From patchwork Mon Jul 31 13:43:39 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mark Brown X-Patchwork-Id: 13334829 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id D2A27C41513 for ; Mon, 31 Jul 2023 13:58:18 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231284AbjGaN6R (ORCPT ); Mon, 31 Jul 2023 09:58:17 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49708 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232733AbjGaN5f (ORCPT ); Mon, 31 Jul 2023 09:57:35 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id EC7F71992; Mon, 31 Jul 2023 06:53:55 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id B07BE61170; Mon, 31 Jul 2023 13:53:55 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 586ACC433C7; Mon, 31 Jul 2023 13:53:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1690811635; bh=Nuasx9Ylf/ySuoGV/J7jU7muHvsTQeng/1l4pki2YVk=; h=From:Date:Subject:References:In-Reply-To:To:Cc:From; b=bJ6uhN/VlZIp0R56Ffd3wDzi7jaN85ppo+IAx/PWWeciRbqGrjJI1R93hQ+Lb1vqW ope295R798wN3CCPYDI0JAB1ZRQw8sMtpNvV92bUJX9VMAgQXubjFhn7M9QUcolv0i ljef3V5JDycrHeOYlrhpLwE1po61OVC9eU7RtsTQz6ejS3nwQ0eUdzNPreeWy8C16Z WVZVb1Z2Vrx2rRowEZtJv7uJ3CpvhyYUzvpUy9J6GnohzMh9pU0G/87OugDzDFCy6k yzsDIYtYKMlURX4hMNX2NCMUNQJDYuRgN+fvXWqBKqGm2aMqvuJpapBmqxkUJkudQ2 Qr8C52EQJNo2Q== From: Mark Brown Date: Mon, 31 Jul 2023 14:43:39 +0100 Subject: [PATCH v3 30/36] kselftest/arm64: Always run signals tests with GCS enabled MIME-Version: 1.0 Message-Id: <20230731-arm64-gcs-v3-30-cddf9f980d98@kernel.org> References: <20230731-arm64-gcs-v3-0-cddf9f980d98@kernel.org> In-Reply-To: <20230731-arm64-gcs-v3-0-cddf9f980d98@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 , Kees Cook , Shuah Khan , "Rick P. Edgecombe" , Deepak Gupta , Ard Biesheuvel , Szabolcs Nagy Cc: "H.J. Lu" , Paul Walmsley , Palmer Dabbelt , Albert Ou , 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 0.13-dev-099c9 X-Developer-Signature: v=1; a=openpgp-sha256; l=3590; i=broonie@kernel.org; h=from:subject:message-id; bh=Nuasx9Ylf/ySuoGV/J7jU7muHvsTQeng/1l4pki2YVk=; b=owEBbQGS/pANAwAKASTWi3JdVIfQAcsmYgBkx7wrH0zwUuk7FPnLzR7tRFGoVnJN7Hd044By70s2 2lIh3teJATMEAAEKAB0WIQSt5miqZ1cYtZ/in+ok1otyXVSH0AUCZMe8KwAKCRAk1otyXVSH0O2BB/ 9USmKJiixGJgPi7T9rMsCaAQHXfYlrvrDXEBZw/NQ2LXUIpyvAQ3JIJG53quYjKOoUIpkMqGZ6Fy1s S3o9MGdqZQ0MhvXK/mUMy52Qhd5yGt7RqufPocJXpdAh5gTy++r0uT3bUJGAmoYx8iexZS8KPokD02 b1jOGp32ZHyYDos+KKE4b1KYHPCoQCtqa5HKmZ7YE0y438FEg8CNy3BLcgrdBCbBD0jpCA+U77x1hd MSv1bd7haQfERVvOZIOJSeSOb1IbyfJtuWmictYPS0M2oEffiS3sPBPl0a4ATpMcPYrP6oHk9Wf4s0 RwFxD9NfNNdwt/qeYb81OFY3FK1ycQ X-Developer-Key: i=broonie@kernel.org; a=openpgp; fpr=3F2568AAC26998F9E813A1C5C3F436CA30F5D8EB Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org 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(). 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 222093f51b67..1cea64986baa 100644 --- a/tools/testing/selftests/arm64/signal/test_signals_utils.h +++ b/tools/testing/selftests/arm64/signal/test_signals_utils.h @@ -16,6 +16,35 @@ 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)