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Date:   Fri, 19 Aug 2022 12:19:28 -0700
Message-Id: <20220819191929.480108-1-axelrasmussen@google.com>
Mime-Version: 1.0
Subject: [PATCH v2 1/2] selftests/vm: fix inability to build any vm tests
From:   Axel Rasmussen <axelrasmussen@google.com>
To:     Andrew Morton <akpm@linux-foundation.org>,
        Guillaume Tucker <guillaume.tucker@collabora.com>,
        "=?UTF-8?q?J=C3=A9r=C3=B4me=20Glisse?=" <jglisse@redhat.com>,
        John Hubbard <jhubbard@nvidia.com>,
        Shuah Khan <shuah@kernel.org>
Cc:     linux-kselftest@vger.kernel.org, linux-kernel@vger.kernel.org,
        linux-mm@kvack.org, Axel Rasmussen <axelrasmussen@google.com>
Content-Type: text/plain; charset="UTF-8"
Precedence: bulk

When we stopped using KSFT_KHDR_INSTALL, a side effect is we also
changed the value of `top_srcdir`. This can be seen by looking at the
code removed by commit 49de12ba06ef
("selftests: drop KSFT_KHDR_INSTALL make target").

(Note though that this commit didn't break this, technically the one
before it did since that's the one that stopped KSFT_KHDR_INSTALL from
being used, even though the code was still there.)

Previously lib.mk reconfigured `top_srcdir` when KSFT_KHDR_INSTALL was
being used. Now, that's no longer the case.

As a result, the path to gup_test.h in vm/Makefile was wrong, and
since it's a dependency of all of the vm binaries none of them could
be built. Instead, we'd get an "error" like:

    make[1]: *** No rule to make target
        '/[...]/tools/testing/selftests/vm/compaction_test', needed by
	'all'.  Stop.

So, modify lib.mk so it once again sets top_srcdir to the root of the
kernel tree.

Fixes: f2745dc0ba3d ("selftests: stop using KSFT_KHDR_INSTALL")
Signed-off-by: Axel Rasmussen <axelrasmussen@google.com>
---
 tools/testing/selftests/lib.mk | 1 +
 1 file changed, 1 insertion(+)

diff --git a/tools/testing/selftests/lib.mk b/tools/testing/selftests/lib.mk
index 947fc72413e9..d44c72b3abe3 100644
--- a/tools/testing/selftests/lib.mk
+++ b/tools/testing/selftests/lib.mk
@@ -40,6 +40,7 @@ ifeq (0,$(MAKELEVEL))
     endif
 endif
 selfdir = $(realpath $(dir $(filter %/lib.mk,$(MAKEFILE_LIST))))
+top_srcdir = $(selfdir)/../../..
 
 # The following are built by lib.mk common compile rules.
 # TEST_CUSTOM_PROGS should be used by tests that require
-- 
2.37.1.595.g718a3a8f04-goog