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,URIBL_BLOCKED,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 F28F6C433E5 for ; Fri, 24 Jul 2020 12:42:54 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C82F02074B for ; Fri, 24 Jul 2020 12:42:54 +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="deiS7u4X" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726997AbgGXMmy (ORCPT ); Fri, 24 Jul 2020 08:42:54 -0400 Received: from esa4.hc3370-68.iphmx.com ([216.71.155.144]:26861 "EHLO esa4.hc3370-68.iphmx.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726329AbgGXMmx (ORCPT ); Fri, 24 Jul 2020 08:42:53 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=citrix.com; s=securemail; t=1595594572; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=aDtTphrzz9VOwTJvjWtl31/5xlDEnj/EJHimWB6gA4o=; b=deiS7u4XhPpWcyrTBguRa/HFybY2oT+527j9v9hDZYTj5QajGP0eDFIf e1sQ+lNHIXbFlx2ROI87387Q4aePbqj0QV1UOdE2rXSEJC29D3E+/qB+1 GGH+UiStNhEGpK7mKKCNQCvRSRrUc6kDbgbeYrtTshSp8kPd6IczNqZH0 U=; Authentication-Results: esa4.hc3370-68.iphmx.com; dkim=none (message not signed) header.i=none IronPort-SDR: KJCsrxedNsP6PXR2GRxBdY4JBtMMaZKb/2iWqx70jsyhvQVs2mJ4a6ODJl6e5Ze0n71njR8l7V 9U+neT0HVYP3POae1Ostbc3PyXtJbBN2r4zxUF0cQs6LBnJFr0VNVu/tNCJc9T1E4naoIb331o PnI7RkHi0XdVA2g0geZOyiF6+NKoWClGj8G1fo1E2jxpTrVvVikRzuiGwbtXCIN56qO7yeEIjv kh6FrSOIHklNuDPUeb45cpzlQ/2JrbYLIt+iJwQswgcnxS7Z13OFRECZhFNlp6l07ZlfxwhxDd Xyk= X-SBRS: 2.7 X-MesageID: 23987140 X-Ironport-Server: esa4.hc3370-68.iphmx.com X-Remote-IP: 162.221.158.21 X-Policy: $RELAYED X-IronPort-AV: E=Sophos;i="5.75,390,1589256000"; d="scan'208";a="23987140" From: Roger Pau Monne To: CC: Roger Pau Monne , , "Boris Ostrovsky" , Juergen Gross , Stefano Stabellini , Subject: [PATCH v2 1/4] xen/balloon: fix accounting in alloc_xenballooned_pages error path Date: Fri, 24 Jul 2020 14:42:38 +0200 Message-ID: <20200724124241.48208-2-roger.pau@citrix.com> X-Mailer: git-send-email 2.27.0 In-Reply-To: <20200724124241.48208-1-roger.pau@citrix.com> References: <20200724124241.48208-1-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 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