selftests: Print the test we're running to /dev/kmsg

[ Upstream commit 88893cf787d3062c631cc20b875068eb11756e03 ]

Some tests cause the kernel to print things to the kernel log
buffer (ie. printk), in particular oops and warnings etc. However when
running all the tests in succession it's not always obvious which
test(s) caused the kernel to print something.

We can narrow it down by printing which test directory we're running
in to /dev/kmsg, if it's writable.

Example output:

  [  170.149149] kselftest: Running tests in powerpc
  [  305.300132] kworker/dying (71) used greatest stack depth: 7776 bytes
                 left
  [  808.915456] kselftest: Running tests in pstore

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Shuah Khan <shuahkh@osg.samsung.com>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/tools/testing/selftests/Makefile b/tools/testing/selftests/Makefile
index 3c9c0bbe7dbb669786f6700c8418f35edc74b6b6..ea300e7818a70cddef099096fcfe92d54b470e84 100644 (file)
--- a/tools/testing/selftests/Makefile
+++ b/tools/testing/selftests/Makefile
@@ -122,6 +122,7 @@ ifdef INSTALL_PATH
                BUILD_TARGET=$$BUILD/$$TARGET;  \
                echo "echo ; echo Running tests in $$TARGET" >> $(ALL_SCRIPT); \
                echo "echo ========================================" >> $(ALL_SCRIPT); \
+               echo "[ -w /dev/kmsg ] && echo \"kselftest: Running tests in $$TARGET\" >> /dev/kmsg" >> $(ALL_SCRIPT); \
                echo "cd $$TARGET" >> $(ALL_SCRIPT); \
                make -s --no-print-directory OUTPUT=$$BUILD_TARGET -C $$TARGET emit_tests >> $(ALL_SCRIPT); \
                echo "cd \$$ROOT" >> $(ALL_SCRIPT); \