incorrect tracking of /proc/*/exe for overwritten running processes

["Mike Frysinger" <vapier.adi@gmail.com>]

looking at a simple program:
int main()
{
  if (fork()) return 0;
  printf("pid = %i\n", getpid());
  while (1) sleep(3600);
}

and where my / and /var/tmp are on the same partition:

# gcc test.c -o /usr/sbin/MOO
# /usr/sbin/MOO
pid = 17144
# readlink /proc/17144/exe
/usr/sbin/MOO

# gcc test.c -o /var/tmp/MOO
# mv /var/tmp/MOO /usr/sbin/MOO
# readlink /proc/17144/exe
/var/tmp/MOO (deleted)

i feel like the new exe link should actually read:
/usr/sbin/MOO (deleted)
otherwise people can easily get confused as they think their daemon
was started in /var/tmp/ and their machine was compromised

# uname -a
Linux vapier 2.6.21.3 #4 SMP PREEMPT Sat Jun 2 09:55:10 EDT 2007
x86_64 AMD Athlon(tm) 64 X2 Dual Core Processor 4200+ AuthenticAMD
GNU/Linux
-mike