432 lines
10 KiB
C
432 lines
10 KiB
C
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/* MN10300 Signal handling
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*
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* Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
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* Written by David Howells (dhowells@redhat.com)
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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 Licence
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* as published by the Free Software Foundation; either version
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* 2 of the Licence, 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/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/stddef.h>
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#include <linux/tty.h>
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#include <linux/personality.h>
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#include <linux/suspend.h>
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#include <linux/tracehook.h>
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#include <asm/cacheflush.h>
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#include <asm/ucontext.h>
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#include <linux/uaccess.h>
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#include <asm/fpu.h>
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#include "sigframe.h"
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#define DEBUG_SIG 0
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/*
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* do a signal return; undo the signal stack.
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*/
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static int restore_sigcontext(struct pt_regs *regs,
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struct sigcontext __user *sc, long *_d0)
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{
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unsigned int err = 0;
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/* Always make any pending restarted system calls return -EINTR */
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current->restart_block.fn = do_no_restart_syscall;
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if (is_using_fpu(current))
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fpu_kill_state(current);
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#define COPY(x) err |= __get_user(regs->x, &sc->x)
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COPY(d1); COPY(d2); COPY(d3);
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COPY(a0); COPY(a1); COPY(a2); COPY(a3);
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COPY(e0); COPY(e1); COPY(e2); COPY(e3);
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COPY(e4); COPY(e5); COPY(e6); COPY(e7);
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COPY(lar); COPY(lir);
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COPY(mdr); COPY(mdrq);
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COPY(mcvf); COPY(mcrl); COPY(mcrh);
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COPY(sp); COPY(pc);
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#undef COPY
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{
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unsigned int tmpflags;
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#ifndef CONFIG_MN10300_USING_JTAG
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#define USER_EPSW (EPSW_FLAG_Z | EPSW_FLAG_N | EPSW_FLAG_C | EPSW_FLAG_V | \
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EPSW_T | EPSW_nAR)
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#else
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#define USER_EPSW (EPSW_FLAG_Z | EPSW_FLAG_N | EPSW_FLAG_C | EPSW_FLAG_V | \
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EPSW_nAR)
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#endif
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err |= __get_user(tmpflags, &sc->epsw);
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regs->epsw = (regs->epsw & ~USER_EPSW) |
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(tmpflags & USER_EPSW);
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regs->orig_d0 = -1; /* disable syscall checks */
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}
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{
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struct fpucontext *buf;
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err |= __get_user(buf, &sc->fpucontext);
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if (buf) {
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if (!access_ok(VERIFY_READ, buf, sizeof(*buf)))
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goto badframe;
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err |= fpu_restore_sigcontext(buf);
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}
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}
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err |= __get_user(*_d0, &sc->d0);
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return err;
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badframe:
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return 1;
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}
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/*
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* standard signal return syscall
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*/
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asmlinkage long sys_sigreturn(void)
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{
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struct sigframe __user *frame;
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sigset_t set;
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long d0;
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frame = (struct sigframe __user *) current_frame()->sp;
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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.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,
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sizeof(frame->extramask)))
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goto badframe;
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set_current_blocked(&set);
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if (restore_sigcontext(current_frame(), &frame->sc, &d0))
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goto badframe;
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return d0;
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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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* realtime signal return syscall
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*/
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asmlinkage long sys_rt_sigreturn(void)
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{
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struct rt_sigframe __user *frame;
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sigset_t set;
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long d0;
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frame = (struct rt_sigframe __user *) current_frame()->sp;
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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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set_current_blocked(&set);
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if (restore_sigcontext(current_frame(), &frame->uc.uc_mcontext, &d0))
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goto badframe;
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if (restore_altstack(&frame->uc.uc_stack))
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goto badframe;
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return d0;
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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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* store the userspace context into a signal frame
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*/
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static int setup_sigcontext(struct sigcontext __user *sc,
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struct fpucontext *fpuctx,
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struct pt_regs *regs,
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unsigned long mask)
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{
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int tmp, err = 0;
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#define COPY(x) err |= __put_user(regs->x, &sc->x)
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COPY(d0); COPY(d1); COPY(d2); COPY(d3);
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COPY(a0); COPY(a1); COPY(a2); COPY(a3);
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COPY(e0); COPY(e1); COPY(e2); COPY(e3);
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COPY(e4); COPY(e5); COPY(e6); COPY(e7);
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COPY(lar); COPY(lir);
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COPY(mdr); COPY(mdrq);
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COPY(mcvf); COPY(mcrl); COPY(mcrh);
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COPY(sp); COPY(epsw); COPY(pc);
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#undef COPY
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tmp = fpu_setup_sigcontext(fpuctx);
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if (tmp < 0)
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err = 1;
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else
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err |= __put_user(tmp ? fpuctx : NULL, &sc->fpucontext);
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/* non-iBCS2 extensions.. */
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err |= __put_user(mask, &sc->oldmask);
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return err;
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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 ksignal *ksig,
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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 = sigsp(regs->sp, ksig);
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return (void __user *) ((sp - frame_size) & ~7UL);
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}
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/*
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* set up a normal signal frame
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*/
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static int setup_frame(struct ksignal *ksig, sigset_t *set,
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struct pt_regs *regs)
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{
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struct sigframe __user *frame;
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int sig = ksig->sig;
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frame = get_sigframe(ksig, regs, sizeof(*frame));
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if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
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return -EFAULT;
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if (__put_user(sig, &frame->sig) < 0 ||
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__put_user(&frame->sc, &frame->psc) < 0)
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return -EFAULT;
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if (setup_sigcontext(&frame->sc, &frame->fpuctx, regs, set->sig[0]))
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return -EFAULT;
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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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return -EFAULT;
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}
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/* set up to return from userspace. If provided, use a stub already in
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* userspace */
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if (ksig->ka.sa.sa_flags & SA_RESTORER) {
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if (__put_user(ksig->ka.sa.sa_restorer, &frame->pretcode))
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return -EFAULT;
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} else {
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if (__put_user((void (*)(void))frame->retcode,
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&frame->pretcode))
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return -EFAULT;
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/* this is mov $,d0; syscall 0 */
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if (__put_user(0x2c, (char *)(frame->retcode + 0)) ||
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__put_user(__NR_sigreturn, (char *)(frame->retcode + 1)) ||
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__put_user(0x00, (char *)(frame->retcode + 2)) ||
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__put_user(0xf0, (char *)(frame->retcode + 3)) ||
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__put_user(0xe0, (char *)(frame->retcode + 4)))
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return -EFAULT;
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flush_icache_range((unsigned long) frame->retcode,
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(unsigned long) frame->retcode + 5);
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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->pc = (unsigned long) ksig->ka.sa.sa_handler;
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regs->d0 = sig;
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regs->d1 = (unsigned long) &frame->sc;
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#if DEBUG_SIG
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printk(KERN_DEBUG "SIG deliver %d (%s:%d): sp=%p pc=%lx ra=%p\n",
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sig, current->comm, current->pid, frame, regs->pc,
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frame->pretcode);
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#endif
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return 0;
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}
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/*
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* set up a realtime signal frame
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*/
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static int setup_rt_frame(struct ksignal *ksig, sigset_t *set,
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struct pt_regs *regs)
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{
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struct rt_sigframe __user *frame;
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int sig = ksig->sig;
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frame = get_sigframe(ksig, regs, sizeof(*frame));
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if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
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return -EFAULT;
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if (__put_user(sig, &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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copy_siginfo_to_user(&frame->info, &ksig->info))
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return -EFAULT;
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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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__save_altstack(&frame->uc.uc_stack, regs->sp) ||
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setup_sigcontext(&frame->uc.uc_mcontext,
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&frame->fpuctx, regs, set->sig[0]) ||
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__copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set)))
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return -EFAULT;
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/* set up to return from userspace. If provided, use a stub already in
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* userspace */
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if (ksig->ka.sa.sa_flags & SA_RESTORER) {
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if (__put_user(ksig->ka.sa.sa_restorer, &frame->pretcode))
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return -EFAULT;
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} else {
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if (__put_user((void(*)(void))frame->retcode,
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&frame->pretcode) ||
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/* This is mov $,d0; syscall 0 */
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__put_user(0x2c, (char *)(frame->retcode + 0)) ||
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__put_user(__NR_rt_sigreturn,
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(char *)(frame->retcode + 1)) ||
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__put_user(0x00, (char *)(frame->retcode + 2)) ||
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__put_user(0xf0, (char *)(frame->retcode + 3)) ||
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__put_user(0xe0, (char *)(frame->retcode + 4)))
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return -EFAULT;
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flush_icache_range((u_long) frame->retcode,
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(u_long) frame->retcode + 5);
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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->pc = (unsigned long) ksig->ka.sa.sa_handler;
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regs->d0 = sig;
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regs->d1 = (long) &frame->info;
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#if DEBUG_SIG
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printk(KERN_DEBUG "SIG deliver %d (%s:%d): sp=%p pc=%lx ra=%p\n",
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sig, current->comm, current->pid, frame, regs->pc,
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frame->pretcode);
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#endif
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return 0;
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}
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static inline void stepback(struct pt_regs *regs)
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{
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regs->pc -= 2;
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regs->orig_d0 = -1;
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}
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/*
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* handle the actual delivery of a signal to userspace
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*/
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static int handle_signal(struct ksignal *ksig, struct pt_regs *regs)
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{
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sigset_t *oldset = sigmask_to_save();
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int ret;
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/* Are we from a system call? */
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if (regs->orig_d0 >= 0) {
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/* If so, check system call restarting.. */
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switch (regs->d0) {
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case -ERESTART_RESTARTBLOCK:
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case -ERESTARTNOHAND:
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regs->d0 = -EINTR;
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break;
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case -ERESTARTSYS:
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if (!(ksig->ka.sa.sa_flags & SA_RESTART)) {
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regs->d0 = -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->d0 = regs->orig_d0;
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stepback(regs);
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}
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}
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/* Set up the stack frame */
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if (ksig->ka.sa.sa_flags & SA_SIGINFO)
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ret = setup_rt_frame(ksig, oldset, regs);
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else
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ret = setup_frame(ksig, oldset, regs);
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signal_setup_done(ret, ksig, test_thread_flag(TIF_SINGLESTEP));
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return 0;
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}
|
||
|
|
|
||
|
|
/*
|
||
|
|
* handle a potential signal
|
||
|
|
*/
|
||
|
|
static void do_signal(struct pt_regs *regs)
|
||
|
|
{
|
||
|
|
struct ksignal ksig;
|
||
|
|
|
||
|
|
if (get_signal(&ksig)) {
|
||
|
|
handle_signal(&ksig, regs);
|
||
|
|
return;
|
||
|
|
}
|
||
|
|
|
||
|
|
/* did we come from a system call? */
|
||
|
|
if (regs->orig_d0 >= 0) {
|
||
|
|
/* restart the system call - no handlers present */
|
||
|
|
switch (regs->d0) {
|
||
|
|
case -ERESTARTNOHAND:
|
||
|
|
case -ERESTARTSYS:
|
||
|
|
case -ERESTARTNOINTR:
|
||
|
|
regs->d0 = regs->orig_d0;
|
||
|
|
stepback(regs);
|
||
|
|
break;
|
||
|
|
|
||
|
|
case -ERESTART_RESTARTBLOCK:
|
||
|
|
regs->d0 = __NR_restart_syscall;
|
||
|
|
stepback(regs);
|
||
|
|
break;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
/* if there's no signal to deliver, we just put the saved sigmask
|
||
|
|
* back */
|
||
|
|
restore_saved_sigmask();
|
||
|
|
}
|
||
|
|
|
||
|
|
/*
|
||
|
|
* notification of userspace execution resumption
|
||
|
|
* - triggered by current->work.notify_resume
|
||
|
|
*/
|
||
|
|
asmlinkage void do_notify_resume(struct pt_regs *regs, u32 thread_info_flags)
|
||
|
|
{
|
||
|
|
/* Pending single-step? */
|
||
|
|
if (thread_info_flags & _TIF_SINGLESTEP) {
|
||
|
|
#ifndef CONFIG_MN10300_USING_JTAG
|
||
|
|
regs->epsw |= EPSW_T;
|
||
|
|
clear_thread_flag(TIF_SINGLESTEP);
|
||
|
|
#else
|
||
|
|
BUG(); /* no h/w single-step if using JTAG unit */
|
||
|
|
#endif
|
||
|
|
}
|
||
|
|
|
||
|
|
/* deal with pending signal delivery */
|
||
|
|
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(current_frame());
|
||
|
|
}
|
||
|
|
}
|