From patchwork Sat Nov 9 12:07:32 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Michael Tokarev X-Patchwork-Id: 13869446 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 68DE1D5E367 for ; Sat, 9 Nov 2024 12:12:26 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1t9kKB-0007Uc-Fz; Sat, 09 Nov 2024 07:12:19 -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 1t9kIa-00049J-I7; Sat, 09 Nov 2024 07:10:41 -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 1t9kIY-0004JT-TZ; Sat, 09 Nov 2024 07:10:40 -0500 Received: from tsrv.corpit.ru (tsrv.tls.msk.ru [192.168.177.2]) by isrv.corpit.ru (Postfix) with ESMTP id 8939AA1606; Sat, 9 Nov 2024 15:07:08 +0300 (MSK) Received: from tls.msk.ru (mjt.wg.tls.msk.ru [192.168.177.130]) by tsrv.corpit.ru (Postfix) with SMTP id 4FBD5167F94; Sat, 9 Nov 2024 15:08:03 +0300 (MSK) Received: (nullmailer pid 3295345 invoked by uid 1000); Sat, 09 Nov 2024 12:08:01 -0000 From: Michael Tokarev To: qemu-devel@nongnu.org Cc: qemu-stable@nongnu.org, Ilya Leoshkevich , Laurent Vivier , Richard Henderson , Michael Tokarev Subject: [Stable-9.0.4 30/57] linux-user: Emulate /proc/self/maps under mmap_lock Date: Sat, 9 Nov 2024 15:07:32 +0300 Message-Id: <20241109120801.3295120-30-mjt@tls.msk.ru> X-Mailer: git-send-email 2.39.5 In-Reply-To: References: MIME-Version: 1.0 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+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org 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_maps") 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-g59272469bd13 "user: Use get_task_state() helper") diff --git a/linux-user/syscall.c b/linux-user/syscall.c index 2edbd1ef15..caa91c3b1d 100644 --- a/linux-user/syscall.c +++ b/linux-user/syscall.c @@ -8132,17 +8132,19 @@ static int open_self_maps_1(CPUArchState *env, int fd, bool smaps) { struct open_self_maps_data d = { .ts = env_cpu(env)->opaque, - .host_maps = read_self_maps(), .fd = fd, .smaps = smaps }; + mmap_lock(); + d.host_maps = 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; }