apps/init/proc.c

   1 /*
   2     meinOS - A unix-like x86 microkernel operating system
   3     Copyright (C) 2008  Janosch Gräf <janosch.graef@gmx.net>
   4
   5     This program is free software: you can redistribute it and/or modify
   6     it under the terms of the GNU General Public License as published by
   7     the Free Software Foundation, either version 3 of the License, or
   8     (at your option) any later version.
   9
  10     This program is distributed in the hope that it will be useful,
  11     but WITHOUT ANY WARRANTY; without even the implied warranty of
  12     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13     GNU General Public License for more details.
  14
  15     You should have received a copy of the GNU General Public License
  16     along with this program.  If not, see <http://www.gnu.org/licenses/>.
  17 */
  18
  19 #include <libgen.h>
  20 #include <sys/types.h>
  21 #include <proc.h>
  22 #include <stdlib.h>
  23 #include <rpc.h>
  24 #include <misc.h>
  25 #include <errno.h>
  26
  27 #include "init.h"
  28
  29 pid_t proc_fork(void *child_entry) {
  30   // Create process
  31   char *name = getname(rpc_curpid);
  32   pid_t pid = proc_create(name,getuidbypid(rpc_curpid),getgidbypid(rpc_curpid),rpc_curpid);
  33
  34   if (pid!=-1) {
  35     // Copy userspace memory
  36     size_t num_pages,i;
  37     void **pages = proc_mempagelist(rpc_curpid,&num_pages);
  38
  39     if (pages!=NULL) {
  40       for (i=0;i<num_pages;i++) {
  41         int writable,swappable;
  42         void *srcp = proc_memget(rpc_curpid,pages[i],NULL,&writable,&swappable,NULL);
  43
  44         if (srcp!=NULL) {
  45           // Map parent's page to init
  46           void *srcv = proc_memmap(1,NULL,srcp,0,0,0);
  47
  48           // Allocate child's page in init's addrspace
  49           void *dstv = proc_memmap(1,NULL,NULL,1,0,0);
  50           void *dstp = mem_getphysaddr(dstv);
  51
  52           // Map child's page to child
  53           proc_memmap(pid,pages[i],dstp,writable,swappable,0);
  54
  55           // Copy
  56           memcpy(dstv,srcv,PAGE_SIZE);
  57
  58           proc_memunmap(1,srcv);
  59           proc_memunmap(1,dstv);
  60         }
  61         else proc_memmap(pid,pages[i],NULL,writable,swappable,0);
  62       }
  63     }
  64
  65     // Set stack (we already created one by copying address space)
  66     int *stack = proc_getstack(rpc_curpid);
  67     proc_setstack(pid,stack);
  68
  69     // Set entrypoint of child
  70     proc_jump(pid,child_entry);
  71   }
  72
  73   return pid;
  74 }
  75
  76 int proc_exec(const char *file,int var) {
  77   // Change process
  78   char *_file = strdup(file);
  79   proc_setname(rpc_curpid,basename(_file));
  80   free(_file);
  81   proc_setvar(rpc_curpid,var);
  82
  83   // Load executable
  84   exe_t *exe = exe_create(file);
  85   if (exe!=NULL) {
  86     // Remove old addrspace
  87     size_t num_pages,i;
  88     void **pages = proc_mempagelist(rpc_curpid,&num_pages);
  89     if (pages!=NULL) {
  90       for (i=0;i<num_pages;i++) proc_memfree(rpc_curpid,pages[i]);
  91     }
  92
  93     void *entrypoint = exe_load(exe,rpc_curpid);
  94
  95     if (entrypoint!=NULL) {
  96       proc_createstack(rpc_curpid);
  97       proc_jump(rpc_curpid,entrypoint);
  98     }
  99     else {
 100       dbgmsg("failed loading executable!");
 101       dbgmsg("TODO: destroy process\n");
 102       while (1);
 103     }
 104
 105     exe_destroy(exe);
 106     return 0;
 107   }
 108   else return errno;
 109 }