Re: [PATCH RESEND v4 1/3] kselftests: lib.mk: Add TEST_GEN_MODS_DIR variable

[Shuah Khan <skhan@linuxfoundation.org>]

On 1/2/24 15:31, Joe Lawrence wrote:
> On Wed, Dec 20, 2023 at 01:53:12PM -0300, Marcos Paulo de Souza wrote:
>> Add TEST_GEN_MODS_DIR variable for kselftests. It can point to
>> a directory containing kernel modules that will be used by
>> selftest scripts.
>>
>> The modules are built as external modules for the running kernel.
>> As a result they are always binary compatible and the same tests
>> can be used for older or newer kernels.
>>
>> The build requires "kernel-devel" package to be installed.
>> For example, in the upstream sources, the rpm devel package
>> is produced by "make rpm-pkg"
>>
>> The modules can be built independently by
>>
>>    make -C tools/testing/selftests/livepatch/
>>
>> or they will be automatically built before running the tests via
>>
>>    make -C tools/testing/selftests/livepatch/ run_tests
>>
>> Note that they are _not_ built when running the standalone
>> tests by calling, for example, ./test-state.sh.
>>
>> Signed-off-by: Marcos Paulo de Souza <mpdesouza@suse.com>
>> ---
>>   Documentation/dev-tools/kselftest.rst |  4 ++++
>>   tools/testing/selftests/lib.mk        | 20 +++++++++++++++-----
>>   2 files changed, 19 insertions(+), 5 deletions(-)
>>
>> diff --git a/Documentation/dev-tools/kselftest.rst b/Documentation/dev-tools/kselftest.rst
>> index ab376b316c36..7f3582a67318 100644
>> --- a/Documentation/dev-tools/kselftest.rst
>> +++ b/Documentation/dev-tools/kselftest.rst
>> @@ -245,6 +245,10 @@ Contributing new tests (details)
>>      TEST_PROGS, TEST_GEN_PROGS mean it is the executable tested by
>>      default.
>>   
>> +   TEST_GEN_MODS_DIR should be used by tests that require modules to be built
>> +   before the test starts. The variable will contain the name of the directory
>> +   containing the modules.
>> +
>>      TEST_CUSTOM_PROGS should be used by tests that require custom build
>>      rules and prevent common build rule use.
>>   
>> diff --git a/tools/testing/selftests/lib.mk b/tools/testing/selftests/lib.mk
>> index 118e0964bda9..6c7c5a0112cf 100644
>> --- a/tools/testing/selftests/lib.mk
>> +++ b/tools/testing/selftests/lib.mk
>> @@ -70,12 +70,15 @@ KHDR_INCLUDES := -isystem $(KHDR_DIR)
>>   # TEST_PROGS are for test shell scripts.
>>   # TEST_CUSTOM_PROGS and TEST_PROGS will be run by common run_tests
>>   # and install targets. Common clean doesn't touch them.
>> +# TEST_GEN_MODS_DIR is used to specify a directory with modules to be built
>> +# before the test executes. These modules are cleaned on the clean target as well.
>>   TEST_GEN_PROGS := $(patsubst %,$(OUTPUT)/%,$(TEST_GEN_PROGS))
>>   TEST_GEN_PROGS_EXTENDED := $(patsubst %,$(OUTPUT)/%,$(TEST_GEN_PROGS_EXTENDED))
>>   TEST_GEN_FILES := $(patsubst %,$(OUTPUT)/%,$(TEST_GEN_FILES))
>> +TEST_GEN_MODS_DIR := $(patsubst %,$(OUTPUT)/%,$(TEST_GEN_MODS_DIR))
>>   
>>   all: kernel_header_files $(TEST_GEN_PROGS) $(TEST_GEN_PROGS_EXTENDED) \
>> -     $(TEST_GEN_FILES)
>> +     $(TEST_GEN_FILES) $(if $(TEST_GEN_MODS_DIR),gen_mods_dir)
>>   
>>   kernel_header_files:
>>   	@ls $(KHDR_DIR)/linux/*.h >/dev/null 2>/dev/null;                      \
>> @@ -105,8 +108,8 @@ endef
>>   
>>   run_tests: all
>>   ifdef building_out_of_srctree
>> -	@if [ "X$(TEST_PROGS)$(TEST_PROGS_EXTENDED)$(TEST_FILES)" != "X" ]; then \
>> -		rsync -aq --copy-unsafe-links $(TEST_PROGS) $(TEST_PROGS_EXTENDED) $(TEST_FILES) $(OUTPUT); \
>> +	@if [ "X$(TEST_PROGS)$(TEST_PROGS_EXTENDED)$(TEST_FILES)$(TEST_GEN_MODS_DIR)" != "X" ]; then \
>> +		rsync -aq --copy-unsafe-links $(TEST_PROGS) $(TEST_PROGS_EXTENDED) $(TEST_FILES) $(TEST_GEN_MODS_DIR) $(OUTPUT); \
>>   	fi
>>   	@if [ "X$(TEST_PROGS)" != "X" ]; then \
>>   		$(call RUN_TESTS, $(TEST_GEN_PROGS) $(TEST_CUSTOM_PROGS) \
>> @@ -118,6 +121,12 @@ else
>>   	@$(call RUN_TESTS, $(TEST_GEN_PROGS) $(TEST_CUSTOM_PROGS) $(TEST_PROGS))
>>   endif
>>   
>> +gen_mods_dir:
>> +	$(Q)$(MAKE) -C $(TEST_GEN_MODS_DIR)
>> +
>> +clean_mods_dir:
>> +	$(Q)$(MAKE) -C $(TEST_GEN_MODS_DIR) clean
>> +
>>   define INSTALL_SINGLE_RULE
>>   	$(if $(INSTALL_LIST),@mkdir -p $(INSTALL_PATH))
>>   	$(if $(INSTALL_LIST),rsync -a --copy-unsafe-links $(INSTALL_LIST) $(INSTALL_PATH)/)
>> @@ -131,6 +140,7 @@ define INSTALL_RULE
>>   	$(eval INSTALL_LIST = $(TEST_CUSTOM_PROGS)) $(INSTALL_SINGLE_RULE)
>>   	$(eval INSTALL_LIST = $(TEST_GEN_PROGS_EXTENDED)) $(INSTALL_SINGLE_RULE)
>>   	$(eval INSTALL_LIST = $(TEST_GEN_FILES)) $(INSTALL_SINGLE_RULE)
>> +	$(eval INSTALL_LIST = $(TEST_GEN_MODS_DIR)) $(INSTALL_SINGLE_RULE)
> 
> Hi Marcos,
> 
> Sorry for the late reply on this, but I'm reviewing this version by
> trying to retrofit it into our selftest packaging (pre-build the test
> module .ko's and stash those into an rpm rather than building on the
> test host).
> 
> Since $TEST_GEN_MODS_DIR is treated as a directory, I found that the
> selftest install target copies a bunch of intermediate object and kbuild
> files:
> 
>    $ mkdir /tmp/test-install
>    $ make KDIR=$(pwd) INSTALL_PATH=/tmp/test-install TARGETS=livepatch \
>         -C tools/testing/selftests/ install
> 
>    [ ... builds livepatch selftests ... ]
> 
> the rsync in question:
> 
>    rsync -a --copy-unsafe-links /home/jolawren/src/kernel/tools/testing/selftests/livepatch/test_modules /tmp/test-install/livepatch/
>    ...
> 
> and then looking at the destination:
> 
>    $ tree -a /tmp/test-install/
>    /tmp/test-install/
>    ├── kselftest
>    │   ├── module.sh
>    │   ├── prefix.pl
>    │   └── runner.sh
>    ├── kselftest-list.txt
>    ├── livepatch
>    │   ├── config
>    │   ├── functions.sh
>    │   ├── settings
>    │   ├── test-callbacks.sh
>    │   ├── test-ftrace.sh
>    │   ├── test_klp-call_getpid
>    │   ├── test-livepatch.sh
>    │   ├── test_modules
>    │   │   ├── Makefile
>    │   │   ├── modules.order
>    │   │   ├── .modules.order.cmd
>    │   │   ├── Module.symvers
>    │   │   ├── .Module.symvers.cmd
>    │   │   ├── test_klp_atomic_replace.c
>    │   │   ├── test_klp_atomic_replace.ko
>    │   │   ├── .test_klp_atomic_replace.ko.cmd
>    │   │   ├── test_klp_atomic_replace.mod
>    │   │   ├── test_klp_atomic_replace.mod.c
>    │   │   ├── .test_klp_atomic_replace.mod.cmd
>    │   │   ├── test_klp_atomic_replace.mod.o
>    │   │   ├── .test_klp_atomic_replace.mod.o.cmd
>    │   │   ├── test_klp_atomic_replace.o
>    │   │   ├── .test_klp_atomic_replace.o.cmd
>    ...
> 
> On the other hand, variables like $TEST_GEN_FILES specify individual
> files, so only final binaries like test_klp-call_getpid (and not
> test_klp-call_getpid.c) are copied to $INSTALL_PATH.


Thank you Joe for finding this problem.

Copying source files and object files doesn't sound right. This isn't
how the ksleftest installs work. Let's fix this.

thanks,
--Shuah