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 X-Spam-Level: X-Spam-Status: No, score=-18.7 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id F022BC433E0 for ; Tue, 23 Feb 2021 11:12:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8BB4A64E32 for ; Tue, 23 Feb 2021 11:12:18 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232302AbhBWLMR (ORCPT ); Tue, 23 Feb 2021 06:12:17 -0500 Received: from mail.skyhub.de ([5.9.137.197]:47072 "EHLO mail.skyhub.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231701AbhBWLMP (ORCPT ); Tue, 23 Feb 2021 06:12:15 -0500 Received: from zn.tnic (p200300ec2f08d800f4a123a8a64e4d27.dip0.t-ipconnect.de [IPv6:2003:ec:2f08:d800:f4a1:23a8:a64e:4d27]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.skyhub.de (SuperMail on ZX Spectrum 128k) with ESMTPSA id 400761EC01CE; Tue, 23 Feb 2021 12:11:34 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=alien8.de; s=dkim; t=1614078694; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type: content-transfer-encoding:content-transfer-encoding:in-reply-to: references; bh=PRRcv0X1Lc/+5F9ee4mDYr4SyzrtXxI6gDWofpgstZI=; b=Fs0quUH8ycBXWNVNLda6wXP4Gui/qo7jH1fLn4BFr8wtBx/Xn+KSP/frjSSgOhrp3FSkEM RbtaNeokIx5CPwE+fkdBi9PQRFBmUztCKUKyhoJEvS8yRGrtGvqByQVPcsw4GjUhcfrQdr jlePjg0HYpYQegBI9soY9QR1VFSoFT8= From: Borislav Petkov To: Joerg Roedel Cc: X86 ML , LKML Subject: [PATCH] x86/sev-es: Remove subtraction of res variable Date: Tue, 23 Feb 2021 12:11:30 +0100 Message-Id: <20210223111130.16201-1-bp@alien8.de> X-Mailer: git-send-email 2.29.2 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Borislav Petkov vc_decode_insn() calls copy_from_kernel_nofault() by way of vc_fetch_insn_kernel() to fetch 15 bytes max of opcodes to decode. copy_from_kernel_nofault() returns negative on error and 0 on success. The error case is handled by returning ES_EXCEPTION. In the success case, the ret variable which contains the return value is 0 so there's no need to subtract it from MAX_INSN_SIZE when initializing the insn buffer for further decoding. Remove it. No functional changes. Signed-off-by: Borislav Petkov --- arch/x86/kernel/sev-es.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/x86/kernel/sev-es.c b/arch/x86/kernel/sev-es.c index 84c1821819af..1e78f4bd7bf2 100644 --- a/arch/x86/kernel/sev-es.c +++ b/arch/x86/kernel/sev-es.c @@ -267,7 +267,7 @@ static enum es_result vc_decode_insn(struct es_em_ctxt *ctxt) return ES_EXCEPTION; } - insn_init(&ctxt->insn, buffer, MAX_INSN_SIZE - res, 1); + insn_init(&ctxt->insn, buffer, MAX_INSN_SIZE, 1); insn_get_length(&ctxt->insn); } -- 2.29.2