linux/arch/mips/kernel/signal32.c

/*
 * 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.
 *
 * Copyright (C) 1991, 1992  Linus Torvalds
 * Copyright (C) 1994 - 2000, 2006  Ralf Baechle
 * Copyright (C) 1999, 2000 Silicon Graphics, Inc.
 * Copyright (C) 2016, Imagination Technologies Ltd.
 */
#include <linux/compat.h>
#include <linux/compiler.h>
#include <linux/errno.h>
#include <linux/kernel.h>
#include <linux/signal.h>
#include <linux/syscalls.h>

#include <asm/compat-signal.h>
#include <linux/uaccess.h>
#include <asm/unistd.h>

#include "signal-common.h"

/* 32-bit compatibility types */

typedef unsigned int __sighandler32_t;
typedef void (*vfptr_t)(void);

/*
 * Atomically swap in the new signal mask, and wait for a signal.
 */

asmlinkage int sys32_sigsuspend(compat_sigset_t __user *uset)
{
	return compat_sys_rt_sigsuspend(uset, sizeof(compat_sigset_t));
}

SYSCALL_DEFINE3(32_sigaction, long, sig, const struct compat_sigaction __user *, act,
	struct compat_sigaction __user *, oact)
{
	struct k_sigaction new_ka, old_ka;
	int ret;
	int err = 0;

	if (act) {
		old_sigset_t mask;
		s32 handler;

		if (!access_ok(VERIFY_READ, act, sizeof(*act)))
			return -EFAULT;
		err |= __get_user(handler, &act->sa_handler);
		new_ka.sa.sa_handler = (void __user *)(s64)handler;
		err |= __get_user(new_ka.sa.sa_flags, &act->sa_flags);
		err |= __get_user(mask, &act->sa_mask.sig[0]);
		if (err)
			return -EFAULT;

		siginitset(&new_ka.sa.sa_mask, mask);
	}

	ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL);

	if (!ret && oact) {
		if (!access_ok(VERIFY_WRITE, oact, sizeof(*oact)))
			return -EFAULT;
		err |= __put_user(old_ka.sa.sa_flags, &oact->sa_flags);
		err |= __put_user((u32)(u64)old_ka.sa.sa_handler,
				  &oact->sa_handler);
		err |= __put_user(old_ka.sa.sa_mask.sig[0], oact->sa_mask.sig);
		err |= __put_user(0, &oact->sa_mask.sig[1]);
		err |= __put_user(0, &oact->sa_mask.sig[2]);
		err |= __put_user(0, &oact->sa_mask.sig[3]);
		if (err)
			return -EFAULT;
	}

	return ret;
}