From patchwork Fri Oct 23 08:39:04 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jan Beulich X-Patchwork-Id: 11852543 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 AEB451744 for ; Fri, 23 Oct 2020 08:39:44 +0000 (UTC) Received: from lists.xenproject.org (lists.xenproject.org [192.237.175.120]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 6EF1421527 for ; Fri, 23 Oct 2020 08:39:44 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=suse.com header.i=@suse.com header.b="t7vu6KTa" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 6EF1421527 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=suse.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=xen-devel-bounces@lists.xenproject.org Received: from list by lists.xenproject.org with outflank-mailman.10785.28784 (Exim 4.92) (envelope-from ) id 1kVsbI-0006o5-TL; Fri, 23 Oct 2020 08:39:04 +0000 X-Outflank-Mailman: Message body and most headers restored to incoming version Received: by outflank-mailman (output) from mailman id 10785.28784; Fri, 23 Oct 2020 08:39:04 +0000 X-BeenThere: xen-devel@lists.xenproject.org List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Errors-To: xen-devel-bounces@lists.xenproject.org Precedence: list Sender: "Xen-devel" Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1kVsbI-0006ny-QO; Fri, 23 Oct 2020 08:39:04 +0000 Received: by outflank-mailman (input) for mailman id 10785; Fri, 23 Oct 2020 08:39:03 +0000 Received: from us1-rack-iad1.inumbo.com ([172.99.69.81]) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1kVsbH-0006no-Go for xen-devel@lists.xenproject.org; Fri, 23 Oct 2020 08:39:03 +0000 Received: from mx2.suse.de (unknown [195.135.220.15]) by us1-rack-iad1.inumbo.com (Halon) with ESMTPS id 37783b02-83e7-45ee-8acf-b93102008a45; Fri, 23 Oct 2020 08:39:02 +0000 (UTC) Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id 1ADBBABF4; Fri, 23 Oct 2020 08:39:02 +0000 (UTC) Received: from us1-rack-iad1.inumbo.com ([172.99.69.81]) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1kVsbH-0006no-Go for xen-devel@lists.xenproject.org; Fri, 23 Oct 2020 08:39:03 +0000 X-Inumbo-ID: 37783b02-83e7-45ee-8acf-b93102008a45 Received: from mx2.suse.de (unknown [195.135.220.15]) by us1-rack-iad1.inumbo.com (Halon) with ESMTPS id 37783b02-83e7-45ee-8acf-b93102008a45; Fri, 23 Oct 2020 08:39:02 +0000 (UTC) X-Virus-Scanned: by amavisd-new at test-mx.suse.de DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=susede1; t=1603442342; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=M/CSsTj+azQBJhNlEDi7dDTrUxCNiHutJMIEl+th0O8=; b=t7vu6KTaiVJ6LAEIUaAxtoG8+NhI8Z8DpVtQ5GaRcQT7OaulrKF+4IKkvmuTJxQfjPw+j4 kMJcvCLPepqJr/VsbKU0Yc9/cAwiqrkeWO1OnHOz8snflj7F6sO2dIlDAvwZWwh6oY7xz1 nBtGBZ2uGOcV/R9ab/CRWbfROzGIU3A= Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id 1ADBBABF4; Fri, 23 Oct 2020 08:39:02 +0000 (UTC) Subject: [PATCH v3 7/7] x86: make guarding against straight-line speculation optional From: Jan Beulich To: "xen-devel@lists.xenproject.org" Cc: Andrew Cooper , Wei Liu , =?utf-8?q?Roger_Pau_Monn=C3=A9?= References: <7065e2dc-f846-be79-1081-682c2295358c@suse.com> Message-ID: <06067023-0f61-3e37-a0a4-4254df1f5c16@suse.com> Date: Fri, 23 Oct 2020 10:39:04 +0200 User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:68.0) Gecko/20100101 Thunderbird/68.12.1 MIME-Version: 1.0 In-Reply-To: <7065e2dc-f846-be79-1081-682c2295358c@suse.com> Content-Language: en-US Put insertion of INT3 behind CONFIG_SPECULATIVE_HARDEN_BRANCH conditionals. Signed-off-by: Jan Beulich --- v3: New. --- a/xen/arch/x86/indirect-thunk.S +++ b/xen/arch/x86/indirect-thunk.S @@ -11,8 +11,10 @@ #include +#ifdef CONFIG_SPECULATIVE_HARDEN_BRANCH /* Don't transform the "ret" further down. */ .purgem ret +#endif .macro IND_THUNK_RETPOLINE reg:req call 2f @@ -45,7 +47,9 @@ ENTRY(__x86_indirect_thunk_\reg) __stringify(IND_THUNK_LFENCE \reg), X86_FEATURE_IND_THUNK_LFENCE, \ __stringify(IND_THUNK_JMP \reg), X86_FEATURE_IND_THUNK_JMP +#ifdef CONFIG_SPECULATIVE_HARDEN_BRANCH int3 /* Halt straight-line speculation */ +#endif .size __x86_indirect_thunk_\reg, . - __x86_indirect_thunk_\reg .type __x86_indirect_thunk_\reg, @function --- a/xen/include/asm-x86/asm-defns.h +++ b/xen/include/asm-x86/asm-defns.h @@ -51,6 +51,8 @@ INDIRECT_BRANCH jmp \arg .endm +#ifdef CONFIG_SPECULATIVE_HARDEN_BRANCH + /* * To guard against speculation past RET, insert a breakpoint insn * immediately after them. @@ -66,3 +68,5 @@ .word \operand .endif .endm + +#endif