sys/kern/imgact_aout.c

/*
 * Copyright (c) 1993, David Greenman
 * All rights reserved.
 *
 * 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.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *      This product includes software developed by David Greenman
 * 4. The name of the developer may be used to endorse or promote products
 *    derived from this software without specific prior written permission.
 *
 * 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 REGENTS 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.
 *
 *      $Id: imgact_aout.c,v 1.3 1993/12/30 01:39:29 davidg Exp $
 */

#include "param.h"
#include "systm.h"
#include "resourcevar.h"
#include "exec.h"
#include "mman.h"
#include "imgact.h"
#include "kernel.h"

#include "vm/vm.h"

int
exec_aout_imgact(iparams)
        struct image_params *iparams;
{
        struct exec *a_out = (struct exec *) iparams->image_header;
        struct vmspace *vmspace = iparams->proc->p_vmspace;
        unsigned long vmaddr, virtual_offset, file_offset;
        unsigned long bss_size;
        int error, len;

        /*
         * Set file/virtual offset based on a.out variant.
         *      We do two cases: host byte order and network byte order
         *      (for NetBSD compatibility)
         */
        switch ((int)(a_out->a_magic & 0xffff)) {
        case ZMAGIC:
                virtual_offset = 0;
                if (a_out->a_text) {
                        file_offset = NBPG;
                } else {
                        /* Bill's "screwball mode" */
                        file_offset = 0;
                }
                break;
        case QMAGIC:
                virtual_offset = NBPG;
                file_offset = 0;
                break;
        default:
                /* NetBSD compatibility */
                switch ((int)(ntohl(a_out->a_magic) & 0xffff)) {
                case ZMAGIC:
                case QMAGIC:
                        virtual_offset = NBPG;
                        file_offset = 0;
                        break;
                default:
                        return (-1);
                }
        }

        bss_size = roundup(a_out->a_bss, NBPG);

        /*
         * Check various fields in header for validity/bounds.
         */
        if (/* entry point must lay with text region */
            a_out->a_entry < virtual_offset ||
            a_out->a_entry >= virtual_offset + a_out->a_text ||

            /* text and data size must each be page rounded */
            a_out->a_text % NBPG ||
            a_out->a_data % NBPG)
                return (-1);

        /* text + data can't exceed file size */
        if (a_out->a_data + a_out->a_text > iparams->attr->va_size)
                return (EFAULT);

        /*
         * text/data/bss must not exceed limits
         */
        if (/* text can't exceed maximum text size */
            a_out->a_text > MAXTSIZ ||

            /* data + bss can't exceed maximum data size */
            a_out->a_data + bss_size > MAXDSIZ ||

            /* data + bss can't exceed rlimit */
            a_out->a_data + bss_size >
                iparams->proc->p_rlimit[RLIMIT_DATA].rlim_cur)
                        return (ENOMEM);

        /* copy in arguments and/or environment from old process */
        error = exec_extract_strings(iparams);
        if (error)
                return (error);

        /*
         * Destroy old process VM and create a new one (with a new stack)
         */
        exec_new_vmspace(iparams);

        /*
         * Map text read/execute
         */
        vmaddr = virtual_offset;
        error =
            vm_mmap(&vmspace->vm_map,                   /* map */
                &vmaddr,                                /* address */
                a_out->a_text,                          /* size */
                VM_PROT_READ | VM_PROT_EXECUTE,         /* protection */
                VM_PROT_READ | VM_PROT_EXECUTE | VM_PROT_WRITE, /* max protection */
                MAP_FILE | MAP_PRIVATE | MAP_FIXED,     /* flags */
                iparams->vnodep,                        /* vnode */
                file_offset);                           /* offset */
        if (error)
                return (error);

        /*
         * Map data read/write (if text is 0, assume text is in data area
         *      [Bill's screwball mode])
         */
        vmaddr = virtual_offset + a_out->a_text;
        error =
            vm_mmap(&vmspace->vm_map,
                &vmaddr,
                a_out->a_data,
                VM_PROT_READ | VM_PROT_WRITE | (a_out->a_text ? 0 : VM_PROT_EXECUTE),
                VM_PROT_ALL, MAP_FILE | MAP_PRIVATE | MAP_FIXED, iparams->vnodep,
                file_offset + a_out->a_text);
        if (error)
                return (error);

        /*
         * Allocate demand-zeroed area for uninitialized data
         * "bss" = 'block started by symbol' - named after the IBM 7090
         *      instruction of the same name.
         */
        vmaddr = virtual_offset + a_out->a_text + a_out->a_data;
        error = vm_allocate(&vmspace->vm_map, &vmaddr, bss_size, FALSE);
        if (error)
                return (error);

        /* Fill in process VM information */
        vmspace->vm_tsize = a_out->a_text >> PAGE_SHIFT;
        vmspace->vm_dsize = (a_out->a_data + bss_size) >> PAGE_SHIFT;
        vmspace->vm_taddr = (caddr_t) virtual_offset;
        vmspace->vm_daddr = (caddr_t) virtual_offset + a_out->a_text;

        /* Fill in image_params */
        iparams->interpreted = 0;
        iparams->entry_addr = a_out->a_entry;

        return (0);
}

/*
 * Tell kern_execve.c about it, with a little help from the linker.
 * Since `const' objects end up in the text segment, TEXT_SET is the
 * correct directive to use.
 */
static const struct execsw aout_execsw = { exec_aout_imgact };
TEXT_SET(execsw_set, aout_execsw);