From nobody Thu Dec 18 09:32:20 2025 Delivered-To: importer@patchew.org Authentication-Results: mx.zohomail.com; spf=pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org Return-Path: Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) by mx.zohomail.com with SMTPS id 1747249695354299.4566293924048; Wed, 14 May 2025 12:08:15 -0700 (PDT) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1uFHSD-0000Bo-78; Wed, 14 May 2025 15:07:45 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1uFHN7-0005g2-TQ; Wed, 14 May 2025 15:02:32 -0400 Received: from isrv.corpit.ru ([86.62.121.231]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1uFHN2-0007k0-V7; Wed, 14 May 2025 15:02:29 -0400 Received: from tsrv.corpit.ru (tsrv.tls.msk.ru [192.168.177.2]) by isrv.corpit.ru (Postfix) with ESMTP id ED900121D9D; Wed, 14 May 2025 22:00:32 +0300 (MSK) Received: from think4mjt.tls.msk.ru (mjtthink.wg.tls.msk.ru [192.168.177.146]) by tsrv.corpit.ru (Postfix) with ESMTP id 01C3B20BA8F; Wed, 14 May 2025 22:00:43 +0300 (MSK) From: Michael Tokarev To: qemu-devel@nongnu.org Cc: qemu-stable@nongnu.org, Aleksandr Partanen , Stefano Stabellini , "Edgar E . Iglesias" , Michael Tokarev Subject: [Stable-10.0.1 19/23] xen: mapcache: Fix finding matching entry Date: Wed, 14 May 2025 22:00:31 +0300 Message-Id: <20250514190041.104759-19-mjt@tls.msk.ru> X-Mailer: git-send-email 2.39.5 In-Reply-To: References: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Received-SPF: pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) client-ip=209.51.188.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Received-SPF: pass client-ip=86.62.121.231; envelope-from=mjt@tls.msk.ru; helo=isrv.corpit.ru X-Spam_score_int: -68 X-Spam_score: -6.9 X-Spam_bar: ------ X-Spam_report: (-6.9 / 5.0 requ) BAYES_00=-1.9, RCVD_IN_DNSWL_HI=-5, RCVD_IN_VALIDITY_CERTIFIED_BLOCKED=0.001, RCVD_IN_VALIDITY_RPBL_BLOCKED=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: qemu-devel-bounces+importer=patchew.org@nongnu.org X-ZM-MESSAGEID: 1747249695859019000 Content-Type: text/plain; charset="utf-8" From: Aleksandr Partanen If we have request without lock and hit unlocked or invalid entry during the search, we remap it immediately, even if we have matching entry in next entries in bucket. This leads to duplication of mappings of the same size, and to possibility of selecting the wrong element during invalidation and underflow it's entry->lock counter Signed-off-by: Aleksandr Partanen Reviewed-by: Stefano Stabellini Reviewed-by: Edgar E. Iglesias Signed-off-by: Edgar E. Iglesias (cherry picked from commit a4b20f737cda06bb8706a83e27f7fa89863ae689) Signed-off-by: Michael Tokarev diff --git a/hw/xen/xen-mapcache.c b/hw/xen/xen-mapcache.c index 698b5c53ed..2c8f861fdb 100644 --- a/hw/xen/xen-mapcache.c +++ b/hw/xen/xen-mapcache.c @@ -376,12 +376,12 @@ tryagain: =20 entry =3D &mc->entry[address_index % mc->nr_buckets]; =20 - while (entry && (lock || entry->lock) && entry->vaddr_base && - (entry->paddr_index !=3D address_index || entry->size !=3D cac= he_size || + while (entry && (!entry->vaddr_base || + entry->paddr_index !=3D address_index || entry->size !=3D cach= e_size || !test_bits(address_offset >> XC_PAGE_SHIFT, test_bit_size >> XC_PAGE_SHIFT, entry->valid_mapping))) { - if (!free_entry && !entry->lock) { + if (!free_entry && (!entry->lock || !entry->vaddr_base)) { free_entry =3D entry; free_pentry =3D pentry; } --=20 2.39.5