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
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.
11 #include <linux/cache.h>
12 #include <linux/context_tracking.h>
13 #include <linux/irqflags.h>
14 #include <linux/sched.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>
31 #include <linux/bitops.h>
32 #include <asm/cacheflush.h>
36 #include <asm/ucontext.h>
37 #include <asm/cpu-features.h>
43 #include "signal-common.h"
45 static int (*save_fp_context)(struct sigcontext __user *sc);
46 static int (*restore_fp_context)(struct sigcontext __user *sc);
48 extern asmlinkage int _save_fp_context(struct sigcontext __user *sc);
49 extern asmlinkage int _restore_fp_context(struct sigcontext __user *sc);
51 extern asmlinkage int _save_msa_context(struct sigcontext __user *sc);
52 extern asmlinkage int _restore_msa_context(struct sigcontext __user *sc);
55 u32 sf_ass[4]; /* argument save space for o32 */
56 u32 sf_pad[2]; /* Was: signal trampoline */
57 struct sigcontext sf_sc;
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;
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.
72 static int copy_fp_to_sigcontext(struct sigcontext __user *sc)
77 for (i = 0; i < NUM_FPU_REGS; i++) {
79 __put_user(get_fpr64(¤t->thread.fpu.fpr[i], 0),
82 err |= __put_user(current->thread.fpu.fcr31, &sc->sc_fpc_csr);
87 static int copy_fp_from_sigcontext(struct sigcontext __user *sc)
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);
97 err |= __get_user(current->thread.fpu.fcr31, &sc->sc_fpc_csr);
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.
106 static int copy_msa_to_sigcontext(struct sigcontext __user *sc)
111 for (i = 0; i < NUM_FPU_REGS; i++) {
113 __put_user(get_fpr64(¤t->thread.fpu.fpr[i], 1),
116 err |= __put_user(current->thread.fpu.msacsr, &sc->sc_msa_csr);
121 static int copy_msa_from_sigcontext(struct sigcontext __user *sc)
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);
131 err |= __get_user(current->thread.fpu.msacsr, &sc->sc_msa_csr);
139 static int protected_save_fp_context(struct sigcontext __user *sc,
143 bool save_msa = cpu_has_msa && (used_math & USEDMATH_MSA);
147 if (is_fpu_owner()) {
148 err = save_fp_context(sc);
149 if (save_msa && !err)
150 err = _save_msa_context(sc);
154 err = copy_fp_to_sigcontext(sc);
155 if (save_msa && !err)
156 err = copy_msa_to_sigcontext(sc);
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);
165 break; /* really bad sigcontext */
169 * EVA does not have FPU EVA instructions so saving fpu context directly
174 err = save_fp_context(sc); /* this might fail */
175 if (save_msa && !err)
176 err = copy_msa_to_sigcontext(sc);
181 static int protected_restore_fp_context(struct sigcontext __user *sc,
184 int err, tmp __maybe_unused;
185 bool restore_msa = cpu_has_msa && (used_math & USEDMATH_MSA);
189 if (is_fpu_owner()) {
190 err = restore_fp_context(sc);
191 if (restore_msa && !err) {
193 err = _restore_msa_context(sc);
195 /* signal handler may have used MSA */
201 err = copy_fp_from_sigcontext(sc);
202 if (!err && (used_math & USEDMATH_MSA))
203 err = copy_msa_from_sigcontext(sc);
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);
212 break; /* really bad sigcontext */
216 * EVA does not have FPU EVA instructions so restoring fpu context
217 * directly does not work.
221 err = restore_fp_context(sc); /* this might fail */
222 if (restore_msa && !err)
223 err = copy_msa_from_sigcontext(sc);
228 int setup_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc)
232 unsigned int used_math;
234 err |= __put_user(regs->cp0_epc, &sc->sc_pc);
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]);
240 #ifdef CONFIG_CPU_HAS_SMARTMIPS
241 err |= __put_user(regs->acx, &sc->sc_acx);
243 err |= __put_user(regs->hi, &sc->sc_mdhi);
244 err |= __put_user(regs->lo, &sc->sc_mdlo);
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);
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);
261 * Save FPU state to signal context. Signal handler
262 * will "inherit" current FPU state.
264 err |= protected_save_fp_context(sc, used_math);
269 int fpcsr_pending(unsigned int __user *fpcsr)
272 unsigned int csr, enabled;
274 err = __get_user(csr, fpcsr);
275 enabled = FPU_CSR_UNI_X | ((csr & FPU_CSR_ALL_E) << 5);
277 * If the signal handler set some FPU exceptions, clear it and
282 err |= __put_user(csr, fpcsr);
289 check_and_restore_fp_context(struct sigcontext __user *sc, unsigned used_math)
293 err = sig = fpcsr_pending(&sc->sc_fpc_csr);
296 err |= protected_restore_fp_context(sc, used_math);
300 int restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc)
302 unsigned int used_math;
307 /* Always make any pending restarted system calls return -EINTR */
308 current_thread_info()->restart_block.fn = do_no_restart_syscall;
310 err |= __get_user(regs->cp0_epc, &sc->sc_pc);
312 #ifdef CONFIG_CPU_HAS_SMARTMIPS
313 err |= __get_user(regs->acx, &sc->sc_acx);
315 err |= __get_user(regs->hi, &sc->sc_mdhi);
316 err |= __get_user(regs->lo, &sc->sc_mdlo);
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);
327 for (i = 1; i < 32; i++)
328 err |= __get_user(regs->regs[i], &sc->sc_regs[i]);
330 err |= __get_user(used_math, &sc->sc_used_math);
331 conditional_used_math(used_math);
334 /* restore fpu context if we have used it before */
336 err = check_and_restore_fp_context(sc, used_math);
338 /* signal handler may have used FPU or MSA. Disable them. */
346 void __user *get_sigframe(struct k_sigaction *ka, struct pt_regs *regs,
351 /* Default to using normal stack */
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.
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;
365 return (void __user *)((sp - frame_size) & (ICACHE_REFILLS_WORKAROUND_WAR ? ~(cpu_icache_line_size()-1) : ALMASK));
369 * Atomically swap in the new signal mask, and wait for a signal.
372 #ifdef CONFIG_TRAD_SIGNALS
373 SYSCALL_DEFINE1(sigsuspend, sigset_t __user *, uset)
375 return sys_rt_sigsuspend(uset, sizeof(sigset_t));
379 #ifdef CONFIG_TRAD_SIGNALS
380 SYSCALL_DEFINE3(sigaction, int, sig, const struct sigaction __user *, act,
381 struct sigaction __user *, oact)
383 struct k_sigaction new_ka, old_ka;
390 if (!access_ok(VERIFY_READ, act, sizeof(*act)))
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]);
398 siginitset(&new_ka.sa.sa_mask, mask);
401 ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL);
404 if (!access_ok(VERIFY_WRITE, oact, sizeof(*oact)))
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]);
420 #ifdef CONFIG_TRAD_SIGNALS
421 asmlinkage void sys_sigreturn(nabi_no_regargs struct pt_regs regs)
423 struct sigframe __user *frame;
427 frame = (struct sigframe __user *) regs.regs[29];
428 if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
430 if (__copy_from_user(&blocked, &frame->sf_mask, sizeof(blocked)))
433 set_current_blocked(&blocked);
435 sig = restore_sigcontext(®s, &frame->sf_sc);
439 force_sig(sig, current);
442 * Don't let your children do this ...
444 __asm__ __volatile__(
452 force_sig(SIGSEGV, current);
454 #endif /* CONFIG_TRAD_SIGNALS */
456 asmlinkage void sys_rt_sigreturn(nabi_no_regargs struct pt_regs regs)
458 struct rt_sigframe __user *frame;
462 frame = (struct rt_sigframe __user *) regs.regs[29];
463 if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
465 if (__copy_from_user(&set, &frame->rs_uc.uc_sigmask, sizeof(set)))
468 set_current_blocked(&set);
470 sig = restore_sigcontext(®s, &frame->rs_uc.uc_mcontext);
474 force_sig(sig, current);
476 if (restore_altstack(&frame->rs_uc.uc_stack))
480 * Don't let your children do this ...
482 __asm__ __volatile__(
490 force_sig(SIGSEGV, current);
493 #ifdef CONFIG_TRAD_SIGNALS
494 static int setup_frame(void *sig_return, struct k_sigaction *ka,
495 struct pt_regs *regs, int signr, sigset_t *set)
497 struct sigframe __user *frame;
500 frame = get_sigframe(ka, regs, sizeof(*frame));
501 if (!access_ok(VERIFY_WRITE, frame, sizeof (*frame)))
504 err |= setup_sigcontext(regs, &frame->sf_sc);
505 err |= __copy_to_user(&frame->sf_mask, set, sizeof(*set));
510 * Arguments to signal handler:
513 * a1 = 0 (should be cause)
514 * a2 = pointer to struct sigcontext
516 * $25 and c0_epc point to the signal handler, $29 points to the
519 regs->regs[ 4] = signr;
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;
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]);
532 force_sigsegv(signr, current);
537 static int setup_rt_frame(void *sig_return, struct k_sigaction *ka,
538 struct pt_regs *regs, int signr, sigset_t *set,
541 struct rt_sigframe __user *frame;
544 frame = get_sigframe(ka, regs, sizeof(*frame));
545 if (!access_ok(VERIFY_WRITE, frame, sizeof (*frame)))
548 /* Create siginfo. */
549 err |= copy_siginfo_to_user(&frame->rs_info, info);
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));
562 * Arguments to signal handler:
565 * a1 = 0 (should be cause)
566 * a2 = pointer to ucontext
568 * $25 and c0_epc point to the signal handler, $29 points to
569 * the struct rt_sigframe.
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;
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]);
585 force_sigsegv(signr, current);
589 struct mips_abi mips_abi = {
590 #ifdef CONFIG_TRAD_SIGNALS
591 .setup_frame = setup_frame,
592 .signal_return_offset = offsetof(struct mips_vdso, signal_trampoline),
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
600 static void handle_signal(unsigned long sig, siginfo_t *info,
601 struct k_sigaction *ka, struct pt_regs *regs)
603 sigset_t *oldset = sigmask_to_save();
605 struct mips_abi *abi = current->thread.abi;
606 #ifdef CONFIG_CPU_MICROMIPS
608 unsigned int tmp = (unsigned int)current->mm->context.vdso;
613 void *vdso = current->mm->context.vdso;
617 switch(regs->regs[2]) {
618 case ERESTART_RESTARTBLOCK:
620 regs->regs[2] = EINTR;
623 if (!(ka->sa.sa_flags & SA_RESTART)) {
624 regs->regs[2] = EINTR;
629 regs->regs[7] = regs->regs[26];
630 regs->regs[2] = regs->regs[0];
634 regs->regs[0] = 0; /* Don't deal with this again. */
637 if (sig_uses_siginfo(ka))
638 ret = abi->setup_rt_frame(vdso + abi->rt_signal_return_offset,
639 ka, regs, sig, oldset, info);
641 ret = abi->setup_frame(vdso + abi->signal_return_offset,
642 ka, regs, sig, oldset);
647 signal_delivered(sig, info, ka, regs, 0);
650 static void do_signal(struct pt_regs *regs)
652 struct k_sigaction ka;
656 signr = get_signal_to_deliver(&info, &ka, regs, NULL);
658 /* Whee! Actually deliver the signal. */
659 handle_signal(signr, &info, &ka, regs);
664 switch (regs->regs[2]) {
668 regs->regs[2] = regs->regs[0];
669 regs->regs[7] = regs->regs[26];
673 case ERESTART_RESTARTBLOCK:
674 regs->regs[2] = current->thread.abi->restart;
675 regs->regs[7] = regs->regs[26];
679 regs->regs[0] = 0; /* Don't deal with this again. */
683 * If there's no signal to deliver, we just put the saved sigmask
686 restore_saved_sigmask();
690 * notification of userspace execution resumption
691 * - triggered by the TIF_WORK_MASK flags
693 asmlinkage void do_notify_resume(struct pt_regs *regs, void *unused,
694 __u32 thread_info_flags)
700 /* deal with pending signal delivery */
701 if (thread_info_flags & _TIF_SIGPENDING)
704 if (thread_info_flags & _TIF_NOTIFY_RESUME) {
705 clear_thread_flag(TIF_NOTIFY_RESUME);
706 tracehook_notify_resume(regs);
714 static int smp_save_fp_context(struct sigcontext __user *sc)
716 return raw_cpu_has_fpu
717 ? _save_fp_context(sc)
718 : copy_fp_to_sigcontext(sc);
721 static int smp_restore_fp_context(struct sigcontext __user *sc)
723 return raw_cpu_has_fpu
724 ? _restore_fp_context(sc)
725 : copy_fp_from_sigcontext(sc);
727 #endif /* CONFIG_EVA */
730 static int signal_setup(void)
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;
739 save_fp_context = _save_fp_context;
740 restore_fp_context = _restore_fp_context;
742 save_fp_context = copy_fp_from_sigcontext;
743 restore_fp_context = copy_fp_to_sigcontext;
745 #endif /* CONFIG_SMP */
747 save_fp_context = copy_fp_from_sigcontext;;
748 restore_fp_context = copy_fp_to_sigcontext;
754 arch_initcall(signal_setup);