xref: /openbmc/linux/arch/mips/kernel/signal.c (revision b34e08d5)
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 
45 static int (*save_fp_context)(struct sigcontext __user *sc);
46 static int (*restore_fp_context)(struct sigcontext __user *sc);
47 
48 extern asmlinkage int _save_fp_context(struct sigcontext __user *sc);
49 extern asmlinkage int _restore_fp_context(struct sigcontext __user *sc);
50 
51 extern asmlinkage int _save_msa_context(struct sigcontext __user *sc);
52 extern asmlinkage int _restore_msa_context(struct sigcontext __user *sc);
53 
54 struct 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 
61 struct 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  */
72 static 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(&current->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 
87 static 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(&current->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  */
106 static 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(&current->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 
121 static 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(&current->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  */
139 static 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 
181 static 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 
228 int 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 
269 int 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 
288 static int
289 check_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 
300 int 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 
346 void __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
373 SYSCALL_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
380 SYSCALL_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
421 asmlinkage 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(&regs, &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" (&regs));
449 	/* Unreached */
450 
451 badframe:
452 	force_sig(SIGSEGV, current);
453 }
454 #endif /* CONFIG_TRAD_SIGNALS */
455 
456 asmlinkage 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(&regs, &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" (&regs));
487 	/* Unreached */
488 
489 badframe:
490 	force_sig(SIGSEGV, current);
491 }
492 
493 #ifdef CONFIG_TRAD_SIGNALS
494 static 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 
531 give_sigsegv:
532 	force_sigsegv(signr, current);
533 	return -EFAULT;
534 }
535 #endif
536 
537 static 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 
584 give_sigsegv:
585 	force_sigsegv(signr, current);
586 	return -EFAULT;
587 }
588 
589 struct 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 
600 static 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 
650 static 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  */
693 asmlinkage 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
714 static 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 
721 static 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 
730 static 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 
754 arch_initcall(signal_setup);
755