- 根目录:
- arch
- mn10300
- kernel
- signal.c
/* MN10300 Signal handling
*
* Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
* Written by David Howells (dhowells@redhat.com)
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public Licence
* as published by the Free Software Foundation; either version
* 2 of the Licence, or (at your option) any later version.
*/
#include <linux/sched.h>
#include <linux/mm.h>
#include <linux/smp.h>
#include <linux/kernel.h>
#include <linux/signal.h>
#include <linux/errno.h>
#include <linux/wait.h>
#include <linux/ptrace.h>
#include <linux/unistd.h>
#include <linux/stddef.h>
#include <linux/tty.h>
#include <linux/personality.h>
#include <linux/suspend.h>
#include <linux/tracehook.h>
#include <asm/cacheflush.h>
#include <asm/ucontext.h>
#include <asm/uaccess.h>
#include <asm/fpu.h>
#include "sigframe.h"
#define DEBUG_SIG 0
/*
* do a signal return; undo the signal stack.
*/
static int restore_sigcontext(struct pt_regs *regs,
struct sigcontext __user *sc, long *_d0)
{
unsigned int err = 0;
/* Always make any pending restarted system calls return -EINTR */
current->restart_block.fn = do_no_restart_syscall;
if (is_using_fpu(current))
fpu_kill_state(current);
#define COPY(x) err |= __get_user(regs->x, &sc->x)
COPY(d1); COPY(d2); COPY(d3);
COPY(a0); COPY(a1); COPY(a2); COPY(a3);
COPY(e0); COPY(e1); COPY(e2); COPY(e3);
COPY(e4); COPY(e5); COPY(e6); COPY(e7);
COPY(lar); COPY(lir);
COPY(mdr); COPY(mdrq);
COPY(mcvf); COPY(mcrl); COPY(mcrh);
COPY(sp); COPY(pc);
#undef COPY
{
unsigned int tmpflags;
#ifndef CONFIG_MN10300_USING_JTAG
#define USER_EPSW (EPSW_FLAG_Z | EPSW_FLAG_N | EPSW_FLAG_C | EPSW_FLAG_V | \
EPSW_T | EPSW_nAR)
#else
#define USER_EPSW (EPSW_FLAG_Z | EPSW_FLAG_N | EPSW_FLAG_C | EPSW_FLAG_V | \
EPSW_nAR)
#endif
err |= __get_user(tmpflags, &sc->epsw);
regs->epsw = (regs->epsw & ~USER_EPSW) |
(tmpflags & USER_EPSW);
regs->orig_d0 = -1; /* disable syscall checks */
}
{
struct fpucontext *buf;
err |= __get_user(buf, &sc->fpucontext);
if (buf) {
if (verify_area(VERIFY_READ, buf, sizeof(*buf)))
goto badframe;
err |= fpu_restore_sigcontext(buf);
}
}
err |= __get_user(*_d0, &sc->d0);
return err;
badframe:
return 1;
}
/*
* standard signal return syscall
*/
asmlinkage long sys_sigreturn(void)
{
struct sigframe __user *frame;
sigset_t set;
long d0;
frame = (struct sigframe __user *) current_frame()->sp;
if (verify_area(VERIFY_READ, frame, sizeof(*frame)))
goto badframe;
if (__get_user(set.sig[0], &frame->sc.oldmask))
goto badframe;
if (_NSIG_WORDS > 1 &&
__copy_from_user(&set.sig[1], &frame->extramask,
sizeof(frame->extramask)))
goto badframe;
set_current_blocked(&set);
if (restore_sigcontext(current_frame(), &frame->sc, &d0))
goto badframe;
return d0;
badframe:
force_sig(SIGSEGV, current);
return 0;
}
/*
* realtime signal return syscall
*/
asmlinkage long sys_rt_sigreturn(void)
{
struct rt_sigframe __user *frame;
sigset_t set;
long d0;
frame = (struct rt_sigframe __user *) current_frame()->sp;
if (verify_area(VERIFY_READ, frame, sizeof(*frame)))
goto badframe;
if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set)))
goto badframe;
set_current_blocked(&set);
if (restore_sigcontext(current_frame(), &frame->uc.uc_mcontext, &d0))
goto badframe;
if (restore_altstack(&frame->uc.uc_stack))
goto badframe;
return d0;
badframe:
force_sig(SIGSEGV, current);
return 0;
}
/*
* store the userspace context into a signal frame
*/
static int setup_sigcontext(struct sigcontext __user *sc,
struct fpucontext *fpuctx,
struct pt_regs *regs,
unsigned long mask)
{
int tmp, err = 0;
#define COPY(x) err |= __put_user(regs->x, &sc->x)
COPY(d0); COPY(d1); COPY(d2); COPY(d3);
COPY(a0); COPY(a1); COPY(a2); COPY(a3);
COPY(e0); COPY(e1); COPY(e2); COPY(e3);
COPY(e4); COPY(e5); COPY(e6); COPY(e7);
COPY(lar); COPY(lir);
COPY(mdr); COPY(mdrq);
COPY(mcvf); COPY(mcrl); COPY(mcrh);
COPY(sp); COPY(epsw); COPY(pc);
#undef COPY
tmp = fpu_setup_sigcontext(fpuctx);
if (tmp < 0)
err = 1;
else
err |= __put_user(tmp ? fpuctx : NULL, &sc->fpucontext);
/* non-iBCS2 extensions.. */
err |= __put_user(mask, &sc->oldmask);
return err;
}
/*
* determine which stack to use..
*/
static inline void __user *get_sigframe(struct ksignal *ksig,
struct pt_regs *regs,
size_t frame_size)
{
unsigned long sp = sigsp(regs->sp, ksig);
return (void __user *) ((sp - frame_size) & ~7UL);
}
/*
* set up a normal signal frame
*/
static int setup_frame(struct ksignal *ksig, sigset_t *set,
struct pt_regs *regs)
{
struct sigframe __user *frame;
int sig = ksig->sig;
frame = get_sigframe(ksig, regs, sizeof(*frame));
if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
return -EFAULT;
if (__put_user(sig, &frame->sig) < 0 ||
__put_user(&frame->sc, &frame->psc) < 0)
return -EFAULT;
if (setup_sigcontext(&frame->sc, &frame->fpuctx, regs, set->sig[0]))
return -EFAULT;
if (_NSIG_WORDS > 1) {
if (__copy_to_user(frame->extramask, &set->sig[1],
sizeof(frame->extramask)))
return -EFAULT;
}
/* set up to return from userspace. If provided, use a stub already in
* userspace */
if (ksig->ka.sa.sa_flags & SA_RESTORER) {
if (__put_user(ksig->ka.sa.sa_restorer, &frame->pretcode))
return -EFAULT;
} else {
if (__put_user((void (*)(void))frame->retcode,
&frame->pretcode))
return -EFAULT;
/* this is mov $,d0; syscall 0 */
if (__put_user(0x2c, (char *)(frame->retcode + 0)) ||
__put_user(__NR_sigreturn, (char *)(frame->retcode + 1)) ||
__put_user(0x00, (char *)(frame->retcode + 2)) ||
__put_user(0xf0, (char *)(frame->retcode + 3)) ||
__put_user(0xe0, (char *)(frame->retcode + 4)))
return -EFAULT;
flush_icache_range((unsigned long) frame->retcode,
(unsigned long) frame->retcode + 5);
}
/* set up registers for signal handler */
regs->sp = (unsigned long) frame;
regs->pc = (unsigned long) ksig->ka.sa.sa_handler;
regs->d0 = sig;
regs->d1 = (unsigned long) &frame->sc;
#if DEBUG_SIG
printk(KERN_DEBUG "SIG deliver %d (%s:%d): sp=%p pc=%lx ra=%p\n",
sig, current->comm, current->pid, frame, regs->pc,
frame->pretcode);
#endif
return 0;
}
/*
* set up a realtime signal frame
*/
static int setup_rt_frame(struct ksignal *ksig, sigset_t *set,
struct pt_regs *regs)
{
struct rt_sigframe __user *frame;
int sig = ksig->sig;
frame = get_sigframe(ksig, regs, sizeof(*frame));
if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
return -EFAULT;
if (__put_user(sig, &frame->sig) ||
__put_user(&frame->info, &frame->pinfo) ||
__put_user(&frame->uc, &frame->puc) ||
copy_siginfo_to_user(&frame->info, &ksig->info))
return -EFAULT;
/* create the ucontext. */
if (__put_user(0, &frame->uc.uc_flags) ||
__put_user(0, &frame->uc.uc_link) ||
__save_altstack(&frame->uc.uc_stack, regs->sp) ||
setup_sigcontext(&frame->uc.uc_mcontext,
&frame->fpuctx, regs, set->sig[0]) ||
__copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set)))
return -EFAULT;
/* set up to return from userspace. If provided, use a stub already in
* userspace */
if (ksig->ka.sa.sa_flags & SA_RESTORER) {
if (__put_user(ksig->ka.sa.sa_restorer, &frame->pretcode))
return -EFAULT;
} else {
if (__put_user((void(*)(void))frame->retcode,
&frame->pretcode) ||
/* This is mov $,d0; syscall 0 */
__put_user(0x2c, (char *)(frame->retcode + 0)) ||
__put_user(__NR_rt_sigreturn,
(char *)(frame->retcode + 1)) ||
__put_user(0x00, (char *)(frame->retcode + 2)) ||
__put_user(0xf0, (char *)(frame->retcode + 3)) ||
__put_user(0xe0, (char *)(frame->retcode + 4)))
return -EFAULT;
flush_icache_range((u_long) frame->retcode,
(u_long) frame->retcode + 5);
}
/* Set up registers for signal handler */
regs->sp = (unsigned long) frame;
regs->pc = (unsigned long) ksig->ka.sa.sa_handler;
regs->d0 = sig;
regs->d1 = (long) &frame->info;
#if DEBUG_SIG
printk(KERN_DEBUG "SIG deliver %d (%s:%d): sp=%p pc=%lx ra=%p\n",
sig, current->comm, current->pid, frame, regs->pc,
frame->pretcode);
#endif
return 0;
}
static inline void stepback(struct pt_regs *regs)
{
regs->pc -= 2;
regs->orig_d0 = -1;
}
/*
* handle the actual delivery of a signal to userspace
*/
static int handle_signal(struct ksignal *ksig, struct pt_regs *regs)
{
sigset_t *oldset = sigmask_to_save();
int ret;
/* Are we from a system call? */
if (regs->orig_d0 >= 0) {
/* If so, check system call restarting.. */
switch (regs->d0) {
case -ERESTART_RESTARTBLOCK:
case -ERESTARTNOHAND:
regs->d0 = -EINTR;
break;
case -ERESTARTSYS:
if (!(ksig->ka.sa.sa_flags & SA_RESTART)) {
regs->d0 = -EINTR;
break;
}
/* fallthrough */
case -ERESTARTNOINTR:
regs->d0 = regs->orig_d0;
stepback(regs);
}
}
/* Set up the stack frame */
if (ksig->ka.sa.sa_flags & SA_SIGINFO)
ret = setup_rt_frame(ksig, oldset, regs);
else
ret = setup_frame(ksig, oldset, regs);
signal_setup_done(ret, ksig, test_thread_flag(TIF_SINGLESTEP));
return 0;
}
/*
* 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());
}
}