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/uprobes.h>
 25#include <linux/compiler.h>
 26#include <linux/syscalls.h>
 27#include <linux/uaccess.h>
 28#include <linux/tracehook.h>
 29
 30#include <asm/abi.h>
 31#include <asm/asm.h>
 32#include <linux/bitops.h>
 33#include <asm/cacheflush.h>
 34#include <asm/fpu.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/dsp.h>
 40#include <asm/inst.h>
 41#include <asm/msa.h>
 42
 43#include "signal-common.h"
 44
 45static int (*save_fp_context)(void __user *sc);
 46static int (*restore_fp_context)(void __user *sc);
 
 
 
 
 
 
 47
 48struct sigframe {
 49	u32 sf_ass[4];		/* argument save space for o32 */
 50	u32 sf_pad[2];		/* Was: signal trampoline */
 51
 52	/* Matches struct ucontext from its uc_mcontext field onwards */
 53	struct sigcontext sf_sc;
 54	sigset_t sf_mask;
 55	unsigned long long sf_extcontext[0];
 56};
 57
 58struct rt_sigframe {
 59	u32 rs_ass[4];		/* argument save space for o32 */
 60	u32 rs_pad[2];		/* Was: signal trampoline */
 61	struct siginfo rs_info;
 62	struct ucontext rs_uc;
 63};
 64
 65#ifdef CONFIG_MIPS_FP_SUPPORT
 66
 67/*
 68 * Thread saved context copy to/from a signal context presumed to be on the
 69 * user stack, and therefore accessed with appropriate macros from uaccess.h.
 70 */
 71static int copy_fp_to_sigcontext(void __user *sc)
 72{
 73	struct mips_abi *abi = current->thread.abi;
 74	uint64_t __user *fpregs = sc + abi->off_sc_fpregs;
 75	uint32_t __user *csr = sc + abi->off_sc_fpc_csr;
 76	int i;
 77	int err = 0;
 78	int inc = test_thread_flag(TIF_32BIT_FPREGS) ? 2 : 1;
 79
 80	for (i = 0; i < NUM_FPU_REGS; i += inc) {
 81		err |=
 82		    __put_user(get_fpr64(&current->thread.fpu.fpr[i], 0),
 83			       &fpregs[i]);
 84	}
 85	err |= __put_user(current->thread.fpu.fcr31, csr);
 86
 87	return err;
 88}
 89
 90static int copy_fp_from_sigcontext(void __user *sc)
 91{
 92	struct mips_abi *abi = current->thread.abi;
 93	uint64_t __user *fpregs = sc + abi->off_sc_fpregs;
 94	uint32_t __user *csr = sc + abi->off_sc_fpc_csr;
 95	int i;
 96	int err = 0;
 97	int inc = test_thread_flag(TIF_32BIT_FPREGS) ? 2 : 1;
 98	u64 fpr_val;
 99
100	for (i = 0; i < NUM_FPU_REGS; i += inc) {
101		err |= __get_user(fpr_val, &fpregs[i]);
102		set_fpr64(&current->thread.fpu.fpr[i], 0, fpr_val);
103	}
104	err |= __get_user(current->thread.fpu.fcr31, csr);
105
106	return err;
107}
108
109#else /* !CONFIG_MIPS_FP_SUPPORT */
110
111static int copy_fp_to_sigcontext(void __user *sc)
112{
113	return 0;
114}
115
116static int copy_fp_from_sigcontext(void __user *sc)
117{
118	return 0;
119}
120
121#endif /* !CONFIG_MIPS_FP_SUPPORT */
122
123/*
124 * Wrappers for the assembly _{save,restore}_fp_context functions.
125 */
126static int save_hw_fp_context(void __user *sc)
127{
128	struct mips_abi *abi = current->thread.abi;
129	uint64_t __user *fpregs = sc + abi->off_sc_fpregs;
130	uint32_t __user *csr = sc + abi->off_sc_fpc_csr;
131
132	return _save_fp_context(fpregs, csr);
133}
134
135static int restore_hw_fp_context(void __user *sc)
136{
137	struct mips_abi *abi = current->thread.abi;
138	uint64_t __user *fpregs = sc + abi->off_sc_fpregs;
139	uint32_t __user *csr = sc + abi->off_sc_fpc_csr;
140
141	return _restore_fp_context(fpregs, csr);
142}
143
144/*
145 * Extended context handling.
146 */
147
148static inline void __user *sc_to_extcontext(void __user *sc)
149{
150	struct ucontext __user *uc;
151
152	/*
153	 * We can just pretend the sigcontext is always embedded in a struct
154	 * ucontext here, because the offset from sigcontext to extended
155	 * context is the same in the struct sigframe case.
156	 */
157	uc = container_of(sc, struct ucontext, uc_mcontext);
158	return &uc->uc_extcontext;
159}
160
161#ifdef CONFIG_CPU_HAS_MSA
162
163static int save_msa_extcontext(void __user *buf)
164{
165	struct msa_extcontext __user *msa = buf;
166	uint64_t val;
167	int i, err;
168
169	if (!thread_msa_context_live())
170		return 0;
171
172	/*
173	 * Ensure that we can't lose the live MSA context between checking
174	 * for it & writing it to memory.
175	 */
176	preempt_disable();
177
178	if (is_msa_enabled()) {
179		/*
180		 * There are no EVA versions of the vector register load/store
181		 * instructions, so MSA context has to be saved to kernel memory
182		 * and then copied to user memory. The save to kernel memory
183		 * should already have been done when handling scalar FP
184		 * context.
185		 */
186		BUG_ON(IS_ENABLED(CONFIG_EVA));
187
188		err = __put_user(read_msa_csr(), &msa->csr);
189		err |= _save_msa_all_upper(&msa->wr);
190
191		preempt_enable();
192	} else {
193		preempt_enable();
194
195		err = __put_user(current->thread.fpu.msacsr, &msa->csr);
196
197		for (i = 0; i < NUM_FPU_REGS; i++) {
198			val = get_fpr64(&current->thread.fpu.fpr[i], 1);
199			err |= __put_user(val, &msa->wr[i]);
200		}
201	}
202
203	err |= __put_user(MSA_EXTCONTEXT_MAGIC, &msa->ext.magic);
204	err |= __put_user(sizeof(*msa), &msa->ext.size);
205
206	return err ? -EFAULT : sizeof(*msa);
207}
208
209static int restore_msa_extcontext(void __user *buf, unsigned int size)
210{
211	struct msa_extcontext __user *msa = buf;
212	unsigned long long val;
213	unsigned int csr;
214	int i, err;
215
216	if (size != sizeof(*msa))
217		return -EINVAL;
218
219	err = get_user(csr, &msa->csr);
220	if (err)
221		return err;
222
223	preempt_disable();
224
225	if (is_msa_enabled()) {
226		/*
227		 * There are no EVA versions of the vector register load/store
228		 * instructions, so MSA context has to be copied to kernel
229		 * memory and later loaded to registers. The same is true of
230		 * scalar FP context, so FPU & MSA should have already been
231		 * disabled whilst handling scalar FP context.
232		 */
233		BUG_ON(IS_ENABLED(CONFIG_EVA));
234
235		write_msa_csr(csr);
236		err |= _restore_msa_all_upper(&msa->wr);
237		preempt_enable();
238	} else {
239		preempt_enable();
240
241		current->thread.fpu.msacsr = csr;
242
243		for (i = 0; i < NUM_FPU_REGS; i++) {
244			err |= __get_user(val, &msa->wr[i]);
245			set_fpr64(&current->thread.fpu.fpr[i], 1, val);
246		}
247	}
248
249	return err;
250}
251
252#else /* !CONFIG_CPU_HAS_MSA */
253
254static int save_msa_extcontext(void __user *buf)
255{
256	return 0;
257}
258
259static int restore_msa_extcontext(void __user *buf, unsigned int size)
260{
261	return SIGSYS;
262}
263
264#endif /* !CONFIG_CPU_HAS_MSA */
265
266static int save_extcontext(void __user *buf)
267{
268	int sz;
269
270	sz = save_msa_extcontext(buf);
271	if (sz < 0)
272		return sz;
273	buf += sz;
274
275	/* If no context was saved then trivially return */
276	if (!sz)
277		return 0;
278
279	/* Write the end marker */
280	if (__put_user(END_EXTCONTEXT_MAGIC, (u32 *)buf))
281		return -EFAULT;
282
283	sz += sizeof(((struct extcontext *)NULL)->magic);
284	return sz;
285}
286
287static int restore_extcontext(void __user *buf)
288{
289	struct extcontext ext;
290	int err;
291
292	while (1) {
293		err = __get_user(ext.magic, (unsigned int *)buf);
294		if (err)
295			return err;
296
297		if (ext.magic == END_EXTCONTEXT_MAGIC)
298			return 0;
299
300		err = __get_user(ext.size, (unsigned int *)(buf
301			+ offsetof(struct extcontext, size)));
302		if (err)
303			return err;
304
305		switch (ext.magic) {
306		case MSA_EXTCONTEXT_MAGIC:
307			err = restore_msa_extcontext(buf, ext.size);
308			break;
309
310		default:
311			err = -EINVAL;
312			break;
313		}
314
315		if (err)
316			return err;
317
318		buf += ext.size;
319	}
320}
321
322/*
323 * Helper routines
324 */
325int protected_save_fp_context(void __user *sc)
326{
327	struct mips_abi *abi = current->thread.abi;
328	uint64_t __user *fpregs = sc + abi->off_sc_fpregs;
329	uint32_t __user *csr = sc + abi->off_sc_fpc_csr;
330	uint32_t __user *used_math = sc + abi->off_sc_used_math;
331	unsigned int used, ext_sz;
332	int err;
333
334	used = used_math() ? USED_FP : 0;
335	if (!used)
336		goto fp_done;
337
338	if (!test_thread_flag(TIF_32BIT_FPREGS))
339		used |= USED_FR1;
340	if (test_thread_flag(TIF_HYBRID_FPREGS))
341		used |= USED_HYBRID_FPRS;
342
343	/*
344	 * EVA does not have userland equivalents of ldc1 or sdc1, so
345	 * save to the kernel FP context & copy that to userland below.
346	 */
347	if (IS_ENABLED(CONFIG_EVA))
348		lose_fpu(1);
349
350	while (1) {
351		lock_fpu_owner();
352		if (is_fpu_owner()) {
353			err = save_fp_context(sc);
354			unlock_fpu_owner();
355		} else {
356			unlock_fpu_owner();
357			err = copy_fp_to_sigcontext(sc);
358		}
359		if (likely(!err))
360			break;
361		/* touch the sigcontext and try again */
362		err = __put_user(0, &fpregs[0]) |
363			__put_user(0, &fpregs[31]) |
364			__put_user(0, csr);
365		if (err)
366			return err;	/* really bad sigcontext */
367	}
368
369fp_done:
370	ext_sz = err = save_extcontext(sc_to_extcontext(sc));
371	if (err < 0)
372		return err;
373	used |= ext_sz ? USED_EXTCONTEXT : 0;
374
375	return __put_user(used, used_math);
376}
377
378int protected_restore_fp_context(void __user *sc)
379{
380	struct mips_abi *abi = current->thread.abi;
381	uint64_t __user *fpregs = sc + abi->off_sc_fpregs;
382	uint32_t __user *csr = sc + abi->off_sc_fpc_csr;
383	uint32_t __user *used_math = sc + abi->off_sc_used_math;
384	unsigned int used;
385	int err, sig = 0, tmp __maybe_unused;
386
387	err = __get_user(used, used_math);
388	conditional_used_math(used & USED_FP);
389
390	/*
391	 * The signal handler may have used FPU; give it up if the program
392	 * doesn't want it following sigreturn.
393	 */
394	if (err || !(used & USED_FP))
395		lose_fpu(0);
396	if (err)
397		return err;
398	if (!(used & USED_FP))
399		goto fp_done;
400
401	err = sig = fpcsr_pending(csr);
402	if (err < 0)
403		return err;
404
405	/*
406	 * EVA does not have userland equivalents of ldc1 or sdc1, so we
407	 * disable the FPU here such that the code below simply copies to
408	 * the kernel FP context.
409	 */
410	if (IS_ENABLED(CONFIG_EVA))
411		lose_fpu(0);
412
413	while (1) {
414		lock_fpu_owner();
415		if (is_fpu_owner()) {
416			err = restore_fp_context(sc);
417			unlock_fpu_owner();
418		} else {
419			unlock_fpu_owner();
420			err = copy_fp_from_sigcontext(sc);
421		}
422		if (likely(!err))
423			break;
424		/* touch the sigcontext and try again */
425		err = __get_user(tmp, &fpregs[0]) |
426			__get_user(tmp, &fpregs[31]) |
427			__get_user(tmp, csr);
428		if (err)
429			break;	/* really bad sigcontext */
430	}
431
432fp_done:
433	if (!err && (used & USED_EXTCONTEXT))
434		err = restore_extcontext(sc_to_extcontext(sc));
435
436	return err ?: sig;
437}
438
439int setup_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc)
440{
441	int err = 0;
442	int i;
 
443
444	err |= __put_user(regs->cp0_epc, &sc->sc_pc);
445
446	err |= __put_user(0, &sc->sc_regs[0]);
447	for (i = 1; i < 32; i++)
448		err |= __put_user(regs->regs[i], &sc->sc_regs[i]);
449
450#ifdef CONFIG_CPU_HAS_SMARTMIPS
451	err |= __put_user(regs->acx, &sc->sc_acx);
452#endif
453	err |= __put_user(regs->hi, &sc->sc_mdhi);
454	err |= __put_user(regs->lo, &sc->sc_mdlo);
455	if (cpu_has_dsp) {
456		err |= __put_user(mfhi1(), &sc->sc_hi1);
457		err |= __put_user(mflo1(), &sc->sc_lo1);
458		err |= __put_user(mfhi2(), &sc->sc_hi2);
459		err |= __put_user(mflo2(), &sc->sc_lo2);
460		err |= __put_user(mfhi3(), &sc->sc_hi3);
461		err |= __put_user(mflo3(), &sc->sc_lo3);
462		err |= __put_user(rddsp(DSP_MASK), &sc->sc_dsp);
463	}
464
 
 
465
466	/*
467	 * Save FPU state to signal context. Signal handler
468	 * will "inherit" current FPU state.
469	 */
470	err |= protected_save_fp_context(sc);
471
 
472	return err;
473}
474
475static size_t extcontext_max_size(void)
476{
477	size_t sz = 0;
478
479	/*
480	 * The assumption here is that between this point & the point at which
481	 * the extended context is saved the size of the context should only
482	 * ever be able to shrink (if the task is preempted), but never grow.
483	 * That is, what this function returns is an upper bound on the size of
484	 * the extended context for the current task at the current time.
485	 */
486
487	if (thread_msa_context_live())
488		sz += sizeof(struct msa_extcontext);
489
490	/* If any context is saved then we'll append the end marker */
491	if (sz)
492		sz += sizeof(((struct extcontext *)NULL)->magic);
493
494	return sz;
495}
496
497int fpcsr_pending(unsigned int __user *fpcsr)
498{
499	int err, sig = 0;
500	unsigned int csr, enabled;
501
502	err = __get_user(csr, fpcsr);
503	enabled = FPU_CSR_UNI_X | ((csr & FPU_CSR_ALL_E) << 5);
504	/*
505	 * If the signal handler set some FPU exceptions, clear it and
506	 * send SIGFPE.
507	 */
508	if (csr & enabled) {
509		csr &= ~enabled;
510		err |= __put_user(csr, fpcsr);
511		sig = SIGFPE;
512	}
513	return err ?: sig;
514}
515
 
 
 
 
 
 
 
 
 
 
 
 
516int restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc)
517{
 
518	unsigned long treg;
519	int err = 0;
520	int i;
521
522	/* Always make any pending restarted system calls return -EINTR */
523	current->restart_block.fn = do_no_restart_syscall;
524
525	err |= __get_user(regs->cp0_epc, &sc->sc_pc);
526
527#ifdef CONFIG_CPU_HAS_SMARTMIPS
528	err |= __get_user(regs->acx, &sc->sc_acx);
529#endif
530	err |= __get_user(regs->hi, &sc->sc_mdhi);
531	err |= __get_user(regs->lo, &sc->sc_mdlo);
532	if (cpu_has_dsp) {
533		err |= __get_user(treg, &sc->sc_hi1); mthi1(treg);
534		err |= __get_user(treg, &sc->sc_lo1); mtlo1(treg);
535		err |= __get_user(treg, &sc->sc_hi2); mthi2(treg);
536		err |= __get_user(treg, &sc->sc_lo2); mtlo2(treg);
537		err |= __get_user(treg, &sc->sc_hi3); mthi3(treg);
538		err |= __get_user(treg, &sc->sc_lo3); mtlo3(treg);
539		err |= __get_user(treg, &sc->sc_dsp); wrdsp(treg, DSP_MASK);
540	}
541
542	for (i = 1; i < 32; i++)
543		err |= __get_user(regs->regs[i], &sc->sc_regs[i]);
544
545	return err ?: protected_restore_fp_context(sc);
 
 
 
 
 
 
 
 
 
 
 
 
546}
547
548void __user *get_sigframe(struct ksignal *ksig, struct pt_regs *regs,
549			  size_t frame_size)
550{
551	unsigned long sp;
552
553	/* Leave space for potential extended context */
554	frame_size += extcontext_max_size();
555
556	/* Default to using normal stack */
557	sp = regs->regs[29];
558
559	/*
560	 * FPU emulator may have it's own trampoline active just
561	 * above the user stack, 16-bytes before the next lowest
562	 * 16 byte boundary.  Try to avoid trashing it.
563	 */
564	sp -= 32;
565
566	sp = sigsp(sp, ksig);
 
 
567
568	return (void __user *)((sp - frame_size) & (ICACHE_REFILLS_WORKAROUND_WAR ? ~(cpu_icache_line_size()-1) : ALMASK));
569}
570
571/*
572 * Atomically swap in the new signal mask, and wait for a signal.
573 */
574
575#ifdef CONFIG_TRAD_SIGNALS
576SYSCALL_DEFINE1(sigsuspend, sigset_t __user *, uset)
577{
578	return sys_rt_sigsuspend(uset, sizeof(sigset_t));
 
 
 
 
 
 
579}
580#endif
581
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
582#ifdef CONFIG_TRAD_SIGNALS
583SYSCALL_DEFINE3(sigaction, int, sig, const struct sigaction __user *, act,
584	struct sigaction __user *, oact)
585{
586	struct k_sigaction new_ka, old_ka;
587	int ret;
588	int err = 0;
589
590	if (act) {
591		old_sigset_t mask;
592
593		if (!access_ok(act, sizeof(*act)))
594			return -EFAULT;
595		err |= __get_user(new_ka.sa.sa_handler, &act->sa_handler);
596		err |= __get_user(new_ka.sa.sa_flags, &act->sa_flags);
597		err |= __get_user(mask, &act->sa_mask.sig[0]);
598		if (err)
599			return -EFAULT;
600
601		siginitset(&new_ka.sa.sa_mask, mask);
602	}
603
604	ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL);
605
606	if (!ret && oact) {
607		if (!access_ok(oact, sizeof(*oact)))
608			return -EFAULT;
609		err |= __put_user(old_ka.sa.sa_flags, &oact->sa_flags);
610		err |= __put_user(old_ka.sa.sa_handler, &oact->sa_handler);
611		err |= __put_user(old_ka.sa.sa_mask.sig[0], oact->sa_mask.sig);
612		err |= __put_user(0, &oact->sa_mask.sig[1]);
613		err |= __put_user(0, &oact->sa_mask.sig[2]);
614		err |= __put_user(0, &oact->sa_mask.sig[3]);
615		if (err)
616			return -EFAULT;
617	}
618
619	return ret;
620}
621#endif
622
 
 
 
 
 
 
 
 
 
623#ifdef CONFIG_TRAD_SIGNALS
624asmlinkage void sys_sigreturn(void)
625{
626	struct sigframe __user *frame;
627	struct pt_regs *regs;
628	sigset_t blocked;
629	int sig;
630
631	regs = current_pt_regs();
632	frame = (struct sigframe __user *)regs->regs[29];
633	if (!access_ok(frame, sizeof(*frame)))
634		goto badframe;
635	if (__copy_from_user(&blocked, &frame->sf_mask, sizeof(blocked)))
636		goto badframe;
637
638	set_current_blocked(&blocked);
639
640	sig = restore_sigcontext(regs, &frame->sf_sc);
641	if (sig < 0)
642		goto badframe;
643	else if (sig)
644		force_sig(sig);
645
646	/*
647	 * Don't let your children do this ...
648	 */
649	__asm__ __volatile__(
650		"move\t$29, %0\n\t"
651		"j\tsyscall_exit"
652		: /* no outputs */
653		: "r" (regs));
654	/* Unreached */
655
656badframe:
657	force_sig(SIGSEGV);
658}
659#endif /* CONFIG_TRAD_SIGNALS */
660
661asmlinkage void sys_rt_sigreturn(void)
662{
663	struct rt_sigframe __user *frame;
664	struct pt_regs *regs;
665	sigset_t set;
666	int sig;
667
668	regs = current_pt_regs();
669	frame = (struct rt_sigframe __user *)regs->regs[29];
670	if (!access_ok(frame, sizeof(*frame)))
671		goto badframe;
672	if (__copy_from_user(&set, &frame->rs_uc.uc_sigmask, sizeof(set)))
673		goto badframe;
674
675	set_current_blocked(&set);
676
677	sig = restore_sigcontext(regs, &frame->rs_uc.uc_mcontext);
678	if (sig < 0)
679		goto badframe;
680	else if (sig)
681		force_sig(sig);
682
683	if (restore_altstack(&frame->rs_uc.uc_stack))
684		goto badframe;
 
685
686	/*
687	 * Don't let your children do this ...
688	 */
689	__asm__ __volatile__(
690		"move\t$29, %0\n\t"
691		"j\tsyscall_exit"
692		: /* no outputs */
693		: "r" (regs));
694	/* Unreached */
695
696badframe:
697	force_sig(SIGSEGV);
698}
699
700#ifdef CONFIG_TRAD_SIGNALS
701static int setup_frame(void *sig_return, struct ksignal *ksig,
702		       struct pt_regs *regs, sigset_t *set)
703{
704	struct sigframe __user *frame;
705	int err = 0;
706
707	frame = get_sigframe(ksig, regs, sizeof(*frame));
708	if (!access_ok(frame, sizeof (*frame)))
709		return -EFAULT;
710
711	err |= setup_sigcontext(regs, &frame->sf_sc);
712	err |= __copy_to_user(&frame->sf_mask, set, sizeof(*set));
713	if (err)
714		return -EFAULT;
715
716	/*
717	 * Arguments to signal handler:
718	 *
719	 *   a0 = signal number
720	 *   a1 = 0 (should be cause)
721	 *   a2 = pointer to struct sigcontext
722	 *
723	 * $25 and c0_epc point to the signal handler, $29 points to the
724	 * struct sigframe.
725	 */
726	regs->regs[ 4] = ksig->sig;
727	regs->regs[ 5] = 0;
728	regs->regs[ 6] = (unsigned long) &frame->sf_sc;
729	regs->regs[29] = (unsigned long) frame;
730	regs->regs[31] = (unsigned long) sig_return;
731	regs->cp0_epc = regs->regs[25] = (unsigned long) ksig->ka.sa.sa_handler;
732
733	DEBUGP("SIG deliver (%s:%d): sp=0x%p pc=0x%lx ra=0x%lx\n",
734	       current->comm, current->pid,
735	       frame, regs->cp0_epc, regs->regs[31]);
736	return 0;
 
 
 
 
737}
738#endif
739
740static int setup_rt_frame(void *sig_return, struct ksignal *ksig,
741			  struct pt_regs *regs, sigset_t *set)
 
742{
743	struct rt_sigframe __user *frame;
744	int err = 0;
745
746	frame = get_sigframe(ksig, regs, sizeof(*frame));
747	if (!access_ok(frame, sizeof (*frame)))
748		return -EFAULT;
749
750	/* Create siginfo.  */
751	err |= copy_siginfo_to_user(&frame->rs_info, &ksig->info);
752
753	/* Create the ucontext.	 */
754	err |= __put_user(0, &frame->rs_uc.uc_flags);
755	err |= __put_user(NULL, &frame->rs_uc.uc_link);
756	err |= __save_altstack(&frame->rs_uc.uc_stack, regs->regs[29]);
 
 
 
 
 
757	err |= setup_sigcontext(regs, &frame->rs_uc.uc_mcontext);
758	err |= __copy_to_user(&frame->rs_uc.uc_sigmask, set, sizeof(*set));
759
760	if (err)
761		return -EFAULT;
762
763	/*
764	 * Arguments to signal handler:
765	 *
766	 *   a0 = signal number
767	 *   a1 = 0 (should be cause)
768	 *   a2 = pointer to ucontext
769	 *
770	 * $25 and c0_epc point to the signal handler, $29 points to
771	 * the struct rt_sigframe.
772	 */
773	regs->regs[ 4] = ksig->sig;
774	regs->regs[ 5] = (unsigned long) &frame->rs_info;
775	regs->regs[ 6] = (unsigned long) &frame->rs_uc;
776	regs->regs[29] = (unsigned long) frame;
777	regs->regs[31] = (unsigned long) sig_return;
778	regs->cp0_epc = regs->regs[25] = (unsigned long) ksig->ka.sa.sa_handler;
779
780	DEBUGP("SIG deliver (%s:%d): sp=0x%p pc=0x%lx ra=0x%lx\n",
781	       current->comm, current->pid,
782	       frame, regs->cp0_epc, regs->regs[31]);
783
784	return 0;
 
 
 
 
785}
786
787struct mips_abi mips_abi = {
788#ifdef CONFIG_TRAD_SIGNALS
789	.setup_frame	= setup_frame,
 
790#endif
791	.setup_rt_frame = setup_rt_frame,
792	.restart	= __NR_restart_syscall,
793
794	.off_sc_fpregs = offsetof(struct sigcontext, sc_fpregs),
795	.off_sc_fpc_csr = offsetof(struct sigcontext, sc_fpc_csr),
796	.off_sc_used_math = offsetof(struct sigcontext, sc_used_math),
797
798	.vdso		= &vdso_image,
799};
800
801static void handle_signal(struct ksignal *ksig, struct pt_regs *regs)
 
802{
803	sigset_t *oldset = sigmask_to_save();
804	int ret;
805	struct mips_abi *abi = current->thread.abi;
806	void *vdso = current->mm->context.vdso;
807
808	/*
809	 * If we were emulating a delay slot instruction, exit that frame such
810	 * that addresses in the sigframe are as expected for userland and we
811	 * don't have a problem if we reuse the thread's frame for an
812	 * instruction within the signal handler.
813	 */
814	dsemul_thread_rollback(regs);
815
816	if (regs->regs[0]) {
817		switch(regs->regs[2]) {
818		case ERESTART_RESTARTBLOCK:
819		case ERESTARTNOHAND:
820			regs->regs[2] = EINTR;
821			break;
822		case ERESTARTSYS:
823			if (!(ksig->ka.sa.sa_flags & SA_RESTART)) {
824				regs->regs[2] = EINTR;
825				break;
826			}
827		/* fallthrough */
828		case ERESTARTNOINTR:
829			regs->regs[7] = regs->regs[26];
830			regs->regs[2] = regs->regs[0];
831			regs->cp0_epc -= 4;
832		}
833
834		regs->regs[0] = 0;		/* Don't deal with this again.	*/
835	}
836
837	rseq_signal_deliver(ksig, regs);
838
839	if (sig_uses_siginfo(&ksig->ka, abi))
840		ret = abi->setup_rt_frame(vdso + abi->vdso->off_rt_sigreturn,
841					  ksig, regs, oldset);
842	else
843		ret = abi->setup_frame(vdso + abi->vdso->off_sigreturn,
844				       ksig, regs, oldset);
845
846	signal_setup_done(ret, ksig, 0);
 
 
 
847}
848
849static void do_signal(struct pt_regs *regs)
850{
851	struct ksignal ksig;
 
 
852
853	if (get_signal(&ksig)) {
854		/* Whee!  Actually deliver the signal.	*/
855		handle_signal(&ksig, regs);
 
 
 
 
 
 
 
 
 
856		return;
857	}
858
859	if (regs->regs[0]) {
860		switch (regs->regs[2]) {
861		case ERESTARTNOHAND:
862		case ERESTARTSYS:
863		case ERESTARTNOINTR:
864			regs->regs[2] = regs->regs[0];
865			regs->regs[7] = regs->regs[26];
866			regs->cp0_epc -= 4;
867			break;
868
869		case ERESTART_RESTARTBLOCK:
870			regs->regs[2] = current->thread.abi->restart;
871			regs->regs[7] = regs->regs[26];
872			regs->cp0_epc -= 4;
873			break;
874		}
875		regs->regs[0] = 0;	/* Don't deal with this again.	*/
876	}
877
878	/*
879	 * If there's no signal to deliver, we just put the saved sigmask
880	 * back
881	 */
882	restore_saved_sigmask();
883}
884
885/*
886 * notification of userspace execution resumption
887 * - triggered by the TIF_WORK_MASK flags
888 */
889asmlinkage void do_notify_resume(struct pt_regs *regs, void *unused,
890	__u32 thread_info_flags)
891{
892	local_irq_enable();
893
894	user_exit();
895
896	if (thread_info_flags & _TIF_UPROBE)
897		uprobe_notify_resume(regs);
898
899	/* deal with pending signal delivery */
900	if (thread_info_flags & _TIF_SIGPENDING)
901		do_signal(regs);
902
903	if (thread_info_flags & _TIF_NOTIFY_RESUME) {
904		clear_thread_flag(TIF_NOTIFY_RESUME);
905		tracehook_notify_resume(regs);
906		rseq_handle_notify_resume(NULL, regs);
907	}
908
909	user_enter();
910}
911
912#if defined(CONFIG_SMP) && defined(CONFIG_MIPS_FP_SUPPORT)
913static int smp_save_fp_context(void __user *sc)
914{
915	return raw_cpu_has_fpu
916	       ? save_hw_fp_context(sc)
917	       : copy_fp_to_sigcontext(sc);
918}
919
920static int smp_restore_fp_context(void __user *sc)
921{
922	return raw_cpu_has_fpu
923	       ? restore_hw_fp_context(sc)
924	       : copy_fp_from_sigcontext(sc);
925}
926#endif
927
928static int signal_setup(void)
929{
930	/*
931	 * The offset from sigcontext to extended context should be the same
932	 * regardless of the type of signal, such that userland can always know
933	 * where to look if it wishes to find the extended context structures.
934	 */
935	BUILD_BUG_ON((offsetof(struct sigframe, sf_extcontext) -
936		      offsetof(struct sigframe, sf_sc)) !=
937		     (offsetof(struct rt_sigframe, rs_uc.uc_extcontext) -
938		      offsetof(struct rt_sigframe, rs_uc.uc_mcontext)));
939
940#if defined(CONFIG_SMP) && defined(CONFIG_MIPS_FP_SUPPORT)
941	/* For now just do the cpu_has_fpu check when the functions are invoked */
942	save_fp_context = smp_save_fp_context;
943	restore_fp_context = smp_restore_fp_context;
944#else
945	if (cpu_has_fpu) {
946		save_fp_context = save_hw_fp_context;
947		restore_fp_context = restore_hw_fp_context;
948	} else {
949		save_fp_context = copy_fp_to_sigcontext;
950		restore_fp_context = copy_fp_from_sigcontext;
951	}
952#endif /* CONFIG_SMP */
953
954	return 0;
955}
956
957arch_initcall(signal_setup);