freebsd-dev/sys/i386/linux/imgact_linux.c
John Dyson 5856e12e69 Fully implement vfork. Vfork is now much much faster than even our
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.
1997-04-13 01:48:35 +00:00

243 lines
7.0 KiB
C

/*-
* Copyright (c) 1994-1996 Søren Schmidt
* All rights reserved.
*
* Based heavily on /sys/kern/imgact_aout.c which is:
* Copyright (c) 1993, David Greenman
*
* 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
* in this position and unchanged.
* 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. The name of the author may not be used to endorse or promote products
* derived from this software withough specific prior written permission
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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_linux.c,v 1.21 1997/04/01 08:39:05 bde Exp $
*/
#ifndef LKM
#include "opt_rlimit.h"
#endif
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/resourcevar.h>
#include <sys/exec.h>
#include <sys/mman.h>
#include <sys/imgact.h>
#include <sys/imgact_aout.h>
#include <sys/kernel.h>
#include <sys/proc.h>
#include <sys/sysent.h>
#include <sys/vnode.h>
#include <vm/vm.h>
#include <vm/vm_kern.h>
#include <vm/vm_param.h>
#include <vm/pmap.h>
#include <vm/vm_map.h>
#include <vm/vm_prot.h>
#include <vm/vm_extern.h>
#include <i386/linux/linux.h>
#include <i386/linux/linux_proto.h>
extern int exec_linux_imgact __P((struct image_params *iparams));
int
exec_linux_imgact(imgp)
struct image_params *imgp;
{
const struct exec *a_out = (const struct exec *) imgp->image_header;
struct vmspace *vmspace;
vm_offset_t vmaddr;
unsigned long virtual_offset, file_offset;
vm_offset_t buffer;
unsigned long bss_size;
int error;
if (((a_out->a_magic >> 16) & 0xff) != 0x64)
return -1;
/*
* Set file/virtual offset based on a.out variant.
*/
switch ((int)(a_out->a_magic & 0xffff)) {
case 0413:
virtual_offset = 0;
file_offset = 1024;
break;
case 0314:
virtual_offset = 4096;
file_offset = 0;
break;
default:
return (-1);
}
bss_size = round_page(a_out->a_bss);
#ifdef DEBUG
printf("imgact: text: %08x, data: %08x, bss: %08x\n", a_out->a_text, a_out->a_data, bss_size);
#endif
/*
* Check various fields in header for validity/bounds.
*/
if (a_out->a_entry < virtual_offset ||
a_out->a_entry >= virtual_offset + a_out->a_text ||
a_out->a_text & PAGE_MASK || a_out->a_data & PAGE_MASK)
return (-1);
/* text + data can't exceed file size */
if (a_out->a_data + a_out->a_text > imgp->attr->va_size)
return (EFAULT);
/*
* text/data/bss must not exceed limits
*/
if (a_out->a_text > MAXTSIZ || a_out->a_data + bss_size > MAXDSIZ ||
a_out->a_data+bss_size > imgp->proc->p_rlimit[RLIMIT_DATA].rlim_cur)
return (ENOMEM);
/* copy in arguments and/or environment from old process */
error = exec_extract_strings(imgp);
if (error)
return (error);
/*
* Destroy old process VM and create a new one (with a new stack)
*/
exec_new_vmspace(imgp);
vmspace = imgp->proc->p_vmspace;
/*
* Check if file_offset page aligned,.
* Currently we cannot handle misalinged file offsets,
* and so we read in the entire image (what a waste).
*/
if (file_offset & PAGE_MASK) {
#ifdef DEBUG
printf("imgact: Non page aligned binary %d\n", file_offset);
#endif
/*
* Map text+data+bss read/write/execute
*/
vmaddr = virtual_offset;
error = vm_map_find(&vmspace->vm_map, NULL, 0, &vmaddr,
a_out->a_text + a_out->a_data + bss_size, FALSE,
VM_PROT_ALL, VM_PROT_ALL, 0);
if (error)
return error;
error = vm_mmap(kernel_map, &buffer,
round_page(a_out->a_text + a_out->a_data + file_offset),
VM_PROT_READ, VM_PROT_READ, 0,
(caddr_t) imgp->vp, trunc_page(file_offset));
if (error)
return error;
error = copyout((caddr_t)(buffer + file_offset), (caddr_t)vmaddr,
a_out->a_text + a_out->a_data);
vm_map_remove(kernel_map, buffer,
buffer + round_page(a_out->a_text + a_out->a_data + file_offset));
if (error)
return error;
/*
* remove write enable on the 'text' part
*/
error = vm_map_protect(&vmspace->vm_map,
vmaddr,
vmaddr + a_out->a_text,
VM_PROT_EXECUTE|VM_PROT_READ,
TRUE);
if (error)
return error;
}
else {
#ifdef DEBUG
printf("imgact: Page aligned binary %d\n", file_offset);
#endif
/*
* Map text+data read/execute
*/
vmaddr = virtual_offset;
error = vm_mmap(&vmspace->vm_map, &vmaddr,
a_out->a_text + a_out->a_data,
VM_PROT_READ | VM_PROT_EXECUTE,
VM_PROT_ALL,
MAP_PRIVATE | MAP_FIXED,
(caddr_t)imgp->vp, file_offset);
if (error)
return (error);
#ifdef DEBUG
printf("imgact: startaddr=%08x, length=%08x\n", vmaddr, a_out->a_text + a_out->a_data);
#endif
/*
* allow read/write of data
*/
error = vm_map_protect(&vmspace->vm_map,
vmaddr + a_out->a_text,
vmaddr + a_out->a_text + a_out->a_data,
VM_PROT_ALL,
FALSE);
if (error)
return (error);
/*
* Allocate anon demand-zeroed area for uninitialized data
*/
if (bss_size != 0) {
vmaddr = virtual_offset + a_out->a_text + a_out->a_data;
error = vm_map_find(&vmspace->vm_map, NULL, 0, &vmaddr,
bss_size, FALSE, VM_PROT_ALL, VM_PROT_ALL, 0);
if (error)
return (error);
#ifdef DEBUG
printf("imgact: bssaddr=%08x, length=%08x\n", vmaddr, bss_size);
#endif
}
/* Indicate that this file should not be modified */
imgp->vp->v_flag |= VTEXT;
}
/* Fill in process VM information */
vmspace->vm_tsize = round_page(a_out->a_text) >> PAGE_SHIFT;
vmspace->vm_dsize = round_page(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 */
imgp->interpreted = 0;
imgp->entry_addr = a_out->a_entry;
imgp->proc->p_sysent = &linux_sysvec;
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.
*/
const struct execsw linux_execsw = { exec_linux_imgact, "linux a.out" };
TEXT_SET(execsw_set, linux_execsw);