$Config{ivsize}. For portability, be sure to mask off the excess bits
in the result of unary C<~>, e.g., C<~$x & 0xffffffff>.
+=head2 The passwd and shell returned by the getpwxxx() are now tainted
+
+Because the user can affect her own encrypted password and login shell
+the password and shell returned by the getpwent(), getpwnam(), and
+getpwuid() functions are tainted.
+
+=head2 The shmread() now taints its variable
+
+Because other (untrusted) processes can modify shared memory segments
+for their own nefarious purposes, the variable modified by shmread()
+becomes tainted.
+
=back
=head2 C Source Incompatibilities