After building with CONFIG_FORTIFY_SOURCE=y, many .*.d files are left
in lib/test_fortify/ because the compiler outputs header dependencies
into *.d without fixdep being invoked.
When compiling C files, if_changed_dep should be used so that the
auto-generated header dependencies are recorded in .*.cmd files.
Currently, if_changed is incorrectly used, and only two headers are
hard-coded in lib/Makefile.
In the previous patch version, the kbuild test robot detected new errors
on GCC 7.
GCC 7 or older does not produce test.d with the following test code:
$ echo 'void b(void) __attribute__((__error__(""))); void a(void) { b(); }' |
gcc -Wp,-MMD,test.d -c -o /dev/null -x c -
Perhaps, this was a bug that existed in older GCC versions.
Skip the tests for GCC<=7 for now, as this will be eventually solved
when we bump the minimal supported GCC version.
Link: https://lore.kernel.org/oe-kbuild-all/CAK7LNARmJcyyzL-jVJfBPi3W684LTDmuhMf1koF0TXoCpKTmcw@mail.gmail.com/T/#m13771bf78ae21adff22efc4d310c973fb4bcaf67
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Link: https://lore.kernel.org/r/20240727150302.1823750-4-masahiroy@kernel.org
Signed-off-by: Kees Cook <kees@kernel.org>