From patchwork Tue Aug 22 13:57:04 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mark Brown X-Patchwork-Id: 716314 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 002ACEE49A3 for ; Tue, 22 Aug 2023 14:12:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234829AbjHVOMf (ORCPT ); Tue, 22 Aug 2023 10:12:35 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43714 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234115AbjHVOMe (ORCPT ); Tue, 22 Aug 2023 10:12:34 -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 D5664CF7; Tue, 22 Aug 2023 07:12:09 -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 1368C657F2; Tue, 22 Aug 2023 14:06:22 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id B54DBC433CA; Tue, 22 Aug 2023 14:06:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1692713181; bh=Nuasx9Ylf/ySuoGV/J7jU7muHvsTQeng/1l4pki2YVk=; h=From:Date:Subject:References:In-Reply-To:To:Cc:From; b=MqAwb/aWxREwi9w3daLu0ewAyXCvv6r/RCVXRhhcSOIAkDUF0lGX9nzO4iiqQTH6x AsYtF89WylBwuYjEQf8qAuzSf8g4oVDmufDb8abGzwwdBWy+OhEhFYhFfdfHqa4P/+ jlxNmMfibruPS3XserjLyma1YWPCWPBFF/5Bg7zW+d8uovlRM/WN8201iM6MgJirXG CbL8oShaVgiSN8f4YOBnQ4zm1uJ4EzlzkKkAnLbV1LWFNtkWUQLsPaHja7q7DPhLNI jDheQxm71CxrbYXWYn8aDD3CPMttYd6E7v4eQxNmjx0n1e8k8LUIB28zy8hZH0tW9e G6AsrAEV4ALzQ== From: Mark Brown Date: Tue, 22 Aug 2023 14:57:04 +0100 Subject: [PATCH v5 31/37] kselftest/arm64: Always run signals tests with GCS enabled MIME-Version: 1.0 Message-Id: <20230822-arm64-gcs-v5-31-9ef181dd6324@kernel.org> References: <20230822-arm64-gcs-v5-0-9ef181dd6324@kernel.org> In-Reply-To: <20230822-arm64-gcs-v5-0-9ef181dd6324@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-034f2 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/pANAwAKASTWi3JdVIfQAcsmYgBk5MAIYtmVyvEH4RH6kobbZ8dzV0Gh6wuRozucrRx7 JOJxU7qJATMEAAEKAB0WIQSt5miqZ1cYtZ/in+ok1otyXVSH0AUCZOTACAAKCRAk1otyXVSH0CCEB/ 9N3VecI4j96Dnvvms8ya9WkFGh6Q+CSjjT5/AqC8D3DTGm5A5sBZVKIlFaeCvdh4EB/LeXgLHAXebT 2O38tF8Or4+k4HX6rV9gB+E7oN/Fw/GEPEjINm9fqHQRneMAp36veUqZxzay6pLDW9uLUfQ5SPboIX rxqlKPLBnX217YDQGBzgL2YTTetcZU/iMkZDQ0siZsz2w6Mp2EET9m2X9RIc76wLVEF3woH68SoqGW BsvzbOJPfmzYTZbxJvYsqZCKLfyRaMnp32w7hkRP9EW0AbPC25SpEUEDHLzlPJ4wC7YmQHlLKLok4q UTYrhIX6jwnyJPUXPxpjYgqctF8DuY X-Developer-Key: i=broonie@kernel.org; a=openpgp; fpr=3F2568AAC26998F9E813A1C5C3F436CA30F5D8EB Precedence: bulk List-ID: X-Mailing-List: linux-kselftest@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)