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 7B9A5C25B50 for ; Mon, 23 Jan 2023 22:06:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232717AbjAWWGZ (ORCPT ); Mon, 23 Jan 2023 17:06:25 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50570 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232621AbjAWWGK (ORCPT ); Mon, 23 Jan 2023 17:06:10 -0500 Received: from mga09.intel.com (mga09.intel.com [134.134.136.24]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1B86338E93 for ; Mon, 23 Jan 2023 14:05:43 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1674511543; x=1706047543; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=+tHZ3UxGi6IqVb4/dqBwv5+3olZFm7fLyt/mIZ12PcU=; b=EAFaYFgLSvCmFg15wpP9kEZi0uLWImaR83btNs81LVdPGPJ0hbMyYm4N zPCw7vdhMzKcI8MshSJYYkpm03PANjmPwCEFyreLyfV5p1yYldd/8Onxh HoltH/0ZXvm0F1bwXGgS/n2cVyQeNaQRYXitlGGkiNfEYuJyjNbr43Wt9 6jRpcKs+ixGgjA/Np5vZJN1RtjmhfnQyb6dKcu5NpDyqFYZ/KcaOlZnOB c7ziYNJR7hO2xWdIQpMvP2bCEBsjn+wCVBRx4XzKOdZFvu87h+pXvmgYM f+0xZoQ7+oaYKjEoAHX1PhkRqCySXt+IlNM/iOM8UxffkOMq4ILqXeUAC g==; X-IronPort-AV: E=McAfee;i="6500,9779,10599"; a="327422009" X-IronPort-AV: E=Sophos;i="5.97,240,1669104000"; d="scan'208";a="327422009" Received: from orsmga002.jf.intel.com ([10.7.209.21]) by orsmga102.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 23 Jan 2023 14:05:33 -0800 X-IronPort-AV: E=McAfee;i="6500,9779,10599"; a="661878126" X-IronPort-AV: E=Sophos;i="5.97,240,1669104000"; d="scan'208";a="661878126" Received: from ssauty-mobl1.ger.corp.intel.com (HELO box.shutemov.name) ([10.249.46.171]) by orsmga002-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 23 Jan 2023 14:05:26 -0800 Received: by box.shutemov.name (Postfix, from userid 1000) id BCB35109B84; Tue, 24 Jan 2023 01:05:03 +0300 (+03) From: "Kirill A. Shutemov" To: Dave Hansen , Andy Lutomirski , Peter Zijlstra Cc: x86@kernel.org, Kostya Serebryany , Andrey Ryabinin , Andrey Konovalov , Alexander Potapenko , Taras Madan , Dmitry Vyukov , "H . J . Lu" , Andi Kleen , Rick Edgecombe , Bharata B Rao , Jacob Pan , Ashok Raj , Linus Torvalds , linux-mm@kvack.org, linux-kernel@vger.kernel.org, Weihong Zhang , "Kirill A . Shutemov" Subject: [PATCHv15 15/17] selftests/x86/lam: Add inherit test cases for linear-address masking Date: Tue, 24 Jan 2023 01:04:58 +0300 Message-Id: <20230123220500.21077-16-kirill.shutemov@linux.intel.com> X-Mailer: git-send-email 2.39.1 In-Reply-To: <20230123220500.21077-1-kirill.shutemov@linux.intel.com> References: <20230123220500.21077-1-kirill.shutemov@linux.intel.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Weihong Zhang LAM is enabled per-thread and gets inherited on fork(2)/clone(2). exec() reverts LAM status to the default disabled state. There are two test scenarios: - Fork test cases: These cases were used to test the inheritance of LAM for per-thread, Child process generated by fork() should inherit LAM feature from parent process, Child process can get the LAM mode same as parent process. - Execve test cases: Processes generated by execve() are different from processes generated by fork(), these processes revert LAM status to disabled status. Signed-off-by: Weihong Zhang Signed-off-by: Kirill A. Shutemov Acked-by: Peter Zijlstra (Intel) --- tools/testing/selftests/x86/lam.c | 125 +++++++++++++++++++++++++++++- 1 file changed, 121 insertions(+), 4 deletions(-) diff --git a/tools/testing/selftests/x86/lam.c b/tools/testing/selftests/x86/lam.c index 52750ebd0887..ebabd4333b7d 100644 --- a/tools/testing/selftests/x86/lam.c +++ b/tools/testing/selftests/x86/lam.c @@ -37,8 +37,9 @@ #define FUNC_MMAP 0x4 #define FUNC_SYSCALL 0x8 #define FUNC_URING 0x10 +#define FUNC_INHERITE 0x20 -#define TEST_MASK 0x1f +#define TEST_MASK 0x3f #define LOW_ADDR (0x1UL << 30) #define HIGH_ADDR (0x3UL << 48) @@ -174,6 +175,28 @@ static unsigned long get_default_tag_bits(void) return lam; } +/* + * Set tagged address and read back untag mask. + * check if the untag mask is expected. + */ +static int get_lam(void) +{ + uint64_t ptr = 0; + int ret = -1; + /* Get untagged mask */ + if (syscall(SYS_arch_prctl, ARCH_GET_UNTAG_MASK, &ptr) == -1) + return -1; + + /* Check mask returned is expected */ + if (ptr == ~(LAM_U57_MASK)) + ret = LAM_U57_BITS; + else if (ptr == -1ULL) + ret = LAM_NONE; + + + return ret; +} + /* According to LAM mode, set metadata in high bits */ static uint64_t set_metadata(uint64_t src, unsigned long lam) { @@ -581,7 +604,7 @@ int do_uring(unsigned long lam) switch (lam) { case LAM_U57_BITS: /* Clear bits 62:57 */ - addr = (addr & ~(0x3fULL << 57)); + addr = (addr & ~(LAM_U57_MASK)); break; } free((void *)addr); @@ -632,6 +655,72 @@ static int fork_test(struct testcases *test) return ret; } +static int handle_execve(struct testcases *test) +{ + int ret, child_ret; + int lam = test->lam; + pid_t pid; + + pid = fork(); + if (pid < 0) { + perror("Fork failed."); + ret = 1; + } else if (pid == 0) { + char path[PATH_MAX]; + + /* Set LAM mode in parent process */ + if (set_lam(lam) != 0) + return 1; + + /* Get current binary's path and the binary was run by execve */ + if (readlink("/proc/self/exe", path, PATH_MAX) <= 0) + exit(-1); + + /* run binary to get LAM mode and return to parent process */ + if (execlp(path, path, "-t 0x0", NULL) < 0) { + perror("error on exec"); + exit(-1); + } + } else { + wait(&child_ret); + ret = WEXITSTATUS(child_ret); + if (ret != LAM_NONE) + return 1; + } + + return 0; +} + +static int handle_inheritance(struct testcases *test) +{ + int ret, child_ret; + int lam = test->lam; + pid_t pid; + + /* Set LAM mode in parent process */ + if (set_lam(lam) != 0) + return 1; + + pid = fork(); + if (pid < 0) { + perror("Fork failed."); + return 1; + } else if (pid == 0) { + /* Set LAM mode in parent process */ + int child_lam = get_lam(); + + exit(child_lam); + } else { + wait(&child_ret); + ret = WEXITSTATUS(child_ret); + + if (lam != ret) + return 1; + } + + return 0; +} + static void run_test(struct testcases *test, int count) { int i, ret = 0; @@ -740,11 +829,26 @@ static struct testcases mmap_cases[] = { }, }; +static struct testcases inheritance_cases[] = { + { + .expected = 0, + .lam = LAM_U57_BITS, + .test_func = handle_inheritance, + .msg = "FORK: LAM_U57, child process should get LAM mode same as parent\n", + }, + { + .expected = 0, + .lam = LAM_U57_BITS, + .test_func = handle_execve, + .msg = "EXECVE: LAM_U57, child process should get disabled LAM mode\n", + }, +}; + static void cmd_help(void) { printf("usage: lam [-h] [-t test list]\n"); printf("\t-t test list: run tests specified in the test list, default:0x%x\n", TEST_MASK); - printf("\t\t0x1:malloc; 0x2:max_bits; 0x4:mmap; 0x8:syscall; 0x10:io_uring.\n"); + printf("\t\t0x1:malloc; 0x2:max_bits; 0x4:mmap; 0x8:syscall; 0x10:io_uring; 0x20:inherit;\n"); printf("\t-h: help\n"); } @@ -764,7 +868,7 @@ int main(int argc, char **argv) switch (c) { case 't': tests = strtoul(optarg, NULL, 16); - if (!(tests & TEST_MASK)) { + if (tests && !(tests & TEST_MASK)) { ksft_print_msg("Invalid argument!\n"); return -1; } @@ -778,6 +882,16 @@ int main(int argc, char **argv) } } + /* + * When tests is 0, it is not a real test case; + * the option used by test case(execve) to check the lam mode in + * process generated by execve, the process read back lam mode and + * check with lam mode in parent process. + */ + if (!tests) + return (get_lam()); + + /* Run test cases */ if (tests & FUNC_MALLOC) run_test(malloc_cases, ARRAY_SIZE(malloc_cases)); @@ -793,6 +907,9 @@ int main(int argc, char **argv) if (tests & FUNC_URING) run_test(uring_cases, ARRAY_SIZE(uring_cases)); + if (tests & FUNC_INHERITE) + run_test(inheritance_cases, ARRAY_SIZE(inheritance_cases)); + ksft_set_plan(tests_cnt); return ksft_exit_pass(); -- 2.39.1