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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/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                                       : "" (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         /*
580          * This needs to be tested on m68k as it has a lesser
581          * alignment requirement than x86 and that can cause surprises.
582          */
583 
584         /* This is part of the ABI and can never change in size: */
585         BUILD_BUG_ON(sizeof(siginfo_t) != 128);
586 
587         /* Ensure the known fields never change in location */
588         BUILD_BUG_ON(offsetof(siginfo_t, si_signo) != 0);
589         BUILD_BUG_ON(offsetof(siginfo_t, si_errno) != 4);
590         BUILD_BUG_ON(offsetof(siginfo_t, si_code)  != 8);
591 
592         /* _kill */
593         BUILD_BUG_ON(offsetof(siginfo_t, si_pid) != 0x0c);
594         BUILD_BUG_ON(offsetof(siginfo_t, si_uid) != 0x10);
595 
596         /* _timer */
597         BUILD_BUG_ON(offsetof(siginfo_t, si_tid)     != 0x0c);
598         BUILD_BUG_ON(offsetof(siginfo_t, si_overrun) != 0x10);
599         BUILD_BUG_ON(offsetof(siginfo_t, si_value)   != 0x14);
600 
601         /* _rt */
602         BUILD_BUG_ON(offsetof(siginfo_t, si_pid)   != 0x0c);
603         BUILD_BUG_ON(offsetof(siginfo_t, si_uid)   != 0x10);
604         BUILD_BUG_ON(offsetof(siginfo_t, si_value) != 0x14);
605 
606         /* _sigchld */
607         BUILD_BUG_ON(offsetof(siginfo_t, si_pid)    != 0x0c);
608         BUILD_BUG_ON(offsetof(siginfo_t, si_uid)    != 0x10);
609         BUILD_BUG_ON(offsetof(siginfo_t, si_status) != 0x14);
610         BUILD_BUG_ON(offsetof(siginfo_t, si_utime)  != 0x18);
611         BUILD_BUG_ON(offsetof(siginfo_t, si_stime)  != 0x1c);
612 
613         /* _sigfault */
614         BUILD_BUG_ON(offsetof(siginfo_t, si_addr) != 0x0c);
615 
616         /* _sigfault._mcerr */
617         BUILD_BUG_ON(offsetof(siginfo_t, si_addr_lsb) != 0x10);
618 
619         /* _sigfault._addr_bnd */
620         BUILD_BUG_ON(offsetof(siginfo_t, si_lower) != 0x12);
621         BUILD_BUG_ON(offsetof(siginfo_t, si_upper) != 0x16);
622 
623         /* _sigfault._addr_pkey */
624         BUILD_BUG_ON(offsetof(siginfo_t, si_pkey) != 0x12);
625 
626         /* _sigpoll */
627         BUILD_BUG_ON(offsetof(siginfo_t, si_band)   != 0x0c);
628         BUILD_BUG_ON(offsetof(siginfo_t, si_fd)     != 0x10);
629 
630         /* _sigsys */
631         BUILD_BUG_ON(offsetof(siginfo_t, si_call_addr) != 0x0c);
632         BUILD_BUG_ON(offsetof(siginfo_t, si_syscall)   != 0x10);
633         BUILD_BUG_ON(offsetof(siginfo_t, si_arch)      != 0x14);
634 
635         /* any new si_fields should be added here */
636 }
637 
638 static int mangle_kernel_stack(struct pt_regs *regs, int formatvec,
639                                void __user *fp)
640 {
641         int fsize = frame_extra_sizes(formatvec >> 12);
642         if (fsize < 0) {
643                 /*
644                  * user process trying to return with weird frame format
645                  */
646                 pr_debug("user process returning with weird frame format\n");
647                 return 1;
648         }
649         if (!fsize) {
650                 regs->format = formatvec >> 12;
651                 regs->vector = formatvec & 0xfff;
652         } else {
653                 struct switch_stack *sw = (struct switch_stack *)regs - 1;
654                 /* yes, twice as much as max(sizeof(frame.un.fmt<x>)) */
655                 unsigned long buf[sizeof(((struct frame *)0)->un) / 2];
656 
657                 /* that'll make sure that expansion won't crap over data */
658                 if (copy_from_user(buf + fsize / 4, fp, fsize))
659                         return 1;
660 
661                 /* point of no return */
662                 regs->format = formatvec >> 12;
663                 regs->vector = formatvec & 0xfff;
664 #define frame_offset (sizeof(struct pt_regs)+sizeof(struct switch_stack))
665                 __asm__ __volatile__ (
666 #ifdef CONFIG_COLDFIRE
667                          "   movel %0,%/sp\n\t"
668                          "   bra ret_from_signal\n"
669 #else
670                          "   movel %0,%/a0\n\t"
671                          "   subl %1,%/a0\n\t"     /* make room on stack */
672                          "   movel %/a0,%/sp\n\t"  /* set stack pointer */
673                          /* move switch_stack and pt_regs */
674                          "1: movel %0@+,%/a0@+\n\t"
675                          "   dbra %2,1b\n\t"
676                          "   lea %/sp@(%c3),%/a0\n\t" /* add offset of fmt */
677                          "   lsrl  #2,%1\n\t"
678                          "   subql #1,%1\n\t"
679                          /* copy to the gap we'd made */
680                          "2: movel %4@+,%/a0@+\n\t"
681                          "   dbra %1,2b\n\t"
682                          "   bral ret_from_signal\n"
683 #endif
684                          : /* no outputs, it doesn't ever return */
685                          : "a" (sw), "d" (fsize), "d" (frame_offset/4-1),
686                            "n" (frame_offset), "a" (buf + fsize/4)
687                          : "a0");
688 #undef frame_offset
689         }
690         return 0;
691 }
692 
693 static inline int
694 restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *usc, void __user *fp)
695 {
696         int formatvec;
697         struct sigcontext context;
698         int err = 0;
699 
700         siginfo_build_tests();
701 
702         /* Always make any pending restarted system calls return -EINTR */
703         current->restart_block.fn = do_no_restart_syscall;
704 
705         /* get previous context */
706         if (copy_from_user(&context, usc, sizeof(context)))
707                 goto badframe;
708 
709         /* restore passed registers */
710         regs->d0 = context.sc_d0;
711         regs->d1 = context.sc_d1;
712         regs->a0 = context.sc_a0;
713         regs->a1 = context.sc_a1;
714         regs->sr = (regs->sr & 0xff00) | (context.sc_sr & 0xff);
715         regs->pc = context.sc_pc;
716         regs->orig_d0 = -1;             /* disable syscall checks */
717         wrusp(context.sc_usp);
718         formatvec = context.sc_formatvec;
719 
720         err = restore_fpu_state(&context);
721 
722         if (err || mangle_kernel_stack(regs, formatvec, fp))
723                 goto badframe;
724 
725         return 0;
726 
727 badframe:
728         return 1;
729 }
730 
731 static inline int
732 rt_restore_ucontext(struct pt_regs *regs, struct switch_stack *sw,
733                     struct ucontext __user *uc)
734 {
735         int temp;
736         greg_t __user *gregs = uc->uc_mcontext.gregs;
737         unsigned long usp;
738         int err;
739 
740         /* Always make any pending restarted system calls return -EINTR */
741         current->restart_block.fn = do_no_restart_syscall;
742 
743         err = __get_user(temp, &uc->uc_mcontext.version);
744         if (temp != MCONTEXT_VERSION)
745                 goto badframe;
746         /* restore passed registers */
747         err |= __get_user(regs->d0, &gregs[0]);
748         err |= __get_user(regs->d1, &gregs[1]);
749         err |= __get_user(regs->d2, &gregs[2]);
750         err |= __get_user(regs->d3, &gregs[3]);
751         err |= __get_user(regs->d4, &gregs[4]);
752         err |= __get_user(regs->d5, &gregs[5]);
753         err |= __get_user(sw->d6, &gregs[6]);
754         err |= __get_user(sw->d7, &gregs[7]);
755         err |= __get_user(regs->a0, &gregs[8]);
756         err |= __get_user(regs->a1, &gregs[9]);
757         err |= __get_user(regs->a2, &gregs[10]);
758         err |= __get_user(sw->a3, &gregs[11]);
759         err |= __get_user(sw->a4, &gregs[12]);
760         err |= __get_user(sw->a5, &gregs[13]);
761         err |= __get_user(sw->a6, &gregs[14]);
762         err |= __get_user(usp, &gregs[15]);
763         wrusp(usp);
764         err |= __get_user(regs->pc, &gregs[16]);
765         err |= __get_user(temp, &gregs[17]);
766         regs->sr = (regs->sr & 0xff00) | (temp & 0xff);
767         regs->orig_d0 = -1;             /* disable syscall checks */
768         err |= __get_user(temp, &uc->uc_formatvec);
769 
770         err |= rt_restore_fpu_state(uc);
771         err |= restore_altstack(&uc->uc_stack);
772 
773         if (err)
774                 goto badframe;
775 
776         if (mangle_kernel_stack(regs, temp, &uc->uc_extra))
777                 goto badframe;
778 
779         return 0;
780 
781 badframe:
782         return 1;
783 }
784 
785 asmlinkage int do_sigreturn(struct pt_regs *regs, struct switch_stack *sw)
786 {
787         unsigned long usp = rdusp();
788         struct sigframe __user *frame = (struct sigframe __user *)(usp - 4);
789         sigset_t set;
790 
791         if (!access_ok(frame, sizeof(*frame)))
792                 goto badframe;
793         if (__get_user(set.sig[0], &frame->sc.sc_mask) ||
794             (_NSIG_WORDS > 1 &&
795              __copy_from_user(&set.sig[1], &frame->extramask,
796                               sizeof(frame->extramask))))
797                 goto badframe;
798 
799         set_current_blocked(&set);
800 
801         if (restore_sigcontext(regs, &frame->sc, frame + 1))
802                 goto badframe;
803         return regs->d0;
804 
805 badframe:
806         force_sig(SIGSEGV);
807         return 0;
808 }
809 
810 asmlinkage int do_rt_sigreturn(struct pt_regs *regs, struct switch_stack *sw)
811 {
812         unsigned long usp = rdusp();
813         struct rt_sigframe __user *frame = (struct rt_sigframe __user *)(usp - 4);
814         sigset_t set;
815 
816         if (!access_ok(frame, sizeof(*frame)))
817                 goto badframe;
818         if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set)))
819                 goto badframe;
820 
821         set_current_blocked(&set);
822 
823         if (rt_restore_ucontext(regs, sw, &frame->uc))
824                 goto badframe;
825         return regs->d0;
826 
827 badframe:
828         force_sig(SIGSEGV);
829         return 0;
830 }
831 
832 static void setup_sigcontext(struct sigcontext *sc, struct pt_regs *regs,
833                              unsigned long mask)
834 {
835         sc->sc_mask = mask;
836         sc->sc_usp = rdusp();
837         sc->sc_d0 = regs->d0;
838         sc->sc_d1 = regs->d1;
839         sc->sc_a0 = regs->a0;
840         sc->sc_a1 = regs->a1;
841         sc->sc_sr = regs->sr;
842         sc->sc_pc = regs->pc;
843         sc->sc_formatvec = regs->format << 12 | regs->vector;
844         save_a5_state(sc, regs);
845         save_fpu_state(sc, regs);
846 }
847 
848 static inline int rt_setup_ucontext(struct ucontext __user *uc, struct pt_regs *regs)
849 {
850         struct switch_stack *sw = (struct switch_stack *)regs - 1;
851         greg_t __user *gregs = uc->uc_mcontext.gregs;
852         int err = 0;
853 
854         err |= __put_user(MCONTEXT_VERSION, &uc->uc_mcontext.version);
855         err |= __put_user(regs->d0, &gregs[0]);
856         err |= __put_user(regs->d1, &gregs[1]);
857         err |= __put_user(regs->d2, &gregs[2]);
858         err |= __put_user(regs->d3, &gregs[3]);
859         err |= __put_user(regs->d4, &gregs[4]);
860         err |= __put_user(regs->d5, &gregs[5]);
861         err |= __put_user(sw->d6, &gregs[6]);
862         err |= __put_user(sw->d7, &gregs[7]);
863         err |= __put_user(regs->a0, &gregs[8]);
864         err |= __put_user(regs->a1, &gregs[9]);
865         err |= __put_user(regs->a2, &gregs[10]);
866         err |= __put_user(sw->a3, &gregs[11]);
867         err |= __put_user(sw->a4, &gregs[12]);
868         err |= __put_user(sw->a5, &gregs[13]);
869         err |= __put_user(sw->a6, &gregs[14]);
870         err |= __put_user(rdusp(), &gregs[15]);
871         err |= __put_user(regs->pc, &gregs[16]);
872         err |= __put_user(regs->sr, &gregs[17]);
873         err |= __put_user((regs->format << 12) | regs->vector, &uc->uc_formatvec);
874         err |= rt_save_fpu_state(uc, regs);
875         return err;
876 }
877 
878 static inline void __user *
879 get_sigframe(struct ksignal *ksig, size_t frame_size)
880 {
881         unsigned long usp = sigsp(rdusp(), ksig);
882 
883         return (void __user *)((usp - frame_size) & -8UL);
884 }
885 
886 static int setup_frame(struct ksignal *ksig, sigset_t *set,
887                         struct pt_regs *regs)
888 {
889         struct sigframe __user *frame;
890         int fsize = frame_extra_sizes(regs->format);
891         struct sigcontext context;
892         int err = 0, sig = ksig->sig;
893 
894         if (fsize < 0) {
895                 pr_debug("setup_frame: Unknown frame format %#x\n",
896                          regs->format);
897                 return -EFAULT;
898         }
899 
900         frame = get_sigframe(ksig, sizeof(*frame) + fsize);
901 
902         if (fsize)
903                 err |= copy_to_user (frame + 1, regs + 1, fsize);
904 
905         err |= __put_user(sig, &frame->sig);
906 
907         err |= __put_user(regs->vector, &frame->code);
908         err |= __put_user(&frame->sc, &frame->psc);
909 
910         if (_NSIG_WORDS > 1)
911                 err |= copy_to_user(frame->extramask, &set->sig[1],
912                                     sizeof(frame->extramask));
913 
914         setup_sigcontext(&context, regs, set->sig[0]);
915         err |= copy_to_user (&frame->sc, &context, sizeof(context));
916 
917         /* Set up to return from userspace.  */
918 #ifdef CONFIG_MMU
919         err |= __put_user(frame->retcode, &frame->pretcode);
920         /* moveq #,d0; trap #0 */
921         err |= __put_user(0x70004e40 + (__NR_sigreturn << 16),
922                           (long __user *)(frame->retcode));
923 #else
924         err |= __put_user((void *) ret_from_user_signal, &frame->pretcode);
925 #endif
926 
927         if (err)
928                 return -EFAULT;
929 
930         push_cache ((unsigned long) &frame->retcode);
931 
932         /*
933          * Set up registers for signal handler.  All the state we are about
934          * to destroy is successfully copied to sigframe.
935          */
936         wrusp ((unsigned long) frame);
937         regs->pc = (unsigned long) ksig->ka.sa.sa_handler;
938         adjustformat(regs);
939 
940         /*
941          * This is subtle; if we build more than one sigframe, all but the
942          * first one will see frame format 0 and have fsize == 0, so we won't
943          * screw stkadj.
944          */
945         if (fsize)
946                 regs->stkadj = fsize;
947 
948         /* Prepare to skip over the extra stuff in the exception frame.  */
949         if (regs->stkadj) {
950                 struct pt_regs *tregs =
951                         (struct pt_regs *)((ulong)regs + regs->stkadj);
952                 pr_debug("Performing stackadjust=%04lx\n", regs->stkadj);
953                 /* This must be copied with decreasing addresses to
954                    handle overlaps.  */
955                 tregs->vector = 0;
956                 tregs->format = 0;
957                 tregs->pc = regs->pc;
958                 tregs->sr = regs->sr;
959         }
960         return 0;
961 }
962 
963 static int setup_rt_frame(struct ksignal *ksig, sigset_t *set,
964                            struct pt_regs *regs)
965 {
966         struct rt_sigframe __user *frame;
967         int fsize = frame_extra_sizes(regs->format);
968         int err = 0, sig = ksig->sig;
969 
970         if (fsize < 0) {
971                 pr_debug("setup_frame: Unknown frame format %#x\n",
972                          regs->format);
973                 return -EFAULT;
974         }
975 
976         frame = get_sigframe(ksig, sizeof(*frame));
977 
978         if (fsize)
979                 err |= copy_to_user (&frame->uc.uc_extra, regs + 1, fsize);
980 
981         err |= __put_user(sig, &frame->sig);
982         err |= __put_user(&frame->info, &frame->pinfo);
983         err |= __put_user(&frame->uc, &frame->puc);
984         err |= copy_siginfo_to_user(&frame->info, &ksig->info);
985 
986         /* Create the ucontext.  */
987         err |= __put_user(0, &frame->uc.uc_flags);
988         err |= __put_user(NULL, &frame->uc.uc_link);
989         err |= __save_altstack(&frame->uc.uc_stack, rdusp());
990         err |= rt_setup_ucontext(&frame->uc, regs);
991         err |= copy_to_user (&frame->uc.uc_sigmask, set, sizeof(*set));
992 
993         /* Set up to return from userspace.  */
994 #ifdef CONFIG_MMU
995         err |= __put_user(frame->retcode, &frame->pretcode);
996 #ifdef __mcoldfire__
997         /* movel #__NR_rt_sigreturn,d0; trap #0 */
998         err |= __put_user(0x203c0000, (long __user *)(frame->retcode + 0));
999         err |= __put_user(0x00004e40 + (__NR_rt_sigreturn << 16),
1000                           (long __user *)(frame->retcode + 4));
1001 #else
1002         /* moveq #,d0; notb d0; trap #0 */
1003         err |= __put_user(0x70004600 + ((__NR_rt_sigreturn ^ 0xff) << 16),
1004                           (long __user *)(frame->retcode + 0));
1005         err |= __put_user(0x4e40, (short __user *)(frame->retcode + 4));
1006 #endif
1007 #else
1008         err |= __put_user((void *) ret_from_user_rt_signal, &frame->pretcode);
1009 #endif /* CONFIG_MMU */
1010 
1011         if (err)
1012                 return -EFAULT;
1013 
1014         push_cache ((unsigned long) &frame->retcode);
1015 
1016         /*
1017          * Set up registers for signal handler.  All the state we are about
1018          * to destroy is successfully copied to sigframe.
1019          */
1020         wrusp ((unsigned long) frame);
1021         regs->pc = (unsigned long) ksig->ka.sa.sa_handler;
1022         adjustformat(regs);
1023 
1024         /*
1025          * This is subtle; if we build more than one sigframe, all but the
1026          * first one will see frame format 0 and have fsize == 0, so we won't
1027          * screw stkadj.
1028          */
1029         if (fsize)
1030                 regs->stkadj = fsize;
1031 
1032         /* Prepare to skip over the extra stuff in the exception frame.  */
1033         if (regs->stkadj) {
1034                 struct pt_regs *tregs =
1035                         (struct pt_regs *)((ulong)regs + regs->stkadj);
1036                 pr_debug("Performing stackadjust=%04lx\n", regs->stkadj);
1037                 /* This must be copied with decreasing addresses to
1038                    handle overlaps.  */
1039                 tregs->vector = 0;
1040                 tregs->format = 0;
1041                 tregs->pc = regs->pc;
1042                 tregs->sr = regs->sr;
1043         }
1044         return 0;
1045 }
1046 
1047 static inline void
1048 handle_restart(struct pt_regs *regs, struct k_sigaction *ka, int has_handler)
1049 {
1050         switch (regs->d0) {
1051         case -ERESTARTNOHAND:
1052                 if (!has_handler)
1053                         goto do_restart;
1054                 regs->d0 = -EINTR;
1055                 break;
1056 
1057         case -ERESTART_RESTARTBLOCK:
1058                 if (!has_handler) {
1059                         regs->d0 = __NR_restart_syscall;
1060                         regs->pc -= 2;
1061                         break;
1062                 }
1063                 regs->d0 = -EINTR;
1064                 break;
1065 
1066         case -ERESTARTSYS:
1067                 if (has_handler && !(ka->sa.sa_flags & SA_RESTART)) {
1068                         regs->d0 = -EINTR;
1069                         break;
1070                 }
1071         /* fallthrough */
1072         case -ERESTARTNOINTR:
1073         do_restart:
1074                 regs->d0 = regs->orig_d0;
1075                 regs->pc -= 2;
1076                 break;
1077         }
1078 }
1079 
1080 /*
1081  * OK, we're invoking a handler
1082  */
1083 static void
1084 handle_signal(struct ksignal *ksig, struct pt_regs *regs)
1085 {
1086         sigset_t *oldset = sigmask_to_save();
1087         int err;
1088         /* are we from a system call? */
1089         if (regs->orig_d0 >= 0)
1090                 /* If so, check system call restarting.. */
1091                 handle_restart(regs, &ksig->ka, 1);
1092 
1093         /* set up the stack frame */
1094         if (ksig->ka.sa.sa_flags & SA_SIGINFO)
1095                 err = setup_rt_frame(ksig, oldset, regs);
1096         else
1097                 err = setup_frame(ksig, oldset, regs);
1098 
1099         signal_setup_done(err, ksig, 0);
1100 
1101         if (test_thread_flag(TIF_DELAYED_TRACE)) {
1102                 regs->sr &= ~0x8000;
1103                 send_sig(SIGTRAP, current, 1);
1104         }
1105 }
1106 
1107 /*
1108  * Note that 'init' is a special process: it doesn't get signals it doesn't
1109  * want to handle. Thus you cannot kill init even with a SIGKILL even by
1110  * mistake.
1111  */
1112 static void do_signal(struct pt_regs *regs)
1113 {
1114         struct ksignal ksig;
1115 
1116         current->thread.esp0 = (unsigned long) regs;
1117 
1118         if (get_signal(&ksig)) {
1119                 /* Whee!  Actually deliver the signal.  */
1120                 handle_signal(&ksig, 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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