From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-0.8 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 73ACEC433DF for ; Mon, 22 Jun 2020 08:23:50 +0000 (UTC) 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 mail.kernel.org (Postfix) with ESMTPS id 40E8E20706 for ; Mon, 22 Jun 2020 08:23:50 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="Tx9Y6qOG" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 40E8E20706 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:60512 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1jnHk5-0001qB-IQ for qemu-devel@archiver.kernel.org; Mon, 22 Jun 2020 04:23:49 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:60712) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1jnHjS-0001PF-VW for qemu-devel@nongnu.org; Mon, 22 Jun 2020 04:23:10 -0400 Received: from us-smtp-1.mimecast.com ([205.139.110.61]:43801 helo=us-smtp-delivery-1.mimecast.com) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA1:256) (Exim 4.90_1) (envelope-from ) id 1jnHjR-0007tX-Ee for qemu-devel@nongnu.org; Mon, 22 Jun 2020 04:23:10 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1592814188; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=YTQYxwR23NJVNpU9ATdOG6Wg7zHLA4HTU8kDiazvMWc=; b=Tx9Y6qOGXiol7SlgDlt+myejCqjtIqxV3Sark1XBN6LQV+NiPPShDj2QdzLUcm5CtkpAOf QY2gtDXYy7DMIdO9KmCa/obZYL/7+1X5aeG/xAHGJMpWWuKaix3CUkYFZQrNB1Odm6Dvxd y2r60JB8Vr72DZBELUklKL4wyybogP0= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-192-aWBdsMt8MAyPXYTk5XouBA-1; Mon, 22 Jun 2020 04:23:07 -0400 X-MC-Unique: aWBdsMt8MAyPXYTk5XouBA-1 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.phx2.redhat.com [10.5.11.15]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id F2083107ACCA; Mon, 22 Jun 2020 08:23:05 +0000 (UTC) Received: from blackfin.pond.sub.org (ovpn-112-121.ams2.redhat.com [10.36.112.121]) by smtp.corp.redhat.com (Postfix) with ESMTPS id BC5A75BAEB; Mon, 22 Jun 2020 08:23:03 +0000 (UTC) Received: by blackfin.pond.sub.org (Postfix, from userid 1000) id 08775113846D; Mon, 22 Jun 2020 10:23:01 +0200 (CEST) From: Markus Armbruster To: Zhanghailiang Subject: Re: Memory leak in transfer_memory_block()? References: <87h7v9szpe.fsf@dusky.pond.sub.org> <8562bcb768514568b14788e801aee681@huawei.com> Date: Mon, 22 Jun 2020 10:23:01 +0200 In-Reply-To: <8562bcb768514568b14788e801aee681@huawei.com> (Zhanghailiang's message of "Thu, 18 Jun 2020 06:49:51 +0000") Message-ID: <87bllbpl0a.fsf@dusky.pond.sub.org> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/26.3 (gnu/linux) MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.15 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain Received-SPF: pass client-ip=205.139.110.61; envelope-from=armbru@redhat.com; helo=us-smtp-delivery-1.mimecast.com X-detected-operating-system: by eggs.gnu.org: First seen = 2020/06/22 03:17:49 X-ACL-Warn: Detected OS = Linux 2.2.x-3.x [generic] [fuzzy] X-Spam_score_int: -30 X-Spam_score: -3.1 X-Spam_bar: --- X-Spam_report: (-3.1 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-1, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H3=-0.01, RCVD_IN_MSPIKE_WL=-0.01, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=_AUTOLEARN X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: "qemu-devel@nongnu.org" , Michael Roth Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" Zhanghailiang writes: >> -----Original Message----- >> From: Markus Armbruster [mailto:armbru@redhat.com] >> Sent: Thursday, June 18, 2020 1:36 PM >> To: Zhanghailiang >> Cc: qemu-devel@nongnu.org; Michael Roth >> Subject: Memory leak in transfer_memory_block()? >> >> We appear to leak an Error object when ga_read_sysfs_file() fails with >> errno != ENOENT unless caller passes true @sys2memblk: >> >> static void transfer_memory_block(GuestMemoryBlock *mem_blk, bool >> sys2memblk, >> GuestMemoryBlockResponse >> *result, >> Error **errp) >> { >> [...] >> if (local_err) { >> >> We have an Error object. >> >> /* treat with sysfs file that not exist in old kernel */ >> if (errno == ENOENT) { >> >> Case 1: ENOENT; we free it. Good. >> >> error_free(local_err); >> if (sys2memblk) { >> mem_blk->online = true; >> mem_blk->can_offline = false; >> } else if (!mem_blk->online) { >> result->response = >> >> GUEST_MEMORY_BLOCK_RESPONSE_TYPE_OPERATION_NOT_SUPPORTED; >> } >> } else { >> >> Case 2: other than ENOENT >> >> if (sys2memblk) { >> >> Case 2a: sys2memblk; we pass it to the caller. Good. >> >> error_propagate(errp, local_err); >> } else { >> >> Case 2b: !sys2memblk; ??? >> > > Good catch! I think we should pass the error info back to the caller, > Let's record this error for debug when it happens. I'll post a minimal fix to plug the leak, cc'ing you. I'll gladly replace it by a patch that does more. Thanks! >> result->response = >> >> GUEST_MEMORY_BLOCK_RESPONSE_TYPE_OPERATION_FAILED; >> } >> } >> goto out2; >> } >> [...] >> out2: >> g_free(status); >> close(dirfd); >> out1: >> if (!sys2memblk) { >> result->has_error_code = true; >> result->error_code = errno; >> } >> } >> >> What is supposed to be done with @local_err in case 2b?