From patchwork Mon Aug 7 22:00:39 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mark Brown X-Patchwork-Id: 711395 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 E6374C001B0 for ; Mon, 7 Aug 2023 22:08:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231696AbjHGWIx (ORCPT ); Mon, 7 Aug 2023 18:08:53 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46772 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231557AbjHGWI1 (ORCPT ); Mon, 7 Aug 2023 18:08:27 -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 596142D45; Mon, 7 Aug 2023 15:05:45 -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 CAEC86229A; Mon, 7 Aug 2023 22:05:04 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 77DE6C433B6; Mon, 7 Aug 2023 22:04:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1691445904; bh=VKZ6TiHFuT5aAiOwah57tTttkzurhwux6QHXIkpaxF8=; h=From:Date:Subject:References:In-Reply-To:To:Cc:From; b=rVZbPBZdwcP1QVYU6kAOqJoyG/aALvVi0kYIKgykOU8JY26+tMgaGCV9jiq01ORMf ZTB6wpxJpaSJzP8w+xtLeV+ipSQxFee6KDpuW3RdjGwFeZt+PzJNwRTXBrOqTAagUf TYA34Zr0NG4B/QobaUEQu5mSh25QBBiXVYMnE/9P3hTBmm9BK2s/LV8K+YBcUAi2ul XP2dYs+yLcd26s6YfArVZkEbhjHliRWgM2OQPae/d8guWmHMi0WKC62qRCXI6aMsNJ PgXv38r1L0tkDLCu4CD7Xttf7Sp8BkirhQH+OQrvis+saB2JVxL2FU2yUmToTfXn81 fbeKk5+ZJ8Dyg== From: Mark Brown Date: Mon, 07 Aug 2023 23:00:39 +0100 Subject: [PATCH v4 34/36] selftests/arm64: Add GCS signal tests MIME-Version: 1.0 Message-Id: <20230807-arm64-gcs-v4-34-68cfa37f9069@kernel.org> References: <20230807-arm64-gcs-v4-0-68cfa37f9069@kernel.org> In-Reply-To: <20230807-arm64-gcs-v4-0-68cfa37f9069@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=7313; i=broonie@kernel.org; h=from:subject:message-id; bh=VKZ6TiHFuT5aAiOwah57tTttkzurhwux6QHXIkpaxF8=; b=owEBbQGS/pANAwAKASTWi3JdVIfQAcsmYgBk0WmzUF0Z16avH6vwqIGlUoQuzjpHKAhiGUXv4Yq3 xnBMpQmJATMEAAEKAB0WIQSt5miqZ1cYtZ/in+ok1otyXVSH0AUCZNFpswAKCRAk1otyXVSH0PXsB/ wIXBuyl7TwMToWk0pF3iIL5vPvG2Da/HuEVfn3BBVOX0MzvHi5qY7ABZl0J6OakkbOeiXeu6acuJ+j EGTqWt65KeKB4slWqhxbRqVYjTgiwEfGoMfQX+PfUSPjOv+7X768j9K0Q3NVJ2N2UVrK0pRPKFJ5HS i+mvYUv8paijzpaIWINQF3Gu9wMMPGKXuzXSR+AyJdFKoU+F28WhsXWUSBNYHNOaIQ7F/ZoRfzoKAJ u44+kCYldV4ldEmNyqu3W5nC8F9KxUaaO0G6BWXzSyIzlSioEnGS9+X7R0m8fEh7p+HBF0O8D2eLh+ VRy4iequkHzLnQGjatv+c9mdheOhj4 X-Developer-Key: i=broonie@kernel.org; a=openpgp; fpr=3F2568AAC26998F9E813A1C5C3F436CA30F5D8EB Precedence: bulk List-ID: X-Mailing-List: linux-kselftest@vger.kernel.org Do some testing of the signal handling for GCS, checking that a GCS frame has the expected information in it and that the expected signals are delivered with invalid operations. Signed-off-by: Mark Brown --- tools/testing/selftests/arm64/signal/.gitignore | 1 + .../selftests/arm64/signal/test_signals_utils.h | 10 +++ .../arm64/signal/testcases/gcs_exception_fault.c | 59 ++++++++++++++++ .../selftests/arm64/signal/testcases/gcs_frame.c | 78 ++++++++++++++++++++++ .../arm64/signal/testcases/gcs_write_fault.c | 67 +++++++++++++++++++ 5 files changed, 215 insertions(+) diff --git a/tools/testing/selftests/arm64/signal/.gitignore b/tools/testing/selftests/arm64/signal/.gitignore index 839e3a252629..26de12918890 100644 --- a/tools/testing/selftests/arm64/signal/.gitignore +++ b/tools/testing/selftests/arm64/signal/.gitignore @@ -1,6 +1,7 @@ # SPDX-License-Identifier: GPL-2.0-only mangle_* fake_sigreturn_* +gcs_* sme_* ssve_* sve_* diff --git a/tools/testing/selftests/arm64/signal/test_signals_utils.h b/tools/testing/selftests/arm64/signal/test_signals_utils.h index 1cea64986baa..d41f237db28d 100644 --- a/tools/testing/selftests/arm64/signal/test_signals_utils.h +++ b/tools/testing/selftests/arm64/signal/test_signals_utils.h @@ -6,6 +6,7 @@ #include #include +#include #include #include "test_signals.h" @@ -45,6 +46,15 @@ void test_result(struct tdescr *td); _arg1; \ }) +static inline __attribute__((always_inline)) uint64_t get_gcspr_el0(void) +{ + uint64_t val; + + asm volatile("mrs %0, S3_3_C2_C5_1" : "=r" (val)); + + return val; +} + static inline bool feats_ok(struct tdescr *td) { if (td->feats_incompatible & td->feats_supported) diff --git a/tools/testing/selftests/arm64/signal/testcases/gcs_exception_fault.c b/tools/testing/selftests/arm64/signal/testcases/gcs_exception_fault.c new file mode 100644 index 000000000000..532d533592a1 --- /dev/null +++ b/tools/testing/selftests/arm64/signal/testcases/gcs_exception_fault.c @@ -0,0 +1,59 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (C) 2023 ARM Limited + */ + +#include +#include +#include + +#include +#include + +#include "test_signals_utils.h" +#include "testcases.h" + +/* This should be includable from some standard header, but which? */ +#ifndef SEGV_CPERR +#define SEGV_CPERR 10 +#endif + +static inline void gcsss1(uint64_t Xt) +{ + asm volatile ( + "sys #3, C7, C7, #2, %0\n" + : + : "rZ" (Xt) + : "memory"); +} + +static int gcs_op_fault_trigger(struct tdescr *td) +{ + /* + * The slot below our current GCS should be in a valid GCS but + * must not have a valid cap in it. + */ + gcsss1(get_gcspr_el0() - 8); + + return 0; +} + +static int gcs_op_fault_signal(struct tdescr *td, siginfo_t *si, + ucontext_t *uc) +{ + ASSERT_GOOD_CONTEXT(uc); + + return 1; +} + +struct tdescr tde = { + .name = "Invalid GCS operation", + .descr = "An invalid GCS operation generates the expected signal", + .feats_required = FEAT_GCS, + .timeout = 3, + .sig_ok = SIGSEGV, + .sig_ok_code = SEGV_CPERR, + .sanity_disabled = true, + .trigger = gcs_op_fault_trigger, + .run = gcs_op_fault_signal, +}; diff --git a/tools/testing/selftests/arm64/signal/testcases/gcs_frame.c b/tools/testing/selftests/arm64/signal/testcases/gcs_frame.c new file mode 100644 index 000000000000..d67cb26195a6 --- /dev/null +++ b/tools/testing/selftests/arm64/signal/testcases/gcs_frame.c @@ -0,0 +1,78 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (C) 2023 ARM Limited + */ + +#include +#include +#include + +#include "test_signals_utils.h" +#include "testcases.h" + +static union { + ucontext_t uc; + char buf[1024 * 64]; +} context; + +static int gcs_regs(struct tdescr *td, siginfo_t *si, ucontext_t *uc) +{ + size_t offset; + struct _aarch64_ctx *head = GET_BUF_RESV_HEAD(context); + struct gcs_context *gcs; + unsigned long expected, gcspr; + int ret; + + ret = prctl(PR_GET_SHADOW_STACK_STATUS, &expected, 0, 0, 0); + if (ret != 0) { + fprintf(stderr, "Unable to query GCS status\n"); + return 1; + } + + /* We expect a cap to be added to the GCS in the signal frame */ + gcspr = get_gcspr_el0(); + gcspr -= 8; + fprintf(stderr, "Expecting GCSPR_EL0 %lx\n", gcspr); + + if (!get_current_context(td, &context.uc, sizeof(context))) { + fprintf(stderr, "Failed getting context\n"); + return 1; + } + fprintf(stderr, "Got context\n"); + + head = get_header(head, GCS_MAGIC, GET_BUF_RESV_SIZE(context), + &offset); + if (!head) { + fprintf(stderr, "No GCS context\n"); + return 1; + } + + gcs = (struct gcs_context *)head; + + /* Basic size validation is done in get_current_context() */ + + if (gcs->features_enabled != expected) { + fprintf(stderr, "Features enabled %llx but expected %lx\n", + gcs->features_enabled, expected); + return 1; + } + + if (gcs->gcspr != gcspr) { + fprintf(stderr, "Got GCSPR %llx but expected %lx\n", + gcs->gcspr, gcspr); + return 1; + } + + fprintf(stderr, "GCS context validated\n"); + td->pass = 1; + + return 0; +} + +struct tdescr tde = { + .name = "GCS basics", + .descr = "Validate a GCS signal context", + .feats_required = FEAT_GCS, + .timeout = 3, + .run = gcs_regs, +}; diff --git a/tools/testing/selftests/arm64/signal/testcases/gcs_write_fault.c b/tools/testing/selftests/arm64/signal/testcases/gcs_write_fault.c new file mode 100644 index 000000000000..126b1a294a29 --- /dev/null +++ b/tools/testing/selftests/arm64/signal/testcases/gcs_write_fault.c @@ -0,0 +1,67 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (C) 2023 ARM Limited + */ + +#include +#include +#include + +#include +#include + +#include "test_signals_utils.h" +#include "testcases.h" + +static uint64_t *gcs_page; + +#ifndef __NR_map_shadow_stack +#define __NR_map_shadow_stack 452 +#endif + +static bool alloc_gcs(struct tdescr *td) +{ + long page_size = sysconf(_SC_PAGE_SIZE); + + gcs_page = (void *)syscall(__NR_map_shadow_stack, 0, + page_size, 0); + if (gcs_page == MAP_FAILED) { + fprintf(stderr, "Failed to map %ld byte GCS: %d\n", + page_size, errno); + return false; + } + + return true; +} + +static int gcs_write_fault_trigger(struct tdescr *td) +{ + /* Verify that the page is readable (ie, not completely unmapped) */ + fprintf(stderr, "Read value 0x%lx\n", gcs_page[0]); + + /* A regular write should trigger a fault */ + gcs_page[0] = EINVAL; + + return 0; +} + +static int gcs_write_fault_signal(struct tdescr *td, siginfo_t *si, + ucontext_t *uc) +{ + ASSERT_GOOD_CONTEXT(uc); + + return 1; +} + + +struct tdescr tde = { + .name = "GCS write fault", + .descr = "Normal writes to a GCS segfault", + .feats_required = FEAT_GCS, + .timeout = 3, + .sig_ok = SIGSEGV, + .sanity_disabled = true, + .init = alloc_gcs, + .trigger = gcs_write_fault_trigger, + .run = gcs_write_fault_signal, +};