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/traps.h>
51 #include <asm/ucontext.h>
52 #include <asm/cacheflush.h>
53
54 #ifdef CONFIG_MMU
55
56 /*
57 * Handle the slight differences in classic 68k and ColdFire trap frames.
58 */
59 #ifdef CONFIG_COLDFIRE
60 #define FORMAT 4
61 #define FMT4SIZE 0
62 #else
63 #define FORMAT 0
64 #define FMT4SIZE sizeof_field(struct frame, un.fmt4)
65 #endif
66
67 static const int frame_size_change[16] = {
68 [1] = -1, /* sizeof_field(struct frame, un.fmt1), */
69 [2] = sizeof_field(struct frame, un.fmt2),
70 [3] = sizeof_field(struct frame, un.fmt3),
71 [4] = FMT4SIZE,
72 [5] = -1, /* sizeof_field(struct frame, un.fmt5), */
73 [6] = -1, /* sizeof_field(struct frame, un.fmt6), */
74 [7] = sizeof_field(struct frame, un.fmt7),
75 [8] = -1, /* sizeof_field(struct frame, un.fmt8), */
76 [9] = sizeof_field(struct frame, un.fmt9),
77 [10] = sizeof_field(struct frame, un.fmta),
78 [11] = sizeof_field(struct frame, un.fmtb),
79 [12] = -1, /* sizeof_field(struct frame, un.fmtc), */
80 [13] = -1, /* sizeof_field(struct frame, un.fmtd), */
81 [14] = -1, /* sizeof_field(struct frame, un.fmte), */
82 [15] = -1, /* sizeof_field(struct frame, un.fmtf), */
83 };
84
frame_extra_sizes(int f)85 static inline int frame_extra_sizes(int f)
86 {
87 return frame_size_change[f];
88 }
89
fixup_exception(struct pt_regs * regs)90 int fixup_exception(struct pt_regs *regs)
91 {
92 const struct exception_table_entry *fixup;
93 struct pt_regs *tregs;
94
95 /* Are we prepared to handle this kernel fault? */
96 fixup = search_exception_tables(regs->pc);
97 if (!fixup)
98 return 0;
99
100 /* Create a new four word stack frame, discarding the old one. */
101 regs->stkadj = frame_extra_sizes(regs->format);
102 tregs = (struct pt_regs *)((long)regs + regs->stkadj);
103 tregs->vector = regs->vector;
104 tregs->format = FORMAT;
105 tregs->pc = fixup->fixup;
106 tregs->sr = regs->sr;
107
108 return 1;
109 }
110
push_cache(unsigned long vaddr)111 static inline void push_cache (unsigned long vaddr)
112 {
113 /*
114 * Using the old cache_push_v() was really a big waste.
115 *
116 * What we are trying to do is to flush 8 bytes to ram.
117 * Flushing 2 cache lines of 16 bytes is much cheaper than
118 * flushing 1 or 2 pages, as previously done in
119 * cache_push_v().
120 * Jes
121 */
122 if (CPU_IS_040) {
123 unsigned long temp;
124
125 __asm__ __volatile__ (".chip 68040\n\t"
126 "nop\n\t"
127 "ptestr (%1)\n\t"
128 "movec %%mmusr,%0\n\t"
129 ".chip 68k"
130 : "=r" (temp)
131 : "a" (vaddr));
132
133 temp &= PAGE_MASK;
134 temp |= vaddr & ~PAGE_MASK;
135
136 __asm__ __volatile__ (".chip 68040\n\t"
137 "nop\n\t"
138 "cpushl %%bc,(%0)\n\t"
139 ".chip 68k"
140 : : "a" (temp));
141 }
142 else if (CPU_IS_060) {
143 unsigned long temp;
144 __asm__ __volatile__ (".chip 68060\n\t"
145 "plpar (%0)\n\t"
146 ".chip 68k"
147 : "=a" (temp)
148 : "0" (vaddr));
149 __asm__ __volatile__ (".chip 68060\n\t"
150 "cpushl %%bc,(%0)\n\t"
151 ".chip 68k"
152 : : "a" (temp));
153 } else if (!CPU_IS_COLDFIRE) {
154 /*
155 * 68030/68020 have no writeback cache;
156 * still need to clear icache.
157 * Note that vaddr is guaranteed to be long word aligned.
158 */
159 unsigned long temp;
160 asm volatile ("movec %%cacr,%0" : "=r" (temp));
161 temp += 4;
162 asm volatile ("movec %0,%%caar\n\t"
163 "movec %1,%%cacr"
164 : : "r" (vaddr), "r" (temp));
165 asm volatile ("movec %0,%%caar\n\t"
166 "movec %1,%%cacr"
167 : : "r" (vaddr + 4), "r" (temp));
168 } else {
169 /* CPU_IS_COLDFIRE */
170 #if defined(CONFIG_CACHE_COPYBACK)
171 flush_cf_dcache(0, DCACHE_MAX_ADDR);
172 #endif
173 /* Invalidate instruction cache for the pushed bytes */
174 clear_cf_icache(vaddr, vaddr + 8);
175 }
176 }
177
adjustformat(struct pt_regs * regs)178 static inline void adjustformat(struct pt_regs *regs)
179 {
180 }
181
save_a5_state(struct sigcontext * sc,struct pt_regs * regs)182 static inline void save_a5_state(struct sigcontext *sc, struct pt_regs *regs)
183 {
184 }
185
186 #else /* CONFIG_MMU */
187
188 void ret_from_user_signal(void);
189 void ret_from_user_rt_signal(void);
190
frame_extra_sizes(int f)191 static inline int frame_extra_sizes(int f)
192 {
193 /* No frame size adjustments required on non-MMU CPUs */
194 return 0;
195 }
196
adjustformat(struct pt_regs * regs)197 static inline void adjustformat(struct pt_regs *regs)
198 {
199 /*
200 * set format byte to make stack appear modulo 4, which it will
201 * be when doing the rte
202 */
203 regs->format = 0x4;
204 }
205
save_a5_state(struct sigcontext * sc,struct pt_regs * regs)206 static inline void save_a5_state(struct sigcontext *sc, struct pt_regs *regs)
207 {
208 sc->sc_a5 = ((struct switch_stack *)regs - 1)->a5;
209 }
210
push_cache(unsigned long vaddr)211 static inline void push_cache(unsigned long vaddr)
212 {
213 }
214
215 #endif /* CONFIG_MMU */
216
217 /*
218 * Do a signal return; undo the signal stack.
219 *
220 * Keep the return code on the stack quadword aligned!
221 * That makes the cache flush below easier.
222 */
223
224 struct sigframe
225 {
226 char __user *pretcode;
227 int sig;
228 int code;
229 struct sigcontext __user *psc;
230 char retcode[8];
231 unsigned long extramask[_NSIG_WORDS-1];
232 struct sigcontext sc;
233 };
234
235 struct rt_sigframe
236 {
237 char __user *pretcode;
238 int sig;
239 struct siginfo __user *pinfo;
240 void __user *puc;
241 char retcode[8];
242 struct siginfo info;
243 struct ucontext uc;
244 };
245
246 #define FPCONTEXT_SIZE 216
247 #define uc_fpstate uc_filler[0]
248 #define uc_formatvec uc_filler[FPCONTEXT_SIZE/4]
249 #define uc_extra uc_filler[FPCONTEXT_SIZE/4+1]
250
251 #ifdef CONFIG_FPU
252
253 static unsigned char fpu_version; /* version number of fpu, set by setup_frame */
254
restore_fpu_state(struct sigcontext * sc)255 static inline int restore_fpu_state(struct sigcontext *sc)
256 {
257 int err = 1;
258
259 if (FPU_IS_EMU) {
260 /* restore registers */
261 memcpy(current->thread.fpcntl, sc->sc_fpcntl, 12);
262 memcpy(current->thread.fp, sc->sc_fpregs, 24);
263 return 0;
264 }
265
266 if (CPU_IS_060 ? sc->sc_fpstate[2] : sc->sc_fpstate[0]) {
267 /* Verify the frame format. */
268 if (!(CPU_IS_060 || CPU_IS_COLDFIRE) &&
269 (sc->sc_fpstate[0] != fpu_version))
270 goto out;
271 if (CPU_IS_020_OR_030) {
272 if (m68k_fputype & FPU_68881 &&
273 !(sc->sc_fpstate[1] == 0x18 || sc->sc_fpstate[1] == 0xb4))
274 goto out;
275 if (m68k_fputype & FPU_68882 &&
276 !(sc->sc_fpstate[1] == 0x38 || sc->sc_fpstate[1] == 0xd4))
277 goto out;
278 } else if (CPU_IS_040) {
279 if (!(sc->sc_fpstate[1] == 0x00 ||
280 sc->sc_fpstate[1] == 0x28 ||
281 sc->sc_fpstate[1] == 0x60))
282 goto out;
283 } else if (CPU_IS_060) {
284 if (!(sc->sc_fpstate[3] == 0x00 ||
285 sc->sc_fpstate[3] == 0x60 ||
286 sc->sc_fpstate[3] == 0xe0))
287 goto out;
288 } else if (CPU_IS_COLDFIRE) {
289 if (!(sc->sc_fpstate[0] == 0x00 ||
290 sc->sc_fpstate[0] == 0x05 ||
291 sc->sc_fpstate[0] == 0xe5))
292 goto out;
293 } else
294 goto out;
295
296 if (CPU_IS_COLDFIRE) {
297 __asm__ volatile ("fmovemd %0,%%fp0-%%fp1\n\t"
298 "fmovel %1,%%fpcr\n\t"
299 "fmovel %2,%%fpsr\n\t"
300 "fmovel %3,%%fpiar"
301 : /* no outputs */
302 : "m" (sc->sc_fpregs[0]),
303 "m" (sc->sc_fpcntl[0]),
304 "m" (sc->sc_fpcntl[1]),
305 "m" (sc->sc_fpcntl[2]));
306 } else {
307 __asm__ volatile (".chip 68k/68881\n\t"
308 "fmovemx %0,%%fp0-%%fp1\n\t"
309 "fmoveml %1,%%fpcr/%%fpsr/%%fpiar\n\t"
310 ".chip 68k"
311 : /* no outputs */
312 : "m" (*sc->sc_fpregs),
313 "m" (*sc->sc_fpcntl));
314 }
315 }
316
317 if (CPU_IS_COLDFIRE) {
318 __asm__ volatile ("frestore %0" : : "m" (*sc->sc_fpstate));
319 } else {
320 __asm__ volatile (".chip 68k/68881\n\t"
321 "frestore %0\n\t"
322 ".chip 68k"
323 : : "m" (*sc->sc_fpstate));
324 }
325 err = 0;
326
327 out:
328 return err;
329 }
330
rt_restore_fpu_state(struct ucontext __user * uc)331 static inline int rt_restore_fpu_state(struct ucontext __user *uc)
332 {
333 unsigned char fpstate[FPCONTEXT_SIZE];
334 int context_size = CPU_IS_060 ? 8 : (CPU_IS_COLDFIRE ? 12 : 0);
335 fpregset_t fpregs;
336 int err = 1;
337
338 if (FPU_IS_EMU) {
339 /* restore fpu control register */
340 if (__copy_from_user(current->thread.fpcntl,
341 uc->uc_mcontext.fpregs.f_fpcntl, 12))
342 goto out;
343 /* restore all other fpu register */
344 if (__copy_from_user(current->thread.fp,
345 uc->uc_mcontext.fpregs.f_fpregs, 96))
346 goto out;
347 return 0;
348 }
349
350 if (__get_user(*(long *)fpstate, (long __user *)&uc->uc_fpstate))
351 goto out;
352 if (CPU_IS_060 ? fpstate[2] : fpstate[0]) {
353 if (!(CPU_IS_060 || CPU_IS_COLDFIRE))
354 context_size = fpstate[1];
355 /* Verify the frame format. */
356 if (!(CPU_IS_060 || CPU_IS_COLDFIRE) &&
357 (fpstate[0] != fpu_version))
358 goto out;
359 if (CPU_IS_020_OR_030) {
360 if (m68k_fputype & FPU_68881 &&
361 !(context_size == 0x18 || context_size == 0xb4))
362 goto out;
363 if (m68k_fputype & FPU_68882 &&
364 !(context_size == 0x38 || context_size == 0xd4))
365 goto out;
366 } else if (CPU_IS_040) {
367 if (!(context_size == 0x00 ||
368 context_size == 0x28 ||
369 context_size == 0x60))
370 goto out;
371 } else if (CPU_IS_060) {
372 if (!(fpstate[3] == 0x00 ||
373 fpstate[3] == 0x60 ||
374 fpstate[3] == 0xe0))
375 goto out;
376 } else if (CPU_IS_COLDFIRE) {
377 if (!(fpstate[3] == 0x00 ||
378 fpstate[3] == 0x05 ||
379 fpstate[3] == 0xe5))
380 goto out;
381 } else
382 goto out;
383 if (__copy_from_user(&fpregs, &uc->uc_mcontext.fpregs,
384 sizeof(fpregs)))
385 goto out;
386
387 if (CPU_IS_COLDFIRE) {
388 __asm__ volatile ("fmovemd %0,%%fp0-%%fp7\n\t"
389 "fmovel %1,%%fpcr\n\t"
390 "fmovel %2,%%fpsr\n\t"
391 "fmovel %3,%%fpiar"
392 : /* no outputs */
393 : "m" (fpregs.f_fpregs[0]),
394 "m" (fpregs.f_fpcntl[0]),
395 "m" (fpregs.f_fpcntl[1]),
396 "m" (fpregs.f_fpcntl[2]));
397 } else {
398 __asm__ volatile (".chip 68k/68881\n\t"
399 "fmovemx %0,%%fp0-%%fp7\n\t"
400 "fmoveml %1,%%fpcr/%%fpsr/%%fpiar\n\t"
401 ".chip 68k"
402 : /* no outputs */
403 : "m" (*fpregs.f_fpregs),
404 "m" (*fpregs.f_fpcntl));
405 }
406 }
407 if (context_size &&
408 __copy_from_user(fpstate + 4, (long __user *)&uc->uc_fpstate + 1,
409 context_size))
410 goto out;
411
412 if (CPU_IS_COLDFIRE) {
413 __asm__ volatile ("frestore %0" : : "m" (*fpstate));
414 } else {
415 __asm__ volatile (".chip 68k/68881\n\t"
416 "frestore %0\n\t"
417 ".chip 68k"
418 : : "m" (*fpstate));
419 }
420 err = 0;
421
422 out:
423 return err;
424 }
425
426 /*
427 * Set up a signal frame.
428 */
save_fpu_state(struct sigcontext * sc,struct pt_regs * regs)429 static inline void save_fpu_state(struct sigcontext *sc, struct pt_regs *regs)
430 {
431 if (FPU_IS_EMU) {
432 /* save registers */
433 memcpy(sc->sc_fpcntl, current->thread.fpcntl, 12);
434 memcpy(sc->sc_fpregs, current->thread.fp, 24);
435 return;
436 }
437
438 if (CPU_IS_COLDFIRE) {
439 __asm__ volatile ("fsave %0"
440 : : "m" (*sc->sc_fpstate) : "memory");
441 } else {
442 __asm__ volatile (".chip 68k/68881\n\t"
443 "fsave %0\n\t"
444 ".chip 68k"
445 : : "m" (*sc->sc_fpstate) : "memory");
446 }
447
448 if (CPU_IS_060 ? sc->sc_fpstate[2] : sc->sc_fpstate[0]) {
449 fpu_version = sc->sc_fpstate[0];
450 if (CPU_IS_020_OR_030 &&
451 regs->vector >= (VEC_FPBRUC * 4) &&
452 regs->vector <= (VEC_FPNAN * 4)) {
453 /* Clear pending exception in 68882 idle frame */
454 if (*(unsigned short *) sc->sc_fpstate == 0x1f38)
455 sc->sc_fpstate[0x38] |= 1 << 3;
456 }
457
458 if (CPU_IS_COLDFIRE) {
459 __asm__ volatile ("fmovemd %%fp0-%%fp1,%0\n\t"
460 "fmovel %%fpcr,%1\n\t"
461 "fmovel %%fpsr,%2\n\t"
462 "fmovel %%fpiar,%3"
463 : "=m" (sc->sc_fpregs[0]),
464 "=m" (sc->sc_fpcntl[0]),
465 "=m" (sc->sc_fpcntl[1]),
466 "=m" (sc->sc_fpcntl[2])
467 : /* no inputs */
468 : "memory");
469 } else {
470 __asm__ volatile (".chip 68k/68881\n\t"
471 "fmovemx %%fp0-%%fp1,%0\n\t"
472 "fmoveml %%fpcr/%%fpsr/%%fpiar,%1\n\t"
473 ".chip 68k"
474 : "=m" (*sc->sc_fpregs),
475 "=m" (*sc->sc_fpcntl)
476 : /* no inputs */
477 : "memory");
478 }
479 }
480 }
481
rt_save_fpu_state(struct ucontext __user * uc,struct pt_regs * regs)482 static inline int rt_save_fpu_state(struct ucontext __user *uc, struct pt_regs *regs)
483 {
484 unsigned char fpstate[FPCONTEXT_SIZE];
485 int context_size = CPU_IS_060 ? 8 : (CPU_IS_COLDFIRE ? 12 : 0);
486 int err = 0;
487
488 if (FPU_IS_EMU) {
489 /* save fpu control register */
490 err |= copy_to_user(uc->uc_mcontext.fpregs.f_fpcntl,
491 current->thread.fpcntl, 12);
492 /* save all other fpu register */
493 err |= copy_to_user(uc->uc_mcontext.fpregs.f_fpregs,
494 current->thread.fp, 96);
495 return err;
496 }
497
498 if (CPU_IS_COLDFIRE) {
499 __asm__ volatile ("fsave %0" : : "m" (*fpstate) : "memory");
500 } else {
501 __asm__ volatile (".chip 68k/68881\n\t"
502 "fsave %0\n\t"
503 ".chip 68k"
504 : : "m" (*fpstate) : "memory");
505 }
506
507 err |= __put_user(*(long *)fpstate, (long __user *)&uc->uc_fpstate);
508 if (CPU_IS_060 ? fpstate[2] : fpstate[0]) {
509 fpregset_t fpregs;
510 if (!(CPU_IS_060 || CPU_IS_COLDFIRE))
511 context_size = fpstate[1];
512 fpu_version = fpstate[0];
513 if (CPU_IS_020_OR_030 &&
514 regs->vector >= (VEC_FPBRUC * 4) &&
515 regs->vector <= (VEC_FPNAN * 4)) {
516 /* Clear pending exception in 68882 idle frame */
517 if (*(unsigned short *) fpstate == 0x1f38)
518 fpstate[0x38] |= 1 << 3;
519 }
520 if (CPU_IS_COLDFIRE) {
521 __asm__ volatile ("fmovemd %%fp0-%%fp7,%0\n\t"
522 "fmovel %%fpcr,%1\n\t"
523 "fmovel %%fpsr,%2\n\t"
524 "fmovel %%fpiar,%3"
525 : "=m" (fpregs.f_fpregs[0]),
526 "=m" (fpregs.f_fpcntl[0]),
527 "=m" (fpregs.f_fpcntl[1]),
528 "=m" (fpregs.f_fpcntl[2])
529 : /* no inputs */
530 : "memory");
531 } else {
532 __asm__ volatile (".chip 68k/68881\n\t"
533 "fmovemx %%fp0-%%fp7,%0\n\t"
534 "fmoveml %%fpcr/%%fpsr/%%fpiar,%1\n\t"
535 ".chip 68k"
536 : "=m" (*fpregs.f_fpregs),
537 "=m" (*fpregs.f_fpcntl)
538 : /* no inputs */
539 : "memory");
540 }
541 err |= copy_to_user(&uc->uc_mcontext.fpregs, &fpregs,
542 sizeof(fpregs));
543 }
544 if (context_size)
545 err |= copy_to_user((long __user *)&uc->uc_fpstate + 1, fpstate + 4,
546 context_size);
547 return err;
548 }
549
550 #else /* CONFIG_FPU */
551
552 /*
553 * For the case with no FPU configured these all do nothing.
554 */
restore_fpu_state(struct sigcontext * sc)555 static inline int restore_fpu_state(struct sigcontext *sc)
556 {
557 return 0;
558 }
559
rt_restore_fpu_state(struct ucontext __user * uc)560 static inline int rt_restore_fpu_state(struct ucontext __user *uc)
561 {
562 return 0;
563 }
564
save_fpu_state(struct sigcontext * sc,struct pt_regs * regs)565 static inline void save_fpu_state(struct sigcontext *sc, struct pt_regs *regs)
566 {
567 }
568
rt_save_fpu_state(struct ucontext __user * uc,struct pt_regs * regs)569 static inline int rt_save_fpu_state(struct ucontext __user *uc, struct pt_regs *regs)
570 {
571 return 0;
572 }
573
574 #endif /* CONFIG_FPU */
575
siginfo_build_tests(void)576 static inline void siginfo_build_tests(void)
577 {
578 /*
579 * This needs to be tested on m68k as it has a lesser
580 * alignment requirement than x86 and that can cause surprises.
581 */
582
583 /* This is part of the ABI and can never change in size: */
584 BUILD_BUG_ON(sizeof(siginfo_t) != 128);
585
586 /* Ensure the known fields never change in location */
587 BUILD_BUG_ON(offsetof(siginfo_t, si_signo) != 0);
588 BUILD_BUG_ON(offsetof(siginfo_t, si_errno) != 4);
589 BUILD_BUG_ON(offsetof(siginfo_t, si_code) != 8);
590
591 /* _kill */
592 BUILD_BUG_ON(offsetof(siginfo_t, si_pid) != 0x0c);
593 BUILD_BUG_ON(offsetof(siginfo_t, si_uid) != 0x10);
594
595 /* _timer */
596 BUILD_BUG_ON(offsetof(siginfo_t, si_tid) != 0x0c);
597 BUILD_BUG_ON(offsetof(siginfo_t, si_overrun) != 0x10);
598 BUILD_BUG_ON(offsetof(siginfo_t, si_value) != 0x14);
599
600 /* _rt */
601 BUILD_BUG_ON(offsetof(siginfo_t, si_pid) != 0x0c);
602 BUILD_BUG_ON(offsetof(siginfo_t, si_uid) != 0x10);
603 BUILD_BUG_ON(offsetof(siginfo_t, si_value) != 0x14);
604
605 /* _sigchld */
606 BUILD_BUG_ON(offsetof(siginfo_t, si_pid) != 0x0c);
607 BUILD_BUG_ON(offsetof(siginfo_t, si_uid) != 0x10);
608 BUILD_BUG_ON(offsetof(siginfo_t, si_status) != 0x14);
609 BUILD_BUG_ON(offsetof(siginfo_t, si_utime) != 0x18);
610 BUILD_BUG_ON(offsetof(siginfo_t, si_stime) != 0x1c);
611
612 /* _sigfault */
613 BUILD_BUG_ON(offsetof(siginfo_t, si_addr) != 0x0c);
614
615 /* _sigfault._mcerr */
616 BUILD_BUG_ON(offsetof(siginfo_t, si_addr_lsb) != 0x10);
617
618 /* _sigfault._addr_bnd */
619 BUILD_BUG_ON(offsetof(siginfo_t, si_lower) != 0x12);
620 BUILD_BUG_ON(offsetof(siginfo_t, si_upper) != 0x16);
621
622 /* _sigfault._addr_pkey */
623 BUILD_BUG_ON(offsetof(siginfo_t, si_pkey) != 0x12);
624
625 /* _sigfault._perf */
626 BUILD_BUG_ON(offsetof(siginfo_t, si_perf) != 0x10);
627
628 /* _sigpoll */
629 BUILD_BUG_ON(offsetof(siginfo_t, si_band) != 0x0c);
630 BUILD_BUG_ON(offsetof(siginfo_t, si_fd) != 0x10);
631
632 /* _sigsys */
633 BUILD_BUG_ON(offsetof(siginfo_t, si_call_addr) != 0x0c);
634 BUILD_BUG_ON(offsetof(siginfo_t, si_syscall) != 0x10);
635 BUILD_BUG_ON(offsetof(siginfo_t, si_arch) != 0x14);
636
637 /* any new si_fields should be added here */
638 }
639
mangle_kernel_stack(struct pt_regs * regs,int formatvec,void __user * fp)640 static int mangle_kernel_stack(struct pt_regs *regs, int formatvec,
641 void __user *fp)
642 {
643 int fsize = frame_extra_sizes(formatvec >> 12);
644 if (fsize < 0) {
645 /*
646 * user process trying to return with weird frame format
647 */
648 pr_debug("user process returning with weird frame format\n");
649 return 1;
650 }
651 if (!fsize) {
652 regs->format = formatvec >> 12;
653 regs->vector = formatvec & 0xfff;
654 } else {
655 struct switch_stack *sw = (struct switch_stack *)regs - 1;
656 /* yes, twice as much as max(sizeof(frame.un.fmt<x>)) */
657 unsigned long buf[sizeof_field(struct frame, un) / 2];
658
659 /* that'll make sure that expansion won't crap over data */
660 if (copy_from_user(buf + fsize / 4, fp, fsize))
661 return 1;
662
663 /* point of no return */
664 regs->format = formatvec >> 12;
665 regs->vector = formatvec & 0xfff;
666 #define frame_offset (sizeof(struct pt_regs)+sizeof(struct switch_stack))
667 __asm__ __volatile__ (
668 #ifdef CONFIG_COLDFIRE
669 " movel %0,%/sp\n\t"
670 " bra ret_from_signal\n"
671 #else
672 " movel %0,%/a0\n\t"
673 " subl %1,%/a0\n\t" /* make room on stack */
674 " movel %/a0,%/sp\n\t" /* set stack pointer */
675 /* move switch_stack and pt_regs */
676 "1: movel %0@+,%/a0@+\n\t"
677 " dbra %2,1b\n\t"
678 " lea %/sp@(%c3),%/a0\n\t" /* add offset of fmt */
679 " lsrl #2,%1\n\t"
680 " subql #1,%1\n\t"
681 /* copy to the gap we'd made */
682 "2: movel %4@+,%/a0@+\n\t"
683 " dbra %1,2b\n\t"
684 " bral ret_from_signal\n"
685 #endif
686 : /* no outputs, it doesn't ever return */
687 : "a" (sw), "d" (fsize), "d" (frame_offset/4-1),
688 "n" (frame_offset), "a" (buf + fsize/4)
689 : "a0");
690 #undef frame_offset
691 }
692 return 0;
693 }
694
695 static inline int
restore_sigcontext(struct pt_regs * regs,struct sigcontext __user * usc,void __user * fp)696 restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *usc, void __user *fp)
697 {
698 int formatvec;
699 struct sigcontext context;
700 int err = 0;
701
702 siginfo_build_tests();
703
704 /* Always make any pending restarted system calls return -EINTR */
705 current->restart_block.fn = do_no_restart_syscall;
706
707 /* get previous context */
708 if (copy_from_user(&context, usc, sizeof(context)))
709 goto badframe;
710
711 /* restore passed registers */
712 regs->d0 = context.sc_d0;
713 regs->d1 = context.sc_d1;
714 regs->a0 = context.sc_a0;
715 regs->a1 = context.sc_a1;
716 regs->sr = (regs->sr & 0xff00) | (context.sc_sr & 0xff);
717 regs->pc = context.sc_pc;
718 regs->orig_d0 = -1; /* disable syscall checks */
719 wrusp(context.sc_usp);
720 formatvec = context.sc_formatvec;
721
722 err = restore_fpu_state(&context);
723
724 if (err || mangle_kernel_stack(regs, formatvec, fp))
725 goto badframe;
726
727 return 0;
728
729 badframe:
730 return 1;
731 }
732
733 static inline int
rt_restore_ucontext(struct pt_regs * regs,struct switch_stack * sw,struct ucontext __user * uc)734 rt_restore_ucontext(struct pt_regs *regs, struct switch_stack *sw,
735 struct ucontext __user *uc)
736 {
737 int temp;
738 greg_t __user *gregs = uc->uc_mcontext.gregs;
739 unsigned long usp;
740 int err;
741
742 /* Always make any pending restarted system calls return -EINTR */
743 current->restart_block.fn = do_no_restart_syscall;
744
745 err = __get_user(temp, &uc->uc_mcontext.version);
746 if (temp != MCONTEXT_VERSION)
747 goto badframe;
748 /* restore passed registers */
749 err |= __get_user(regs->d0, &gregs[0]);
750 err |= __get_user(regs->d1, &gregs[1]);
751 err |= __get_user(regs->d2, &gregs[2]);
752 err |= __get_user(regs->d3, &gregs[3]);
753 err |= __get_user(regs->d4, &gregs[4]);
754 err |= __get_user(regs->d5, &gregs[5]);
755 err |= __get_user(sw->d6, &gregs[6]);
756 err |= __get_user(sw->d7, &gregs[7]);
757 err |= __get_user(regs->a0, &gregs[8]);
758 err |= __get_user(regs->a1, &gregs[9]);
759 err |= __get_user(regs->a2, &gregs[10]);
760 err |= __get_user(sw->a3, &gregs[11]);
761 err |= __get_user(sw->a4, &gregs[12]);
762 err |= __get_user(sw->a5, &gregs[13]);
763 err |= __get_user(sw->a6, &gregs[14]);
764 err |= __get_user(usp, &gregs[15]);
765 wrusp(usp);
766 err |= __get_user(regs->pc, &gregs[16]);
767 err |= __get_user(temp, &gregs[17]);
768 regs->sr = (regs->sr & 0xff00) | (temp & 0xff);
769 regs->orig_d0 = -1; /* disable syscall checks */
770 err |= __get_user(temp, &uc->uc_formatvec);
771
772 err |= rt_restore_fpu_state(uc);
773 err |= restore_altstack(&uc->uc_stack);
774
775 if (err)
776 goto badframe;
777
778 if (mangle_kernel_stack(regs, temp, &uc->uc_extra))
779 goto badframe;
780
781 return 0;
782
783 badframe:
784 return 1;
785 }
786
do_sigreturn(struct pt_regs * regs,struct switch_stack * sw)787 asmlinkage int do_sigreturn(struct pt_regs *regs, struct switch_stack *sw)
788 {
789 unsigned long usp = rdusp();
790 struct sigframe __user *frame = (struct sigframe __user *)(usp - 4);
791 sigset_t set;
792
793 if (!access_ok(frame, sizeof(*frame)))
794 goto badframe;
795 if (__get_user(set.sig[0], &frame->sc.sc_mask) ||
796 (_NSIG_WORDS > 1 &&
797 __copy_from_user(&set.sig[1], &frame->extramask,
798 sizeof(frame->extramask))))
799 goto badframe;
800
801 set_current_blocked(&set);
802
803 if (restore_sigcontext(regs, &frame->sc, frame + 1))
804 goto badframe;
805 return regs->d0;
806
807 badframe:
808 force_sig(SIGSEGV);
809 return 0;
810 }
811
do_rt_sigreturn(struct pt_regs * regs,struct switch_stack * sw)812 asmlinkage int do_rt_sigreturn(struct pt_regs *regs, struct switch_stack *sw)
813 {
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(frame, sizeof(*frame)))
819 goto badframe;
820 if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set)))
821 goto badframe;
822
823 set_current_blocked(&set);
824
825 if (rt_restore_ucontext(regs, sw, &frame->uc))
826 goto badframe;
827 return regs->d0;
828
829 badframe:
830 force_sig(SIGSEGV);
831 return 0;
832 }
833
setup_sigcontext(struct sigcontext * sc,struct pt_regs * regs,unsigned long mask)834 static void setup_sigcontext(struct sigcontext *sc, struct pt_regs *regs,
835 unsigned long mask)
836 {
837 sc->sc_mask = mask;
838 sc->sc_usp = rdusp();
839 sc->sc_d0 = regs->d0;
840 sc->sc_d1 = regs->d1;
841 sc->sc_a0 = regs->a0;
842 sc->sc_a1 = regs->a1;
843 sc->sc_sr = regs->sr;
844 sc->sc_pc = regs->pc;
845 sc->sc_formatvec = regs->format << 12 | regs->vector;
846 save_a5_state(sc, regs);
847 save_fpu_state(sc, regs);
848 }
849
rt_setup_ucontext(struct ucontext __user * uc,struct pt_regs * regs)850 static inline int rt_setup_ucontext(struct ucontext __user *uc, struct pt_regs *regs)
851 {
852 struct switch_stack *sw = (struct switch_stack *)regs - 1;
853 greg_t __user *gregs = uc->uc_mcontext.gregs;
854 int err = 0;
855
856 err |= __put_user(MCONTEXT_VERSION, &uc->uc_mcontext.version);
857 err |= __put_user(regs->d0, &gregs[0]);
858 err |= __put_user(regs->d1, &gregs[1]);
859 err |= __put_user(regs->d2, &gregs[2]);
860 err |= __put_user(regs->d3, &gregs[3]);
861 err |= __put_user(regs->d4, &gregs[4]);
862 err |= __put_user(regs->d5, &gregs[5]);
863 err |= __put_user(sw->d6, &gregs[6]);
864 err |= __put_user(sw->d7, &gregs[7]);
865 err |= __put_user(regs->a0, &gregs[8]);
866 err |= __put_user(regs->a1, &gregs[9]);
867 err |= __put_user(regs->a2, &gregs[10]);
868 err |= __put_user(sw->a3, &gregs[11]);
869 err |= __put_user(sw->a4, &gregs[12]);
870 err |= __put_user(sw->a5, &gregs[13]);
871 err |= __put_user(sw->a6, &gregs[14]);
872 err |= __put_user(rdusp(), &gregs[15]);
873 err |= __put_user(regs->pc, &gregs[16]);
874 err |= __put_user(regs->sr, &gregs[17]);
875 err |= __put_user((regs->format << 12) | regs->vector, &uc->uc_formatvec);
876 err |= rt_save_fpu_state(uc, regs);
877 return err;
878 }
879
880 static inline void __user *
get_sigframe(struct ksignal * ksig,size_t frame_size)881 get_sigframe(struct ksignal *ksig, size_t frame_size)
882 {
883 unsigned long usp = sigsp(rdusp(), ksig);
884
885 return (void __user *)((usp - frame_size) & -8UL);
886 }
887
setup_frame(struct ksignal * ksig,sigset_t * set,struct pt_regs * regs)888 static int setup_frame(struct ksignal *ksig, sigset_t *set,
889 struct pt_regs *regs)
890 {
891 struct sigframe __user *frame;
892 int fsize = frame_extra_sizes(regs->format);
893 struct sigcontext context;
894 int err = 0, sig = ksig->sig;
895
896 if (fsize < 0) {
897 pr_debug("setup_frame: Unknown frame format %#x\n",
898 regs->format);
899 return -EFAULT;
900 }
901
902 frame = get_sigframe(ksig, sizeof(*frame) + fsize);
903
904 if (fsize)
905 err |= copy_to_user (frame + 1, regs + 1, fsize);
906
907 err |= __put_user(sig, &frame->sig);
908
909 err |= __put_user(regs->vector, &frame->code);
910 err |= __put_user(&frame->sc, &frame->psc);
911
912 if (_NSIG_WORDS > 1)
913 err |= copy_to_user(frame->extramask, &set->sig[1],
914 sizeof(frame->extramask));
915
916 setup_sigcontext(&context, regs, set->sig[0]);
917 err |= copy_to_user (&frame->sc, &context, sizeof(context));
918
919 /* Set up to return from userspace. */
920 #ifdef CONFIG_MMU
921 err |= __put_user(frame->retcode, &frame->pretcode);
922 /* moveq #,d0; trap #0 */
923 err |= __put_user(0x70004e40 + (__NR_sigreturn << 16),
924 (long __user *)(frame->retcode));
925 #else
926 err |= __put_user((long) ret_from_user_signal,
927 (long __user *) &frame->pretcode);
928 #endif
929
930 if (err)
931 return -EFAULT;
932
933 push_cache ((unsigned long) &frame->retcode);
934
935 /*
936 * Set up registers for signal handler. All the state we are about
937 * to destroy is successfully copied to sigframe.
938 */
939 wrusp ((unsigned long) frame);
940 regs->pc = (unsigned long) ksig->ka.sa.sa_handler;
941 adjustformat(regs);
942
943 /*
944 * This is subtle; if we build more than one sigframe, all but the
945 * first one will see frame format 0 and have fsize == 0, so we won't
946 * screw stkadj.
947 */
948 if (fsize)
949 regs->stkadj = fsize;
950
951 /* Prepare to skip over the extra stuff in the exception frame. */
952 if (regs->stkadj) {
953 struct pt_regs *tregs =
954 (struct pt_regs *)((ulong)regs + regs->stkadj);
955 pr_debug("Performing stackadjust=%04lx\n", regs->stkadj);
956 /* This must be copied with decreasing addresses to
957 handle overlaps. */
958 tregs->vector = 0;
959 tregs->format = 0;
960 tregs->pc = regs->pc;
961 tregs->sr = regs->sr;
962 }
963 return 0;
964 }
965
setup_rt_frame(struct ksignal * ksig,sigset_t * set,struct pt_regs * regs)966 static int setup_rt_frame(struct ksignal *ksig, sigset_t *set,
967 struct pt_regs *regs)
968 {
969 struct rt_sigframe __user *frame;
970 int fsize = frame_extra_sizes(regs->format);
971 int err = 0, sig = ksig->sig;
972
973 if (fsize < 0) {
974 pr_debug("setup_frame: Unknown frame format %#x\n",
975 regs->format);
976 return -EFAULT;
977 }
978
979 frame = get_sigframe(ksig, sizeof(*frame));
980
981 if (fsize)
982 err |= copy_to_user (&frame->uc.uc_extra, regs + 1, fsize);
983
984 err |= __put_user(sig, &frame->sig);
985 err |= __put_user(&frame->info, &frame->pinfo);
986 err |= __put_user(&frame->uc, &frame->puc);
987 err |= copy_siginfo_to_user(&frame->info, &ksig->info);
988
989 /* Create the ucontext. */
990 err |= __put_user(0, &frame->uc.uc_flags);
991 err |= __put_user(NULL, &frame->uc.uc_link);
992 err |= __save_altstack(&frame->uc.uc_stack, rdusp());
993 err |= rt_setup_ucontext(&frame->uc, regs);
994 err |= copy_to_user (&frame->uc.uc_sigmask, set, sizeof(*set));
995
996 /* Set up to return from userspace. */
997 #ifdef CONFIG_MMU
998 err |= __put_user(frame->retcode, &frame->pretcode);
999 #ifdef __mcoldfire__
1000 /* movel #__NR_rt_sigreturn,d0; trap #0 */
1001 err |= __put_user(0x203c0000, (long __user *)(frame->retcode + 0));
1002 err |= __put_user(0x00004e40 + (__NR_rt_sigreturn << 16),
1003 (long __user *)(frame->retcode + 4));
1004 #else
1005 /* moveq #,d0; notb d0; trap #0 */
1006 err |= __put_user(0x70004600 + ((__NR_rt_sigreturn ^ 0xff) << 16),
1007 (long __user *)(frame->retcode + 0));
1008 err |= __put_user(0x4e40, (short __user *)(frame->retcode + 4));
1009 #endif
1010 #else
1011 err |= __put_user((long) ret_from_user_rt_signal,
1012 (long __user *) &frame->pretcode);
1013 #endif /* CONFIG_MMU */
1014
1015 if (err)
1016 return -EFAULT;
1017
1018 push_cache ((unsigned long) &frame->retcode);
1019
1020 /*
1021 * Set up registers for signal handler. All the state we are about
1022 * to destroy is successfully copied to sigframe.
1023 */
1024 wrusp ((unsigned long) frame);
1025 regs->pc = (unsigned long) ksig->ka.sa.sa_handler;
1026 adjustformat(regs);
1027
1028 /*
1029 * This is subtle; if we build more than one sigframe, all but the
1030 * first one will see frame format 0 and have fsize == 0, so we won't
1031 * screw stkadj.
1032 */
1033 if (fsize)
1034 regs->stkadj = fsize;
1035
1036 /* Prepare to skip over the extra stuff in the exception frame. */
1037 if (regs->stkadj) {
1038 struct pt_regs *tregs =
1039 (struct pt_regs *)((ulong)regs + regs->stkadj);
1040 pr_debug("Performing stackadjust=%04lx\n", regs->stkadj);
1041 /* This must be copied with decreasing addresses to
1042 handle overlaps. */
1043 tregs->vector = 0;
1044 tregs->format = 0;
1045 tregs->pc = regs->pc;
1046 tregs->sr = regs->sr;
1047 }
1048 return 0;
1049 }
1050
1051 static inline void
handle_restart(struct pt_regs * regs,struct k_sigaction * ka,int has_handler)1052 handle_restart(struct pt_regs *regs, struct k_sigaction *ka, int has_handler)
1053 {
1054 switch (regs->d0) {
1055 case -ERESTARTNOHAND:
1056 if (!has_handler)
1057 goto do_restart;
1058 regs->d0 = -EINTR;
1059 break;
1060
1061 case -ERESTART_RESTARTBLOCK:
1062 if (!has_handler) {
1063 regs->d0 = __NR_restart_syscall;
1064 regs->pc -= 2;
1065 break;
1066 }
1067 regs->d0 = -EINTR;
1068 break;
1069
1070 case -ERESTARTSYS:
1071 if (has_handler && !(ka->sa.sa_flags & SA_RESTART)) {
1072 regs->d0 = -EINTR;
1073 break;
1074 }
1075 fallthrough;
1076 case -ERESTARTNOINTR:
1077 do_restart:
1078 regs->d0 = regs->orig_d0;
1079 regs->pc -= 2;
1080 break;
1081 }
1082 }
1083
1084 /*
1085 * OK, we're invoking a handler
1086 */
1087 static void
handle_signal(struct ksignal * ksig,struct pt_regs * regs)1088 handle_signal(struct ksignal *ksig, struct pt_regs *regs)
1089 {
1090 sigset_t *oldset = sigmask_to_save();
1091 int err;
1092 /* are we from a system call? */
1093 if (regs->orig_d0 >= 0)
1094 /* If so, check system call restarting.. */
1095 handle_restart(regs, &ksig->ka, 1);
1096
1097 /* set up the stack frame */
1098 if (ksig->ka.sa.sa_flags & SA_SIGINFO)
1099 err = setup_rt_frame(ksig, oldset, regs);
1100 else
1101 err = setup_frame(ksig, oldset, regs);
1102
1103 signal_setup_done(err, ksig, 0);
1104
1105 if (test_thread_flag(TIF_DELAYED_TRACE)) {
1106 regs->sr &= ~0x8000;
1107 send_sig(SIGTRAP, current, 1);
1108 }
1109 }
1110
1111 /*
1112 * Note that 'init' is a special process: it doesn't get signals it doesn't
1113 * want to handle. Thus you cannot kill init even with a SIGKILL even by
1114 * mistake.
1115 */
do_signal(struct pt_regs * regs)1116 static void do_signal(struct pt_regs *regs)
1117 {
1118 struct ksignal ksig;
1119
1120 current->thread.esp0 = (unsigned long) regs;
1121
1122 if (get_signal(&ksig)) {
1123 /* Whee! Actually deliver the signal. */
1124 handle_signal(&ksig, regs);
1125 return;
1126 }
1127
1128 /* Did we come from a system call? */
1129 if (regs->orig_d0 >= 0)
1130 /* Restart the system call - no handlers present */
1131 handle_restart(regs, NULL, 0);
1132
1133 /* If there's no signal to deliver, we just restore the saved mask. */
1134 restore_saved_sigmask();
1135 }
1136
do_notify_resume(struct pt_regs * regs)1137 void do_notify_resume(struct pt_regs *regs)
1138 {
1139 if (test_thread_flag(TIF_NOTIFY_SIGNAL) ||
1140 test_thread_flag(TIF_SIGPENDING))
1141 do_signal(regs);
1142
1143 if (test_thread_flag(TIF_NOTIFY_RESUME))
1144 tracehook_notify_resume(regs);
1145 }
1146