os161/kern/syscall/runprogram.c
2015-12-23 00:50:04 +00:00

110 lines
3.3 KiB
C

/*
* Copyright (c) 2000, 2001, 2002, 2003, 2004, 2005, 2008, 2009
* The President and Fellows of Harvard College.
*
* 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. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE UNIVERSITY 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 UNIVERSITY 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.
*/
/*
* Sample/test code for running a user program. You can use this for
* reference when implementing the execv() system call. Remember though
* that execv() needs to do more than runprogram() does.
*/
#include <types.h>
#include <kern/errno.h>
#include <kern/fcntl.h>
#include <lib.h>
#include <proc.h>
#include <current.h>
#include <addrspace.h>
#include <vm.h>
#include <vfs.h>
#include <syscall.h>
#include <test.h>
/*
* Load program "progname" and start running it in usermode.
* Does not return except on error.
*
* Calls vfs_open on progname and thus may destroy it.
*/
int
runprogram(char *progname)
{
struct addrspace *as;
struct vnode *v;
vaddr_t entrypoint, stackptr;
int result;
/* Open the file. */
result = vfs_open(progname, O_RDONLY, 0, &v);
if (result) {
return result;
}
/* We should be a new process. */
KASSERT(proc_getas() == NULL);
/* Create a new address space. */
as = as_create();
if (as == NULL) {
vfs_close(v);
return ENOMEM;
}
/* Switch to it and activate it. */
proc_setas(as);
as_activate();
/* Load the executable. */
result = load_elf(v, &entrypoint);
if (result) {
/* p_addrspace will go away when curproc is destroyed */
vfs_close(v);
return result;
}
/* Done with the file now. */
vfs_close(v);
/* Define the user stack in the address space */
result = as_define_stack(as, &stackptr);
if (result) {
/* p_addrspace will go away when curproc is destroyed */
return result;
}
/* Warp to user mode. */
enter_new_process(0 /*argc*/, NULL /*userspace addr of argv*/,
NULL /*userspace addr of environment*/,
stackptr, entrypoint);
/* enter_new_process does not return. */
panic("enter_new_process returned\n");
return EINVAL;
}