From patchwork Wed Apr 12 17:43:48 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sumit Semwal X-Patchwork-Id: 97339 Delivered-To: patch@linaro.org Received: by 10.140.109.52 with SMTP id k49csp374592qgf; Wed, 12 Apr 2017 10:45:13 -0700 (PDT) X-Received: by 10.84.214.16 with SMTP id h16mr20066458pli.96.1492019113799; Wed, 12 Apr 2017 10:45:13 -0700 (PDT) Return-Path: Received: from vger.kernel.org (vger.kernel.org. [209.132.180.67]) by mx.google.com with ESMTP id z21si18652409pgh.397.2017.04.12.10.45.13; Wed, 12 Apr 2017 10:45:13 -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 S1755399AbdDLRo4 (ORCPT + 6 others); Wed, 12 Apr 2017 13:44:56 -0400 Received: from mail-pf0-f178.google.com ([209.85.192.178]:34181 "EHLO mail-pf0-f178.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753066AbdDLRox (ORCPT ); Wed, 12 Apr 2017 13:44:53 -0400 Received: by mail-pf0-f178.google.com with SMTP id c198so16983041pfc.1 for ; Wed, 12 Apr 2017 10:44:48 -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=JXsyRIAyYn/UEdhNisqhvq2j7/uVWo9KzhDwPs/6DwlJq0lpFCHQvYpkWd8YHsslcU ywy2ljVNC7yMjIc/d9VEaKoQ0qzLdes3P3vatlOd+G0hmR9WUAILd62OxCeuEEDMvhE0 oF3ia3yqXBtOVNh/MziOWNZmfVgLN/mDM7wOU= 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=NpX+/XEZJJFxO9bvgKzEqXkgQbXGdRHfR8t8HLQxuXB6qZ1kSd767kbG9aX4jD+9TE iHSV/m/m3nhwE5FViqdSQl6KiECWAy0a1jn0Z7PshDScl/PjL2hvULthOyPEdE1Zt6SJ uNc3gMsiLUL9dGErDwihH/CYaRun7OYyYKqT/wOdlKgZOv+zuqrlz4pepJ7FjnW/4o+m 14e3zulHm9lERa+O4gvizXvvdaHTTDCF5NXB5PVbS3ZHprVJl75+pHreG/KrVzJ9h4tE skm/cluwpgWTskbHJnSlVks+1qgcz/rhWwSiYlMK53uPFUlYdPRoms0hXafKF20O5QHm drUQ== X-Gm-Message-State: AFeK/H3WdQqnwhTnJQbjwgx8+pzSKGNzsz2G9XdrOv19qYytHaBc4bDXIF2dYtEnJOxuOcTb X-Received: by 10.84.197.1 with SMTP id m1mr84314715pld.183.1492019082666; Wed, 12 Apr 2017 10:44:42 -0700 (PDT) Received: from phantom.lan ([106.51.225.38]) by smtp.gmail.com with ESMTPSA id r17sm37750019pfa.13.2017.04.12.10.44.39 (version=TLS1_2 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Wed, 12 Apr 2017 10:44:41 -0700 (PDT) From: Sumit Semwal To: stable@vger.kernel.org Cc: Vitaly Kuznetsov , "K . Y . Srinivasan" , Greg Kroah-Hartman , Sumit Semwal Subject: [v2 PATCH for-4.4 14/16] hv: don't reset hv_context.tsc_page on crash Date: Wed, 12 Apr 2017 23:13:48 +0530 Message-Id: <1492019030-13567-15-git-send-email-sumit.semwal@linaro.org> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1492019030-13567-1-git-send-email-sumit.semwal@linaro.org> References: <1492019030-13567-1-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 }