root/kern/syscall/runprogram.c

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DEFINITIONS

This source file includes following definitions.
  1. runprogram

   1 /*
   2  * Copyright (c) 2000, 2001, 2002, 2003, 2004, 2005, 2008, 2009
   3  *      The President and Fellows of Harvard College.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  * 3. Neither the name of the University nor the names of its contributors
  14  *    may be used to endorse or promote products derived from this software
  15  *    without specific prior written permission.
  16  *
  17  * THIS SOFTWARE IS PROVIDED BY THE UNIVERSITY AND CONTRIBUTORS ``AS IS'' AND
  18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE UNIVERSITY OR CONTRIBUTORS BE LIABLE
  21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  27  * SUCH DAMAGE.
  28  */
  29 
  30 /*
  31  * Sample/test code for running a user program.  You can use this for
  32  * reference when implementing the execv() system call. Remember though
  33  * that execv() needs to do more than this function does.
  34  */
  35 
  36 #include <types.h>
  37 #include <kern/errno.h>
  38 #include <kern/fcntl.h>
  39 #include <lib.h>
  40 #include <proc.h>
  41 #include <current.h>
  42 #include <addrspace.h>
  43 #include <vm.h>
  44 #include <vfs.h>
  45 #include <syscall.h>
  46 #include <test.h>
  47 
  48 /*
  49  * Load program "progname" and start running it in usermode.
  50  * Does not return except on error.
  51  *
  52  * Calls vfs_open on progname and thus may destroy it.
  53  */
  54 int
  55 runprogram(char *progname)
  56 {
  57         struct addrspace *as;
  58         struct vnode *v;
  59         vaddr_t entrypoint, stackptr;
  60         int result;
  61 
  62         /* Open the file. */
  63         result = vfs_open(progname, O_RDONLY, 0, &v);
  64         if (result) {
  65                 return result;
  66         }
  67 
  68         /* We should be a new process. */
  69         KASSERT(curproc_getas() == NULL);
  70 
  71         /* Create a new address space. */
  72         as = as_create();
  73         if (as ==NULL) {
  74                 vfs_close(v);
  75                 return ENOMEM;
  76         }
  77 
  78         /* Switch to it and activate it. */
  79         curproc_setas(as);
  80         as_activate();
  81 
  82         /* Load the executable. */
  83         result = load_elf(v, &entrypoint);
  84         if (result) {
  85                 /* p_addrspace will go away when curproc is destroyed */
  86                 vfs_close(v);
  87                 return result;
  88         }
  89 
  90         /* Done with the file now. */
  91         vfs_close(v);
  92 
  93         /* Define the user stack in the address space */
  94         result = as_define_stack(as, &stackptr);
  95         if (result) {
  96                 /* p_addrspace will go away when curproc is destroyed */
  97                 return result;
  98         }
  99 
 100         /* Warp to user mode. */
 101         enter_new_process(0 /*argc*/, NULL /*userspace addr of argv*/,
 102                           stackptr, entrypoint);
 103         
 104         /* enter_new_process does not return. */
 105         panic("enter_new_process returned\n");
 106         return EINVAL;
 107 }
 108 

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