This may need more work to prevent warning messages during
"make cleandir" when the commands in "!=" assignments are executed
even though tools may not have been built.
- Use lstat instead of stat to find the destination path. we can make a symlink
to a broken symlink this way.
- When calling process to create a link, check if the source is a symlink
instead of trying to remove what the symlink points to!
- Don't create hard links to directories.
XXX: NB. Still sup is broken when used with the delete option. This is because
in the delete pass, it goes and tries to delete all files in the old list
that don't exist in the new list. This is a problem when a directory becomes
a symlink to a hierarchy that contains the same names. Then sup will cross
the symlink and start deleting files and directories from the destination.
This is not easily fixed. Don't use sup with symlink/rsymlink and the delete
option at the same time or *be careful*!
running, you can end up with an incomplete scan file because there was no
error checking done. Then sup will happily delete all the files that are
missing from the scan file. Make sure we have written a good scan file before
renaming.
FORTIFY_SOURCE feature of libssp, thus checking the size of arguments to
various string and memory copy and set functions (as well as a few system
calls and other miscellany) where known at function entry. RedHat has
evidently built all "core system packages" with this option for some time.
This option should be used at the top of Makefiles (or Makefile.inc where
this is used for subdirectories) but after any setting of LIB.
This is only useful for userland code, and cannot be used in libc or in
any code which includes the libc internals, because it overrides certain
libc functions with macros. Some effort has been made to make USE_FORT=yes
work correctly for a full-system build by having the bsd.sys.mk logic
disable the feature where it should not be used (libc, libssp iteself,
the kernel) but no attempt has been made to build the entire system with
USE_FORT and doing so will doubtless expose numerous bugs and misfeatures.
Adjust the system build so that all programs and libraries that are setuid,
directly handle network data (including serial comm data), perform
authentication, or appear likely to have (or have a history of having)
data-driven bugs (e.g. file(1)) are built with USE_FORT=yes by default,
with the exception of libc, which cannot use USE_FORT and thus uses
only USE_SSP by default. Tested on i386 with no ill results; USE_FORT=no
per-directory or in a system build will disable if desired.
