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
68static 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
86static inline int frame_extra_sizes(int f)
87{
88	return frame_size_change[f];
89}
90
91int 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
112void 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
128static 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
195static inline void adjustformat(struct pt_regs *regs)
196{
197}
198
199static inline void save_a5_state(struct sigcontext *sc, struct pt_regs *regs)
200{
201}
202
203#else /* CONFIG_MMU */
204
205void ret_from_user_signal(void);
206void ret_from_user_rt_signal(void);
207
208static inline int frame_extra_sizes(int f)
209{
210	/* No frame size adjustments required on non-MMU CPUs */
211	return 0;
212}
213
214static 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
224static 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
229static 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
242struct 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
253struct 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
271static unsigned char fpu_version;	/* version number of fpu, set by setup_frame */
272
273static 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
345out:
346	return err;
347}
348
349static 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
440out:
441	return err;
442}
443
444/*
445 * Set up a signal frame.
446 */
447static 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
500static 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 */
573static inline int restore_fpu_state(struct sigcontext *sc)
574{
575	return 0;
576}
577
578static inline int rt_restore_fpu_state(struct ucontext __user *uc)
579{
580	return 0;
581}
582
583static inline void save_fpu_state(struct sigcontext *sc, struct pt_regs *regs)
584{
585}
586
587static 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
594static 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
650static inline int
651restore_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_thread_info()->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
682badframe:
683	return 1;
684}
685
686static inline int
687rt_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_thread_info()->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
736badframe:
737	return 1;
738}
739
740asmlinkage 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
762badframe:
763	force_sig(SIGSEGV, current);
764	return 0;
765}
766
767asmlinkage 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
786badframe:
787	force_sig(SIGSEGV, current);
788	return 0;
789}
790
791static 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
807static 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
837static inline void __user *
838get_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
845static 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((current_thread_info()->exec_domain
867			   && current_thread_info()->exec_domain->signal_invmap
868			   && sig < 32
869			   ? current_thread_info()->exec_domain->signal_invmap[sig]
870			   : sig),
871			  &frame->sig);
872
873	err |= __put_user(regs->vector, &frame->code);
874	err |= __put_user(&frame->sc, &frame->psc);
875
876	if (_NSIG_WORDS > 1)
877		err |= copy_to_user(frame->extramask, &set->sig[1],
878				    sizeof(frame->extramask));
879
880	setup_sigcontext(&context, regs, set->sig[0]);
881	err |= copy_to_user (&frame->sc, &context, sizeof(context));
882
883	/* Set up to return from userspace.  */
884#ifdef CONFIG_MMU
885	err |= __put_user(frame->retcode, &frame->pretcode);
886	/* moveq #,d0; trap #0 */
887	err |= __put_user(0x70004e40 + (__NR_sigreturn << 16),
888			  (long __user *)(frame->retcode));
889#else
890	err |= __put_user((void *) ret_from_user_signal, &frame->pretcode);
891#endif
892
893	if (err)
894		return -EFAULT;
895
896	push_cache ((unsigned long) &frame->retcode);
897
898	/*
899	 * Set up registers for signal handler.  All the state we are about
900	 * to destroy is successfully copied to sigframe.
901	 */
902	wrusp ((unsigned long) frame);
903	regs->pc = (unsigned long) ksig->ka.sa.sa_handler;
904	adjustformat(regs);
905
906	/*
907	 * This is subtle; if we build more than one sigframe, all but the
908	 * first one will see frame format 0 and have fsize == 0, so we won't
909	 * screw stkadj.
910	 */
911	if (fsize)
912		regs->stkadj = fsize;
913
914	/* Prepare to skip over the extra stuff in the exception frame.  */
915	if (regs->stkadj) {
916		struct pt_regs *tregs =
917			(struct pt_regs *)((ulong)regs + regs->stkadj);
918#ifdef DEBUG
919		printk("Performing stackadjust=%04x\n", regs->stkadj);
920#endif
921		/* This must be copied with decreasing addresses to
922                   handle overlaps.  */
923		tregs->vector = 0;
924		tregs->format = 0;
925		tregs->pc = regs->pc;
926		tregs->sr = regs->sr;
927	}
928	return 0;
929}
930
931static int setup_rt_frame(struct ksignal *ksig, sigset_t *set,
932			   struct pt_regs *regs)
933{
934	struct rt_sigframe __user *frame;
935	int fsize = frame_extra_sizes(regs->format);
936	int err = 0, sig = ksig->sig;
937
938	if (fsize < 0) {
939#ifdef DEBUG
940		printk ("setup_frame: Unknown frame format %#x\n",
941			regs->format);
942#endif
943		return -EFAULT;
944	}
945
946	frame = get_sigframe(ksig, sizeof(*frame));
947
948	if (fsize)
949		err |= copy_to_user (&frame->uc.uc_extra, regs + 1, fsize);
950
951	err |= __put_user((current_thread_info()->exec_domain
952			   && current_thread_info()->exec_domain->signal_invmap
953			   && sig < 32
954			   ? current_thread_info()->exec_domain->signal_invmap[sig]
955			   : sig),
956			  &frame->sig);
957	err |= __put_user(&frame->info, &frame->pinfo);
958	err |= __put_user(&frame->uc, &frame->puc);
959	err |= copy_siginfo_to_user(&frame->info, &ksig->info);
960
961	/* Create the ucontext.  */
962	err |= __put_user(0, &frame->uc.uc_flags);
963	err |= __put_user(NULL, &frame->uc.uc_link);
964	err |= __save_altstack(&frame->uc.uc_stack, rdusp());
965	err |= rt_setup_ucontext(&frame->uc, regs);
966	err |= copy_to_user (&frame->uc.uc_sigmask, set, sizeof(*set));
967
968	/* Set up to return from userspace.  */
969#ifdef CONFIG_MMU
970	err |= __put_user(frame->retcode, &frame->pretcode);
971#ifdef __mcoldfire__
972	/* movel #__NR_rt_sigreturn,d0; trap #0 */
973	err |= __put_user(0x203c0000, (long __user *)(frame->retcode + 0));
974	err |= __put_user(0x00004e40 + (__NR_rt_sigreturn << 16),
975			  (long __user *)(frame->retcode + 4));
976#else
977	/* moveq #,d0; notb d0; trap #0 */
978	err |= __put_user(0x70004600 + ((__NR_rt_sigreturn ^ 0xff) << 16),
979			  (long __user *)(frame->retcode + 0));
980	err |= __put_user(0x4e40, (short __user *)(frame->retcode + 4));
981#endif
982#else
983	err |= __put_user((void *) ret_from_user_rt_signal, &frame->pretcode);
984#endif /* CONFIG_MMU */
985
986	if (err)
987		return -EFAULT;
988
989	push_cache ((unsigned long) &frame->retcode);
990
991	/*
992	 * Set up registers for signal handler.  All the state we are about
993	 * to destroy is successfully copied to sigframe.
994	 */
995	wrusp ((unsigned long) frame);
996	regs->pc = (unsigned long) ksig->ka.sa.sa_handler;
997	adjustformat(regs);
998
999	/*
1000	 * This is subtle; if we build more than one sigframe, all but the
1001	 * first one will see frame format 0 and have fsize == 0, so we won't
1002	 * screw stkadj.
1003	 */
1004	if (fsize)
1005		regs->stkadj = fsize;
1006
1007	/* Prepare to skip over the extra stuff in the exception frame.  */
1008	if (regs->stkadj) {
1009		struct pt_regs *tregs =
1010			(struct pt_regs *)((ulong)regs + regs->stkadj);
1011#ifdef DEBUG
1012		printk("Performing stackadjust=%04x\n", regs->stkadj);
1013#endif
1014		/* This must be copied with decreasing addresses to
1015                   handle overlaps.  */
1016		tregs->vector = 0;
1017		tregs->format = 0;
1018		tregs->pc = regs->pc;
1019		tregs->sr = regs->sr;
1020	}
1021	return 0;
1022}
1023
1024static inline void
1025handle_restart(struct pt_regs *regs, struct k_sigaction *ka, int has_handler)
1026{
1027	switch (regs->d0) {
1028	case -ERESTARTNOHAND:
1029		if (!has_handler)
1030			goto do_restart;
1031		regs->d0 = -EINTR;
1032		break;
1033
1034	case -ERESTART_RESTARTBLOCK:
1035		if (!has_handler) {
1036			regs->d0 = __NR_restart_syscall;
1037			regs->pc -= 2;
1038			break;
1039		}
1040		regs->d0 = -EINTR;
1041		break;
1042
1043	case -ERESTARTSYS:
1044		if (has_handler && !(ka->sa.sa_flags & SA_RESTART)) {
1045			regs->d0 = -EINTR;
1046			break;
1047		}
1048	/* fallthrough */
1049	case -ERESTARTNOINTR:
1050	do_restart:
1051		regs->d0 = regs->orig_d0;
1052		regs->pc -= 2;
1053		break;
1054	}
1055}
1056
1057/*
1058 * OK, we're invoking a handler
1059 */
1060static void
1061handle_signal(struct ksignal *ksig, struct pt_regs *regs)
1062{
1063	sigset_t *oldset = sigmask_to_save();
1064	int err;
1065	/* are we from a system call? */
1066	if (regs->orig_d0 >= 0)
1067		/* If so, check system call restarting.. */
1068		handle_restart(regs, &ksig->ka, 1);
1069
1070	/* set up the stack frame */
1071	if (ksig->ka.sa.sa_flags & SA_SIGINFO)
1072		err = setup_rt_frame(ksig, oldset, regs);
1073	else
1074		err = setup_frame(ksig, oldset, regs);
1075
1076	signal_setup_done(err, ksig, 0);
1077
1078	if (test_thread_flag(TIF_DELAYED_TRACE)) {
1079		regs->sr &= ~0x8000;
1080		send_sig(SIGTRAP, current, 1);
1081	}
1082}
1083
1084/*
1085 * Note that 'init' is a special process: it doesn't get signals it doesn't
1086 * want to handle. Thus you cannot kill init even with a SIGKILL even by
1087 * mistake.
1088 */
1089static void do_signal(struct pt_regs *regs)
1090{
1091	struct ksignal ksig;
1092
1093	current->thread.esp0 = (unsigned long) regs;
1094
1095	if (get_signal(&ksig)) {
1096		/* Whee!  Actually deliver the signal.  */
1097		handle_signal(&ksig, regs);
1098		return;
1099	}
1100
1101	/* Did we come from a system call? */
1102	if (regs->orig_d0 >= 0)
1103		/* Restart the system call - no handlers present */
1104		handle_restart(regs, NULL, 0);
1105
1106	/* If there's no signal to deliver, we just restore the saved mask.  */
1107	restore_saved_sigmask();
1108}
1109
1110void do_notify_resume(struct pt_regs *regs)
1111{
1112	if (test_thread_flag(TIF_SIGPENDING))
1113		do_signal(regs);
1114
1115	if (test_and_clear_thread_flag(TIF_NOTIFY_RESUME))
1116		tracehook_notify_resume(regs);
1117}
1118