586 lines
15 KiB
C
586 lines
15 KiB
C
/* signal.c: FRV specific bits of signal handling
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*
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* Copyright (C) 2003-5 Red Hat, Inc. All Rights Reserved.
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* Written by David Howells (dhowells@redhat.com)
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* - Derived from arch/m68k/kernel/signal.c
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version
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* 2 of the License, or (at your option) any later version.
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*/
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#include <linux/sched.h>
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#include <linux/mm.h>
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#include <linux/smp.h>
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#include <linux/smp_lock.h>
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#include <linux/kernel.h>
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#include <linux/signal.h>
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#include <linux/errno.h>
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#include <linux/wait.h>
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#include <linux/ptrace.h>
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#include <linux/unistd.h>
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#include <linux/personality.h>
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#include <linux/suspend.h>
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#include <asm/ucontext.h>
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#include <asm/uaccess.h>
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#include <asm/cacheflush.h>
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#define DEBUG_SIG 0
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#define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP)))
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struct fdpic_func_descriptor {
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unsigned long text;
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unsigned long GOT;
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};
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asmlinkage int do_signal(struct pt_regs *regs, sigset_t *oldset);
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/*
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* Atomically swap in the new signal mask, and wait for a signal.
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*/
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asmlinkage int sys_sigsuspend(int history0, int history1, old_sigset_t mask)
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{
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sigset_t saveset;
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mask &= _BLOCKABLE;
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spin_lock_irq(¤t->sighand->siglock);
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saveset = current->blocked;
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siginitset(¤t->blocked, mask);
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recalc_sigpending();
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spin_unlock_irq(¤t->sighand->siglock);
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__frame->gr8 = -EINTR;
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while (1) {
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current->state = TASK_INTERRUPTIBLE;
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schedule();
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if (do_signal(__frame, &saveset))
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/* return the signal number as the return value of this function
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* - this is an utterly evil hack. syscalls should not invoke do_signal()
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* as entry.S sets regs->gr8 to the return value of the system call
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* - we can't just use sigpending() as we'd have to discard SIG_IGN signals
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* and call waitpid() if SIGCHLD needed discarding
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* - this only works on the i386 because it passes arguments to the signal
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* handler on the stack, and the return value in EAX is effectively
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* discarded
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*/
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return __frame->gr8;
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}
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}
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asmlinkage int sys_rt_sigsuspend(sigset_t __user *unewset, size_t sigsetsize)
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{
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sigset_t saveset, newset;
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/* XXX: Don't preclude handling different sized sigset_t's. */
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if (sigsetsize != sizeof(sigset_t))
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return -EINVAL;
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if (copy_from_user(&newset, unewset, sizeof(newset)))
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return -EFAULT;
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sigdelsetmask(&newset, ~_BLOCKABLE);
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spin_lock_irq(¤t->sighand->siglock);
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saveset = current->blocked;
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current->blocked = newset;
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recalc_sigpending();
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spin_unlock_irq(¤t->sighand->siglock);
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__frame->gr8 = -EINTR;
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while (1) {
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current->state = TASK_INTERRUPTIBLE;
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schedule();
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if (do_signal(__frame, &saveset))
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/* return the signal number as the return value of this function
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* - this is an utterly evil hack. syscalls should not invoke do_signal()
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* as entry.S sets regs->gr8 to the return value of the system call
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* - we can't just use sigpending() as we'd have to discard SIG_IGN signals
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* and call waitpid() if SIGCHLD needed discarding
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* - this only works on the i386 because it passes arguments to the signal
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* handler on the stack, and the return value in EAX is effectively
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* discarded
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*/
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return __frame->gr8;
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}
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}
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asmlinkage int sys_sigaction(int sig,
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const struct old_sigaction __user *act,
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struct old_sigaction __user *oact)
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{
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struct k_sigaction new_ka, old_ka;
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int ret;
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if (act) {
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old_sigset_t mask;
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if (!access_ok(VERIFY_READ, act, sizeof(*act)) ||
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__get_user(new_ka.sa.sa_handler, &act->sa_handler) ||
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__get_user(new_ka.sa.sa_restorer, &act->sa_restorer))
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return -EFAULT;
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__get_user(new_ka.sa.sa_flags, &act->sa_flags);
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__get_user(mask, &act->sa_mask);
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siginitset(&new_ka.sa.sa_mask, mask);
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}
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ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL);
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if (!ret && oact) {
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if (!access_ok(VERIFY_WRITE, oact, sizeof(*oact)) ||
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__put_user(old_ka.sa.sa_handler, &oact->sa_handler) ||
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__put_user(old_ka.sa.sa_restorer, &oact->sa_restorer))
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return -EFAULT;
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__put_user(old_ka.sa.sa_flags, &oact->sa_flags);
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__put_user(old_ka.sa.sa_mask.sig[0], &oact->sa_mask);
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}
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return ret;
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}
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asmlinkage
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int sys_sigaltstack(const stack_t __user *uss, stack_t __user *uoss)
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{
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return do_sigaltstack(uss, uoss, __frame->sp);
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}
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/*
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* Do a signal return; undo the signal stack.
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*/
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struct sigframe
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{
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void (*pretcode)(void);
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int sig;
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struct sigcontext sc;
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unsigned long extramask[_NSIG_WORDS-1];
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uint32_t retcode[2];
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};
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struct rt_sigframe
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{
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void (*pretcode)(void);
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int sig;
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struct siginfo *pinfo;
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void *puc;
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struct siginfo info;
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struct ucontext uc;
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uint32_t retcode[2];
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};
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static int restore_sigcontext(struct sigcontext __user *sc, int *_gr8)
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{
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struct user_context *user = current->thread.user;
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unsigned long tbr, psr;
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tbr = user->i.tbr;
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psr = user->i.psr;
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if (copy_from_user(user, &sc->sc_context, sizeof(sc->sc_context)))
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goto badframe;
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user->i.tbr = tbr;
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user->i.psr = psr;
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restore_user_regs(user);
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user->i.syscallno = -1; /* disable syscall checks */
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*_gr8 = user->i.gr[8];
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return 0;
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badframe:
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return 1;
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}
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asmlinkage int sys_sigreturn(void)
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{
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struct sigframe __user *frame = (struct sigframe __user *) __frame->sp;
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sigset_t set;
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int gr8;
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if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
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goto badframe;
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if (__get_user(set.sig[0], &frame->sc.sc_oldmask))
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goto badframe;
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if (_NSIG_WORDS > 1 &&
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__copy_from_user(&set.sig[1], &frame->extramask, sizeof(frame->extramask)))
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goto badframe;
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sigdelsetmask(&set, ~_BLOCKABLE);
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spin_lock_irq(¤t->sighand->siglock);
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current->blocked = set;
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recalc_sigpending();
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spin_unlock_irq(¤t->sighand->siglock);
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if (restore_sigcontext(&frame->sc, &gr8))
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goto badframe;
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return gr8;
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badframe:
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force_sig(SIGSEGV, current);
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return 0;
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}
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asmlinkage int sys_rt_sigreturn(void)
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{
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struct rt_sigframe __user *frame = (struct rt_sigframe __user *) __frame->sp;
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sigset_t set;
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int gr8;
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if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
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goto badframe;
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if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set)))
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goto badframe;
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sigdelsetmask(&set, ~_BLOCKABLE);
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spin_lock_irq(¤t->sighand->siglock);
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current->blocked = set;
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recalc_sigpending();
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spin_unlock_irq(¤t->sighand->siglock);
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if (restore_sigcontext(&frame->uc.uc_mcontext, &gr8))
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goto badframe;
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if (do_sigaltstack(&frame->uc.uc_stack, NULL, __frame->sp) == -EFAULT)
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goto badframe;
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return gr8;
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badframe:
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force_sig(SIGSEGV, current);
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return 0;
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}
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/*
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* Set up a signal frame
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*/
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static int setup_sigcontext(struct sigcontext __user *sc, unsigned long mask)
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{
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save_user_regs(current->thread.user);
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if (copy_to_user(&sc->sc_context, current->thread.user, sizeof(sc->sc_context)) != 0)
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goto badframe;
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/* non-iBCS2 extensions.. */
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if (__put_user(mask, &sc->sc_oldmask) < 0)
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goto badframe;
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return 0;
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badframe:
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return 1;
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}
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/*****************************************************************************/
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/*
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* Determine which stack to use..
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*/
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static inline void __user *get_sigframe(struct k_sigaction *ka,
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struct pt_regs *regs,
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size_t frame_size)
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{
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unsigned long sp;
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/* Default to using normal stack */
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sp = regs->sp;
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/* This is the X/Open sanctioned signal stack switching. */
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if (ka->sa.sa_flags & SA_ONSTACK) {
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if (! on_sig_stack(sp))
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sp = current->sas_ss_sp + current->sas_ss_size;
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}
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return (void __user *) ((sp - frame_size) & ~7UL);
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} /* end get_sigframe() */
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/*****************************************************************************/
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/*
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*
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*/
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static void setup_frame(int sig, struct k_sigaction *ka, sigset_t *set, struct pt_regs * regs)
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{
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struct sigframe __user *frame;
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int rsig;
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frame = get_sigframe(ka, regs, sizeof(*frame));
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if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
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goto give_sigsegv;
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rsig = sig;
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if (sig < 32 &&
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__current_thread_info->exec_domain &&
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__current_thread_info->exec_domain->signal_invmap)
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rsig = __current_thread_info->exec_domain->signal_invmap[sig];
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if (__put_user(rsig, &frame->sig) < 0)
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goto give_sigsegv;
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if (setup_sigcontext(&frame->sc, set->sig[0]))
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goto give_sigsegv;
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if (_NSIG_WORDS > 1) {
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if (__copy_to_user(frame->extramask, &set->sig[1],
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sizeof(frame->extramask)))
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goto give_sigsegv;
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}
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/* Set up to return from userspace. If provided, use a stub
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* already in userspace. */
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if (ka->sa.sa_flags & SA_RESTORER) {
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if (__put_user(ka->sa.sa_restorer, &frame->pretcode) < 0)
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goto give_sigsegv;
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}
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else {
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/* Set up the following code on the stack:
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* setlos #__NR_sigreturn,gr7
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* tira gr0,0
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*/
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if (__put_user((void (*)(void))frame->retcode, &frame->pretcode) ||
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__put_user(0x8efc0000|__NR_sigreturn, &frame->retcode[0]) ||
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__put_user(0xc0700000, &frame->retcode[1]))
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goto give_sigsegv;
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flush_icache_range((unsigned long) frame->retcode,
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(unsigned long) (frame->retcode + 2));
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}
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/* set up registers for signal handler */
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regs->sp = (unsigned long) frame;
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regs->lr = (unsigned long) &frame->retcode;
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regs->gr8 = sig;
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if (get_personality & FDPIC_FUNCPTRS) {
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struct fdpic_func_descriptor __user *funcptr =
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(struct fdpic_func_descriptor *) ka->sa.sa_handler;
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__get_user(regs->pc, &funcptr->text);
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__get_user(regs->gr15, &funcptr->GOT);
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} else {
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regs->pc = (unsigned long) ka->sa.sa_handler;
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regs->gr15 = 0;
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}
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set_fs(USER_DS);
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#if DEBUG_SIG
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printk("SIG deliver %d (%s:%d): sp=%p pc=%lx ra=%p\n",
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sig, current->comm, current->pid, frame, regs->pc, frame->pretcode);
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#endif
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return;
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give_sigsegv:
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if (sig == SIGSEGV)
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ka->sa.sa_handler = SIG_DFL;
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force_sig(SIGSEGV, current);
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} /* end setup_frame() */
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/*****************************************************************************/
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/*
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*
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*/
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static void setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
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sigset_t *set, struct pt_regs * regs)
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{
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struct rt_sigframe __user *frame;
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int rsig;
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frame = get_sigframe(ka, regs, sizeof(*frame));
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if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
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goto give_sigsegv;
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rsig = sig;
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if (sig < 32 &&
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__current_thread_info->exec_domain &&
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__current_thread_info->exec_domain->signal_invmap)
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rsig = __current_thread_info->exec_domain->signal_invmap[sig];
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if (__put_user(rsig, &frame->sig) ||
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__put_user(&frame->info, &frame->pinfo) ||
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__put_user(&frame->uc, &frame->puc))
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goto give_sigsegv;
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if (copy_siginfo_to_user(&frame->info, info))
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goto give_sigsegv;
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/* Create the ucontext. */
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if (__put_user(0, &frame->uc.uc_flags) ||
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__put_user(0, &frame->uc.uc_link) ||
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__put_user((void*)current->sas_ss_sp, &frame->uc.uc_stack.ss_sp) ||
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__put_user(sas_ss_flags(regs->sp), &frame->uc.uc_stack.ss_flags) ||
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__put_user(current->sas_ss_size, &frame->uc.uc_stack.ss_size))
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goto give_sigsegv;
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if (setup_sigcontext(&frame->uc.uc_mcontext, set->sig[0]))
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goto give_sigsegv;
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if (__copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set)))
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goto give_sigsegv;
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/* Set up to return from userspace. If provided, use a stub
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* already in userspace. */
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if (ka->sa.sa_flags & SA_RESTORER) {
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if (__put_user(ka->sa.sa_restorer, &frame->pretcode))
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goto give_sigsegv;
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}
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else {
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/* Set up the following code on the stack:
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* setlos #__NR_sigreturn,gr7
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* tira gr0,0
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*/
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if (__put_user((void (*)(void))frame->retcode, &frame->pretcode) ||
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__put_user(0x8efc0000|__NR_rt_sigreturn, &frame->retcode[0]) ||
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__put_user(0xc0700000, &frame->retcode[1]))
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goto give_sigsegv;
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flush_icache_range((unsigned long) frame->retcode,
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(unsigned long) (frame->retcode + 2));
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}
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/* Set up registers for signal handler */
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regs->sp = (unsigned long) frame;
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regs->lr = (unsigned long) &frame->retcode;
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regs->gr8 = sig;
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regs->gr9 = (unsigned long) &frame->info;
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if (get_personality & FDPIC_FUNCPTRS) {
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struct fdpic_func_descriptor *funcptr =
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(struct fdpic_func_descriptor __user *) ka->sa.sa_handler;
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__get_user(regs->pc, &funcptr->text);
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__get_user(regs->gr15, &funcptr->GOT);
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} else {
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regs->pc = (unsigned long) ka->sa.sa_handler;
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regs->gr15 = 0;
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}
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set_fs(USER_DS);
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#if DEBUG_SIG
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printk("SIG deliver %d (%s:%d): sp=%p pc=%lx ra=%p\n",
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sig, current->comm, current->pid, frame, regs->pc, frame->pretcode);
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#endif
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return;
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give_sigsegv:
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if (sig == SIGSEGV)
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ka->sa.sa_handler = SIG_DFL;
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force_sig(SIGSEGV, current);
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} /* end setup_rt_frame() */
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/*****************************************************************************/
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/*
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* OK, we're invoking a handler
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*/
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static void handle_signal(unsigned long sig, siginfo_t *info,
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struct k_sigaction *ka, sigset_t *oldset,
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struct pt_regs *regs)
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{
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/* Are we from a system call? */
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if (in_syscall(regs)) {
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/* If so, check system call restarting.. */
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switch (regs->gr8) {
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case -ERESTART_RESTARTBLOCK:
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case -ERESTARTNOHAND:
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regs->gr8 = -EINTR;
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break;
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case -ERESTARTSYS:
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if (!(ka->sa.sa_flags & SA_RESTART)) {
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regs->gr8 = -EINTR;
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break;
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}
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/* fallthrough */
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case -ERESTARTNOINTR:
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regs->gr8 = regs->orig_gr8;
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regs->pc -= 4;
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}
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}
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/* Set up the stack frame */
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if (ka->sa.sa_flags & SA_SIGINFO)
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setup_rt_frame(sig, ka, info, oldset, regs);
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else
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setup_frame(sig, ka, oldset, regs);
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spin_lock_irq(¤t->sighand->siglock);
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sigorsets(¤t->blocked, ¤t->blocked, &ka->sa.sa_mask);
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|
if (!(ka->sa.sa_flags & SA_NODEFER))
|
|
sigaddset(¤t->blocked, sig);
|
|
recalc_sigpending();
|
|
spin_unlock_irq(¤t->sighand->siglock);
|
|
} /* end handle_signal() */
|
|
|
|
/*****************************************************************************/
|
|
/*
|
|
* 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.
|
|
*/
|
|
int do_signal(struct pt_regs *regs, sigset_t *oldset)
|
|
{
|
|
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 (try_to_freeze())
|
|
goto no_signal;
|
|
|
|
if (!oldset)
|
|
oldset = ¤t->blocked;
|
|
|
|
signr = get_signal_to_deliver(&info, &ka, regs, NULL);
|
|
if (signr > 0) {
|
|
handle_signal(signr, &info, &ka, oldset, regs);
|
|
return 1;
|
|
}
|
|
|
|
no_signal:
|
|
/* Did we come from a system call? */
|
|
if (regs->syscallno >= 0) {
|
|
/* Restart the system call - no handlers present */
|
|
if (regs->gr8 == -ERESTARTNOHAND ||
|
|
regs->gr8 == -ERESTARTSYS ||
|
|
regs->gr8 == -ERESTARTNOINTR) {
|
|
regs->gr8 = regs->orig_gr8;
|
|
regs->pc -= 4;
|
|
}
|
|
|
|
if (regs->gr8 == -ERESTART_RESTARTBLOCK){
|
|
regs->gr8 = __NR_restart_syscall;
|
|
regs->pc -= 4;
|
|
}
|
|
}
|
|
|
|
return 0;
|
|
} /* end do_signal() */
|
|
|
|
/*****************************************************************************/
|
|
/*
|
|
* notification of userspace execution resumption
|
|
* - triggered by current->work.notify_resume
|
|
*/
|
|
asmlinkage void do_notify_resume(__u32 thread_info_flags)
|
|
{
|
|
/* pending single-step? */
|
|
if (thread_info_flags & _TIF_SINGLESTEP)
|
|
clear_thread_flag(TIF_SINGLESTEP);
|
|
|
|
/* deal with pending signal delivery */
|
|
if (thread_info_flags & _TIF_SIGPENDING)
|
|
do_signal(__frame, NULL);
|
|
|
|
} /* end do_notify_resume() */
|