From patchwork Wed Aug 28 23:27:48 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mark Brown X-Patchwork-Id: 823737 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 C1B401AED54; Wed, 28 Aug 2024 23:32:27 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1724887947; cv=none; b=P7PCENq817D5ntq3tyjsAGCAPRaIbf4pJxJIiNA9TqUleTu7iOVIBt7QU4+hCYsYHjp84BRLt/Lp5EjD/WDw5VASimH9p4FVb6vp+NDXp8sRRPfmCufzm4teLI3s6HKACSViepYGanrpVXj0Nm2g3ILliQBzhF6qMYvJEBGmFm4= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1724887947; c=relaxed/simple; bh=LmUMQLV4QzyWbEviejJtcrr2Je4DeKbVGxPr/Gcjy80=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=bwaD+ik+YLZFh+sXQvOep+TBIJ2pVfVig4lqdu9F4tweahhVBARabYergCQbONZo1AybxuM6ShF/C4SVgaVitt+CnBRl7PtSWloDWzAsx9LxOfDx+kVHaa+7n/UC0owfBZQ+SKS25EWo2QRRgc2um9O/OYQ8eXvTnMm3gsCUrfc= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=Yo+G3Y1d; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="Yo+G3Y1d" Received: by smtp.kernel.org (Postfix) with ESMTPSA id AA4EAC4CEC4; Wed, 28 Aug 2024 23:32:20 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1724887947; bh=LmUMQLV4QzyWbEviejJtcrr2Je4DeKbVGxPr/Gcjy80=; h=From:Date:Subject:References:In-Reply-To:To:Cc:From; b=Yo+G3Y1dv7GnDX5sTlqu0aSf+rtD4iD5Omwol0K/btoCawqfOwzBtlu/HePFln7W6 pj6wzdFJOnt4abXEezeLTU4ZKXpXANOYv9ZN8ZHQjmCY0wMFEyERMFvgug9TH+Ercm R8X9NBSg7WUi+Uom8Ll2COgb/TOsYjN6X6+eFIYwN9j2KR88pf+DxOUX9FIQByJBl4 J8WVj1AJoqZWzprXHY+zH0PMi172fhNqSRIqYYBs5pIv2l8xLT/GrXQkEeceYPQ3ss g4oB5A3tvV7hBEWpQheTYU/lbUEJaaXVwRAs1Kk2/uKKNHzDqqXRefnUYkCKe8kNQ1 ZUphfckErBZmg== From: Mark Brown Date: Thu, 29 Aug 2024 00:27:48 +0100 Subject: [PATCH v12 32/39] kselftest/arm64: Always run signals tests with GCS enabled Precedence: bulk X-Mailing-List: linux-kselftest@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Message-Id: <20240829-arm64-gcs-v12-32-42fec947436a@kernel.org> References: <20240829-arm64-gcs-v12-0-42fec947436a@kernel.org> In-Reply-To: <20240829-arm64-gcs-v12-0-42fec947436a@kernel.org> To: Catalin Marinas , Will Deacon , Jonathan Corbet , Andrew Morton , Marc Zyngier , Oliver Upton , James Morse , Suzuki K Poulose , Arnd Bergmann , Oleg Nesterov , Eric Biederman , Shuah Khan , "Rick P. Edgecombe" , Deepak Gupta , Ard Biesheuvel , Szabolcs Nagy , Kees Cook Cc: "H.J. Lu" , Paul Walmsley , Palmer Dabbelt , Albert Ou , Florian Weimer , Christian Brauner , Thiago Jung Bauermann , Ross Burton , Yury Khrustalev , Wilco Dijkstra , linux-arm-kernel@lists.infradead.org, linux-doc@vger.kernel.org, kvmarm@lists.linux.dev, linux-fsdevel@vger.kernel.org, linux-arch@vger.kernel.org, linux-mm@kvack.org, linux-kselftest@vger.kernel.org, linux-kernel@vger.kernel.org, linux-riscv@lists.infradead.org, Mark Brown X-Mailer: b4 0.15-dev-37811 X-Developer-Signature: v=1; a=openpgp-sha256; l=3656; i=broonie@kernel.org; h=from:subject:message-id; bh=LmUMQLV4QzyWbEviejJtcrr2Je4DeKbVGxPr/Gcjy80=; b=owEBbQGS/pANAwAKASTWi3JdVIfQAcsmYgBmz7KRKBtlJjI7Gzj4Vuot/p0NBuCI/yCs//ZD3kBC 7c8tviaJATMEAAEKAB0WIQSt5miqZ1cYtZ/in+ok1otyXVSH0AUCZs+ykQAKCRAk1otyXVSH0P9zB/ 9nEW1mD6eVDzW51m2iIGMw4cv6+muKA/GhCv+TWLcwMt6FV9Iv6c/edDtVUfoyc2faQhNydiZk/K3X fDNMrAoRVooJ1ArIhS51lDpTUtr9Dk7IitOwDJUl+tEX663nYtvucH3Rc3+IvfYo/s9PEZR7V8SlAQ 5iDiW+7JHGh57hlils5zRUmPnhpI9Z2kJ4ee7T1EJ0a4WBIHecsjo75r9GJbwgPIlIMujN91W2EfT/ 5QnLyYRM+cgh/ypnViV6wSegKwH8GYyMt4aYkP8JjQnaWs+VMsUZ7KwpEQPz38wfl6xD09pLrvzgDa GkryFgfNGXppQ912UYnRMOdJBaQJB2 X-Developer-Key: i=broonie@kernel.org; a=openpgp; fpr=3F2568AAC26998F9E813A1C5C3F436CA30F5D8EB Since it is not possible to return from the function that enabled GCS without disabling GCS it is very inconvenient to use the signal handling tests to cover GCS when GCS is not enabled by the toolchain and runtime, something that no current distribution does. Since none of the testcases do anything with stacks that would cause problems with GCS we can sidestep this issue by unconditionally enabling GCS on startup and exiting with a call to exit() rather than a return from main(). Reviewed-by: Thiago Jung Bauermann Signed-off-by: Mark Brown --- .../testing/selftests/arm64/signal/test_signals.c | 17 ++++++++++++- .../selftests/arm64/signal/test_signals_utils.h | 29 ++++++++++++++++++++++ 2 files changed, 45 insertions(+), 1 deletion(-) diff --git a/tools/testing/selftests/arm64/signal/test_signals.c b/tools/testing/selftests/arm64/signal/test_signals.c index 00051b40d71e..30e95f50db19 100644 --- a/tools/testing/selftests/arm64/signal/test_signals.c +++ b/tools/testing/selftests/arm64/signal/test_signals.c @@ -7,6 +7,10 @@ * Each test provides its own tde struct tdescr descriptor to link with * this wrapper. Framework provides common helpers. */ + +#include +#include + #include #include "test_signals.h" @@ -16,6 +20,16 @@ struct tdescr *current = &tde; int main(int argc, char *argv[]) { + /* + * Ensure GCS is at least enabled throughout the tests if + * supported, otherwise the inability to return from the + * function that enabled GCS makes it very inconvenient to set + * up test cases. The prctl() may fail if GCS was locked by + * libc setup code. + */ + if (getauxval(AT_HWCAP2) & HWCAP2_GCS) + gcs_set_state(PR_SHADOW_STACK_ENABLE); + ksft_print_msg("%s :: %s\n", current->name, current->descr); if (test_setup(current) && test_init(current)) { test_run(current); @@ -23,5 +37,6 @@ int main(int argc, char *argv[]) } test_result(current); - return current->result; + /* Do not return in case GCS was enabled */ + exit(current->result); } diff --git a/tools/testing/selftests/arm64/signal/test_signals_utils.h b/tools/testing/selftests/arm64/signal/test_signals_utils.h index 762c8fe9c54a..1e80808ee105 100644 --- a/tools/testing/selftests/arm64/signal/test_signals_utils.h +++ b/tools/testing/selftests/arm64/signal/test_signals_utils.h @@ -18,6 +18,35 @@ void test_cleanup(struct tdescr *td); int test_run(struct tdescr *td); void test_result(struct tdescr *td); +#ifndef __NR_prctl +#define __NR_prctl 167 +#endif + +/* + * The prctl takes 1 argument but we need to ensure that the other + * values passed in registers to the syscall are zero since the kernel + * validates them. + */ +#define gcs_set_state(state) \ + ({ \ + register long _num __asm__ ("x8") = __NR_prctl; \ + register long _arg1 __asm__ ("x0") = PR_SET_SHADOW_STACK_STATUS; \ + register long _arg2 __asm__ ("x1") = (long)(state); \ + register long _arg3 __asm__ ("x2") = 0; \ + register long _arg4 __asm__ ("x3") = 0; \ + register long _arg5 __asm__ ("x4") = 0; \ + \ + __asm__ volatile ( \ + "svc #0\n" \ + : "=r"(_arg1) \ + : "r"(_arg1), "r"(_arg2), \ + "r"(_arg3), "r"(_arg4), \ + "r"(_arg5), "r"(_num) \ + : "memory", "cc" \ + ); \ + _arg1; \ + }) + static inline bool feats_ok(struct tdescr *td) { if (td->feats_incompatible & td->feats_supported)