From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from lists1p.gnu.org (lists1p.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-ECDSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 9B14B606A31F for ; Mon, 26 Oct 2026 14:33:21 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key, unprotected) header.d=redhat.com header.i=@redhat.com header.a=rsa-sha256 header.s=mimecast20190719 header.b=PxK64yqW Received: from localhost ([::1] helo=lists1p.gnu.org) by lists1p.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1xLLl4-0000Sm-88; Mon, 26 Oct 2026 10:33:06 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists1p.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1xLLky-0000S7-1Y for qemu-devel@nongnu.org; Mon, 26 Oct 2026 10:33:00 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.129.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1xLLkw-0004wZ-7s for qemu-devel@nongnu.org; Mon, 26 Oct 2026 10:32:59 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1793025176; h=from:from:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=lFgtAdEzpDXY9TbSXCOM+3EHKc2abrC6riAv1d5BnjE=; b=PxK64yqWBD3e4y3a3QXzi4aKBtj28hlgmUYX502Nj4qhC1D122L+T6T6tqKputHos373jy BgQ9T6aCgSZVmx0qQCuPqrCQEExqC3Y/0rEMos/r+3yzV/8/h5w9Yqapp1NQOcQf+GgqNr 4T+SFoFi4rOoDk4Rh3Dqyr+EVPmOLKU= Received: from mx-prod-mc-01.mail-002.prod.us-west-2.aws.redhat.com (ec2-54-186-198-63.us-west-2.compute.amazonaws.com [54.186.198.63]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-159-Dpnqsa_gM2OkjAnnHc-w7g-1; Mon, 26 Oct 2026 10:32:55 -0400 X-MC-Unique: Dpnqsa_gM2OkjAnnHc-w7g-1 X-Mimecast-MFC-AGG-ID: Dpnqsa_gM2OkjAnnHc-w7g_1793025174 Received: from mx-prod-int-10.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-10.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.95]) (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 mx-prod-mc-01.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 38D3E195395E; Mon, 26 Oct 2026 14:32:54 +0000 (UTC) Received: from redhat.com (headnet04.pony-001.prod.iad2.dc.redhat.com [10.2.32.116]) by mx-prod-int-10.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id C121D41B; Mon, 26 Oct 2026 14:32:52 +0000 (UTC) Date: Mon, 26 Oct 2026 14:32:49 +0000 From: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= To: Markus Armbruster Cc: qemu-devel@nongnu.org, Fabiano Rosas , Paolo Bonzini , Laurent Vivier Subject: Re: [PATCH] qtest: ensure socket_accept() return value is initialized Message-ID: References: <20261026124043.770095-1-berrange@redhat.com> <87ik2od0tj.fsf@pond.sub.org> X-Archived-By: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <87ik2od0tj.fsf@pond.sub.org> User-Agent: Mutt/2.4.2 (2026-08-30) X-Scanned-By: MIMEDefang 3.6 on 10.30.177.95 Received-SPF: pass client-ip=170.10.129.124; envelope-from=berrange@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: 2 X-Spam_score: 0.2 X-Spam_bar: / X-Spam_report: (0.2 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.339, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_LOW=-0.7, RCVD_IN_SBL_CSS=3.335, SPF_HELO_PASS=-0.001, SPF_PASS=-0.001 autolearn=no autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: qemu development List-Archive: List-Post: List-Help: List-Subscribe: , Reply-To: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org X-Spam-Status: No, score=-17.6 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_PASS, SPF_PASS,USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=4.0.1 X-Spam-Checker-Version: SpamAssassin 4.0.1 (2024-03-26) on aws-us-west-2-korg-listserv-alma10-1 On Mon, Oct 26, 2026 at 02:54:32PM +0100, Markus Armbruster wrote: > Daniel P. Berrangé writes: > > > If the very first iteration of the loop breaks early due to the > > dead QEMU process, 'ret' is never initialized. Ensure it is set > > to -1 to represent an invalid FD number. > > > > CID 1688281 > > Reported-by: Markus Armbruster > > Fixes: c12ad5378739 (qtest: fail fast when QEMU terminates early) > > Signed-off-by: Daniel P. Berrangé > > --- > > tests/qtest/libqtest.c | 2 +- > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > diff --git a/tests/qtest/libqtest.c b/tests/qtest/libqtest.c > > index 9e7a2d43a18..899727d6d35 100644 > > --- a/tests/qtest/libqtest.c > > +++ b/tests/qtest/libqtest.c > > @@ -121,7 +121,7 @@ static int qtest_socket_accept(QTestState *s, int sock) > > { > > struct sockaddr_un addr; > > socklen_t addrlen; > > - int ret; > > + int ret = -1; > > size_t i; > > #ifndef _WIN32 > > struct timeval timeout = { .tv_sec = 0, > > Hmm, we do the same thing in several different ways: > > static int qtest_socket_accept(QTestState *s, int sock) > { > struct sockaddr_un addr; > socklen_t addrlen; > int ret; > size_t i; > #ifndef _WIN32 > struct timeval timeout = { .tv_sec = 0, > .tv_usec = ACCEPT_TIMEOUT_MS * 1000ul }; > #else > DWORD timeout = ACCEPT_TIMEOUT_MS; > #endif > > if (setsockopt(sock, SOL_SOCKET, SO_RCVTIMEO, > (void *)&timeout, sizeof(timeout))) { > fprintf(stderr, "%s failed to set SO_RCVTIMEO: %s\n", > __func__, strerror(errno)); > close(sock); > return -1; > > (A) Free resources and return failure. > > } > > for (i = 0; i < ACCEPT_RETRIES ; i++) { > if (!qtest_probe_child(s)) { > fprintf(stderr, > "child process unexpectedly exited, skipping socket accept\n"); > goto cleanup; > > (B) Jump to exit, where we free resources and return @ret. > > } > > addrlen = sizeof(addr); > ret = accept(sock, (struct sockaddr *)&addr, &addrlen); > if (ret == -1) { > if (errno == EINTR || errno == EAGAIN) { > continue; > } else { > fprintf(stderr, "%s failed: %s\n", __func__, strerror(errno)); > } > } > > (C) Return @ret. > > Hmm, should we close(sock) on failure here? Opps, yes, you are right - we should in fact fall through to the cleanup: label, as the intention is 'sock' is closed in all, as the caller expects socket_accept() to close the sock in all cases. That's a second bug in my original patch. This is pretty unpleasant semantics though - the caller owns the socket and should own closing it. > return ret; > } > > cleanup: > close(sock); > > return ret; > } > > All three ways can work fine. But using all three next to each other I > find somewhat grating. Matter of taste. I'm not demanding you change > this. > With regards, Daniel -- |: https://berrange.com ~~ https://hachyderm.io/@berrange :| |: https://libvirt.org ~~ https://entangle-photo.org :| |: https://pixelfed.art/berrange ~~ https://fstop138.berrange.com :|