From patchwork Mon Oct 23 13:20:44 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mark Brown X-Patchwork-Id: 737415 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 276D8C001E0 for ; Mon, 23 Oct 2023 13:33:10 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233404AbjJWNdJ (ORCPT ); Mon, 23 Oct 2023 09:33:09 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46890 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233207AbjJWNdE (ORCPT ); Mon, 23 Oct 2023 09:33:04 -0400 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5BD092D6B; Mon, 23 Oct 2023 06:23:59 -0700 (PDT) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 3D217C433C9; Mon, 23 Oct 2023 13:23:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1698067439; bh=puDfEO1kotD4qFSC3EfqcfkBLrETnjNBFvX+npWIo7Q=; h=From:Date:Subject:References:In-Reply-To:To:Cc:From; b=vBUUwq+llRi1d+VXUlq4rIne0cNQFC9mBVdsJRmxA6hw1zuo4pa8pz5tFLgRvfIMa AApvDuCZMsviwORUf7q917sqJVGET4k73uK0lHCCy4o8D9qx5GwLpZZwBKkky7XwCK Uku+f6rp+Ukxor9ASvVVOoHHHI2+EFa5ecUAhjDh1hRkjr86MuN2DcRdCQmj011eG+ JueoVwWNcgb5Xq8A51ihzweh8u0tsXmPGoEwH4zgrg82Y1XtJbs8v7gMSvUtBjsXhq 2FBqqm+CfGqRehD9XcYS+C6ls2HtQMWMh0+hfzgiAJ2lW8Z9ebWN4bmdYxhbbKGfxZ oXc1+uktT9USg== From: Mark Brown Date: Mon, 23 Oct 2023 14:20:44 +0100 Subject: [PATCH RFC RFT 5/5] kselftest/clone3: Test shadow stack support MIME-Version: 1.0 Message-Id: <20231023-clone3-shadow-stack-v1-5-d867d0b5d4d0@kernel.org> References: <20231023-clone3-shadow-stack-v1-0-d867d0b5d4d0@kernel.org> In-Reply-To: <20231023-clone3-shadow-stack-v1-0-d867d0b5d4d0@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 , 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=5429; i=broonie@kernel.org; h=from:subject:message-id; bh=puDfEO1kotD4qFSC3EfqcfkBLrETnjNBFvX+npWIo7Q=; b=owEBbQGS/pANAwAKASTWi3JdVIfQAcsmYgBlNnPGxljfEiyeibQJM6yYflz/X64pYKiaOUmyiJKa TnfCRYOJATMEAAEKAB0WIQSt5miqZ1cYtZ/in+ok1otyXVSH0AUCZTZzxgAKCRAk1otyXVSH0KSEB/ 403D86ruPvelfqkNIt6c/l8os/uTJdhOhCAE7zQCqlEgXrWHHmDNSbag3fzY2TseKC4cjC0u4KjcBS FEpJ2Jq9+VlO2yBeJKmMOPvHorf9snbL+rrfzNBNRXYW4QyEBlUtp+iA/eE+6tiZD8ukp6p3oAQ1Se cy6dJmjs7rBkA/9tu1oI7ORqSu+sRXjn6xTY2H/AYrOc2F9GDiEClE1CRMglM1CxEDzqb7zE+e4nk+ jH2flJfgkHQK9eVFgko1GPZblC1zaVqhep54grPsBSoWq5LajKx77sfLZ2CIhyEQlUt0lQzgu1yciW weMEQgloUcc9nBdW3xmbj/nMiwdjKe X-Developer-Key: i=broonie@kernel.org; a=openpgp; fpr=3F2568AAC26998F9E813A1C5C3F436CA30F5D8EB Precedence: bulk List-ID: X-Mailing-List: linux-kselftest@vger.kernel.org Add basic test coverage for specifying the shadow stack for a newly created thread via clone3(), including coverage of the newly extended argument structure. We detect support for shadow stacks on the running system by attempting to allocate a shadow stack page during initialisation using map_shadow_stack(). Signed-off-by: Mark Brown --- tools/testing/selftests/clone3/clone3.c | 97 +++++++++++++++++++++++ tools/testing/selftests/clone3/clone3_selftests.h | 5 ++ 2 files changed, 102 insertions(+) diff --git a/tools/testing/selftests/clone3/clone3.c b/tools/testing/selftests/clone3/clone3.c index f1802db82e4e..33c35fdfcdfc 100644 --- a/tools/testing/selftests/clone3/clone3.c +++ b/tools/testing/selftests/clone3/clone3.c @@ -11,6 +11,7 @@ #include #include #include +#include #include #include #include @@ -21,6 +22,10 @@ #include "../kselftest.h" #include "clone3_selftests.h" +static bool shadow_stack_supported; +static __u64 shadow_stack; +static size_t max_supported_args_size; + enum test_mode { CLONE3_ARGS_NO_TEST, CLONE3_ARGS_ALL_0, @@ -28,6 +33,9 @@ enum test_mode { CLONE3_ARGS_INVAL_EXIT_SIGNAL_NEG, CLONE3_ARGS_INVAL_EXIT_SIGNAL_CSIG, CLONE3_ARGS_INVAL_EXIT_SIGNAL_NSIG, + CLONE3_ARGS_SHADOW_STACK, + CLONE3_ARGS_SHADOW_STACK_SIZE_ONLY, + CLONE3_ARGS_SHADOW_STACK_POINTER_ONLY, }; typedef bool (*filter_function)(void); @@ -44,6 +52,28 @@ struct test { filter_function filter; }; +#ifndef __NR_map_shadow_stack +#define __NR_map_shadow_stack 453 +#endif + +static void test_shadow_stack_supported(void) +{ + shadow_stack = syscall(__NR_map_shadow_stack, 0, getpagesize(), 0); + if (shadow_stack == -1) { + ksft_print_msg("map_shadow_stack() not supported\n"); + } else if ((void *)shadow_stack == MAP_FAILED) { + ksft_print_msg("Failed to map shadow stack\n"); + } else { + ksft_print_msg("Shadow stack supportd\n"); + shadow_stack_supported = true; + } + + /* Dummy stack to use for validating error checks */ + if (!shadow_stack_supported) { + shadow_stack = (__u64)malloc(getpagesize()); + } +} + static int call_clone3(uint64_t flags, size_t size, enum test_mode test_mode) { struct __clone_args args = { @@ -89,6 +119,16 @@ static int call_clone3(uint64_t flags, size_t size, enum test_mode test_mode) case CLONE3_ARGS_INVAL_EXIT_SIGNAL_NSIG: args.exit_signal = 0x00000000000000f0ULL; break; + case CLONE3_ARGS_SHADOW_STACK: + args.shadow_stack = shadow_stack; + args.shadow_stack_size = getpagesize(); + break; + case CLONE3_ARGS_SHADOW_STACK_SIZE_ONLY: + args.shadow_stack_size = getpagesize(); + break; + case CLONE3_ARGS_SHADOW_STACK_POINTER_ONLY: + args.shadow_stack = shadow_stack; + break; } memcpy(&args_ext.args, &args, sizeof(struct __clone_args)); @@ -167,6 +207,26 @@ static bool not_root(void) return false; } +static bool have_shadow_stack(void) +{ + if (shadow_stack_supported) { + ksft_print_msg("Shadow stack supported\n"); + return true; + } + + return false; +} + +static bool no_shadow_stack(void) +{ + if (!shadow_stack_supported) { + ksft_print_msg("Shadow stack not supported\n"); + return true; + } + + return false; +} + static size_t page_size_plus_8(void) { return getpagesize() + 8; @@ -309,6 +369,42 @@ static const struct test tests[] = { .expected = -EINVAL, .test_mode = CLONE3_ARGS_NO_TEST, }, + { + .name = "Shadow stack on system with shadow stack", + .flags = 0, + .size = 0, + .expected = 0, + .e2big_valid = true, + .test_mode = CLONE3_ARGS_SHADOW_STACK, + .filter = no_shadow_stack, + }, + { + .name = "Shadow stack with only size specified", + .flags = 0, + .size = 0, + .expected = -EINVAL, + .e2big_valid = true, + .test_mode = CLONE3_ARGS_SHADOW_STACK_SIZE_ONLY, + .filter = no_shadow_stack, + }, + { + .name = "Shadow stack with only pointer specified", + .flags = 0, + .size = 0, + .expected = -EINVAL, + .e2big_valid = true, + .test_mode = CLONE3_ARGS_SHADOW_STACK_POINTER_ONLY, + .filter = no_shadow_stack, + }, + { + .name = "Shadow stack on system without shadow stack", + .flags = 0, + .size = 0, + .expected = -EINVAL, + .e2big_valid = true, + .test_mode = CLONE3_ARGS_SHADOW_STACK, + .filter = have_shadow_stack, + }, }; int main(int argc, char *argv[]) @@ -319,6 +415,7 @@ int main(int argc, char *argv[]) ksft_print_header(); ksft_set_plan(ARRAY_SIZE(tests)); test_clone3_supported(); + test_shadow_stack_supported(); for (i = 0; i < ARRAY_SIZE(tests); i++) test_clone3(&tests[i]); diff --git a/tools/testing/selftests/clone3/clone3_selftests.h b/tools/testing/selftests/clone3/clone3_selftests.h index e81ffaaee02b..a77db460211b 100644 --- a/tools/testing/selftests/clone3/clone3_selftests.h +++ b/tools/testing/selftests/clone3/clone3_selftests.h @@ -43,6 +43,11 @@ struct __clone_args { __aligned_u64 cgroup; #ifndef CLONE_ARGS_SIZE_VER2 #define CLONE_ARGS_SIZE_VER2 88 /* sizeof third published struct */ +#endif + __aligned_u64 shadow_stack; + __aligned_u64 shadow_stack_size; +#ifndef CLONE_ARGS_SIZE_VER3 +#define CLONE_ARGS_SIZE_VER3 104 /* sizeof fourth published struct */ #endif };