/* $NetBSD: linux_exec.c,v 1.124 2020/05/03 01:06:56 thorpej Exp $ */

/* $NetBSD: linux_exec.c,v 1.124 2020/05/03 01:06:56 thorpej Exp $ */

/*-
* Copyright (c) 1994, 1995, 1998, 2000, 2007, 2008, 2020
* The NetBSD Foundation, Inc.
* All rights reserved.
*
* This code is derived from software contributed to The NetBSD Foundation
* by Christos Zoulas, Frank van der Linden, Eric Haszlakiewicz and
* Thor Lancelot Simon.
*
* 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 NETBSD FOUNDATION, INC. 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 FOUNDATION 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>
__KERNEL_RCSID(0, "$NetBSD: linux_exec.c,v 1.124 2020/05/03 01:06:56 thorpej Exp $");

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/lwp.h>
#include <sys/proc.h>
#include <sys/namei.h>
#include <sys/vnode.h>
#include <sys/mount.h>
#include <sys/exec.h>
#include <sys/exec_elf.h>
#include <sys/futex.h>

#include <sys/mman.h>
#include <sys/syscallargs.h>

#include <sys/ptrace.h> /* For proc_reparent() */

#include <uvm/uvm_extern.h>

#include <sys/cpu.h>
#include <machine/reg.h>

#include <compat/linux/common/linux_types.h>
#include <compat/linux/common/linux_signal.h>
#include <compat/linux/common/linux_util.h>
#include <compat/linux/common/linux_sched.h>
#include <compat/linux/common/linux_machdep.h>
#include <compat/linux/common/linux_misc.h>
#include <compat/linux/common/linux_exec.h>
#include <compat/linux/common/linux_ipc.h>
#include <compat/linux/common/linux_sem.h>

#include <compat/linux/linux_syscallargs.h>
#include <compat/linux/linux_syscall.h>
#include <compat/linux/common/linux_misc.h>
#include <compat/linux/common/linux_errno.h>
#include <compat/linux/common/linux_emuldata.h>

extern struct sysent linux_sysent[];
extern const uint32_t linux_sysent_nomodbits[];
extern const char * const linux_syscallnames[];
extern char linux_sigcode[], linux_esigcode[];

/*
* Emulation switch.
*/

struct uvm_object *emul_linux_object;

struct emul emul_linux = {
.e_name = "linux",
.e_path = "/emul/linux",
#ifndef __HAVE_MINIMAL_EMUL
.e_flags = 0,
.e_errno = native_to_linux_errno,
.e_nosys = LINUX_SYS_syscall,
.e_nsysent = LINUX_SYS_NSYSENT,
#endif
.e_sysent = linux_sysent,
.e_nomodbits = linux_sysent_nomodbits,
.e_syscallnames = linux_syscallnames,
.e_sendsig = linux_sendsig,
.e_trapsignal = linux_trapsignal,
.e_sigcode = linux_sigcode,
.e_esigcode = linux_esigcode,
.e_sigobject = &emul_linux_object,
.e_setregs = linux_setregs,
.e_proc_exec = linux_e_proc_exec,
.e_proc_fork = linux_e_proc_fork,
.e_proc_exit = linux_e_proc_exit,
.e_lwp_fork = linux_e_lwp_fork,
.e_lwp_exit = linux_e_lwp_exit,
#ifdef __HAVE_SYSCALL_INTERN
.e_syscall_intern = linux_syscall_intern,
#else
#error Implement __HAVE_SYSCALL_INTERN for this platform
#endif
.e_sysctlovly = NULL,
.e_vm_default_addr = uvm_default_mapaddr,
.e_usertrap = linux_usertrap,
.e_ucsize = 0,
.e_startlwp = NULL
};

void
linux_e_proc_exec(struct proc *p, struct exec_package *epp)
{
struct lwp *l;

l = LIST_FIRST(&p->p_lwps);
if (l->l_emuldata == NULL) {
l->l_emuldata = kmem_zalloc(sizeof(struct linux_emuldata), KM_SLEEP);
} else {
memset(l->l_emuldata, 0, sizeof (struct linux_emuldata));
}

KASSERT(p->p_nlwps == 1);
}

void
linux_e_proc_exit(struct proc *p)
{
struct lwp *l;

KASSERT(p->p_nlwps == 1);
l = LIST_FIRST(&p->p_lwps);
linux_e_lwp_exit(l);
}

void
linux_e_proc_fork(struct proc *p2, struct lwp *l1, int flags)
{
struct linux_emuldata *led1, *led2;
struct lwp *l2;

KASSERT(p2->p_nlwps == 1);
l2 = LIST_FIRST(&p2->p_lwps);
led1 = l1->l_emuldata;
led2 = l2->l_emuldata;
led2->led_child_tidptr = led1->led_child_tidptr;
}

void
linux_e_lwp_fork(struct lwp *l1, struct lwp *l2)
{
struct linux_emuldata *led2;

led2 = kmem_zalloc(sizeof(*led2), KM_SLEEP);
l2->l_emuldata = led2;
}

void
linux_e_lwp_exit(struct lwp *l)
{
struct linux_emuldata *led;
register_t retval;
int error, zero = 0;

led = l->l_emuldata;

if (led->led_clear_tid != NULL) {
/* Emulate LINUX_CLONE_CHILD_CLEARTID */
error = copyout(&zero, led->led_clear_tid, sizeof(zero));
#ifdef DEBUG_LINUX
if (error != 0)
printf("%s: cannot clear TID\n", __func__);
#endif

error = linux_do_futex((int *)led->led_clear_tid, FUTEX_WAKE,
INT_MAX, NULL, NULL, 0, 0, &retval);
if (error)
printf("%s: linux_sys_futex failed\n", __func__);
}

led = l->l_emuldata;
l->l_emuldata = NULL;
kmem_free(led, sizeof(*led));
}