From patchwork Fri Oct 11 00:40:55 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sean Christopherson X-Patchwork-Id: 11184745 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 4A11917EE for ; Fri, 11 Oct 2019 00:41:05 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 2B8B62190F for ; Fri, 11 Oct 2019 00:41:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727528AbfJKAlE (ORCPT ); Thu, 10 Oct 2019 20:41:04 -0400 Received: from mga18.intel.com ([134.134.136.126]:44342 "EHLO mga18.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728094AbfJKAlD (ORCPT ); Thu, 10 Oct 2019 20:41:03 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga006.jf.intel.com ([10.7.209.51]) by orsmga106.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 10 Oct 2019 17:41:01 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.67,282,1566889200"; d="scan'208";a="198542990" Received: from sjchrist-coffee.jf.intel.com ([10.54.74.41]) by orsmga006.jf.intel.com with ESMTP; 10 Oct 2019 17:41:01 -0700 From: Sean Christopherson To: Jarkko Sakkinen Cc: linux-sgx@vger.kernel.org Subject: [PATCH for_v23 1/5] x86/vdso: sgx: Fix misaligned stack bug when invoking exit handler Date: Thu, 10 Oct 2019 17:40:55 -0700 Message-Id: <20191011004059.28581-2-sean.j.christopherson@intel.com> X-Mailer: git-send-email 2.22.0 In-Reply-To: <20191011004059.28581-1-sean.j.christopherson@intel.com> References: <20191011004059.28581-1-sean.j.christopherson@intel.com> MIME-Version: 1.0 Sender: linux-sgx-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-sgx@vger.kernel.org Fix a recently introduced bug where an odd number of 8-byte parameters are pushed on the stack prior to invoking the userspace callback, which causes the CALL to execute with an unaligned stack and violate the x86_64 ABI. Reported-by: Cedric Xing Signed-off-by: Sean Christopherson --- arch/x86/entry/vdso/vsgx_enter_enclave.S | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/arch/x86/entry/vdso/vsgx_enter_enclave.S b/arch/x86/entry/vdso/vsgx_enter_enclave.S index fc5622dcd2fa..b63091818df1 100644 --- a/arch/x86/entry/vdso/vsgx_enter_enclave.S +++ b/arch/x86/entry/vdso/vsgx_enter_enclave.S @@ -135,10 +135,12 @@ ENTRY(__vdso_sgx_enter_enclave) .Linvoke_userspace_handler: /* * Align stack per x86_64 ABI. Save the original %rsp in %rbx to be - * restored after the callback returns. + * restored after the callback returns. Note, %rsp needs to be 16-byte + * aligned _after_ pushing the three parameters on the stack. */ mov %rsp, %rbx and $-0x10, %rsp + sub $0x8, %rsp /* Push @e, u_rsp and @tcs as parameters to the callback. */ push 0x18(%rbp)