1#include <sys/types.h>
2#include <dlfcn.h>
3#include <error.h>
4#include <mcheck.h>
5#include <stdlib.h>
6#include <unistd.h>
7
8pid_t pid, pid2;
9
10pid_t getpid(void)
11{
12 pid_t (*f)(void);
13 f = (pid_t (*)(void)) dlsym (RTLD_NEXT, name: "getpid");
14 if (f == NULL)
15 error (EXIT_FAILURE, errnum: 0, format: "dlsym (RTLD_NEXT, \"getpid\"): %s", dlerror ());
16 return (pid2 = f()) + 26;
17}
18
19int
20main (void)
21{
22 pid_t (*f)(void);
23
24 mtrace ();
25
26 f = (pid_t (*)(void)) dlsym (RTLD_DEFAULT, name: "getpid");
27 if (f == NULL)
28 error (EXIT_FAILURE, errnum: 0, format: "dlsym (RTLD_DEFAULT, \"getpid\"): %s", dlerror ());
29 pid = f();
30 if (pid != pid2 + 26)
31 error (EXIT_FAILURE, errnum: 0, format: "main getpid() not called");
32 return 0;
33}
34

source code of glibc/elf/restest2.c