From patchwork Thu Apr 20 07:38:43 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sumit Semwal X-Patchwork-Id: 97718 Delivered-To: patch@linaro.org Received: by 10.140.109.52 with SMTP id k49csp667489qgf; Thu, 20 Apr 2017 00:39:23 -0700 (PDT) X-Received: by 10.98.159.144 with SMTP id v16mr6636089pfk.57.1492673963819; Thu, 20 Apr 2017 00:39:23 -0700 (PDT) Return-Path: Received: from vger.kernel.org (vger.kernel.org. [209.132.180.67]) by mx.google.com with ESMTP id 203si1845905pgf.183.2017.04.20.00.39.23; Thu, 20 Apr 2017 00:39:23 -0700 (PDT) Received-SPF: pass (google.com: best guess record for domain of stable-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; dkim=pass header.i=@linaro.org; spf=pass (google.com: best guess record for domain of stable-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=stable-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=linaro.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S943086AbdDTHjP (ORCPT + 6 others); Thu, 20 Apr 2017 03:39:15 -0400 Received: from mail-yb0-f181.google.com ([209.85.213.181]:34617 "EHLO mail-yb0-f181.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S943104AbdDTHjO (ORCPT ); Thu, 20 Apr 2017 03:39:14 -0400 Received: by mail-yb0-f181.google.com with SMTP id 11so17678925ybw.1 for ; Thu, 20 Apr 2017 00:39:13 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=b/4EdhaVvM16veNbBlzw6pKOeSID24uDb6DOWoRvntM=; b=RHxj8GKjb/puXrOnTots6qXJynpoA7yNT2RwOlfjSJ3mNGvoIK+m7W7rlk1Cpzam0V UMhV6cg8fAg5KpwNObFjLkvrwQ+lUh3+q7HJgMnZwV2OFOHHXjPA/bcxRuF+GrTe2j+3 DKzaD9H/FqhlbuzyhYupMcTQFRDFKeYjm1M7w= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=b/4EdhaVvM16veNbBlzw6pKOeSID24uDb6DOWoRvntM=; b=P3WL6X6y6GBCklfXOrN7nh1ZOmd0FMyMVTJdgiQie5ZlRQDrsqsKh1UzAMqfBS21CK cQtK6VA7inGTbdGW0ARNP7kA5aEjTIQO8rJ14FvCAdA39EEg3YrpMoCnUG3nolrSs2Kn VaTJjeDUPW/bLROmbsYwAY11av8c87BkYgXvWly3lznNyOJGpuf9a6K/f9+sjjYfX8T0 wKIjWAwT3hMtyaIxeG4nx2T5bZ5mNyqiyCzvztnpCzpSqTnVnIIviki1JpYeO/EimATs GOBidE1PsEUj3ceGZEY7c8W6zN1AXwSxAAlYHgxE/aCDcamCi4OTyoln5WNfGswE7tow 4MVw== X-Gm-Message-State: AN3rC/4IMML6OCOA6XWtacQWlaWnUj858Pv82mwhP/u/GIGHWZooFyqf kuYhQDkK3rHyaQ8C X-Received: by 10.98.220.201 with SMTP id c70mr6778574pfl.77.1492673953158; Thu, 20 Apr 2017 00:39:13 -0700 (PDT) Received: from phantom.lan ([106.51.225.38]) by smtp.gmail.com with ESMTPSA id t2sm8497717pfl.34.2017.04.20.00.39.10 (version=TLS1_2 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Thu, 20 Apr 2017 00:39:12 -0700 (PDT) From: Sumit Semwal To: stable@vger.kernel.org Cc: Vitaly Kuznetsov , "K . Y . Srinivasan" , Greg Kroah-Hartman , Sumit Semwal Subject: [v3 PATCH for-4.4 7/7] hv: don't reset hv_context.tsc_page on crash Date: Thu, 20 Apr 2017 13:08:43 +0530 Message-Id: <1492673923-1352-8-git-send-email-sumit.semwal@linaro.org> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1492673923-1352-1-git-send-email-sumit.semwal@linaro.org> References: <1492673923-1352-1-git-send-email-sumit.semwal@linaro.org> Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Vitaly Kuznetsov [ Upstream commit 56ef6718a1d8d77745033c5291e025ce18504159 ] It may happen that secondary CPUs are still alive and resetting hv_context.tsc_page will cause a consequent crash in read_hv_clock_tsc() as we don't check for it being not NULL there. It is safe as we're not freeing this page anyways. Signed-off-by: Vitaly Kuznetsov Signed-off-by: K. Y. Srinivasan Cc: Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sumit Semwal --- drivers/hv/hv.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) -- 2.7.4 diff --git a/drivers/hv/hv.c b/drivers/hv/hv.c index ddbf7e7..8ce1f2e 100644 --- a/drivers/hv/hv.c +++ b/drivers/hv/hv.c @@ -305,9 +305,10 @@ void hv_cleanup(bool crash) hypercall_msr.as_uint64 = 0; wrmsrl(HV_X64_MSR_REFERENCE_TSC, hypercall_msr.as_uint64); - if (!crash) + if (!crash) { vfree(hv_context.tsc_page); - hv_context.tsc_page = NULL; + hv_context.tsc_page = NULL; + } } #endif }