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TOMOYO Linux Cross Reference
Linux/arch/m68k/kernel/signal.c

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  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                                       : "" (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_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 
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_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 
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 k_sigaction *ka, struct pt_regs *regs, size_t frame_size)
839 {
840         unsigned long usp;
841 
842         /* Default to using normal stack.  */
843         usp = rdusp();
844 
845         /* This is the X/Open sanctioned signal stack switching.  */
846         if (ka->sa.sa_flags & SA_ONSTACK) {
847                 if (!sas_ss_flags(usp))
848                         usp = current->sas_ss_sp + current->sas_ss_size;
849         }
850         return (void __user *)((usp - frame_size) & -8UL);
851 }
852 
853 static int setup_frame (int sig, struct k_sigaction *ka,
854                          sigset_t *set, struct pt_regs *regs)
855 {
856         struct sigframe __user *frame;
857         int fsize = frame_extra_sizes(regs->format);
858         struct sigcontext context;
859         int err = 0;
860 
861         if (fsize < 0) {
862 #ifdef DEBUG
863                 printk ("setup_frame: Unknown frame format %#x\n",
864                         regs->format);
865 #endif
866                 goto give_sigsegv;
867         }
868 
869         frame = get_sigframe(ka, regs, sizeof(*frame) + fsize);
870 
871         if (fsize)
872                 err |= copy_to_user (frame + 1, regs + 1, fsize);
873 
874         err |= __put_user((current_thread_info()->exec_domain
875                            && current_thread_info()->exec_domain->signal_invmap
876                            && sig < 32
877                            ? current_thread_info()->exec_domain->signal_invmap[sig]
878                            : sig),
879                           &frame->sig);
880 
881         err |= __put_user(regs->vector, &frame->code);
882         err |= __put_user(&frame->sc, &frame->psc);
883 
884         if (_NSIG_WORDS > 1)
885                 err |= copy_to_user(frame->extramask, &set->sig[1],
886                                     sizeof(frame->extramask));
887 
888         setup_sigcontext(&context, regs, set->sig[0]);
889         err |= copy_to_user (&frame->sc, &context, sizeof(context));
890 
891         /* Set up to return from userspace.  */
892 #ifdef CONFIG_MMU
893         err |= __put_user(frame->retcode, &frame->pretcode);
894         /* moveq #,d0; trap #0 */
895         err |= __put_user(0x70004e40 + (__NR_sigreturn << 16),
896                           (long __user *)(frame->retcode));
897 #else
898         err |= __put_user((void *) ret_from_user_signal, &frame->pretcode);
899 #endif
900 
901         if (err)
902                 goto give_sigsegv;
903 
904         push_cache ((unsigned long) &frame->retcode);
905 
906         /*
907          * Set up registers for signal handler.  All the state we are about
908          * to destroy is successfully copied to sigframe.
909          */
910         wrusp ((unsigned long) frame);
911         regs->pc = (unsigned long) ka->sa.sa_handler;
912         adjustformat(regs);
913 
914         /*
915          * This is subtle; if we build more than one sigframe, all but the
916          * first one will see frame format 0 and have fsize == 0, so we won't
917          * screw stkadj.
918          */
919         if (fsize)
920                 regs->stkadj = fsize;
921 
922         /* Prepare to skip over the extra stuff in the exception frame.  */
923         if (regs->stkadj) {
924                 struct pt_regs *tregs =
925                         (struct pt_regs *)((ulong)regs + regs->stkadj);
926 #ifdef DEBUG
927                 printk("Performing stackadjust=%04x\n", regs->stkadj);
928 #endif
929                 /* This must be copied with decreasing addresses to
930                    handle overlaps.  */
931                 tregs->vector = 0;
932                 tregs->format = 0;
933                 tregs->pc = regs->pc;
934                 tregs->sr = regs->sr;
935         }
936         return 0;
937 
938 give_sigsegv:
939         force_sigsegv(sig, current);
940         return err;
941 }
942 
943 static int setup_rt_frame (int sig, struct k_sigaction *ka, siginfo_t *info,
944                             sigset_t *set, struct pt_regs *regs)
945 {
946         struct rt_sigframe __user *frame;
947         int fsize = frame_extra_sizes(regs->format);
948         int err = 0;
949 
950         if (fsize < 0) {
951 #ifdef DEBUG
952                 printk ("setup_frame: Unknown frame format %#x\n",
953                         regs->format);
954 #endif
955                 goto give_sigsegv;
956         }
957 
958         frame = get_sigframe(ka, regs, sizeof(*frame));
959 
960         if (fsize)
961                 err |= copy_to_user (&frame->uc.uc_extra, regs + 1, fsize);
962 
963         err |= __put_user((current_thread_info()->exec_domain
964                            && current_thread_info()->exec_domain->signal_invmap
965                            && sig < 32
966                            ? current_thread_info()->exec_domain->signal_invmap[sig]
967                            : sig),
968                           &frame->sig);
969         err |= __put_user(&frame->info, &frame->pinfo);
970         err |= __put_user(&frame->uc, &frame->puc);
971         err |= copy_siginfo_to_user(&frame->info, info);
972 
973         /* Create the ucontext.  */
974         err |= __put_user(0, &frame->uc.uc_flags);
975         err |= __put_user(NULL, &frame->uc.uc_link);
976         err |= __save_altstack(&frame->uc.uc_stack, rdusp());
977         err |= rt_setup_ucontext(&frame->uc, regs);
978         err |= copy_to_user (&frame->uc.uc_sigmask, set, sizeof(*set));
979 
980         /* Set up to return from userspace.  */
981 #ifdef CONFIG_MMU
982         err |= __put_user(frame->retcode, &frame->pretcode);
983 #ifdef __mcoldfire__
984         /* movel #__NR_rt_sigreturn,d0; trap #0 */
985         err |= __put_user(0x203c0000, (long __user *)(frame->retcode + 0));
986         err |= __put_user(0x00004e40 + (__NR_rt_sigreturn << 16),
987                           (long __user *)(frame->retcode + 4));
988 #else
989         /* moveq #,d0; notb d0; trap #0 */
990         err |= __put_user(0x70004600 + ((__NR_rt_sigreturn ^ 0xff) << 16),
991                           (long __user *)(frame->retcode + 0));
992         err |= __put_user(0x4e40, (short __user *)(frame->retcode + 4));
993 #endif
994 #else
995         err |= __put_user((void *) ret_from_user_rt_signal, &frame->pretcode);
996 #endif /* CONFIG_MMU */
997 
998         if (err)
999                 goto give_sigsegv;
1000 
1001         push_cache ((unsigned long) &frame->retcode);
1002 
1003         /*
1004          * Set up registers for signal handler.  All the state we are about
1005          * to destroy is successfully copied to sigframe.
1006          */
1007         wrusp ((unsigned long) frame);
1008         regs->pc = (unsigned long) ka->sa.sa_handler;
1009         adjustformat(regs);
1010 
1011         /*
1012          * This is subtle; if we build more than one sigframe, all but the
1013          * first one will see frame format 0 and have fsize == 0, so we won't
1014          * screw stkadj.
1015          */
1016         if (fsize)
1017                 regs->stkadj = fsize;
1018 
1019         /* Prepare to skip over the extra stuff in the exception frame.  */
1020         if (regs->stkadj) {
1021                 struct pt_regs *tregs =
1022                         (struct pt_regs *)((ulong)regs + regs->stkadj);
1023 #ifdef DEBUG
1024                 printk("Performing stackadjust=%04x\n", regs->stkadj);
1025 #endif
1026                 /* This must be copied with decreasing addresses to
1027                    handle overlaps.  */
1028                 tregs->vector = 0;
1029                 tregs->format = 0;
1030                 tregs->pc = regs->pc;
1031                 tregs->sr = regs->sr;
1032         }
1033         return 0;
1034 
1035 give_sigsegv:
1036         force_sigsegv(sig, current);
1037         return err;
1038 }
1039 
1040 static inline void
1041 handle_restart(struct pt_regs *regs, struct k_sigaction *ka, int has_handler)
1042 {
1043         switch (regs->d0) {
1044         case -ERESTARTNOHAND:
1045                 if (!has_handler)
1046                         goto do_restart;
1047                 regs->d0 = -EINTR;
1048                 break;
1049 
1050         case -ERESTART_RESTARTBLOCK:
1051                 if (!has_handler) {
1052                         regs->d0 = __NR_restart_syscall;
1053                         regs->pc -= 2;
1054                         break;
1055                 }
1056                 regs->d0 = -EINTR;
1057                 break;
1058 
1059         case -ERESTARTSYS:
1060                 if (has_handler && !(ka->sa.sa_flags & SA_RESTART)) {
1061                         regs->d0 = -EINTR;
1062                         break;
1063                 }
1064         /* fallthrough */
1065         case -ERESTARTNOINTR:
1066         do_restart:
1067                 regs->d0 = regs->orig_d0;
1068                 regs->pc -= 2;
1069                 break;
1070         }
1071 }
1072 
1073 /*
1074  * OK, we're invoking a handler
1075  */
1076 static void
1077 handle_signal(int sig, struct k_sigaction *ka, siginfo_t *info,
1078               struct pt_regs *regs)
1079 {
1080         sigset_t *oldset = sigmask_to_save();
1081         int err;
1082         /* are we from a system call? */
1083         if (regs->orig_d0 >= 0)
1084                 /* If so, check system call restarting.. */
1085                 handle_restart(regs, ka, 1);
1086 
1087         /* set up the stack frame */
1088         if (ka->sa.sa_flags & SA_SIGINFO)
1089                 err = setup_rt_frame(sig, ka, info, oldset, regs);
1090         else
1091                 err = setup_frame(sig, ka, oldset, regs);
1092 
1093         if (err)
1094                 return;
1095 
1096         signal_delivered(sig, info, ka, regs, 0);
1097 
1098         if (test_thread_flag(TIF_DELAYED_TRACE)) {
1099                 regs->sr &= ~0x8000;
1100                 send_sig(SIGTRAP, current, 1);
1101         }
1102 }
1103 
1104 /*
1105  * Note that 'init' is a special process: it doesn't get signals it doesn't
1106  * want to handle. Thus you cannot kill init even with a SIGKILL even by
1107  * mistake.
1108  */
1109 static void do_signal(struct pt_regs *regs)
1110 {
1111         siginfo_t info;
1112         struct k_sigaction ka;
1113         int signr;
1114 
1115         current->thread.esp0 = (unsigned long) regs;
1116 
1117         signr = get_signal_to_deliver(&info, &ka, regs, NULL);
1118         if (signr > 0) {
1119                 /* Whee!  Actually deliver the signal.  */
1120                 handle_signal(signr, &ka, &info, regs);
1121                 return;
1122         }
1123 
1124         /* Did we come from a system call? */
1125         if (regs->orig_d0 >= 0)
1126                 /* Restart the system call - no handlers present */
1127                 handle_restart(regs, NULL, 0);
1128 
1129         /* If there's no signal to deliver, we just restore the saved mask.  */
1130         restore_saved_sigmask();
1131 }
1132 
1133 void do_notify_resume(struct pt_regs *regs)
1134 {
1135         if (test_thread_flag(TIF_SIGPENDING))
1136                 do_signal(regs);
1137 
1138         if (test_and_clear_thread_flag(TIF_NOTIFY_RESUME))
1139                 tracehook_notify_resume(regs);
1140 }
1141 

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