From patchwork Fri Aug 11 15:08:28 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Fabiano Rosas X-Patchwork-Id: 1820314 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@legolas.ozlabs.org Authentication-Results: legolas.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=nongnu.org (client-ip=209.51.188.17; helo=lists.gnu.org; envelope-from=qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org; receiver=) Authentication-Results: legolas.ozlabs.org; dkim=pass (1024-bit key; unprotected) header.d=suse.de header.i=@suse.de header.a=rsa-sha256 header.s=susede2_rsa header.b=cndRm/K5; dkim=pass header.d=suse.de header.i=@suse.de header.a=ed25519-sha256 header.s=susede2_ed25519 header.b=FDVhUdw/; dkim-atps=neutral Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-ECDSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by legolas.ozlabs.org (Postfix) with ESMTPS id 4RMnJF2SY5z1yfH for ; Sat, 12 Aug 2023 01:09:17 +1000 (AEST) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1qUTkw-0000Ye-Te; Fri, 11 Aug 2023 11:08:51 -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 1qUTks-0000XS-Sv for qemu-devel@nongnu.org; Fri, 11 Aug 2023 11:08:47 -0400 Received: from smtp-out2.suse.de ([195.135.220.29]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1qUTkr-0006Gy-79 for qemu-devel@nongnu.org; Fri, 11 Aug 2023 11:08:46 -0400 Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by smtp-out2.suse.de (Postfix) with ESMTPS id E09CF1F890; Fri, 11 Aug 2023 15:08:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_rsa; t=1691766523; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=oeOxeNBC49de/luEiFl9+VCrPoWsGucZKKBRosGSJO4=; b=cndRm/K5Udro8ct25MNmtZmJ5Q/TmsVy5FwYz84BkAEg2QHDl6RgdHdlA1BlpoPQmX/B0Q v1qv14zByIFmzqYKff8ZVgDOyFI5/sO2wvmPfPavu3gyuSp4ivZZWd3q1f00QmAinugFxI Bui2ffv0z3hQ1FWGT0PydLotxfp4jJ0= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_ed25519; t=1691766523; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=oeOxeNBC49de/luEiFl9+VCrPoWsGucZKKBRosGSJO4=; b=FDVhUdw/fRKr/I4EWNwjEF1x3jwoWUofrVEITheRY9hj5WRlzw+xPElVEn4ltyUkr2INV3 JMhiinxGmjkv4YDQ== Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by imap2.suse-dmz.suse.de (Postfix) with ESMTPS id 611FB13592; Fri, 11 Aug 2023 15:08:42 +0000 (UTC) Received: from dovecot-director2.suse.de ([192.168.254.65]) by imap2.suse-dmz.suse.de with ESMTPSA id MEvFCvpO1mS7KwAAMHmgww (envelope-from ); Fri, 11 Aug 2023 15:08:42 +0000 From: Fabiano Rosas To: qemu-devel@nongnu.org Cc: Juan Quintela , Peter Xu , Wei Wang , Leonardo Bras Subject: [PATCH v3 02/10] migration: Fix possible race when shutting return path Date: Fri, 11 Aug 2023 12:08:28 -0300 Message-Id: <20230811150836.2895-3-farosas@suse.de> X-Mailer: git-send-email 2.35.3 In-Reply-To: <20230811150836.2895-1-farosas@suse.de> References: <20230811150836.2895-1-farosas@suse.de> MIME-Version: 1.0 Received-SPF: pass client-ip=195.135.220.29; envelope-from=farosas@suse.de; helo=smtp-out2.suse.de X-Spam_score_int: -43 X-Spam_score: -4.4 X-Spam_bar: ---- X-Spam_report: (-4.4 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_MED=-2.3, 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+incoming=patchwork.ozlabs.org@nongnu.org Sender: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org We cannot call qemu_file_shutdown() on the return path file without taking the file lock. The return path thread could be running it's cleanup code and have just cleared the pointer. This was caught by inspection, it should be rare, but the next patches will start calling this code from other places, so let's do the correct thing. Signed-off-by: Fabiano Rosas --- migration/migration.c | 20 +++++++++++--------- 1 file changed, 11 insertions(+), 9 deletions(-) diff --git a/migration/migration.c b/migration/migration.c index f88c86079c..0067c927fa 100644 --- a/migration/migration.c +++ b/migration/migration.c @@ -2052,17 +2052,19 @@ static int open_return_path_on_source(MigrationState *ms, static int await_return_path_close_on_source(MigrationState *ms) { /* - * If this is a normal exit then the destination will send a SHUT and the - * rp_thread will exit, however if there's an error we need to cause - * it to exit. + * If this is a normal exit then the destination will send a SHUT + * and the rp_thread will exit, however if there's an error we + * need to cause it to exit. shutdown(2), if we have it, will + * cause it to unblock if it's stuck waiting for the destination. */ - if (qemu_file_get_error(ms->to_dst_file) && ms->rp_state.from_dst_file) { - /* - * shutdown(2), if we have it, will cause it to unblock if it's stuck - * waiting for the destination. - */ - qemu_file_shutdown(ms->rp_state.from_dst_file); + if (qemu_file_get_error(ms->to_dst_file)) { + WITH_QEMU_LOCK_GUARD(&ms->qemu_file_lock) { + if (ms->rp_state.from_dst_file) { + qemu_file_shutdown(ms->rp_state.from_dst_file); + } + } } + trace_await_return_path_close_on_source_joining(); qemu_thread_join(&ms->rp_state.rp_thread); ms->rp_state.rp_thread_created = false;