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