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1/*
2 * This file is subject to the terms and conditions of the GNU General Public
3 * License. See the file "COPYING" in the main directory of this archive
4 * for more details.
5 *
6 * Copyright (C) 1991, 1992 Linus Torvalds
7 * Copyright (C) 1994 - 2000 Ralf Baechle
8 * Copyright (C) 1999, 2000 Silicon Graphics, Inc.
9 */
10#include <linux/cache.h>
11#include <linux/irqflags.h>
12#include <linux/sched.h>
13#include <linux/mm.h>
14#include <linux/personality.h>
15#include <linux/smp.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/compiler.h>
23#include <linux/syscalls.h>
24#include <linux/uaccess.h>
25#include <linux/tracehook.h>
26
27#include <asm/abi.h>
28#include <asm/asm.h>
29#include <linux/bitops.h>
30#include <asm/cacheflush.h>
31#include <asm/fpu.h>
32#include <asm/sim.h>
33#include <asm/ucontext.h>
34#include <asm/cpu-features.h>
35#include <asm/war.h>
36#include <asm/vdso.h>
37#include <asm/dsp.h>
38
39#include "signal-common.h"
40
41static int (*save_fp_context)(struct sigcontext __user *sc);
42static int (*restore_fp_context)(struct sigcontext __user *sc);
43
44extern asmlinkage int _save_fp_context(struct sigcontext __user *sc);
45extern asmlinkage int _restore_fp_context(struct sigcontext __user *sc);
46
47extern asmlinkage int fpu_emulator_save_context(struct sigcontext __user *sc);
48extern asmlinkage int fpu_emulator_restore_context(struct sigcontext __user *sc);
49
50struct sigframe {
51 u32 sf_ass[4]; /* argument save space for o32 */
52 u32 sf_pad[2]; /* Was: signal trampoline */
53 struct sigcontext sf_sc;
54 sigset_t sf_mask;
55};
56
57struct rt_sigframe {
58 u32 rs_ass[4]; /* argument save space for o32 */
59 u32 rs_pad[2]; /* Was: signal trampoline */
60 struct siginfo rs_info;
61 struct ucontext rs_uc;
62};
63
64/*
65 * Helper routines
66 */
67static int protected_save_fp_context(struct sigcontext __user *sc)
68{
69 int err;
70 while (1) {
71 lock_fpu_owner();
72 own_fpu_inatomic(1);
73 err = save_fp_context(sc); /* this might fail */
74 unlock_fpu_owner();
75 if (likely(!err))
76 break;
77 /* touch the sigcontext and try again */
78 err = __put_user(0, &sc->sc_fpregs[0]) |
79 __put_user(0, &sc->sc_fpregs[31]) |
80 __put_user(0, &sc->sc_fpc_csr);
81 if (err)
82 break; /* really bad sigcontext */
83 }
84 return err;
85}
86
87static int protected_restore_fp_context(struct sigcontext __user *sc)
88{
89 int err, tmp __maybe_unused;
90 while (1) {
91 lock_fpu_owner();
92 own_fpu_inatomic(0);
93 err = restore_fp_context(sc); /* this might fail */
94 unlock_fpu_owner();
95 if (likely(!err))
96 break;
97 /* touch the sigcontext and try again */
98 err = __get_user(tmp, &sc->sc_fpregs[0]) |
99 __get_user(tmp, &sc->sc_fpregs[31]) |
100 __get_user(tmp, &sc->sc_fpc_csr);
101 if (err)
102 break; /* really bad sigcontext */
103 }
104 return err;
105}
106
107int setup_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc)
108{
109 int err = 0;
110 int i;
111 unsigned int used_math;
112
113 err |= __put_user(regs->cp0_epc, &sc->sc_pc);
114
115 err |= __put_user(0, &sc->sc_regs[0]);
116 for (i = 1; i < 32; i++)
117 err |= __put_user(regs->regs[i], &sc->sc_regs[i]);
118
119#ifdef CONFIG_CPU_HAS_SMARTMIPS
120 err |= __put_user(regs->acx, &sc->sc_acx);
121#endif
122 err |= __put_user(regs->hi, &sc->sc_mdhi);
123 err |= __put_user(regs->lo, &sc->sc_mdlo);
124 if (cpu_has_dsp) {
125 err |= __put_user(mfhi1(), &sc->sc_hi1);
126 err |= __put_user(mflo1(), &sc->sc_lo1);
127 err |= __put_user(mfhi2(), &sc->sc_hi2);
128 err |= __put_user(mflo2(), &sc->sc_lo2);
129 err |= __put_user(mfhi3(), &sc->sc_hi3);
130 err |= __put_user(mflo3(), &sc->sc_lo3);
131 err |= __put_user(rddsp(DSP_MASK), &sc->sc_dsp);
132 }
133
134 used_math = !!used_math();
135 err |= __put_user(used_math, &sc->sc_used_math);
136
137 if (used_math) {
138 /*
139 * Save FPU state to signal context. Signal handler
140 * will "inherit" current FPU state.
141 */
142 err |= protected_save_fp_context(sc);
143 }
144 return err;
145}
146
147int fpcsr_pending(unsigned int __user *fpcsr)
148{
149 int err, sig = 0;
150 unsigned int csr, enabled;
151
152 err = __get_user(csr, fpcsr);
153 enabled = FPU_CSR_UNI_X | ((csr & FPU_CSR_ALL_E) << 5);
154 /*
155 * If the signal handler set some FPU exceptions, clear it and
156 * send SIGFPE.
157 */
158 if (csr & enabled) {
159 csr &= ~enabled;
160 err |= __put_user(csr, fpcsr);
161 sig = SIGFPE;
162 }
163 return err ?: sig;
164}
165
166static int
167check_and_restore_fp_context(struct sigcontext __user *sc)
168{
169 int err, sig;
170
171 err = sig = fpcsr_pending(&sc->sc_fpc_csr);
172 if (err > 0)
173 err = 0;
174 err |= protected_restore_fp_context(sc);
175 return err ?: sig;
176}
177
178int restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc)
179{
180 unsigned int used_math;
181 unsigned long treg;
182 int err = 0;
183 int i;
184
185 /* Always make any pending restarted system calls return -EINTR */
186 current_thread_info()->restart_block.fn = do_no_restart_syscall;
187
188 err |= __get_user(regs->cp0_epc, &sc->sc_pc);
189
190#ifdef CONFIG_CPU_HAS_SMARTMIPS
191 err |= __get_user(regs->acx, &sc->sc_acx);
192#endif
193 err |= __get_user(regs->hi, &sc->sc_mdhi);
194 err |= __get_user(regs->lo, &sc->sc_mdlo);
195 if (cpu_has_dsp) {
196 err |= __get_user(treg, &sc->sc_hi1); mthi1(treg);
197 err |= __get_user(treg, &sc->sc_lo1); mtlo1(treg);
198 err |= __get_user(treg, &sc->sc_hi2); mthi2(treg);
199 err |= __get_user(treg, &sc->sc_lo2); mtlo2(treg);
200 err |= __get_user(treg, &sc->sc_hi3); mthi3(treg);
201 err |= __get_user(treg, &sc->sc_lo3); mtlo3(treg);
202 err |= __get_user(treg, &sc->sc_dsp); wrdsp(treg, DSP_MASK);
203 }
204
205 for (i = 1; i < 32; i++)
206 err |= __get_user(regs->regs[i], &sc->sc_regs[i]);
207
208 err |= __get_user(used_math, &sc->sc_used_math);
209 conditional_used_math(used_math);
210
211 if (used_math) {
212 /* restore fpu context if we have used it before */
213 if (!err)
214 err = check_and_restore_fp_context(sc);
215 } else {
216 /* signal handler may have used FPU. Give it up. */
217 lose_fpu(0);
218 }
219
220 return err;
221}
222
223void __user *get_sigframe(struct k_sigaction *ka, struct pt_regs *regs,
224 size_t frame_size)
225{
226 unsigned long sp;
227
228 /* Default to using normal stack */
229 sp = regs->regs[29];
230
231 /*
232 * FPU emulator may have it's own trampoline active just
233 * above the user stack, 16-bytes before the next lowest
234 * 16 byte boundary. Try to avoid trashing it.
235 */
236 sp -= 32;
237
238 /* This is the X/Open sanctioned signal stack switching. */
239 if ((ka->sa.sa_flags & SA_ONSTACK) && (sas_ss_flags (sp) == 0))
240 sp = current->sas_ss_sp + current->sas_ss_size;
241
242 return (void __user *)((sp - frame_size) & (ICACHE_REFILLS_WORKAROUND_WAR ? ~(cpu_icache_line_size()-1) : ALMASK));
243}
244
245/*
246 * Atomically swap in the new signal mask, and wait for a signal.
247 */
248
249#ifdef CONFIG_TRAD_SIGNALS
250asmlinkage int sys_sigsuspend(nabi_no_regargs struct pt_regs regs)
251{
252 sigset_t newset;
253 sigset_t __user *uset;
254
255 uset = (sigset_t __user *) regs.regs[4];
256 if (copy_from_user(&newset, uset, sizeof(sigset_t)))
257 return -EFAULT;
258 return sigsuspend(&newset);
259}
260#endif
261
262asmlinkage int sys_rt_sigsuspend(nabi_no_regargs struct pt_regs regs)
263{
264 sigset_t newset;
265 sigset_t __user *unewset;
266 size_t sigsetsize;
267
268 /* XXX Don't preclude handling different sized sigset_t's. */
269 sigsetsize = regs.regs[5];
270 if (sigsetsize != sizeof(sigset_t))
271 return -EINVAL;
272
273 unewset = (sigset_t __user *) regs.regs[4];
274 if (copy_from_user(&newset, unewset, sizeof(newset)))
275 return -EFAULT;
276 return sigsuspend(&newset);
277}
278
279#ifdef CONFIG_TRAD_SIGNALS
280SYSCALL_DEFINE3(sigaction, int, sig, const struct sigaction __user *, act,
281 struct sigaction __user *, oact)
282{
283 struct k_sigaction new_ka, old_ka;
284 int ret;
285 int err = 0;
286
287 if (act) {
288 old_sigset_t mask;
289
290 if (!access_ok(VERIFY_READ, act, sizeof(*act)))
291 return -EFAULT;
292 err |= __get_user(new_ka.sa.sa_handler, &act->sa_handler);
293 err |= __get_user(new_ka.sa.sa_flags, &act->sa_flags);
294 err |= __get_user(mask, &act->sa_mask.sig[0]);
295 if (err)
296 return -EFAULT;
297
298 siginitset(&new_ka.sa.sa_mask, mask);
299 }
300
301 ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL);
302
303 if (!ret && oact) {
304 if (!access_ok(VERIFY_WRITE, oact, sizeof(*oact)))
305 return -EFAULT;
306 err |= __put_user(old_ka.sa.sa_flags, &oact->sa_flags);
307 err |= __put_user(old_ka.sa.sa_handler, &oact->sa_handler);
308 err |= __put_user(old_ka.sa.sa_mask.sig[0], oact->sa_mask.sig);
309 err |= __put_user(0, &oact->sa_mask.sig[1]);
310 err |= __put_user(0, &oact->sa_mask.sig[2]);
311 err |= __put_user(0, &oact->sa_mask.sig[3]);
312 if (err)
313 return -EFAULT;
314 }
315
316 return ret;
317}
318#endif
319
320asmlinkage int sys_sigaltstack(nabi_no_regargs struct pt_regs regs)
321{
322 const stack_t __user *uss = (const stack_t __user *) regs.regs[4];
323 stack_t __user *uoss = (stack_t __user *) regs.regs[5];
324 unsigned long usp = regs.regs[29];
325
326 return do_sigaltstack(uss, uoss, usp);
327}
328
329#ifdef CONFIG_TRAD_SIGNALS
330asmlinkage void sys_sigreturn(nabi_no_regargs struct pt_regs regs)
331{
332 struct sigframe __user *frame;
333 sigset_t blocked;
334 int sig;
335
336 frame = (struct sigframe __user *) regs.regs[29];
337 if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
338 goto badframe;
339 if (__copy_from_user(&blocked, &frame->sf_mask, sizeof(blocked)))
340 goto badframe;
341
342 set_current_blocked(&blocked);
343
344 sig = restore_sigcontext(®s, &frame->sf_sc);
345 if (sig < 0)
346 goto badframe;
347 else if (sig)
348 force_sig(sig, current);
349
350 /*
351 * Don't let your children do this ...
352 */
353 __asm__ __volatile__(
354 "move\t$29, %0\n\t"
355 "j\tsyscall_exit"
356 :/* no outputs */
357 :"r" (®s));
358 /* Unreached */
359
360badframe:
361 force_sig(SIGSEGV, current);
362}
363#endif /* CONFIG_TRAD_SIGNALS */
364
365asmlinkage void sys_rt_sigreturn(nabi_no_regargs struct pt_regs regs)
366{
367 struct rt_sigframe __user *frame;
368 sigset_t set;
369 int sig;
370
371 frame = (struct rt_sigframe __user *) regs.regs[29];
372 if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
373 goto badframe;
374 if (__copy_from_user(&set, &frame->rs_uc.uc_sigmask, sizeof(set)))
375 goto badframe;
376
377 set_current_blocked(&set);
378
379 sig = restore_sigcontext(®s, &frame->rs_uc.uc_mcontext);
380 if (sig < 0)
381 goto badframe;
382 else if (sig)
383 force_sig(sig, current);
384
385 /* It is more difficult to avoid calling this function than to
386 call it and ignore errors. */
387 do_sigaltstack(&frame->rs_uc.uc_stack, NULL, regs.regs[29]);
388
389 /*
390 * Don't let your children do this ...
391 */
392 __asm__ __volatile__(
393 "move\t$29, %0\n\t"
394 "j\tsyscall_exit"
395 :/* no outputs */
396 :"r" (®s));
397 /* Unreached */
398
399badframe:
400 force_sig(SIGSEGV, current);
401}
402
403#ifdef CONFIG_TRAD_SIGNALS
404static int setup_frame(void *sig_return, struct k_sigaction *ka,
405 struct pt_regs *regs, int signr, sigset_t *set)
406{
407 struct sigframe __user *frame;
408 int err = 0;
409
410 frame = get_sigframe(ka, regs, sizeof(*frame));
411 if (!access_ok(VERIFY_WRITE, frame, sizeof (*frame)))
412 goto give_sigsegv;
413
414 err |= setup_sigcontext(regs, &frame->sf_sc);
415 err |= __copy_to_user(&frame->sf_mask, set, sizeof(*set));
416 if (err)
417 goto give_sigsegv;
418
419 /*
420 * Arguments to signal handler:
421 *
422 * a0 = signal number
423 * a1 = 0 (should be cause)
424 * a2 = pointer to struct sigcontext
425 *
426 * $25 and c0_epc point to the signal handler, $29 points to the
427 * struct sigframe.
428 */
429 regs->regs[ 4] = signr;
430 regs->regs[ 5] = 0;
431 regs->regs[ 6] = (unsigned long) &frame->sf_sc;
432 regs->regs[29] = (unsigned long) frame;
433 regs->regs[31] = (unsigned long) sig_return;
434 regs->cp0_epc = regs->regs[25] = (unsigned long) ka->sa.sa_handler;
435
436 DEBUGP("SIG deliver (%s:%d): sp=0x%p pc=0x%lx ra=0x%lx\n",
437 current->comm, current->pid,
438 frame, regs->cp0_epc, regs->regs[31]);
439 return 0;
440
441give_sigsegv:
442 force_sigsegv(signr, current);
443 return -EFAULT;
444}
445#endif
446
447static int setup_rt_frame(void *sig_return, struct k_sigaction *ka,
448 struct pt_regs *regs, int signr, sigset_t *set,
449 siginfo_t *info)
450{
451 struct rt_sigframe __user *frame;
452 int err = 0;
453
454 frame = get_sigframe(ka, regs, sizeof(*frame));
455 if (!access_ok(VERIFY_WRITE, frame, sizeof (*frame)))
456 goto give_sigsegv;
457
458 /* Create siginfo. */
459 err |= copy_siginfo_to_user(&frame->rs_info, info);
460
461 /* Create the ucontext. */
462 err |= __put_user(0, &frame->rs_uc.uc_flags);
463 err |= __put_user(NULL, &frame->rs_uc.uc_link);
464 err |= __put_user((void __user *)current->sas_ss_sp,
465 &frame->rs_uc.uc_stack.ss_sp);
466 err |= __put_user(sas_ss_flags(regs->regs[29]),
467 &frame->rs_uc.uc_stack.ss_flags);
468 err |= __put_user(current->sas_ss_size,
469 &frame->rs_uc.uc_stack.ss_size);
470 err |= setup_sigcontext(regs, &frame->rs_uc.uc_mcontext);
471 err |= __copy_to_user(&frame->rs_uc.uc_sigmask, set, sizeof(*set));
472
473 if (err)
474 goto give_sigsegv;
475
476 /*
477 * Arguments to signal handler:
478 *
479 * a0 = signal number
480 * a1 = 0 (should be cause)
481 * a2 = pointer to ucontext
482 *
483 * $25 and c0_epc point to the signal handler, $29 points to
484 * the struct rt_sigframe.
485 */
486 regs->regs[ 4] = signr;
487 regs->regs[ 5] = (unsigned long) &frame->rs_info;
488 regs->regs[ 6] = (unsigned long) &frame->rs_uc;
489 regs->regs[29] = (unsigned long) frame;
490 regs->regs[31] = (unsigned long) sig_return;
491 regs->cp0_epc = regs->regs[25] = (unsigned long) ka->sa.sa_handler;
492
493 DEBUGP("SIG deliver (%s:%d): sp=0x%p pc=0x%lx ra=0x%lx\n",
494 current->comm, current->pid,
495 frame, regs->cp0_epc, regs->regs[31]);
496
497 return 0;
498
499give_sigsegv:
500 force_sigsegv(signr, current);
501 return -EFAULT;
502}
503
504struct mips_abi mips_abi = {
505#ifdef CONFIG_TRAD_SIGNALS
506 .setup_frame = setup_frame,
507 .signal_return_offset = offsetof(struct mips_vdso, signal_trampoline),
508#endif
509 .setup_rt_frame = setup_rt_frame,
510 .rt_signal_return_offset =
511 offsetof(struct mips_vdso, rt_signal_trampoline),
512 .restart = __NR_restart_syscall
513};
514
515static void handle_signal(unsigned long sig, siginfo_t *info,
516 struct k_sigaction *ka, struct pt_regs *regs)
517{
518 sigset_t *oldset = sigmask_to_save();
519 int ret;
520 struct mips_abi *abi = current->thread.abi;
521 void *vdso = current->mm->context.vdso;
522
523 if (regs->regs[0]) {
524 switch(regs->regs[2]) {
525 case ERESTART_RESTARTBLOCK:
526 case ERESTARTNOHAND:
527 regs->regs[2] = EINTR;
528 break;
529 case ERESTARTSYS:
530 if (!(ka->sa.sa_flags & SA_RESTART)) {
531 regs->regs[2] = EINTR;
532 break;
533 }
534 /* fallthrough */
535 case ERESTARTNOINTR:
536 regs->regs[7] = regs->regs[26];
537 regs->regs[2] = regs->regs[0];
538 regs->cp0_epc -= 4;
539 }
540
541 regs->regs[0] = 0; /* Don't deal with this again. */
542 }
543
544 if (sig_uses_siginfo(ka))
545 ret = abi->setup_rt_frame(vdso + abi->rt_signal_return_offset,
546 ka, regs, sig, oldset, info);
547 else
548 ret = abi->setup_frame(vdso + abi->signal_return_offset,
549 ka, regs, sig, oldset);
550
551 if (ret)
552 return;
553
554 signal_delivered(sig, info, ka, regs, 0);
555}
556
557static void do_signal(struct pt_regs *regs)
558{
559 struct k_sigaction ka;
560 siginfo_t info;
561 int signr;
562
563 /*
564 * We want the common case to go fast, which is why we may in certain
565 * cases get here from kernel mode. Just return without doing anything
566 * if so.
567 */
568 if (!user_mode(regs))
569 return;
570
571 signr = get_signal_to_deliver(&info, &ka, regs, NULL);
572 if (signr > 0) {
573 /* Whee! Actually deliver the signal. */
574 handle_signal(signr, &info, &ka, regs);
575 return;
576 }
577
578 if (regs->regs[0]) {
579 if (regs->regs[2] == ERESTARTNOHAND ||
580 regs->regs[2] == ERESTARTSYS ||
581 regs->regs[2] == ERESTARTNOINTR) {
582 regs->regs[2] = regs->regs[0];
583 regs->regs[7] = regs->regs[26];
584 regs->cp0_epc -= 4;
585 }
586 if (regs->regs[2] == ERESTART_RESTARTBLOCK) {
587 regs->regs[2] = current->thread.abi->restart;
588 regs->regs[7] = regs->regs[26];
589 regs->cp0_epc -= 4;
590 }
591 regs->regs[0] = 0; /* Don't deal with this again. */
592 }
593
594 /*
595 * If there's no signal to deliver, we just put the saved sigmask
596 * back
597 */
598 restore_saved_sigmask();
599}
600
601/*
602 * notification of userspace execution resumption
603 * - triggered by the TIF_WORK_MASK flags
604 */
605asmlinkage void do_notify_resume(struct pt_regs *regs, void *unused,
606 __u32 thread_info_flags)
607{
608 local_irq_enable();
609
610 /* deal with pending signal delivery */
611 if (thread_info_flags & _TIF_SIGPENDING)
612 do_signal(regs);
613
614 if (thread_info_flags & _TIF_NOTIFY_RESUME) {
615 clear_thread_flag(TIF_NOTIFY_RESUME);
616 tracehook_notify_resume(regs);
617 }
618}
619
620#ifdef CONFIG_SMP
621static int smp_save_fp_context(struct sigcontext __user *sc)
622{
623 return raw_cpu_has_fpu
624 ? _save_fp_context(sc)
625 : fpu_emulator_save_context(sc);
626}
627
628static int smp_restore_fp_context(struct sigcontext __user *sc)
629{
630 return raw_cpu_has_fpu
631 ? _restore_fp_context(sc)
632 : fpu_emulator_restore_context(sc);
633}
634#endif
635
636static int signal_setup(void)
637{
638#ifdef CONFIG_SMP
639 /* For now just do the cpu_has_fpu check when the functions are invoked */
640 save_fp_context = smp_save_fp_context;
641 restore_fp_context = smp_restore_fp_context;
642#else
643 if (cpu_has_fpu) {
644 save_fp_context = _save_fp_context;
645 restore_fp_context = _restore_fp_context;
646 } else {
647 save_fp_context = fpu_emulator_save_context;
648 restore_fp_context = fpu_emulator_restore_context;
649 }
650#endif
651
652 return 0;
653}
654
655arch_initcall(signal_setup);
1/*
2 * This file is subject to the terms and conditions of the GNU General Public
3 * License. See the file "COPYING" in the main directory of this archive
4 * for more details.
5 *
6 * Copyright (C) 1991, 1992 Linus Torvalds
7 * Copyright (C) 1994 - 2000 Ralf Baechle
8 * Copyright (C) 1999, 2000 Silicon Graphics, Inc.
9 * Copyright (C) 2014, Imagination Technologies Ltd.
10 */
11#include <linux/cache.h>
12#include <linux/context_tracking.h>
13#include <linux/irqflags.h>
14#include <linux/sched.h>
15#include <linux/mm.h>
16#include <linux/personality.h>
17#include <linux/smp.h>
18#include <linux/kernel.h>
19#include <linux/signal.h>
20#include <linux/errno.h>
21#include <linux/wait.h>
22#include <linux/ptrace.h>
23#include <linux/unistd.h>
24#include <linux/compiler.h>
25#include <linux/syscalls.h>
26#include <linux/uaccess.h>
27#include <linux/tracehook.h>
28
29#include <asm/abi.h>
30#include <asm/asm.h>
31#include <linux/bitops.h>
32#include <asm/cacheflush.h>
33#include <asm/fpu.h>
34#include <asm/msa.h>
35#include <asm/sim.h>
36#include <asm/ucontext.h>
37#include <asm/cpu-features.h>
38#include <asm/war.h>
39#include <asm/vdso.h>
40#include <asm/dsp.h>
41#include <asm/inst.h>
42
43#include "signal-common.h"
44
45static int (*save_fp_context)(struct sigcontext __user *sc);
46static int (*restore_fp_context)(struct sigcontext __user *sc);
47
48extern asmlinkage int _save_fp_context(struct sigcontext __user *sc);
49extern asmlinkage int _restore_fp_context(struct sigcontext __user *sc);
50
51extern asmlinkage int _save_msa_context(struct sigcontext __user *sc);
52extern asmlinkage int _restore_msa_context(struct sigcontext __user *sc);
53
54struct sigframe {
55 u32 sf_ass[4]; /* argument save space for o32 */
56 u32 sf_pad[2]; /* Was: signal trampoline */
57 struct sigcontext sf_sc;
58 sigset_t sf_mask;
59};
60
61struct rt_sigframe {
62 u32 rs_ass[4]; /* argument save space for o32 */
63 u32 rs_pad[2]; /* Was: signal trampoline */
64 struct siginfo rs_info;
65 struct ucontext rs_uc;
66};
67
68/*
69 * Thread saved context copy to/from a signal context presumed to be on the
70 * user stack, and therefore accessed with appropriate macros from uaccess.h.
71 */
72static int copy_fp_to_sigcontext(struct sigcontext __user *sc)
73{
74 int i;
75 int err = 0;
76
77 for (i = 0; i < NUM_FPU_REGS; i++) {
78 err |=
79 __put_user(get_fpr64(¤t->thread.fpu.fpr[i], 0),
80 &sc->sc_fpregs[i]);
81 }
82 err |= __put_user(current->thread.fpu.fcr31, &sc->sc_fpc_csr);
83
84 return err;
85}
86
87static int copy_fp_from_sigcontext(struct sigcontext __user *sc)
88{
89 int i;
90 int err = 0;
91 u64 fpr_val;
92
93 for (i = 0; i < NUM_FPU_REGS; i++) {
94 err |= __get_user(fpr_val, &sc->sc_fpregs[i]);
95 set_fpr64(¤t->thread.fpu.fpr[i], 0, fpr_val);
96 }
97 err |= __get_user(current->thread.fpu.fcr31, &sc->sc_fpc_csr);
98
99 return err;
100}
101
102/*
103 * These functions will save only the upper 64 bits of the vector registers,
104 * since the lower 64 bits have already been saved as the scalar FP context.
105 */
106static int copy_msa_to_sigcontext(struct sigcontext __user *sc)
107{
108 int i;
109 int err = 0;
110
111 for (i = 0; i < NUM_FPU_REGS; i++) {
112 err |=
113 __put_user(get_fpr64(¤t->thread.fpu.fpr[i], 1),
114 &sc->sc_msaregs[i]);
115 }
116 err |= __put_user(current->thread.fpu.msacsr, &sc->sc_msa_csr);
117
118 return err;
119}
120
121static int copy_msa_from_sigcontext(struct sigcontext __user *sc)
122{
123 int i;
124 int err = 0;
125 u64 val;
126
127 for (i = 0; i < NUM_FPU_REGS; i++) {
128 err |= __get_user(val, &sc->sc_msaregs[i]);
129 set_fpr64(¤t->thread.fpu.fpr[i], 1, val);
130 }
131 err |= __get_user(current->thread.fpu.msacsr, &sc->sc_msa_csr);
132
133 return err;
134}
135
136/*
137 * Helper routines
138 */
139static int protected_save_fp_context(struct sigcontext __user *sc,
140 unsigned used_math)
141{
142 int err;
143 bool save_msa = cpu_has_msa && (used_math & USEDMATH_MSA);
144#ifndef CONFIG_EVA
145 while (1) {
146 lock_fpu_owner();
147 if (is_fpu_owner()) {
148 err = save_fp_context(sc);
149 if (save_msa && !err)
150 err = _save_msa_context(sc);
151 unlock_fpu_owner();
152 } else {
153 unlock_fpu_owner();
154 err = copy_fp_to_sigcontext(sc);
155 if (save_msa && !err)
156 err = copy_msa_to_sigcontext(sc);
157 }
158 if (likely(!err))
159 break;
160 /* touch the sigcontext and try again */
161 err = __put_user(0, &sc->sc_fpregs[0]) |
162 __put_user(0, &sc->sc_fpregs[31]) |
163 __put_user(0, &sc->sc_fpc_csr);
164 if (err)
165 break; /* really bad sigcontext */
166 }
167#else
168 /*
169 * EVA does not have FPU EVA instructions so saving fpu context directly
170 * does not work.
171 */
172 disable_msa();
173 lose_fpu(1);
174 err = save_fp_context(sc); /* this might fail */
175 if (save_msa && !err)
176 err = copy_msa_to_sigcontext(sc);
177#endif
178 return err;
179}
180
181static int protected_restore_fp_context(struct sigcontext __user *sc,
182 unsigned used_math)
183{
184 int err, tmp __maybe_unused;
185 bool restore_msa = cpu_has_msa && (used_math & USEDMATH_MSA);
186#ifndef CONFIG_EVA
187 while (1) {
188 lock_fpu_owner();
189 if (is_fpu_owner()) {
190 err = restore_fp_context(sc);
191 if (restore_msa && !err) {
192 enable_msa();
193 err = _restore_msa_context(sc);
194 } else {
195 /* signal handler may have used MSA */
196 disable_msa();
197 }
198 unlock_fpu_owner();
199 } else {
200 unlock_fpu_owner();
201 err = copy_fp_from_sigcontext(sc);
202 if (!err && (used_math & USEDMATH_MSA))
203 err = copy_msa_from_sigcontext(sc);
204 }
205 if (likely(!err))
206 break;
207 /* touch the sigcontext and try again */
208 err = __get_user(tmp, &sc->sc_fpregs[0]) |
209 __get_user(tmp, &sc->sc_fpregs[31]) |
210 __get_user(tmp, &sc->sc_fpc_csr);
211 if (err)
212 break; /* really bad sigcontext */
213 }
214#else
215 /*
216 * EVA does not have FPU EVA instructions so restoring fpu context
217 * directly does not work.
218 */
219 enable_msa();
220 lose_fpu(0);
221 err = restore_fp_context(sc); /* this might fail */
222 if (restore_msa && !err)
223 err = copy_msa_from_sigcontext(sc);
224#endif
225 return err;
226}
227
228int setup_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc)
229{
230 int err = 0;
231 int i;
232 unsigned int used_math;
233
234 err |= __put_user(regs->cp0_epc, &sc->sc_pc);
235
236 err |= __put_user(0, &sc->sc_regs[0]);
237 for (i = 1; i < 32; i++)
238 err |= __put_user(regs->regs[i], &sc->sc_regs[i]);
239
240#ifdef CONFIG_CPU_HAS_SMARTMIPS
241 err |= __put_user(regs->acx, &sc->sc_acx);
242#endif
243 err |= __put_user(regs->hi, &sc->sc_mdhi);
244 err |= __put_user(regs->lo, &sc->sc_mdlo);
245 if (cpu_has_dsp) {
246 err |= __put_user(mfhi1(), &sc->sc_hi1);
247 err |= __put_user(mflo1(), &sc->sc_lo1);
248 err |= __put_user(mfhi2(), &sc->sc_hi2);
249 err |= __put_user(mflo2(), &sc->sc_lo2);
250 err |= __put_user(mfhi3(), &sc->sc_hi3);
251 err |= __put_user(mflo3(), &sc->sc_lo3);
252 err |= __put_user(rddsp(DSP_MASK), &sc->sc_dsp);
253 }
254
255 used_math = used_math() ? USEDMATH_FP : 0;
256 used_math |= thread_msa_context_live() ? USEDMATH_MSA : 0;
257 err |= __put_user(used_math, &sc->sc_used_math);
258
259 if (used_math) {
260 /*
261 * Save FPU state to signal context. Signal handler
262 * will "inherit" current FPU state.
263 */
264 err |= protected_save_fp_context(sc, used_math);
265 }
266 return err;
267}
268
269int fpcsr_pending(unsigned int __user *fpcsr)
270{
271 int err, sig = 0;
272 unsigned int csr, enabled;
273
274 err = __get_user(csr, fpcsr);
275 enabled = FPU_CSR_UNI_X | ((csr & FPU_CSR_ALL_E) << 5);
276 /*
277 * If the signal handler set some FPU exceptions, clear it and
278 * send SIGFPE.
279 */
280 if (csr & enabled) {
281 csr &= ~enabled;
282 err |= __put_user(csr, fpcsr);
283 sig = SIGFPE;
284 }
285 return err ?: sig;
286}
287
288static int
289check_and_restore_fp_context(struct sigcontext __user *sc, unsigned used_math)
290{
291 int err, sig;
292
293 err = sig = fpcsr_pending(&sc->sc_fpc_csr);
294 if (err > 0)
295 err = 0;
296 err |= protected_restore_fp_context(sc, used_math);
297 return err ?: sig;
298}
299
300int restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc)
301{
302 unsigned int used_math;
303 unsigned long treg;
304 int err = 0;
305 int i;
306
307 /* Always make any pending restarted system calls return -EINTR */
308 current_thread_info()->restart_block.fn = do_no_restart_syscall;
309
310 err |= __get_user(regs->cp0_epc, &sc->sc_pc);
311
312#ifdef CONFIG_CPU_HAS_SMARTMIPS
313 err |= __get_user(regs->acx, &sc->sc_acx);
314#endif
315 err |= __get_user(regs->hi, &sc->sc_mdhi);
316 err |= __get_user(regs->lo, &sc->sc_mdlo);
317 if (cpu_has_dsp) {
318 err |= __get_user(treg, &sc->sc_hi1); mthi1(treg);
319 err |= __get_user(treg, &sc->sc_lo1); mtlo1(treg);
320 err |= __get_user(treg, &sc->sc_hi2); mthi2(treg);
321 err |= __get_user(treg, &sc->sc_lo2); mtlo2(treg);
322 err |= __get_user(treg, &sc->sc_hi3); mthi3(treg);
323 err |= __get_user(treg, &sc->sc_lo3); mtlo3(treg);
324 err |= __get_user(treg, &sc->sc_dsp); wrdsp(treg, DSP_MASK);
325 }
326
327 for (i = 1; i < 32; i++)
328 err |= __get_user(regs->regs[i], &sc->sc_regs[i]);
329
330 err |= __get_user(used_math, &sc->sc_used_math);
331 conditional_used_math(used_math);
332
333 if (used_math) {
334 /* restore fpu context if we have used it before */
335 if (!err)
336 err = check_and_restore_fp_context(sc, used_math);
337 } else {
338 /* signal handler may have used FPU or MSA. Disable them. */
339 disable_msa();
340 lose_fpu(0);
341 }
342
343 return err;
344}
345
346void __user *get_sigframe(struct k_sigaction *ka, struct pt_regs *regs,
347 size_t frame_size)
348{
349 unsigned long sp;
350
351 /* Default to using normal stack */
352 sp = regs->regs[29];
353
354 /*
355 * FPU emulator may have it's own trampoline active just
356 * above the user stack, 16-bytes before the next lowest
357 * 16 byte boundary. Try to avoid trashing it.
358 */
359 sp -= 32;
360
361 /* This is the X/Open sanctioned signal stack switching. */
362 if ((ka->sa.sa_flags & SA_ONSTACK) && (sas_ss_flags (sp) == 0))
363 sp = current->sas_ss_sp + current->sas_ss_size;
364
365 return (void __user *)((sp - frame_size) & (ICACHE_REFILLS_WORKAROUND_WAR ? ~(cpu_icache_line_size()-1) : ALMASK));
366}
367
368/*
369 * Atomically swap in the new signal mask, and wait for a signal.
370 */
371
372#ifdef CONFIG_TRAD_SIGNALS
373SYSCALL_DEFINE1(sigsuspend, sigset_t __user *, uset)
374{
375 return sys_rt_sigsuspend(uset, sizeof(sigset_t));
376}
377#endif
378
379#ifdef CONFIG_TRAD_SIGNALS
380SYSCALL_DEFINE3(sigaction, int, sig, const struct sigaction __user *, act,
381 struct sigaction __user *, oact)
382{
383 struct k_sigaction new_ka, old_ka;
384 int ret;
385 int err = 0;
386
387 if (act) {
388 old_sigset_t mask;
389
390 if (!access_ok(VERIFY_READ, act, sizeof(*act)))
391 return -EFAULT;
392 err |= __get_user(new_ka.sa.sa_handler, &act->sa_handler);
393 err |= __get_user(new_ka.sa.sa_flags, &act->sa_flags);
394 err |= __get_user(mask, &act->sa_mask.sig[0]);
395 if (err)
396 return -EFAULT;
397
398 siginitset(&new_ka.sa.sa_mask, mask);
399 }
400
401 ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL);
402
403 if (!ret && oact) {
404 if (!access_ok(VERIFY_WRITE, oact, sizeof(*oact)))
405 return -EFAULT;
406 err |= __put_user(old_ka.sa.sa_flags, &oact->sa_flags);
407 err |= __put_user(old_ka.sa.sa_handler, &oact->sa_handler);
408 err |= __put_user(old_ka.sa.sa_mask.sig[0], oact->sa_mask.sig);
409 err |= __put_user(0, &oact->sa_mask.sig[1]);
410 err |= __put_user(0, &oact->sa_mask.sig[2]);
411 err |= __put_user(0, &oact->sa_mask.sig[3]);
412 if (err)
413 return -EFAULT;
414 }
415
416 return ret;
417}
418#endif
419
420#ifdef CONFIG_TRAD_SIGNALS
421asmlinkage void sys_sigreturn(nabi_no_regargs struct pt_regs regs)
422{
423 struct sigframe __user *frame;
424 sigset_t blocked;
425 int sig;
426
427 frame = (struct sigframe __user *) regs.regs[29];
428 if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
429 goto badframe;
430 if (__copy_from_user(&blocked, &frame->sf_mask, sizeof(blocked)))
431 goto badframe;
432
433 set_current_blocked(&blocked);
434
435 sig = restore_sigcontext(®s, &frame->sf_sc);
436 if (sig < 0)
437 goto badframe;
438 else if (sig)
439 force_sig(sig, current);
440
441 /*
442 * Don't let your children do this ...
443 */
444 __asm__ __volatile__(
445 "move\t$29, %0\n\t"
446 "j\tsyscall_exit"
447 :/* no outputs */
448 :"r" (®s));
449 /* Unreached */
450
451badframe:
452 force_sig(SIGSEGV, current);
453}
454#endif /* CONFIG_TRAD_SIGNALS */
455
456asmlinkage void sys_rt_sigreturn(nabi_no_regargs struct pt_regs regs)
457{
458 struct rt_sigframe __user *frame;
459 sigset_t set;
460 int sig;
461
462 frame = (struct rt_sigframe __user *) regs.regs[29];
463 if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
464 goto badframe;
465 if (__copy_from_user(&set, &frame->rs_uc.uc_sigmask, sizeof(set)))
466 goto badframe;
467
468 set_current_blocked(&set);
469
470 sig = restore_sigcontext(®s, &frame->rs_uc.uc_mcontext);
471 if (sig < 0)
472 goto badframe;
473 else if (sig)
474 force_sig(sig, current);
475
476 if (restore_altstack(&frame->rs_uc.uc_stack))
477 goto badframe;
478
479 /*
480 * Don't let your children do this ...
481 */
482 __asm__ __volatile__(
483 "move\t$29, %0\n\t"
484 "j\tsyscall_exit"
485 :/* no outputs */
486 :"r" (®s));
487 /* Unreached */
488
489badframe:
490 force_sig(SIGSEGV, current);
491}
492
493#ifdef CONFIG_TRAD_SIGNALS
494static int setup_frame(void *sig_return, struct k_sigaction *ka,
495 struct pt_regs *regs, int signr, sigset_t *set)
496{
497 struct sigframe __user *frame;
498 int err = 0;
499
500 frame = get_sigframe(ka, regs, sizeof(*frame));
501 if (!access_ok(VERIFY_WRITE, frame, sizeof (*frame)))
502 goto give_sigsegv;
503
504 err |= setup_sigcontext(regs, &frame->sf_sc);
505 err |= __copy_to_user(&frame->sf_mask, set, sizeof(*set));
506 if (err)
507 goto give_sigsegv;
508
509 /*
510 * Arguments to signal handler:
511 *
512 * a0 = signal number
513 * a1 = 0 (should be cause)
514 * a2 = pointer to struct sigcontext
515 *
516 * $25 and c0_epc point to the signal handler, $29 points to the
517 * struct sigframe.
518 */
519 regs->regs[ 4] = signr;
520 regs->regs[ 5] = 0;
521 regs->regs[ 6] = (unsigned long) &frame->sf_sc;
522 regs->regs[29] = (unsigned long) frame;
523 regs->regs[31] = (unsigned long) sig_return;
524 regs->cp0_epc = regs->regs[25] = (unsigned long) ka->sa.sa_handler;
525
526 DEBUGP("SIG deliver (%s:%d): sp=0x%p pc=0x%lx ra=0x%lx\n",
527 current->comm, current->pid,
528 frame, regs->cp0_epc, regs->regs[31]);
529 return 0;
530
531give_sigsegv:
532 force_sigsegv(signr, current);
533 return -EFAULT;
534}
535#endif
536
537static int setup_rt_frame(void *sig_return, struct k_sigaction *ka,
538 struct pt_regs *regs, int signr, sigset_t *set,
539 siginfo_t *info)
540{
541 struct rt_sigframe __user *frame;
542 int err = 0;
543
544 frame = get_sigframe(ka, regs, sizeof(*frame));
545 if (!access_ok(VERIFY_WRITE, frame, sizeof (*frame)))
546 goto give_sigsegv;
547
548 /* Create siginfo. */
549 err |= copy_siginfo_to_user(&frame->rs_info, info);
550
551 /* Create the ucontext. */
552 err |= __put_user(0, &frame->rs_uc.uc_flags);
553 err |= __put_user(NULL, &frame->rs_uc.uc_link);
554 err |= __save_altstack(&frame->rs_uc.uc_stack, regs->regs[29]);
555 err |= setup_sigcontext(regs, &frame->rs_uc.uc_mcontext);
556 err |= __copy_to_user(&frame->rs_uc.uc_sigmask, set, sizeof(*set));
557
558 if (err)
559 goto give_sigsegv;
560
561 /*
562 * Arguments to signal handler:
563 *
564 * a0 = signal number
565 * a1 = 0 (should be cause)
566 * a2 = pointer to ucontext
567 *
568 * $25 and c0_epc point to the signal handler, $29 points to
569 * the struct rt_sigframe.
570 */
571 regs->regs[ 4] = signr;
572 regs->regs[ 5] = (unsigned long) &frame->rs_info;
573 regs->regs[ 6] = (unsigned long) &frame->rs_uc;
574 regs->regs[29] = (unsigned long) frame;
575 regs->regs[31] = (unsigned long) sig_return;
576 regs->cp0_epc = regs->regs[25] = (unsigned long) ka->sa.sa_handler;
577
578 DEBUGP("SIG deliver (%s:%d): sp=0x%p pc=0x%lx ra=0x%lx\n",
579 current->comm, current->pid,
580 frame, regs->cp0_epc, regs->regs[31]);
581
582 return 0;
583
584give_sigsegv:
585 force_sigsegv(signr, current);
586 return -EFAULT;
587}
588
589struct mips_abi mips_abi = {
590#ifdef CONFIG_TRAD_SIGNALS
591 .setup_frame = setup_frame,
592 .signal_return_offset = offsetof(struct mips_vdso, signal_trampoline),
593#endif
594 .setup_rt_frame = setup_rt_frame,
595 .rt_signal_return_offset =
596 offsetof(struct mips_vdso, rt_signal_trampoline),
597 .restart = __NR_restart_syscall
598};
599
600static void handle_signal(unsigned long sig, siginfo_t *info,
601 struct k_sigaction *ka, struct pt_regs *regs)
602{
603 sigset_t *oldset = sigmask_to_save();
604 int ret;
605 struct mips_abi *abi = current->thread.abi;
606#ifdef CONFIG_CPU_MICROMIPS
607 void *vdso;
608 unsigned int tmp = (unsigned int)current->mm->context.vdso;
609
610 set_isa16_mode(tmp);
611 vdso = (void *)tmp;
612#else
613 void *vdso = current->mm->context.vdso;
614#endif
615
616 if (regs->regs[0]) {
617 switch(regs->regs[2]) {
618 case ERESTART_RESTARTBLOCK:
619 case ERESTARTNOHAND:
620 regs->regs[2] = EINTR;
621 break;
622 case ERESTARTSYS:
623 if (!(ka->sa.sa_flags & SA_RESTART)) {
624 regs->regs[2] = EINTR;
625 break;
626 }
627 /* fallthrough */
628 case ERESTARTNOINTR:
629 regs->regs[7] = regs->regs[26];
630 regs->regs[2] = regs->regs[0];
631 regs->cp0_epc -= 4;
632 }
633
634 regs->regs[0] = 0; /* Don't deal with this again. */
635 }
636
637 if (sig_uses_siginfo(ka))
638 ret = abi->setup_rt_frame(vdso + abi->rt_signal_return_offset,
639 ka, regs, sig, oldset, info);
640 else
641 ret = abi->setup_frame(vdso + abi->signal_return_offset,
642 ka, regs, sig, oldset);
643
644 if (ret)
645 return;
646
647 signal_delivered(sig, info, ka, regs, 0);
648}
649
650static void do_signal(struct pt_regs *regs)
651{
652 struct k_sigaction ka;
653 siginfo_t info;
654 int signr;
655
656 signr = get_signal_to_deliver(&info, &ka, regs, NULL);
657 if (signr > 0) {
658 /* Whee! Actually deliver the signal. */
659 handle_signal(signr, &info, &ka, regs);
660 return;
661 }
662
663 if (regs->regs[0]) {
664 switch (regs->regs[2]) {
665 case ERESTARTNOHAND:
666 case ERESTARTSYS:
667 case ERESTARTNOINTR:
668 regs->regs[2] = regs->regs[0];
669 regs->regs[7] = regs->regs[26];
670 regs->cp0_epc -= 4;
671 break;
672
673 case ERESTART_RESTARTBLOCK:
674 regs->regs[2] = current->thread.abi->restart;
675 regs->regs[7] = regs->regs[26];
676 regs->cp0_epc -= 4;
677 break;
678 }
679 regs->regs[0] = 0; /* Don't deal with this again. */
680 }
681
682 /*
683 * If there's no signal to deliver, we just put the saved sigmask
684 * back
685 */
686 restore_saved_sigmask();
687}
688
689/*
690 * notification of userspace execution resumption
691 * - triggered by the TIF_WORK_MASK flags
692 */
693asmlinkage void do_notify_resume(struct pt_regs *regs, void *unused,
694 __u32 thread_info_flags)
695{
696 local_irq_enable();
697
698 user_exit();
699
700 /* deal with pending signal delivery */
701 if (thread_info_flags & _TIF_SIGPENDING)
702 do_signal(regs);
703
704 if (thread_info_flags & _TIF_NOTIFY_RESUME) {
705 clear_thread_flag(TIF_NOTIFY_RESUME);
706 tracehook_notify_resume(regs);
707 }
708
709 user_enter();
710}
711
712#ifdef CONFIG_SMP
713#ifndef CONFIG_EVA
714static int smp_save_fp_context(struct sigcontext __user *sc)
715{
716 return raw_cpu_has_fpu
717 ? _save_fp_context(sc)
718 : copy_fp_to_sigcontext(sc);
719}
720
721static int smp_restore_fp_context(struct sigcontext __user *sc)
722{
723 return raw_cpu_has_fpu
724 ? _restore_fp_context(sc)
725 : copy_fp_from_sigcontext(sc);
726}
727#endif /* CONFIG_EVA */
728#endif
729
730static int signal_setup(void)
731{
732#ifndef CONFIG_EVA
733#ifdef CONFIG_SMP
734 /* For now just do the cpu_has_fpu check when the functions are invoked */
735 save_fp_context = smp_save_fp_context;
736 restore_fp_context = smp_restore_fp_context;
737#else
738 if (cpu_has_fpu) {
739 save_fp_context = _save_fp_context;
740 restore_fp_context = _restore_fp_context;
741 } else {
742 save_fp_context = copy_fp_from_sigcontext;
743 restore_fp_context = copy_fp_to_sigcontext;
744 }
745#endif /* CONFIG_SMP */
746#else
747 save_fp_context = copy_fp_from_sigcontext;;
748 restore_fp_context = copy_fp_to_sigcontext;
749#endif
750
751 return 0;
752}
753
754arch_initcall(signal_setup);