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 45570C05027 for ; Mon, 20 Feb 2023 03:10:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229904AbjBTDKq (ORCPT ); Sun, 19 Feb 2023 22:10:46 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57166 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229593AbjBTDKn (ORCPT ); Sun, 19 Feb 2023 22:10:43 -0500 Received: from gnuweeb.org (gnuweeb.org [51.81.211.47]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D61CBE075; Sun, 19 Feb 2023 19:10:34 -0800 (PST) Received: from localhost.localdomain (unknown [182.253.183.169]) by gnuweeb.org (Postfix) with ESMTPSA id 35EB88314A; Mon, 20 Feb 2023 03:10:27 +0000 (UTC) X-GW-Data: lPqxHiMPbJw1wb7CM9QUryAGzr0yq5atzVDdxTR0iA== DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=gnuweeb.org; s=default; t=1676862634; bh=8+ewo69UeU0rHb78uAAPEiHOOweqFJBmdi5nkVAJieo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=PE01Ct8AR9GQuFjnvOQzf1W28HATJ6XpOq9xa0FIejWgb0rH9phaTu57ipNwhsMrw VsrIE2JWbD3UV8FNf9wHRv9pY+gHCnXBPjQlcKj/E8wWrYbnkqqhiaBtw1cl3IIAKm CnVIGdPKMeBBM+zxTzwpzxrpik4bvCTTM8IRwX7ycw8MdIAfhw2DnUA/WS1DQr3cRJ Txx8d6po9XSiNJ34BRbKMpvh/SOoVlVylAt/uJpB8yCfY9P4uBUHd0iyVkgVGxy+gJ 1chxDMEkOGF6auqWrl/7msqsj8n++Hrcjc3pL983UEJqnNq/gdgAauPIT24CaUOT6l /2cPDCBbfPCgw== From: Ammar Faizi To: Ingo Molnar , "H. Peter Anvin" , Dave Hansen , Xin Li Cc: Ammar Faizi , Andrew Cooper , Andy Lutomirski , Borislav Petkov , Thomas Gleixner , Dave Hansen , Peter Zijlstra , "Kirill A. Shutemov" , x86 Mailing List , Linux Kernel Mailing List , Linux Kselftest Mailing List , GNU/Weeb Mailing List Subject: [RESEND RFC PATCH v8 3/3] selftests/x86: sysret_rip: Test SYSRET with a signal handler Date: Mon, 20 Feb 2023 10:09:59 +0700 Message-Id: <20230220030959.119222-4-ammarfaizi2@gnuweeb.org> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20230220030959.119222-1-ammarfaizi2@gnuweeb.org> References: <20230220030959.119222-1-ammarfaizi2@gnuweeb.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The current test_sigreturn_to() goes to the slow-path syscall with IRET due to non-canonical addresses. It uses the SIGUSR1 signal to perform the test. Add a similar test that goes to the SYSRET path instead of IRET using the SIGUSR2 signal. There are two cases: A) 'syscall' in a FRED system preserves %rcx and %r11. B) 'syscall' in a non-FRED system sets %rcx=%rip and %r11=%rflags. The __raise(SIGUSR2) call verifies the 'syscall' behavior consistency when dealing with a signal handler. It must always be (A) or always be (B). Not a mix of them. Cc: Xin Li Link: https://lore.kernel.org/lkml/8770815f-0f23-d0c5-e56a-d401827842c9@zytor.com Suggested-by: H. Peter Anvin (Intel) Signed-off-by: Ammar Faizi --- tools/testing/selftests/x86/sysret_rip.c | 30 ++++++++++++++++++++++++ 1 file changed, 30 insertions(+) diff --git a/tools/testing/selftests/x86/sysret_rip.c b/tools/testing/selftests/x86/sysret_rip.c index 1531593b50d02150..746801675fe77e9c 100644 --- a/tools/testing/selftests/x86/sysret_rip.c +++ b/tools/testing/selftests/x86/sysret_rip.c @@ -274,6 +274,28 @@ static void test_syscall_rcx_r11_consistent(void) do_syscall(__NR_getppid, 0, 0, 0, 0, 0, 0); } +static unsigned long usr2_rcx; +static unsigned long usr2_r11; + +static void sigusr2(int sig, siginfo_t *info, void *ctx_void) +{ + ucontext_t *ctx = (ucontext_t*)ctx_void; + + usr2_r11 = ctx->uc_mcontext.gregs[REG_R11]; + usr2_rcx = ctx->uc_mcontext.gregs[REG_RCX]; + + check_regs_result(ctx->uc_mcontext.gregs[REG_R11], + ctx->uc_mcontext.gregs[REG_RCX], + ctx->uc_mcontext.gregs[REG_RBX]); +} + +static void test_sysret_consistent(void) +{ + printf("[RUN]\ttest_sysret_consistent\n"); + __raise(SIGUSR2); + printf("[OK]\tRCX = %#lx; R11 = %#lx\n", usr2_rcx, usr2_r11); +} + int main() { int i; @@ -291,6 +313,14 @@ int main() for (i = 47; i < 64; i++) test_sigreturn_to(1UL<