vdso.c

#include <sys/auxv.h>
#include <stdio.h>

/* Write vdso segment to a file for post inspection by objdump. */
int main(int argc, char* argv[], char** envp) {
  FILE* fp = fopen("foo.vdso", "w+");
 
 /* Fetch pointer to start of vdso section. */
  void* p = (void*)getauxval(AT_SYSINFO_EHDR);
  
  /* On my system vdso appears to use two pages when inspecting a couple
     of running programs /proc/<pid>/maps files. */
  fwrite(p, 2*4096, 1, fp);
  fclose(fp);
  return 0;
}