From patchwork Mon Jul 12 06:01:56 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg Kroah-Hartman X-Patchwork-Id: 474112 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-19.4 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER, INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, URIBL_BLOCKED, USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 368E3C11F68 for ; Mon, 12 Jul 2021 06:57:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 2CAA7611C2 for ; Mon, 12 Jul 2021 06:57:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240387AbhGLHAh (ORCPT ); Mon, 12 Jul 2021 03:00:37 -0400 Received: from mail.kernel.org ([198.145.29.99]:33308 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S239955AbhGLG6j (ORCPT ); Mon, 12 Jul 2021 02:58:39 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 426C261380; Mon, 12 Jul 2021 06:55:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1626072951; bh=RCjUG2JQ5Fn9D2AgnyWAr3vvbV9vOEIeYuaB+5de45g=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=oFn3lwk1OxXYuvmi2+XFq3PpBSqzotW0Gaqm5p0g8dAv2jn3wYW9gveQkCmZTUl8x Qt5v26WB3pNcmhk2LDcByUwO1ITwT4pt5SrXWQ/zRNLPpMs8rShsnsokgb0npFTM8G HE1RPrIBrRyD5BVTjVDvKqgF9af6JjYGJdZMbMTM= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Guillaume Tucker , David Laight , Kees Cook Subject: [PATCH 5.12 033/700] selftests/lkdtm: Avoid needing explicit sub-shell Date: Mon, 12 Jul 2021 08:01:56 +0200 Message-Id: <20210712060929.311193615@linuxfoundation.org> X-Mailer: git-send-email 2.32.0 In-Reply-To: <20210712060924.797321836@linuxfoundation.org> References: <20210712060924.797321836@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Kees Cook commit 04831e892b41618914b2123ae3b4fa77252e8656 upstream. Some environments do not set $SHELL when running tests. There's no need to use $SHELL here anyway, since "cat" can be used to receive any delivered signals from the kernel. Additionally avoid using bash-isms in the command, and record stderr for posterity. Fixes: 46d1a0f03d66 ("selftests/lkdtm: Add tests for LKDTM targets") Cc: stable@vger.kernel.org Suggested-by: Guillaume Tucker Suggested-by: David Laight Signed-off-by: Kees Cook Link: https://lore.kernel.org/r/20210623203936.3151093-2-keescook@chromium.org Signed-off-by: Greg Kroah-Hartman Signed-off-by: Greg Kroah-Hartman --- tools/testing/selftests/lkdtm/run.sh | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-) --- a/tools/testing/selftests/lkdtm/run.sh +++ b/tools/testing/selftests/lkdtm/run.sh @@ -76,10 +76,14 @@ fi # Save existing dmesg so we can detect new content below dmesg > "$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