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