/* $Id: signal.c,v 1.21 2000/03/11 14:06:21 gniibe Exp $ * * linux/arch/sh/kernel/signal.c * * Copyright (C) 1991, 1992 Linus Torvalds * * 1997-11-28 Modified for POSIX.1b signals by Richard Henderson * * SuperH version: Copyright (C) 1999, 2000 Niibe Yutaka & Kaz Kojima * */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #define DEBUG_SIG 0 #define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP))) asmlinkage int do_signal(struct pt_regs *regs, sigset_t *oldset); int copy_siginfo_to_user(siginfo_t *to, siginfo_t *from) { if (!access_ok (VERIFY_WRITE, to, sizeof(siginfo_t))) return -EFAULT; if (from->si_code < 0) return __copy_to_user(to, from, sizeof(siginfo_t)); else { int err; /* If you change siginfo_t structure, please be sure this code is fixed accordingly. It should never copy any pad contained in the structure to avoid security leaks, but must copy the generic 3 ints plus the relevant union member. */ err = __put_user(from->si_signo, &to->si_signo); err |= __put_user(from->si_errno, &to->si_errno); err |= __put_user((short)from->si_code, &to->si_code); /* First 32bits of unions are always present. */ err |= __put_user(from->si_pid, &to->si_pid); switch (from->si_code >> 16) { case __SI_FAULT >> 16: break; case __SI_CHLD >> 16: err |= __put_user(from->si_utime, &to->si_utime); err |= __put_user(from->si_stime, &to->si_stime); err |= __put_user(from->si_status, &to->si_status); default: err |= __put_user(from->si_uid, &to->si_uid); break; /* case __SI_RT: This is not generated by the kernel as of now. */ } return err; } } /* * Atomically swap in the new signal mask, and wait for a signal. */ asmlinkage int sys_sigsuspend(old_sigset_t mask, unsigned long r5, unsigned long r6, unsigned long r7, struct pt_regs regs) { sigset_t saveset; mask &= _BLOCKABLE; spin_lock_irq(¤t->sigmask_lock); saveset = current->blocked; siginitset(¤t->blocked, mask); recalc_sigpending(current); spin_unlock_irq(¤t->sigmask_lock); regs.regs[0] = -EINTR; while (1) { current->state = TASK_INTERRUPTIBLE; schedule(); if (do_signal(®s, &saveset)) return -EINTR; } } asmlinkage int sys_rt_sigsuspend(sigset_t *unewset, size_t sigsetsize, unsigned long r6, unsigned long r7, struct pt_regs regs) { 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->sigmask_lock); saveset = current->blocked; current->blocked = newset; recalc_sigpending(current); spin_unlock_irq(¤t->sigmask_lock); regs.regs[0] = -EINTR; while (1) { current->state = TASK_INTERRUPTIBLE; schedule(); if (do_signal(®s, &saveset)) 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 (verify_area(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 (verify_area(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, unsigned long r6, unsigned long r7, struct pt_regs regs) { return do_sigaltstack(uss, uoss, regs.regs[15]); } /* * Do a signal return; undo the signal stack. */ struct sigframe { struct sigcontext sc; unsigned long extramask[_NSIG_WORDS-1]; char retcode[4]; }; struct rt_sigframe { struct siginfo *pinfo; void *puc; struct siginfo info; struct ucontext uc; char retcode[4]; }; #if defined(__SH4__) static inline int restore_sigcontext_fpu(struct sigcontext *sc) { struct task_struct *tsk = current; tsk->used_math = 1; return __copy_from_user(&tsk->thread.fpu.hard, &sc->sc_fpregs[0], sizeof(long)*(16*2+2)); } static inline int save_sigcontext_fpu(struct sigcontext *sc) { struct task_struct *tsk = current; unsigned long flags; int val; if (!tsk->used_math) { val = 0; __copy_to_user(&sc->sc_ownedfp, &val, sizeof(int)); return 0; } val = 1; __copy_to_user(&sc->sc_ownedfp, &val, sizeof(int)); /* This will cause a "finit" to be triggered by the next attempted FPU operation by the 'current' process. */ tsk->used_math = 0; save_and_cli(flags); unlazy_fpu(tsk); restore_flags(flags); return __copy_to_user(&sc->sc_fpregs[0], &tsk->thread.fpu.hard, sizeof(long)*(16*2+2)); } #endif static int restore_sigcontext(struct pt_regs *regs, struct sigcontext *sc, int *r0_p) { unsigned int err = 0; #define COPY(x) err |= __get_user(regs->x, &sc->sc_##x) COPY(regs[1]); COPY(regs[2]); COPY(regs[3]); COPY(regs[4]); COPY(regs[5]); COPY(regs[6]); COPY(regs[7]); COPY(regs[8]); COPY(regs[9]); COPY(regs[10]); COPY(regs[11]); COPY(regs[12]); COPY(regs[13]); COPY(regs[14]); COPY(regs[15]); COPY(gbr); COPY(mach); COPY(macl); COPY(pr); COPY(sr); COPY(pc); #undef COPY #if defined(__SH4__) { int owned_fp; struct task_struct *tsk = current; regs->sr |= SR_FD; /* Release FPU */ clear_fpu(tsk); current->used_math = 0; __get_user (owned_fp, &sc->sc_ownedfp); if (owned_fp) err |= restore_sigcontext_fpu(sc); } #endif regs->syscall_nr = -1; /* disable syscall checks */ err |= __get_user(*r0_p, &sc->sc_regs[0]); return err; } asmlinkage int sys_sigreturn(unsigned long r4, unsigned long r5, unsigned long r6, unsigned long r7, struct pt_regs regs) { struct sigframe *frame = (struct sigframe *)regs.regs[15]; sigset_t set; int r0; if (verify_area(VERIFY_READ, frame, sizeof(*frame))) goto badframe; if (__get_user(set.sig[0], &frame->sc.oldmask) || (_NSIG_WORDS > 1 && __copy_from_user(&set.sig[1], &frame->extramask, sizeof(frame->extramask)))) goto badframe; sigdelsetmask(&set, ~_BLOCKABLE); spin_lock_irq(¤t->sigmask_lock); current->blocked = set; recalc_sigpending(current); spin_unlock_irq(¤t->sigmask_lock); if (restore_sigcontext(®s, &frame->sc, &r0)) goto badframe; return r0; badframe: force_sig(SIGSEGV, current); return 0; } asmlinkage int sys_rt_sigreturn(unsigned long r4, unsigned long r5, unsigned long r6, unsigned long r7, struct pt_regs regs) { struct rt_sigframe *frame = (struct rt_sigframe *)regs.regs[15]; sigset_t set; stack_t st; int r0; if (verify_area(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->sigmask_lock); current->blocked = set; recalc_sigpending(current); spin_unlock_irq(¤t->sigmask_lock); if (restore_sigcontext(®s, &frame->uc.uc_mcontext, &r0)) goto badframe; if (__copy_from_user(&st, &frame->uc.uc_stack, sizeof(st))) goto badframe; /* It is more difficult to avoid calling this function than to call it and ignore errors. */ do_sigaltstack(&st, NULL, regs.regs[15]); return r0; badframe: force_sig(SIGSEGV, current); return 0; } /* * Set up a signal frame. */ static int setup_sigcontext(struct sigcontext *sc, struct pt_regs *regs, unsigned long mask) { int err = 0; #define COPY(x) err |= __put_user(regs->x, &sc->sc_##x) COPY(regs[0]); COPY(regs[1]); COPY(regs[2]); COPY(regs[3]); COPY(regs[4]); COPY(regs[5]); COPY(regs[6]); COPY(regs[7]); COPY(regs[8]); COPY(regs[9]); COPY(regs[10]); COPY(regs[11]); COPY(regs[12]); COPY(regs[13]); COPY(regs[14]); COPY(regs[15]); COPY(gbr); COPY(mach); COPY(macl); COPY(pr); COPY(sr); COPY(pc); #undef COPY #if defined(__SH4__) err |= save_sigcontext_fpu(sc); #endif /* non-iBCS2 extensions.. */ err |= __put_user(mask, &sc->oldmask); return err; } /* * Determine which stack to use.. */ static inline void * get_sigframe(struct k_sigaction *ka, unsigned long sp, size_t frame_size) { if ((ka->sa.sa_flags & SA_ONSTACK) != 0 && ! on_sig_stack(sp)) sp = current->sas_ss_sp + current->sas_ss_size; return (void *)((sp - frame_size) & -8ul); } static void setup_frame(int sig, struct k_sigaction *ka, sigset_t *set, struct pt_regs *regs) { struct sigframe *frame; int err = 0; int signal; frame = get_sigframe(ka, regs->regs[15], sizeof(*frame)); if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame))) goto give_sigsegv; signal = current->exec_domain && current->exec_domain->signal_invmap && sig < 32 ? current->exec_domain->signal_invmap[sig] : sig; err |= setup_sigcontext(&frame->sc, regs, set->sig[0]); if (_NSIG_WORDS > 1) { err |= __copy_to_user(frame->extramask, &set->sig[1], sizeof(frame->extramask)); } /* Set up to return from userspace. If provided, use a stub already in userspace. */ if (ka->sa.sa_flags & SA_RESTORER) { regs->pr = (unsigned long) ka->sa.sa_restorer; } else { /* This is : mov #__NR_sigreturn,r3 ; trapa #0x10 */ #ifdef __LITTLE_ENDIAN__ unsigned long code = 0xc310e300 | (__NR_sigreturn); #else unsigned long code = 0xe300c310 | (__NR_sigreturn << 16); #endif regs->pr = (unsigned long) frame->retcode; err |= __put_user(code, (long *)(frame->retcode+0)); } if (err) goto give_sigsegv; /* Set up registers for signal handler */ regs->regs[15] = (unsigned long) frame; regs->regs[4] = signal; /* Arg for signal handler */ regs->pc = (unsigned long) ka->sa.sa_handler; set_fs(USER_DS); #if DEBUG_SIG printk("SIG deliver (%s:%d): sp=%p pc=%08lx pr=%08lx\n", current->comm, current->pid, frame, regs->pc, regs->pr); #endif flush_cache_sigtramp(regs->pr); return; give_sigsegv: if (sig == SIGSEGV) ka->sa.sa_handler = SIG_DFL; force_sig(SIGSEGV, current); } 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; int signal; frame = get_sigframe(ka, regs->regs[15], sizeof(*frame)); if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame))) goto give_sigsegv; signal = current->exec_domain && current->exec_domain->signal_invmap && sig < 32 ? current->exec_domain->signal_invmap[sig] : 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(regs->regs[15]), &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)); /* Set up to return from userspace. If provided, use a stub already in userspace. */ if (ka->sa.sa_flags & SA_RESTORER) { regs->pr = (unsigned long) ka->sa.sa_restorer; } else { /* This is : mov #__NR_rt_sigreturn,r3 ; trapa #0x10 */ #ifdef __LITTLE_ENDIAN__ unsigned long code = 0xc310e300 | (__NR_rt_sigreturn); #else unsigned long code = 0xe300c310 | (__NR_rt_sigreturn << 16); #endif regs->pr = (unsigned long) frame->retcode; err |= __put_user(code, (long *)(frame->retcode+0)); } if (err) goto give_sigsegv; /* Set up registers for signal handler */ regs->regs[15] = (unsigned long) frame; regs->regs[4] = signal; /* Arg for signal handler */ regs->pc = (unsigned long) ka->sa.sa_handler; set_fs(USER_DS); #if DEBUG_SIG printk("SIG deliver (%s:%d): sp=%p pc=%08lx pr=%08lx\n", current->comm, current->pid, frame, regs->pc, regs->pr); #endif flush_cache_sigtramp(regs->pr); return; give_sigsegv: if (sig == SIGSEGV) ka->sa.sa_handler = SIG_DFL; force_sig(SIGSEGV, current); } /* * OK, we're invoking a handler */ static void handle_signal(unsigned long sig, struct k_sigaction *ka, siginfo_t *info, sigset_t *oldset, struct pt_regs * regs) { /* Are we from a system call? */ if (regs->syscall_nr >= 0) { /* If so, check system call restarting.. */ switch (regs->regs[0]) { case -ERESTARTNOHAND: regs->regs[0] = -EINTR; break; case -ERESTARTSYS: if (!(ka->sa.sa_flags & SA_RESTART)) { regs->regs[0] = -EINTR; break; } /* fallthrough */ case -ERESTARTNOINTR: regs->regs[0] = regs->syscall_nr; regs->pc -= 2; } } /* 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; if (!(ka->sa.sa_flags & SA_NODEFER)) { spin_lock_irq(¤t->sigmask_lock); sigorsets(¤t->blocked,¤t->blocked,&ka->sa.sa_mask); sigaddset(¤t->blocked,sig); recalc_sigpending(current); spin_unlock_irq(¤t->sigmask_lock); } } /* * 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. * * Note that we go through the signals twice: once to check the signals that * the kernel can handle, and then we build all the user-level signal handling * stack-frames in one go after that. */ int do_signal(struct pt_regs *regs, sigset_t *oldset) { siginfo_t info; 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 (!user_mode(regs)) return 1; if (!oldset) oldset = ¤t->blocked; for (;;) { unsigned long signr; spin_lock_irq(¤t->sigmask_lock); signr = dequeue_signal(¤t->blocked, &info); spin_unlock_irq(¤t->sigmask_lock); if (!signr) break; if ((current->ptrace & PT_PTRACED) && signr != SIGKILL) { /* Let the debugger run. */ current->exit_code = signr; current->state = TASK_STOPPED; notify_parent(current, SIGCHLD); schedule(); /* We're back. Did the debugger cancel the sig? */ if (!(signr = current->exit_code)) continue; current->exit_code = 0; /* The debugger continued. Ignore SIGSTOP. */ if (signr == SIGSTOP) continue; /* Update the siginfo structure. Is this good? */ if (signr != info.si_signo) { info.si_signo = signr; info.si_errno = 0; info.si_code = SI_USER; info.si_pid = current->p_pptr->pid; info.si_uid = current->p_pptr->uid; } /* If the (new) signal is now blocked, requeue it. */ if (sigismember(¤t->blocked, signr)) { send_sig_info(signr, &info, current); continue; } } ka = ¤t->sig->action[signr-1]; if (ka->sa.sa_handler == SIG_IGN) { if (signr != SIGCHLD) continue; /* Check for SIGCHLD: it's special. */ while (sys_wait4(-1, NULL, WNOHANG, NULL) > 0) /* nothing */; continue; } if (ka->sa.sa_handler == SIG_DFL) { int exit_code = signr; /* Init gets no signals it doesn't want. */ if (current->pid == 1) continue; switch (signr) { case SIGCONT: case SIGCHLD: case SIGWINCH: continue; case SIGTSTP: case SIGTTIN: case SIGTTOU: if (is_orphaned_pgrp(current->pgrp)) continue; /* FALLTHRU */ case SIGSTOP: current->state = TASK_STOPPED; current->exit_code = signr; if (!(current->p_pptr->sig->action[SIGCHLD-1].sa.sa_flags & SA_NOCLDSTOP)) notify_parent(current, SIGCHLD); schedule(); continue; case SIGQUIT: case SIGILL: case SIGTRAP: case SIGABRT: case SIGFPE: case SIGSEGV: case SIGBUS: case SIGSYS: case SIGXCPU: case SIGXFSZ: if (do_coredump(signr, regs)) exit_code |= 0x80; /* FALLTHRU */ default: sigaddset(¤t->pending.signal, signr); recalc_sigpending(current); current->flags |= PF_SIGNALED; do_exit(exit_code); /* NOTREACHED */ } } /* Whee! Actually deliver the signal. */ handle_signal(signr, ka, &info, oldset, regs); return 1; } /* Did we come from a system call? */ if (regs->syscall_nr >= 0) { /* Restart the system call - no handlers present */ if (regs->regs[0] == -ERESTARTNOHAND || regs->regs[0] == -ERESTARTSYS || regs->regs[0] == -ERESTARTNOINTR) { regs->regs[0] = regs->syscall_nr; regs->pc -= 2; } } return 0; }