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 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 E1965C4167B for ; Thu, 30 Nov 2023 07:10:43 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1r8bBM-0003nO-T2; Thu, 30 Nov 2023 02:09:56 -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 1r8bBK-0003nA-VL for qemu-devel@nongnu.org; Thu, 30 Nov 2023 02:09:55 -0500 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1r8bBJ-00007Q-3M for qemu-devel@nongnu.org; Thu, 30 Nov 2023 02:09:54 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1701328191; 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=B5jMznOcmZIjXjINNROHEylog8pC9eJMqhfpCclJlTg=; b=hCmH1EbLPgb0NDrVMByUjxqzA/KAgxbf5Xeuqh0vaAdP+4hoZlEqG3R4Iuu+V+5Qog0N6C z6ap8VgvBAXLyBgO+aWVLC2WJIJeq5KcNbPIO/VQNYQZrlptJ7hG8zFi8wgrvwUx6qZqcl wyyZhYtrrfRMYsNfmjuamejbd9oAzLI= Received: from mimecast-mx02.redhat.com (mx-ext.redhat.com [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-618-IoBmG_6oN6SRy8tOubcJIw-1; Thu, 30 Nov 2023 02:09:50 -0500 X-MC-Unique: IoBmG_6oN6SRy8tOubcJIw-1 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.rdu2.redhat.com [10.11.54.2]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 033BD1C18CCD; Thu, 30 Nov 2023 07:09:50 +0000 (UTC) Received: from blackfin.pond.sub.org (unknown [10.39.192.148]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 9206C40C6EB9; Thu, 30 Nov 2023 07:09:49 +0000 (UTC) Received: by blackfin.pond.sub.org (Postfix, from userid 1000) id 81CFF21E6A1F; Thu, 30 Nov 2023 08:09:48 +0100 (CET) From: Markus Armbruster To: Het Gala Cc: qemu-devel@nongnu.org, prerna.saxena@nutanix.com, quintela@redhat.com, berrange@redhat.com, peter.maydell@linaro.org, farosas@suse.de Subject: Re: [PATCH v3] migration: free 'channel' after its use in migration.c References: <20231129080624.161578-1-het.gala@nutanix.com> <87fs0ok9i1.fsf@pond.sub.org> <80e9331a-0691-4bd1-8589-a78c2814e627@nutanix.com> Date: Thu, 30 Nov 2023 08:09:48 +0100 In-Reply-To: <80e9331a-0691-4bd1-8589-a78c2814e627@nutanix.com> (Het Gala's message of "Thu, 30 Nov 2023 02:07:26 +0530") Message-ID: <878r6fg1j7.fsf@pond.sub.org> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/28.2 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain X-Scanned-By: MIMEDefang 3.4.1 on 10.11.54.2 Received-SPF: pass client-ip=170.10.133.124; envelope-from=armbru@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.001, 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=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, T_SCC_BODY_TEXT_LINE=-0.01 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 Het Gala writes: > On 29/11/23 6:21 pm, Markus Armbruster wrote: >> I'ld like to suggest a clearer subject: >> >> migration: Plug memory leak with migration URIs > Ack. Will update the commit message >> Het Gala writes: >> >>> 'channel' in qmp_migrate() and qmp_migrate_incoming() is not >>> auto-freed. migrate_uri_parse() allocates memory to 'channel' if >> >> Not sure we need the first sentence. QMP commands never free their >> arguments. > > Ack. > >>> the user opts for old syntax - uri, which is leaked because there >>> is no code for freeing 'channel'. >>> So, free channel to avoid memory leak in case where 'channels' >>> is empty and uri parsing is required. >>> Fixes: 5994024f ("migration: Implement MigrateChannelList to qmp >>> migration flow") >>> >>> Signed-off-by: Het Gala >>> Suggested-by: Markus Armbruster >> >> Keep the Fixes: tag on a single line, and next to the other tags: >> >> [...] >> is empty and uri parsing is required. >> >> Fixes: 5994024f ("migration: Implement MigrateChannelList to qmp migration flow") >> Signed-off-by: Het Gala >> Suggested-by: Markus Armbruster > > Ack. > > [...] > >>> + addr = channels->value->addr; >>> } else if (uri) { >>> /* caller uses the old URI syntax */ >>> if (!migrate_uri_parse(uri, &channel, errp)) { >>> return; >>> } >>> + addr = channel->addr; >>> } else { >>> error_setg(errp, "neither 'uri' or 'channels' argument are " >>> "specified in 'migrate' qmp command "); >>> return; >>> } >>> - addr = channel->addr; >>> /* transport mechanism not suitable for migration? */ >>> if (!migration_channels_and_transport_compatible(addr, errp)) { >> >> I tested this with an --enable-santizers build. Before the patch: >> >> $ qemu-system-x86_64 -nodefaults -S -display none -monitor stdio -incoming unix:123 >> ==3260873==WARNING: ASan doesn't fully support makecontext/swapcontext functions and may produce false positives in some cases! >> QEMU 8.1.92 monitor - type 'help' for more information >> (qemu) q >> >> ================================================================= >> ==3260873==ERROR: LeakSanitizer: detected memory leaks >> >> Direct leak of 40 byte(s) in 1 object(s) allocated from: >> #0 0x7f0ba08ba097 in calloc (/lib64/libasan.so.8+0xba097) >> #1 0x7f0b9f4eb5b0 in g_malloc0 (/lib64/libglib-2.0.so.0+0x5f5b0) >> #2 0x55b446454dbe in migrate_uri_parse ../migration/migration.c:490 >> #3 0x55b4464557c9 in qemu_start_incoming_migration ../migration/migration.c:539 >> #4 0x55b446461687 in qmp_migrate_incoming ../migration/migration.c:1734 >> #5 0x55b4463df1c2 in qmp_x_exit_preconfig ../system/vl.c:2718 >> #6 0x55b4463e4d8e in qemu_init ../system/vl.c:3753 >> #7 0x55b446f63ca9 in main ../system/main.c:47 >> #8 0x7f0b9d04a54f in __libc_start_call_main (/lib64/libc.so.6+0x2754f) >> >> Direct leak of 16 byte(s) in 1 object(s) allocated from: >> #0 0x7f0ba08ba097 in calloc (/lib64/libasan.so.8+0xba097) >> #1 0x7f0b9f4eb5b0 in g_malloc0 (/lib64/libglib-2.0.so.0+0x5f5b0) >> #2 0x55b4464557c9 in qemu_start_incoming_migration ../migration/migration.c:539 >> #3 0x55b446461687 in qmp_migrate_incoming ../migration/migration.c:1734 >> #4 0x55b4463df1c2 in qmp_x_exit_preconfig ../system/vl.c:2718 >> #5 0x55b4463e4d8e in qemu_init ../system/vl.c:3753 >> #6 0x55b446f63ca9 in main ../system/main.c:47 >> #7 0x7f0b9d04a54f in __libc_start_call_main (/lib64/libc.so.6+0x2754f) >> >> Direct leak of 8 byte(s) in 1 object(s) allocated from: >> #0 0x7f0ba08bb1a8 in operator new(unsigned long) (/lib64/libasan.so.8+0xbb1a8) >> #1 0x7f0b9a9255b7 in _sub_I_65535_0.0 (/lib64/libtcmalloc_minimal.so.4+0xe5b7) >> >> Indirect leak of 48 byte(s) in 1 object(s) allocated from: >> #0 0x7f0ba08ba097 in calloc (/lib64/libasan.so.8+0xba097) >> #1 0x7f0b9f4eb5b0 in g_malloc0 (/lib64/libglib-2.0.so.0+0x5f5b0) >> #2 0x55b4464557c9 in qemu_start_incoming_migration ../migration/migration.c:539 >> #3 0x55b446461687 in qmp_migrate_incoming ../migration/migration.c:1734 >> #4 0x55b4463df1c2 in qmp_x_exit_preconfig ../system/vl.c:2718 >> #5 0x55b4463e4d8e in qemu_init ../system/vl.c:3753 >> #6 0x55b446f63ca9 in main ../system/main.c:47 >> #7 0x7f0b9d04a54f in __libc_start_call_main (/lib64/libc.so.6+0x2754f) >> >> Indirect leak of 4 byte(s) in 1 object(s) allocated from: >> #0 0x7f0ba08ba6af in __interceptor_malloc (/lib64/libasan.so.8+0xba6af) >> #1 0x7f0b9f4eb128 in g_malloc (/lib64/libglib-2.0.so.0+0x5f128) >> >> SUMMARY: AddressSanitizer: 116 byte(s) leaked in 5 allocation(s). > > curious: how to get this stack trace ? I tried to configure and build qemu with --enable-santizers option, but on running the tests 'make -j test', I see: > > ==226453==LeakSanitizer has encountered a fatal error. ==226453==HINT: For debugging, try setting environment variable LSAN_OPTIONS=verbosity=1:log_threads=1 ==226453==HINT: LeakSanitizer does not work under ptrace (strace, gdb, etc) I built with $ ../configure --disable-werror --target-list=x86_64-softmmu --enable-debug --enable-sanitizers $ make then ran the manual test shown above. "make check" fails differently for me than it does for you. [...]