/* * linux/arch/m68knommu/kernel/signal.c * * Copyright (C) 1991, 1992 Linus Torvalds * * This file is subject to the terms and conditions of the GNU General Public * License. See the file COPYING in the main directory of this archive * for more details. */ /* * Linux/m68k support by Hamish Macdonald * * 68060 fixes by Jesper Skov * * 1997-12-01 Modified for POSIX.1b signals by Andreas Schwab * * mathemu support by Roman Zippel * (Note: fpstate in the signal context is completely ignored for the emulator * and the internal floating point format is put on stack) */ /* * ++roman (07/09/96): implemented signal stacks (specially for tosemu on * Atari :-) Current limitation: Only one sigstack can be active at one time. * If a second signal with SA_ONSTACK set arrives while working on a sigstack, * SA_ONSTACK is ignored. This behaviour avoids lots of trouble with nested * signal handlers! */ #include <linux/sched.h> #include <linux/mm.h> #include <linux/kernel.h> #include <linux/signal.h> #include <linux/syscalls.h> #include <linux/errno.h> #include <linux/wait.h> #include <linux/ptrace.h> #include <linux/unistd.h> #include <linux/stddef.h> #include <linux/highuid.h> #include <linux/tty.h> #include <linux/personality.h> #include <linux/binfmts.h> #include <asm/setup.h> #include <asm/uaccess.h> #include <asm/pgtable.h> #include <asm/traps.h> #include <asm/ucontext.h> #define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP))) asmlinkage int do_signal(sigset_t *oldset, struct pt_regs *regs); /* * Atomically swap in the new signal mask, and wait for a signal. */ asmlinkage int do_sigsuspend(struct pt_regs *regs) { old_sigset_t mask = regs->d3; sigset_t saveset; mask &= _BLOCKABLE; spin_lock_irq(¤t->sighand->siglock); saveset = current->blocked; siginitset(¤t->blocked, mask); recalc_sigpending(); spin_unlock_irq(¤t->sighand->siglock); regs->d0 = -EINTR; while (1) { current->state = TASK_INTERRUPTIBLE; schedule(); if (do_signal(&saveset, regs)) return -EINTR; } } asmlinkage int do_rt_sigsuspend(struct pt_regs *regs) { sigset_t *unewset = (sigset_t *)regs->d1; size_t sigsetsize = (size_t)regs->d2; sigset_t saveset, newset; /* XXX: Don't preclude handling different sized sigset_t's. */ if (sigsetsize != sizeof(sigset_t)) return -EINVAL; if (copy_from_user(&newset, unewset, sizeof(newset))) return -EFAULT; sigdelsetmask(&newset, ~_BLOCKABLE); spin_lock_irq(¤t->sighand->siglock); saveset = current->blocked; current->blocked = newset; recalc_sigpending(); spin_unlock_irq(¤t->sighand->siglock); regs->d0 = -EINTR; while (1) { current->state = TASK_INTERRUPTIBLE; schedule(); if (do_signal(&saveset, regs)) return -EINTR; } } asmlinkage int sys_sigaction(int sig, const struct old_sigaction *act, struct old_sigaction *oact) { struct k_sigaction new_ka, old_ka; int ret; if (act) { old_sigset_t mask; if (!access_ok(VERIFY_READ, act, sizeof(*act)) || __get_user(new_ka.sa.sa_handler, &act->sa_handler) || __get_user(new_ka.sa.sa_restorer, &act->sa_restorer)) return -EFAULT; __get_user(new_ka.sa.sa_flags, &act->sa_flags); __get_user(mask, &act->sa_mask); siginitset(&new_ka.sa.sa_mask, mask); } ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL); if (!ret && oact) { if (!access_ok(VERIFY_WRITE, oact, sizeof(*oact)) || __put_user(old_ka.sa.sa_handler, &oact->sa_handler) || __put_user(old_ka.sa.sa_restorer, &oact->sa_restorer)) return -EFAULT; __put_user(old_ka.sa.sa_flags, &oact->sa_flags); __put_user(old_ka.sa.sa_mask.sig[0], &oact->sa_mask); } return ret; } asmlinkage int sys_sigaltstack(const stack_t *uss, stack_t *uoss) { return do_sigaltstack(uss, uoss, rdusp()); } /* * Do a signal return; undo the signal stack. * * Keep the return code on the stack quadword aligned! * That makes the cache flush below easier. */ struct sigframe { char *pretcode; int sig; int code; struct sigcontext *psc; char retcode[8]; unsigned long extramask[_NSIG_WORDS-1]; struct sigcontext sc; }; struct rt_sigframe { char *pretcode; int sig; struct siginfo *pinfo; void *puc; char retcode[8]; struct siginfo info; struct ucontext uc; }; #ifdef CONFIG_FPU static unsigned char fpu_version = 0; /* version number of fpu, set by setup_frame */ static inline int restore_fpu_state(struct sigcontext *sc) { int err = 1; if (FPU_IS_EMU) { /* restore registers */ memcpy(current->thread.fpcntl, sc->sc_fpcntl, 12); memcpy(current->thread.fp, sc->sc_fpregs, 24); return 0; } if (sc->sc_fpstate[0]) { /* Verify the frame format. */ if (sc->sc_fpstate[0] != fpu_version) goto out; __asm__ volatile (".chip 68k/68881\n\t" "fmovemx %0,%/fp0-%/fp1\n\t" "fmoveml %1,%/fpcr/%/fpsr/%/fpiar\n\t" ".chip 68k" : /* no outputs */ : "m" (*sc->sc_fpregs), "m" (*sc->sc_fpcntl)); } __asm__ volatile (".chip 68k/68881\n\t" "frestore %0\n\t" ".chip 68k" : : "m" (*sc->sc_fpstate)); err = 0; out: return err; } #define FPCONTEXT_SIZE 216 #define uc_fpstate uc_filler[0] #define uc_formatvec uc_filler[FPCONTEXT_SIZE/4] #define uc_extra uc_filler[FPCONTEXT_SIZE/4+1] static inline int rt_restore_fpu_state(struct ucontext *uc) { unsigned char fpstate[FPCONTEXT_SIZE]; int context_size = 0; fpregset_t fpregs; int err = 1; if (FPU_IS_EMU) { /* restore fpu control register */ if (__copy_from_user(current->thread.fpcntl, &uc->uc_mcontext.fpregs.f_pcr, 12)) goto out; /* restore all other fpu register */ if (__copy_from_user(current->thread.fp, uc->uc_mcontext.fpregs.f_fpregs, 96)) goto out; return 0; } if (__get_user(*(long *)fpstate, (long *)&uc->uc_fpstate)) goto out; if (fpstate[0]) { context_size = fpstate[1]; /* Verify the frame format. */ if (fpstate[0] != fpu_version) goto out; if (__copy_from_user(&fpregs, &uc->uc_mcontext.fpregs, sizeof(fpregs))) goto out; __asm__ volatile (".chip 68k/68881\n\t" "fmovemx %0,%/fp0-%/fp7\n\t" "fmoveml %1,%/fpcr/%/fpsr/%/fpiar\n\t" ".chip 68k" : /* no outputs */ : "m" (*fpregs.f_fpregs), "m" (fpregs.f_pcr)); } if (context_size && __copy_from_user(fpstate + 4, (long *)&uc->uc_fpstate + 1, context_size)) goto out; __asm__ volatile (".chip 68k/68881\n\t" "frestore %0\n\t" ".chip 68k" : : "m" (*fpstate)); err = 0; out: return err; } #endif static inline int restore_sigcontext(struct pt_regs *regs, struct sigcontext *usc, void *fp, int *pd0) { int formatvec; struct sigcontext context; int err = 0; /* get previous context */ if (copy_from_user(&context, usc, sizeof(context))) goto badframe; /* restore passed registers */ regs->d1 = context.sc_d1; regs->a0 = context.sc_a0; regs->a1 = context.sc_a1; ((struct switch_stack *)regs - 1)->a5 = context.sc_a5; regs->sr = (regs->sr & 0xff00) | (context.sc_sr & 0xff); regs->pc = context.sc_pc; regs->orig_d0 = -1; /* disable syscall checks */ wrusp(context.sc_usp); formatvec = context.sc_formatvec; regs->format = formatvec >> 12; regs->vector = formatvec & 0xfff; #ifdef CONFIG_FPU err = restore_fpu_state(&context); #endif *pd0 = context.sc_d0; return err; badframe: return 1; } static inline int rt_restore_ucontext(struct pt_regs *regs, struct switch_stack *sw, struct ucontext *uc, int *pd0) { int temp; greg_t *gregs = uc->uc_mcontext.gregs; unsigned long usp; int err; err = __get_user(temp, &uc->uc_mcontext.version); if (temp != MCONTEXT_VERSION) goto badframe; /* restore passed registers */ err |= __get_user(regs->d0, &gregs[0]); err |= __get_user(regs->d1, &gregs[1]); err |= __get_user(regs->d2, &gregs[2]); err |= __get_user(regs->d3, &gregs[3]); err |= __get_user(regs->d4, &gregs[4]); err |= __get_user(regs->d5, &gregs[5]); err |= __get_user(sw->d6, &gregs[6]); err |= __get_user(sw->d7, &gregs[7]); err |= __get_user(regs->a0, &gregs[8]); err |= __get_user(regs->a1, &gregs[9]); err |= __get_user(regs->a2, &gregs[10]); err |= __get_user(sw->a3, &gregs[11]); err |= __get_user(sw->a4, &gregs[12]); err |= __get_user(sw->a5, &gregs[13]); err |= __get_user(sw->a6, &gregs[14]); err |= __get_user(usp, &gregs[15]); wrusp(usp); err |= __get_user(regs->pc, &gregs[16]); err |= __get_user(temp, &gregs[17]); regs->sr = (regs->sr & 0xff00) | (temp & 0xff); regs->orig_d0 = -1; /* disable syscall checks */ regs->format = temp >> 12; regs->vector = temp & 0xfff; if (do_sigaltstack(&uc->uc_stack, NULL, usp) == -EFAULT) goto badframe; *pd0 = regs->d0; return err; badframe: return 1; } asmlinkage int do_sigreturn(unsigned long __unused) { struct switch_stack *sw = (struct switch_stack *) &__unused; struct pt_regs *regs = (struct pt_regs *) (sw + 1); unsigned long usp = rdusp(); struct sigframe *frame = (struct sigframe *)(usp - 4); sigset_t set; int d0; if (!access_ok(VERIFY_READ, frame, sizeof(*frame))) goto badframe; if (__get_user(set.sig[0], &frame->sc.sc_mask) || (_NSIG_WORDS > 1 && __copy_from_user(&set.sig[1], &frame->extramask, sizeof(frame->extramask)))) goto badframe; sigdelsetmask(&set, ~_BLOCKABLE); spin_lock_irq(¤t->sighand->siglock); current->blocked = set; recalc_sigpending(); spin_unlock_irq(¤t->sighand->siglock); if (restore_sigcontext(regs, &frame->sc, frame + 1, &d0)) goto badframe; return d0; badframe: force_sig(SIGSEGV, current); return 0; } asmlinkage int do_rt_sigreturn(unsigned long __unused) { struct switch_stack *sw = (struct switch_stack *) &__unused; struct pt_regs *regs = (struct pt_regs *) (sw + 1); unsigned long usp = rdusp(); struct rt_sigframe *frame = (struct rt_sigframe *)(usp - 4); sigset_t set; int d0; if (!access_ok(VERIFY_READ, frame, sizeof(*frame))) goto badframe; if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set))) goto badframe; sigdelsetmask(&set, ~_BLOCKABLE); spin_lock_irq(¤t->sighand->siglock); current->blocked = set; recalc_sigpending(); spin_unlock_irq(¤t->sighand->siglock); if (rt_restore_ucontext(regs, sw, &frame->uc, &d0)) goto badframe; return d0; badframe: force_sig(SIGSEGV, current); return 0; } #ifdef CONFIG_FPU /* * Set up a signal frame. */ static inline void save_fpu_state(struct sigcontext *sc, struct pt_regs *regs) { if (FPU_IS_EMU) { /* save registers */ memcpy(sc->sc_fpcntl, current->thread.fpcntl, 12); memcpy(sc->sc_fpregs, current->thread.fp, 24); return; } __asm__ volatile (".chip 68k/68881\n\t" "fsave %0\n\t" ".chip 68k" : : "m" (*sc->sc_fpstate) : "memory"); if (sc->sc_fpstate[0]) { fpu_version = sc->sc_fpstate[0]; __asm__ volatile (".chip 68k/68881\n\t" "fmovemx %/fp0-%/fp1,%0\n\t" "fmoveml %/fpcr/%/fpsr/%/fpiar,%1\n\t" ".chip 68k" : /* no outputs */ : "m" (*sc->sc_fpregs), "m" (*sc->sc_fpcntl) : "memory"); } } static inline int rt_save_fpu_state(struct ucontext *uc, struct pt_regs *regs) { unsigned char fpstate[FPCONTEXT_SIZE]; int context_size = 0; int err = 0; if (FPU_IS_EMU) { /* save fpu control register */ err |= copy_to_user(&uc->uc_mcontext.fpregs.f_pcr, current->thread.fpcntl, 12); /* save all other fpu register */ err |= copy_to_user(uc->uc_mcontext.fpregs.f_fpregs, current->thread.fp, 96); return err; } __asm__ volatile (".chip 68k/68881\n\t" "fsave %0\n\t" ".chip 68k" : : "m" (*fpstate) : "memory"); err |= __put_user(*(long *)fpstate, (long *)&uc->uc_fpstate); if (fpstate[0]) { fpregset_t fpregs; context_size = fpstate[1]; fpu_version = fpstate[0]; __asm__ volatile (".chip 68k/68881\n\t" "fmovemx %/fp0-%/fp7,%0\n\t" "fmoveml %/fpcr/%/fpsr/%/fpiar,%1\n\t" ".chip 68k" : /* no outputs */ : "m" (*fpregs.f_fpregs), "m" (fpregs.f_pcr) : "memory"); err |= copy_to_user(&uc->uc_mcontext.fpregs, &fpregs, sizeof(fpregs)); } if (context_size) err |= copy_to_user((long *)&uc->uc_fpstate + 1, fpstate + 4, context_size); return err; } #endif static void setup_sigcontext(struct sigcontext *sc, struct pt_regs *regs, unsigned long mask) { sc->sc_mask = mask; sc->sc_usp = rdusp(); sc->sc_d0 = regs->d0; sc->sc_d1 = regs->d1; sc->sc_a0 = regs->a0; sc->sc_a1 = regs->a1; sc->sc_a5 = ((struct switch_stack *)regs - 1)->a5; sc->sc_sr = regs->sr; sc->sc_pc = regs->pc; sc->sc_formatvec = regs->format << 12 | regs->vector; #ifdef CONFIG_FPU save_fpu_state(sc, regs); #endif } static inline int rt_setup_ucontext(struct ucontext *uc, struct pt_regs *regs) { struct switch_stack *sw = (struct switch_stack *)regs - 1; greg_t *gregs = uc->uc_mcontext.gregs; int err = 0; err |= __put_user(MCONTEXT_VERSION, &uc->uc_mcontext.version); err |= __put_user(regs->d0, &gregs[0]); err |= __put_user(regs->d1, &gregs[1]); err |= __put_user(regs->d2, &gregs[2]); err |= __put_user(regs->d3, &gregs[3]); err |= __put_user(regs->d4, &gregs[4]); err |= __put_user(regs->d5, &gregs[5]); err |= __put_user(sw->d6, &gregs[6]); err |= __put_user(sw->d7, &gregs[7]); err |= __put_user(regs->a0, &gregs[8]); err |= __put_user(regs->a1, &gregs[9]); err |= __put_user(regs->a2, &gregs[10]); err |= __put_user(sw->a3, &gregs[11]); err |= __put_user(sw->a4, &gregs[12]); err |= __put_user(sw->a5, &gregs[13]); err |= __put_user(sw->a6, &gregs[14]); err |= __put_user(rdusp(), &gregs[15]); err |= __put_user(regs->pc, &gregs[16]); err |= __put_user(regs->sr, &gregs[17]); #ifdef CONFIG_FPU err |= rt_save_fpu_state(uc, regs); #endif return err; } static inline void push_cache (unsigned long vaddr) { } static inline void * get_sigframe(struct k_sigaction *ka, struct pt_regs *regs, size_t frame_size) { unsigned long usp; /* Default to using normal stack. */ usp = rdusp(); /* This is the X/Open sanctioned signal stack switching. */ if (ka->sa.sa_flags & SA_ONSTACK) { if (!on_sig_stack(usp)) usp = current->sas_ss_sp + current->sas_ss_size; } return (void *)((usp - frame_size) & -8UL); } static void setup_frame (int sig, struct k_sigaction *ka, sigset_t *set, struct pt_regs *regs) { struct sigframe *frame; struct sigcontext context; int err = 0; frame = get_sigframe(ka, regs, sizeof(*frame)); err |= __put_user((current_thread_info()->exec_domain && current_thread_info()->exec_domain->signal_invmap && sig < 32 ? current_thread_info()->exec_domain->signal_invmap[sig] : sig), &frame->sig); err |= __put_user(regs->vector, &frame->code); err |= __put_user(&frame->sc, &frame->psc); if (_NSIG_WORDS > 1) err |= copy_to_user(frame->extramask, &set->sig[1], sizeof(frame->extramask)); setup_sigcontext(&context, regs, set->sig[0]); err |= copy_to_user (&frame->sc, &context, sizeof(context)); /* Set up to return from userspace. */ err |= __put_user(frame->retcode, &frame->pretcode); /* moveq #,d0; trap #0 */ err |= __put_user(0x70004e40 + (__NR_sigreturn << 16), (long *)(frame->retcode)); if (err) goto give_sigsegv; push_cache ((unsigned long) &frame->retcode); /* Set up registers for signal handler */ wrusp ((unsigned long) frame); regs->pc = (unsigned long) ka->sa.sa_handler; ((struct switch_stack *)regs - 1)->a5 = current->mm->start_data; regs->format = 0x4; /*set format byte to make stack appear modulo 4 which it will be when doing the rte */ adjust_stack: /* Prepare to skip over the extra stuff in the exception frame. */ if (regs->stkadj) { struct pt_regs *tregs = (struct pt_regs *)((ulong)regs + regs->stkadj); #if DEBUG printk(KERN_DEBUG "Performing stackadjust=%04x\n", regs->stkadj); #endif /* This must be copied with decreasing addresses to handle overlaps. */ tregs->vector = 0; tregs->format = 0; tregs->pc = regs->pc; tregs->sr = regs->sr; } return; give_sigsegv: force_sigsegv(sig, current); goto adjust_stack; } static void setup_rt_frame (int sig, struct k_sigaction *ka, siginfo_t *info, sigset_t *set, struct pt_regs *regs) { struct rt_sigframe *frame; int err = 0; frame = get_sigframe(ka, regs, sizeof(*frame)); err |= __put_user((current_thread_info()->exec_domain && current_thread_info()->exec_domain->signal_invmap && sig < 32 ? current_thread_info()->exec_domain->signal_invmap[sig] : sig), &frame->sig); err |= __put_user(&frame->info, &frame->pinfo); err |= __put_user(&frame->uc, &frame->puc); err |= copy_siginfo_to_user(&frame->info, info); /* Create the ucontext. */ err |= __put_user(0, &frame->uc.uc_flags); err |= __put_user(0, &frame->uc.uc_link); err |= __put_user((void *)current->sas_ss_sp, &frame->uc.uc_stack.ss_sp); err |= __put_user(sas_ss_flags(rdusp()), &frame->uc.uc_stack.ss_flags); err |= __put_user(current->sas_ss_size, &frame->uc.uc_stack.ss_size); err |= rt_setup_ucontext(&frame->uc, regs); err |= copy_to_user (&frame->uc.uc_sigmask, set, sizeof(*set)); /* Set up to return from userspace. */ err |= __put_user(frame->retcode, &frame->pretcode); /* moveq #,d0; notb d0; trap #0 */ err |= __put_user(0x70004600 + ((__NR_rt_sigreturn ^ 0xff) << 16), (long *)(frame->retcode + 0)); err |= __put_user(0x4e40, (short *)(frame->retcode + 4)); if (err) goto give_sigsegv; push_cache ((unsigned long) &frame->retcode); /* Set up registers for signal handler */ wrusp ((unsigned long) frame); regs->pc = (unsigned long) ka->sa.sa_handler; ((struct switch_stack *)regs - 1)->a5 = current->mm->start_data; regs->format = 0x4; /*set format byte to make stack appear modulo 4 which it will be when doing the rte */ adjust_stack: /* Prepare to skip over the extra stuff in the exception frame. */ if (regs->stkadj) { struct pt_regs *tregs = (struct pt_regs *)((ulong)regs + regs->stkadj); #if DEBUG printk(KERN_DEBUG "Performing stackadjust=%04x\n", regs->stkadj); #endif /* This must be copied with decreasing addresses to handle overlaps. */ tregs->vector = 0; tregs->format = 0; tregs->pc = regs->pc; tregs->sr = regs->sr; } return; give_sigsegv: force_sigsegv(sig, current); goto adjust_stack; } static inline void handle_restart(struct pt_regs *regs, struct k_sigaction *ka, int has_handler) { switch (regs->d0) { case -ERESTARTNOHAND: if (!has_handler) goto do_restart; regs->d0 = -EINTR; break; case -ERESTARTSYS: if (has_handler && !(ka->sa.sa_flags & SA_RESTART)) { regs->d0 = -EINTR; break; } /* fallthrough */ case -ERESTARTNOINTR: do_restart: regs->d0 = regs->orig_d0; regs->pc -= 2; break; } } /* * OK, we're invoking a handler */ static void handle_signal(int sig, struct k_sigaction *ka, siginfo_t *info, sigset_t *oldset, struct pt_regs *regs) { /* are we from a system call? */ if (regs->orig_d0 >= 0) /* If so, check system call restarting.. */ handle_restart(regs, ka, 1); /* set up the stack frame */ if (ka->sa.sa_flags & SA_SIGINFO) setup_rt_frame(sig, ka, info, oldset, regs); else setup_frame(sig, ka, oldset, regs); if (ka->sa.sa_flags & SA_ONESHOT) ka->sa.sa_handler = SIG_DFL; spin_lock_irq(¤t->sighand->siglock); sigorsets(¤t->blocked,¤t->blocked,&ka->sa.sa_mask); if (!(ka->sa.sa_flags & SA_NODEFER)) sigaddset(¤t->blocked,sig); recalc_sigpending(); spin_unlock_irq(¤t->sighand->siglock); } /* * Note that 'init' is a special process: it doesn't get signals it doesn't * want to handle. Thus you cannot kill init even with a SIGKILL even by * mistake. */ asmlinkage int do_signal(sigset_t *oldset, struct pt_regs *regs) { struct k_sigaction ka; siginfo_t info; int signr; /* * We want the common case to go fast, which * is why we may in certain cases get here from * kernel mode. Just return without doing anything * if so. */ if (!user_mode(regs)) return 1; if (!oldset) oldset = ¤t->blocked; signr = get_signal_to_deliver(&info, &ka, regs, NULL); if (signr > 0) { /* Whee! Actually deliver the signal. */ handle_signal(signr, &ka, &info, oldset, regs); return 1; } /* Did we come from a system call? */ if (regs->orig_d0 >= 0) { /* Restart the system call - no handlers present */ if (regs->d0 == -ERESTARTNOHAND || regs->d0 == -ERESTARTSYS || regs->d0 == -ERESTARTNOINTR) { regs->d0 = regs->orig_d0; regs->pc -= 2; } else if (regs->d0 == -ERESTART_RESTARTBLOCK) { regs->d0 = __NR_restart_syscall; regs->pc -= 2; } } return 0; }