From mboxrd@z Thu Jan 1 00:00:00 1970 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 950AEC761AF for ; Tue, 28 Mar 2023 14:53:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233038AbjC1Oxd (ORCPT ); Tue, 28 Mar 2023 10:53:33 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52608 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233270AbjC1OxW (ORCPT ); Tue, 28 Mar 2023 10:53:22 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B637D19C for ; Tue, 28 Mar 2023 07:53:21 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 2C00D6181B for ; Tue, 28 Mar 2023 14:53:21 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 2CF7CC433EF; Tue, 28 Mar 2023 14:53:20 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1680015200; bh=Rws4IoTyzMXKlSKdC9oln+/HmUZ+0VC8t40sNPeVbIc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Gb6xxPGGIpCViXqD26Aht1vhR5xcX2282R5GksIPJWnJeNxAxWwbBkUU+WWJgB/AS BEXWU6pgQ2NP78PPlGBGBo84b+rfZyVoVGAyP9EXU0/9l+hwVk7tp6rQGgQXLTUW+X 9hU/Qr55ObS8wUCVT7pxVfTSZzBHxRAFmXLMQGsM= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, "Chang S. Bae" , Dave Hansen Subject: [PATCH 6.2 171/240] selftests/x86/amx: Add a ptrace test Date: Tue, 28 Mar 2023 16:42:14 +0200 Message-Id: <20230328142626.776861250@linuxfoundation.org> X-Mailer: git-send-email 2.40.0 In-Reply-To: <20230328142619.643313678@linuxfoundation.org> References: <20230328142619.643313678@linuxfoundation.org> User-Agent: quilt/0.67 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Chang S. Bae commit 62faca1ca10cc84e99ae7f38aa28df2bc945369b upstream. Include a test case to validate the XTILEDATA injection to the target. Also, it ensures the kernel's ability to copy states between different XSAVE formats. Refactor the memcmp() code to be usable for the state validation. Signed-off-by: Chang S. Bae Signed-off-by: Dave Hansen Cc: stable@vger.kernel.org Link: https://lore.kernel.org/all/20230227210504.18520-3-chang.seok.bae%40intel.com Signed-off-by: Greg Kroah-Hartman --- tools/testing/selftests/x86/amx.c | 108 ++++++++++++++++++++++++++++++++++++-- 1 file changed, 105 insertions(+), 3 deletions(-) --- a/tools/testing/selftests/x86/amx.c +++ b/tools/testing/selftests/x86/amx.c @@ -14,8 +14,10 @@ #include #include #include +#include #include #include +#include #include "../kselftest.h" /* For __cpuid_count() */ @@ -583,6 +585,13 @@ static void test_dynamic_state(void) _exit(0); } +static inline int __compare_tiledata_state(struct xsave_buffer *xbuf1, struct xsave_buffer *xbuf2) +{ + return memcmp(&xbuf1->bytes[xtiledata.xbuf_offset], + &xbuf2->bytes[xtiledata.xbuf_offset], + xtiledata.size); +} + /* * Save current register state and compare it to @xbuf1.' * @@ -599,9 +608,7 @@ static inline bool __validate_tiledata_r fatal_error("failed to allocate XSAVE buffer\n"); xsave(xbuf2, XFEATURE_MASK_XTILEDATA); - ret = memcmp(&xbuf1->bytes[xtiledata.xbuf_offset], - &xbuf2->bytes[xtiledata.xbuf_offset], - xtiledata.size); + ret = __compare_tiledata_state(xbuf1, xbuf2); free(xbuf2); @@ -826,6 +833,99 @@ static void test_context_switch(void) free(finfo); } +/* Ptrace test */ + +/* + * Make sure the ptracee has the expanded kernel buffer on the first + * use. Then, initialize the state before performing the state + * injection from the ptracer. + */ +static inline void ptracee_firstuse_tiledata(void) +{ + load_rand_tiledata(stashed_xsave); + init_xtiledata(); +} + +/* + * Ptracer injects the randomized tile data state. It also reads + * before and after that, which will execute the kernel's state copy + * functions. So, the tester is advised to double-check any emitted + * kernel messages. + */ +static void ptracer_inject_tiledata(pid_t target) +{ + struct xsave_buffer *xbuf; + struct iovec iov; + + xbuf = alloc_xbuf(); + if (!xbuf) + fatal_error("unable to allocate XSAVE buffer"); + + printf("\tRead the init'ed tiledata via ptrace().\n"); + + iov.iov_base = xbuf; + iov.iov_len = xbuf_size; + + memset(stashed_xsave, 0, xbuf_size); + + if (ptrace(PTRACE_GETREGSET, target, (uint32_t)NT_X86_XSTATE, &iov)) + fatal_error("PTRACE_GETREGSET"); + + if (!__compare_tiledata_state(stashed_xsave, xbuf)) + printf("[OK]\tThe init'ed tiledata was read from ptracee.\n"); + else + printf("[FAIL]\tThe init'ed tiledata was not read from ptracee.\n"); + + printf("\tInject tiledata via ptrace().\n"); + + load_rand_tiledata(xbuf); + + memcpy(&stashed_xsave->bytes[xtiledata.xbuf_offset], + &xbuf->bytes[xtiledata.xbuf_offset], + xtiledata.size); + + if (ptrace(PTRACE_SETREGSET, target, (uint32_t)NT_X86_XSTATE, &iov)) + fatal_error("PTRACE_SETREGSET"); + + if (ptrace(PTRACE_GETREGSET, target, (uint32_t)NT_X86_XSTATE, &iov)) + fatal_error("PTRACE_GETREGSET"); + + if (!__compare_tiledata_state(stashed_xsave, xbuf)) + printf("[OK]\tTiledata was correctly written to ptracee.\n"); + else + printf("[FAIL]\tTiledata was not correctly written to ptracee.\n"); +} + +static void test_ptrace(void) +{ + pid_t child; + int status; + + child = fork(); + if (child < 0) { + err(1, "fork"); + } else if (!child) { + if (ptrace(PTRACE_TRACEME, 0, NULL, NULL)) + err(1, "PTRACE_TRACEME"); + + ptracee_firstuse_tiledata(); + + raise(SIGTRAP); + _exit(0); + } + + do { + wait(&status); + } while (WSTOPSIG(status) != SIGTRAP); + + ptracer_inject_tiledata(child); + + ptrace(PTRACE_DETACH, child, NULL, NULL); + wait(&status); + if (!WIFEXITED(status) || WEXITSTATUS(status)) + err(1, "ptrace test"); +} + int main(void) { /* Check hardware availability at first */ @@ -846,6 +946,8 @@ int main(void) ctxtswtest_config.num_threads = 5; test_context_switch(); + test_ptrace(); + clearhandler(SIGILL); free_stashed_xsave();