From: Kees Cook <keescook@chromium.org>
To: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Kees Cook <keescook@chromium.org>,
Guillaume Tucker <guillaume.tucker@collabora.com>,
David Laight <David.Laight@ACULAB.COM>,
stable@vger.kernel.org, Arnd Bergmann <arnd@arndb.de>,
linux-kernel@vger.kernel.org, kernelci@groups.io,
linux-kselftest@vger.kernel.org, linux-hardening@vger.kernel.org
Subject: [PATCH 1/9] selftests/lkdtm: Avoid needing explicit sub-shell
Date: Wed, 23 Jun 2021 13:39:28 -0700 [thread overview]
Message-ID: <20210623203936.3151093-2-keescook@chromium.org> (raw)
In-Reply-To: <20210623203936.3151093-1-keescook@chromium.org>
Some environments do not set $SHELL when running tests. There's no
need to use $SHELL here anyway, since "cat" can be used to receive any
delivered signals from the kernel. Additionally avoid using bash-isms
in the command, and record stderr for posterity.
Suggested-by: Guillaume Tucker <guillaume.tucker@collabora.com>
Suggested-by: David Laight <David.Laight@ACULAB.COM>
Fixes: 46d1a0f03d66 ("selftests/lkdtm: Add tests for LKDTM targets")
Cc: stable@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
---
tools/testing/selftests/lkdtm/run.sh | 12 ++++++++----
1 file changed, 8 insertions(+), 4 deletions(-)
diff --git a/tools/testing/selftests/lkdtm/run.sh b/tools/testing/selftests/lkdtm/run.sh
index bb7a1775307b..e95e79bd3126 100755
--- a/tools/testing/selftests/lkdtm/run.sh
+++ b/tools/testing/selftests/lkdtm/run.sh
@@ -76,10 +76,14 @@ fi
# Save existing dmesg so we can detect new content below
dmesg > "$DMESG"
-# Most shells yell about signals and we're expecting the "cat" process
-# to usually be killed by the kernel. So we have to run it in a sub-shell
-# and silence errors.
-($SHELL -c 'cat <(echo '"$test"') >'"$TRIGGER" 2>/dev/null) || true
+# Since the kernel is likely killing the process writing to the trigger
+# file, it must not be the script's shell itself. i.e. we cannot do:
+# echo "$test" >"$TRIGGER"
+# Instead, use "cat" to take the signal. Since the shell will yell about
+# the signal that killed the subprocess, we must ignore the failure and
+# continue. However we don't silence stderr since there might be other
+# useful details reported there in the case of other unexpected conditions.
+echo "$test" | cat >"$TRIGGER" || true
# Record and dump the results
dmesg | comm --nocheck-order -13 "$DMESG" - > "$LOG" || true
--
2.30.2
next prev parent reply other threads:[~2021-06-23 20:39 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-06-23 20:39 [PATCH 0/9] LKDTM: Improvements for kernelci.org Kees Cook
2021-06-23 20:39 ` Kees Cook [this message]
2021-06-23 20:39 ` [PATCH 2/9] selftests/lkdtm: Fix expected text for CR4 pinning Kees Cook
2021-06-23 20:39 ` [PATCH 3/9] selftests/lkdtm: Fix expected text for free poison Kees Cook
2021-06-23 20:39 ` [PATCH 4/9] lkdtm/bugs: XFAIL UNALIGNED_LOAD_STORE_WRITE Kees Cook
2021-06-23 20:39 ` [PATCH 5/9] lkdtm/heap: Add vmalloc linear overflow test Kees Cook
2021-06-23 20:39 ` [PATCH 6/9] lkdtm: Enable DOUBLE_FAULT on all architectures Kees Cook
2021-06-23 20:39 ` [PATCH 7/9] lkdtm: Add CONFIG hints in errors where possible Kees Cook
2021-06-23 20:39 ` [PATCH 8/9] selftests/lkdtm: Enable various testable CONFIGs Kees Cook
2021-06-23 20:39 ` [PATCH 9/9] lkdtm/heap: Add init_on_alloc tests Kees Cook
2021-06-24 13:32 ` [PATCH 0/9] LKDTM: Improvements for kernelci.org Greg Kroah-Hartman
2021-06-25 6:22 ` Guillaume Tucker
2021-06-26 6:12 ` Kees Cook
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