/*      $NetBSD: linux32_mod.c,v 1.15 2021/11/25 02:38:56 ryo Exp $     */

/*-
* Copyright (c) 2008 The NetBSD Foundation, Inc.
* All rights reserved.
*
* This code is derived from software developed for The NetBSD Foundation
* by Andrew Doran.
*
* 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: linux32_mod.c,v 1.15 2021/11/25 02:38:56 ryo Exp $");

#ifdef _KERNEL_OPT
#include "opt_execfmt.h"
#endif

#ifndef ELFSIZE
#define ELFSIZE ARCH_ELFSIZE
#endif

#include <sys/param.h>
#include <sys/module.h>
#include <sys/exec.h>
#include <sys/signalvar.h>
#include <sys/sysctl.h>

#include <compat/linux/common/linux_exec.h>

#include <compat/linux32/common/linux32_sysctl.h>
#include <compat/linux32/common/linux32_exec.h>

#if defined(EXEC_ELF32)
# define       MD1     ",exec_elf32,compat_netbsd32,compat_netbsd32_sysvipc"
#else
# define       MD1     ""
#endif

#define REQ1    "compat_linux,sysv_ipc,compat_sysv_50"
#define REQ2    ",compat_netbsd32_50,compat_netbsd32_43"

MODULE(MODULE_CLASS_EXEC, compat_linux32, REQ1 REQ2 MD1);

static struct execsw linux32_execsw[] = {
#if defined(EXEC_ELF32)
       {
               .es_hdrsz = sizeof (Elf32_Ehdr),
               .es_makecmds = exec_elf32_makecmds,
               .u = {
                       .elf_probe_func = linux32_elf32_probe,
               },
               .es_emul = &emul_linux32,
               .es_prio = EXECSW_PRIO_ANY,
               .es_arglen = LINUX32_ELF_AUX_ARGSIZ,
               .es_copyargs = linux32_elf32_copyargs,
               .es_setregs = NULL,
               .es_coredump = coredump_elf32,
               .es_setup_stack = linux32_exec_setup_stack,
       },
#endif
};

int linux32_enabled = 1;

int
linux32_sysctl_enable(SYSCTLFN_ARGS)
{
       struct sysctlnode node;
       int error, val;

       val = *(int *)rnode->sysctl_data;

       node = *rnode;
       node.sysctl_data = &val;

       error = sysctl_lookup(SYSCTLFN_CALL(&node));
       if (error != 0 || newp == NULL)
               return error;

       if (val == *(int *)rnode->sysctl_data)
               return 0;

       if (val == 1)
               error = exec_add(linux32_execsw, __arraycount(linux32_execsw));
       else if (val == 0)
               error =
                   exec_remove(linux32_execsw, __arraycount(linux32_execsw));
       else
               error = EINVAL;

       if (error)
               return error;

       *(int *)rnode->sysctl_data = val;

       return 0;
}

static int
compat_linux32_modcmd(modcmd_t cmd, void *arg)
{
       int error;

       switch (cmd) {
       case MODULE_CMD_INIT:
               error = exec_add(linux32_execsw, __arraycount(linux32_execsw));
               return error;

       case MODULE_CMD_FINI:
               error =
                   exec_remove(linux32_execsw, __arraycount(linux32_execsw));
               if (error)
                       return error;
               linux32_sysctl_fini();
               return 0;

       default:
               return ENOTTY;
       }
}