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initial commit with v2.6.9
[linux-2.6.9-moxart.git] / arch / sh / kernel / signal.c
blobfc5ef9960275920e84d68b941a560475a8735202
1 /* $Id: signal.c,v 1.20 2004/01/13 05:52:11 kkojima Exp $
2 *
3 * linux/arch/sh/kernel/signal.c
4 *
5 * Copyright (C) 1991, 1992 Linus Torvalds
6 *
7 * 1997-11-28 Modified for POSIX.1b signals by Richard Henderson
8 *
9 * SuperH version: Copyright (C) 1999, 2000 Niibe Yutaka & Kaz Kojima
10 *
11 */
12
13 #include <linux/sched.h>
14 #include <linux/mm.h>
15 #include <linux/smp.h>
16 #include <linux/smp_lock.h>
17 #include <linux/kernel.h>
18 #include <linux/signal.h>
19 #include <linux/errno.h>
20 #include <linux/wait.h>
21 #include <linux/ptrace.h>
22 #include <linux/unistd.h>
23 #include <linux/stddef.h>
24 #include <linux/tty.h>
25 #include <linux/personality.h>
26 #include <linux/binfmts.h>
27 #include <linux/suspend.h>
28
29 #include <asm/ucontext.h>
30 #include <asm/uaccess.h>
31 #include <asm/pgtable.h>
32 #include <asm/cacheflush.h>
33
34 #define DEBUG_SIG 0
35
36 #define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP)))
37
38 asmlinkage int do_signal(struct pt_regs *regs, sigset_t *oldset);
39
40 /*
41 * Atomically swap in the new signal mask, and wait for a signal.
42 */
43 asmlinkage int
44 sys_sigsuspend(old_sigset_t mask,
45 unsigned long r5, unsigned long r6, unsigned long r7,
46 struct pt_regs regs)
47 {
48 sigset_t saveset;
49
50 mask &= _BLOCKABLE;
51 spin_lock_irq(&current->sighand->siglock);
52 saveset = current->blocked;
53 siginitset(&current->blocked, mask);
54 recalc_sigpending();
55 spin_unlock_irq(&current->sighand->siglock);
56
57 regs.regs[0] = -EINTR;
58 while (1) {
59 current->state = TASK_INTERRUPTIBLE;
60 schedule();
61 if (do_signal(&regs, &saveset))
62 return -EINTR;
63 }
64 }
65
66 asmlinkage int
67 sys_rt_sigsuspend(sigset_t *unewset, size_t sigsetsize,
68 unsigned long r6, unsigned long r7,
69 struct pt_regs regs)
70 {
71 sigset_t saveset, newset;
72
73 /* XXX: Don't preclude handling different sized sigset_t's. */
74 if (sigsetsize != sizeof(sigset_t))
75 return -EINVAL;
76
77 if (copy_from_user(&newset, unewset, sizeof(newset)))
78 return -EFAULT;
79 sigdelsetmask(&newset, ~_BLOCKABLE);
80 spin_lock_irq(&current->sighand->siglock);
81 saveset = current->blocked;
82 current->blocked = newset;
83 recalc_sigpending();
84 spin_unlock_irq(&current->sighand->siglock);
85
86 regs.regs[0] = -EINTR;
87 while (1) {
88 current->state = TASK_INTERRUPTIBLE;
89 schedule();
90 if (do_signal(&regs, &saveset))
91 return -EINTR;
92 }
93 }
94
95 asmlinkage int
96 sys_sigaction(int sig, const struct old_sigaction __user *act,
97 struct old_sigaction __user *oact)
98 {
99 struct k_sigaction new_ka, old_ka;
100 int ret;
101
102 if (act) {
103 old_sigset_t mask;
104 if (verify_area(VERIFY_READ, act, sizeof(*act)) ||
105 __get_user(new_ka.sa.sa_handler, &act->sa_handler) ||
106 __get_user(new_ka.sa.sa_restorer, &act->sa_restorer))
107 return -EFAULT;
108 __get_user(new_ka.sa.sa_flags, &act->sa_flags);
109 __get_user(mask, &act->sa_mask);
110 siginitset(&new_ka.sa.sa_mask, mask);
111 }
112
113 ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL);
114
115 if (!ret && oact) {
116 if (verify_area(VERIFY_WRITE, oact, sizeof(*oact)) ||
117 __put_user(old_ka.sa.sa_handler, &oact->sa_handler) ||
118 __put_user(old_ka.sa.sa_restorer, &oact->sa_restorer))
119 return -EFAULT;
120 __put_user(old_ka.sa.sa_flags, &oact->sa_flags);
121 __put_user(old_ka.sa.sa_mask.sig[0], &oact->sa_mask);
122 }
123
124 return ret;
125 }
126
127 asmlinkage int
128 sys_sigaltstack(const stack_t __user *uss, stack_t __user *uoss,
129 unsigned long r6, unsigned long r7,
130 struct pt_regs regs)
131 {
132 return do_sigaltstack(uss, uoss, regs.regs[15]);
133 }
134
135
136 /*
137 * Do a signal return; undo the signal stack.
138 */
139
140 #define MOVW(n) (0x9300|((n)-2)) /* Move mem word at PC+n to R3 */
141 #define TRAP16 0xc310 /* Syscall w/no args (NR in R3) */
142 #define OR_R0_R0 0x200b /* or r0,r0 (insert to avoid hardware bug) */
143
144 struct sigframe
145 {
146 struct sigcontext sc;
147 unsigned long extramask[_NSIG_WORDS-1];
148 u16 retcode[8];
149 };
150
151 struct rt_sigframe
152 {
153 struct siginfo info;
154 struct ucontext uc;
155 u16 retcode[8];
156 };
157
158 #ifdef CONFIG_CPU_SH4
159 static inline int restore_sigcontext_fpu(struct sigcontext __user *sc)
160 {
161 struct task_struct *tsk = current;
162
163 if (!(cpu_data->flags & CPU_HAS_FPU))
164 return 0;
165
166 tsk->used_math = 1;
167 return __copy_from_user(&tsk->thread.fpu.hard, &sc->sc_fpregs[0],
168 sizeof(long)*(16*2+2));
169 }
170
171 static inline int save_sigcontext_fpu(struct sigcontext __user *sc,
172 struct pt_regs *regs)
173 {
174 struct task_struct *tsk = current;
175
176 if (!(cpu_data->flags & CPU_HAS_FPU))
177 return 0;
178
179 if (!tsk->used_math) {
180 __put_user(0, &sc->sc_ownedfp);
181 return 0;
182 }
183
184 __put_user(1, &sc->sc_ownedfp);
185
186 /* This will cause a "finit" to be triggered by the next
187 attempted FPU operation by the 'current' process.
188 */
189 tsk->used_math = 0;
190
191 unlazy_fpu(tsk, regs);
192 return __copy_to_user(&sc->sc_fpregs[0], &tsk->thread.fpu.hard,
193 sizeof(long)*(16*2+2));
194 }
195 #endif /* CONFIG_CPU_SH4 */
196
197 static int
198 restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc, int *r0_p)
199 {
200 unsigned int err = 0;
201
202 #define COPY(x) err |= __get_user(regs->x, &sc->sc_##x)
203 COPY(regs[1]);
204 COPY(regs[2]); COPY(regs[3]);
205 COPY(regs[4]); COPY(regs[5]);
206 COPY(regs[6]); COPY(regs[7]);
207 COPY(regs[8]); COPY(regs[9]);
208 COPY(regs[10]); COPY(regs[11]);
209 COPY(regs[12]); COPY(regs[13]);
210 COPY(regs[14]); COPY(regs[15]);
211 COPY(gbr); COPY(mach);
212 COPY(macl); COPY(pr);
213 COPY(sr); COPY(pc);
214 #undef COPY
215
216 #ifdef CONFIG_CPU_SH4
217 if (cpu_data->flags & CPU_HAS_FPU) {
218 int owned_fp;
219 struct task_struct *tsk = current;
220
221 regs->sr |= SR_FD; /* Release FPU */
222 clear_fpu(tsk, regs);
223 tsk->used_math = 0;
224 __get_user (owned_fp, &sc->sc_ownedfp);
225 if (owned_fp)
226 err |= restore_sigcontext_fpu(sc);
227 }
228 #endif
229
230 regs->tra = -1; /* disable syscall checks */
231 err |= __get_user(*r0_p, &sc->sc_regs[0]);
232 return err;
233 }
234
235 asmlinkage int sys_sigreturn(unsigned long r4, unsigned long r5,
236 unsigned long r6, unsigned long r7,
237 struct pt_regs regs)
238 {
239 struct sigframe __user *frame = (struct sigframe __user *)regs.regs[15];
240 sigset_t set;
241 int r0;
242
243 if (verify_area(VERIFY_READ, frame, sizeof(*frame)))
244 goto badframe;
245
246 if (__get_user(set.sig[0], &frame->sc.oldmask)
247 || (_NSIG_WORDS > 1
248 && __copy_from_user(&set.sig[1], &frame->extramask,
249 sizeof(frame->extramask))))
250 goto badframe;
251
252 sigdelsetmask(&set, ~_BLOCKABLE);
253
254 spin_lock_irq(&current->sighand->siglock);
255 current->blocked = set;
256 recalc_sigpending();
257 spin_unlock_irq(&current->sighand->siglock);
258
259 if (restore_sigcontext(&regs, &frame->sc, &r0))
260 goto badframe;
261 return r0;
262
263 badframe:
264 force_sig(SIGSEGV, current);
265 return 0;
266 }
267
268 asmlinkage int sys_rt_sigreturn(unsigned long r4, unsigned long r5,
269 unsigned long r6, unsigned long r7,
270 struct pt_regs regs)
271 {
272 struct rt_sigframe __user *frame = (struct rt_sigframe __user *)regs.regs[15];
273 sigset_t set;
274 stack_t st;
275 int r0;
276
277 if (verify_area(VERIFY_READ, frame, sizeof(*frame)))
278 goto badframe;
279
280 if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set)))
281 goto badframe;
282
283 sigdelsetmask(&set, ~_BLOCKABLE);
284 spin_lock_irq(&current->sighand->siglock);
285 current->blocked = set;
286 recalc_sigpending();
287 spin_unlock_irq(&current->sighand->siglock);
288
289 if (restore_sigcontext(&regs, &frame->uc.uc_mcontext, &r0))
290 goto badframe;
291
292 if (__copy_from_user(&st, &frame->uc.uc_stack, sizeof(st)))
293 goto badframe;
294 /* It is more difficult to avoid calling this function than to
295 call it and ignore errors. */
296 do_sigaltstack(&st, NULL, regs.regs[15]);
297
298 return r0;
299
300 badframe:
301 force_sig(SIGSEGV, current);
302 return 0;
303 }
304
305 /*
306 * Set up a signal frame.
307 */
308
309 static int
310 setup_sigcontext(struct sigcontext __user *sc, struct pt_regs *regs,
311 unsigned long mask)
312 {
313 int err = 0;
314
315 #define COPY(x) err |= __put_user(regs->x, &sc->sc_##x)
316 COPY(regs[0]); COPY(regs[1]);
317 COPY(regs[2]); COPY(regs[3]);
318 COPY(regs[4]); COPY(regs[5]);
319 COPY(regs[6]); COPY(regs[7]);
320 COPY(regs[8]); COPY(regs[9]);
321 COPY(regs[10]); COPY(regs[11]);
322 COPY(regs[12]); COPY(regs[13]);
323 COPY(regs[14]); COPY(regs[15]);
324 COPY(gbr); COPY(mach);
325 COPY(macl); COPY(pr);
326 COPY(sr); COPY(pc);
327 #undef COPY
328
329 #ifdef CONFIG_CPU_SH4
330 err |= save_sigcontext_fpu(sc, regs);
331 #endif
332
333 /* non-iBCS2 extensions.. */
334 err |= __put_user(mask, &sc->oldmask);
335
336 return err;
337 }
338
339 /*
340 * Determine which stack to use..
341 */
342 static inline void __user *
343 get_sigframe(struct k_sigaction *ka, unsigned long sp, size_t frame_size)
344 {
345 if ((ka->sa.sa_flags & SA_ONSTACK) != 0 && ! on_sig_stack(sp))
346 sp = current->sas_ss_sp + current->sas_ss_size;
347
348 return (void __user *)((sp - frame_size) & -8ul);
349 }
350
351 static void setup_frame(int sig, struct k_sigaction *ka,
352 sigset_t *set, struct pt_regs *regs)
353 {
354 struct sigframe __user *frame;
355 int err = 0;
356 int signal;
357
358 frame = get_sigframe(ka, regs->regs[15], sizeof(*frame));
359
360 if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
361 goto give_sigsegv;
362
363 signal = current_thread_info()->exec_domain
364 && current_thread_info()->exec_domain->signal_invmap
365 && sig < 32
366 ? current_thread_info()->exec_domain->signal_invmap[sig]
367 : sig;
368
369 err |= setup_sigcontext(&frame->sc, regs, set->sig[0]);
370
371 if (_NSIG_WORDS > 1) {
372 err |= __copy_to_user(frame->extramask, &set->sig[1],
373 sizeof(frame->extramask));
374 }
375
376 /* Set up to return from userspace. If provided, use a stub
377 already in userspace. */
378 if (ka->sa.sa_flags & SA_RESTORER) {
379 regs->pr = (unsigned long) ka->sa.sa_restorer;
380 } else {
381 /* Generate return code (system call to sigreturn) */
382 err |= __put_user(MOVW(7), &frame->retcode[0]);
383 err |= __put_user(TRAP16, &frame->retcode[1]);
384 err |= __put_user(OR_R0_R0, &frame->retcode[2]);
385 err |= __put_user(OR_R0_R0, &frame->retcode[3]);
386 err |= __put_user(OR_R0_R0, &frame->retcode[4]);
387 err |= __put_user(OR_R0_R0, &frame->retcode[5]);
388 err |= __put_user(OR_R0_R0, &frame->retcode[6]);
389 err |= __put_user((__NR_sigreturn), &frame->retcode[7]);
390 regs->pr = (unsigned long) frame->retcode;
391 }
392
393 if (err)
394 goto give_sigsegv;
395
396 /* Set up registers for signal handler */
397 regs->regs[15] = (unsigned long) frame;
398 regs->regs[4] = signal; /* Arg for signal handler */
399 regs->regs[5] = 0;
400 regs->regs[6] = (unsigned long) &frame->sc;
401 regs->pc = (unsigned long) ka->sa.sa_handler;
402
403 set_fs(USER_DS);
404
405 #if DEBUG_SIG
406 printk("SIG deliver (%s:%d): sp=%p pc=%08lx pr=%08lx\n",
407 current->comm, current->pid, frame, regs->pc, regs->pr);
408 #endif
409
410 flush_cache_sigtramp(regs->pr);
411 if ((-regs->pr & (L1_CACHE_BYTES-1)) < sizeof(frame->retcode))
412 flush_cache_sigtramp(regs->pr + L1_CACHE_BYTES);
413 return;
414
415 give_sigsegv:
416 force_sigsegv(sig, current);
417 }
418
419 static void setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
420 sigset_t *set, struct pt_regs *regs)
421 {
422 struct rt_sigframe __user *frame;
423 int err = 0;
424 int signal;
425
426 frame = get_sigframe(ka, regs->regs[15], sizeof(*frame));
427
428 if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
429 goto give_sigsegv;
430
431 signal = current_thread_info()->exec_domain
432 && current_thread_info()->exec_domain->signal_invmap
433 && sig < 32
434 ? current_thread_info()->exec_domain->signal_invmap[sig]
435 : sig;
436
437 err |= copy_siginfo_to_user(&frame->info, info);
438
439 /* Create the ucontext. */
440 err |= __put_user(0, &frame->uc.uc_flags);
441 err |= __put_user(0, &frame->uc.uc_link);
442 err |= __put_user((void *)current->sas_ss_sp,
443 &frame->uc.uc_stack.ss_sp);
444 err |= __put_user(sas_ss_flags(regs->regs[15]),
445 &frame->uc.uc_stack.ss_flags);
446 err |= __put_user(current->sas_ss_size, &frame->uc.uc_stack.ss_size);
447 err |= setup_sigcontext(&frame->uc.uc_mcontext,
448 regs, set->sig[0]);
449 err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
450
451 /* Set up to return from userspace. If provided, use a stub
452 already in userspace. */
453 if (ka->sa.sa_flags & SA_RESTORER) {
454 regs->pr = (unsigned long) ka->sa.sa_restorer;
455 } else {
456 /* Generate return code (system call to rt_sigreturn) */
457 err |= __put_user(MOVW(7), &frame->retcode[0]);
458 err |= __put_user(TRAP16, &frame->retcode[1]);
459 err |= __put_user(OR_R0_R0, &frame->retcode[2]);
460 err |= __put_user(OR_R0_R0, &frame->retcode[3]);
461 err |= __put_user(OR_R0_R0, &frame->retcode[4]);
462 err |= __put_user(OR_R0_R0, &frame->retcode[5]);
463 err |= __put_user(OR_R0_R0, &frame->retcode[6]);
464 err |= __put_user((__NR_rt_sigreturn), &frame->retcode[7]);
465 regs->pr = (unsigned long) frame->retcode;
466 }
467
468 if (err)
469 goto give_sigsegv;
470
471 /* Set up registers for signal handler */
472 regs->regs[15] = (unsigned long) frame;
473 regs->regs[4] = signal; /* Arg for signal handler */
474 regs->regs[5] = (unsigned long) &frame->info;
475 regs->regs[6] = (unsigned long) &frame->uc;
476 regs->pc = (unsigned long) ka->sa.sa_handler;
477
478 set_fs(USER_DS);
479
480 #if DEBUG_SIG
481 printk("SIG deliver (%s:%d): sp=%p pc=%08lx pr=%08lx\n",
482 current->comm, current->pid, frame, regs->pc, regs->pr);
483 #endif
484
485 flush_cache_sigtramp(regs->pr);
486 if ((-regs->pr & (L1_CACHE_BYTES-1)) < sizeof(frame->retcode))
487 flush_cache_sigtramp(regs->pr + L1_CACHE_BYTES);
488 return;
489
490 give_sigsegv:
491 force_sigsegv(sig, current);
492 }
493
494 /*
495 * OK, we're invoking a handler
496 */
497
498 static void
499 handle_signal(unsigned long sig, siginfo_t *info, sigset_t *oldset,
500 struct pt_regs * regs)
501 {
502 struct k_sigaction *ka = &current->sighand->action[sig-1];
503
504 /* Are we from a system call? */
505 if (regs->tra >= 0) {
506 /* If so, check system call restarting.. */
507 switch (regs->regs[0]) {
508 case -ERESTARTNOHAND:
509 regs->regs[0] = -EINTR;
510 break;
511
512 case -ERESTARTSYS:
513 if (!(ka->sa.sa_flags & SA_RESTART)) {
514 regs->regs[0] = -EINTR;
515 break;
516 }
517 /* fallthrough */
518 case -ERESTARTNOINTR:
519 regs->pc -= 2;
520 }
521 } else {
522 /* gUSA handling */
523 #ifdef CONFIG_PREEMPT
524 unsigned long flags;
525
526 local_irq_save(flags);
527 #endif
528 if (regs->regs[15] >= 0xc0000000) {
529 int offset = (int)regs->regs[15];
530
531 /* Reset stack pointer: clear critical region mark */
532 regs->regs[15] = regs->regs[1];
533 if (regs->pc < regs->regs[0])
534 /* Go to rewind point #1 */
535 regs->pc = regs->regs[0] + offset - 2;
536 }
537 #ifdef CONFIG_PREEMPT
538 local_irq_restore(flags);
539 #endif
540 }
541
542 /* Set up the stack frame */
543 if (ka->sa.sa_flags & SA_SIGINFO)
544 setup_rt_frame(sig, ka, info, oldset, regs);
545 else
546 setup_frame(sig, ka, oldset, regs);
547
548 if (ka->sa.sa_flags & SA_ONESHOT)
549 ka->sa.sa_handler = SIG_DFL;
550
551 if (!(ka->sa.sa_flags & SA_NODEFER)) {
552 spin_lock_irq(&current->sighand->siglock);
553 sigorsets(&current->blocked,&current->blocked,&ka->sa.sa_mask);
554 sigaddset(&current->blocked,sig);
555 recalc_sigpending();
556 spin_unlock_irq(&current->sighand->siglock);
557 }
558 }
559
560 /*
561 * Note that 'init' is a special process: it doesn't get signals it doesn't
562 * want to handle. Thus you cannot kill init even with a SIGKILL even by
563 * mistake.
564 *
565 * Note that we go through the signals twice: once to check the signals that
566 * the kernel can handle, and then we build all the user-level signal handling
567 * stack-frames in one go after that.
568 */
569 int do_signal(struct pt_regs *regs, sigset_t *oldset)
570 {
571 siginfo_t info;
572 int signr;
573
574 /*
575 * We want the common case to go fast, which
576 * is why we may in certain cases get here from
577 * kernel mode. Just return without doing anything
578 * if so.
579 */
580 if (!user_mode(regs))
581 return 1;
582
583 if (current->flags & PF_FREEZE) {
584 refrigerator(0);
585 goto no_signal;
586 }
587
588 if (!oldset)
589 oldset = &current->blocked;
590
591 signr = get_signal_to_deliver(&info, regs, NULL);
592 if (signr > 0) {
593 /* Whee! Actually deliver the signal. */
594 handle_signal(signr, &info, oldset, regs);
595 return 1;
596 }
597
598 no_signal:
599 /* Did we come from a system call? */
600 if (regs->tra >= 0) {
601 /* Restart the system call - no handlers present */
602 if (regs->regs[0] == -ERESTARTNOHAND ||
603 regs->regs[0] == -ERESTARTSYS ||
604 regs->regs[0] == -ERESTARTNOINTR ||
605 regs->regs[0] == -ERESTART_RESTARTBLOCK) {
606 regs->pc -= 2;
607 }
608 }
609 return 0;
610 }
MOXA 2.6.9 from sdlinux-moxaart.tgz