From patchwork Tue Jul 16 11:05:50 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Paul Durrant X-Patchwork-Id: 11045853 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id A593E1510 for ; Tue, 16 Jul 2019 11:07:23 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 93EDF28508 for ; Tue, 16 Jul 2019 11:07:23 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 86A7228564; Tue, 16 Jul 2019 11:07:23 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.2 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_MED autolearn=ham version=3.3.1 Received: from lists.xenproject.org (lists.xenproject.org [192.237.175.120]) (using TLSv1.2 with cipher AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 2488828541 for ; Tue, 16 Jul 2019 11:07:23 +0000 (UTC) Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.89) (envelope-from ) id 1hnLHS-0002v1-G1; Tue, 16 Jul 2019 11:05:58 +0000 Received: from us1-rack-dfw2.inumbo.com ([104.130.134.6]) by lists.xenproject.org with esmtp (Exim 4.89) (envelope-from ) id 1hnLHQ-0002uw-D4 for xen-devel@lists.xenproject.org; Tue, 16 Jul 2019 11:05:56 +0000 X-Inumbo-ID: ae67452a-a7b9-11e9-8980-bc764e045a96 Received: from esa2.hc3370-68.iphmx.com (unknown [216.71.145.153]) by us1-rack-dfw2.inumbo.com (Halon) with ESMTPS id ae67452a-a7b9-11e9-8980-bc764e045a96; Tue, 16 Jul 2019 11:05:55 +0000 (UTC) Authentication-Results: esa2.hc3370-68.iphmx.com; dkim=none (message not signed) header.i=none; spf=None smtp.pra=paul.durrant@citrix.com; spf=Pass smtp.mailfrom=Paul.Durrant@citrix.com; spf=None smtp.helo=postmaster@mail.citrix.com Received-SPF: None (esa2.hc3370-68.iphmx.com: no sender authenticity information available from domain of paul.durrant@citrix.com) identity=pra; client-ip=162.221.158.21; receiver=esa2.hc3370-68.iphmx.com; envelope-from="Paul.Durrant@citrix.com"; x-sender="paul.durrant@citrix.com"; x-conformance=sidf_compatible Received-SPF: Pass (esa2.hc3370-68.iphmx.com: domain of Paul.Durrant@citrix.com designates 162.221.158.21 as permitted sender) identity=mailfrom; client-ip=162.221.158.21; receiver=esa2.hc3370-68.iphmx.com; envelope-from="Paul.Durrant@citrix.com"; x-sender="Paul.Durrant@citrix.com"; x-conformance=sidf_compatible; x-record-type="v=spf1"; x-record-text="v=spf1 ip4:209.167.231.154 ip4:178.63.86.133 ip4:195.66.111.40/30 ip4:85.115.9.32/28 ip4:199.102.83.4 ip4:192.28.146.160 ip4:192.28.146.107 ip4:216.52.6.88 ip4:216.52.6.188 ip4:162.221.158.21 ip4:162.221.156.83 ~all" Received-SPF: None (esa2.hc3370-68.iphmx.com: no sender authenticity information available from domain of postmaster@mail.citrix.com) identity=helo; client-ip=162.221.158.21; receiver=esa2.hc3370-68.iphmx.com; envelope-from="Paul.Durrant@citrix.com"; x-sender="postmaster@mail.citrix.com"; x-conformance=sidf_compatible IronPort-SDR: qx2Ffp2BsDuZr89ee68ZrXDGg7zdCwaMHWHskT5i+iwHez1nAFLR5H/rEhc7JsFjlx5RIanM0H im/sNNYO+rDTYsXsLl1T8gcYdHKXEe+57Ha450c2NsgIZ7ULNnOvhvxC+FNJk0OaLLTRL1sgch CDEbgSkZ0LMVYqBWGY3wbCsl7Q39HI/O+j79UbtdQ6Siwg/8UGEx6qV75twlvWnFE9UEUEBmOF 3X+jOqtfz8cj6AkBonSdQaEJjiDkZODpIKoLTojoMcRFIaUj3l2LSkmNro8OxHOHzbGm4KqE7P jrg= X-SBRS: 2.7 X-MesageID: 3007977 X-Ironport-Server: esa2.hc3370-68.iphmx.com X-Remote-IP: 162.221.158.21 X-Policy: $RELAYED X-IronPort-AV: E=Sophos;i="5.63,498,1557201600"; d="scan'208";a="3007977" From: Paul Durrant To: Date: Tue, 16 Jul 2019 12:05:50 +0100 Message-ID: <20190716110550.19086-1-paul.durrant@citrix.com> X-Mailer: git-send-email 2.20.1.2.gb21ebb671 MIME-Version: 1.0 Subject: [Xen-devel] [PATCH] mm.h: fix BUG_ON() condition in put_page_alloc_ref() X-BeenThere: xen-devel@lists.xenproject.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Cc: Stefano Stabellini , Wei Liu , Konrad Rzeszutek Wilk , George Dunlap , Andrew Cooper , Ian Jackson , Tim Deegan , Julien Grall , Paul Durrant , Jan Beulich Errors-To: xen-devel-bounces@lists.xenproject.org Sender: "Xen-devel" X-Virus-Scanned: ClamAV using ClamSMTP The BUG_ON() was misplaced when this function was introduced in commit ec83f825 "mm.h: add helper function to test-and-clear _PGC_allocated". It will fire incorrectly if _PGC_allocated is already clear on entry. Thus it should be moved after the if statement. Signed-off-by: Paul Durrant Reviewed-by: Jan Beulich --- Cc: Andrew Cooper Cc: George Dunlap Cc: Ian Jackson Cc: Jan Beulich Cc: Julien Grall Cc: Konrad Rzeszutek Wilk Cc: Stefano Stabellini Cc: Tim Deegan Cc: Wei Liu --- xen/include/xen/mm.h | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/xen/include/xen/mm.h b/xen/include/xen/mm.h index 5d0c19f011..cfea38f801 100644 --- a/xen/include/xen/mm.h +++ b/xen/include/xen/mm.h @@ -667,9 +667,11 @@ static inline void put_page_alloc_ref(struct page_info *page) * the caller holding an additional reference. I.e. the allocation * reference must never be the last reference held. */ - BUG_ON((page->count_info & PGC_count_mask) <= 1); if ( test_and_clear_bit(_PGC_allocated, &page->count_info) ) + { + BUG_ON((page->count_info & PGC_count_mask) <= 1); put_page(page); + } } #endif /* __XEN_MM_H__ */