From patchwork Mon Jul 27 09:13:39 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Roger Pau Monne X-Patchwork-Id: 11686643 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 E5C63138C for ; Mon, 27 Jul 2020 09:16:02 +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 C18812064B for ; Mon, 27 Jul 2020 09:16:02 +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/" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org C18812064B Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=citrix.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=xen-devel-bounces@lists.xenproject.org Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1jzzDx-0004OX-Se; Mon, 27 Jul 2020 09:15:09 +0000 Received: from us1-rack-iad1.inumbo.com ([172.99.69.81]) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1jzzDx-0004OD-H3 for xen-devel@lists.xenproject.org; Mon, 27 Jul 2020 09:15:09 +0000 X-Inumbo-ID: a8040e54-cfe9-11ea-8a7e-bc764e2007e4 Received: from esa1.hc3370-68.iphmx.com (unknown [216.71.145.142]) by us1-rack-iad1.inumbo.com (Halon) with ESMTPS id a8040e54-cfe9-11ea-8a7e-bc764e2007e4; Mon, 27 Jul 2020 09:15:04 +0000 (UTC) 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: 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 X-BeenThere: xen-devel@lists.xenproject.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Cc: Juergen Gross , Stefano Stabellini , stable@vger.kernel.org, xen-devel@lists.xenproject.org, Boris Ostrovsky , Roger Pau Monne Errors-To: xen-devel-bounces@lists.xenproject.org Sender: "Xen-devel" 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);