path: root/arch/m68k/kernel/signal_mm.c

/*
 *  linux/arch/m68k/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.
 */

/*
 * Linux/m68k support by Hamish Macdonald
 *
 * 68060 fixes by Jesper Skov
 *
 * 1997-12-01  Modified for POSIX.1b signals by Andreas Schwab
 *
 * mathemu support by Roman Zippel
 *  (Note: fpstate in the signal context is completely ignored for the emulator
 *         and the internal floating point format is put on stack)
 */

/*
 * ++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 <linux/sched.h>
#include <linux/mm.h>
#include <linux/kernel.h>
#include <linux/signal.h>
#include <linux/syscalls.h>
#include <linux/errno.h>
#include <linux/wait.h>
#include <linux/ptrace.h>
#include <linux/unistd.h>
#include <linux/stddef.h>
#include <linux/highuid.h>
#include <linux/personality.h>
#include <linux/tty.h>
#include <linux/binfmts.h>
#include <linux/module.h>

#include <asm/setup.h>
#include <asm/uaccess.h>
#include <asm/pgtable.h>
#include <asm/traps.h>
#include <asm/ucontext.h>

#define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP)))

static const int frame_extra_sizes[16] = {
  [1]	= -1, /* sizeof(((struct frame *)0)->un.fmt1), */
  [2]	= sizeof(((struct frame *)0)->un.fmt2),
  [3]	= sizeof(((struct frame *)0)->un.fmt3),
#ifdef CONFIG_COLDFIRE
  [4]	= 0,
#else
  [4]	= sizeof(((struct frame *)0)->un.fmt4),
#endif
  [5]	= -1, /* sizeof(((struct frame *)0)->un.fmt5), */
  [6]	= -1, /* sizeof(((struct frame *)0)->un.fmt6), */
  [7]	= sizeof(((struct frame *)0)->un.fmt7),
  [8]	= -1, /* sizeof(((struct frame *)0)->un.fmt8), */
  [9]	= sizeof(((struct frame *)0)->un.fmt9),
  [10]	= sizeof(((struct frame *)0)->un.fmta),
  [11]	= sizeof(((struct frame *)0)->un.fmtb),
  [12]	= -1, /* sizeof(((struct frame *)0)->un.fmtc), */
  [13]	= -1, /* sizeof(((struct frame *)0)->un.fmtd), */
  [14]	= -1, /* sizeof(((struct frame *)0)->un.fmte), */
  [15]	= -1, /* sizeof(((struct frame *)0)->un.fmtf), */
};

int handle_kernel_fault(struct pt_regs *regs)
{
	const struct exception_table_entry *fixup;
	struct pt_regs *tregs;

	/* Are we prepared to handle this kernel fault? */
	fixup = search_exception_tables(regs->pc);
	if (!fixup)
		return 0;

	/* Create a new four word stack frame, discarding the old one. */
	regs->stkadj = frame_extra_sizes[regs->format];
	tregs =	(struct pt_regs *)((long)regs + regs->stkadj);
	tregs->vector = regs->vector;
#ifdef CONFIG_COLDFIRE
	tregs->format = 4;
#else
	tregs->format = 0;
#endif
	tregs->pc = fixup->fixup;
	tregs->sr = regs->sr;

	return 1;
}

/*
 * Atomically swap in the new signal mask, and wait for a signal.
 */
asmlinkage int
sys_sigsuspend(int unused0, int unused1, old_sigset_t mask)
{
	mask &= _BLOCKABLE;
	spin_lock_irq(&current->sighand->siglock);
	current->saved_sigmask = current->blocked;
	siginitset(&current->blocked, mask);
	recalc_sigpending();
	spin_unlock_irq(&current->sighand->siglock);

	current->state = TASK_INTERRUPTIBLE;
	schedule();
	set_restore_sigmask();

	return -ERESTARTNOHAND;
}

asmlinkage int
sys_sigaction(int sig, const struct old_sigaction __user *act,
	      struct old_sigaction __user *oact)
{
	struct k_sigaction new_ka, old_ka;
	int ret;