/* * linux/arch/h8300/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. */ /* * uClinux H8/300 support by Yoshinori Sato * and David McCullough * * Based on * Linux/m68k by Hamish Macdonald */ /* * ++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 #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP))) /* * Atomically swap in the new signal mask, and wait for a signal. */ asmlinkage int sys_sigsuspend(int unused1, int unused2, old_sigset_t mask) { sigset_t blocked; siginitset(&blocked, mask); return sigsuspend(&blocked); } 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) || __get_user(new_ka.sa.sa_flags, &act->sa_flags) || __get_user(mask, &act->sa_mask)) return -EFAULT; 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) || __put_user(old_ka.sa.sa_flags, &oact->sa_flags) || __put_user(old_ka.sa.sa_mask.sig[0], &oact->sa_mask)) return -EFAULT; } 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 { long dummy_er0; long dummy_vector; #if defined(CONFIG_CPU_H8S) short dummy_exr; #endif long dummy_pc; char *pretcode; unsigned char retcode[8]; unsigned long extramask[_NSIG_WORDS-1]; struct sigcontext sc; int sig; } __attribute__((aligned(2),packed)); struct rt_sigframe { long dummy_er0; long dummy_vector; #if defined(CONFIG_CPU_H8S) short dummy_exr; #endif long dummy_pc; char *pretcode; struct siginfo *pinfo; void *puc; unsigned char retcode[8]; struct siginfo info; struct ucontext uc; int sig; } __attribute__((aligned(2),packed)); static inline int restore_sigcontext(struct pt_regs *regs, struct sigcontext *usc, int *pd0) { int err = 0; unsigned int ccr; unsigned int usp; unsigned int er0; /* Always make any pending restarted system calls return -EINTR */ current_thread_info()->restart_block.fn = do_no_restart_syscall; #define COPY(r) err |= __get_user(regs->r, &usc->sc_##r) /* restore passed registers */ COPY(er1); COPY(er2); COPY(er3); COPY(er5); COPY(pc); ccr = regs->ccr & 0x10; COPY(ccr); #undef COPY regs->ccr &= 0xef; regs->ccr |= ccr; regs->orig_er0 = -1; /* disable syscall checks */ err |= __get_user(usp, &usc->sc_usp); wrusp(usp); err |= __get_user(er0, &usc->sc_er0); *pd0 = er0; return err; } asmlinkage int do_sigreturn(unsigned long __unused,...) { struct pt_regs *regs = (struct pt_regs *) (&__unused - 1); unsigned long usp = rdusp(); struct sigframe *frame = (struct sigframe *)(usp - 4); sigset_t set; int er0; 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); set_current_blocked(&set); if (restore_sigcontext(regs, &frame->sc, &er0)) goto badframe; return er0; badframe: force_sig(SIGSEGV, current); return 0; } asmlinkage int do_rt_sigreturn(unsigned long __unused,...) { struct pt_regs *regs = (struct pt_regs *) &__unused; unsigned long usp = rdusp(); struct rt_sigframe *frame = (struct rt_sigframe *)(usp - 4); sigset_t set; int er0; 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); set_current_blocked(&set); if (restore_sigcontext(regs, &frame->uc.uc_mcontext, &er0)) goto badframe; if (do_sigaltstack(&frame->uc.uc_stack, NULL, usp) == -EFAULT) goto badframe; return er0; badframe: force_sig(SIGSEGV, current); return 0; } static int setup_sigcontext(struct sigcontext __user *sc, struct pt_regs *regs, unsigned long mask) { int err = 0; err |= __put_user(regs->er0, &sc->sc_er0); err |= __put_user(regs->er1, &sc->sc_er1); err |= __put_user(regs->er2, &sc->sc_er2); err |= __put_user(regs->er3, &sc->sc_er3); err |= __put_user(regs->er4, &sc->sc_er4); err |= __put_user(regs->er5, &sc->sc_er5); err |= __put_user(regs->er6, &sc->sc_er6); err |= __put_user(rdusp(), &sc->sc_usp); err |= __put_user(regs->pc, &sc->sc_pc); err |= __put_user(regs->ccr, &sc->sc_ccr); err |= __put_user(mask, &sc->sc_mask); return err; } 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 (!sas_ss_flags(usp)) usp = current->sas_ss_sp + current->sas_ss_size; } return (void *)((usp - frame_size) & -8UL); } static int setup_frame (int sig, struct k_sigaction *ka, sigset_t *set, struct pt_regs *regs) { struct sigframe *frame; int err = 0; int usig; unsigned char *ret; frame = get_sigframe(ka, regs, sizeof(*frame)); if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame))) goto give_sigsegv; usig = current_thread_info()->exec_domain && current_thread_info()->exec_domain->signal_invmap && sig < 32 ? current_thread_info()->exec_domain->signal_invmap[sig] : sig; err |= __put_user(usig, &frame->sig); if (err) goto give_sigsegv; err |= setup_sigcontext(&frame->sc, regs, set->sig[0]); if (err) goto give_sigsegv; if (_NSIG_WORDS > 1) { err |= copy_to_user(frame->extramask, &set->sig[1], sizeof(frame->extramask)); if (err) goto give_sigsegv; } ret = frame->retcode; if (ka->sa.sa_flags & SA_RESTORER) ret = (unsigned char *)(ka->sa.sa_restorer); else { /* sub.l er0,er0; mov.b #__NR_sigreturn,r0l; trapa #0 */ err |= __put_user(0x1a80f800 + (__NR_sigreturn & 0xff), (unsigned long *)(frame->retcode + 0)); err |= __put_user(0x5700, (unsigned short *)(frame->retcode + 4)); } /* Set up to return from userspace. */ err |= __put_user(ret, &frame->pretcode); if (err) goto give_sigsegv; /* Set up registers for signal handler */ wrusp ((unsigned long) frame); regs->pc = (unsigned long) ka->sa.sa_handler; regs->er0 = (current_thread_info()->exec_domain && current_thread_info()->exec_domain->signal_invmap && sig < 32 ? current_thread_info()->exec_domain->signal_invmap[sig] : sig); regs->er1 = (unsigned long)&(frame->sc); regs->er5 = current->mm->start_data; /* GOT base */ return 0; give_sigsegv: force_sigsegv(sig, current); return -EFAULT; } static int 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; int usig; unsigned char *ret; frame = get_sigframe(ka, regs, sizeof(*frame)); if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame))) goto give_sigsegv; usig = current_thread_info()->exec_domain && current_thread_info()->exec_domain->signal_invmap && sig < 32 ? current_thread_info()->exec_domain->signal_invmap[sig] : sig; err |= __put_user(usig, &frame->sig); if (err) goto give_sigsegv; err |= __put_user(&frame->info, &frame->pinfo); err |= __put_user(&frame->uc, &frame->puc); err |= copy_siginfo_to_user(&frame->info, info); if (err) goto give_sigsegv; /* 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 |= setup_sigcontext(&frame->uc.uc_mcontext, regs, set->sig[0]); err |= copy_to_user (&frame->uc.uc_sigmask, set, sizeof(*set)); if (err) goto give_sigsegv; /* Set up to return from userspace. */ ret = frame->retcode; if (ka->sa.sa_flags & SA_RESTORER) ret = (unsigned char *)(ka->sa.sa_restorer); else { /* sub.l er0,er0; mov.b #__NR_sigreturn,r0l; trapa #0 */ err |= __put_user(0x1a80f800 + (__NR_sigreturn & 0xff), (unsigned long *)(frame->retcode + 0)); err |= __put_user(0x5700, (unsigned short *)(frame->retcode + 4)); } err |= __put_user(ret, &frame->pretcode); if (err) goto give_sigsegv; /* Set up registers for signal handler */ wrusp ((unsigned long) frame); regs->pc = (unsigned long) ka->sa.sa_handler; regs->er0 = (current_thread_info()->exec_domain && current_thread_info()->exec_domain->signal_invmap && sig < 32 ? current_thread_info()->exec_domain->signal_invmap[sig] : sig); regs->er1 = (unsigned long)&(frame->info); regs->er2 = (unsigned long)&frame->uc; regs->er5 = current->mm->start_data; /* GOT base */ return 0; give_sigsegv: force_sigsegv(sig, current); return -EFAULT; } /* * OK, we're invoking a handler */ static void handle_signal(unsigned long sig, siginfo_t *info, struct k_sigaction *ka, struct pt_regs * regs) { sigset_t *oldset = sigmask_to_save(); int ret; /* are we from a system call? */ if (regs->orig_er0 >= 0) { switch (regs->er0) { case -ERESTART_RESTARTBLOCK: case -ERESTARTNOHAND: regs->er0 = -EINTR; break; case -ERESTARTSYS: if (!(ka->sa.sa_flags & SA_RESTART)) { regs->er0 = -EINTR; break; } /* fallthrough */ case -ERESTARTNOINTR: regs->er0 = regs->orig_er0; regs->pc -= 2; } } /* set up the stack frame */ if (ka->sa.sa_flags & SA_SIGINFO) ret = setup_rt_frame(sig, ka, info, oldset, regs); else ret = setup_frame(sig, ka, oldset, regs); if (!ret) block_sigmask(ka, sig); } /* * 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. */ statis void do_signal(struct pt_regs *regs) { siginfo_t info; int signr; struct k_sigaction ka; /* * 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 ((regs->ccr & 0x10)) return; current->thread.esp0 = (unsigned long) regs; signr = get_signal_to_deliver(&info, &ka, regs, NULL); if (signr > 0) { /* Whee! Actually deliver the signal. */ handle_signal(signr, &info, &ka, regs); return; } /* Did we come from a system call? */ if (regs->orig_er0 >= 0) { /* Restart the system call - no handlers present */ if (regs->er0 == -ERESTARTNOHAND || regs->er0 == -ERESTARTSYS || regs->er0 == -ERESTARTNOINTR) { regs->er0 = regs->orig_er0; regs->pc -= 2; } if (regs->er0 == -ERESTART_RESTARTBLOCK){ regs->er0 = __NR_restart_syscall; regs->pc -= 2; } } /* If there's no signal to deliver, we just restore the saved mask. */ restore_saved_sigmask(); } asmlinkage void do_notify_resume(struct pt_regs *regs, u32 thread_info_flags) { if (thread_info_flags & _TIF_SIGPENDING) do_signal(regs); if (thread_info_flags & _TIF_NOTIFY_RESUME) { clear_thread_flag(TIF_NOTIFY_RESUME); tracehook_notify_resume(regs); } }