The problem isn't that it relies on developer foresight to make the second call to set_fs. The problem (if you look through other LWN articles on the subject) i

The problem isn't that it relies on developer foresight to make the second call to set_fs. The problem (if you look through other LWN articles on the subject) is that the set_fs calls can be prone to not getting restored if the kernel code is interrupted.