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 } 63
