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/uprobes.h>
25 #include <linux/compiler.h>
26 #include <linux/syscalls.h>
27 #include <linux/uaccess.h>
28 #include <linux/tracehook.h>
32 #include <linux/bitops.h>
33 #include <asm/cacheflush.h>
36 #include <asm/ucontext.h>
37 #include <asm/cpu-features.h>
44 #include "signal-common.h"
46 static int (*save_fp_context)(void __user *sc);
47 static int (*restore_fp_context)(void __user *sc);
50 u32 sf_ass[4]; /* argument save space for o32 */
51 u32 sf_pad[2]; /* Was: signal trampoline */
53 /* Matches struct ucontext from its uc_mcontext field onwards */
54 struct sigcontext sf_sc;
56 unsigned long long sf_extcontext[0];
60 u32 rs_ass[4]; /* argument save space for o32 */
61 u32 rs_pad[2]; /* Was: signal trampoline */
62 struct siginfo rs_info;
63 struct ucontext rs_uc;
67 * Thread saved context copy to/from a signal context presumed to be on the
68 * user stack, and therefore accessed with appropriate macros from uaccess.h.
70 static int copy_fp_to_sigcontext(void __user *sc)
72 struct mips_abi *abi = current->thread.abi;
73 uint64_t __user *fpregs = sc + abi->off_sc_fpregs;
74 uint32_t __user *csr = sc + abi->off_sc_fpc_csr;
77 int inc = test_thread_flag(TIF_32BIT_FPREGS) ? 2 : 1;
79 for (i = 0; i < NUM_FPU_REGS; i += inc) {
81 __put_user(get_fpr64(¤t->thread.fpu.fpr[i], 0),
84 err |= __put_user(current->thread.fpu.fcr31, csr);
89 static int copy_fp_from_sigcontext(void __user *sc)
91 struct mips_abi *abi = current->thread.abi;
92 uint64_t __user *fpregs = sc + abi->off_sc_fpregs;
93 uint32_t __user *csr = sc + abi->off_sc_fpc_csr;
96 int inc = test_thread_flag(TIF_32BIT_FPREGS) ? 2 : 1;
99 for (i = 0; i < NUM_FPU_REGS; i += inc) {
100 err |= __get_user(fpr_val, &fpregs[i]);
101 set_fpr64(¤t->thread.fpu.fpr[i], 0, fpr_val);
103 err |= __get_user(current->thread.fpu.fcr31, csr);
109 * Wrappers for the assembly _{save,restore}_fp_context functions.
111 static int save_hw_fp_context(void __user *sc)
113 struct mips_abi *abi = current->thread.abi;
114 uint64_t __user *fpregs = sc + abi->off_sc_fpregs;
115 uint32_t __user *csr = sc + abi->off_sc_fpc_csr;
117 return _save_fp_context(fpregs, csr);
120 static int restore_hw_fp_context(void __user *sc)
122 struct mips_abi *abi = current->thread.abi;
123 uint64_t __user *fpregs = sc + abi->off_sc_fpregs;
124 uint32_t __user *csr = sc + abi->off_sc_fpc_csr;
126 return _restore_fp_context(fpregs, csr);
130 * Extended context handling.
133 static inline void __user *sc_to_extcontext(void __user *sc)
135 struct ucontext __user *uc;
138 * We can just pretend the sigcontext is always embedded in a struct
139 * ucontext here, because the offset from sigcontext to extended
140 * context is the same in the struct sigframe case.
142 uc = container_of(sc, struct ucontext, uc_mcontext);
143 return &uc->uc_extcontext;
146 static int save_msa_extcontext(void __user *buf)
148 struct msa_extcontext __user *msa = buf;
152 if (!thread_msa_context_live())
156 * Ensure that we can't lose the live MSA context between checking
157 * for it & writing it to memory.
161 if (is_msa_enabled()) {
163 * There are no EVA versions of the vector register load/store
164 * instructions, so MSA context has to be saved to kernel memory
165 * and then copied to user memory. The save to kernel memory
166 * should already have been done when handling scalar FP
169 BUG_ON(config_enabled(CONFIG_EVA));
171 err = __put_user(read_msa_csr(), &msa->csr);
172 err |= _save_msa_all_upper(&msa->wr);
178 err = __put_user(current->thread.fpu.msacsr, &msa->csr);
180 for (i = 0; i < NUM_FPU_REGS; i++) {
181 val = get_fpr64(¤t->thread.fpu.fpr[i], 1);
182 err |= __put_user(val, &msa->wr[i]);
186 err |= __put_user(MSA_EXTCONTEXT_MAGIC, &msa->ext.magic);
187 err |= __put_user(sizeof(*msa), &msa->ext.size);
189 return err ? -EFAULT : sizeof(*msa);
192 static int restore_msa_extcontext(void __user *buf, unsigned int size)
194 struct msa_extcontext __user *msa = buf;
195 unsigned long long val;
199 if (size != sizeof(*msa))
202 err = get_user(csr, &msa->csr);
208 if (is_msa_enabled()) {
210 * There are no EVA versions of the vector register load/store
211 * instructions, so MSA context has to be copied to kernel
212 * memory and later loaded to registers. The same is true of
213 * scalar FP context, so FPU & MSA should have already been
214 * disabled whilst handling scalar FP context.
216 BUG_ON(config_enabled(CONFIG_EVA));
219 err |= _restore_msa_all_upper(&msa->wr);
224 current->thread.fpu.msacsr = csr;
226 for (i = 0; i < NUM_FPU_REGS; i++) {
227 err |= __get_user(val, &msa->wr[i]);
228 set_fpr64(¤t->thread.fpu.fpr[i], 1, val);
235 static int save_extcontext(void __user *buf)
239 sz = save_msa_extcontext(buf);
244 /* If no context was saved then trivially return */
248 /* Write the end marker */
249 if (__put_user(END_EXTCONTEXT_MAGIC, (u32 *)buf))
252 sz += sizeof(((struct extcontext *)NULL)->magic);
256 static int restore_extcontext(void __user *buf)
258 struct extcontext ext;
262 err = __get_user(ext.magic, (unsigned int *)buf);
266 if (ext.magic == END_EXTCONTEXT_MAGIC)
269 err = __get_user(ext.size, (unsigned int *)(buf
270 + offsetof(struct extcontext, size)));
275 case MSA_EXTCONTEXT_MAGIC:
276 err = restore_msa_extcontext(buf, ext.size);
294 int protected_save_fp_context(void __user *sc)
296 struct mips_abi *abi = current->thread.abi;
297 uint64_t __user *fpregs = sc + abi->off_sc_fpregs;
298 uint32_t __user *csr = sc + abi->off_sc_fpc_csr;
299 uint32_t __user *used_math = sc + abi->off_sc_used_math;
300 unsigned int used, ext_sz;
303 used = used_math() ? USED_FP : 0;
307 if (!test_thread_flag(TIF_32BIT_FPREGS))
309 if (test_thread_flag(TIF_HYBRID_FPREGS))
310 used |= USED_HYBRID_FPRS;
313 * EVA does not have userland equivalents of ldc1 or sdc1, so
314 * save to the kernel FP context & copy that to userland below.
316 if (config_enabled(CONFIG_EVA))
321 if (is_fpu_owner()) {
322 err = save_fp_context(sc);
326 err = copy_fp_to_sigcontext(sc);
330 /* touch the sigcontext and try again */
331 err = __put_user(0, &fpregs[0]) |
332 __put_user(0, &fpregs[31]) |
335 return err; /* really bad sigcontext */
339 ext_sz = err = save_extcontext(sc_to_extcontext(sc));
342 used |= ext_sz ? USED_EXTCONTEXT : 0;
344 return __put_user(used, used_math);
347 int protected_restore_fp_context(void __user *sc)
349 struct mips_abi *abi = current->thread.abi;
350 uint64_t __user *fpregs = sc + abi->off_sc_fpregs;
351 uint32_t __user *csr = sc + abi->off_sc_fpc_csr;
352 uint32_t __user *used_math = sc + abi->off_sc_used_math;
354 int err, sig = 0, tmp __maybe_unused;
356 err = __get_user(used, used_math);
357 conditional_used_math(used & USED_FP);
360 * The signal handler may have used FPU; give it up if the program
361 * doesn't want it following sigreturn.
363 if (err || !(used & USED_FP))
367 if (!(used & USED_FP))
370 err = sig = fpcsr_pending(csr);
375 * EVA does not have userland equivalents of ldc1 or sdc1, so we
376 * disable the FPU here such that the code below simply copies to
377 * the kernel FP context.
379 if (config_enabled(CONFIG_EVA))
384 if (is_fpu_owner()) {
385 err = restore_fp_context(sc);
389 err = copy_fp_from_sigcontext(sc);
393 /* touch the sigcontext and try again */
394 err = __get_user(tmp, &fpregs[0]) |
395 __get_user(tmp, &fpregs[31]) |
396 __get_user(tmp, csr);
398 break; /* really bad sigcontext */
402 if (used & USED_EXTCONTEXT)
403 err |= restore_extcontext(sc_to_extcontext(sc));
408 int setup_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc)
413 err |= __put_user(regs->cp0_epc, &sc->sc_pc);
415 err |= __put_user(0, &sc->sc_regs[0]);
416 for (i = 1; i < 32; i++)
417 err |= __put_user(regs->regs[i], &sc->sc_regs[i]);
419 #ifdef CONFIG_CPU_HAS_SMARTMIPS
420 err |= __put_user(regs->acx, &sc->sc_acx);
422 err |= __put_user(regs->hi, &sc->sc_mdhi);
423 err |= __put_user(regs->lo, &sc->sc_mdlo);
425 err |= __put_user(mfhi1(), &sc->sc_hi1);
426 err |= __put_user(mflo1(), &sc->sc_lo1);
427 err |= __put_user(mfhi2(), &sc->sc_hi2);
428 err |= __put_user(mflo2(), &sc->sc_lo2);
429 err |= __put_user(mfhi3(), &sc->sc_hi3);
430 err |= __put_user(mflo3(), &sc->sc_lo3);
431 err |= __put_user(rddsp(DSP_MASK), &sc->sc_dsp);
436 * Save FPU state to signal context. Signal handler
437 * will "inherit" current FPU state.
439 err |= protected_save_fp_context(sc);
444 static size_t extcontext_max_size(void)
449 * The assumption here is that between this point & the point at which
450 * the extended context is saved the size of the context should only
451 * ever be able to shrink (if the task is preempted), but never grow.
452 * That is, what this function returns is an upper bound on the size of
453 * the extended context for the current task at the current time.
456 if (thread_msa_context_live())
457 sz += sizeof(struct msa_extcontext);
459 /* If any context is saved then we'll append the end marker */
461 sz += sizeof(((struct extcontext *)NULL)->magic);
466 int fpcsr_pending(unsigned int __user *fpcsr)
469 unsigned int csr, enabled;
471 err = __get_user(csr, fpcsr);
472 enabled = FPU_CSR_UNI_X | ((csr & FPU_CSR_ALL_E) << 5);
474 * If the signal handler set some FPU exceptions, clear it and
479 err |= __put_user(csr, fpcsr);
485 int restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc)
491 /* Always make any pending restarted system calls return -EINTR */
492 current->restart_block.fn = do_no_restart_syscall;
494 err |= __get_user(regs->cp0_epc, &sc->sc_pc);
496 #ifdef CONFIG_CPU_HAS_SMARTMIPS
497 err |= __get_user(regs->acx, &sc->sc_acx);
499 err |= __get_user(regs->hi, &sc->sc_mdhi);
500 err |= __get_user(regs->lo, &sc->sc_mdlo);
502 err |= __get_user(treg, &sc->sc_hi1); mthi1(treg);
503 err |= __get_user(treg, &sc->sc_lo1); mtlo1(treg);
504 err |= __get_user(treg, &sc->sc_hi2); mthi2(treg);
505 err |= __get_user(treg, &sc->sc_lo2); mtlo2(treg);
506 err |= __get_user(treg, &sc->sc_hi3); mthi3(treg);
507 err |= __get_user(treg, &sc->sc_lo3); mtlo3(treg);
508 err |= __get_user(treg, &sc->sc_dsp); wrdsp(treg, DSP_MASK);
511 for (i = 1; i < 32; i++)
512 err |= __get_user(regs->regs[i], &sc->sc_regs[i]);
514 return err ?: protected_restore_fp_context(sc);
517 void __user *get_sigframe(struct ksignal *ksig, struct pt_regs *regs,
522 /* Leave space for potential extended context */
523 frame_size += extcontext_max_size();
525 /* Default to using normal stack */
529 * FPU emulator may have it's own trampoline active just
530 * above the user stack, 16-bytes before the next lowest
531 * 16 byte boundary. Try to avoid trashing it.
535 sp = sigsp(sp, ksig);
537 return (void __user *)((sp - frame_size) & (ICACHE_REFILLS_WORKAROUND_WAR ? ~(cpu_icache_line_size()-1) : ALMASK));
541 * Atomically swap in the new signal mask, and wait for a signal.
544 #ifdef CONFIG_TRAD_SIGNALS
545 SYSCALL_DEFINE1(sigsuspend, sigset_t __user *, uset)
547 return sys_rt_sigsuspend(uset, sizeof(sigset_t));
551 #ifdef CONFIG_TRAD_SIGNALS
552 SYSCALL_DEFINE3(sigaction, int, sig, const struct sigaction __user *, act,
553 struct sigaction __user *, oact)
555 struct k_sigaction new_ka, old_ka;
562 if (!access_ok(VERIFY_READ, act, sizeof(*act)))
564 err |= __get_user(new_ka.sa.sa_handler, &act->sa_handler);
565 err |= __get_user(new_ka.sa.sa_flags, &act->sa_flags);
566 err |= __get_user(mask, &act->sa_mask.sig[0]);
570 siginitset(&new_ka.sa.sa_mask, mask);
573 ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL);
576 if (!access_ok(VERIFY_WRITE, oact, sizeof(*oact)))
578 err |= __put_user(old_ka.sa.sa_flags, &oact->sa_flags);
579 err |= __put_user(old_ka.sa.sa_handler, &oact->sa_handler);
580 err |= __put_user(old_ka.sa.sa_mask.sig[0], oact->sa_mask.sig);
581 err |= __put_user(0, &oact->sa_mask.sig[1]);
582 err |= __put_user(0, &oact->sa_mask.sig[2]);
583 err |= __put_user(0, &oact->sa_mask.sig[3]);
592 #ifdef CONFIG_TRAD_SIGNALS
593 asmlinkage void sys_sigreturn(nabi_no_regargs struct pt_regs regs)
595 struct sigframe __user *frame;
599 frame = (struct sigframe __user *) regs.regs[29];
600 if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
602 if (__copy_from_user(&blocked, &frame->sf_mask, sizeof(blocked)))
605 set_current_blocked(&blocked);
607 sig = restore_sigcontext(®s, &frame->sf_sc);
611 force_sig(sig, current);
614 * Don't let your children do this ...
616 __asm__ __volatile__(
624 force_sig(SIGSEGV, current);
626 #endif /* CONFIG_TRAD_SIGNALS */
628 asmlinkage void sys_rt_sigreturn(nabi_no_regargs struct pt_regs regs)
630 struct rt_sigframe __user *frame;
634 frame = (struct rt_sigframe __user *) regs.regs[29];
635 if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
637 if (__copy_from_user(&set, &frame->rs_uc.uc_sigmask, sizeof(set)))
640 set_current_blocked(&set);
642 sig = restore_sigcontext(®s, &frame->rs_uc.uc_mcontext);
646 force_sig(sig, current);
648 if (restore_altstack(&frame->rs_uc.uc_stack))
652 * Don't let your children do this ...
654 __asm__ __volatile__(
662 force_sig(SIGSEGV, current);
665 #ifdef CONFIG_TRAD_SIGNALS
666 static int setup_frame(void *sig_return, struct ksignal *ksig,
667 struct pt_regs *regs, sigset_t *set)
669 struct sigframe __user *frame;
672 frame = get_sigframe(ksig, regs, sizeof(*frame));
673 if (!access_ok(VERIFY_WRITE, frame, sizeof (*frame)))
676 err |= setup_sigcontext(regs, &frame->sf_sc);
677 err |= __copy_to_user(&frame->sf_mask, set, sizeof(*set));
682 * Arguments to signal handler:
685 * a1 = 0 (should be cause)
686 * a2 = pointer to struct sigcontext
688 * $25 and c0_epc point to the signal handler, $29 points to the
691 regs->regs[ 4] = ksig->sig;
693 regs->regs[ 6] = (unsigned long) &frame->sf_sc;
694 regs->regs[29] = (unsigned long) frame;
695 regs->regs[31] = (unsigned long) sig_return;
696 regs->cp0_epc = regs->regs[25] = (unsigned long) ksig->ka.sa.sa_handler;
698 DEBUGP("SIG deliver (%s:%d): sp=0x%p pc=0x%lx ra=0x%lx\n",
699 current->comm, current->pid,
700 frame, regs->cp0_epc, regs->regs[31]);
705 static int setup_rt_frame(void *sig_return, struct ksignal *ksig,
706 struct pt_regs *regs, sigset_t *set)
708 struct rt_sigframe __user *frame;
711 frame = get_sigframe(ksig, regs, sizeof(*frame));
712 if (!access_ok(VERIFY_WRITE, frame, sizeof (*frame)))
715 /* Create siginfo. */
716 err |= copy_siginfo_to_user(&frame->rs_info, &ksig->info);
718 /* Create the ucontext. */
719 err |= __put_user(0, &frame->rs_uc.uc_flags);
720 err |= __put_user(NULL, &frame->rs_uc.uc_link);
721 err |= __save_altstack(&frame->rs_uc.uc_stack, regs->regs[29]);
722 err |= setup_sigcontext(regs, &frame->rs_uc.uc_mcontext);
723 err |= __copy_to_user(&frame->rs_uc.uc_sigmask, set, sizeof(*set));
729 * Arguments to signal handler:
732 * a1 = 0 (should be cause)
733 * a2 = pointer to ucontext
735 * $25 and c0_epc point to the signal handler, $29 points to
736 * the struct rt_sigframe.
738 regs->regs[ 4] = ksig->sig;
739 regs->regs[ 5] = (unsigned long) &frame->rs_info;
740 regs->regs[ 6] = (unsigned long) &frame->rs_uc;
741 regs->regs[29] = (unsigned long) frame;
742 regs->regs[31] = (unsigned long) sig_return;
743 regs->cp0_epc = regs->regs[25] = (unsigned long) ksig->ka.sa.sa_handler;
745 DEBUGP("SIG deliver (%s:%d): sp=0x%p pc=0x%lx ra=0x%lx\n",
746 current->comm, current->pid,
747 frame, regs->cp0_epc, regs->regs[31]);
752 struct mips_abi mips_abi = {
753 #ifdef CONFIG_TRAD_SIGNALS
754 .setup_frame = setup_frame,
755 .signal_return_offset = offsetof(struct mips_vdso, signal_trampoline),
757 .setup_rt_frame = setup_rt_frame,
758 .rt_signal_return_offset =
759 offsetof(struct mips_vdso, rt_signal_trampoline),
760 .restart = __NR_restart_syscall,
762 .off_sc_fpregs = offsetof(struct sigcontext, sc_fpregs),
763 .off_sc_fpc_csr = offsetof(struct sigcontext, sc_fpc_csr),
764 .off_sc_used_math = offsetof(struct sigcontext, sc_used_math),
767 static void handle_signal(struct ksignal *ksig, struct pt_regs *regs)
769 sigset_t *oldset = sigmask_to_save();
771 struct mips_abi *abi = current->thread.abi;
772 #ifdef CONFIG_CPU_MICROMIPS
774 unsigned long tmp = (unsigned long)current->mm->context.vdso;
779 void *vdso = current->mm->context.vdso;
783 switch(regs->regs[2]) {
784 case ERESTART_RESTARTBLOCK:
786 regs->regs[2] = EINTR;
789 if (!(ksig->ka.sa.sa_flags & SA_RESTART)) {
790 regs->regs[2] = EINTR;
795 regs->regs[7] = regs->regs[26];
796 regs->regs[2] = regs->regs[0];
800 regs->regs[0] = 0; /* Don't deal with this again. */
803 if (sig_uses_siginfo(&ksig->ka))
804 ret = abi->setup_rt_frame(vdso + abi->rt_signal_return_offset,
807 ret = abi->setup_frame(vdso + abi->signal_return_offset, ksig,
810 signal_setup_done(ret, ksig, 0);
813 static void do_signal(struct pt_regs *regs)
817 if (get_signal(&ksig)) {
818 /* Whee! Actually deliver the signal. */
819 handle_signal(&ksig, regs);
824 switch (regs->regs[2]) {
828 regs->regs[2] = regs->regs[0];
829 regs->regs[7] = regs->regs[26];
833 case ERESTART_RESTARTBLOCK:
834 regs->regs[2] = current->thread.abi->restart;
835 regs->regs[7] = regs->regs[26];
839 regs->regs[0] = 0; /* Don't deal with this again. */
843 * If there's no signal to deliver, we just put the saved sigmask
846 restore_saved_sigmask();
850 * notification of userspace execution resumption
851 * - triggered by the TIF_WORK_MASK flags
853 asmlinkage void do_notify_resume(struct pt_regs *regs, void *unused,
854 __u32 thread_info_flags)
860 if (thread_info_flags & _TIF_UPROBE)
861 uprobe_notify_resume(regs);
863 /* deal with pending signal delivery */
864 if (thread_info_flags & _TIF_SIGPENDING)
867 if (thread_info_flags & _TIF_NOTIFY_RESUME) {
868 clear_thread_flag(TIF_NOTIFY_RESUME);
869 tracehook_notify_resume(regs);
876 static int smp_save_fp_context(void __user *sc)
878 return raw_cpu_has_fpu
879 ? save_hw_fp_context(sc)
880 : copy_fp_to_sigcontext(sc);
883 static int smp_restore_fp_context(void __user *sc)
885 return raw_cpu_has_fpu
886 ? restore_hw_fp_context(sc)
887 : copy_fp_from_sigcontext(sc);
891 static int signal_setup(void)
894 * The offset from sigcontext to extended context should be the same
895 * regardless of the type of signal, such that userland can always know
896 * where to look if it wishes to find the extended context structures.
898 BUILD_BUG_ON((offsetof(struct sigframe, sf_extcontext) -
899 offsetof(struct sigframe, sf_sc)) !=
900 (offsetof(struct rt_sigframe, rs_uc.uc_extcontext) -
901 offsetof(struct rt_sigframe, rs_uc.uc_mcontext)));
904 /* For now just do the cpu_has_fpu check when the functions are invoked */
905 save_fp_context = smp_save_fp_context;
906 restore_fp_context = smp_restore_fp_context;
909 save_fp_context = save_hw_fp_context;
910 restore_fp_context = restore_hw_fp_context;
912 save_fp_context = copy_fp_to_sigcontext;
913 restore_fp_context = copy_fp_from_sigcontext;
915 #endif /* CONFIG_SMP */
920 arch_initcall(signal_setup);