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[TG3]: Set minimal hw interrupt mitigation.
[linux-2.6/verdex.git] / arch / sh / kernel / signal.c
blob06f1b47eded96b03ab5a55c58c97cd9c3a4ffe41
1 /*
2 * linux/arch/sh/kernel/signal.c
3 *
4 * Copyright (C) 1991, 1992 Linus Torvalds
5 *
6 * 1997-11-28 Modified for POSIX.1b signals by Richard Henderson
7 *
8 * SuperH version: Copyright (C) 1999, 2000 Niibe Yutaka & Kaz Kojima
9 *
10 */
11
12 #include <linux/sched.h>
13 #include <linux/mm.h>
14 #include <linux/smp.h>
15 #include <linux/smp_lock.h>
16 #include <linux/kernel.h>
17 #include <linux/signal.h>
18 #include <linux/errno.h>
19 #include <linux/wait.h>
20 #include <linux/ptrace.h>
21 #include <linux/unistd.h>
22 #include <linux/stddef.h>
23 #include <linux/tty.h>
24 #include <linux/personality.h>
25 #include <linux/binfmts.h>
26
27 #include <asm/ucontext.h>
28 #include <asm/uaccess.h>
29 #include <asm/pgtable.h>
30 #include <asm/cacheflush.h>
31
32 #define DEBUG_SIG 0
33
34 #define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP)))
35
36 asmlinkage int do_signal(struct pt_regs *regs, sigset_t *oldset);
37
38 /*
39 * Atomically swap in the new signal mask, and wait for a signal.
40 */
41 asmlinkage int
42 sys_sigsuspend(old_sigset_t mask,
43 unsigned long r5, unsigned long r6, unsigned long r7,
44 struct pt_regs regs)
45 {
46 sigset_t saveset;
47
48 mask &= _BLOCKABLE;
49 spin_lock_irq(&current->sighand->siglock);
50 saveset = current->blocked;
51 siginitset(&current->blocked, mask);
52 recalc_sigpending();
53 spin_unlock_irq(&current->sighand->siglock);
54
55 regs.regs[0] = -EINTR;
56 while (1) {
57 current->state = TASK_INTERRUPTIBLE;
58 schedule();
59 if (do_signal(&regs, &saveset))
60 return -EINTR;
61 }
62 }
63
64 asmlinkage int
65 sys_rt_sigsuspend(sigset_t *unewset, size_t sigsetsize,
66 unsigned long r6, unsigned long r7,
67 struct pt_regs regs)
68 {
69 sigset_t saveset, newset;
70
71 /* XXX: Don't preclude handling different sized sigset_t's. */
72 if (sigsetsize != sizeof(sigset_t))
73 return -EINVAL;
74
75 if (copy_from_user(&newset, unewset, sizeof(newset)))
76 return -EFAULT;
77 sigdelsetmask(&newset, ~_BLOCKABLE);
78 spin_lock_irq(&current->sighand->siglock);
79 saveset = current->blocked;
80 current->blocked = newset;
81 recalc_sigpending();
82 spin_unlock_irq(&current->sighand->siglock);
83
84 regs.regs[0] = -EINTR;
85 while (1) {
86 current->state = TASK_INTERRUPTIBLE;
87 schedule();
88 if (do_signal(&regs, &saveset))
89 return -EINTR;
90 }
91 }
92
93 asmlinkage int
94 sys_sigaction(int sig, const struct old_sigaction __user *act,
95 struct old_sigaction __user *oact)
96 {
97 struct k_sigaction new_ka, old_ka;
98 int ret;
99
100 if (act) {
101 old_sigset_t mask;
102 if (!access_ok(VERIFY_READ, act, sizeof(*act)) ||
103 __get_user(new_ka.sa.sa_handler, &act->sa_handler) ||
104 __get_user(new_ka.sa.sa_restorer, &act->sa_restorer))
105 return -EFAULT;
106 __get_user(new_ka.sa.sa_flags, &act->sa_flags);
107 __get_user(mask, &act->sa_mask);
108 siginitset(&new_ka.sa.sa_mask, mask);
109 }
110
111 ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL);
112
113 if (!ret && oact) {
114 if (!access_ok(VERIFY_WRITE, oact, sizeof(*oact)) ||
115 __put_user(old_ka.sa.sa_handler, &oact->sa_handler) ||
116 __put_user(old_ka.sa.sa_restorer, &oact->sa_restorer))
117 return -EFAULT;
118 __put_user(old_ka.sa.sa_flags, &oact->sa_flags);
119 __put_user(old_ka.sa.sa_mask.sig[0], &oact->sa_mask);
120 }
121
122 return ret;
123 }
124
125 asmlinkage int
126 sys_sigaltstack(const stack_t __user *uss, stack_t __user *uoss,
127 unsigned long r6, unsigned long r7,
128 struct pt_regs regs)
129 {
130 return do_sigaltstack(uss, uoss, regs.regs[15]);
131 }
132
133
134 /*
135 * Do a signal return; undo the signal stack.
136 */
137
138 #define MOVW(n) (0x9300|((n)-2)) /* Move mem word at PC+n to R3 */
139 #define TRAP16 0xc310 /* Syscall w/no args (NR in R3) */
140 #define OR_R0_R0 0x200b /* or r0,r0 (insert to avoid hardware bug) */
141
142 struct sigframe
143 {
144 struct sigcontext sc;
145 unsigned long extramask[_NSIG_WORDS-1];
146 u16 retcode[8];
147 };
148
149 struct rt_sigframe
150 {
151 struct siginfo info;
152 struct ucontext uc;
153 u16 retcode[8];
154 };
155
156 #ifdef CONFIG_SH_FPU
157 static inline int restore_sigcontext_fpu(struct sigcontext __user *sc)
158 {
159 struct task_struct *tsk = current;
160
161 if (!(cpu_data->flags & CPU_HAS_FPU))
162 return 0;
163
164 set_used_math();
165 return __copy_from_user(&tsk->thread.fpu.hard, &sc->sc_fpregs[0],
166 sizeof(long)*(16*2+2));
167 }
168
169 static inline int save_sigcontext_fpu(struct sigcontext __user *sc,
170 struct pt_regs *regs)
171 {
172 struct task_struct *tsk = current;
173
174 if (!(cpu_data->flags & CPU_HAS_FPU))
175 return 0;
176
177 if (!used_math()) {
178 __put_user(0, &sc->sc_ownedfp);
179 return 0;
180 }
181
182 __put_user(1, &sc->sc_ownedfp);
183
184 /* This will cause a "finit" to be triggered by the next
185 attempted FPU operation by the 'current' process.
186 */
187 clear_used_math();
188
189 unlazy_fpu(tsk, regs);
190 return __copy_to_user(&sc->sc_fpregs[0], &tsk->thread.fpu.hard,
191 sizeof(long)*(16*2+2));
192 }
193 #endif /* CONFIG_SH_FPU */
194
195 static int
196 restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc, int *r0_p)
197 {
198 unsigned int err = 0;
199
200 #define COPY(x) err |= __get_user(regs->x, &sc->sc_##x)
201 COPY(regs[1]);
202 COPY(regs[2]); COPY(regs[3]);
203 COPY(regs[4]); COPY(regs[5]);
204 COPY(regs[6]); COPY(regs[7]);
205 COPY(regs[8]); COPY(regs[9]);
206 COPY(regs[10]); COPY(regs[11]);
207 COPY(regs[12]); COPY(regs[13]);
208 COPY(regs[14]); COPY(regs[15]);
209 COPY(gbr); COPY(mach);
210 COPY(macl); COPY(pr);
211 COPY(sr); COPY(pc);
212 #undef COPY
213
214 #ifdef CONFIG_SH_FPU
215 if (cpu_data->flags & CPU_HAS_FPU) {
216 int owned_fp;
217 struct task_struct *tsk = current;
218
219 regs->sr |= SR_FD; /* Release FPU */
220 clear_fpu(tsk, regs);
221 clear_used_math();
222 __get_user (owned_fp, &sc->sc_ownedfp);
223 if (owned_fp)
224 err |= restore_sigcontext_fpu(sc);
225 }
226 #endif
227
228 regs->tra = -1; /* disable syscall checks */
229 err |= __get_user(*r0_p, &sc->sc_regs[0]);
230 return err;
231 }
232
233 asmlinkage int sys_sigreturn(unsigned long r4, unsigned long r5,
234 unsigned long r6, unsigned long r7,
235 struct pt_regs regs)
236 {
237 struct sigframe __user *frame = (struct sigframe __user *)regs.regs[15];
238 sigset_t set;
239 int r0;
240
241 if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
242 goto badframe;
243
244 if (__get_user(set.sig[0], &frame->sc.oldmask)
245 || (_NSIG_WORDS > 1
246 && __copy_from_user(&set.sig[1], &frame->extramask,
247 sizeof(frame->extramask))))
248 goto badframe;
249
250 sigdelsetmask(&set, ~_BLOCKABLE);
251
252 spin_lock_irq(&current->sighand->siglock);
253 current->blocked = set;
254 recalc_sigpending();
255 spin_unlock_irq(&current->sighand->siglock);
256
257 if (restore_sigcontext(&regs, &frame->sc, &r0))
258 goto badframe;
259 return r0;
260
261 badframe:
262 force_sig(SIGSEGV, current);
263 return 0;
264 }
265
266 asmlinkage int sys_rt_sigreturn(unsigned long r4, unsigned long r5,
267 unsigned long r6, unsigned long r7,
268 struct pt_regs regs)
269 {
270 struct rt_sigframe __user *frame = (struct rt_sigframe __user *)regs.regs[15];
271 sigset_t set;
272 stack_t st;
273 int r0;
274
275 if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
276 goto badframe;
277
278 if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set)))
279 goto badframe;
280
281 sigdelsetmask(&set, ~_BLOCKABLE);
282 spin_lock_irq(&current->sighand->siglock);
283 current->blocked = set;
284 recalc_sigpending();
285 spin_unlock_irq(&current->sighand->siglock);
286
287 if (restore_sigcontext(&regs, &frame->uc.uc_mcontext, &r0))
288 goto badframe;
289
290 if (__copy_from_user(&st, &frame->uc.uc_stack, sizeof(st)))
291 goto badframe;
292 /* It is more difficult to avoid calling this function than to
293 call it and ignore errors. */
294 do_sigaltstack(&st, NULL, regs.regs[15]);
295
296 return r0;
297
298 badframe:
299 force_sig(SIGSEGV, current);
300 return 0;
301 }
302
303 /*
304 * Set up a signal frame.
305 */
306
307 static int
308 setup_sigcontext(struct sigcontext __user *sc, struct pt_regs *regs,
309 unsigned long mask)
310 {
311 int err = 0;
312
313 #define COPY(x) err |= __put_user(regs->x, &sc->sc_##x)
314 COPY(regs[0]); COPY(regs[1]);
315 COPY(regs[2]); COPY(regs[3]);
316 COPY(regs[4]); COPY(regs[5]);
317 COPY(regs[6]); COPY(regs[7]);
318 COPY(regs[8]); COPY(regs[9]);
319 COPY(regs[10]); COPY(regs[11]);
320 COPY(regs[12]); COPY(regs[13]);
321 COPY(regs[14]); COPY(regs[15]);
322 COPY(gbr); COPY(mach);
323 COPY(macl); COPY(pr);
324 COPY(sr); COPY(pc);
325 #undef COPY
326
327 #ifdef CONFIG_SH_FPU
328 err |= save_sigcontext_fpu(sc, regs);
329 #endif
330
331 /* non-iBCS2 extensions.. */
332 err |= __put_user(mask, &sc->oldmask);
333
334 return err;
335 }
336
337 /*
338 * Determine which stack to use..
339 */
340 static inline void __user *
341 get_sigframe(struct k_sigaction *ka, unsigned long sp, size_t frame_size)
342 {
343 if (ka->sa.sa_flags & SA_ONSTACK) {
344 if (sas_ss_flags(sp) == 0)
345 sp = current->sas_ss_sp + current->sas_ss_size;
346 }
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, struct k_sigaction *ka, siginfo_t *info,
500 sigset_t *oldset, struct pt_regs *regs)
501 {
502 /* Are we from a system call? */
503 if (regs->tra >= 0) {
504 /* If so, check system call restarting.. */
505 switch (regs->regs[0]) {
506 case -ERESTARTNOHAND:
507 regs->regs[0] = -EINTR;
508 break;
509
510 case -ERESTARTSYS:
511 if (!(ka->sa.sa_flags & SA_RESTART)) {
512 regs->regs[0] = -EINTR;
513 break;
514 }
515 /* fallthrough */
516 case -ERESTARTNOINTR:
517 regs->pc -= 2;
518 }
519 } else {
520 /* gUSA handling */
521 #ifdef CONFIG_PREEMPT
522 unsigned long flags;
523
524 local_irq_save(flags);
525 #endif
526 if (regs->regs[15] >= 0xc0000000) {
527 int offset = (int)regs->regs[15];
528
529 /* Reset stack pointer: clear critical region mark */
530 regs->regs[15] = regs->regs[1];
531 if (regs->pc < regs->regs[0])
532 /* Go to rewind point #1 */
533 regs->pc = regs->regs[0] + offset - 2;
534 }
535 #ifdef CONFIG_PREEMPT
536 local_irq_restore(flags);
537 #endif
538 }
539
540 /* Set up the stack frame */
541 if (ka->sa.sa_flags & SA_SIGINFO)
542 setup_rt_frame(sig, ka, info, oldset, regs);
543 else
544 setup_frame(sig, ka, oldset, regs);
545
546 if (ka->sa.sa_flags & SA_ONESHOT)
547 ka->sa.sa_handler = SIG_DFL;
548
549 if (!(ka->sa.sa_flags & SA_NODEFER)) {
550 spin_lock_irq(&current->sighand->siglock);
551 sigorsets(&current->blocked,&current->blocked,&ka->sa.sa_mask);
552 sigaddset(&current->blocked,sig);
553 recalc_sigpending();
554 spin_unlock_irq(&current->sighand->siglock);
555 }
556 }
557
558 /*
559 * Note that 'init' is a special process: it doesn't get signals it doesn't
560 * want to handle. Thus you cannot kill init even with a SIGKILL even by
561 * mistake.
562 *
563 * Note that we go through the signals twice: once to check the signals that
564 * the kernel can handle, and then we build all the user-level signal handling
565 * stack-frames in one go after that.
566 */
567 int do_signal(struct pt_regs *regs, sigset_t *oldset)
568 {
569 siginfo_t info;
570 int signr;
571 struct k_sigaction ka;
572
573 /*
574 * We want the common case to go fast, which
575 * is why we may in certain cases get here from
576 * kernel mode. Just return without doing anything
577 * if so.
578 */
579 if (!user_mode(regs))
580 return 1;
581
582 if (try_to_freeze(0))
583 goto no_signal;
584
585 if (!oldset)
586 oldset = &current->blocked;
587
588 signr = get_signal_to_deliver(&info, &ka, regs, NULL);
589 if (signr > 0) {
590 /* Whee! Actually deliver the signal. */
591 handle_signal(signr, &ka, &info, oldset, regs);
592 return 1;
593 }
594
595 no_signal:
596 /* Did we come from a system call? */
597 if (regs->tra >= 0) {
598 /* Restart the system call - no handlers present */
599 if (regs->regs[0] == -ERESTARTNOHAND ||
600 regs->regs[0] == -ERESTARTSYS ||
601 regs->regs[0] == -ERESTARTNOINTR ||
602 regs->regs[0] == -ERESTART_RESTARTBLOCK) {
603 regs->pc -= 2;
604 }
605 }
606 return 0;
607 }
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