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/resume_user_mode.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#include "signal.h"
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_field(struct frame, un.fmt4)
67#endif
68
69static const int frame_size_change[16] = {
70 [1] = -1, /* sizeof_field(struct frame, un.fmt1), */
71 [2] = sizeof_field(struct frame, un.fmt2),
72 [3] = sizeof_field(struct frame, un.fmt3),
73 [4] = FMT4SIZE,
74 [5] = -1, /* sizeof_field(struct frame, un.fmt5), */
75 [6] = -1, /* sizeof_field(struct frame, un.fmt6), */
76 [7] = sizeof_field(struct frame, un.fmt7),
77 [8] = -1, /* sizeof_field(struct frame, un.fmt8), */
78 [9] = sizeof_field(struct frame, un.fmt9),
79 [10] = sizeof_field(struct frame, un.fmta),
80 [11] = sizeof_field(struct frame, un.fmtb),
81 [12] = -1, /* sizeof_field(struct frame, un.fmtc), */
82 [13] = -1, /* sizeof_field(struct frame, un.fmtd), */
83 [14] = -1, /* sizeof_field(struct frame, un.fmte), */
84 [15] = -1, /* sizeof_field(struct frame, un.fmtf), */
85};
86
87static inline int frame_extra_sizes(int f)
88{
89 return frame_size_change[f];
90}
91
92int fixup_exception(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(add: 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(f: 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
113static inline void push_cache (unsigned long vaddr)
114{
115 /*
116 * Using the old cache_push_v() was really a big waste.
117 *
118 * What we are trying to do is to flush 8 bytes to ram.
119 * Flushing 2 cache lines of 16 bytes is much cheaper than
120 * flushing 1 or 2 pages, as previously done in
121 * cache_push_v().
122 * Jes
123 */
124 if (CPU_IS_040) {
125 unsigned long temp;
126
127 __asm__ __volatile__ (".chip 68040\n\t"
128 "nop\n\t"
129 "ptestr (%1)\n\t"
130 "movec %%mmusr,%0\n\t"
131 ".chip 68k"
132 : "=r" (temp)
133 : "a" (vaddr));
134
135 temp &= PAGE_MASK;
136 temp |= vaddr & ~PAGE_MASK;
137
138 __asm__ __volatile__ (".chip 68040\n\t"
139 "nop\n\t"
140 "cpushl %%bc,(%0)\n\t"
141 ".chip 68k"
142 : : "a" (temp));
143 }
144 else if (CPU_IS_060) {
145 unsigned long temp;
146 __asm__ __volatile__ (".chip 68060\n\t"
147 "plpar (%0)\n\t"
148 ".chip 68k"
149 : "=a" (temp)
150 : "0" (vaddr));
151 __asm__ __volatile__ (".chip 68060\n\t"
152 "cpushl %%bc,(%0)\n\t"
153 ".chip 68k"
154 : : "a" (temp));
155 } else if (!CPU_IS_COLDFIRE) {
156 /*
157 * 68030/68020 have no writeback cache;
158 * still need to clear icache.
159 * Note that vaddr is guaranteed to be long word aligned.
160 */
161 unsigned long temp;
162 asm volatile ("movec %%cacr,%0" : "=r" (temp));
163 temp += 4;
164 asm volatile ("movec %0,%%caar\n\t"
165 "movec %1,%%cacr"
166 : : "r" (vaddr), "r" (temp));
167 asm volatile ("movec %0,%%caar\n\t"
168 "movec %1,%%cacr"
169 : : "r" (vaddr + 4), "r" (temp));
170 } else {
171 /* CPU_IS_COLDFIRE */
172#if defined(CONFIG_CACHE_COPYBACK)
173 flush_cf_dcache(0, DCACHE_MAX_ADDR);
174#endif
175 /* Invalidate instruction cache for the pushed bytes */
176 clear_cf_icache(vaddr, vaddr + 8);
177 }
178}
179
180static inline void adjustformat(struct pt_regs *regs)
181{
182}
183
184static inline void save_a5_state(struct sigcontext *sc, struct pt_regs *regs)
185{
186}
187
188#else /* CONFIG_MMU */
189
190void ret_from_user_signal(void);
191void ret_from_user_rt_signal(void);
192
193static inline int frame_extra_sizes(int f)
194{
195 /* No frame size adjustments required on non-MMU CPUs */
196 return 0;
197}
198
199static inline void adjustformat(struct pt_regs *regs)
200{
201 /*
202 * set format byte to make stack appear modulo 4, which it will
203 * be when doing the rte
204 */
205 regs->format = 0x4;
206}
207
208static inline void save_a5_state(struct sigcontext *sc, struct pt_regs *regs)
209{
210 sc->sc_a5 = ((struct switch_stack *)regs - 1)->a5;
211}
212
213static inline void push_cache(unsigned long vaddr)
214{
215}
216
217#endif /* CONFIG_MMU */
218
219/*
220 * Do a signal return; undo the signal stack.
221 *
222 * Keep the return code on the stack quadword aligned!
223 * That makes the cache flush below easier.
224 */
225
226struct sigframe
227{
228 char __user *pretcode;
229 int sig;
230 int code;
231 struct sigcontext __user *psc;
232 char retcode[8];
233 unsigned long extramask[_NSIG_WORDS-1];
234 struct sigcontext sc;
235};
236
237struct rt_sigframe
238{
239 char __user *pretcode;
240 int sig;
241 struct siginfo __user *pinfo;
242 void __user *puc;
243 char retcode[8];
244 struct siginfo info;
245 struct ucontext uc;
246};
247
248#define FPCONTEXT_SIZE 216
249#define uc_fpstate uc_filler[0]
250#define uc_formatvec uc_filler[FPCONTEXT_SIZE/4]
251#define uc_extra uc_filler[FPCONTEXT_SIZE/4+1]
252
253#ifdef CONFIG_FPU
254
255static unsigned char fpu_version; /* version number of fpu, set by setup_frame */
256
257static inline int restore_fpu_state(struct sigcontext *sc)
258{
259 int err = 1;
260
261 if (FPU_IS_EMU) {
262 /* restore registers */
263 memcpy(current->thread.fpcntl, sc->sc_fpcntl, 12);
264 memcpy(current->thread.fp, sc->sc_fpregs, 24);
265 return 0;
266 }
267
268 if (CPU_IS_060 ? sc->sc_fpstate[2] : sc->sc_fpstate[0]) {
269 /* Verify the frame format. */
270 if (!(CPU_IS_060 || CPU_IS_COLDFIRE) &&
271 (sc->sc_fpstate[0] != fpu_version))
272 goto out;
273 if (CPU_IS_020_OR_030) {
274 if (m68k_fputype & FPU_68881 &&
275 !(sc->sc_fpstate[1] == 0x18 || sc->sc_fpstate[1] == 0xb4))
276 goto out;
277 if (m68k_fputype & FPU_68882 &&
278 !(sc->sc_fpstate[1] == 0x38 || sc->sc_fpstate[1] == 0xd4))
279 goto out;
280 } else if (CPU_IS_040) {
281 if (!(sc->sc_fpstate[1] == 0x00 ||
282 sc->sc_fpstate[1] == 0x28 ||
283 sc->sc_fpstate[1] == 0x60))
284 goto out;
285 } else if (CPU_IS_060) {
286 if (!(sc->sc_fpstate[3] == 0x00 ||
287 sc->sc_fpstate[3] == 0x60 ||
288 sc->sc_fpstate[3] == 0xe0))
289 goto out;
290 } else if (CPU_IS_COLDFIRE) {
291 if (!(sc->sc_fpstate[0] == 0x00 ||
292 sc->sc_fpstate[0] == 0x05 ||
293 sc->sc_fpstate[0] == 0xe5))
294 goto out;
295 } else
296 goto out;
297
298 if (CPU_IS_COLDFIRE) {
299 __asm__ volatile ("fmovemd %0,%%fp0-%%fp1\n\t"
300 "fmovel %1,%%fpcr\n\t"
301 "fmovel %2,%%fpsr\n\t"
302 "fmovel %3,%%fpiar"
303 : /* no outputs */
304 : "m" (sc->sc_fpregs[0]),
305 "m" (sc->sc_fpcntl[0]),
306 "m" (sc->sc_fpcntl[1]),
307 "m" (sc->sc_fpcntl[2]));
308 } else {
309 __asm__ volatile (".chip 68k/68881\n\t"
310 "fmovemx %0,%%fp0-%%fp1\n\t"
311 "fmoveml %1,%%fpcr/%%fpsr/%%fpiar\n\t"
312 ".chip 68k"
313 : /* no outputs */
314 : "m" (*sc->sc_fpregs),
315 "m" (*sc->sc_fpcntl));
316 }
317 }
318
319 if (CPU_IS_COLDFIRE) {
320 __asm__ volatile ("frestore %0" : : "m" (*sc->sc_fpstate));
321 } else {
322 __asm__ volatile (".chip 68k/68881\n\t"
323 "frestore %0\n\t"
324 ".chip 68k"
325 : : "m" (*sc->sc_fpstate));
326 }
327 err = 0;
328
329out:
330 return err;
331}
332
333static inline int rt_restore_fpu_state(struct ucontext __user *uc)
334{
335 unsigned char fpstate[FPCONTEXT_SIZE];
336 int context_size = CPU_IS_060 ? 8 : (CPU_IS_COLDFIRE ? 12 : 0);
337 fpregset_t fpregs;
338 int err = 1;
339
340 if (FPU_IS_EMU) {
341 /* restore fpu control register */
342 if (__copy_from_user(current->thread.fpcntl,
343 uc->uc_mcontext.fpregs.f_fpcntl, 12))
344 goto out;
345 /* restore all other fpu register */
346 if (__copy_from_user(current->thread.fp,
347 uc->uc_mcontext.fpregs.f_fpregs, 96))
348 goto out;
349 return 0;
350 }
351
352 if (__get_user(*(long *)fpstate, (long __user *)&uc->uc_fpstate))
353 goto out;
354 if (CPU_IS_060 ? fpstate[2] : fpstate[0]) {
355 if (!(CPU_IS_060 || CPU_IS_COLDFIRE))
356 context_size = fpstate[1];
357 /* Verify the frame format. */
358 if (!(CPU_IS_060 || CPU_IS_COLDFIRE) &&
359 (fpstate[0] != fpu_version))
360 goto out;
361 if (CPU_IS_020_OR_030) {
362 if (m68k_fputype & FPU_68881 &&
363 !(context_size == 0x18 || context_size == 0xb4))
364 goto out;
365 if (m68k_fputype & FPU_68882 &&
366 !(context_size == 0x38 || context_size == 0xd4))
367 goto out;
368 } else if (CPU_IS_040) {
369 if (!(context_size == 0x00 ||
370 context_size == 0x28 ||
371 context_size == 0x60))
372 goto out;
373 } else if (CPU_IS_060) {
374 if (!(fpstate[3] == 0x00 ||
375 fpstate[3] == 0x60 ||
376 fpstate[3] == 0xe0))
377 goto out;
378 } else if (CPU_IS_COLDFIRE) {
379 if (!(fpstate[3] == 0x00 ||
380 fpstate[3] == 0x05 ||
381 fpstate[3] == 0xe5))
382 goto out;
383 } else
384 goto out;
385 if (__copy_from_user(&fpregs, &uc->uc_mcontext.fpregs,
386 sizeof(fpregs)))
387 goto out;
388
389 if (CPU_IS_COLDFIRE) {
390 __asm__ volatile ("fmovemd %0,%%fp0-%%fp7\n\t"
391 "fmovel %1,%%fpcr\n\t"
392 "fmovel %2,%%fpsr\n\t"
393 "fmovel %3,%%fpiar"
394 : /* no outputs */
395 : "m" (fpregs.f_fpregs[0]),
396 "m" (fpregs.f_fpcntl[0]),
397 "m" (fpregs.f_fpcntl[1]),
398 "m" (fpregs.f_fpcntl[2]));
399 } else {
400 __asm__ volatile (".chip 68k/68881\n\t"
401 "fmovemx %0,%%fp0-%%fp7\n\t"
402 "fmoveml %1,%%fpcr/%%fpsr/%%fpiar\n\t"
403 ".chip 68k"
404 : /* no outputs */
405 : "m" (*fpregs.f_fpregs),
406 "m" (*fpregs.f_fpcntl));
407 }
408 }
409 if (context_size &&
410 __copy_from_user(fpstate + 4, (long __user *)&uc->uc_fpstate + 1,
411 context_size))
412 goto out;
413
414 if (CPU_IS_COLDFIRE) {
415 __asm__ volatile ("frestore %0" : : "m" (*fpstate));
416 } else {
417 __asm__ volatile (".chip 68k/68881\n\t"
418 "frestore %0\n\t"
419 ".chip 68k"
420 : : "m" (*fpstate));
421 }
422 err = 0;
423
424out:
425 return err;
426}
427
428/*
429 * Set up a signal frame.
430 */
431static inline void save_fpu_state(struct sigcontext *sc, struct pt_regs *regs)
432{
433 if (FPU_IS_EMU) {
434 /* save registers */
435 memcpy(sc->sc_fpcntl, current->thread.fpcntl, 12);
436 memcpy(sc->sc_fpregs, current->thread.fp, 24);
437 return;
438 }
439
440 if (CPU_IS_COLDFIRE) {
441 __asm__ volatile ("fsave %0"
442 : : "m" (*sc->sc_fpstate) : "memory");
443 } else {
444 __asm__ volatile (".chip 68k/68881\n\t"
445 "fsave %0\n\t"
446 ".chip 68k"
447 : : "m" (*sc->sc_fpstate) : "memory");
448 }
449
450 if (CPU_IS_060 ? sc->sc_fpstate[2] : sc->sc_fpstate[0]) {
451 fpu_version = sc->sc_fpstate[0];
452 if (CPU_IS_020_OR_030 && !regs->stkadj &&
453 regs->vector >= (VEC_FPBRUC * 4) &&
454 regs->vector <= (VEC_FPNAN * 4)) {
455 /* Clear pending exception in 68882 idle frame */
456 if (*(unsigned short *) sc->sc_fpstate == 0x1f38)
457 sc->sc_fpstate[0x38] |= 1 << 3;
458 }
459
460 if (CPU_IS_COLDFIRE) {
461 __asm__ volatile ("fmovemd %%fp0-%%fp1,%0\n\t"
462 "fmovel %%fpcr,%1\n\t"
463 "fmovel %%fpsr,%2\n\t"
464 "fmovel %%fpiar,%3"
465 : "=m" (sc->sc_fpregs[0]),
466 "=m" (sc->sc_fpcntl[0]),
467 "=m" (sc->sc_fpcntl[1]),
468 "=m" (sc->sc_fpcntl[2])
469 : /* no inputs */
470 : "memory");
471 } else {
472 __asm__ volatile (".chip 68k/68881\n\t"
473 "fmovemx %%fp0-%%fp1,%0\n\t"
474 "fmoveml %%fpcr/%%fpsr/%%fpiar,%1\n\t"
475 ".chip 68k"
476 : "=m" (*sc->sc_fpregs),
477 "=m" (*sc->sc_fpcntl)
478 : /* no inputs */
479 : "memory");
480 }
481 }
482}
483
484static inline int rt_save_fpu_state(struct ucontext __user *uc, struct pt_regs *regs)
485{
486 unsigned char fpstate[FPCONTEXT_SIZE];
487 int context_size = CPU_IS_060 ? 8 : (CPU_IS_COLDFIRE ? 12 : 0);
488 int err = 0;
489
490 if (FPU_IS_EMU) {
491 /* save fpu control register */
492 err |= copy_to_user(uc->uc_mcontext.fpregs.f_fpcntl,
493 current->thread.fpcntl, 12);
494 /* save all other fpu register */
495 err |= copy_to_user(uc->uc_mcontext.fpregs.f_fpregs,
496 current->thread.fp, 96);
497 return err;
498 }
499
500 if (CPU_IS_COLDFIRE) {
501 __asm__ volatile ("fsave %0" : : "m" (*fpstate) : "memory");
502 } else {
503 __asm__ volatile (".chip 68k/68881\n\t"
504 "fsave %0\n\t"
505 ".chip 68k"
506 : : "m" (*fpstate) : "memory");
507 }
508
509 err |= __put_user(*(long *)fpstate, (long __user *)&uc->uc_fpstate);
510 if (CPU_IS_060 ? fpstate[2] : fpstate[0]) {
511 fpregset_t fpregs;
512 if (!(CPU_IS_060 || CPU_IS_COLDFIRE))
513 context_size = fpstate[1];
514 fpu_version = fpstate[0];
515 if (CPU_IS_020_OR_030 && !regs->stkadj &&
516 regs->vector >= (VEC_FPBRUC * 4) &&
517 regs->vector <= (VEC_FPNAN * 4)) {
518 /* Clear pending exception in 68882 idle frame */
519 if (*(unsigned short *) fpstate == 0x1f38)
520 fpstate[0x38] |= 1 << 3;
521 }
522 if (CPU_IS_COLDFIRE) {
523 __asm__ volatile ("fmovemd %%fp0-%%fp7,%0\n\t"
524 "fmovel %%fpcr,%1\n\t"
525 "fmovel %%fpsr,%2\n\t"
526 "fmovel %%fpiar,%3"
527 : "=m" (fpregs.f_fpregs[0]),
528 "=m" (fpregs.f_fpcntl[0]),
529 "=m" (fpregs.f_fpcntl[1]),
530 "=m" (fpregs.f_fpcntl[2])
531 : /* no inputs */
532 : "memory");
533 } else {
534 __asm__ volatile (".chip 68k/68881\n\t"
535 "fmovemx %%fp0-%%fp7,%0\n\t"
536 "fmoveml %%fpcr/%%fpsr/%%fpiar,%1\n\t"
537 ".chip 68k"
538 : "=m" (*fpregs.f_fpregs),
539 "=m" (*fpregs.f_fpcntl)
540 : /* no inputs */
541 : "memory");
542 }
543 err |= copy_to_user(&uc->uc_mcontext.fpregs, &fpregs,
544 sizeof(fpregs));
545 }
546 if (context_size)
547 err |= copy_to_user((long __user *)&uc->uc_fpstate + 1, fpstate + 4,
548 context_size);
549 return err;
550}
551
552#else /* CONFIG_FPU */
553
554/*
555 * For the case with no FPU configured these all do nothing.
556 */
557static inline int restore_fpu_state(struct sigcontext *sc)
558{
559 return 0;
560}
561
562static inline int rt_restore_fpu_state(struct ucontext __user *uc)
563{
564 return 0;
565}
566
567static inline void save_fpu_state(struct sigcontext *sc, struct pt_regs *regs)
568{
569}
570
571static inline int rt_save_fpu_state(struct ucontext __user *uc, struct pt_regs *regs)
572{
573 return 0;
574}
575
576#endif /* CONFIG_FPU */
577
578static inline void siginfo_build_tests(void)
579{
580 /*
581 * This needs to be tested on m68k as it has a lesser
582 * alignment requirement than x86 and that can cause surprises.
583 */
584
585 /* This is part of the ABI and can never change in size: */
586 BUILD_BUG_ON(sizeof(siginfo_t) != 128);
587
588 /* Ensure the known fields never change in location */
589 BUILD_BUG_ON(offsetof(siginfo_t, si_signo) != 0);
590 BUILD_BUG_ON(offsetof(siginfo_t, si_errno) != 4);
591 BUILD_BUG_ON(offsetof(siginfo_t, si_code) != 8);
592
593 /* _kill */
594 BUILD_BUG_ON(offsetof(siginfo_t, si_pid) != 0x0c);
595 BUILD_BUG_ON(offsetof(siginfo_t, si_uid) != 0x10);
596
597 /* _timer */
598 BUILD_BUG_ON(offsetof(siginfo_t, si_tid) != 0x0c);
599 BUILD_BUG_ON(offsetof(siginfo_t, si_overrun) != 0x10);
600 BUILD_BUG_ON(offsetof(siginfo_t, si_value) != 0x14);
601
602 /* _rt */
603 BUILD_BUG_ON(offsetof(siginfo_t, si_pid) != 0x0c);
604 BUILD_BUG_ON(offsetof(siginfo_t, si_uid) != 0x10);
605 BUILD_BUG_ON(offsetof(siginfo_t, si_value) != 0x14);
606
607 /* _sigchld */
608 BUILD_BUG_ON(offsetof(siginfo_t, si_pid) != 0x0c);
609 BUILD_BUG_ON(offsetof(siginfo_t, si_uid) != 0x10);
610 BUILD_BUG_ON(offsetof(siginfo_t, si_status) != 0x14);
611 BUILD_BUG_ON(offsetof(siginfo_t, si_utime) != 0x18);
612 BUILD_BUG_ON(offsetof(siginfo_t, si_stime) != 0x1c);
613
614 /* _sigfault */
615 BUILD_BUG_ON(offsetof(siginfo_t, si_addr) != 0x0c);
616
617 /* _sigfault._mcerr */
618 BUILD_BUG_ON(offsetof(siginfo_t, si_addr_lsb) != 0x10);
619
620 /* _sigfault._addr_bnd */
621 BUILD_BUG_ON(offsetof(siginfo_t, si_lower) != 0x12);
622 BUILD_BUG_ON(offsetof(siginfo_t, si_upper) != 0x16);
623
624 /* _sigfault._addr_pkey */
625 BUILD_BUG_ON(offsetof(siginfo_t, si_pkey) != 0x12);
626
627 /* _sigfault._perf */
628 BUILD_BUG_ON(offsetof(siginfo_t, si_perf_data) != 0x10);
629 BUILD_BUG_ON(offsetof(siginfo_t, si_perf_type) != 0x14);
630 BUILD_BUG_ON(offsetof(siginfo_t, si_perf_flags) != 0x18);
631
632 /* _sigpoll */
633 BUILD_BUG_ON(offsetof(siginfo_t, si_band) != 0x0c);
634 BUILD_BUG_ON(offsetof(siginfo_t, si_fd) != 0x10);
635
636 /* _sigsys */
637 BUILD_BUG_ON(offsetof(siginfo_t, si_call_addr) != 0x0c);
638 BUILD_BUG_ON(offsetof(siginfo_t, si_syscall) != 0x10);
639 BUILD_BUG_ON(offsetof(siginfo_t, si_arch) != 0x14);
640
641 /* any new si_fields should be added here */
642}
643
644static int mangle_kernel_stack(struct pt_regs *regs, int formatvec,
645 void __user *fp)
646{
647 int extra = frame_extra_sizes(f: formatvec >> 12);
648 char buf[sizeof_field(struct frame, un)];
649
650 if (extra < 0) {
651 /*
652 * user process trying to return with weird frame format
653 */
654 pr_debug("user process returning with weird frame format\n");
655 return -1;
656 }
657 if (extra && copy_from_user(to: buf, from: fp, n: extra))
658 return -1;
659 regs->format = formatvec >> 12;
660 regs->vector = formatvec & 0xfff;
661 if (extra) {
662 void *p = (struct switch_stack *)regs - 1;
663 struct frame *new = (void *)regs - extra;
664 int size = sizeof(struct pt_regs)+sizeof(struct switch_stack);
665
666 memmove(p - extra, p, size);
667 memcpy(p - extra + size, buf, extra);
668 current->thread.esp0 = (unsigned long)&new->ptregs;
669#ifdef CONFIG_M68040
670 /* on 68040 complete pending writebacks if any */
671 if (new->ptregs.format == 7) // bus error frame
672 berr_040cleanup(new);
673#endif
674 }
675 return extra;
676}
677
678static inline int
679restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *usc, void __user *fp)
680{
681 int formatvec;
682 struct sigcontext context;
683
684 siginfo_build_tests();
685
686 /* Always make any pending restarted system calls return -EINTR */
687 current->restart_block.fn = do_no_restart_syscall;
688
689 /* get previous context */
690 if (copy_from_user(to: &context, from: usc, n: sizeof(context)))
691 return -1;
692
693 /* restore passed registers */
694 regs->d0 = context.sc_d0;
695 regs->d1 = context.sc_d1;
696 regs->a0 = context.sc_a0;
697 regs->a1 = context.sc_a1;
698 regs->sr = (regs->sr & 0xff00) | (context.sc_sr & 0xff);
699 regs->pc = context.sc_pc;
700 regs->orig_d0 = -1; /* disable syscall checks */
701 wrusp(context.sc_usp);
702 formatvec = context.sc_formatvec;
703
704 if (restore_fpu_state(sc: &context))
705 return -1;
706
707 return mangle_kernel_stack(regs, formatvec, fp);
708}
709
710static inline int
711rt_restore_ucontext(struct pt_regs *regs, struct switch_stack *sw,
712 struct ucontext __user *uc)
713{
714 int temp;
715 greg_t __user *gregs = uc->uc_mcontext.gregs;
716 unsigned long usp;
717 int err;
718
719 /* Always make any pending restarted system calls return -EINTR */
720 current->restart_block.fn = do_no_restart_syscall;
721
722 err = __get_user(temp, &uc->uc_mcontext.version);
723 if (temp != MCONTEXT_VERSION)
724 return -1;
725 /* restore passed registers */
726 err |= __get_user(regs->d0, &gregs[0]);
727 err |= __get_user(regs->d1, &gregs[1]);
728 err |= __get_user(regs->d2, &gregs[2]);
729 err |= __get_user(regs->d3, &gregs[3]);
730 err |= __get_user(regs->d4, &gregs[4]);
731 err |= __get_user(regs->d5, &gregs[5]);
732 err |= __get_user(sw->d6, &gregs[6]);
733 err |= __get_user(sw->d7, &gregs[7]);
734 err |= __get_user(regs->a0, &gregs[8]);
735 err |= __get_user(regs->a1, &gregs[9]);
736 err |= __get_user(regs->a2, &gregs[10]);
737 err |= __get_user(sw->a3, &gregs[11]);
738 err |= __get_user(sw->a4, &gregs[12]);
739 err |= __get_user(sw->a5, &gregs[13]);
740 err |= __get_user(sw->a6, &gregs[14]);
741 err |= __get_user(usp, &gregs[15]);
742 wrusp(usp);
743 err |= __get_user(regs->pc, &gregs[16]);
744 err |= __get_user(temp, &gregs[17]);
745 regs->sr = (regs->sr & 0xff00) | (temp & 0xff);
746 regs->orig_d0 = -1; /* disable syscall checks */
747 err |= __get_user(temp, &uc->uc_formatvec);
748
749 err |= rt_restore_fpu_state(uc);
750 err |= restore_altstack(&uc->uc_stack);
751
752 if (err)
753 return -1;
754
755 return mangle_kernel_stack(regs, formatvec: temp, fp: &uc->uc_extra);
756}
757
758asmlinkage void *do_sigreturn(struct pt_regs *regs, struct switch_stack *sw)
759{
760 unsigned long usp = rdusp();
761 struct sigframe __user *frame = (struct sigframe __user *)(usp - 4);
762 sigset_t set;
763 int size;
764
765 if (!access_ok(frame, sizeof(*frame)))
766 goto badframe;
767 if (__get_user(set.sig[0], &frame->sc.sc_mask) ||
768 (_NSIG_WORDS > 1 &&
769 __copy_from_user(to: &set.sig[1], from: &frame->extramask,
770 n: sizeof(frame->extramask))))
771 goto badframe;
772
773 set_current_blocked(&set);
774
775 size = restore_sigcontext(regs, usc: &frame->sc, fp: frame + 1);
776 if (size < 0)
777 goto badframe;
778 return (void *)sw - size;
779
780badframe:
781 force_sig(SIGSEGV);
782 return sw;
783}
784
785asmlinkage void *do_rt_sigreturn(struct pt_regs *regs, struct switch_stack *sw)
786{
787 unsigned long usp = rdusp();
788 struct rt_sigframe __user *frame = (struct rt_sigframe __user *)(usp - 4);
789 sigset_t set;
790 int size;
791
792 if (!access_ok(frame, sizeof(*frame)))
793 goto badframe;
794 if (__copy_from_user(to: &set, from: &frame->uc.uc_sigmask, n: sizeof(set)))
795 goto badframe;
796
797 set_current_blocked(&set);
798
799 size = rt_restore_ucontext(regs, sw, uc: &frame->uc);
800 if (size < 0)
801 goto badframe;
802 return (void *)sw - size;
803
804badframe:
805 force_sig(SIGSEGV);
806 return sw;
807}
808
809static inline struct pt_regs *rte_regs(struct pt_regs *regs)
810{
811 return (void *)regs + regs->stkadj;
812}
813
814static void setup_sigcontext(struct sigcontext *sc, struct pt_regs *regs,
815 unsigned long mask)
816{
817 struct pt_regs *tregs = rte_regs(regs);
818 sc->sc_mask = mask;
819 sc->sc_usp = rdusp();
820 sc->sc_d0 = regs->d0;
821 sc->sc_d1 = regs->d1;
822 sc->sc_a0 = regs->a0;
823 sc->sc_a1 = regs->a1;
824 sc->sc_sr = tregs->sr;
825 sc->sc_pc = tregs->pc;
826 sc->sc_formatvec = tregs->format << 12 | tregs->vector;
827 save_a5_state(sc, regs);
828 save_fpu_state(sc, regs);
829}
830
831static inline int rt_setup_ucontext(struct ucontext __user *uc, struct pt_regs *regs)
832{
833 struct switch_stack *sw = (struct switch_stack *)regs - 1;
834 struct pt_regs *tregs = rte_regs(regs);
835 greg_t __user *gregs = uc->uc_mcontext.gregs;
836 int err = 0;
837
838 err |= __put_user(MCONTEXT_VERSION, &uc->uc_mcontext.version);
839 err |= __put_user(regs->d0, &gregs[0]);
840 err |= __put_user(regs->d1, &gregs[1]);
841 err |= __put_user(regs->d2, &gregs[2]);
842 err |= __put_user(regs->d3, &gregs[3]);
843 err |= __put_user(regs->d4, &gregs[4]);
844 err |= __put_user(regs->d5, &gregs[5]);
845 err |= __put_user(sw->d6, &gregs[6]);
846 err |= __put_user(sw->d7, &gregs[7]);
847 err |= __put_user(regs->a0, &gregs[8]);
848 err |= __put_user(regs->a1, &gregs[9]);
849 err |= __put_user(regs->a2, &gregs[10]);
850 err |= __put_user(sw->a3, &gregs[11]);
851 err |= __put_user(sw->a4, &gregs[12]);
852 err |= __put_user(sw->a5, &gregs[13]);
853 err |= __put_user(sw->a6, &gregs[14]);
854 err |= __put_user(rdusp(), &gregs[15]);
855 err |= __put_user(tregs->pc, &gregs[16]);
856 err |= __put_user(tregs->sr, &gregs[17]);
857 err |= __put_user((tregs->format << 12) | tregs->vector, &uc->uc_formatvec);
858 err |= rt_save_fpu_state(uc, regs);
859 return err;
860}
861
862static inline void __user *
863get_sigframe(struct ksignal *ksig, struct pt_regs *tregs, size_t frame_size)
864{
865 unsigned long usp = sigsp(sp: rdusp(), ksig);
866 unsigned long gap = 0;
867
868 if (CPU_IS_020_OR_030 && tregs->format == 0xb) {
869 /* USP is unreliable so use worst-case value */
870 gap = 256;
871 }
872
873 return (void __user *)((usp - gap - frame_size) & -8UL);
874}
875
876static int setup_frame(struct ksignal *ksig, sigset_t *set,
877 struct pt_regs *regs)
878{
879 struct sigframe __user *frame;
880 struct pt_regs *tregs = rte_regs(regs);
881 int fsize = frame_extra_sizes(f: tregs->format);
882 struct sigcontext context;
883 int err = 0, sig = ksig->sig;
884
885 if (fsize < 0) {
886 pr_debug("setup_frame: Unknown frame format %#x\n",
887 tregs->format);
888 return -EFAULT;
889 }
890
891 frame = get_sigframe(ksig, tregs, frame_size: sizeof(*frame) + fsize);
892
893 if (fsize)
894 err |= copy_to_user (to: frame + 1, from: regs + 1, n: fsize);
895
896 err |= __put_user(sig, &frame->sig);
897
898 err |= __put_user(tregs->vector, &frame->code);
899 err |= __put_user(&frame->sc, &frame->psc);
900
901 if (_NSIG_WORDS > 1)
902 err |= copy_to_user(to: frame->extramask, from: &set->sig[1],
903 n: sizeof(frame->extramask));
904
905 setup_sigcontext(sc: &context, regs, mask: set->sig[0]);
906 err |= copy_to_user (to: &frame->sc, from: &context, n: sizeof(context));
907
908 /* Set up to return from userspace. */
909#ifdef CONFIG_MMU
910 err |= __put_user(frame->retcode, &frame->pretcode);
911 /* moveq #,d0; trap #0 */
912 err |= __put_user(0x70004e40 + (__NR_sigreturn << 16),
913 (long __user *)(frame->retcode));
914#else
915 err |= __put_user((long) ret_from_user_signal,
916 (long __user *) &frame->pretcode);
917#endif
918
919 if (err)
920 return -EFAULT;
921
922 push_cache (vaddr: (unsigned long) &frame->retcode);
923
924 /*
925 * This is subtle; if we build more than one sigframe, all but the
926 * first one will see frame format 0 and have fsize == 0, so we won't
927 * screw stkadj.
928 */
929 if (fsize) {
930 regs->stkadj = fsize;
931 tregs = rte_regs(regs);
932 pr_debug("Performing stackadjust=%04lx\n", regs->stkadj);
933 tregs->vector = 0;
934 tregs->format = 0;
935 tregs->sr = regs->sr;
936 }
937
938 /*
939 * Set up registers for signal handler. All the state we are about
940 * to destroy is successfully copied to sigframe.
941 */
942 wrusp ((unsigned long) frame);
943 tregs->pc = (unsigned long) ksig->ka.sa.sa_handler;
944 adjustformat(regs);
945
946 return 0;
947}
948
949static int setup_rt_frame(struct ksignal *ksig, sigset_t *set,
950 struct pt_regs *regs)
951{
952 struct rt_sigframe __user *frame;
953 struct pt_regs *tregs = rte_regs(regs);
954 int fsize = frame_extra_sizes(f: tregs->format);
955 int err = 0, sig = ksig->sig;
956
957 if (fsize < 0) {
958 pr_debug("setup_frame: Unknown frame format %#x\n",
959 regs->format);
960 return -EFAULT;
961 }
962
963 frame = get_sigframe(ksig, tregs, frame_size: sizeof(*frame));
964
965 if (fsize)
966 err |= copy_to_user (to: &frame->uc.uc_extra, from: regs + 1, n: fsize);
967
968 err |= __put_user(sig, &frame->sig);
969 err |= __put_user(&frame->info, &frame->pinfo);
970 err |= __put_user(&frame->uc, &frame->puc);
971 err |= copy_siginfo_to_user(to: &frame->info, from: &ksig->info);
972
973 /* Create the ucontext. */
974 err |= __put_user(0, &frame->uc.uc_flags);
975 err |= __put_user(NULL, &frame->uc.uc_link);
976 err |= __save_altstack(&frame->uc.uc_stack, rdusp());
977 err |= rt_setup_ucontext(uc: &frame->uc, regs);
978 err |= copy_to_user (to: &frame->uc.uc_sigmask, from: set, n: sizeof(*set));
979
980 /* Set up to return from userspace. */
981#ifdef CONFIG_MMU
982 err |= __put_user(frame->retcode, &frame->pretcode);
983#ifdef __mcoldfire__
984 /* movel #__NR_rt_sigreturn,d0; trap #0 */
985 err |= __put_user(0x203c0000, (long __user *)(frame->retcode + 0));
986 err |= __put_user(0x00004e40 + (__NR_rt_sigreturn << 16),
987 (long __user *)(frame->retcode + 4));
988#else
989 /* moveq #,d0; notb d0; trap #0 */
990 err |= __put_user(0x70004600 + ((__NR_rt_sigreturn ^ 0xff) << 16),
991 (long __user *)(frame->retcode + 0));
992 err |= __put_user(0x4e40, (short __user *)(frame->retcode + 4));
993#endif
994#else
995 err |= __put_user((long) ret_from_user_rt_signal,
996 (long __user *) &frame->pretcode);
997#endif /* CONFIG_MMU */
998
999 if (err)
1000 return -EFAULT;
1001
1002 push_cache (vaddr: (unsigned long) &frame->retcode);
1003
1004 /*
1005 * This is subtle; if we build more than one sigframe, all but the
1006 * first one will see frame format 0 and have fsize == 0, so we won't
1007 * screw stkadj.
1008 */
1009 if (fsize) {
1010 regs->stkadj = fsize;
1011 tregs = rte_regs(regs);
1012 pr_debug("Performing stackadjust=%04lx\n", regs->stkadj);
1013 tregs->vector = 0;
1014 tregs->format = 0;
1015 tregs->sr = regs->sr;
1016 }
1017
1018 /*
1019 * Set up registers for signal handler. All the state we are about
1020 * to destroy is successfully copied to sigframe.
1021 */
1022 wrusp ((unsigned long) frame);
1023 tregs->pc = (unsigned long) ksig->ka.sa.sa_handler;
1024 adjustformat(regs);
1025 return 0;
1026}
1027
1028static inline void
1029handle_restart(struct pt_regs *regs, struct k_sigaction *ka, int has_handler)
1030{
1031 switch (regs->d0) {
1032 case -ERESTARTNOHAND:
1033 if (!has_handler)
1034 goto do_restart;
1035 regs->d0 = -EINTR;
1036 break;
1037
1038 case -ERESTART_RESTARTBLOCK:
1039 if (!has_handler) {
1040 regs->d0 = __NR_restart_syscall;
1041 regs->pc -= 2;
1042 break;
1043 }
1044 regs->d0 = -EINTR;
1045 break;
1046
1047 case -ERESTARTSYS:
1048 if (has_handler && !(ka->sa.sa_flags & SA_RESTART)) {
1049 regs->d0 = -EINTR;
1050 break;
1051 }
1052 fallthrough;
1053 case -ERESTARTNOINTR:
1054 do_restart:
1055 regs->d0 = regs->orig_d0;
1056 regs->pc -= 2;
1057 break;
1058 }
1059}
1060
1061/*
1062 * OK, we're invoking a handler
1063 */
1064static void
1065handle_signal(struct ksignal *ksig, struct pt_regs *regs)
1066{
1067 sigset_t *oldset = sigmask_to_save();
1068 int err;
1069 /* are we from a system call? */
1070 if (regs->orig_d0 >= 0)
1071 /* If so, check system call restarting.. */
1072 handle_restart(regs, ka: &ksig->ka, has_handler: 1);
1073
1074 /* set up the stack frame */
1075 if (ksig->ka.sa.sa_flags & SA_SIGINFO)
1076 err = setup_rt_frame(ksig, set: oldset, regs);
1077 else
1078 err = setup_frame(ksig, set: oldset, regs);
1079
1080 signal_setup_done(failed: err, ksig, stepping: 0);
1081
1082 if (test_thread_flag(TIF_DELAYED_TRACE)) {
1083 regs->sr &= ~0x8000;
1084 send_sig(SIGTRAP, current, 1);
1085 }
1086}
1087
1088/*
1089 * Note that 'init' is a special process: it doesn't get signals it doesn't
1090 * want to handle. Thus you cannot kill init even with a SIGKILL even by
1091 * mistake.
1092 */
1093static void do_signal(struct pt_regs *regs)
1094{
1095 struct ksignal ksig;
1096
1097 current->thread.esp0 = (unsigned long) regs;
1098
1099 if (get_signal(ksig: &ksig)) {
1100 /* Whee! Actually deliver the signal. */
1101 handle_signal(ksig: &ksig, regs);
1102 return;
1103 }
1104
1105 /* Did we come from a system call? */
1106 if (regs->orig_d0 >= 0)
1107 /* Restart the system call - no handlers present */
1108 handle_restart(regs, NULL, has_handler: 0);
1109
1110 /* If there's no signal to deliver, we just restore the saved mask. */
1111 restore_saved_sigmask();
1112}
1113
1114asmlinkage void do_notify_resume(struct pt_regs *regs)
1115{
1116 if (test_thread_flag(TIF_NOTIFY_SIGNAL) ||
1117 test_thread_flag(TIF_SIGPENDING))
1118 do_signal(regs);
1119
1120 if (test_thread_flag(TIF_NOTIFY_RESUME))
1121 resume_user_mode_work(regs);
1122}
1123

source code of linux/arch/m68k/kernel/signal.c