From patchwork Tue Nov 14 20:05:58 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mark Brown X-Patchwork-Id: 743896 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 E264135EEA; Tue, 14 Nov 2023 20:06:47 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="COcQPXbg" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 1DABDC433CA; Tue, 14 Nov 2023 20:06:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1699992407; bh=E/vO68ZFg6z/6OFrFC7xPTTrAHCnKC1HTh6WooalFG0=; h=From:Date:Subject:References:In-Reply-To:To:Cc:From; b=COcQPXbgQRtRh6McXlLmwmXao6NZB3DoRessUOEzmGfXy4Q/yfYUiqe2WOLh/IYGF FMBnikyOgbZ4guVGrh4thejR7lpM9/J7elIeMvqn0TvaqPkguJ+s3Aq37l4LuqxRFC v4p5MmzIlI1cXY3d+ExzvWO6rv1/BAv2iZM/SxWfFH+irRYyhcVt5iA5XOIAtofqZs ff55nzUXFCkjKqaW3ENaYA+/zyjpH1diIaH8FSe0+DzEzNzf12qZRNKc9wraAurRpB QTq0/Y8N6T3asG2FNY6JVFVGgPdEAYk1sGStNyZsJR1xaOjloUaEo2iNq1d878F5q1 KPBFNtezCOfpA== From: Mark Brown Date: Tue, 14 Nov 2023 20:05:58 +0000 Subject: [PATCH RFC RFT v2 5/5] kselftest/clone3: Test shadow stack support Precedence: bulk X-Mailing-List: linux-kselftest@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Message-Id: <20231114-clone3-shadow-stack-v2-5-b613f8681155@kernel.org> References: <20231114-clone3-shadow-stack-v2-0-b613f8681155@kernel.org> In-Reply-To: <20231114-clone3-shadow-stack-v2-0-b613f8681155@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 , Kees Cook , jannh@google.com, bsegall@google.com, 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=4655; i=broonie@kernel.org; h=from:subject:message-id; bh=E/vO68ZFg6z/6OFrFC7xPTTrAHCnKC1HTh6WooalFG0=; b=owEBbQGS/pANAwAKASTWi3JdVIfQAcsmYgBlU9Mw/E0ZsNXT9pAEZkYqPqXgi0HGwFTiejBMba7Z 6cP6PmaJATMEAAEKAB0WIQSt5miqZ1cYtZ/in+ok1otyXVSH0AUCZVPTMAAKCRAk1otyXVSH0LQGB/ 4oDg/SgcY9WyortMyVY5pGTeVD+7/87/hOdY7hfIp+F1K7NuGnb1VAshA9GDrQrRrVDJR33MztYPws ERtdrqnCijOhMif91Jz0Mb6PPxhuPwdQM2wrWk3v7RpgcOyxMN0RaDlVwz4cfhfT8lM1btzDn+R8gP lv1fW6naRVaEBk1u+XByiBjDcNuC2gN6PnxA2uviZWaJEfRitQhRtzZLzcS7JF7G/LDzK9DX985Qcp XKNXyEOsQRryZb01iDaU7uZElG619LThNkspj0Ssw4LBsC1LbumQi+5yiwNW1+WR1Ms0PvU5OPq8JD Gq2E+E1TMJzFmDyydw6e59q55JmVey X-Developer-Key: i=broonie@kernel.org; a=openpgp; fpr=3F2568AAC26998F9E813A1C5C3F436CA30F5D8EB 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 | 68 +++++++++++++++++++++++ tools/testing/selftests/clone3/clone3_selftests.h | 7 +++ 2 files changed, 75 insertions(+) diff --git a/tools/testing/selftests/clone3/clone3.c b/tools/testing/selftests/clone3/clone3.c index 6adbfd14c841..10e0487c402a 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 +22,9 @@ #include "../kselftest.h" #include "clone3_selftests.h" +static bool shadow_stack_supported; +static size_t max_supported_args_size; + enum test_mode { CLONE3_ARGS_NO_TEST, CLONE3_ARGS_ALL_0, @@ -28,6 +32,7 @@ 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, }; typedef bool (*filter_function)(void); @@ -44,6 +49,27 @@ struct test { filter_function filter; }; +#ifndef __NR_map_shadow_stack +#define __NR_map_shadow_stack 453 +#endif + +static void test_shadow_stack_supported(void) +{ + long shadow_stack; + + 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; + + munmap((void *)shadow_stack, getpagesize()); + } +} + static int call_clone3(uint64_t flags, size_t size, enum test_mode test_mode) { struct __clone_args args = { @@ -89,6 +115,9 @@ 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_size = getpagesize(); + break; } memcpy(&args_ext.args, &args, sizeof(struct __clone_args)); @@ -179,6 +208,26 @@ static bool no_timenamespace(void) return true; } +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; @@ -322,6 +371,24 @@ 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 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[]) @@ -332,6 +399,7 @@ 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 3d2663fe50ba..2e06127091f5 100644 --- a/tools/testing/selftests/clone3/clone3_selftests.h +++ b/tools/testing/selftests/clone3/clone3_selftests.h @@ -31,6 +31,13 @@ struct __clone_args { __aligned_u64 set_tid; __aligned_u64 set_tid_size; __aligned_u64 cgroup; +#ifndef CLONE_ARGS_SIZE_VER2 +#define CLONE_ARGS_SIZE_VER2 88 /* sizeof third published struct */ +#endif + __aligned_u64 shadow_stack_size; +#ifndef CLONE_ARGS_SIZE_VER3 +#define CLONE_ARGS_SIZE_VER3 96 /* sizeof fourth published struct */ +#endif }; static pid_t sys_clone3(struct __clone_args *args, size_t size)