i386/junos/MIT/course/src/src.lab/user/testpteshare.c

   1 #include <inc/x86.h>
   2 #include <inc/lib.h>
   3
   4 #define VA      ((char *) 0xA0000000)
   5 const char *msg = "hello, world\n";
   6 const char *msg2 = "goodbye, world\n";
   7
   8 void childofspawn(void);
   9
  10 void
  11 umain(int argc, char **argv)
  12 {
  13         int r;
  14
  15         if (argc != 0)
  16                 childofspawn();
  17
  18         if ((r = sys_page_alloc(0, VA, PTE_P|PTE_W|PTE_U|PTE_SHARE)) < 0)
  19                 panic("sys_page_alloc: %e", r);
  20
  21         // check fork
  22         if ((r = fork()) < 0)
  23                 panic("fork: %e", r);
  24         if (r == 0) {
  25                 strcpy(VA, msg);
  26                 exit();
  27         }
  28         wait(r);
  29         cprintf("fork handles PTE_SHARE %s\n", strcmp(VA, msg) == 0 ? "right" : "wrong");
  30
  31         // check spawn
  32         if ((r = spawnl("/testpteshare", "testpteshare", "arg", 0)) < 0)
  33                 panic("spawn: %e", r);
  34         wait(r);
  35         cprintf("spawn handles PTE_SHARE %s\n", strcmp(VA, msg2) == 0 ? "right" : "wrong");
  36
  37         breakpoint();
  38 }
  39
  40 void
  41 childofspawn(void)
  42 {
  43         strcpy(VA, msg2);
  44         exit();
  45 }