0659df6fad
This prevents a situation where other thread modifies map entries permissions between setting max_prot, then relocking, then setting prot, confusing the operation outcome. E.g. you can get an error that is not possible if operation is performed atomic. Also enable setting rwx for max_prot even if map does not allow to set effective rwx protection. Reviewed by: brooks, markj (previous version) Sponsored by: The FreeBSD Foundation Differential Revision: https://reviews.freebsd.org/D28117
232 lines
6.5 KiB
C
232 lines
6.5 KiB
C
/*-
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* SPDX-License-Identifier: BSD-2-Clause-FreeBSD
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*
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* Copyright (c) 1994-1996 Søren Schmidt
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* All rights reserved.
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*
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* Based heavily on /sys/kern/imgact_aout.c which is:
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* Copyright (c) 1993, David Greenman
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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*
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* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*/
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#include <sys/cdefs.h>
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__FBSDID("$FreeBSD$");
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#include <sys/param.h>
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#include <sys/systm.h>
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#include <sys/exec.h>
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#include <sys/imgact.h>
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#include <sys/imgact_aout.h>
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#include <sys/kernel.h>
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#include <sys/lock.h>
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#include <sys/mman.h>
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#include <sys/mutex.h>
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#include <sys/proc.h>
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#include <sys/racct.h>
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#include <sys/resourcevar.h>
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#include <sys/vnode.h>
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#include <vm/vm.h>
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#include <vm/vm_kern.h>
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#include <vm/vm_param.h>
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#include <vm/pmap.h>
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#include <vm/vm_map.h>
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#include <vm/vm_extern.h>
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#include <i386/linux/linux.h>
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static int exec_linux_imgact(struct image_params *iparams);
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static int
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exec_linux_imgact(struct image_params *imgp)
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{
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const struct exec *a_out = (const struct exec *) imgp->image_header;
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struct vmspace *vmspace;
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vm_offset_t vmaddr;
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unsigned long virtual_offset, file_offset;
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unsigned long bss_size;
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ssize_t aresid;
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int error;
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if (((a_out->a_magic >> 16) & 0xff) != 0x64)
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return (-1);
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/*
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* Set file/virtual offset based on a.out variant.
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*/
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switch ((int)(a_out->a_magic & 0xffff)) {
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case 0413:
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virtual_offset = 0;
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file_offset = 1024;
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break;
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case 0314:
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virtual_offset = 4096;
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file_offset = 0;
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break;
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default:
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return (-1);
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}
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bss_size = round_page(a_out->a_bss);
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#ifdef DEBUG
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printf("imgact: text: %08lx, data: %08lx, bss: %08lx\n",
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(u_long)a_out->a_text, (u_long)a_out->a_data, bss_size);
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#endif
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/*
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* Check various fields in header for validity/bounds.
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*/
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if (a_out->a_entry < virtual_offset ||
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a_out->a_entry >= virtual_offset + a_out->a_text ||
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a_out->a_text & PAGE_MASK || a_out->a_data & PAGE_MASK)
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return (-1);
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/* text + data can't exceed file size */
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if (a_out->a_data + a_out->a_text > imgp->attr->va_size)
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return (EFAULT);
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/*
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* text/data/bss must not exceed limits
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*/
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PROC_LOCK(imgp->proc);
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if (a_out->a_text > maxtsiz ||
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a_out->a_data + bss_size > lim_cur_proc(imgp->proc, RLIMIT_DATA) ||
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racct_set(imgp->proc, RACCT_DATA, a_out->a_data + bss_size) != 0) {
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PROC_UNLOCK(imgp->proc);
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return (ENOMEM);
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}
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PROC_UNLOCK(imgp->proc);
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VOP_UNLOCK(imgp->vp);
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/*
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* Destroy old process VM and create a new one (with a new stack)
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*/
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error = exec_new_vmspace(imgp, &linux_sysvec);
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if (error)
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goto fail;
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vmspace = imgp->proc->p_vmspace;
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/*
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* Check if file_offset page aligned,.
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* Currently we cannot handle misaligned file offsets,
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* and so we read in the entire image (what a waste).
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*/
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if (file_offset & PAGE_MASK) {
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#ifdef DEBUG
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printf("imgact: Non page aligned binary %lu\n", file_offset);
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#endif
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/*
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* Map text+data+bss read/write/execute
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*/
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vmaddr = virtual_offset;
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error = vm_map_find(&vmspace->vm_map, NULL, 0, &vmaddr,
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a_out->a_text + a_out->a_data + bss_size, 0, VMFS_NO_SPACE,
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VM_PROT_ALL, VM_PROT_ALL, 0);
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if (error)
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goto fail;
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error = vn_rdwr(UIO_READ, imgp->vp, (void *)vmaddr, file_offset,
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a_out->a_text + a_out->a_data, UIO_USERSPACE, 0,
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curthread->td_ucred, NOCRED, &aresid, curthread);
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if (error != 0)
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goto fail;
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if (aresid != 0) {
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error = ENOEXEC;
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goto fail;
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}
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/*
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* remove write enable on the 'text' part
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*/
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error = vm_map_protect(&vmspace->vm_map, vmaddr,
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vmaddr + a_out->a_text, 0, VM_PROT_EXECUTE | VM_PROT_READ,
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VM_MAP_PROTECT_SET_MAXPROT);
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if (error)
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goto fail;
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} else {
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#ifdef DEBUG
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printf("imgact: Page aligned binary %lu\n", file_offset);
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#endif
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/*
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* Map text+data read/execute
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*/
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vmaddr = virtual_offset;
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error = vm_mmap(&vmspace->vm_map, &vmaddr,
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a_out->a_text + a_out->a_data,
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VM_PROT_READ | VM_PROT_EXECUTE, VM_PROT_ALL,
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MAP_PRIVATE | MAP_FIXED, OBJT_VNODE, imgp->vp, file_offset);
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if (error)
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goto fail;
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#ifdef DEBUG
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printf("imgact: startaddr=%08lx, length=%08lx\n",
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(u_long)vmaddr,
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(u_long)a_out->a_text + (u_long)a_out->a_data);
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#endif
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/*
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* allow read/write of data
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*/
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error = vm_map_protect(&vmspace->vm_map, vmaddr + a_out->a_text,
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vmaddr + a_out->a_text + a_out->a_data, VM_PROT_ALL, 0,
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VM_MAP_PROTECT_SET_PROT);
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if (error)
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goto fail;
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/*
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* Allocate anon demand-zeroed area for uninitialized data
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*/
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if (bss_size != 0) {
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vmaddr = virtual_offset + a_out->a_text + a_out->a_data;
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error = vm_map_find(&vmspace->vm_map, NULL, 0, &vmaddr,
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bss_size, 0, VMFS_NO_SPACE, VM_PROT_ALL, VM_PROT_ALL, 0);
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if (error)
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goto fail;
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#ifdef DEBUG
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printf("imgact: bssaddr=%08lx, length=%08lx\n", (u_long)vmaddr,
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bss_size);
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#endif
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}
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}
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/* Fill in process VM information */
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vmspace->vm_tsize = round_page(a_out->a_text) >> PAGE_SHIFT;
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vmspace->vm_dsize = round_page(a_out->a_data + bss_size) >> PAGE_SHIFT;
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vmspace->vm_taddr = (caddr_t)(void *)(uintptr_t)virtual_offset;
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vmspace->vm_daddr =
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(caddr_t)(void *)(uintptr_t)(virtual_offset + a_out->a_text);
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/* Fill in image_params */
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imgp->interpreted = 0;
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imgp->entry_addr = a_out->a_entry;
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imgp->proc->p_sysent = &linux_sysvec;
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fail:
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vn_lock(imgp->vp, LK_EXCLUSIVE | LK_RETRY);
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return (error);
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}
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/*
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* Tell kern_execve.c about it, with a little help from the linker.
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*/
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static struct execsw linux_execsw = { exec_linux_imgact, "Linux a.out" };
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EXEC_SET(linuxaout, linux_execsw);
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