procfs difference between NetBSD and Linux

[Mark Davies]

The below program demonstrates a difference between /proc on NetBSD and 
Linux.

If run in a directory with a writable "foo.txt" then on Linux the second 
openat() succeeds but on NetBSD it fails (EEXIST).  This behavior 
difference breaks the latest samba (4.14.x) on NetBSD.

Can this be fixed?

cheers
mark

---
#include <fcntl.h>
#include <stdio.h>
#include <limits.h>
#include <unistd.h>

int main ()
{
  int fd, new_fd;
  char buf[PATH_MAX];

  fd = openat (AT_FDCWD, "foo.txt",  O_RDONLY|O_NOFOLLOW);
  printf ("fd = %d\n", fd);
  sprintf(buf, "/proc/self/fd/%d", fd);
  sleep(10);
  new_fd = openat(AT_FDCWD, buf, O_RDWR|O_CREAT|O_NONBLOCK, 0744);
  printf ("new_fd = %d\n", new_fd);
  sleep (20);
}