From patchwork Fri Dec 3 07:32:46 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Pengfei Xu X-Patchwork-Id: 12654435 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 C26F4C433F5 for ; Fri, 3 Dec 2021 07:32:10 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1378923AbhLCHfd (ORCPT ); Fri, 3 Dec 2021 02:35:33 -0500 Received: from mga09.intel.com ([134.134.136.24]:9200 "EHLO mga09.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1378931AbhLCHfc (ORCPT ); Fri, 3 Dec 2021 02:35:32 -0500 X-IronPort-AV: E=McAfee;i="6200,9189,10186"; a="236740527" X-IronPort-AV: E=Sophos;i="5.87,283,1631602800"; d="scan'208";a="236740527" Received: from orsmga008.jf.intel.com ([10.7.209.65]) by orsmga102.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 02 Dec 2021 23:32:08 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.87,283,1631602800"; d="scan'208";a="513607793" Received: from xpf.sh.intel.com ([10.239.182.112]) by orsmga008.jf.intel.com with ESMTP; 02 Dec 2021 23:32:06 -0800 From: Pengfei Xu To: Shuah Khan , linux-kselftest , linux-kernel Cc: Pengfei Xu , Heng Su , Hansen Dave , Luck Tony , Mehta Sohil , Chen Yu C , Andy Lutomirski Subject: [RFC PATCH v5 2/2] selftests/x86: add xsave test after process switch Date: Fri, 3 Dec 2021 15:32:46 +0800 Message-Id: <170f6221d53798f99cf00f0cd830c970289081d8.1638513720.git.pengfei.xu@intel.com> X-Mailer: git-send-email 2.27.0 In-Reply-To: References: MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-kselftest@vger.kernel.org It will change FPU, AVX2, AVX512, PKRU xstates before process switch test to ensure that the entire processing of these xstates works as expected. In order to ensure the above XSAVE content is not affected after process switch, this case tests that: 1. The xstates content of the child process should same as xstates of parent process. 2. The xstates content of the child process should not change after process switch back, even grandchild process cleaned up it's own XMM, YMM and ZMM xstates. Signed-off-by: Pengfei Xu --- tools/testing/selftests/x86/Makefile | 2 +- tools/testing/selftests/x86/xsave_fork_test.c | 127 ++++++++++++++++++ 2 files changed, 128 insertions(+), 1 deletion(-) create mode 100644 tools/testing/selftests/x86/xsave_fork_test.c diff --git a/tools/testing/selftests/x86/Makefile b/tools/testing/selftests/x86/Makefile index b51f02bc38c2..5b627ae5e385 100644 --- a/tools/testing/selftests/x86/Makefile +++ b/tools/testing/selftests/x86/Makefile @@ -18,7 +18,7 @@ TARGETS_C_32BIT_ONLY := entry_from_vm86 test_syscall_vdso unwind_vdso \ test_FCMOV test_FCOMI test_FISTTP \ vdso_restorer TARGETS_C_64BIT_ONLY := fsgsbase sysret_rip syscall_numbering \ - corrupt_xstate_header amx xsave_signal_handle + corrupt_xstate_header amx xsave_signal_handle xsave_fork_test # Some selftests require 32bit support enabled also on 64bit systems TARGETS_C_32BIT_NEEDED := ldt_gdt ptrace_syscall diff --git a/tools/testing/selftests/x86/xsave_fork_test.c b/tools/testing/selftests/x86/xsave_fork_test.c new file mode 100644 index 000000000000..00d1bfcfc6f7 --- /dev/null +++ b/tools/testing/selftests/x86/xsave_fork_test.c @@ -0,0 +1,127 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * It's for XSAVE fork test. + */ + +#define _GNU_SOURCE + +#include +#include +#include +#include +#include +#include +#include +#include + +#include "xsave_common.h" + +static unsigned char *xsave_buf0, *xsave_buf1, *xsave_buf2; +static int xsave_size, read_result[2]; +static const char *fork_test = "xsave fork for xsave context switch test"; + +void set_xstates(void) +{ + /* SDM XSAVE: misalignment to a 64-byte boundary will result in #GP */ + xsave_buf0 = aligned_alloc(64, xsave_size); + if (!xsave_buf0) + execution_failed("aligned_alloc xsave_buf0 failed\n"); + xsave_buf1 = aligned_alloc(64, xsave_size); + if (!xsave_buf1) + execution_failed("aligned_alloc xsave_buf1 failed\n"); + xsave_buf2 = aligned_alloc(64, xsave_size); + if (!xsave_buf2) + execution_failed("aligned_alloc xsave_buf2 failed\n"); + + populate_xstate_regs(); +} + +void clear_avx(void) +{ + asm volatile("vzeroall"); +} + +/* use fork to create pid and trigger context switch test */ +int test_fork(void) +{ + pid_t child; + int status, fd[2], result[2]; + const char *test_xsave_child = "Child xstate was same as parent"; + const char *test_process_swich = "Xstate after process switch was same"; + + /* Use pipe to transfer test result of child process to parent process */ + if (pipe(fd) < 0) + execution_failed("FAIL: create pipe failed\n"); + + XSAVE(xsave_buf0, XSAVE_TEST_MASK); + child = fork(); + if (child < 0) + execution_failed("fork failed\n"); + if (child == 0) { + XSAVE(xsave_buf1, XSAVE_TEST_MASK); + result[0] = compare_xsave_buf(xsave_buf0, xsave_buf1, xsave_size, + fork_test, NO_CHANGE); + close(fd[0]); + if (!write(fd[1], &result, sizeof(result))) + execution_failed("FAIL: write fd failed.\n"); + + XSAVE(xsave_buf1, XSAVE_TEST_MASK); + pid_t grandchild; + + /* fork grandchild will trigger process switching in child */ + grandchild = fork(); + if (grandchild == 0) { + ksft_print_msg("Grandchild pid:%d clean it's XMM YMM ZMM xstates\n", + getpid()); + clear_avx(); + return 0; + } + if (grandchild) + waitpid(grandchild, NULL, 0); + + /* After swich back to child process and check xstate */ + XSAVE(xsave_buf2, XSAVE_TEST_MASK); + ksft_print_msg("Child pid:%d check xstate after swtich back\n", + getpid()); + result[1] = compare_xsave_buf(xsave_buf1, xsave_buf2, xsave_size, + fork_test, NO_CHANGE); + if (!write(fd[1], &result, sizeof(result))) + execution_failed("FAIL: write fd failed.\n"); + + return 0; + } + + if (child) { + if (waitpid(child, &status, 0) != child || !WIFEXITED(status)) + ksft_test_result_fail("Child exit with error, status:0x%x\n", + status); + else { + ksft_print_msg("Parent pid:%d get results\n", getpid()); + close(fd[1]); + if (!read(fd[0], &read_result, sizeof(read_result))) + execution_failed("FAIL: read fd failed.\n"); + } + } + + ksft_set_plan(2); + check_result(read_result[0], test_xsave_child); + check_result(read_result[1], test_process_swich); + + return 0; +} + +int main(int argc, char *argv[]) +{ + cpu_set_t set; + + xsave_size = get_xsave_size(); + ksft_print_header(); + + CPU_ZERO(&set); + CPU_SET(0, &set); + + set_xstates(); + test_fork(); + + ksft_exit(!ksft_get_fail_cnt()); +}