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=-12.8 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable 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 C35E8C433E3 for ; Mon, 27 Jul 2020 09:15:07 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A04AE2075D for ; Mon, 27 Jul 2020 09:15:07 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=citrix.com header.i=@citrix.com header.b="IfxfXrJ/" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727896AbgG0JPG (ORCPT ); Mon, 27 Jul 2020 05:15:06 -0400 Received: from esa1.hc3370-68.iphmx.com ([216.71.145.142]:33530 "EHLO esa1.hc3370-68.iphmx.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726278AbgG0JPF (ORCPT ); Mon, 27 Jul 2020 05:15:05 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=citrix.com; s=securemail; t=1595841304; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=yXg+mOKMXOlPk9hYGg2gJuPP2ADAccszlFJ6TOt/+Ug=; b=IfxfXrJ/joTh9ku3J7FuyT0KyFAAzt4bHsRv/vFVYYBTRqQSPcbmj/IM v4cpmsGTUy+AKQexRzegb1s3RO+XY+BnQ4REx8EQwJsZKZiwvTtc6QgTX 4086FOVZ5PmNZxHJm4z4pidOJ84alp/+YAVPOAUPXKur+cJu/AUNYBt3k A=; Authentication-Results: esa1.hc3370-68.iphmx.com; dkim=none (message not signed) header.i=none IronPort-SDR: /lonDtJpry0GWq2IuiXzOVqYuyFYZER9q6g6pJnZVdsuhB60qYm8sw5ir81a6lE5JD3VvhAgnZ uuL5JM5gPHap68Oz7Fo4P5sHe+FH6rqD/766TtL7+nfxGgX5SQLd2SdX4TYFz/FTZ0ajYT3Xbt rB6divUhbolOgbljhK0WH+nMFJ5IRNvSU3I9OV+jZvZifd4q2AgNFuE8TTh/foBPfTGMsl9Jqf 0SJi+bG8Sd9zz8aeie0dIrsLOFQmPTiT1b5E8G3k8quqYAfiezZ6DqObqRbQGcB2zt1RJBuw1b Acc= X-SBRS: 2.7 X-MesageID: 23569857 X-Ironport-Server: esa1.hc3370-68.iphmx.com X-Remote-IP: 162.221.158.21 X-Policy: $RELAYED X-IronPort-AV: E=Sophos;i="5.75,402,1589256000"; d="scan'208";a="23569857" From: Roger Pau Monne To: CC: Roger Pau Monne , Juergen Gross , , Boris Ostrovsky , Stefano Stabellini , Subject: [PATCH v3 1/4] xen/balloon: fix accounting in alloc_xenballooned_pages error path Date: Mon, 27 Jul 2020 11:13:39 +0200 Message-ID: <20200727091342.52325-2-roger.pau@citrix.com> X-Mailer: git-send-email 2.27.0 In-Reply-To: <20200727091342.52325-1-roger.pau@citrix.com> References: <20200727091342.52325-1-roger.pau@citrix.com> MIME-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org target_unpopulated is incremented with nr_pages at the start of the function, but the call to free_xenballooned_pages will only subtract pgno number of pages, and thus the rest need to be subtracted before returning or else accounting will be skewed. Signed-off-by: Roger Pau Monné Reviewed-by: Juergen Gross Cc: stable@vger.kernel.org --- Cc: Boris Ostrovsky Cc: Juergen Gross Cc: Stefano Stabellini Cc: xen-devel@lists.xenproject.org --- drivers/xen/balloon.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/drivers/xen/balloon.c b/drivers/xen/balloon.c index 77c57568e5d7..3cb10ed32557 100644 --- a/drivers/xen/balloon.c +++ b/drivers/xen/balloon.c @@ -630,6 +630,12 @@ int alloc_xenballooned_pages(int nr_pages, struct page **pages) out_undo: mutex_unlock(&balloon_mutex); free_xenballooned_pages(pgno, pages); + /* + * NB: free_xenballooned_pages will only subtract pgno pages, but since + * target_unpopulated is incremented with nr_pages at the start we need + * to remove the remaining ones also, or accounting will be screwed. + */ + balloon_stats.target_unpopulated -= nr_pages - pgno; return ret; } EXPORT_SYMBOL(alloc_xenballooned_pages); -- 2.27.0