xref: /linux/arch/mips/kernel/signal.c (revision ba6e8564f459211117ce300eae2c7fdd23befe34)
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/sched.h>
12 #include <linux/mm.h>
13 #include <linux/personality.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/compiler.h>
23 
24 #include <asm/abi.h>
25 #include <asm/asm.h>
26 #include <linux/bitops.h>
27 #include <asm/cacheflush.h>
28 #include <asm/fpu.h>
29 #include <asm/sim.h>
30 #include <asm/uaccess.h>
31 #include <asm/ucontext.h>
32 #include <asm/cpu-features.h>
33 #include <asm/war.h>
34 
35 #include "signal-common.h"
36 
37 /*
38  * Horribly complicated - with the bloody RM9000 workarounds enabled
39  * the signal trampolines is moving to the end of the structure so we can
40  * increase the alignment without breaking software compatibility.
41  */
42 #if ICACHE_REFILLS_WORKAROUND_WAR == 0
43 
44 struct sigframe {
45 	u32 sf_ass[4];		/* argument save space for o32 */
46 	u32 sf_code[2];		/* signal trampoline */
47 	struct sigcontext sf_sc;
48 	sigset_t sf_mask;
49 };
50 
51 struct rt_sigframe {
52 	u32 rs_ass[4];		/* argument save space for o32 */
53 	u32 rs_code[2];		/* signal trampoline */
54 	struct siginfo rs_info;
55 	struct ucontext rs_uc;
56 };
57 
58 #else
59 
60 struct sigframe {
61 	u32 sf_ass[4];			/* argument save space for o32 */
62 	u32 sf_pad[2];
63 	struct sigcontext sf_sc;	/* hw context */
64 	sigset_t sf_mask;
65 	u32 sf_code[8] ____cacheline_aligned;	/* signal trampoline */
66 };
67 
68 struct rt_sigframe {
69 	u32 rs_ass[4];			/* argument save space for o32 */
70 	u32 rs_pad[2];
71 	struct siginfo rs_info;
72 	struct ucontext rs_uc;
73 	u32 rs_code[8] ____cacheline_aligned;	/* signal trampoline */
74 };
75 
76 #endif
77 
78 /*
79  * Helper routines
80  */
81 int setup_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc)
82 {
83 	int err = 0;
84 	int i;
85 	unsigned int used_math;
86 
87 	err |= __put_user(regs->cp0_epc, &sc->sc_pc);
88 
89 	err |= __put_user(0, &sc->sc_regs[0]);
90 	for (i = 1; i < 32; i++)
91 		err |= __put_user(regs->regs[i], &sc->sc_regs[i]);
92 
93 #ifdef CONFIG_CPU_HAS_SMARTMIPS
94 	err |= __put_user(regs->acx, &sc->sc_acx);
95 #endif
96 	err |= __put_user(regs->hi, &sc->sc_mdhi);
97 	err |= __put_user(regs->lo, &sc->sc_mdlo);
98 	if (cpu_has_dsp) {
99 		err |= __put_user(mfhi1(), &sc->sc_hi1);
100 		err |= __put_user(mflo1(), &sc->sc_lo1);
101 		err |= __put_user(mfhi2(), &sc->sc_hi2);
102 		err |= __put_user(mflo2(), &sc->sc_lo2);
103 		err |= __put_user(mfhi3(), &sc->sc_hi3);
104 		err |= __put_user(mflo3(), &sc->sc_lo3);
105 		err |= __put_user(rddsp(DSP_MASK), &sc->sc_dsp);
106 	}
107 
108 	used_math = !!used_math();
109 	err |= __put_user(used_math, &sc->sc_used_math);
110 
111 	if (used_math) {
112 		/*
113 		 * Save FPU state to signal context. Signal handler
114 		 * will "inherit" current FPU state.
115 		 */
116 		own_fpu(1);
117 		enable_fp_in_kernel();
118 		err |= save_fp_context(sc);
119 		disable_fp_in_kernel();
120 	}
121 	return err;
122 }
123 
124 int fpcsr_pending(unsigned int __user *fpcsr)
125 {
126 	int err, sig = 0;
127 	unsigned int csr, enabled;
128 
129 	err = __get_user(csr, fpcsr);
130 	enabled = FPU_CSR_UNI_X | ((csr & FPU_CSR_ALL_E) << 5);
131 	/*
132 	 * If the signal handler set some FPU exceptions, clear it and
133 	 * send SIGFPE.
134 	 */
135 	if (csr & enabled) {
136 		csr &= ~enabled;
137 		err |= __put_user(csr, fpcsr);
138 		sig = SIGFPE;
139 	}
140 	return err ?: sig;
141 }
142 
143 static int
144 check_and_restore_fp_context(struct sigcontext __user *sc)
145 {
146 	int err, sig;
147 
148 	err = sig = fpcsr_pending(&sc->sc_fpc_csr);
149 	if (err > 0)
150 		err = 0;
151 	err |= restore_fp_context(sc);
152 	return err ?: sig;
153 }
154 
155 int restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc)
156 {
157 	unsigned int used_math;
158 	unsigned long treg;
159 	int err = 0;
160 	int i;
161 
162 	/* Always make any pending restarted system calls return -EINTR */
163 	current_thread_info()->restart_block.fn = do_no_restart_syscall;
164 
165 	err |= __get_user(regs->cp0_epc, &sc->sc_pc);
166 
167 #ifdef CONFIG_CPU_HAS_SMARTMIPS
168 	err |= __get_user(regs->acx, &sc->sc_acx);
169 #endif
170 	err |= __get_user(regs->hi, &sc->sc_mdhi);
171 	err |= __get_user(regs->lo, &sc->sc_mdlo);
172 	if (cpu_has_dsp) {
173 		err |= __get_user(treg, &sc->sc_hi1); mthi1(treg);
174 		err |= __get_user(treg, &sc->sc_lo1); mtlo1(treg);
175 		err |= __get_user(treg, &sc->sc_hi2); mthi2(treg);
176 		err |= __get_user(treg, &sc->sc_lo2); mtlo2(treg);
177 		err |= __get_user(treg, &sc->sc_hi3); mthi3(treg);
178 		err |= __get_user(treg, &sc->sc_lo3); mtlo3(treg);
179 		err |= __get_user(treg, &sc->sc_dsp); wrdsp(treg, DSP_MASK);
180 	}
181 
182 	for (i = 1; i < 32; i++)
183 		err |= __get_user(regs->regs[i], &sc->sc_regs[i]);
184 
185 	err |= __get_user(used_math, &sc->sc_used_math);
186 	conditional_used_math(used_math);
187 
188 	if (used_math) {
189 		/* restore fpu context if we have used it before */
190 		own_fpu(0);
191 		enable_fp_in_kernel();
192 		if (!err)
193 			err = check_and_restore_fp_context(sc);
194 		disable_fp_in_kernel();
195 	} else {
196 		/* signal handler may have used FPU.  Give it up. */
197 		lose_fpu(0);
198 	}
199 
200 	return err;
201 }
202 
203 void __user *get_sigframe(struct k_sigaction *ka, struct pt_regs *regs,
204 			  size_t frame_size)
205 {
206 	unsigned long sp;
207 
208 	/* Default to using normal stack */
209 	sp = regs->regs[29];
210 
211 	/*
212 	 * FPU emulator may have it's own trampoline active just
213 	 * above the user stack, 16-bytes before the next lowest
214 	 * 16 byte boundary.  Try to avoid trashing it.
215 	 */
216 	sp -= 32;
217 
218 	/* This is the X/Open sanctioned signal stack switching.  */
219 	if ((ka->sa.sa_flags & SA_ONSTACK) && (sas_ss_flags (sp) == 0))
220 		sp = current->sas_ss_sp + current->sas_ss_size;
221 
222 	return (void __user *)((sp - frame_size) & (ICACHE_REFILLS_WORKAROUND_WAR ? ~(cpu_icache_line_size()-1) : ALMASK));
223 }
224 
225 int install_sigtramp(unsigned int __user *tramp, unsigned int syscall)
226 {
227 	int err;
228 
229 	/*
230 	 * Set up the return code ...
231 	 *
232 	 *         li      v0, __NR__foo_sigreturn
233 	 *         syscall
234 	 */
235 
236 	err = __put_user(0x24020000 + syscall, tramp + 0);
237 	err |= __put_user(0x0000000c         , tramp + 1);
238 	if (ICACHE_REFILLS_WORKAROUND_WAR) {
239 		err |= __put_user(0, tramp + 2);
240 		err |= __put_user(0, tramp + 3);
241 		err |= __put_user(0, tramp + 4);
242 		err |= __put_user(0, tramp + 5);
243 		err |= __put_user(0, tramp + 6);
244 		err |= __put_user(0, tramp + 7);
245 	}
246 	flush_cache_sigtramp((unsigned long) tramp);
247 
248 	return err;
249 }
250 
251 /*
252  * Atomically swap in the new signal mask, and wait for a signal.
253  */
254 
255 #ifdef CONFIG_TRAD_SIGNALS
256 asmlinkage int sys_sigsuspend(nabi_no_regargs struct pt_regs regs)
257 {
258 	sigset_t newset;
259 	sigset_t __user *uset;
260 
261 	uset = (sigset_t __user *) regs.regs[4];
262 	if (copy_from_user(&newset, uset, sizeof(sigset_t)))
263 		return -EFAULT;
264 	sigdelsetmask(&newset, ~_BLOCKABLE);
265 
266 	spin_lock_irq(&current->sighand->siglock);
267 	current->saved_sigmask = current->blocked;
268 	current->blocked = newset;
269 	recalc_sigpending();
270 	spin_unlock_irq(&current->sighand->siglock);
271 
272 	current->state = TASK_INTERRUPTIBLE;
273 	schedule();
274 	set_thread_flag(TIF_RESTORE_SIGMASK);
275 	return -ERESTARTNOHAND;
276 }
277 #endif
278 
279 asmlinkage int sys_rt_sigsuspend(nabi_no_regargs struct pt_regs regs)
280 {
281 	sigset_t newset;
282 	sigset_t __user *unewset;
283 	size_t sigsetsize;
284 
285 	/* XXX Don't preclude handling different sized sigset_t's.  */
286 	sigsetsize = regs.regs[5];
287 	if (sigsetsize != sizeof(sigset_t))
288 		return -EINVAL;
289 
290 	unewset = (sigset_t __user *) regs.regs[4];
291 	if (copy_from_user(&newset, unewset, sizeof(newset)))
292 		return -EFAULT;
293 	sigdelsetmask(&newset, ~_BLOCKABLE);
294 
295 	spin_lock_irq(&current->sighand->siglock);
296 	current->saved_sigmask = current->blocked;
297 	current->blocked = newset;
298 	recalc_sigpending();
299 	spin_unlock_irq(&current->sighand->siglock);
300 
301 	current->state = TASK_INTERRUPTIBLE;
302 	schedule();
303 	set_thread_flag(TIF_RESTORE_SIGMASK);
304 	return -ERESTARTNOHAND;
305 }
306 
307 #ifdef CONFIG_TRAD_SIGNALS
308 asmlinkage int sys_sigaction(int sig, const struct sigaction __user *act,
309 	struct sigaction __user *oact)
310 {
311 	struct k_sigaction new_ka, old_ka;
312 	int ret;
313 	int err = 0;
314 
315 	if (act) {
316 		old_sigset_t mask;
317 
318 		if (!access_ok(VERIFY_READ, act, sizeof(*act)))
319 			return -EFAULT;
320 		err |= __get_user(new_ka.sa.sa_handler, &act->sa_handler);
321 		err |= __get_user(new_ka.sa.sa_flags, &act->sa_flags);
322 		err |= __get_user(mask, &act->sa_mask.sig[0]);
323 		if (err)
324 			return -EFAULT;
325 
326 		siginitset(&new_ka.sa.sa_mask, mask);
327 	}
328 
329 	ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL);
330 
331 	if (!ret && oact) {
332 		if (!access_ok(VERIFY_WRITE, oact, sizeof(*oact)))
333 			return -EFAULT;
334 		err |= __put_user(old_ka.sa.sa_flags, &oact->sa_flags);
335 		err |= __put_user(old_ka.sa.sa_handler, &oact->sa_handler);
336 		err |= __put_user(old_ka.sa.sa_mask.sig[0], oact->sa_mask.sig);
337 		err |= __put_user(0, &oact->sa_mask.sig[1]);
338 		err |= __put_user(0, &oact->sa_mask.sig[2]);
339 		err |= __put_user(0, &oact->sa_mask.sig[3]);
340 		if (err)
341 			return -EFAULT;
342 	}
343 
344 	return ret;
345 }
346 #endif
347 
348 asmlinkage int sys_sigaltstack(nabi_no_regargs struct pt_regs regs)
349 {
350 	const stack_t __user *uss = (const stack_t __user *) regs.regs[4];
351 	stack_t __user *uoss = (stack_t __user *) regs.regs[5];
352 	unsigned long usp = regs.regs[29];
353 
354 	return do_sigaltstack(uss, uoss, usp);
355 }
356 
357 #ifdef CONFIG_TRAD_SIGNALS
358 asmlinkage void sys_sigreturn(nabi_no_regargs struct pt_regs regs)
359 {
360 	struct sigframe __user *frame;
361 	sigset_t blocked;
362 	int sig;
363 
364 	frame = (struct sigframe __user *) regs.regs[29];
365 	if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
366 		goto badframe;
367 	if (__copy_from_user(&blocked, &frame->sf_mask, sizeof(blocked)))
368 		goto badframe;
369 
370 	sigdelsetmask(&blocked, ~_BLOCKABLE);
371 	spin_lock_irq(&current->sighand->siglock);
372 	current->blocked = blocked;
373 	recalc_sigpending();
374 	spin_unlock_irq(&current->sighand->siglock);
375 
376 	sig = restore_sigcontext(&regs, &frame->sf_sc);
377 	if (sig < 0)
378 		goto badframe;
379 	else if (sig)
380 		force_sig(sig, current);
381 
382 	/*
383 	 * Don't let your children do this ...
384 	 */
385 	__asm__ __volatile__(
386 		"move\t$29, %0\n\t"
387 		"j\tsyscall_exit"
388 		:/* no outputs */
389 		:"r" (&regs));
390 	/* Unreached */
391 
392 badframe:
393 	force_sig(SIGSEGV, current);
394 }
395 #endif /* CONFIG_TRAD_SIGNALS */
396 
397 asmlinkage void sys_rt_sigreturn(nabi_no_regargs struct pt_regs regs)
398 {
399 	struct rt_sigframe __user *frame;
400 	sigset_t set;
401 	stack_t st;
402 	int sig;
403 
404 	frame = (struct rt_sigframe __user *) regs.regs[29];
405 	if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
406 		goto badframe;
407 	if (__copy_from_user(&set, &frame->rs_uc.uc_sigmask, sizeof(set)))
408 		goto badframe;
409 
410 	sigdelsetmask(&set, ~_BLOCKABLE);
411 	spin_lock_irq(&current->sighand->siglock);
412 	current->blocked = set;
413 	recalc_sigpending();
414 	spin_unlock_irq(&current->sighand->siglock);
415 
416 	sig = restore_sigcontext(&regs, &frame->rs_uc.uc_mcontext);
417 	if (sig < 0)
418 		goto badframe;
419 	else if (sig)
420 		force_sig(sig, current);
421 
422 	if (__copy_from_user(&st, &frame->rs_uc.uc_stack, sizeof(st)))
423 		goto badframe;
424 	/* It is more difficult to avoid calling this function than to
425 	   call it and ignore errors.  */
426 	do_sigaltstack((stack_t __user *)&st, NULL, regs.regs[29]);
427 
428 	/*
429 	 * Don't let your children do this ...
430 	 */
431 	__asm__ __volatile__(
432 		"move\t$29, %0\n\t"
433 		"j\tsyscall_exit"
434 		:/* no outputs */
435 		:"r" (&regs));
436 	/* Unreached */
437 
438 badframe:
439 	force_sig(SIGSEGV, current);
440 }
441 
442 #ifdef CONFIG_TRAD_SIGNALS
443 static int setup_frame(struct k_sigaction * ka, struct pt_regs *regs,
444 	int signr, sigset_t *set)
445 {
446 	struct sigframe __user *frame;
447 	int err = 0;
448 
449 	frame = get_sigframe(ka, regs, sizeof(*frame));
450 	if (!access_ok(VERIFY_WRITE, frame, sizeof (*frame)))
451 		goto give_sigsegv;
452 
453 	err |= install_sigtramp(frame->sf_code, __NR_sigreturn);
454 
455 	err |= setup_sigcontext(regs, &frame->sf_sc);
456 	err |= __copy_to_user(&frame->sf_mask, set, sizeof(*set));
457 	if (err)
458 		goto give_sigsegv;
459 
460 	/*
461 	 * Arguments to signal handler:
462 	 *
463 	 *   a0 = signal number
464 	 *   a1 = 0 (should be cause)
465 	 *   a2 = pointer to struct sigcontext
466 	 *
467 	 * $25 and c0_epc point to the signal handler, $29 points to the
468 	 * struct sigframe.
469 	 */
470 	regs->regs[ 4] = signr;
471 	regs->regs[ 5] = 0;
472 	regs->regs[ 6] = (unsigned long) &frame->sf_sc;
473 	regs->regs[29] = (unsigned long) frame;
474 	regs->regs[31] = (unsigned long) frame->sf_code;
475 	regs->cp0_epc = regs->regs[25] = (unsigned long) ka->sa.sa_handler;
476 
477 	DEBUGP("SIG deliver (%s:%d): sp=0x%p pc=0x%lx ra=0x%lx\n",
478 	       current->comm, current->pid,
479 	       frame, regs->cp0_epc, regs->regs[31]);
480 	return 0;
481 
482 give_sigsegv:
483 	force_sigsegv(signr, current);
484 	return -EFAULT;
485 }
486 #endif
487 
488 static int setup_rt_frame(struct k_sigaction * ka, struct pt_regs *regs,
489 	int signr, sigset_t *set, siginfo_t *info)
490 {
491 	struct rt_sigframe __user *frame;
492 	int err = 0;
493 
494 	frame = get_sigframe(ka, regs, sizeof(*frame));
495 	if (!access_ok(VERIFY_WRITE, frame, sizeof (*frame)))
496 		goto give_sigsegv;
497 
498 	err |= install_sigtramp(frame->rs_code, __NR_rt_sigreturn);
499 
500 	/* Create siginfo.  */
501 	err |= copy_siginfo_to_user(&frame->rs_info, info);
502 
503 	/* Create the ucontext.  */
504 	err |= __put_user(0, &frame->rs_uc.uc_flags);
505 	err |= __put_user(NULL, &frame->rs_uc.uc_link);
506 	err |= __put_user((void __user *)current->sas_ss_sp,
507 	                  &frame->rs_uc.uc_stack.ss_sp);
508 	err |= __put_user(sas_ss_flags(regs->regs[29]),
509 	                  &frame->rs_uc.uc_stack.ss_flags);
510 	err |= __put_user(current->sas_ss_size,
511 	                  &frame->rs_uc.uc_stack.ss_size);
512 	err |= setup_sigcontext(regs, &frame->rs_uc.uc_mcontext);
513 	err |= __copy_to_user(&frame->rs_uc.uc_sigmask, set, sizeof(*set));
514 
515 	if (err)
516 		goto give_sigsegv;
517 
518 	/*
519 	 * Arguments to signal handler:
520 	 *
521 	 *   a0 = signal number
522 	 *   a1 = 0 (should be cause)
523 	 *   a2 = pointer to ucontext
524 	 *
525 	 * $25 and c0_epc point to the signal handler, $29 points to
526 	 * the struct rt_sigframe.
527 	 */
528 	regs->regs[ 4] = signr;
529 	regs->regs[ 5] = (unsigned long) &frame->rs_info;
530 	regs->regs[ 6] = (unsigned long) &frame->rs_uc;
531 	regs->regs[29] = (unsigned long) frame;
532 	regs->regs[31] = (unsigned long) frame->rs_code;
533 	regs->cp0_epc = regs->regs[25] = (unsigned long) ka->sa.sa_handler;
534 
535 	DEBUGP("SIG deliver (%s:%d): sp=0x%p pc=0x%lx ra=0x%lx\n",
536 	       current->comm, current->pid,
537 	       frame, regs->cp0_epc, regs->regs[31]);
538 
539 	return 0;
540 
541 give_sigsegv:
542 	force_sigsegv(signr, current);
543 	return -EFAULT;
544 }
545 
546 struct mips_abi mips_abi = {
547 #ifdef CONFIG_TRAD_SIGNALS
548 	.setup_frame	= setup_frame,
549 #endif
550 	.setup_rt_frame	= setup_rt_frame,
551 	.restart	= __NR_restart_syscall
552 };
553 
554 static int handle_signal(unsigned long sig, siginfo_t *info,
555 	struct k_sigaction *ka, sigset_t *oldset, struct pt_regs *regs)
556 {
557 	int ret;
558 
559 	switch(regs->regs[0]) {
560 	case ERESTART_RESTARTBLOCK:
561 	case ERESTARTNOHAND:
562 		regs->regs[2] = EINTR;
563 		break;
564 	case ERESTARTSYS:
565 		if (!(ka->sa.sa_flags & SA_RESTART)) {
566 			regs->regs[2] = EINTR;
567 			break;
568 		}
569 	/* fallthrough */
570 	case ERESTARTNOINTR:		/* Userland will reload $v0.  */
571 		regs->regs[7] = regs->regs[26];
572 		regs->cp0_epc -= 8;
573 	}
574 
575 	regs->regs[0] = 0;		/* Don't deal with this again.  */
576 
577 	if (sig_uses_siginfo(ka))
578 		ret = current->thread.abi->setup_rt_frame(ka, regs, sig, oldset, info);
579 	else
580 		ret = current->thread.abi->setup_frame(ka, regs, sig, oldset);
581 
582 	spin_lock_irq(&current->sighand->siglock);
583 	sigorsets(&current->blocked,&current->blocked,&ka->sa.sa_mask);
584 	if (!(ka->sa.sa_flags & SA_NODEFER))
585 		sigaddset(&current->blocked,sig);
586 	recalc_sigpending();
587 	spin_unlock_irq(&current->sighand->siglock);
588 
589 	return ret;
590 }
591 
592 static void do_signal(struct pt_regs *regs)
593 {
594 	struct k_sigaction ka;
595 	sigset_t *oldset;
596 	siginfo_t info;
597 	int signr;
598 
599 	/*
600 	 * We want the common case to go fast, which is why we may in certain
601 	 * cases get here from kernel mode. Just return without doing anything
602 	 * if so.
603 	 */
604 	if (!user_mode(regs))
605 		return;
606 
607 	if (test_thread_flag(TIF_RESTORE_SIGMASK))
608 		oldset = &current->saved_sigmask;
609 	else
610 		oldset = &current->blocked;
611 
612 	signr = get_signal_to_deliver(&info, &ka, regs, NULL);
613 	if (signr > 0) {
614 		/* Whee!  Actually deliver the signal.  */
615 		if (handle_signal(signr, &info, &ka, oldset, regs) == 0) {
616 			/*
617 			 * A signal was successfully delivered; the saved
618 			 * sigmask will have been stored in the signal frame,
619 			 * and will be restored by sigreturn, so we can simply
620 			 * clear the TIF_RESTORE_SIGMASK flag.
621 			 */
622 			if (test_thread_flag(TIF_RESTORE_SIGMASK))
623 				clear_thread_flag(TIF_RESTORE_SIGMASK);
624 		}
625 
626 		return;
627 	}
628 
629 	/*
630 	 * Who's code doesn't conform to the restartable syscall convention
631 	 * dies here!!!  The li instruction, a single machine instruction,
632 	 * must directly be followed by the syscall instruction.
633 	 */
634 	if (regs->regs[0]) {
635 		if (regs->regs[2] == ERESTARTNOHAND ||
636 		    regs->regs[2] == ERESTARTSYS ||
637 		    regs->regs[2] == ERESTARTNOINTR) {
638 			regs->regs[7] = regs->regs[26];
639 			regs->cp0_epc -= 8;
640 		}
641 		if (regs->regs[2] == ERESTART_RESTARTBLOCK) {
642 			regs->regs[2] = current->thread.abi->restart;
643 			regs->regs[7] = regs->regs[26];
644 			regs->cp0_epc -= 4;
645 		}
646 		regs->regs[0] = 0;	/* Don't deal with this again.  */
647 	}
648 
649 	/*
650 	 * If there's no signal to deliver, we just put the saved sigmask
651 	 * back
652 	 */
653 	if (test_thread_flag(TIF_RESTORE_SIGMASK)) {
654 		clear_thread_flag(TIF_RESTORE_SIGMASK);
655 		sigprocmask(SIG_SETMASK, &current->saved_sigmask, NULL);
656 	}
657 }
658 
659 /*
660  * notification of userspace execution resumption
661  * - triggered by the TIF_WORK_MASK flags
662  */
663 asmlinkage void do_notify_resume(struct pt_regs *regs, void *unused,
664 	__u32 thread_info_flags)
665 {
666 	/* deal with pending signal delivery */
667 	if (thread_info_flags & (_TIF_SIGPENDING | _TIF_RESTORE_SIGMASK))
668 		do_signal(regs);
669 }
670