From patchwork Mon Nov 20 23:54:32 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mark Brown X-Patchwork-Id: 745539 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id C72A53B2B7; Mon, 20 Nov 2023 23:55:51 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="Pt33pMEF" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 05943C433C7; Mon, 20 Nov 2023 23:55:45 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1700524551; bh=ZmJrvmANp1kG9kAUuq4ZkamJ4qQyGfBTGbaFEhsSApg=; h=From:Date:Subject:References:In-Reply-To:To:Cc:From; b=Pt33pMEF/POpoykTVCH0esLyYbbCA2/MuiuNDDhdvAugx8KFmw1tKn0bSGo7z/oz+ uTpvArUvH/uYX6qe3ShTmgtb/T6RI1JePjh5tg6z8p4WQUWyFTWhQGtSjDAQi6USTW qKzFTWEAc1f0yTUnxW2TqUOqSj/TDffFDIrcVSJSKvu2b/rm32KMmTLetFUaxI2qal zzcfIzZ92zr1qyK6uxLuX4aO0Furel8hX3pF/t4W7FuxsrDGCs2C30kEhECaAG59Vm kYB+l7BGTqAm8k9FyACmKx1cePKJkZg6iGWC2yRou1kXBfFGtINk7Ro4mDGyALeYtE TEMF/bL6tIPNg== From: Mark Brown Date: Mon, 20 Nov 2023 23:54:32 +0000 Subject: [PATCH RFT v3 4/5] selftests/clone3: Allow tests to flag if -E2BIG is a valid error code Precedence: bulk X-Mailing-List: linux-kselftest@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Message-Id: <20231120-clone3-shadow-stack-v3-4-a7b8ed3e2acc@kernel.org> References: <20231120-clone3-shadow-stack-v3-0-a7b8ed3e2acc@kernel.org> In-Reply-To: <20231120-clone3-shadow-stack-v3-0-a7b8ed3e2acc@kernel.org> To: "Rick P. Edgecombe" , Deepak Gupta , Szabolcs Nagy , "H.J. Lu" , Florian Weimer , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , x86@kernel.org, "H. Peter Anvin" , Peter Zijlstra , Juri Lelli , Vincent Guittot , Dietmar Eggemann , Steven Rostedt , Ben Segall , Mel Gorman , Daniel Bristot de Oliveira , Valentin Schneider , Christian Brauner , Shuah Khan Cc: linux-kernel@vger.kernel.org, Catalin Marinas , Will Deacon , Kees Cook , jannh@google.com, bsegall@google.com, linux-kselftest@vger.kernel.org, linux-api@vger.kernel.org, Mark Brown X-Mailer: b4 0.13-dev-0438c X-Developer-Signature: v=1; a=openpgp-sha256; l=1887; i=broonie@kernel.org; h=from:subject:message-id; bh=ZmJrvmANp1kG9kAUuq4ZkamJ4qQyGfBTGbaFEhsSApg=; b=owEBbQGS/pANAwAKASTWi3JdVIfQAcsmYgBlW/Hhnma1u0qT3kkylcajBZLZYCk8NKYNAoP26I5f MjRNpjiJATMEAAEKAB0WIQSt5miqZ1cYtZ/in+ok1otyXVSH0AUCZVvx4QAKCRAk1otyXVSH0GubB/ 930Z/P0fuK5MX34Cy4dkfAwusyWEBKeRlq5NwdEPpqMld6z0jmCDctq4ZM5xWaF1ZYbS+rLB1ZAuHU OWz4yL3h9ZysR3RtjxxJCdN+91hooUs0KMPMZjkwQ6b5Zlxd9VIP1oOqU1cyZCEEidqERh2jRelK+E bF31tT3a+VziuPw1P7FBseViqvx+pKNyUIkdof/DR2OnHkxe0578uGYGat1WoJnmImpaoO/qV7mJVy HcGbCOl/Djx4qpYi5WjVW0f6UgWHpRjRIqfxCLzpwG5+O7EMUGTWuh3ngitrCL7rb4jJnZ/QqDNu2I +xNCeJWCK33IoNahE8vywB6sFw8MZH X-Developer-Key: i=broonie@kernel.org; a=openpgp; fpr=3F2568AAC26998F9E813A1C5C3F436CA30F5D8EB The clone_args structure is extensible, with the syscall passing in the length of the structure. Inside the kernel we use copy_struct_from_user() to read the struct but this has the unfortunate side effect of silently accepting some overrun in the structure size providing the extra data is all zeros. This means that we can't discover the clone3() features that the running kernel supports by simply probing with various struct sizes. We need to check this for the benefit of test systems which run newer kselftests on old kernels. Add a flag which can be set on a test to indicate that clone3() may return -E2BIG due to the use of newer struct versions. Currently no tests need this but it will become an issue for testing clone3() support for shadow stacks, the support for shadow stacks is already present on x86. Signed-off-by: Mark Brown --- tools/testing/selftests/clone3/clone3.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/tools/testing/selftests/clone3/clone3.c b/tools/testing/selftests/clone3/clone3.c index 1108bd8e36d6..6adbfd14c841 100644 --- a/tools/testing/selftests/clone3/clone3.c +++ b/tools/testing/selftests/clone3/clone3.c @@ -39,6 +39,7 @@ struct test { size_t size; size_function size_function; int expected; + bool e2big_valid; enum test_mode test_mode; filter_function filter; }; @@ -141,6 +142,11 @@ static void test_clone3(const struct test *test) ksft_print_msg("[%d] clone3() with flags says: %d expected %d\n", getpid(), ret, test->expected); if (ret != test->expected) { + if (test->e2big_valid && ret == -E2BIG) { + ksft_print_msg("Test reported -E2BIG\n"); + ksft_test_result_skip("%s\n", test->name); + return; + } ksft_print_msg( "[%d] Result (%d) is different than expected (%d)\n", getpid(), ret, test->expected);