1 /*
2 * linux/arch/h8300/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 * uClinux H8/300 support by Yoshinori Sato <ysato@users.sourceforge.jp>
13 * and David McCullough <davidm@snapgear.com>
14 *
15 * Based on
16 * Linux/m68k by Hamish Macdonald
17 */
18
19 /*
20 * ++roman (07/09/96): implemented signal stacks (specially for tosemu on
21 * Atari :-) Current limitation: Only one sigstack can be active at one time.
22 * If a second signal with SA_ONSTACK set arrives while working on a sigstack,
23 * SA_ONSTACK is ignored. This behaviour avoids lots of trouble with nested
24 * signal handlers!
25 */
26
27 #include <linux/sched.h>
28 #include <linux/mm.h>
29 #include <linux/kernel.h>
30 #include <linux/signal.h>
31 #include <linux/syscalls.h>
32 #include <linux/errno.h>
33 #include <linux/wait.h>
34 #include <linux/ptrace.h>
35 #include <linux/unistd.h>
36 #include <linux/stddef.h>
37 #include <linux/highuid.h>
38 #include <linux/personality.h>
39 #include <linux/tty.h>
40 #include <linux/binfmts.h>
41 #include <linux/freezer.h>
42
43 #include <asm/setup.h>
44 #include <asm/uaccess.h>
45 #include <asm/pgtable.h>
46 #include <asm/traps.h>
47 #include <asm/ucontext.h>
48
49 #define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP)))
50
51 asmlinkage int do_signal(struct pt_regs *regs, sigset_t *oldset);
52
53 /*
54 * Atomically swap in the new signal mask, and wait for a signal.
55 */
do_sigsuspend(struct pt_regs * regs)56 asmlinkage int do_sigsuspend(struct pt_regs *regs)
57 {
58 old_sigset_t mask = regs->er3;
59 sigset_t saveset;
60
61 mask &= _BLOCKABLE;
62 spin_lock_irq(¤t->sighand->siglock);
63 saveset = current->blocked;
64 siginitset(¤t->blocked, mask);
65 recalc_sigpending();
66 spin_unlock_irq(¤t->sighand->siglock);
67
68 regs->er0 = -EINTR;
69 while (1) {
70 current->state = TASK_INTERRUPTIBLE;
71 schedule();
72 if (do_signal(regs, &saveset))
73 return -EINTR;
74 }
75 }
76
77 asmlinkage int
do_rt_sigsuspend(struct pt_regs * regs)78 do_rt_sigsuspend(struct pt_regs *regs)
79 {
80 sigset_t *unewset = (sigset_t *)regs->er1;
81 size_t sigsetsize = (size_t)regs->er2;
82 sigset_t saveset, newset;
83
84 /* XXX: Don't preclude handling different sized sigset_t's. */
85 if (sigsetsize != sizeof(sigset_t))
86 return -EINVAL;
87
88 if (copy_from_user(&newset, unewset, sizeof(newset)))
89 return -EFAULT;
90 sigdelsetmask(&newset, ~_BLOCKABLE);
91
92 spin_lock_irq(¤t->sighand->siglock);
93 saveset = current->blocked;
94 current->blocked = newset;
95 recalc_sigpending();
96 spin_unlock_irq(¤t->sighand->siglock);
97
98 regs->er0 = -EINTR;
99 while (1) {
100 current->state = TASK_INTERRUPTIBLE;
101 schedule();
102 if (do_signal(regs, &saveset))
103 return -EINTR;
104 }
105 }
106
107 asmlinkage int
sys_sigaction(int sig,const struct old_sigaction * act,struct old_sigaction * oact)108 sys_sigaction(int sig, const struct old_sigaction *act,
109 struct old_sigaction *oact)
110 {
111 struct k_sigaction new_ka, old_ka;
112 int ret;
113
114 if (act) {
115 old_sigset_t mask;
116 if (!access_ok(VERIFY_READ, act, sizeof(*act)) ||
117 __get_user(new_ka.sa.sa_handler, &act->sa_handler) ||
118 __get_user(new_ka.sa.sa_restorer, &act->sa_restorer))
119 return -EFAULT;
120 __get_user(new_ka.sa.sa_flags, &act->sa_flags);
121 __get_user(mask, &act->sa_mask);
122 siginitset(&new_ka.sa.sa_mask, mask);
123 }
124
125 ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL);
126
127 if (!ret && oact) {
128 if (!access_ok(VERIFY_WRITE, oact, sizeof(*oact)) ||
129 __put_user(old_ka.sa.sa_handler, &oact->sa_handler) ||
130 __put_user(old_ka.sa.sa_restorer, &oact->sa_restorer))
131 return -EFAULT;
132 __put_user(old_ka.sa.sa_flags, &oact->sa_flags);
133 __put_user(old_ka.sa.sa_mask.sig[0], &oact->sa_mask);
134 }
135
136 return ret;
137 }
138
139 asmlinkage int
sys_sigaltstack(const stack_t * uss,stack_t * uoss)140 sys_sigaltstack(const stack_t *uss, stack_t *uoss)
141 {
142 return do_sigaltstack(uss, uoss, rdusp());
143 }
144
145
146 /*
147 * Do a signal return; undo the signal stack.
148 *
149 * Keep the return code on the stack quadword aligned!
150 * That makes the cache flush below easier.
151 */
152
153 struct sigframe
154 {
155 long dummy_er0;
156 long dummy_vector;
157 #if defined(CONFIG_CPU_H8S)
158 short dummy_exr;
159 #endif
160 long dummy_pc;
161 char *pretcode;
162 unsigned char retcode[8];
163 unsigned long extramask[_NSIG_WORDS-1];
164 struct sigcontext sc;
165 int sig;
166 } __attribute__((aligned(2),packed));
167
168 struct rt_sigframe
169 {
170 long dummy_er0;
171 long dummy_vector;
172 #if defined(CONFIG_CPU_H8S)
173 short dummy_exr;
174 #endif
175 long dummy_pc;
176 char *pretcode;
177 struct siginfo *pinfo;
178 void *puc;
179 unsigned char retcode[8];
180 struct siginfo info;
181 struct ucontext uc;
182 int sig;
183 } __attribute__((aligned(2),packed));
184
185 static inline int
restore_sigcontext(struct pt_regs * regs,struct sigcontext * usc,int * pd0)186 restore_sigcontext(struct pt_regs *regs, struct sigcontext *usc,
187 int *pd0)
188 {
189 int err = 0;
190 unsigned int ccr;
191 unsigned int usp;
192 unsigned int er0;
193
194 /* Always make any pending restarted system calls return -EINTR */
195 current_thread_info()->restart_block.fn = do_no_restart_syscall;
196
197 #define COPY(r) err |= __get_user(regs->r, &usc->sc_##r) /* restore passed registers */
198 COPY(er1);
199 COPY(er2);
200 COPY(er3);
201 COPY(er5);
202 COPY(pc);
203 ccr = regs->ccr & 0x10;
204 COPY(ccr);
205 #undef COPY
206 regs->ccr &= 0xef;
207 regs->ccr |= ccr;
208 regs->orig_er0 = -1; /* disable syscall checks */
209 err |= __get_user(usp, &usc->sc_usp);
210 wrusp(usp);
211
212 err |= __get_user(er0, &usc->sc_er0);
213 *pd0 = er0;
214 return err;
215 }
216
do_sigreturn(unsigned long __unused,...)217 asmlinkage int do_sigreturn(unsigned long __unused,...)
218 {
219 struct pt_regs *regs = (struct pt_regs *) (&__unused - 1);
220 unsigned long usp = rdusp();
221 struct sigframe *frame = (struct sigframe *)(usp - 4);
222 sigset_t set;
223 int er0;
224
225 if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
226 goto badframe;
227 if (__get_user(set.sig[0], &frame->sc.sc_mask) ||
228 (_NSIG_WORDS > 1 &&
229 __copy_from_user(&set.sig[1], &frame->extramask,
230 sizeof(frame->extramask))))
231 goto badframe;
232
233 sigdelsetmask(&set, ~_BLOCKABLE);
234 spin_lock_irq(¤t->sighand->siglock);
235 current->blocked = set;
236 recalc_sigpending();
237 spin_unlock_irq(¤t->sighand->siglock);
238
239 if (restore_sigcontext(regs, &frame->sc, &er0))
240 goto badframe;
241 return er0;
242
243 badframe:
244 force_sig(SIGSEGV, current);
245 return 0;
246 }
247
do_rt_sigreturn(unsigned long __unused,...)248 asmlinkage int do_rt_sigreturn(unsigned long __unused,...)
249 {
250 struct pt_regs *regs = (struct pt_regs *) &__unused;
251 unsigned long usp = rdusp();
252 struct rt_sigframe *frame = (struct rt_sigframe *)(usp - 4);
253 sigset_t set;
254 int er0;
255
256 if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
257 goto badframe;
258 if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set)))
259 goto badframe;
260
261 sigdelsetmask(&set, ~_BLOCKABLE);
262 spin_unlock_irq(¤t->sighand->siglock);
263 current->blocked = set;
264 recalc_sigpending();
265 spin_lock_irq(¤t->sighand->siglock);
266
267 if (restore_sigcontext(regs, &frame->uc.uc_mcontext, &er0))
268 goto badframe;
269
270 if (do_sigaltstack(&frame->uc.uc_stack, NULL, usp) == -EFAULT)
271 goto badframe;
272
273 return er0;
274
275 badframe:
276 force_sig(SIGSEGV, current);
277 return 0;
278 }
279
setup_sigcontext(struct sigcontext __user * sc,struct pt_regs * regs,unsigned long mask)280 static int setup_sigcontext(struct sigcontext __user *sc, struct pt_regs *regs,
281 unsigned long mask)
282 {
283 int err = 0;
284
285 err |= __put_user(regs->er0, &sc->sc_er0);
286 err |= __put_user(regs->er1, &sc->sc_er1);
287 err |= __put_user(regs->er2, &sc->sc_er2);
288 err |= __put_user(regs->er3, &sc->sc_er3);
289 err |= __put_user(regs->er4, &sc->sc_er4);
290 err |= __put_user(regs->er5, &sc->sc_er5);
291 err |= __put_user(regs->er6, &sc->sc_er6);
292 err |= __put_user(rdusp(), &sc->sc_usp);
293 err |= __put_user(regs->pc, &sc->sc_pc);
294 err |= __put_user(regs->ccr, &sc->sc_ccr);
295 err |= __put_user(mask, &sc->sc_mask);
296
297 return err;
298 }
299
300 static inline void *
get_sigframe(struct k_sigaction * ka,struct pt_regs * regs,size_t frame_size)301 get_sigframe(struct k_sigaction *ka, struct pt_regs *regs, size_t frame_size)
302 {
303 unsigned long usp;
304
305 /* Default to using normal stack. */
306 usp = rdusp();
307
308 /* This is the X/Open sanctioned signal stack switching. */
309 if (ka->sa.sa_flags & SA_ONSTACK) {
310 if (!sas_ss_flags(usp))
311 usp = current->sas_ss_sp + current->sas_ss_size;
312 }
313 return (void *)((usp - frame_size) & -8UL);
314 }
315
setup_frame(int sig,struct k_sigaction * ka,sigset_t * set,struct pt_regs * regs)316 static void setup_frame (int sig, struct k_sigaction *ka,
317 sigset_t *set, struct pt_regs *regs)
318 {
319 struct sigframe *frame;
320 int err = 0;
321 int usig;
322 unsigned char *ret;
323
324 frame = get_sigframe(ka, regs, sizeof(*frame));
325
326 if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
327 goto give_sigsegv;
328
329 usig = current_thread_info()->exec_domain
330 && current_thread_info()->exec_domain->signal_invmap
331 && sig < 32
332 ? current_thread_info()->exec_domain->signal_invmap[sig]
333 : sig;
334
335 err |= __put_user(usig, &frame->sig);
336 if (err)
337 goto give_sigsegv;
338
339 err |= setup_sigcontext(&frame->sc, regs, set->sig[0]);
340 if (err)
341 goto give_sigsegv;
342
343 if (_NSIG_WORDS > 1) {
344 err |= copy_to_user(frame->extramask, &set->sig[1],
345 sizeof(frame->extramask));
346 if (err)
347 goto give_sigsegv;
348 }
349
350 ret = frame->retcode;
351 if (ka->sa.sa_flags & SA_RESTORER)
352 ret = (unsigned char *)(ka->sa.sa_restorer);
353 else {
354 /* sub.l er0,er0; mov.b #__NR_sigreturn,r0l; trapa #0 */
355 err |= __put_user(0x1a80f800 + (__NR_sigreturn & 0xff),
356 (unsigned long *)(frame->retcode + 0));
357 err |= __put_user(0x5700, (unsigned short *)(frame->retcode + 4));
358 }
359
360 /* Set up to return from userspace. */
361 err |= __put_user(ret, &frame->pretcode);
362
363 if (err)
364 goto give_sigsegv;
365
366 /* Set up registers for signal handler */
367 wrusp ((unsigned long) frame);
368 regs->pc = (unsigned long) ka->sa.sa_handler;
369 regs->er0 = (current_thread_info()->exec_domain
370 && current_thread_info()->exec_domain->signal_invmap
371 && sig < 32
372 ? current_thread_info()->exec_domain->signal_invmap[sig]
373 : sig);
374 regs->er1 = (unsigned long)&(frame->sc);
375 regs->er5 = current->mm->start_data; /* GOT base */
376
377 return;
378
379 give_sigsegv:
380 force_sigsegv(sig, current);
381 }
382
setup_rt_frame(int sig,struct k_sigaction * ka,siginfo_t * info,sigset_t * set,struct pt_regs * regs)383 static void setup_rt_frame (int sig, struct k_sigaction *ka, siginfo_t *info,
384 sigset_t *set, struct pt_regs *regs)
385 {
386 struct rt_sigframe *frame;
387 int err = 0;
388 int usig;
389 unsigned char *ret;
390
391 frame = get_sigframe(ka, regs, sizeof(*frame));
392
393 if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
394 goto give_sigsegv;
395
396 usig = current_thread_info()->exec_domain
397 && current_thread_info()->exec_domain->signal_invmap
398 && sig < 32
399 ? current_thread_info()->exec_domain->signal_invmap[sig]
400 : sig;
401
402 err |= __put_user(usig, &frame->sig);
403 if (err)
404 goto give_sigsegv;
405
406 err |= __put_user(&frame->info, &frame->pinfo);
407 err |= __put_user(&frame->uc, &frame->puc);
408 err |= copy_siginfo_to_user(&frame->info, info);
409 if (err)
410 goto give_sigsegv;
411
412 /* Create the ucontext. */
413 err |= __put_user(0, &frame->uc.uc_flags);
414 err |= __put_user(0, &frame->uc.uc_link);
415 err |= __put_user((void *)current->sas_ss_sp,
416 &frame->uc.uc_stack.ss_sp);
417 err |= __put_user(sas_ss_flags(rdusp()),
418 &frame->uc.uc_stack.ss_flags);
419 err |= __put_user(current->sas_ss_size, &frame->uc.uc_stack.ss_size);
420 err |= setup_sigcontext(&frame->uc.uc_mcontext, regs, set->sig[0]);
421 err |= copy_to_user (&frame->uc.uc_sigmask, set, sizeof(*set));
422 if (err)
423 goto give_sigsegv;
424
425 /* Set up to return from userspace. */
426 ret = frame->retcode;
427 if (ka->sa.sa_flags & SA_RESTORER)
428 ret = (unsigned char *)(ka->sa.sa_restorer);
429 else {
430 /* sub.l er0,er0; mov.b #__NR_sigreturn,r0l; trapa #0 */
431 err |= __put_user(0x1a80f800 + (__NR_sigreturn & 0xff),
432 (unsigned long *)(frame->retcode + 0));
433 err |= __put_user(0x5700, (unsigned short *)(frame->retcode + 4));
434 }
435 err |= __put_user(ret, &frame->pretcode);
436
437 if (err)
438 goto give_sigsegv;
439
440 /* Set up registers for signal handler */
441 wrusp ((unsigned long) frame);
442 regs->pc = (unsigned long) ka->sa.sa_handler;
443 regs->er0 = (current_thread_info()->exec_domain
444 && current_thread_info()->exec_domain->signal_invmap
445 && sig < 32
446 ? current_thread_info()->exec_domain->signal_invmap[sig]
447 : sig);
448 regs->er1 = (unsigned long)&(frame->info);
449 regs->er2 = (unsigned long)&frame->uc;
450 regs->er5 = current->mm->start_data; /* GOT base */
451
452 return;
453
454 give_sigsegv:
455 force_sigsegv(sig, current);
456 }
457
458 /*
459 * OK, we're invoking a handler
460 */
461 static void
handle_signal(unsigned long sig,siginfo_t * info,struct k_sigaction * ka,sigset_t * oldset,struct pt_regs * regs)462 handle_signal(unsigned long sig, siginfo_t *info, struct k_sigaction *ka,
463 sigset_t *oldset, struct pt_regs * regs)
464 {
465 /* are we from a system call? */
466 if (regs->orig_er0 >= 0) {
467 switch (regs->er0) {
468 case -ERESTART_RESTARTBLOCK:
469 case -ERESTARTNOHAND:
470 regs->er0 = -EINTR;
471 break;
472
473 case -ERESTARTSYS:
474 if (!(ka->sa.sa_flags & SA_RESTART)) {
475 regs->er0 = -EINTR;
476 break;
477 }
478 /* fallthrough */
479 case -ERESTARTNOINTR:
480 regs->er0 = regs->orig_er0;
481 regs->pc -= 2;
482 }
483 }
484
485 /* set up the stack frame */
486 if (ka->sa.sa_flags & SA_SIGINFO)
487 setup_rt_frame(sig, ka, info, oldset, regs);
488 else
489 setup_frame(sig, ka, oldset, regs);
490
491 spin_lock_irq(¤t->sighand->siglock);
492 sigorsets(¤t->blocked,¤t->blocked,&ka->sa.sa_mask);
493 if (!(ka->sa.sa_flags & SA_NODEFER))
494 sigaddset(¤t->blocked,sig);
495 recalc_sigpending();
496 spin_unlock_irq(¤t->sighand->siglock);
497 }
498
499 /*
500 * Note that 'init' is a special process: it doesn't get signals it doesn't
501 * want to handle. Thus you cannot kill init even with a SIGKILL even by
502 * mistake.
503 */
do_signal(struct pt_regs * regs,sigset_t * oldset)504 asmlinkage int do_signal(struct pt_regs *regs, sigset_t *oldset)
505 {
506 siginfo_t info;
507 int signr;
508 struct k_sigaction ka;
509
510 /*
511 * We want the common case to go fast, which
512 * is why we may in certain cases get here from
513 * kernel mode. Just return without doing anything
514 * if so.
515 */
516 if ((regs->ccr & 0x10))
517 return 1;
518
519 if (try_to_freeze())
520 goto no_signal;
521
522 current->thread.esp0 = (unsigned long) regs;
523
524 if (!oldset)
525 oldset = ¤t->blocked;
526
527 signr = get_signal_to_deliver(&info, &ka, regs, NULL);
528 if (signr > 0) {
529 /* Whee! Actually deliver the signal. */
530 handle_signal(signr, &info, &ka, oldset, regs);
531 return 1;
532 }
533 no_signal:
534 /* Did we come from a system call? */
535 if (regs->orig_er0 >= 0) {
536 /* Restart the system call - no handlers present */
537 if (regs->er0 == -ERESTARTNOHAND ||
538 regs->er0 == -ERESTARTSYS ||
539 regs->er0 == -ERESTARTNOINTR) {
540 regs->er0 = regs->orig_er0;
541 regs->pc -= 2;
542 }
543 if (regs->er0 == -ERESTART_RESTARTBLOCK){
544 regs->er0 = __NR_restart_syscall;
545 regs->pc -= 2;
546 }
547 }
548 return 0;
549 }
550
do_notify_resume(struct pt_regs * regs,u32 thread_info_flags)551 asmlinkage void do_notify_resume(struct pt_regs *regs, u32 thread_info_flags)
552 {
553 if (thread_info_flags & (_TIF_SIGPENDING | _TIF_RESTORE_SIGMASK))
554 do_signal(regs, NULL);
555 }
556