memcheck/tests/linux/proc-auxv.c

   1 #include <elf.h>
   2 #include <link.h>
   3 #include <stdio.h>
   4 #include <stddef.h>
   5 #include <string.h>
   6 #include <sys/types.h>
   7 #include <sys/stat.h>
   8 #include <fcntl.h>
   9 #include <unistd.h>
  10 #include <stdlib.h>
  11
  12 int
  13 main (int argc, char **argv, char **envp)
  14 {
  15   ElfW(auxv_t) auxv;
  16   ElfW(auxv_t) *auxv_p;
  17
  18   void *entry0 = NULL;
  19   void *entry1 = NULL;
  20
  21   char *platform0 = NULL;
  22   char *platform1 = NULL;
  23
  24   // First try the "traditional" way.
  25   while (*envp++ != NULL)
  26     ; /* Skip, skip, skip... and after finding a NULL we have the auxv. */
  27
  28   for (auxv_p = (ElfW(auxv_t) *) envp;
  29        auxv_p->a_type != AT_NULL;
  30        auxv_p++)
  31     {
  32       if (auxv_p->a_type == AT_ENTRY)
  33         entry0 = (void *) auxv_p->a_un.a_val;
  34       if (auxv_p->a_type == AT_PLATFORM)
  35         platform0 = strdup((char *) auxv_p->a_un.a_val);
  36     }
  37
  38   // Now the /proc way as often used in libraries.
  39   int fd = open("/proc/self/auxv", O_RDONLY);
  40   if (fd == -1)
  41     return -1;
  42
  43   while (read(fd, &auxv, sizeof(auxv)) == sizeof(auxv))
  44     {
  45       if (auxv.a_type == AT_ENTRY)
  46         entry1 = (void *) auxv.a_un.a_val;
  47       if (auxv.a_type == AT_PLATFORM)
  48         platform1 = strdup((char *) auxv.a_un.a_val);
  49     }
  50   close(fd);
  51
  52   if (entry0 == entry1 && entry0 != NULL)
  53     fprintf(stderr, "entries OK\n");
  54
  55   if (strcmp (platform0, platform1) == 0)
  56     fprintf(stderr, "platform OK\n");
  57
  58   free (platform0);
  59   free (platform1);
  60
  61   return 0;
  62 }