From patchwork Tue Jun 25 14:58:05 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mark Brown X-Patchwork-Id: 13711401 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 5796B17C7D4; Tue, 25 Jun 2024 15:05:27 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1719327927; cv=none; b=SCGPIjmCZXs80Dlxkksm3KDxxo5PgyLsflJPAPHoTIy+xjU2BsZIkOCe/646vMG9G3eDuGbn93I6va9Y3QqMepETakCFMWk5mf08QvnKfFaXZqnb3GMV82mb5u5qhcfZlH1Ffclu3m0umtl9vpf2wOfH/Vwuc8URLkAkMxG7F0Y= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1719327927; c=relaxed/simple; bh=6kf8vUeE2/3/9q62BhJqQa6tQ8qTDalv3nPeOQkuUQk=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=VwEu13vYAxlaqpA4UL7o2nfA0HKjnqcfBe49rIbGr9FbMIbxtWRRERrqYHExA5vhNGzq+cDkowr1uf0X+cbrHud/o/hK4ZBp15yLu6Mszok2UNrLX9+USPbF0HzTe40+ybp3fUc+B1dItS+AF8NH+XS8O1XcJrCEbM1ThMpw90s= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=cNEK665H; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="cNEK665H" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 04C6CC4AF0A; Tue, 25 Jun 2024 15:05:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1719327927; bh=6kf8vUeE2/3/9q62BhJqQa6tQ8qTDalv3nPeOQkuUQk=; h=From:Date:Subject:References:In-Reply-To:To:Cc:From; b=cNEK665HSoWXVRXSv18N/8iIDoMvaOalTwGw1FCahJt7YskWm9Y+nm8VEilBD37Yx apZf6tKF0pjx7ZoKIxnU2+Ovb3D8/5Fss3/ONFtWcXF794jCawr2rsWg8uXDeQkedv W5OLaMX8coojfSEIejBKEryiOI+WXYyR8hKCzAOTzFgiwHshqGqKG1qLTeNvkrB+zs w1hWkRvhuVdqooQQ9FgW2/rGxseL3d7lO3DqR5lcKGigMzxen2g5MkJOB8Tn8SINga IBlrwnKXI1caWMQHxbaxOgdjg7uJbFXHU0HjlnJx8aUJTFa0IP+kdt8oTY8v9suHwN ImvUadueEf9JA== From: Mark Brown Date: Tue, 25 Jun 2024 15:58:05 +0100 Subject: [PATCH v9 37/39] kselftest/arm64: Add GCS signal tests Precedence: bulk X-Mailing-List: linux-kselftest@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Message-Id: <20240625-arm64-gcs-v9-37-0f634469b8f0@kernel.org> References: <20240625-arm64-gcs-v9-0-0f634469b8f0@kernel.org> In-Reply-To: <20240625-arm64-gcs-v9-0-0f634469b8f0@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 , Shuah Khan , "Rick P. Edgecombe" , Deepak Gupta , Ard Biesheuvel , Szabolcs Nagy , Kees Cook Cc: "H.J. Lu" , Paul Walmsley , Palmer Dabbelt , Albert Ou , Florian Weimer , Christian Brauner , Thiago Jung Bauermann , Ross Burton , 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 0.14-dev-d4707 X-Developer-Signature: v=1; a=openpgp-sha256; l=7642; i=broonie@kernel.org; h=from:subject:message-id; bh=6kf8vUeE2/3/9q62BhJqQa6tQ8qTDalv3nPeOQkuUQk=; b=owEBbQGS/pANAwAKASTWi3JdVIfQAcsmYgBmetuPquVxjSFARwh+scwwy3+t5W9RXsUl4EkCHnWu c0ZvgoWJATMEAAEKAB0WIQSt5miqZ1cYtZ/in+ok1otyXVSH0AUCZnrbjwAKCRAk1otyXVSH0PtVB/ 9TvfqwtKkWnWEXfy8Tnf8krx90zOIcw9m8P/csKWQ31MXOWRpAX9mZuHvU/8jsHXeN+b1FIAllWWdm PhaQ+A3IE1PTOE8Fo99JiDEIT4vYY2VI/WNVd2a30nUPGArQ3bbxOb2tyS8lBF1xLLPfER1PEr8Qwt iu3M2YpArb0T0/OHemiKW7nA3BDRJTZoJxqESvrWWlaTVyFJLJbmBvQcLkB41eHt+JZt89HvPmKp/V iU/eVP4CXmBomCKyS4fdjkt9ncgbPxFKeL0QjUuIJo1DOFWcgLXMvJDY95DWqjnXyRmOKQ4Rh6SMB/ 4MdEc5KnMWmWRjF68+DhFr/M0IGmCD X-Developer-Key: i=broonie@kernel.org; a=openpgp; fpr=3F2568AAC26998F9E813A1C5C3F436CA30F5D8EB 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. Reviewed-by: Thiago Jung Bauermann 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 | 62 +++++++++++++++ .../selftests/arm64/signal/testcases/gcs_frame.c | 88 ++++++++++++++++++++++ .../arm64/signal/testcases/gcs_write_fault.c | 67 ++++++++++++++++ 5 files changed, 228 insertions(+) diff --git a/tools/testing/selftests/arm64/signal/.gitignore b/tools/testing/selftests/arm64/signal/.gitignore index 1ce5b5eac386..75d691c13207 100644 --- a/tools/testing/selftests/arm64/signal/.gitignore +++ b/tools/testing/selftests/arm64/signal/.gitignore @@ -2,6 +2,7 @@ mangle_* fake_sigreturn_* fpmr_* +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 1e80808ee105..36fc12b3cd60 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 @@ -47,6 +48,15 @@ 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..6228448b2ae7 --- /dev/null +++ b/tools/testing/selftests/arm64/signal/testcases/gcs_exception_fault.c @@ -0,0 +1,62 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (C) 2023 ARM Limited + */ + +#include +#include +#include + +#include +#include + +#include "test_signals_utils.h" +#include "testcases.h" + +/* + * We should get this from asm/siginfo.h but the testsuite is being + * clever with redefining siginfo_t. + */ +#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..b405d82321da --- /dev/null +++ b/tools/testing/selftests/arm64/signal/testcases/gcs_frame.c @@ -0,0 +1,88 @@ +// 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; + uint64_t *u64_val; + 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; + } + + /* Ensure that the signal restore token was consumed */ + u64_val = (uint64_t *)get_gcspr_el0() + 1; + if (*u64_val) { + fprintf(stderr, "GCS value at %p is %lx not 0\n", + u64_val, *u64_val); + 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..faeabb18c4b2 --- /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 453 +#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, +};