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5856e12e69
fork. (On my machine, fork is about 240usecs, vfork is 78usecs.) Implement rfork(!RFPROC !RFMEM), which allows a thread to divorce its memory from the other threads of a group. Implement rfork(!RFPROC RFCFDG), which closes all file descriptors, eliminating possible existing shares with other threads/processes. Implement rfork(!RFPROC RFFDG), which divorces the file descriptors for a thread from the rest of the group. Fix the case where a thread does an exec. It is almost nonsense for a thread to modify the other threads address space by an exec, so we now automatically divorce the address space before modifying it.
216 lines
6.0 KiB
C
216 lines
6.0 KiB
C
/*
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* Copyright (c) 1993, David Greenman
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* All rights reserved.
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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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* $Id: imgact_aout.c,v 1.33 1997/02/22 09:38:55 peter Exp $
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*/
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#include "opt_rlimit.h"
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#include <sys/param.h>
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#include <sys/systm.h>
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#include <sys/resourcevar.h>
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#include <sys/exec.h>
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#include <sys/mman.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/proc.h>
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#include <sys/sysent.h>
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#include <sys/vnode.h>
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#include <vm/vm.h>
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#include <vm/vm_param.h>
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#include <vm/vm_prot.h>
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#include <sys/lock.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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static int exec_aout_imgact __P((struct image_params *imgp));
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static int
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exec_aout_imgact(imgp)
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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;
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unsigned long file_offset;
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unsigned long bss_size;
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int error;
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/*
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* Linux and *BSD binaries look very much alike,
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* only the machine id is different:
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* 0x64 for Linux, 0x86 for *BSD, 0x00 for BSDI.
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* NetBSD is in network byte order.. ugh.
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*/
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if (((a_out->a_magic >> 16) & 0xff) != 0x86 &&
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((a_out->a_magic >> 16) & 0xff) != 0 &&
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((((int)ntohl(a_out->a_magic)) >> 16) & 0xff) != 0x86)
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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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* We do two cases: host byte order and network byte order
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* (for NetBSD compatibility)
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*/
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switch ((int)(a_out->a_magic & 0xffff)) {
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case ZMAGIC:
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virtual_offset = 0;
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if (a_out->a_text) {
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file_offset = PAGE_SIZE;
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} else {
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/* Bill's "screwball mode" */
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file_offset = 0;
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}
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break;
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case QMAGIC:
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virtual_offset = PAGE_SIZE;
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file_offset = 0;
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break;
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default:
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/* NetBSD compatibility */
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switch ((int)(ntohl(a_out->a_magic) & 0xffff)) {
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case ZMAGIC:
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case QMAGIC:
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virtual_offset = PAGE_SIZE;
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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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}
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bss_size = roundup(a_out->a_bss, PAGE_SIZE);
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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 (/* entry point must lay with text region */
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a_out->a_entry < virtual_offset ||
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a_out->a_entry >= virtual_offset + a_out->a_text ||
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/* text and data size must each be page rounded */
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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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if (/* text can't exceed maximum text size */
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a_out->a_text > MAXTSIZ ||
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/* data + bss can't exceed maximum data size */
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a_out->a_data + bss_size > MAXDSIZ ||
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/* data + bss can't exceed rlimit */
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a_out->a_data + bss_size >
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imgp->proc->p_rlimit[RLIMIT_DATA].rlim_cur)
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return (ENOMEM);
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/* copy in arguments and/or environment from old process */
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error = exec_extract_strings(imgp);
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if (error)
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return (error);
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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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exec_new_vmspace(imgp);
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/*
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* The vm space can be changed by exec_new_vmspace
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*/
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vmspace = imgp->proc->p_vmspace;
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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 =
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vm_mmap(&vmspace->vm_map, /* map */
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&vmaddr, /* address */
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a_out->a_text + a_out->a_data, /* size */
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VM_PROT_READ | VM_PROT_EXECUTE, /* protection */
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VM_PROT_ALL, /* max protection */
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MAP_PRIVATE | MAP_FIXED, /* flags */
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(caddr_t)imgp->vp, /* vnode */
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file_offset); /* offset */
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if (error)
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return (error);
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/*
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* allow writing of data
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*/
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vm_map_protect(&vmspace->vm_map,
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vmaddr + a_out->a_text,
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vmaddr + a_out->a_text + a_out->a_data,
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VM_PROT_ALL,
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FALSE);
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if (bss_size != 0) {
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/*
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* Allocate demand-zeroed area for uninitialized data
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* "bss" = 'block started by symbol' - named after the IBM 7090
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* instruction of the same name.
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*/
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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, bss_size, FALSE, VM_PROT_ALL, VM_PROT_ALL, 0);
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if (error)
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return (error);
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}
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/* Fill in process VM information */
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vmspace->vm_tsize = a_out->a_text >> PAGE_SHIFT;
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vmspace->vm_dsize = (a_out->a_data + bss_size) >> PAGE_SHIFT;
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vmspace->vm_taddr = (caddr_t) virtual_offset;
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vmspace->vm_daddr = (caddr_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 = &aout_sysvec;
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/* Indicate that this file should not be modified */
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imgp->vp->v_flag |= VTEXT;
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return (0);
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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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* Since `const' objects end up in the text segment, TEXT_SET is the
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* correct directive to use.
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*/
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static const struct execsw aout_execsw = { exec_aout_imgact, "a.out" };
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TEXT_SET(execsw_set, aout_execsw);
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