Changes in Makefile

9c6b7fbb - fortify: use if_changed_dep to record header dependency in *.cmd files

Sat, 27 Jul 2024 15:02:38 +0000

fortify: use if_changed_dep to record header dependency in *.cmd filesAfter building with CONFIG_FORTIFY_SOURCE=y, many .*.d files are leftin lib/test_fortify/ because the compiler outputs header dependenciesinto *.d without fixdep being invoked.When compiling C files, if_changed_dep should be used so that theauto-generated header dependencies are recorded in .*.cmd files.Currently, if_changed is incorrectly used, and only two headers arehard-coded in lib/Makefile.In the previous patch version, the kbuild test robot detected new errorson 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 solvedwhen we bump the minimal supported GCC version.Link: https://lore.kernel.org/oe-kbuild-all/CAK7LNARmJcyyzL-jVJfBPi3W684LTDmuhMf1koF0TXoCpKTmcw@mail.gmail.com/T/#m13771bf78ae21adff22efc4d310c973fb4bcaf67Signed-off-by: Masahiro Yamada Link: https://lore.kernel.org/r/20240727150302.1823750-4-masahiroy@kernel.orgSigned-off-by: Kees Cook List of files: /linux-6.15/lib/test_fortify/Makefile

5a8d0c46 - fortify: move test_fortify.sh to lib/test_fortify/

Sat, 27 Jul 2024 15:02:37 +0000

fortify: move test_fortify.sh to lib/test_fortify/This script is only used in lib/test_fortify/.There is no reason to keep it in scripts/.Signed-off-by: Masahiro Yamada Link: https://lore.kernel.org/r/20240727150302.1823750-3-masahiroy@kernel.orgSigned-off-by: Kees Cook List of files: /linux-6.15/lib/test_fortify/Makefile

4e9903b0 - fortify: refactor test_fortify Makefile to fix some build problems

Sat, 27 Jul 2024 15:02:36 +0000

fortify: refactor test_fortify Makefile to fix some build problemsThere are some issues in the test_fortify Makefile code.Problem 1: cc-disable-warning invokes compiler dozens of timesTo see how many times the cc-disable-warning is evaluated, changethis code: $(call cc-disable-warning,fortify-source)to: $(call cc-disable-warning,$(shell touch /tmp/fortify-$$$$)fortify-source)Then, build the kernel with CONFIG_FORTIFY_SOURCE=y. You will see alarge number of '/tmp/fortify-' files created: $ ls -1 /tmp/fortify-* | wc 80 80 1600This means the compiler was invoked 80 times just for checking the-Wno-fortify-source flag support.$(call cc-disable-warning,fortify-source) should be added to a simplevariable instead of a recursive variable.Problem 2: do not recompile string.o when the test code is updatedThe test cases are independent of the kernel. However, when the testcode is updated, $(obj)/string.o is rebuilt and vmlinux is relinkeddue to this dependency: $(obj)/string.o: $(obj)/$(TEST_FORTIFY_LOG)always-y is suitable for building the log files.Problem 3: redundant code clean-files += $(addsuffix .o, $(TEST_FORTIFY_LOGS))... is unneeded because the top Makefile globally cleans *.o files.This commit fixes these issues and makes the code readable.Signed-off-by: Masahiro Yamada Link: https://lore.kernel.org/r/20240727150302.1823750-2-masahiroy@kernel.orgSigned-off-by: Kees Cook List of files: /linux-6.15/lib/test_fortify/Makefile