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new helper: restore_saved_sigmask()
[deliverable/linux.git] / arch / m68k / kernel / signal.c
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
54 #define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP)))
55
56 #ifdef CONFIG_MMU
57
58 /*
59 * Handle the slight differences in classic 68k and ColdFire trap frames.
60 */
61 #ifdef CONFIG_COLDFIRE
62 #define FORMAT 4
63 #define FMT4SIZE 0
64 #else
65 #define FORMAT 0
66 #define FMT4SIZE sizeof(((struct frame *)0)->un.fmt4)
67 #endif
68
69 static const int frame_size_change[16] = {
70 [1] = -1, /* sizeof(((struct frame *)0)->un.fmt1), */
71 [2] = sizeof(((struct frame *)0)->un.fmt2),
72 [3] = sizeof(((struct frame *)0)->un.fmt3),
73 [4] = FMT4SIZE,
74 [5] = -1, /* sizeof(((struct frame *)0)->un.fmt5), */
75 [6] = -1, /* sizeof(((struct frame *)0)->un.fmt6), */
76 [7] = sizeof(((struct frame *)0)->un.fmt7),
77 [8] = -1, /* sizeof(((struct frame *)0)->un.fmt8), */
78 [9] = sizeof(((struct frame *)0)->un.fmt9),
79 [10] = sizeof(((struct frame *)0)->un.fmta),
80 [11] = sizeof(((struct frame *)0)->un.fmtb),
81 [12] = -1, /* sizeof(((struct frame *)0)->un.fmtc), */
82 [13] = -1, /* sizeof(((struct frame *)0)->un.fmtd), */
83 [14] = -1, /* sizeof(((struct frame *)0)->un.fmte), */
84 [15] = -1, /* sizeof(((struct frame *)0)->un.fmtf), */
85 };
86
87 static inline int frame_extra_sizes(int f)
88 {
89 return frame_size_change[f];
90 }
91
92 int handle_kernel_fault(struct pt_regs *regs)
93 {
94 const struct exception_table_entry *fixup;
95 struct pt_regs *tregs;
96
97 /* Are we prepared to handle this kernel fault? */
98 fixup = search_exception_tables(regs->pc);
99 if (!fixup)
100 return 0;
101
102 /* Create a new four word stack frame, discarding the old one. */
103 regs->stkadj = frame_extra_sizes(regs->format);
104 tregs = (struct pt_regs *)((long)regs + regs->stkadj);
105 tregs->vector = regs->vector;
106 tregs->format = FORMAT;
107 tregs->pc = fixup->fixup;
108 tregs->sr = regs->sr;
109
110 return 1;
111 }
112
113 void ptrace_signal_deliver(struct pt_regs *regs, void *cookie)
114 {
115 if (regs->orig_d0 < 0)
116 return;
117 switch (regs->d0) {
118 case -ERESTARTNOHAND:
119 case -ERESTARTSYS:
120 case -ERESTARTNOINTR:
121 regs->d0 = regs->orig_d0;
122 regs->orig_d0 = -1;
123 regs->pc -= 2;
124 break;
125 }
126 }
127
128 static inline void push_cache (unsigned long vaddr)
129 {
130 /*
131 * Using the old cache_push_v() was really a big waste.
132 *
133 * What we are trying to do is to flush 8 bytes to ram.
134 * Flushing 2 cache lines of 16 bytes is much cheaper than
135 * flushing 1 or 2 pages, as previously done in
136 * cache_push_v().
137 * Jes
138 */
139 if (CPU_IS_040) {
140 unsigned long temp;
141
142 __asm__ __volatile__ (".chip 68040\n\t"
143 "nop\n\t"
144 "ptestr (%1)\n\t"
145 "movec %%mmusr,%0\n\t"
146 ".chip 68k"
147 : "=r" (temp)
148 : "a" (vaddr));
149
150 temp &= PAGE_MASK;
151 temp |= vaddr & ~PAGE_MASK;
152
153 __asm__ __volatile__ (".chip 68040\n\t"
154 "nop\n\t"
155 "cpushl %%bc,(%0)\n\t"
156 ".chip 68k"
157 : : "a" (temp));
158 }
159 else if (CPU_IS_060) {
160 unsigned long temp;
161 __asm__ __volatile__ (".chip 68060\n\t"
162 "plpar (%0)\n\t"
163 ".chip 68k"
164 : "=a" (temp)
165 : "0" (vaddr));
166 __asm__ __volatile__ (".chip 68060\n\t"
167 "cpushl %%bc,(%0)\n\t"
168 ".chip 68k"
169 : : "a" (temp));
170 } else if (!CPU_IS_COLDFIRE) {
171 /*
172 * 68030/68020 have no writeback cache;
173 * still need to clear icache.
174 * Note that vaddr is guaranteed to be long word aligned.
175 */
176 unsigned long temp;
177 asm volatile ("movec %%cacr,%0" : "=r" (temp));
178 temp += 4;
179 asm volatile ("movec %0,%%caar\n\t"
180 "movec %1,%%cacr"
181 : : "r" (vaddr), "r" (temp));
182 asm volatile ("movec %0,%%caar\n\t"
183 "movec %1,%%cacr"
184 : : "r" (vaddr + 4), "r" (temp));
185 }
186 }
187
188 static inline void adjustformat(struct pt_regs *regs)
189 {
190 }
191
192 static inline void save_a5_state(struct sigcontext *sc, struct pt_regs *regs)
193 {
194 }
195
196 #else /* CONFIG_MMU */
197
198 void ret_from_user_signal(void);
199 void ret_from_user_rt_signal(void);
200
201 static inline int frame_extra_sizes(int f)
202 {
203 /* No frame size adjustments required on non-MMU CPUs */
204 return 0;
205 }
206
207 static inline void adjustformat(struct pt_regs *regs)
208 {
209 ((struct switch_stack *)regs - 1)->a5 = current->mm->start_data;
210 /*
211 * set format byte to make stack appear modulo 4, which it will
212 * be when doing the rte
213 */
214 regs->format = 0x4;
215 }
216
217 static inline void save_a5_state(struct sigcontext *sc, struct pt_regs *regs)
218 {
219 sc->sc_a5 = ((struct switch_stack *)regs - 1)->a5;
220 }
221
222 static inline void push_cache(unsigned long vaddr)
223 {
224 }
225
226 #endif /* CONFIG_MMU */
227
228 /*
229 * Atomically swap in the new signal mask, and wait for a signal.
230 */
231 asmlinkage int
232 sys_sigsuspend(int unused0, int unused1, old_sigset_t mask)
233 {
234 sigset_t blocked;
235 siginitset(&blocked, mask);
236 return sigsuspend(&blocked);
237 }
238
239 asmlinkage int
240 sys_sigaction(int sig, const struct old_sigaction __user *act,
241 struct old_sigaction __user *oact)
242 {
243 struct k_sigaction new_ka, old_ka;
244 int ret;
245
246 if (act) {
247 old_sigset_t mask;
248 if (!access_ok(VERIFY_READ, act, sizeof(*act)) ||
249 __get_user(new_ka.sa.sa_handler, &act->sa_handler) ||
250 __get_user(new_ka.sa.sa_restorer, &act->sa_restorer) ||
251 __get_user(new_ka.sa.sa_flags, &act->sa_flags) ||
252 __get_user(mask, &act->sa_mask))
253 return -EFAULT;
254 siginitset(&new_ka.sa.sa_mask, mask);
255 }
256
257 ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL);
258
259 if (!ret && oact) {
260 if (!access_ok(VERIFY_WRITE, oact, sizeof(*oact)) ||
261 __put_user(old_ka.sa.sa_handler, &oact->sa_handler) ||
262 __put_user(old_ka.sa.sa_restorer, &oact->sa_restorer) ||
263 __put_user(old_ka.sa.sa_flags, &oact->sa_flags) ||
264 __put_user(old_ka.sa.sa_mask.sig[0], &oact->sa_mask))
265 return -EFAULT;
266 }
267
268 return ret;
269 }
270
271 asmlinkage int
272 sys_sigaltstack(const stack_t __user *uss, stack_t __user *uoss)
273 {
274 return do_sigaltstack(uss, uoss, rdusp());
275 }
276
277
278 /*
279 * Do a signal return; undo the signal stack.
280 *
281 * Keep the return code on the stack quadword aligned!
282 * That makes the cache flush below easier.
283 */
284
285 struct sigframe
286 {
287 char __user *pretcode;
288 int sig;
289 int code;
290 struct sigcontext __user *psc;
291 char retcode[8];
292 unsigned long extramask[_NSIG_WORDS-1];
293 struct sigcontext sc;
294 };
295
296 struct rt_sigframe
297 {
298 char __user *pretcode;
299 int sig;
300 struct siginfo __user *pinfo;
301 void __user *puc;
302 char retcode[8];
303 struct siginfo info;
304 struct ucontext uc;
305 };
306
307 #define FPCONTEXT_SIZE 216
308 #define uc_fpstate uc_filler[0]
309 #define uc_formatvec uc_filler[FPCONTEXT_SIZE/4]
310 #define uc_extra uc_filler[FPCONTEXT_SIZE/4+1]
311
312 #ifdef CONFIG_FPU
313
314 static unsigned char fpu_version; /* version number of fpu, set by setup_frame */
315
316 static inline int restore_fpu_state(struct sigcontext *sc)
317 {
318 int err = 1;
319
320 if (FPU_IS_EMU) {
321 /* restore registers */
322 memcpy(current->thread.fpcntl, sc->sc_fpcntl, 12);
323 memcpy(current->thread.fp, sc->sc_fpregs, 24);
324 return 0;
325 }
326
327 if (CPU_IS_060 ? sc->sc_fpstate[2] : sc->sc_fpstate[0]) {
328 /* Verify the frame format. */
329 if (!(CPU_IS_060 || CPU_IS_COLDFIRE) &&
330 (sc->sc_fpstate[0] != fpu_version))
331 goto out;
332 if (CPU_IS_020_OR_030) {
333 if (m68k_fputype & FPU_68881 &&
334 !(sc->sc_fpstate[1] == 0x18 || sc->sc_fpstate[1] == 0xb4))
335 goto out;
336 if (m68k_fputype & FPU_68882 &&
337 !(sc->sc_fpstate[1] == 0x38 || sc->sc_fpstate[1] == 0xd4))
338 goto out;
339 } else if (CPU_IS_040) {
340 if (!(sc->sc_fpstate[1] == 0x00 ||
341 sc->sc_fpstate[1] == 0x28 ||
342 sc->sc_fpstate[1] == 0x60))
343 goto out;
344 } else if (CPU_IS_060) {
345 if (!(sc->sc_fpstate[3] == 0x00 ||
346 sc->sc_fpstate[3] == 0x60 ||
347 sc->sc_fpstate[3] == 0xe0))
348 goto out;
349 } else if (CPU_IS_COLDFIRE) {
350 if (!(sc->sc_fpstate[0] == 0x00 ||
351 sc->sc_fpstate[0] == 0x05 ||
352 sc->sc_fpstate[0] == 0xe5))
353 goto out;
354 } else
355 goto out;
356
357 if (CPU_IS_COLDFIRE) {
358 __asm__ volatile ("fmovemd %0,%%fp0-%%fp1\n\t"
359 "fmovel %1,%%fpcr\n\t"
360 "fmovel %2,%%fpsr\n\t"
361 "fmovel %3,%%fpiar"
362 : /* no outputs */
363 : "m" (sc->sc_fpregs[0]),
364 "m" (sc->sc_fpcntl[0]),
365 "m" (sc->sc_fpcntl[1]),
366 "m" (sc->sc_fpcntl[2]));
367 } else {
368 __asm__ volatile (".chip 68k/68881\n\t"
369 "fmovemx %0,%%fp0-%%fp1\n\t"
370 "fmoveml %1,%%fpcr/%%fpsr/%%fpiar\n\t"
371 ".chip 68k"
372 : /* no outputs */
373 : "m" (*sc->sc_fpregs),
374 "m" (*sc->sc_fpcntl));
375 }
376 }
377
378 if (CPU_IS_COLDFIRE) {
379 __asm__ volatile ("frestore %0" : : "m" (*sc->sc_fpstate));
380 } else {
381 __asm__ volatile (".chip 68k/68881\n\t"
382 "frestore %0\n\t"
383 ".chip 68k"
384 : : "m" (*sc->sc_fpstate));
385 }
386 err = 0;
387
388 out:
389 return err;
390 }
391
392 static inline int rt_restore_fpu_state(struct ucontext __user *uc)
393 {
394 unsigned char fpstate[FPCONTEXT_SIZE];
395 int context_size = CPU_IS_060 ? 8 : (CPU_IS_COLDFIRE ? 12 : 0);
396 fpregset_t fpregs;
397 int err = 1;
398
399 if (FPU_IS_EMU) {
400 /* restore fpu control register */
401 if (__copy_from_user(current->thread.fpcntl,
402 uc->uc_mcontext.fpregs.f_fpcntl, 12))
403 goto out;
404 /* restore all other fpu register */
405 if (__copy_from_user(current->thread.fp,
406 uc->uc_mcontext.fpregs.f_fpregs, 96))
407 goto out;
408 return 0;
409 }
410
411 if (__get_user(*(long *)fpstate, (long __user *)&uc->uc_fpstate))
412 goto out;
413 if (CPU_IS_060 ? fpstate[2] : fpstate[0]) {
414 if (!(CPU_IS_060 || CPU_IS_COLDFIRE))
415 context_size = fpstate[1];
416 /* Verify the frame format. */
417 if (!(CPU_IS_060 || CPU_IS_COLDFIRE) &&
418 (fpstate[0] != fpu_version))
419 goto out;
420 if (CPU_IS_020_OR_030) {
421 if (m68k_fputype & FPU_68881 &&
422 !(context_size == 0x18 || context_size == 0xb4))
423 goto out;
424 if (m68k_fputype & FPU_68882 &&
425 !(context_size == 0x38 || context_size == 0xd4))
426 goto out;
427 } else if (CPU_IS_040) {
428 if (!(context_size == 0x00 ||
429 context_size == 0x28 ||
430 context_size == 0x60))
431 goto out;
432 } else if (CPU_IS_060) {
433 if (!(fpstate[3] == 0x00 ||
434 fpstate[3] == 0x60 ||
435 fpstate[3] == 0xe0))
436 goto out;
437 } else if (CPU_IS_COLDFIRE) {
438 if (!(fpstate[3] == 0x00 ||
439 fpstate[3] == 0x05 ||
440 fpstate[3] == 0xe5))
441 goto out;
442 } else
443 goto out;
444 if (__copy_from_user(&fpregs, &uc->uc_mcontext.fpregs,
445 sizeof(fpregs)))
446 goto out;
447
448 if (CPU_IS_COLDFIRE) {
449 __asm__ volatile ("fmovemd %0,%%fp0-%%fp7\n\t"
450 "fmovel %1,%%fpcr\n\t"
451 "fmovel %2,%%fpsr\n\t"
452 "fmovel %3,%%fpiar"
453 : /* no outputs */
454 : "m" (fpregs.f_fpregs[0]),
455 "m" (fpregs.f_fpcntl[0]),
456 "m" (fpregs.f_fpcntl[1]),
457 "m" (fpregs.f_fpcntl[2]));
458 } else {
459 __asm__ volatile (".chip 68k/68881\n\t"
460 "fmovemx %0,%%fp0-%%fp7\n\t"
461 "fmoveml %1,%%fpcr/%%fpsr/%%fpiar\n\t"
462 ".chip 68k"
463 : /* no outputs */
464 : "m" (*fpregs.f_fpregs),
465 "m" (*fpregs.f_fpcntl));
466 }
467 }
468 if (context_size &&
469 __copy_from_user(fpstate + 4, (long __user *)&uc->uc_fpstate + 1,
470 context_size))
471 goto out;
472
473 if (CPU_IS_COLDFIRE) {
474 __asm__ volatile ("frestore %0" : : "m" (*fpstate));
475 } else {
476 __asm__ volatile (".chip 68k/68881\n\t"
477 "frestore %0\n\t"
478 ".chip 68k"
479 : : "m" (*fpstate));
480 }
481 err = 0;
482
483 out:
484 return err;
485 }
486
487 /*
488 * Set up a signal frame.
489 */
490 static inline void save_fpu_state(struct sigcontext *sc, struct pt_regs *regs)
491 {
492 if (FPU_IS_EMU) {
493 /* save registers */
494 memcpy(sc->sc_fpcntl, current->thread.fpcntl, 12);
495 memcpy(sc->sc_fpregs, current->thread.fp, 24);
496 return;
497 }
498
499 if (CPU_IS_COLDFIRE) {
500 __asm__ volatile ("fsave %0"
501 : : "m" (*sc->sc_fpstate) : "memory");
502 } else {
503 __asm__ volatile (".chip 68k/68881\n\t"
504 "fsave %0\n\t"
505 ".chip 68k"
506 : : "m" (*sc->sc_fpstate) : "memory");
507 }
508
509 if (CPU_IS_060 ? sc->sc_fpstate[2] : sc->sc_fpstate[0]) {
510 fpu_version = sc->sc_fpstate[0];
511 if (CPU_IS_020_OR_030 &&
512 regs->vector >= (VEC_FPBRUC * 4) &&
513 regs->vector <= (VEC_FPNAN * 4)) {
514 /* Clear pending exception in 68882 idle frame */
515 if (*(unsigned short *) sc->sc_fpstate == 0x1f38)
516 sc->sc_fpstate[0x38] |= 1 << 3;
517 }
518
519 if (CPU_IS_COLDFIRE) {
520 __asm__ volatile ("fmovemd %%fp0-%%fp1,%0\n\t"
521 "fmovel %%fpcr,%1\n\t"
522 "fmovel %%fpsr,%2\n\t"
523 "fmovel %%fpiar,%3"
524 : "=m" (sc->sc_fpregs[0]),
525 "=m" (sc->sc_fpcntl[0]),
526 "=m" (sc->sc_fpcntl[1]),
527 "=m" (sc->sc_fpcntl[2])
528 : /* no inputs */
529 : "memory");
530 } else {
531 __asm__ volatile (".chip 68k/68881\n\t"
532 "fmovemx %%fp0-%%fp1,%0\n\t"
533 "fmoveml %%fpcr/%%fpsr/%%fpiar,%1\n\t"
534 ".chip 68k"
535 : "=m" (*sc->sc_fpregs),
536 "=m" (*sc->sc_fpcntl)
537 : /* no inputs */
538 : "memory");
539 }
540 }
541 }
542
543 static inline int rt_save_fpu_state(struct ucontext __user *uc, struct pt_regs *regs)
544 {
545 unsigned char fpstate[FPCONTEXT_SIZE];
546 int context_size = CPU_IS_060 ? 8 : (CPU_IS_COLDFIRE ? 12 : 0);
547 int err = 0;
548
549 if (FPU_IS_EMU) {
550 /* save fpu control register */
551 err |= copy_to_user(uc->uc_mcontext.fpregs.f_fpcntl,
552 current->thread.fpcntl, 12);
553 /* save all other fpu register */
554 err |= copy_to_user(uc->uc_mcontext.fpregs.f_fpregs,
555 current->thread.fp, 96);
556 return err;
557 }
558
559 if (CPU_IS_COLDFIRE) {
560 __asm__ volatile ("fsave %0" : : "m" (*fpstate) : "memory");
561 } else {
562 __asm__ volatile (".chip 68k/68881\n\t"
563 "fsave %0\n\t"
564 ".chip 68k"
565 : : "m" (*fpstate) : "memory");
566 }
567
568 err |= __put_user(*(long *)fpstate, (long __user *)&uc->uc_fpstate);
569 if (CPU_IS_060 ? fpstate[2] : fpstate[0]) {
570 fpregset_t fpregs;
571 if (!(CPU_IS_060 || CPU_IS_COLDFIRE))
572 context_size = fpstate[1];
573 fpu_version = fpstate[0];
574 if (CPU_IS_020_OR_030 &&
575 regs->vector >= (VEC_FPBRUC * 4) &&
576 regs->vector <= (VEC_FPNAN * 4)) {
577 /* Clear pending exception in 68882 idle frame */
578 if (*(unsigned short *) fpstate == 0x1f38)
579 fpstate[0x38] |= 1 << 3;
580 }
581 if (CPU_IS_COLDFIRE) {
582 __asm__ volatile ("fmovemd %%fp0-%%fp7,%0\n\t"
583 "fmovel %%fpcr,%1\n\t"
584 "fmovel %%fpsr,%2\n\t"
585 "fmovel %%fpiar,%3"
586 : "=m" (fpregs.f_fpregs[0]),
587 "=m" (fpregs.f_fpcntl[0]),
588 "=m" (fpregs.f_fpcntl[1]),
589 "=m" (fpregs.f_fpcntl[2])
590 : /* no inputs */
591 : "memory");
592 } else {
593 __asm__ volatile (".chip 68k/68881\n\t"
594 "fmovemx %%fp0-%%fp7,%0\n\t"
595 "fmoveml %%fpcr/%%fpsr/%%fpiar,%1\n\t"
596 ".chip 68k"
597 : "=m" (*fpregs.f_fpregs),
598 "=m" (*fpregs.f_fpcntl)
599 : /* no inputs */
600 : "memory");
601 }
602 err |= copy_to_user(&uc->uc_mcontext.fpregs, &fpregs,
603 sizeof(fpregs));
604 }
605 if (context_size)
606 err |= copy_to_user((long __user *)&uc->uc_fpstate + 1, fpstate + 4,
607 context_size);
608 return err;
609 }
610
611 #else /* CONFIG_FPU */
612
613 /*
614 * For the case with no FPU configured these all do nothing.
615 */
616 static inline int restore_fpu_state(struct sigcontext *sc)
617 {
618 return 0;
619 }
620
621 static inline int rt_restore_fpu_state(struct ucontext __user *uc)
622 {
623 return 0;
624 }
625
626 static inline void save_fpu_state(struct sigcontext *sc, struct pt_regs *regs)
627 {
628 }
629
630 static inline int rt_save_fpu_state(struct ucontext __user *uc, struct pt_regs *regs)
631 {
632 return 0;
633 }
634
635 #endif /* CONFIG_FPU */
636
637 static int mangle_kernel_stack(struct pt_regs *regs, int formatvec,
638 void __user *fp)
639 {
640 int fsize = frame_extra_sizes(formatvec >> 12);
641 if (fsize < 0) {
642 /*
643 * user process trying to return with weird frame format
644 */
645 #ifdef DEBUG
646 printk("user process returning with weird frame format\n");
647 #endif
648 return 1;
649 }
650 if (!fsize) {
651 regs->format = formatvec >> 12;
652 regs->vector = formatvec & 0xfff;
653 } else {
654 struct switch_stack *sw = (struct switch_stack *)regs - 1;
655 unsigned long buf[fsize / 2]; /* yes, twice as much */
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 /* Always make any pending restarted system calls return -EINTR */
701 current_thread_info()->restart_block.fn = do_no_restart_syscall;
702
703 /* get previous context */
704 if (copy_from_user(&context, usc, sizeof(context)))
705 goto badframe;
706
707 /* restore passed registers */
708 regs->d0 = context.sc_d0;
709 regs->d1 = context.sc_d1;
710 regs->a0 = context.sc_a0;
711 regs->a1 = context.sc_a1;
712 regs->sr = (regs->sr & 0xff00) | (context.sc_sr & 0xff);
713 regs->pc = context.sc_pc;
714 regs->orig_d0 = -1; /* disable syscall checks */
715 wrusp(context.sc_usp);
716 formatvec = context.sc_formatvec;
717
718 err = restore_fpu_state(&context);
719
720 if (err || mangle_kernel_stack(regs, formatvec, fp))
721 goto badframe;
722
723 return 0;
724
725 badframe:
726 return 1;
727 }
728
729 static inline int
730 rt_restore_ucontext(struct pt_regs *regs, struct switch_stack *sw,
731 struct ucontext __user *uc)
732 {
733 int temp;
734 greg_t __user *gregs = uc->uc_mcontext.gregs;
735 unsigned long usp;
736 int err;
737
738 /* Always make any pending restarted system calls return -EINTR */
739 current_thread_info()->restart_block.fn = do_no_restart_syscall;
740
741 err = __get_user(temp, &uc->uc_mcontext.version);
742 if (temp != MCONTEXT_VERSION)
743 goto badframe;
744 /* restore passed registers */
745 err |= __get_user(regs->d0, &gregs[0]);
746 err |= __get_user(regs->d1, &gregs[1]);
747 err |= __get_user(regs->d2, &gregs[2]);
748 err |= __get_user(regs->d3, &gregs[3]);
749 err |= __get_user(regs->d4, &gregs[4]);
750 err |= __get_user(regs->d5, &gregs[5]);
751 err |= __get_user(sw->d6, &gregs[6]);
752 err |= __get_user(sw->d7, &gregs[7]);
753 err |= __get_user(regs->a0, &gregs[8]);
754 err |= __get_user(regs->a1, &gregs[9]);
755 err |= __get_user(regs->a2, &gregs[10]);
756 err |= __get_user(sw->a3, &gregs[11]);
757 err |= __get_user(sw->a4, &gregs[12]);
758 err |= __get_user(sw->a5, &gregs[13]);
759 err |= __get_user(sw->a6, &gregs[14]);
760 err |= __get_user(usp, &gregs[15]);
761 wrusp(usp);
762 err |= __get_user(regs->pc, &gregs[16]);
763 err |= __get_user(temp, &gregs[17]);
764 regs->sr = (regs->sr & 0xff00) | (temp & 0xff);
765 regs->orig_d0 = -1; /* disable syscall checks */
766 err |= __get_user(temp, &uc->uc_formatvec);
767
768 err |= rt_restore_fpu_state(uc);
769
770 if (err || do_sigaltstack(&uc->uc_stack, NULL, usp) == -EFAULT)
771 goto badframe;
772
773 if (mangle_kernel_stack(regs, temp, &uc->uc_extra))
774 goto badframe;
775
776 return 0;
777
778 badframe:
779 return 1;
780 }
781
782 asmlinkage int do_sigreturn(unsigned long __unused)
783 {
784 struct switch_stack *sw = (struct switch_stack *) &__unused;
785 struct pt_regs *regs = (struct pt_regs *) (sw + 1);
786 unsigned long usp = rdusp();
787 struct sigframe __user *frame = (struct sigframe __user *)(usp - 4);
788 sigset_t set;
789
790 if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
791 goto badframe;
792 if (__get_user(set.sig[0], &frame->sc.sc_mask) ||
793 (_NSIG_WORDS > 1 &&
794 __copy_from_user(&set.sig[1], &frame->extramask,
795 sizeof(frame->extramask))))
796 goto badframe;
797
798 sigdelsetmask(&set, ~_BLOCKABLE);
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, current);
807 return 0;
808 }
809
810 asmlinkage int do_rt_sigreturn(unsigned long __unused)
811 {
812 struct switch_stack *sw = (struct switch_stack *) &__unused;
813 struct pt_regs *regs = (struct pt_regs *) (sw + 1);
814 unsigned long usp = rdusp();
815 struct rt_sigframe __user *frame = (struct rt_sigframe __user *)(usp - 4);
816 sigset_t set;
817
818 if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
819 goto badframe;
820 if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set)))
821 goto badframe;
822
823 sigdelsetmask(&set, ~_BLOCKABLE);
824 set_current_blocked(&set);
825
826 if (rt_restore_ucontext(regs, sw, &frame->uc))
827 goto badframe;
828 return regs->d0;
829
830 badframe:
831 force_sig(SIGSEGV, current);
832 return 0;
833 }
834
835 static void setup_sigcontext(struct sigcontext *sc, struct pt_regs *regs,
836 unsigned long mask)
837 {
838 sc->sc_mask = mask;
839 sc->sc_usp = rdusp();
840 sc->sc_d0 = regs->d0;
841 sc->sc_d1 = regs->d1;
842 sc->sc_a0 = regs->a0;
843 sc->sc_a1 = regs->a1;
844 sc->sc_sr = regs->sr;
845 sc->sc_pc = regs->pc;
846 sc->sc_formatvec = regs->format << 12 | regs->vector;
847 save_a5_state(sc, regs);
848 save_fpu_state(sc, regs);
849 }
850
851 static inline int rt_setup_ucontext(struct ucontext __user *uc, struct pt_regs *regs)
852 {
853 struct switch_stack *sw = (struct switch_stack *)regs - 1;
854 greg_t __user *gregs = uc->uc_mcontext.gregs;
855 int err = 0;
856
857 err |= __put_user(MCONTEXT_VERSION, &uc->uc_mcontext.version);
858 err |= __put_user(regs->d0, &gregs[0]);
859 err |= __put_user(regs->d1, &gregs[1]);
860 err |= __put_user(regs->d2, &gregs[2]);
861 err |= __put_user(regs->d3, &gregs[3]);
862 err |= __put_user(regs->d4, &gregs[4]);
863 err |= __put_user(regs->d5, &gregs[5]);
864 err |= __put_user(sw->d6, &gregs[6]);
865 err |= __put_user(sw->d7, &gregs[7]);
866 err |= __put_user(regs->a0, &gregs[8]);
867 err |= __put_user(regs->a1, &gregs[9]);
868 err |= __put_user(regs->a2, &gregs[10]);
869 err |= __put_user(sw->a3, &gregs[11]);
870 err |= __put_user(sw->a4, &gregs[12]);
871 err |= __put_user(sw->a5, &gregs[13]);
872 err |= __put_user(sw->a6, &gregs[14]);
873 err |= __put_user(rdusp(), &gregs[15]);
874 err |= __put_user(regs->pc, &gregs[16]);
875 err |= __put_user(regs->sr, &gregs[17]);
876 err |= __put_user((regs->format << 12) | regs->vector, &uc->uc_formatvec);
877 err |= rt_save_fpu_state(uc, regs);
878 return err;
879 }
880
881 static inline void __user *
882 get_sigframe(struct k_sigaction *ka, struct pt_regs *regs, size_t frame_size)
883 {
884 unsigned long usp;
885
886 /* Default to using normal stack. */
887 usp = rdusp();
888
889 /* This is the X/Open sanctioned signal stack switching. */
890 if (ka->sa.sa_flags & SA_ONSTACK) {
891 if (!sas_ss_flags(usp))
892 usp = current->sas_ss_sp + current->sas_ss_size;
893 }
894 return (void __user *)((usp - frame_size) & -8UL);
895 }
896
897 static int setup_frame (int sig, struct k_sigaction *ka,
898 sigset_t *set, struct pt_regs *regs)
899 {
900 struct sigframe __user *frame;
901 int fsize = frame_extra_sizes(regs->format);
902 struct sigcontext context;
903 int err = 0;
904
905 if (fsize < 0) {
906 #ifdef DEBUG
907 printk ("setup_frame: Unknown frame format %#x\n",
908 regs->format);
909 #endif
910 goto give_sigsegv;
911 }
912
913 frame = get_sigframe(ka, regs, sizeof(*frame) + fsize);
914
915 if (fsize)
916 err |= copy_to_user (frame + 1, regs + 1, fsize);
917
918 err |= __put_user((current_thread_info()->exec_domain
919 && current_thread_info()->exec_domain->signal_invmap
920 && sig < 32
921 ? current_thread_info()->exec_domain->signal_invmap[sig]
922 : sig),
923 &frame->sig);
924
925 err |= __put_user(regs->vector, &frame->code);
926 err |= __put_user(&frame->sc, &frame->psc);
927
928 if (_NSIG_WORDS > 1)
929 err |= copy_to_user(frame->extramask, &set->sig[1],
930 sizeof(frame->extramask));
931
932 setup_sigcontext(&context, regs, set->sig[0]);
933 err |= copy_to_user (&frame->sc, &context, sizeof(context));
934
935 /* Set up to return from userspace. */
936 #ifdef CONFIG_MMU
937 err |= __put_user(frame->retcode, &frame->pretcode);
938 /* moveq #,d0; trap #0 */
939 err |= __put_user(0x70004e40 + (__NR_sigreturn << 16),
940 (long __user *)(frame->retcode));
941 #else
942 err |= __put_user((void *) ret_from_user_signal, &frame->pretcode);
943 #endif
944
945 if (err)
946 goto give_sigsegv;
947
948 push_cache ((unsigned long) &frame->retcode);
949
950 /*
951 * Set up registers for signal handler. All the state we are about
952 * to destroy is successfully copied to sigframe.
953 */
954 wrusp ((unsigned long) frame);
955 regs->pc = (unsigned long) ka->sa.sa_handler;
956 adjustformat(regs);
957
958 /*
959 * This is subtle; if we build more than one sigframe, all but the
960 * first one will see frame format 0 and have fsize == 0, so we won't
961 * screw stkadj.
962 */
963 if (fsize)
964 regs->stkadj = fsize;
965
966 /* Prepare to skip over the extra stuff in the exception frame. */
967 if (regs->stkadj) {
968 struct pt_regs *tregs =
969 (struct pt_regs *)((ulong)regs + regs->stkadj);
970 #ifdef DEBUG
971 printk("Performing stackadjust=%04x\n", regs->stkadj);
972 #endif
973 /* This must be copied with decreasing addresses to
974 handle overlaps. */
975 tregs->vector = 0;
976 tregs->format = 0;
977 tregs->pc = regs->pc;
978 tregs->sr = regs->sr;
979 }
980 return 0;
981
982 give_sigsegv:
983 force_sigsegv(sig, current);
984 return err;
985 }
986
987 static int setup_rt_frame (int sig, struct k_sigaction *ka, siginfo_t *info,
988 sigset_t *set, struct pt_regs *regs)
989 {
990 struct rt_sigframe __user *frame;
991 int fsize = frame_extra_sizes(regs->format);
992 int err = 0;
993
994 if (fsize < 0) {
995 #ifdef DEBUG
996 printk ("setup_frame: Unknown frame format %#x\n",
997 regs->format);
998 #endif
999 goto give_sigsegv;
1000 }
1001
1002 frame = get_sigframe(ka, regs, sizeof(*frame));
1003
1004 if (fsize)
1005 err |= copy_to_user (&frame->uc.uc_extra, regs + 1, fsize);
1006
1007 err |= __put_user((current_thread_info()->exec_domain
1008 && current_thread_info()->exec_domain->signal_invmap
1009 && sig < 32
1010 ? current_thread_info()->exec_domain->signal_invmap[sig]
1011 : sig),
1012 &frame->sig);
1013 err |= __put_user(&frame->info, &frame->pinfo);
1014 err |= __put_user(&frame->uc, &frame->puc);
1015 err |= copy_siginfo_to_user(&frame->info, info);
1016
1017 /* Create the ucontext. */
1018 err |= __put_user(0, &frame->uc.uc_flags);
1019 err |= __put_user(NULL, &frame->uc.uc_link);
1020 err |= __put_user((void __user *)current->sas_ss_sp,
1021 &frame->uc.uc_stack.ss_sp);
1022 err |= __put_user(sas_ss_flags(rdusp()),
1023 &frame->uc.uc_stack.ss_flags);
1024 err |= __put_user(current->sas_ss_size, &frame->uc.uc_stack.ss_size);
1025 err |= rt_setup_ucontext(&frame->uc, regs);
1026 err |= copy_to_user (&frame->uc.uc_sigmask, set, sizeof(*set));
1027
1028 /* Set up to return from userspace. */
1029 #ifdef CONFIG_MMU
1030 err |= __put_user(frame->retcode, &frame->pretcode);
1031 #ifdef __mcoldfire__
1032 /* movel #__NR_rt_sigreturn,d0; trap #0 */
1033 err |= __put_user(0x203c0000, (long __user *)(frame->retcode + 0));
1034 err |= __put_user(0x00004e40 + (__NR_rt_sigreturn << 16),
1035 (long __user *)(frame->retcode + 4));
1036 #else
1037 /* moveq #,d0; notb d0; trap #0 */
1038 err |= __put_user(0x70004600 + ((__NR_rt_sigreturn ^ 0xff) << 16),
1039 (long __user *)(frame->retcode + 0));
1040 err |= __put_user(0x4e40, (short __user *)(frame->retcode + 4));
1041 #endif
1042 #else
1043 err |= __put_user((void *) ret_from_user_rt_signal, &frame->pretcode);
1044 #endif /* CONFIG_MMU */
1045
1046 if (err)
1047 goto give_sigsegv;
1048
1049 push_cache ((unsigned long) &frame->retcode);
1050
1051 /*
1052 * Set up registers for signal handler. All the state we are about
1053 * to destroy is successfully copied to sigframe.
1054 */
1055 wrusp ((unsigned long) frame);
1056 regs->pc = (unsigned long) ka->sa.sa_handler;
1057 adjustformat(regs);
1058
1059 /*
1060 * This is subtle; if we build more than one sigframe, all but the
1061 * first one will see frame format 0 and have fsize == 0, so we won't
1062 * screw stkadj.
1063 */
1064 if (fsize)
1065 regs->stkadj = fsize;
1066
1067 /* Prepare to skip over the extra stuff in the exception frame. */
1068 if (regs->stkadj) {
1069 struct pt_regs *tregs =
1070 (struct pt_regs *)((ulong)regs + regs->stkadj);
1071 #ifdef DEBUG
1072 printk("Performing stackadjust=%04x\n", regs->stkadj);
1073 #endif
1074 /* This must be copied with decreasing addresses to
1075 handle overlaps. */
1076 tregs->vector = 0;
1077 tregs->format = 0;
1078 tregs->pc = regs->pc;
1079 tregs->sr = regs->sr;
1080 }
1081 return 0;
1082
1083 give_sigsegv:
1084 force_sigsegv(sig, current);
1085 return err;
1086 }
1087
1088 static inline void
1089 handle_restart(struct pt_regs *regs, struct k_sigaction *ka, int has_handler)
1090 {
1091 switch (regs->d0) {
1092 case -ERESTARTNOHAND:
1093 if (!has_handler)
1094 goto do_restart;
1095 regs->d0 = -EINTR;
1096 break;
1097
1098 case -ERESTART_RESTARTBLOCK:
1099 if (!has_handler) {
1100 regs->d0 = __NR_restart_syscall;
1101 regs->pc -= 2;
1102 break;
1103 }
1104 regs->d0 = -EINTR;
1105 break;
1106
1107 case -ERESTARTSYS:
1108 if (has_handler && !(ka->sa.sa_flags & SA_RESTART)) {
1109 regs->d0 = -EINTR;
1110 break;
1111 }
1112 /* fallthrough */
1113 case -ERESTARTNOINTR:
1114 do_restart:
1115 regs->d0 = regs->orig_d0;
1116 regs->pc -= 2;
1117 break;
1118 }
1119 }
1120
1121 /*
1122 * OK, we're invoking a handler
1123 */
1124 static void
1125 handle_signal(int sig, struct k_sigaction *ka, siginfo_t *info,
1126 sigset_t *oldset, struct pt_regs *regs)
1127 {
1128 int err;
1129 /* are we from a system call? */
1130 if (regs->orig_d0 >= 0)
1131 /* If so, check system call restarting.. */
1132 handle_restart(regs, ka, 1);
1133
1134 /* set up the stack frame */
1135 if (ka->sa.sa_flags & SA_SIGINFO)
1136 err = setup_rt_frame(sig, ka, info, oldset, regs);
1137 else
1138 err = setup_frame(sig, ka, oldset, regs);
1139
1140 if (err)
1141 return;
1142
1143 block_sigmask(ka, sig);
1144
1145 if (test_thread_flag(TIF_DELAYED_TRACE)) {
1146 regs->sr &= ~0x8000;
1147 send_sig(SIGTRAP, current, 1);
1148 }
1149
1150 clear_thread_flag(TIF_RESTORE_SIGMASK);
1151 }
1152
1153 /*
1154 * Note that 'init' is a special process: it doesn't get signals it doesn't
1155 * want to handle. Thus you cannot kill init even with a SIGKILL even by
1156 * mistake.
1157 */
1158 static void do_signal(struct pt_regs *regs)
1159 {
1160 siginfo_t info;
1161 struct k_sigaction ka;
1162 int signr;
1163 sigset_t *oldset;
1164
1165 current->thread.esp0 = (unsigned long) regs;
1166
1167 if (test_thread_flag(TIF_RESTORE_SIGMASK))
1168 oldset = &current->saved_sigmask;
1169 else
1170 oldset = &current->blocked;
1171
1172 signr = get_signal_to_deliver(&info, &ka, regs, NULL);
1173 if (signr > 0) {
1174 /* Whee! Actually deliver the signal. */
1175 handle_signal(signr, &ka, &info, oldset, regs);
1176 return;
1177 }
1178
1179 /* Did we come from a system call? */
1180 if (regs->orig_d0 >= 0)
1181 /* Restart the system call - no handlers present */
1182 handle_restart(regs, NULL, 0);
1183
1184 /* If there's no signal to deliver, we just restore the saved mask. */
1185 restore_saved_sigmask();
1186 }
1187
1188 void do_notify_resume(struct pt_regs *regs)
1189 {
1190 if (test_thread_flag(TIF_SIGPENDING))
1191 do_signal(regs);
1192
1193 if (test_and_clear_thread_flag(TIF_NOTIFY_RESUME))
1194 tracehook_notify_resume(regs);
1195 }
Linux kernel - Deliverables
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