Re: [GIT PULL] Kselftest update for Linux 5.20-rc1

[Shuah Khan]

On 8/2/22 3:51 AM, Mickaël Salaün wrote:
> Hi,
>
> This change breaks the Landlock test build when performed on the tools/testing/selftests/landlock directory because the (non-system/up-to-date) kernel headers aren't found. Looking at the use of top_srcdir and HDR_PATH, it seems that multiple subsystems are using this feature. I consider this change a regression.

I did a build test from the top level before sending the pull request
and didn't catch this breakage as a result. This breaks when build is
run from the test directory.

We have had several problems related to khdr_dir and target and decided
to move away from it with this change.

> It also removes the check on up-to-date kernel headers (thanks to the Makefile's target timestamp).
>
> I wasn't CCed for this change impacting Landlock [1]. Please keep in mind to add at least maintainers and related mailing-lists for changes on related subsystems.

That is the usual practice and if I notice missing maintainers, I add
them. We missed this one.

> The following patch almost revert commit a917dd94b832 ("selftests/landlock: drop deprecated headers dependency") and partially fixes commit 49de12ba06ef ("selftests: drop KSFT_KHDR_INSTALL make target"):

Guillaume,

Will you be able to look at this and send a patch on top? I will
send another pull request before merge window closes?

> --- a/tools/testing/selftests/landlock/Makefile
> +++ b/tools/testing/selftests/landlock/Makefile
> @@ -9,10 +9,13 @@ TEST_GEN_PROGS := $(src_test:.c=)
>   TEST_GEN_PROGS_EXTENDED := true
>
>   OVERRIDE_TARGETS := 1
> +top_srcdir = ../../../..
>   include ../lib.mk
>
> +khdr_dir = $(top_srcdir)/usr/include
> +
>   $(OUTPUT)/true: true.c
>       $(LINK.c) $< $(LDLIBS) -o $@ -static
>
> -$(OUTPUT)/%_test: %_test.c ../kselftest_harness.h common.h
> -    $(LINK.c) $< $(LDLIBS) -o $@ -lcap
> +$(OUTPUT)/%_test: %_test.c $(khdr_dir)/linux/landlock.h ../kselftest_harness.h common.h
> +    $(LINK.c) $< $(LDLIBS) -o $@ -lcap -I$(khdr_dir)
>
>
> This doesn't fix the header timestamp check though.

thanks,
-- Shuah