On Wed, Oct 18, 2023 at 03:25:19AM +0200, Jan Engelhardt wrote:

On Tuesday 2023-10-17 19:50, Lucas De Marchi wrote:

quoted

quoted

+AC_ARG_WITH([module_directory],
+        AS_HELP_STRING([--with-module-directory=DIR], [directory in which to
look for kernel modules - typically '/lib/modules' or
'${prefix}/lib/modules']),
+        [], [with_module_directory=/lib/modules])
+AC_SUBST([module_directory], [$with_module_directory])

we will probably have "fun" results if we accept a relative path here.

$ ./configure --prefix=/usr --bindir=../bin
configure: error: expected an absolute directory name for --bindir: ../bin

While such check does not exist for --with-module-directory, everyone
has likely been well-trained not to use relative paths. Even if, say,
cmake/meson *could* do it, it just would have never occurred to me to
actually *utilize* it, because it is just too ambiguous and
potentially dangerous.

Just think of all the fun you could have with LD_LIBRARY_PATH=".."

Is there an example of how this guarding against relative paths is done
in other options that accept directories?

There may be something for the built-in options but the existing custom
rootlibdir option does not seem to have anything either.

Thanks

Michal