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1da177e4 LT |
1 | /* |
2 | * arch/v850/kernel/signal.c -- Signal handling | |
3 | * | |
4 | * Copyright (C) 2001,02,03 NEC Electronics Corporation | |
5 | * Copyright (C) 2001,02,03 Miles Bader <miles@gnu.org> | |
6 | * Copyright (C) 1999,2000,2002 Niibe Yutaka & Kaz Kojima | |
7 | * Copyright (C) 1991,1992 Linus Torvalds | |
8 | * | |
9 | * This file is subject to the terms and conditions of the GNU General | |
10 | * Public License. See the file COPYING in the main directory of this | |
11 | * archive for more details. | |
12 | * | |
13 | * 1997-11-28 Modified for POSIX.1b signals by Richard Henderson | |
14 | * | |
15 | * This file was derived from the sh version, arch/sh/kernel/signal.c | |
16 | */ | |
17 | ||
18 | #include <linux/mm.h> | |
19 | #include <linux/smp.h> | |
20 | #include <linux/smp_lock.h> | |
21 | #include <linux/kernel.h> | |
22 | #include <linux/signal.h> | |
23 | #include <linux/errno.h> | |
24 | #include <linux/wait.h> | |
25 | #include <linux/ptrace.h> | |
26 | #include <linux/unistd.h> | |
27 | #include <linux/stddef.h> | |
28 | #include <linux/personality.h> | |
29 | #include <linux/tty.h> | |
30 | ||
31 | #include <asm/ucontext.h> | |
32 | #include <asm/uaccess.h> | |
33 | #include <asm/pgtable.h> | |
34 | #include <asm/pgalloc.h> | |
35 | #include <asm/thread_info.h> | |
36 | #include <asm/cacheflush.h> | |
37 | ||
38 | #define DEBUG_SIG 0 | |
39 | ||
40 | #define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP))) | |
41 | ||
42 | asmlinkage int do_signal(struct pt_regs *regs, sigset_t *oldset); | |
43 | ||
44 | /* | |
45 | * Atomically swap in the new signal mask, and wait for a signal. | |
46 | */ | |
47 | asmlinkage int | |
48 | sys_sigsuspend(old_sigset_t mask, struct pt_regs *regs) | |
49 | { | |
50 | sigset_t saveset; | |
51 | ||
52 | mask &= _BLOCKABLE; | |
53 | spin_lock_irq(¤t->sighand->siglock); | |
54 | saveset = current->blocked; | |
55 | siginitset(¤t->blocked, mask); | |
56 | recalc_sigpending(); | |
57 | spin_unlock_irq(¤t->sighand->siglock); | |
58 | ||
59 | regs->gpr[GPR_RVAL] = -EINTR; | |
60 | while (1) { | |
61 | current->state = TASK_INTERRUPTIBLE; | |
62 | schedule(); | |
63 | if (do_signal(regs, &saveset)) | |
64 | return -EINTR; | |
65 | } | |
66 | } | |
67 | ||
68 | asmlinkage int | |
69 | sys_rt_sigsuspend(sigset_t *unewset, size_t sigsetsize, | |
70 | struct pt_regs *regs) | |
71 | { | |
72 | sigset_t saveset, newset; | |
73 | ||
74 | /* XXX: Don't preclude handling different sized sigset_t's. */ | |
75 | if (sigsetsize != sizeof(sigset_t)) | |
76 | return -EINVAL; | |
77 | ||
78 | if (copy_from_user(&newset, unewset, sizeof(newset))) | |
79 | return -EFAULT; | |
80 | sigdelsetmask(&newset, ~_BLOCKABLE); | |
81 | spin_lock_irq(¤t->sighand->siglock); | |
82 | saveset = current->blocked; | |
83 | current->blocked = newset; | |
84 | recalc_sigpending(); | |
85 | spin_unlock_irq(¤t->sighand->siglock); | |
86 | ||
87 | regs->gpr[GPR_RVAL] = -EINTR; | |
88 | while (1) { | |
89 | current->state = TASK_INTERRUPTIBLE; | |
90 | schedule(); | |
91 | if (do_signal(regs, &saveset)) | |
92 | return -EINTR; | |
93 | } | |
94 | } | |
95 | ||
96 | asmlinkage int | |
97 | sys_sigaction(int sig, const struct old_sigaction *act, | |
98 | struct old_sigaction *oact) | |
99 | { | |
100 | struct k_sigaction new_ka, old_ka; | |
101 | int ret; | |
102 | ||
103 | if (act) { | |
104 | old_sigset_t mask; | |
105 | if (!access_ok(VERIFY_READ, act, sizeof(*act)) || | |
106 | __get_user(new_ka.sa.sa_handler, &act->sa_handler) || | |
107 | __get_user(new_ka.sa.sa_restorer, &act->sa_restorer)) | |
108 | return -EFAULT; | |
109 | __get_user(new_ka.sa.sa_flags, &act->sa_flags); | |
110 | __get_user(mask, &act->sa_mask); | |
111 | siginitset(&new_ka.sa.sa_mask, mask); | |
112 | } | |
113 | ||
114 | ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL); | |
115 | ||
116 | if (!ret && oact) { | |
117 | if (!access_ok(VERIFY_WRITE, oact, sizeof(*oact)) || | |
118 | __put_user(old_ka.sa.sa_handler, &oact->sa_handler) || | |
119 | __put_user(old_ka.sa.sa_restorer, &oact->sa_restorer)) | |
120 | return -EFAULT; | |
121 | __put_user(old_ka.sa.sa_flags, &oact->sa_flags); | |
122 | __put_user(old_ka.sa.sa_mask.sig[0], &oact->sa_mask); | |
123 | } | |
124 | ||
125 | return ret; | |
126 | } | |
127 | ||
128 | asmlinkage int | |
129 | sys_sigaltstack(const stack_t *uss, stack_t *uoss, | |
130 | struct pt_regs *regs) | |
131 | { | |
132 | return do_sigaltstack(uss, uoss, regs->gpr[GPR_SP]); | |
133 | } | |
134 | ||
135 | ||
136 | /* | |
137 | * Do a signal return; undo the signal stack. | |
138 | */ | |
139 | ||
140 | struct sigframe | |
141 | { | |
142 | struct sigcontext sc; | |
143 | unsigned long extramask[_NSIG_WORDS-1]; | |
144 | unsigned long tramp[2]; /* signal trampoline */ | |
145 | }; | |
146 | ||
147 | struct rt_sigframe | |
148 | { | |
149 | struct siginfo info; | |
150 | struct ucontext uc; | |
151 | unsigned long tramp[2]; /* signal trampoline */ | |
152 | }; | |
153 | ||
154 | static int | |
155 | restore_sigcontext(struct pt_regs *regs, struct sigcontext *sc, int *rval_p) | |
156 | { | |
157 | unsigned int err = 0; | |
158 | ||
159 | #define COPY(x) err |= __get_user(regs->x, &sc->regs.x) | |
160 | COPY(gpr[0]); COPY(gpr[1]); COPY(gpr[2]); COPY(gpr[3]); | |
161 | COPY(gpr[4]); COPY(gpr[5]); COPY(gpr[6]); COPY(gpr[7]); | |
162 | COPY(gpr[8]); COPY(gpr[9]); COPY(gpr[10]); COPY(gpr[11]); | |
163 | COPY(gpr[12]); COPY(gpr[13]); COPY(gpr[14]); COPY(gpr[15]); | |
164 | COPY(gpr[16]); COPY(gpr[17]); COPY(gpr[18]); COPY(gpr[19]); | |
165 | COPY(gpr[20]); COPY(gpr[21]); COPY(gpr[22]); COPY(gpr[23]); | |
166 | COPY(gpr[24]); COPY(gpr[25]); COPY(gpr[26]); COPY(gpr[27]); | |
167 | COPY(gpr[28]); COPY(gpr[29]); COPY(gpr[30]); COPY(gpr[31]); | |
168 | COPY(pc); COPY(psw); | |
169 | COPY(ctpc); COPY(ctpsw); COPY(ctbp); | |
170 | #undef COPY | |
171 | ||
172 | return err; | |
173 | } | |
174 | ||
175 | asmlinkage int sys_sigreturn(struct pt_regs *regs) | |
176 | { | |
177 | struct sigframe *frame = (struct sigframe *)regs->gpr[GPR_SP]; | |
178 | sigset_t set; | |
179 | int rval; | |
180 | ||
181 | if (!access_ok(VERIFY_READ, frame, sizeof(*frame))) | |
182 | goto badframe; | |
183 | ||
184 | if (__get_user(set.sig[0], &frame->sc.oldmask) | |
185 | || (_NSIG_WORDS > 1 | |
186 | && __copy_from_user(&set.sig[1], &frame->extramask, | |
187 | sizeof(frame->extramask)))) | |
188 | goto badframe; | |
189 | ||
190 | sigdelsetmask(&set, ~_BLOCKABLE); | |
191 | spin_lock_irq(¤t->sighand->siglock); | |
192 | current->blocked = set; | |
193 | recalc_sigpending(); | |
194 | spin_unlock_irq(¤t->sighand->siglock); | |
195 | ||
196 | if (restore_sigcontext(regs, &frame->sc, &rval)) | |
197 | goto badframe; | |
198 | return rval; | |
199 | ||
200 | badframe: | |
201 | force_sig(SIGSEGV, current); | |
202 | return 0; | |
203 | } | |
204 | ||
205 | asmlinkage int sys_rt_sigreturn(struct pt_regs *regs) | |
206 | { | |
207 | struct rt_sigframe *frame = (struct rt_sigframe *)regs->gpr[GPR_SP]; | |
208 | sigset_t set; | |
209 | stack_t st; | |
210 | int rval; | |
211 | ||
212 | if (!access_ok(VERIFY_READ, frame, sizeof(*frame))) | |
213 | goto badframe; | |
214 | ||
215 | if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set))) | |
216 | goto badframe; | |
217 | ||
218 | sigdelsetmask(&set, ~_BLOCKABLE); | |
219 | spin_lock_irq(¤t->sighand->siglock); | |
220 | current->blocked = set; | |
221 | recalc_sigpending(); | |
222 | spin_unlock_irq(¤t->sighand->siglock); | |
223 | ||
224 | if (restore_sigcontext(regs, &frame->uc.uc_mcontext, &rval)) | |
225 | goto badframe; | |
226 | ||
227 | if (__copy_from_user(&st, &frame->uc.uc_stack, sizeof(st))) | |
228 | goto badframe; | |
229 | /* It is more difficult to avoid calling this function than to | |
230 | call it and ignore errors. */ | |
231 | do_sigaltstack(&st, NULL, regs->gpr[GPR_SP]); | |
232 | ||
233 | return rval; | |
234 | ||
235 | badframe: | |
236 | force_sig(SIGSEGV, current); | |
237 | return 0; | |
238 | } | |
239 | ||
240 | /* | |
241 | * Set up a signal frame. | |
242 | */ | |
243 | ||
244 | static int | |
245 | setup_sigcontext(struct sigcontext *sc, struct pt_regs *regs, | |
246 | unsigned long mask) | |
247 | { | |
248 | int err = 0; | |
249 | ||
250 | #define COPY(x) err |= __put_user(regs->x, &sc->regs.x) | |
251 | COPY(gpr[0]); COPY(gpr[1]); COPY(gpr[2]); COPY(gpr[3]); | |
252 | COPY(gpr[4]); COPY(gpr[5]); COPY(gpr[6]); COPY(gpr[7]); | |
253 | COPY(gpr[8]); COPY(gpr[9]); COPY(gpr[10]); COPY(gpr[11]); | |
254 | COPY(gpr[12]); COPY(gpr[13]); COPY(gpr[14]); COPY(gpr[15]); | |
255 | COPY(gpr[16]); COPY(gpr[17]); COPY(gpr[18]); COPY(gpr[19]); | |
256 | COPY(gpr[20]); COPY(gpr[21]); COPY(gpr[22]); COPY(gpr[23]); | |
257 | COPY(gpr[24]); COPY(gpr[25]); COPY(gpr[26]); COPY(gpr[27]); | |
258 | COPY(gpr[28]); COPY(gpr[29]); COPY(gpr[30]); COPY(gpr[31]); | |
259 | COPY(pc); COPY(psw); | |
260 | COPY(ctpc); COPY(ctpsw); COPY(ctbp); | |
261 | #undef COPY | |
262 | ||
263 | err |= __put_user(mask, &sc->oldmask); | |
264 | ||
265 | return err; | |
266 | } | |
267 | ||
268 | /* | |
269 | * Determine which stack to use.. | |
270 | */ | |
271 | static inline void * | |
272 | get_sigframe(struct k_sigaction *ka, struct pt_regs *regs, size_t frame_size) | |
273 | { | |
274 | /* Default to using normal stack */ | |
275 | unsigned long sp = regs->gpr[GPR_SP]; | |
276 | ||
277 | if ((ka->sa.sa_flags & SA_ONSTACK) != 0 && ! on_sig_stack(sp)) | |
278 | sp = current->sas_ss_sp + current->sas_ss_size; | |
279 | ||
280 | return (void *)((sp - frame_size) & -8UL); | |
281 | } | |
282 | ||
283 | static void setup_frame(int sig, struct k_sigaction *ka, | |
284 | sigset_t *set, struct pt_regs *regs) | |
285 | { | |
286 | struct sigframe *frame; | |
287 | int err = 0; | |
288 | int signal; | |
289 | ||
290 | frame = get_sigframe(ka, regs, sizeof(*frame)); | |
291 | ||
292 | if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame))) | |
293 | goto give_sigsegv; | |
294 | ||
295 | signal = current_thread_info()->exec_domain | |
296 | && current_thread_info()->exec_domain->signal_invmap | |
297 | && sig < 32 | |
298 | ? current_thread_info()->exec_domain->signal_invmap[sig] | |
299 | : sig; | |
300 | ||
301 | err |= setup_sigcontext(&frame->sc, regs, set->sig[0]); | |
302 | ||
303 | if (_NSIG_WORDS > 1) { | |
304 | err |= __copy_to_user(frame->extramask, &set->sig[1], | |
305 | sizeof(frame->extramask)); | |
306 | } | |
307 | ||
308 | /* Set up to return from userspace. If provided, use a stub | |
309 | already in userspace. */ | |
310 | if (ka->sa.sa_flags & SA_RESTORER) { | |
311 | regs->gpr[GPR_LP] = (unsigned long) ka->sa.sa_restorer; | |
312 | } else { | |
313 | /* Note, these encodings are _little endian_! */ | |
314 | ||
315 | /* addi __NR_sigreturn, r0, r12 */ | |
316 | err |= __put_user(0x6600 | (__NR_sigreturn << 16), | |
317 | frame->tramp + 0); | |
318 | /* trap 0 */ | |
319 | err |= __put_user(0x010007e0, | |
320 | frame->tramp + 1); | |
321 | ||
322 | regs->gpr[GPR_LP] = (unsigned long)frame->tramp; | |
323 | ||
324 | flush_cache_sigtramp (regs->gpr[GPR_LP]); | |
325 | } | |
326 | ||
327 | if (err) | |
328 | goto give_sigsegv; | |
329 | ||
330 | /* Set up registers for signal handler. */ | |
331 | regs->pc = (v850_reg_t) ka->sa.sa_handler; | |
332 | regs->gpr[GPR_SP] = (v850_reg_t)frame; | |
333 | /* Signal handler args: */ | |
334 | regs->gpr[GPR_ARG0] = signal; /* arg 0: signum */ | |
335 | regs->gpr[GPR_ARG1] = (v850_reg_t)&frame->sc;/* arg 1: sigcontext */ | |
336 | ||
337 | set_fs(USER_DS); | |
338 | ||
339 | #if DEBUG_SIG | |
340 | printk("SIG deliver (%s:%d): sp=%p pc=%08lx ra=%08lx\n", | |
341 | current->comm, current->pid, frame, regs->pc, ); | |
342 | #endif | |
343 | ||
344 | return; | |
345 | ||
346 | give_sigsegv: | |
347 | force_sigsegv(sig, current); | |
348 | } | |
349 | ||
350 | static void setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info, | |
351 | sigset_t *set, struct pt_regs *regs) | |
352 | { | |
353 | struct rt_sigframe *frame; | |
354 | int err = 0; | |
355 | int signal; | |
356 | ||
357 | frame = get_sigframe(ka, regs, sizeof(*frame)); | |
358 | ||
359 | if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame))) | |
360 | goto give_sigsegv; | |
361 | ||
362 | signal = current_thread_info()->exec_domain | |
363 | && current_thread_info()->exec_domain->signal_invmap | |
364 | && sig < 32 | |
365 | ? current_thread_info()->exec_domain->signal_invmap[sig] | |
366 | : sig; | |
367 | ||
368 | err |= copy_siginfo_to_user(&frame->info, info); | |
369 | ||
370 | /* Create the ucontext. */ | |
371 | err |= __put_user(0, &frame->uc.uc_flags); | |
372 | err |= __put_user(0, &frame->uc.uc_link); | |
373 | err |= __put_user((void *)current->sas_ss_sp, | |
374 | &frame->uc.uc_stack.ss_sp); | |
375 | err |= __put_user(sas_ss_flags(regs->gpr[GPR_SP]), | |
376 | &frame->uc.uc_stack.ss_flags); | |
377 | err |= __put_user(current->sas_ss_size, &frame->uc.uc_stack.ss_size); | |
378 | err |= setup_sigcontext(&frame->uc.uc_mcontext, | |
379 | regs, set->sig[0]); | |
380 | err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set)); | |
381 | ||
382 | /* Set up to return from userspace. If provided, use a stub | |
383 | already in userspace. */ | |
384 | if (ka->sa.sa_flags & SA_RESTORER) { | |
385 | regs->gpr[GPR_LP] = (unsigned long) ka->sa.sa_restorer; | |
386 | } else { | |
387 | /* Note, these encodings are _little endian_! */ | |
388 | ||
389 | /* addi __NR_sigreturn, r0, r12 */ | |
390 | err |= __put_user(0x6600 | (__NR_sigreturn << 16), | |
391 | frame->tramp + 0); | |
392 | /* trap 0 */ | |
393 | err |= __put_user(0x010007e0, | |
394 | frame->tramp + 1); | |
395 | ||
396 | regs->gpr[GPR_LP] = (unsigned long)frame->tramp; | |
397 | ||
398 | flush_cache_sigtramp (regs->gpr[GPR_LP]); | |
399 | } | |
400 | ||
401 | if (err) | |
402 | goto give_sigsegv; | |
403 | ||
404 | /* Set up registers for signal handler. */ | |
405 | regs->pc = (v850_reg_t) ka->sa.sa_handler; | |
406 | regs->gpr[GPR_SP] = (v850_reg_t)frame; | |
407 | /* Signal handler args: */ | |
408 | regs->gpr[GPR_ARG0] = signal; /* arg 0: signum */ | |
409 | regs->gpr[GPR_ARG1] = (v850_reg_t)&frame->info; /* arg 1: siginfo */ | |
410 | regs->gpr[GPR_ARG2] = (v850_reg_t)&frame->uc; /* arg 2: ucontext */ | |
411 | ||
412 | set_fs(USER_DS); | |
413 | ||
414 | #if DEBUG_SIG | |
415 | printk("SIG deliver (%s:%d): sp=%p pc=%08lx pr=%08lx\n", | |
416 | current->comm, current->pid, frame, regs->pc, regs->pr); | |
417 | #endif | |
418 | ||
419 | return; | |
420 | ||
421 | give_sigsegv: | |
422 | force_sigsegv(sig, current); | |
423 | } | |
424 | ||
425 | /* | |
426 | * OK, we're invoking a handler | |
427 | */ | |
428 | ||
429 | static void | |
430 | handle_signal(unsigned long sig, siginfo_t *info, struct k_sigaction *ka, | |
431 | sigset_t *oldset, struct pt_regs * regs) | |
432 | { | |
433 | /* Are we from a system call? */ | |
434 | if (PT_REGS_SYSCALL (regs)) { | |
435 | /* If so, check system call restarting.. */ | |
436 | switch (regs->gpr[GPR_RVAL]) { | |
437 | case -ERESTART_RESTARTBLOCK: | |
438 | current_thread_info()->restart_block.fn = | |
439 | do_no_restart_syscall; | |
440 | /* fall through */ | |
441 | case -ERESTARTNOHAND: | |
442 | regs->gpr[GPR_RVAL] = -EINTR; | |
443 | break; | |
444 | ||
445 | case -ERESTARTSYS: | |
446 | if (!(ka->sa.sa_flags & SA_RESTART)) { | |
447 | regs->gpr[GPR_RVAL] = -EINTR; | |
448 | break; | |
449 | } | |
450 | /* fallthrough */ | |
451 | case -ERESTARTNOINTR: | |
452 | regs->gpr[12] = PT_REGS_SYSCALL (regs); | |
453 | regs->pc -= 4; /* Size of `trap 0' insn. */ | |
454 | } | |
455 | ||
456 | PT_REGS_SET_SYSCALL (regs, 0); | |
457 | } | |
458 | ||
459 | /* Set up the stack frame */ | |
460 | if (ka->sa.sa_flags & SA_SIGINFO) | |
461 | setup_rt_frame(sig, ka, info, oldset, regs); | |
462 | else | |
463 | setup_frame(sig, ka, oldset, regs); | |
464 | ||
69be8f18 SR |
465 | spin_lock_irq(¤t->sighand->siglock); |
466 | sigorsets(¤t->blocked,¤t->blocked,&ka->sa.sa_mask); | |
467 | if (!(ka->sa.sa_flags & SA_NODEFER)) | |
1da177e4 | 468 | sigaddset(¤t->blocked,sig); |
69be8f18 SR |
469 | recalc_sigpending(); |
470 | spin_unlock_irq(¤t->sighand->siglock); | |
1da177e4 LT |
471 | } |
472 | ||
473 | /* | |
474 | * Note that 'init' is a special process: it doesn't get signals it doesn't | |
475 | * want to handle. Thus you cannot kill init even with a SIGKILL even by | |
476 | * mistake. | |
477 | * | |
478 | * Note that we go through the signals twice: once to check the signals that | |
479 | * the kernel can handle, and then we build all the user-level signal handling | |
480 | * stack-frames in one go after that. | |
481 | */ | |
482 | int do_signal(struct pt_regs *regs, sigset_t *oldset) | |
483 | { | |
484 | siginfo_t info; | |
485 | int signr; | |
486 | struct k_sigaction ka; | |
487 | ||
488 | /* | |
489 | * We want the common case to go fast, which | |
490 | * is why we may in certain cases get here from | |
491 | * kernel mode. Just return without doing anything | |
492 | * if so. | |
493 | */ | |
494 | if (!user_mode(regs)) | |
495 | return 1; | |
496 | ||
497 | if (!oldset) | |
498 | oldset = ¤t->blocked; | |
499 | ||
500 | signr = get_signal_to_deliver(&info, &ka, regs, NULL); | |
501 | if (signr > 0) { | |
502 | /* Whee! Actually deliver the signal. */ | |
503 | handle_signal(signr, &info, &ka, oldset, regs); | |
504 | return 1; | |
505 | } | |
506 | ||
507 | /* Did we come from a system call? */ | |
508 | if (PT_REGS_SYSCALL (regs)) { | |
509 | int rval = (int)regs->gpr[GPR_RVAL]; | |
510 | /* Restart the system call - no handlers present */ | |
511 | if (rval == -ERESTARTNOHAND | |
512 | || rval == -ERESTARTSYS | |
513 | || rval == -ERESTARTNOINTR) | |
514 | { | |
515 | regs->gpr[12] = PT_REGS_SYSCALL (regs); | |
516 | regs->pc -= 4; /* Size of `trap 0' insn. */ | |
517 | } | |
518 | else if (rval == -ERESTART_RESTARTBLOCK) { | |
519 | regs->gpr[12] = __NR_restart_syscall; | |
520 | regs->pc -= 4; /* Size of `trap 0' insn. */ | |
521 | } | |
522 | } | |
523 | return 0; | |
524 | } |