->stkadj);
950 		pr_debug("Performing stackadjust=%04lx\n", regs->stkadj);
951 		/* This must be copied with decreasing addresses to
952                    handle overlaps.  */
953 		tregs->vector = 0;
954 		tregs->format = 0;
955 		tregs->pc = regs->pc;
956 		tregs->sr = regs->sr;
957 	}
958 	return 0;
959 }
960 
961 static int setup_rt_frame(struct ksignal *ksig, sigset_t *set,
962 			   struct pt_regs *regs)
963 {
964 	struct rt_sigframe __user *frame;
965 	int fsize = frame_extra_sizes(regs->format);
966 	int err = 0, sig = ksig->sig;
967 
968 	if (fsize < 0) {
969 		pr_debug("setup_frame: Unknown frame format %#x\n",
970 			 regs->format);
971 		return -EFAULT;
972 	}
973 
974 	frame = get_sigframe(ksig, sizeof(*frame));
975 
976 	if (fsize)
977 		err |= copy_to_user (&frame->uc.uc_extra, regs + 1, fsize);
978 
979 	err |= __put_user(sig, &frame->sig);
980 	err |= __put_user(&frame->info, &frame->pinfo);
981 	err |= __put_user(&frame->uc, &frame->puc);
982 	err |= copy_siginfo_to_user(&frame->info, &ksig->info);
983 
984 	/* Create the ucontext.  */
985 	err |= __put_user(0, &frame->uc.uc_flags);
986 	err |= __put_user(NULL, &frame->uc.uc_link);
987 	err |= __save_altstack(&frame->uc.uc_stack, rdusp());
988 	err |= rt_setup_ucontext(&frame->uc, regs);
989 	err |= copy_to_user (&frame->uc.uc_sigmask, set, sizeof(*set));
990 
991 	/* Set up to return from userspace.  */
992 #ifdef CONFIG_MMU
993 	err |= __put_user(frame->retcode, &frame->pretcode);
994 #ifdef __mcoldfire__
995 	/* movel #__NR_rt_sigreturn,d0; trap #0 */
996 	err |= __put_user(0x203c0000, (long __user *)(frame->retcode + 0));
997 	err |= __put_user(0x00004e40 + (__NR_rt_sigreturn << 16),
998 			  (long __user *)(frame->retcode + 4));
999 #else
1000 	/* moveq #,d0; notb d0; trap #0 */
1001 	err |= __put_user(0x70004600 + ((__NR_rt_sigreturn ^ 0xff) << 16),
1002 			  (long __user *)(frame->retcode + 0));
1003 	err |= __put_user(0x4e40, (short __user *)(frame->retcode + 4));
1004 #endif
1005 #else
1006 	err |= __put_user((void *) ret_from_user_rt_signal, &frame->pretcode);
1007 #endif /* CONFIG_MMU */
1008 
1009 	if (err)
1010 		return -EFAULT;
1011 
1012 	push_cache ((unsigned long) &frame->retcode);
1013 
1014 	/*
1015 	 * Set up registers for signal handler.  All the state we are about
1016 	 * to destroy is successfully copied to sigframe.
1017 	 */
1018 	wrusp ((unsigned long) frame);
1019 	regs->pc = (unsigned long) ksig->ka.sa.sa_handler;
1020 	adjustformat(regs);
1021 
1022 	/*
1023 	 * This is subtle; if we build more than one sigframe, all but the
1024 	 * first one will see frame format 0 and have fsize == 0, so we won't
1025 	 * screw stkadj.
1026 	 */
1027 	if (fsize)
1028 		regs->stkadj = fsize;
1029 
1030 	/* Prepare to skip over the extra stuff in the exception frame.  */
1031 	if (regs->stkadj) {
1032 		struct pt_regs *tregs =
1033 			(struct pt_regs *)((ulong)regs + regs->stkadj);
1034 		pr_debug("Performing stackadjust=%04lx\n", regs->stkadj);
1035 		/* This must be copied with decreasing addresses to
1036                    handle overlaps.  */
1037 		tregs->vector = 0;
1038 		tregs->format = 0;
1039 		tregs->pc = regs->pc;
1040 		tregs->sr = regs->sr;
1041 	}
1042 	return 0;
1043 }
1044 
1045 static inline void
1046 handle_restart(struct pt_regs *regs, struct k_sigaction *ka, int has_handler)
1047 {
1048 	switch (regs->d0) {
1049 	case -ERESTARTNOHAND:
1050 		if (!has_handler)
1051 			goto do_restart;
1052 		regs->d0 = -EINTR;
1053 		break;
1054 
1055 	case -ERESTART_RESTARTBLOCK:
1056 		if (!has_handler) {
1057 			regs->d0 = __NR_restart_syscall;
1058 			regs->pc -= 2;
1059 			break;
1060 		}
1061 		regs->d0 = -EINTR;
1062 		break;
1063 
1064 	case -ERESTARTSYS:
1065 		if (has_handler && !(ka->sa.sa_flags & SA_RESTART)) {
1066 			regs->d0 = -EINTR;
1067 			break;
1068 		}
1069 	/* fallthrough */
1070 	case -ERESTARTNOINTR:
1071 	do_restart:
1072 		regs->d0 = regs->orig_d0;
1073 		regs->pc -= 2;
1074 		break;
1075 	}
1076 }
1077 
1078 /*
1079  * OK, we're invoking a handler
1080  */
1081 static void
1082 handle_signal(struct ksignal *ksig, struct pt_regs *regs)
1083 {
1084 	sigset_t *oldset = sigmask_to_save();
1085 	int err;
1086 	/* are we from a system call? */
1087 	if (regs->orig_d0 >= 0)
1088 		/* If so, check system call restarting.. */
1089 		handle_restart(regs, &ksig->ka, 1);
1090 
1091 	/* set up the stack frame */
1092 	if (ksig->ka.sa.sa_flags & SA_SIGINFO)
1093 		err = setup_rt_frame(ksig, oldset, regs);
1094 	else
1095 		err = setup_frame(ksig, oldset, regs);
1096 
1097 	signal_setup_done(err, ksig, 0);
1098 
1099 	if (test_thread_flag(TIF_DELAYED_TRACE)) {
1100 		regs->sr &= ~0x8000;
1101 		send_sig(SIGTRAP, current, 1);
1102 	}
1103 }
1104 
1105 /*
1106  * Note that 'init' is a special process: it doesn't get signals it doesn't
1107  * want to handle. Thus you cannot kill init even with a SIGKILL even by
1108  * mistake.
1109  */
1110 static void do_signal(struct pt_regs *regs)
1111 {
1112 	struct ksignal ksig;
1113 
1114 	current->thread.esp0 = (unsigned long) regs;
1115 
1116 	if (get_signal(&ksig)) {
1117 		/* Whee!  Actually deliver the signal.  */
1118 		handle_signal(&ksig, regs);
1119 		return;
1120 	}
1121 
1122 	/* Did we come from a system call? */
1123 	if (regs->orig_d0 >= 0)
1124 		/* Restart the system call - no handlers present */
1125 		handle_restart(regs, NULL, 0);
1126 
1127 	/* If there's no signal to deliver, we just restore the saved mask.  */
1128 	restore_saved_sigmask();
1129 }
1130 
1131 void do_notify_resume(struct pt_regs *regs)
1132 {
1133 	if (test_thread_flag(TIF_SIGPENDING))
1134 		do_signal(regs);
1135 
1136 	if (test_and_clear_thread_flag(TIF_NOTIFY_RESUME))
1137 		tracehook_notify_resume(regs);
1138 }
1139