From nobody Sat Nov 23 21:54:36 2024 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 173114783529157.9514900683904; Sat, 9 Nov 2024 02:23:55 -0800 (PST) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1t9iZE-0003ML-Em; Sat, 09 Nov 2024 05:19:48 -0500 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 1t9iWT-0006Ii-O9; Sat, 09 Nov 2024 05:16:56 -0500 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 1t9iWS-00080V-0s; Sat, 09 Nov 2024 05:16:53 -0500 Received: from tsrv.corpit.ru (tsrv.tls.msk.ru [192.168.177.2]) by isrv.corpit.ru (Postfix) with ESMTP id 95940A13FE; Sat, 9 Nov 2024 13:13:50 +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 3E050167EE9; Sat, 9 Nov 2024 13:14:45 +0300 (MSK) From: Michael Tokarev To: qemu-devel@nongnu.org Cc: qemu-stable@nongnu.org, Ilya Leoshkevich , Laurent Vivier , Richard Henderson , Michael Tokarev Subject: [Stable-8.2.8 25/49] linux-user: Emulate /proc/self/maps under mmap_lock Date: Sat, 9 Nov 2024 13:14:16 +0300 Message-Id: <20241109101443.312701-25-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: 1731147836370116600 Content-Type: text/plain; charset="utf-8" From: Ilya Leoshkevich If one thread modifies the mappings and another thread prints them, a situation may occur that the printer thread sees a guest mapping without a corresponding host mapping, leading to a crash in open_self_maps_2(). Cc: qemu-stable@nongnu.org Fixes: 7b7a3366e142 ("linux-user: Use walk_memory_regions for open_self_map= s") Signed-off-by: Ilya Leoshkevich Reviewed-by: Laurent Vivier Reviewed-by: Richard Henderson Message-ID: <20241014203441.387560-1-iii@linux.ibm.com> Signed-off-by: Richard Henderson (cherry picked from commit bbd5630a75e70a0f1bcf04de74c94aa94a145628) Signed-off-by: Michael Tokarev (Mjt: context fix in linux-user/syscall.c due to missing v9.0.0-421-g592724= 69bd13 "user: Use get_task_state() helper") diff --git a/linux-user/syscall.c b/linux-user/syscall.c index d9212aa966..e178366093 100644 --- a/linux-user/syscall.c +++ b/linux-user/syscall.c @@ -8120,17 +8120,19 @@ static int open_self_maps_1(CPUArchState *env, int = fd, bool smaps) { struct open_self_maps_data d =3D { .ts =3D env_cpu(env)->opaque, - .host_maps =3D read_self_maps(), .fd =3D fd, .smaps =3D smaps }; =20 + mmap_lock(); + d.host_maps =3D read_self_maps(); if (d.host_maps) { walk_memory_regions(&d, open_self_maps_2); free_self_maps(d.host_maps); } else { walk_memory_regions(&d, open_self_maps_3); } + mmap_unlock(); return 0; } =20 --=20 2.39.5