tests/vm_spawn_tool.c

   1 #include <stdio.h>
   2 #include <unistd.h>
   3 #include <spawn.h>
   4 #include <spawn_private.h>
   5 #include <sys/sysctl.h>
   6
   7 extern char **environ;
   8
   9 #ifndef _POSIX_SPAWN_FORCE_4K_PAGES
  10 #define _POSIX_SPAWN_FORCE_4K_PAGES 0x1000
  11 #endif /* _POSIX_SPAWN_FORCE_4K_PAGES */
  12
  13 int
  14 main(int argc, char *argv[])
  15 {
  16         if (argc < 2) {
  17                 fprintf(stderr, "Usage: %s </path/to/command> [<arg> ..]\n", argv[0]);
  18                 return 1;
  19         }
  20
  21         char * prog_path = argv[1];
  22         if (0 != access(prog_path, X_OK)) {
  23                 fprintf(stderr, "%s is not an executable\n", prog_path);
  24                 return 1;
  25         }
  26
  27         pid_t newpid = 0;
  28         posix_spawn_file_actions_t fileactions;
  29         posix_spawnattr_t spawnattrs;
  30         if (posix_spawnattr_init(&spawnattrs)) {
  31                 perror("posix_spawnattr_init");
  32                 return 1;
  33         }
  34         if (posix_spawn_file_actions_init(&fileactions)) {
  35                 perror("posix_spawn_file_actions_init");
  36                 return 1;
  37         }
  38         short sp_flags = POSIX_SPAWN_SETEXEC;
  39
  40         /* Need to set special flags */
  41         int supported = 0;
  42         size_t supported_size = sizeof(supported);
  43
  44         int r = sysctlbyname("debug.vm_mixed_pagesize_supported", &supported, &supported_size, NULL, 0);
  45         if (r == 0 && supported) {
  46                 sp_flags |= _POSIX_SPAWN_FORCE_4K_PAGES;
  47         } else {
  48                 /*
  49                  * We didnt find debug.vm.mixed_page.supported OR its set to 0.
  50                  * Skip the test.
  51                  */
  52                 printf("Hardware doesn't support 4K pages, skipping test...");
  53                 return 0;
  54         }
  55
  56         posix_spawnattr_setflags(&spawnattrs, sp_flags);
  57         posix_spawn(&newpid, prog_path, &fileactions, &spawnattrs, &argv[1], environ);
  58
  59         /* Should not have reached here */
  60         fprintf(stderr, "should not have reached here");
  61         return 1;
  62 }