Certain "programming errors" in the msync system call for FreeBSD 5.2.1 and earlier, and 4.10 and earlier, do not properly handle the MS_IN…

Certain "programming errors" in the msync system call for FreeBSD 5.2.1 and earlier, and 4.10 and earlier, do not properly handle the MS_INVALIDATE operation, which leads to cache consistency problems that allow a local user to prevent certain changes to files from being committed to disk.