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Date:   Fri, 24 Jun 2022 00:12:47 +0000
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Subject: [PATCH 2/2] kunit: add coverage_uml.config to enable GCOV on UML
From:   Daniel Latypov <dlatypov@google.com>
To:     brendanhiggins@google.com, davidgow@google.com
Cc:     linux-kernel@vger.kernel.org, kunit-dev@googlegroups.com,
        linux-kselftest@vger.kernel.org, skhan@linuxfoundation.org,
        Daniel Latypov <dlatypov@google.com>
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Precedence: bulk

Now that kunit.py's --kunitconfig is repeatable, let's create a file to
hold the various options needed to enable coverage under UML.

This can be used like so:
$ ./tools/testing/kunit/kunit.py run \
  --kunitconfig=tools/testing/kunit/configs/all_tests_uml.config \
  --kunitconfig=tools/testing/kunit/configs/coverage_uml.config \
  --make_options=CC=/usr/bin/gcc-6

which on my system is enough to get coverage working [1].

This is still a clunky command, but far better than before.

[1] at the time of this commit, I get:
  Overall coverage rate:
    lines......: 11.6% (34112 of 295033 lines)
    functions..: 15.3% (3721 of 24368 functions)

Signed-off-by: Daniel Latypov <dlatypov@google.com>
---
 Documentation/dev-tools/kunit/running_tips.rst  |  3 +--
 tools/testing/kunit/configs/coverage_uml.config | 11 +++++++++++
 2 files changed, 12 insertions(+), 2 deletions(-)
 create mode 100644 tools/testing/kunit/configs/coverage_uml.config

diff --git a/Documentation/dev-tools/kunit/running_tips.rst b/Documentation/dev-tools/kunit/running_tips.rst
index c36f6760087d..205ea21c9cca 100644
--- a/Documentation/dev-tools/kunit/running_tips.rst
+++ b/Documentation/dev-tools/kunit/running_tips.rst
@@ -123,8 +123,7 @@ Putting it together into a copy-pastable sequence of commands:
 .. code-block:: bash
 
 	# Append coverage options to the current config
-	$ echo -e "CONFIG_DEBUG_KERNEL=y\nCONFIG_DEBUG_INFO=y\nCONFIG_DEBUG_INFO_DWARF_TOOLCHAIN_DEFAULT=y\nCONFIG_GCOV=y" >> .kunit/.kunitconfig
-	$ ./tools/testing/kunit/kunit.py run
+	$ ./tools/testing/kunit/kunit.py run --kunitconfig=.kunit/ --kunitconfig=tools/testing/kunit/configs/coverage_uml.config
 	# Extract the coverage information from the build dir (.kunit/)
 	$ lcov -t "my_kunit_tests" -o coverage.info -c -d .kunit/
 
diff --git a/tools/testing/kunit/configs/coverage_uml.config b/tools/testing/kunit/configs/coverage_uml.config
new file mode 100644
index 000000000000..bacb77664fa8
--- /dev/null
+++ b/tools/testing/kunit/configs/coverage_uml.config
@@ -0,0 +1,11 @@
+# This config fragment enables coverage on UML, which is different from the
+# normal gcov used in other arches (no debugfs).
+# Example usage:
+# ./tools/testing/kunit/kunit.py run \
+#   --kunitconfig=tools/testing/kunit/configs/all_tests_uml.config \
+#   --kunitconfig=tools/testing/kunit/configs/coverage_uml.config
+
+CONFIG_DEBUG_KERNEL=y
+CONFIG_DEBUG_INFO=y
+CONFIG_DEBUG_INFO_DWARF_TOOLCHAIN_DEFAULT=y
+CONFIG_GCOV=y
-- 
2.37.0.rc0.104.g0611611a94-goog