From patchwork Mon Jul 24 12:46:18 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mark Brown X-Patchwork-Id: 13324651 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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id CD4F5C001DE for ; Mon, 24 Jul 2023 12:50:23 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 669018E0002; Mon, 24 Jul 2023 08:50:23 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 619B0900002; Mon, 24 Jul 2023 08:50:23 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 4BA768E0005; Mon, 24 Jul 2023 08:50:23 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0016.hostedemail.com [216.40.44.16]) by kanga.kvack.org (Postfix) with ESMTP id 3B0008E0002 for ; Mon, 24 Jul 2023 08:50:23 -0400 (EDT) Received: from smtpin14.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay06.hostedemail.com (Postfix) with ESMTP id 0D732B20C8 for ; Mon, 24 Jul 2023 12:50:23 +0000 (UTC) X-FDA: 81046488726.14.FC4A296 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by imf09.hostedemail.com (Postfix) with ESMTP id 1EE6314000B for ; Mon, 24 Jul 2023 12:50:20 +0000 (UTC) Authentication-Results: imf09.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=FxXy0+nf; dmarc=pass (policy=none) header.from=kernel.org; spf=pass (imf09.hostedemail.com: domain of broonie@kernel.org designates 139.178.84.217 as permitted sender) smtp.mailfrom=broonie@kernel.org ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1690203021; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=LPEExQ1Qk1Ez728TN65UkW7spefPs4z4cACz+EcOj8w=; b=Q9gXeeV1DKfJ5ywjJLjICqUbkKK3snlqYTGjSOzSUgAzKfr2hCtOuPNLTTbQEwc8p6rK4e DmBQdZyJj17r/krMGxVVB+dUTEJRxLRu9GBwPYxuMUDmBTeJpfIsuv7cs+G4//b9RWcPK1 zH1EBMK9ABCKOD0WPcXCTdySd1Wg66E= ARC-Authentication-Results: i=1; imf09.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=FxXy0+nf; dmarc=pass (policy=none) header.from=kernel.org; spf=pass (imf09.hostedemail.com: domain of broonie@kernel.org designates 139.178.84.217 as permitted sender) smtp.mailfrom=broonie@kernel.org ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1690203021; a=rsa-sha256; cv=none; b=WPzTDoQgLAr38XF30zTo0Bvv7RBd30oIWA0zzEV21fgl8KH9GXStGuyflAvbLOSMAXFVME Rf30uxcTeNTVkqqChb2tdZuIKuLYzHJ36pH/96IDgmGz5bGFmKQGKcEaoB6neRM+h9Qp/j /4+JqlrDp/Lrl/LngNiEwckAq4YMIAo= 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 5B7B461159; Mon, 24 Jul 2023 12:50:20 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id AE19AC433C7; Mon, 24 Jul 2023 12:50:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1690203019; bh=PDX/i4+fFmNinWArKmgCBD81AP/VqydBiUWqO2kyXWw=; h=From:Date:Subject:References:In-Reply-To:To:Cc:From; b=FxXy0+nfT98Opbzb3MyUz+BtkZmXTeyXRJBFJBXZkGEq+pk6x+ro/XAqRU7rCNNhV jykXMa4Wd9kYUX9NumwRN5uaaTjeC2hLJ5WuMdplRumE+1B5LHQRHf7f9Lli1lf4UL cu6vcjah6gv/CW4ZE8Sa+r9D4za1sOn8HbRe8KFK/mqmwLDmZSIvSJES2tOx6oS97V wzTydx8cwMAOnN36ErUWRfTKLRMbv8tRtP9Sglv8nKUodVto8j0l3NCMzLviyhBMby NPEFlXjK+od4N8fqavmgy/b7QziLMZSallylKi97pQUuQeIwheKB2CFlI8WGeevHhA 3PdTg6toJoh7Q== From: Mark Brown Date: Mon, 24 Jul 2023 13:46:18 +0100 Subject: [PATCH v2 31/35] kselftest/arm64: Add very basic GCS test program MIME-Version: 1.0 Message-Id: <20230724-arm64-gcs-v2-31-dc2c1d44c2eb@kernel.org> References: <20230724-arm64-gcs-v2-0-dc2c1d44c2eb@kernel.org> In-Reply-To: <20230724-arm64-gcs-v2-0-dc2c1d44c2eb@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-099c9 X-Developer-Signature: v=1; a=openpgp-sha256; l=12863; i=broonie@kernel.org; h=from:subject:message-id; bh=PDX/i4+fFmNinWArKmgCBD81AP/VqydBiUWqO2kyXWw=; b=owEBbQGS/pANAwAKASTWi3JdVIfQAcsmYgBkvnK5s4F26dClHtsRv7gKsv/4cmzaQ4WjiEO4cN26 f87F5UOJATMEAAEKAB0WIQSt5miqZ1cYtZ/in+ok1otyXVSH0AUCZL5yuQAKCRAk1otyXVSH0CBOB/ 9HDBmt9W+5APBJ6ecYRNvR8/bjOgN50IN3Sr93T9CgULfi0fI8E8mWb/wHwsUFJ74StiLlcPAuGpP4 2Sf6kyqk0wz06Qc7Wu8KvGD0OI7ZGFSVRnKQqqrKC2HekLvpLl5TtOLGJqw11w+WZdOV76mBYFO9D5 FIs2JRfn5agF2cmNG4FbLSVyJh1i1dxr/M5R4wBilTaBQZ2n9peMk9I61mRkwC8Os+eH+1wVEKvJJ/ ALvzm5DTOfuAcNewuonFo+USnzWulLigGPOlNsEelVH3EqkEsBO5KP6wAifURsL++5p1ym4MwD4TPQ 3zHJk0jEGFmB1Oynwj+kMTGZs60Xoh X-Developer-Key: i=broonie@kernel.org; a=openpgp; fpr=3F2568AAC26998F9E813A1C5C3F436CA30F5D8EB X-Rspamd-Queue-Id: 1EE6314000B X-Rspam-User: X-Rspamd-Server: rspam04 X-Stat-Signature: 5az1qwpktkrmwykxq5ecmt8az61hfnwa X-HE-Tag: 1690203020-697732 X-HE-Meta: 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 pfq0AqVr a8IsR4dgAWmhkY02DbiZhCg6wj0fp2qGzvkrIbMCYPuu7hDpwBiwuihulm1kAvySMKZqvvx30bdjIJNdxSph+gHQit8dfQNKgkUgjbIYWXrMVz3aFSEKj07ZxcXhhMrQievfwLE7L4qNOdqGBkZMFbJvx+dRt/0CAFp7iTIT10oN/TGrPP5OMtCb5lGV06yIhzV2t6tF3V5nP9+XtpPZdHcfW/i7jMLDc8FEHEXhkWu5xfsvq/NCbTX5N/lErjfsws1d7zt90N2xCIfztQfusOoUd2HuaGJhedmxu9rY2iZrfPKm21W240+eihIXq7oPvFtezukad/VqWedCIrDa30nHgQc5SE306MFNNe4QY5s59cEelZ5kJy00Z+Rbhg+U4dD7EBT8p6lQFrOuWP+7SWGGxwyNl7jMKkrAUYzlf836pbuQ= X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: This test program just covers the basic GCS ABI, covering aspects of the ABI as standalone features without attempting to integrate things. Signed-off-by: Mark Brown --- tools/testing/selftests/arm64/Makefile | 2 +- tools/testing/selftests/arm64/gcs/.gitignore | 1 + tools/testing/selftests/arm64/gcs/Makefile | 17 ++ tools/testing/selftests/arm64/gcs/basic-gcs.c | 351 ++++++++++++++++++++++++++ tools/testing/selftests/arm64/gcs/gcs-util.h | 87 +++++++ 5 files changed, 457 insertions(+), 1 deletion(-) diff --git a/tools/testing/selftests/arm64/Makefile b/tools/testing/selftests/arm64/Makefile index ace8b67fb22d..66877a879a9d 100644 --- a/tools/testing/selftests/arm64/Makefile +++ b/tools/testing/selftests/arm64/Makefile @@ -4,7 +4,7 @@ ARCH ?= $(shell uname -m 2>/dev/null || echo not) ifneq (,$(filter $(ARCH),aarch64 arm64)) -ARM64_SUBTARGETS ?= tags signal pauth fp mte bti abi +ARM64_SUBTARGETS ?= tags signal pauth fp mte bti abi gcs else ARM64_SUBTARGETS := endif diff --git a/tools/testing/selftests/arm64/gcs/.gitignore b/tools/testing/selftests/arm64/gcs/.gitignore new file mode 100644 index 000000000000..0e5e695ecba5 --- /dev/null +++ b/tools/testing/selftests/arm64/gcs/.gitignore @@ -0,0 +1 @@ +basic-gcs diff --git a/tools/testing/selftests/arm64/gcs/Makefile b/tools/testing/selftests/arm64/gcs/Makefile new file mode 100644 index 000000000000..322c40d25f2e --- /dev/null +++ b/tools/testing/selftests/arm64/gcs/Makefile @@ -0,0 +1,17 @@ +# SPDX-License-Identifier: GPL-2.0 +# Copyright (C) 2023 ARM Limited +# +# In order to avoid interaction with the toolchain and dynamic linker the +# portions of these tests that interact with the GCS are implemented using +# nolibc. +# + +TEST_GEN_PROGS := basic-gcs + +include ../../lib.mk + +$(OUTPUT)/basic-gcs: basic-gcs.c + $(CC) -g -fno-asynchronous-unwind-tables -fno-ident -s -Os -nostdlib \ + -static -include ../../../../include/nolibc/nolibc.h \ + -std=gnu99 -I../.. -g \ + -ffreestanding -Wall $^ -o $@ -lgcc diff --git a/tools/testing/selftests/arm64/gcs/basic-gcs.c b/tools/testing/selftests/arm64/gcs/basic-gcs.c new file mode 100644 index 000000000000..625258e00302 --- /dev/null +++ b/tools/testing/selftests/arm64/gcs/basic-gcs.c @@ -0,0 +1,351 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) 2023 ARM Limited. + */ + +#include +#include + +#include + +#include "kselftest.h" +#include "gcs-util.h" + +/* nolibc doesn't have sysconf(), just hard code the maximum */ +static size_t page_size = 65536; + +static __attribute__((noinline)) void valid_gcs_function(void) +{ + /* Do something the compiler can't optimise out */ + my_syscall1(__NR_prctl, PR_SVE_GET_VL); +} + +static inline int gcs_set_status(unsigned long mode) +{ + bool enabling = mode & PR_SHADOW_STACK_ENABLE; + int ret; + unsigned long new_mode; + + /* + * The prctl takes 1 argument but we need to ensure that the + * other 3 values passed in registers to the syscall are zero + * since the kernel validates them. + */ + ret = my_syscall5(__NR_prctl, PR_SET_SHADOW_STACK_STATUS, mode, + 0, 0, 0); + + if (ret == 0) { + ret = my_syscall5(__NR_prctl, PR_GET_SHADOW_STACK_STATUS, + &new_mode, 0, 0, 0); + if (ret == 0) { + if (new_mode != mode) { + ksft_print_msg("Mode set to %x not %x\n", + new_mode, mode); + ret = -EINVAL; + } + } else { + ksft_print_msg("Failed to validate mode: %d\n", ret); + } + + if (enabling != chkfeat_gcs()) { + ksft_print_msg("%senabled by prctl but %senabled in CHKFEAT\n", + enabling ? "" : "not ", + chkfeat_gcs() ? "" : "not "); + ret = -EINVAL; + } + } + + return ret; +} + +/* Try to read the status */ +static bool read_status(void) +{ + unsigned long state; + int ret; + + ret = my_syscall5(__NR_prctl, PR_GET_SHADOW_STACK_STATUS, + &state, 0, 0, 0); + if (ret != 0) { + ksft_print_msg("Failed to read state: %d\n", ret); + return false; + } + + return state & PR_SHADOW_STACK_ENABLE; +} + +/* Just a straight enable */ +static bool base_enable(void) +{ + int ret; + + ret = gcs_set_status(PR_SHADOW_STACK_ENABLE); + if (ret) { + ksft_print_msg("PR_SHADOW_STACK_ENABLE failed %d\n", ret); + return false; + } + + return true; +} + +/* Check we can read GCSPR_EL0 when GCS is enabled */ +static bool read_gcspr_el0(void) +{ + unsigned long *gcspr_el0; + + ksft_print_msg("GET GCSPR\n"); + gcspr_el0 = get_gcspr(); + ksft_print_msg("GCSPR_EL0 is %p\n", gcspr_el0); + + return true; +} + +/* Also allow writes to stack */ +static bool enable_writeable(void) +{ + int ret; + + ret = gcs_set_status(PR_SHADOW_STACK_ENABLE | PR_SHADOW_STACK_WRITE); + if (ret) { + ksft_print_msg("PR_SHADOW_STACK_ENABLE writeable failed: %d\n", ret); + return false; + } + + ret = gcs_set_status(PR_SHADOW_STACK_ENABLE); + if (ret) { + ksft_print_msg("failed to restore plain enable %d\n", ret); + return false; + } + + return true; +} + +/* Also allow writes to stack */ +static bool enable_push_pop(void) +{ + int ret; + + ret = gcs_set_status(PR_SHADOW_STACK_ENABLE | PR_SHADOW_STACK_PUSH); + if (ret) { + ksft_print_msg("PR_SHADOW_STACK_ENABLE with push failed: %d\n", + ret); + return false; + } + + ret = gcs_set_status(PR_SHADOW_STACK_ENABLE); + if (ret) { + ksft_print_msg("failed to restore plain enable %d\n", ret); + return false; + } + + return true; +} + +/* Enable GCS and allow everything */ +static bool enable_all(void) +{ + int ret; + + ret = gcs_set_status(PR_SHADOW_STACK_ENABLE | PR_SHADOW_STACK_PUSH | + PR_SHADOW_STACK_WRITE); + if (ret) { + ksft_print_msg("PR_SHADOW_STACK_ENABLE with everything failed: %d\n", + ret); + return false; + } + + ret = gcs_set_status(PR_SHADOW_STACK_ENABLE); + if (ret) { + ksft_print_msg("failed to restore plain enable %d\n", ret); + return false; + } + + return true; +} + +static bool enable_invalid(void) +{ + int ret = gcs_set_status(ULONG_MAX); + if (ret == 0) { + ksft_print_msg("GCS_SET_STATUS %lx succeeded\n", ULONG_MAX); + return false; + } + + return true; +} + +/* Map a GCS */ +static bool map_guarded_stack(void) +{ + int ret; + uint64_t *buf; + uint64_t expected_cap; + int elem; + bool pass = true; + + buf = (void *)my_syscall3(__NR_map_shadow_stack, 0, page_size, 0); + if (buf == MAP_FAILED) { + ksft_print_msg("Failed to map %d byte GCS: %d\n", + page_size, errno); + return false; + } + ksft_print_msg("Mapped GCS at %p-%p\n", buf, + (uint64_t)buf + page_size); + + /* The top of the newly allocated region should be 0 */ + elem = (page_size / sizeof(uint64_t)) - 1; + if (buf[elem]) { + ksft_print_msg("Last entry is 0x%lx not 0x0\n", buf[elem]); + pass = false; + } + + /* Then a valid cap token */ + elem--; + expected_cap = ((uint64_t)buf + page_size - 16); + expected_cap &= GCS_CAP_ADDR_MASK; + expected_cap |= GCS_CAP_VALID_TOKEN; + if (buf[elem] != expected_cap) { + ksft_print_msg("Cap entry is 0x%lx not 0x%lx\n", + buf[elem], expected_cap); + pass = false; + } + ksft_print_msg("cap token is 0x%lx\n", buf[elem]); + + /* The rest should be zeros */ + for (elem = 0; elem < page_size / sizeof(uint64_t) - 2; elem++) { + if (!buf[elem]) + continue; + ksft_print_msg("GCS slot %d is 0x%lx not 0x0\n", + elem, buf[elem]); + pass = false; + } + + ret = munmap(buf, page_size); + if (ret != 0) { + ksft_print_msg("Failed to unmap %d byte GCS: %d\n", + page_size, errno); + pass = false; + } + + return pass; +} + +/* A fork()ed process can run */ +static bool test_fork(void) +{ + unsigned long child_mode; + int ret, status; + pid_t pid; + bool pass = true; + + pid = fork(); + if (pid == -1) { + ksft_print_msg("fork() failed: %d\n", errno); + pass = false; + goto out; + } + if (pid == 0) { + /* In child, make sure we can call a function, read + * the GCS pointer and status and then exit */ + valid_gcs_function(); + get_gcspr(); + + ret = my_syscall5(__NR_prctl, PR_GET_SHADOW_STACK_STATUS, + &child_mode, 0, 0, 0); + if (ret == 0 && !(child_mode & PR_SHADOW_STACK_ENABLE)) { + ksft_print_msg("GCS not enabled in child\n"); + ret = -EINVAL; + } + + exit(ret); + } + + /* + * In parent, check we can still do function calls then block + * for the child. + */ + valid_gcs_function(); + + ksft_print_msg("Waiting for child %d\n", pid); + + ret = waitpid(pid, &status, 0); + if (ret == -1) { + ksft_print_msg("Failed to wait for child: %d\n", + errno); + return false; + } + + if (!WIFEXITED(status)) { + ksft_print_msg("Child exited due to signal %d\n", + WTERMSIG(status)); + pass = false; + } else { + if (WEXITSTATUS(status)) { + ksft_print_msg("Child exited with status %d\n", + WEXITSTATUS(status)); + pass = false; + } + } + +out: + + return pass; +} + +typedef bool (*gcs_test)(void); + +static struct { + char *name; + gcs_test test; + bool needs_enable; +} tests[] = { + { "read_status", read_status }, + { "base_enable", base_enable, true }, + { "read_gcspr_el0", read_gcspr_el0 }, + { "enable_writeable", enable_writeable, true }, + { "enable_push_pop", enable_push_pop, true }, + { "enable_all", enable_all, true }, + { "enable_invalid", enable_invalid, true }, + { "map_guarded_stack", map_guarded_stack }, + { "fork", test_fork }, +}; + +int main(void) +{ + int i, ret; + unsigned long gcs_mode; + + ksft_print_header(); + + /* + * We don't have getauxval() with nolibc so treat a failure to + * read GCS state as a lack of support and skip. + */ + ret = my_syscall5(__NR_prctl, PR_GET_SHADOW_STACK_STATUS, + &gcs_mode, 0, 0, 0); + if (ret != 0) + ksft_exit_skip("Failed to read GCS state: %d\n", ret); + + if (!(gcs_mode & PR_SHADOW_STACK_ENABLE)) { + gcs_mode = PR_SHADOW_STACK_ENABLE; + ret = my_syscall5(__NR_prctl, PR_SET_SHADOW_STACK_STATUS, + gcs_mode, 0, 0, 0); + if (ret != 0) + ksft_exit_fail_msg("Failed to enable GCS: %d\n", ret); + } + + ksft_set_plan(ARRAY_SIZE(tests)); + + for (i = 0; i < ARRAY_SIZE(tests); i++) { + ksft_test_result((*tests[i].test)(), "%s\n", tests[i].name); + } + + /* One last test: disable GCS, we can do this one time */ + my_syscall5(__NR_prctl, PR_SET_SHADOW_STACK_STATUS, 0, 0, 0, 0); + if (ret != 0) + ksft_print_msg("Failed to disable GCS: %d\n", ret); + + ksft_finished(); + + return 0; +} diff --git a/tools/testing/selftests/arm64/gcs/gcs-util.h b/tools/testing/selftests/arm64/gcs/gcs-util.h new file mode 100644 index 000000000000..c517f1a710c5 --- /dev/null +++ b/tools/testing/selftests/arm64/gcs/gcs-util.h @@ -0,0 +1,87 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * Copyright (C) 2023 ARM Limited. + */ + +#ifndef GCS_UTIL_H +#define GCS_UTIL_H + +#include + +#ifndef __NR_map_shadow_stack +#define __NR_map_shadow_stack 452 +#endif + +#ifndef __NR_prctl +#define __NR_prctl 167 +#endif + +/* Shadow Stack/Guarded Control Stack interface */ +#define PR_GET_SHADOW_STACK_STATUS 71 +#define PR_SET_SHADOW_STACK_STATUS 72 +#define PR_LOCK_SHADOW_STACK_STATUS 73 + +# define PR_SHADOW_STACK_ENABLE (1UL << 0) +# define PR_SHADOW_STACK_WRITE (1UL << 1) +# define PR_SHADOW_STACK_PUSH (1UL << 2) + +#define PR_SHADOW_STACK_ALL_MODES \ + PR_SHADOW_STACK_ENABLE | PR_SHADOW_STACK_WRITE | PR_SHADOW_STACK_PUSH + +#define GCS_CAP_ADDR_MASK (0xfffffffffffff000UL) +#define GCS_CAP_TOKEN_MASK (0x0000000000000fffUL) +#define GCS_CAP_VALID_TOKEN 1 +#define GCS_CAP_IN_PROGRESS_TOKEN 5 + +#define GCS_CAP(x) (((unsigned long)(x) & GCS_CAP_ADDR_MASK) | \ + GCS_CAP_VALID_TOKEN) + +static inline unsigned long *get_gcspr(void) +{ + unsigned long *gcspr; + + asm volatile( + "mrs %0, S3_3_C2_C5_1" + : "=r" (gcspr) + : + : "cc"); + + return gcspr; +} + +static inline void __attribute__((always_inline)) gcsss1(unsigned long *Xt) +{ + asm volatile ( + "sys #3, C7, C7, #2, %0\n" + : + : "rZ" (Xt) + : "memory"); +} + +static inline unsigned long __attribute__((always_inline)) *gcsss2(void) +{ + unsigned long *Xt; + + asm volatile( + "SYSL %0, #3, C7, C7, #3\n" + : "=r" (Xt) + : + : "memory"); + + return Xt; +} + +static inline bool chkfeat_gcs(void) +{ + register long val __asm__ ("x16") = 1; + + /* CHKFEAT x16 */ + asm volatile( + "hint #0x28\n" + : "=r" (val) + : "r" (val)); + + return val != 1; +} + +#endif