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