freebsd-skq/sys/i386/linux/linux_copyout.c
kib a42a93a102 Fix futexes on i386 after the 4/4G split.
Use proper method to access userspace.  For now, only the slow copyout
path is implemented.

Reported and tested by:	tijl (previous version)
Sponsored by:	The FreeBSD Foundation
2018-04-24 12:50:21 +00:00

179 lines
4.1 KiB
C

/*-
* SPDX-License-Identifier: BSD-2-Clause-FreeBSD
*
* Copyright (c) 2018 The FreeBSD Foundation
* All rights reserved.
*
* This software was developed by Konstantin Belousov <kib@FreeBSD.org>
* under sponsorship from the FreeBSD Foundation.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include "opt_compat.h"
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/imgact.h>
#include <sys/lock.h>
#include <sys/sx.h>
#include <vm/vm.h>
#include <vm/vm_param.h>
#include <vm/vm_extern.h>
#include <vm/pmap.h>
#include <machine/atomic.h>
#include <machine/md_var.h>
#include <compat/linux/linux_emul.h>
#include <compat/linux/linux_futex.h>
struct futex_st0 {
int oparg;
int *oldval;
};
static void
futex_xchgl_slow0(vm_offset_t kva, void *arg)
{
struct futex_st0 *st;
st = arg;
*st->oldval = atomic_swap_int((int *)kva, st->oparg);
}
int
futex_xchgl(int oparg, uint32_t *uaddr, int *oldval)
{
struct futex_st0 st;
st.oparg = oparg;
st.oldval = oldval;
if (cp_slow0((vm_offset_t)uaddr, sizeof(uint32_t), true,
futex_xchgl_slow0, &st) != 0)
return (-EFAULT);
return (0);
}
static void
futex_addl_slow0(vm_offset_t kva, void *arg)
{
struct futex_st0 *st;
st = arg;
*st->oldval = atomic_fetchadd_int((int *)kva, st->oparg);
}
int
futex_addl(int oparg, uint32_t *uaddr, int *oldval)
{
struct futex_st0 st;
st.oparg = oparg;
st.oldval = oldval;
if (cp_slow0((vm_offset_t)uaddr, sizeof(uint32_t), true,
futex_addl_slow0, &st) != 0)
return (-EFAULT);
return (0);
}
static void
futex_orl_slow0(vm_offset_t kva, void *arg)
{
struct futex_st0 *st;
int old;
st = arg;
old = *(int *)kva;
while (!atomic_fcmpset_int((int *)kva, &old, old | st->oparg))
;
*st->oldval = old;
}
int
futex_orl(int oparg, uint32_t *uaddr, int *oldval)
{
struct futex_st0 st;
st.oparg = oparg;
st.oldval = oldval;
if (cp_slow0((vm_offset_t)uaddr, sizeof(uint32_t), true,
futex_orl_slow0, &st) != 0)
return (-EFAULT);
return (0);
}
static void
futex_andl_slow0(vm_offset_t kva, void *arg)
{
struct futex_st0 *st;
int old;
st = arg;
old = *(int *)kva;
while (!atomic_fcmpset_int((int *)kva, &old, old & st->oparg))
;
*st->oldval = old;
}
int
futex_andl(int oparg, uint32_t *uaddr, int *oldval)
{
struct futex_st0 st;
st.oparg = oparg;
st.oldval = oldval;
if (cp_slow0((vm_offset_t)uaddr, sizeof(uint32_t), true,
futex_andl_slow0, &st) != 0)
return (-EFAULT);
return (0);
}
static void
futex_xorl_slow0(vm_offset_t kva, void *arg)
{
struct futex_st0 *st;
int old;
st = arg;
old = *(int *)kva;
while (!atomic_fcmpset_int((int *)kva, &old, old ^ st->oparg))
;
*st->oldval = old;
}
int
futex_xorl(int oparg, uint32_t *uaddr, int *oldval)
{
struct futex_st0 st;
st.oparg = oparg;
st.oldval = oldval;
if (cp_slow0((vm_offset_t)uaddr, sizeof(uint32_t), true,
futex_xorl_slow0, &st) != 0)
return (-EFAULT);
return (0);
}