From patchwork Wed Oct 11 09:21:38 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Juan Quintela X-Patchwork-Id: 13417001 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 909E9CD6E54 for ; Wed, 11 Oct 2023 09:34:33 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1qqVRP-0001j9-Ew; Wed, 11 Oct 2023 05:23:43 -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 1qqVRN-0001hD-GI for qemu-devel@nongnu.org; Wed, 11 Oct 2023 05:23:41 -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 1qqVRL-00054u-TC for qemu-devel@nongnu.org; Wed, 11 Oct 2023 05:23:41 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1697016219; h=from:from:reply-to:subject:subject: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=9nzf9h501CnrBsSraqlerv5Ta99Pfe8Cmh4XFxpF8UE=; b=TwUsC14jn5VyFpJCr98navvwtXK3tBymRd1c0ZAXGktdnE9OOUjIItB+tCpmFZG4xRGbVZ iEbK7rbktqd7XDbE8Ns588beJdYQlpqjnx02u9271t/l9kseqNp5T3MY9sXT7WoBp0ugxp 6sJJHewpnQWCTLk5z0a0BJhCPFzmqsA= Received: from mimecast-mx02.redhat.com (mx-ext.redhat.com [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-657-k3TC6G4XNn-jub_Hdn9Egw-1; Wed, 11 Oct 2023 05:23:27 -0400 X-MC-Unique: k3TC6G4XNn-jub_Hdn9Egw-1 Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.rdu2.redhat.com [10.11.54.7]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 75F401C0896C; Wed, 11 Oct 2023 09:23:27 +0000 (UTC) Received: from secure.mitica (unknown [10.39.195.75]) by smtp.corp.redhat.com (Postfix) with ESMTP id B29E41C060B0; Wed, 11 Oct 2023 09:23:25 +0000 (UTC) From: Juan Quintela To: qemu-devel@nongnu.org Cc: Laurent Vivier , Peter Xu , Paolo Bonzini , Markus Armbruster , Juan Quintela , Thomas Huth , Li Zhijian , Leonardo Bras , Eric Blake , Fabiano Rosas Subject: [PULL 40/65] migration/rdma: Fix error handling around rdma_getaddrinfo() Date: Wed, 11 Oct 2023 11:21:38 +0200 Message-ID: <20231011092203.1266-41-quintela@redhat.com> In-Reply-To: <20231011092203.1266-1-quintela@redhat.com> References: <20231011092203.1266-1-quintela@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.4.1 on 10.11.54.7 Received-SPF: pass client-ip=170.10.129.124; envelope-from=quintela@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_H4=0.001, RCVD_IN_MSPIKE_WL=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: Markus Armbruster qemu_rdma_resolve_host() and qemu_rdma_dest_init() iterate over addresses to find one that works, holding onto the first Error from qemu_rdma_broken_ipv6_kernel() for use when no address works. Issues: 1. If @errp was &error_abort or &error_fatal, we'd terminate instead of trying the next address. Can't actually happen, since no caller passes these arguments. 2. When @errp is a pointer to a variable containing NULL, and qemu_rdma_broken_ipv6_kernel() fails, the variable no longer contains NULL. Subsequent iterations pass it again, violating Error usage rules. Dangerous, as setting an error would then trip error_setv()'s assertion. Works only because qemu_rdma_broken_ipv6_kernel() and the code following the loops carefully avoids setting a second error. 3. If qemu_rdma_broken_ipv6_kernel() fails, and then a later iteration finds a working address, @errp still holds the first error from qemu_rdma_broken_ipv6_kernel(). If we then run into another error, we report the qemu_rdma_broken_ipv6_kernel() failure instead. 4. If we don't run into another error, we leak the Error object. Use a local error variable, and propagate to @errp. This fixes 3. and also cleans up 1 and partly 2. Free this error when we have a working address. This fixes 4. Pass the local error variable to qemu_rdma_broken_ipv6_kernel() only until it fails. Pass null on any later iterations. This cleans up the remainder of 2. Signed-off-by: Markus Armbruster Reviewed-by: Li Zhijian Reviewed-by: Juan Quintela Signed-off-by: Juan Quintela Message-ID: <20230928132019.2544702-34-armbru@redhat.com> --- migration/rdma.c | 25 +++++++++++++++++++++---- 1 file changed, 21 insertions(+), 4 deletions(-) diff --git a/migration/rdma.c b/migration/rdma.c index 4074509f06..3fb899f963 100644 --- a/migration/rdma.c +++ b/migration/rdma.c @@ -932,6 +932,7 @@ static int qemu_rdma_broken_ipv6_kernel(struct ibv_context *verbs, Error **errp) */ static int qemu_rdma_resolve_host(RDMAContext *rdma, Error **errp) { + Error *err = NULL; int ret; struct rdma_addrinfo *res; char port_str[16]; @@ -976,7 +977,10 @@ static int qemu_rdma_resolve_host(RDMAContext *rdma, Error **errp) goto err_resolve_get_addr; } + /* Try all addresses, saving the first error in @err */ for (e = res; e != NULL; e = e->ai_next) { + Error **local_errp = err ? NULL : &err; + inet_ntop(e->ai_family, &((struct sockaddr_in *) e->ai_dst_addr)->sin_addr, ip, sizeof ip); trace_qemu_rdma_resolve_host_trying(rdma->host, ip); @@ -985,17 +989,21 @@ static int qemu_rdma_resolve_host(RDMAContext *rdma, Error **errp) RDMA_RESOLVE_TIMEOUT_MS); if (ret >= 0) { if (e->ai_family == AF_INET6) { - ret = qemu_rdma_broken_ipv6_kernel(rdma->cm_id->verbs, errp); + ret = qemu_rdma_broken_ipv6_kernel(rdma->cm_id->verbs, + local_errp); if (ret < 0) { continue; } } + error_free(err); goto route; } } rdma_freeaddrinfo(res); - if (errp && !*errp) { + if (err) { + error_propagate(errp, err); + } else { error_setg(errp, "RDMA ERROR: could not resolve address %s", rdma->host); } @@ -2707,6 +2715,7 @@ err_rdma_source_connect: static int qemu_rdma_dest_init(RDMAContext *rdma, Error **errp) { + Error *err = NULL; int ret, idx; struct rdma_cm_id *listen_id; char ip[40] = "unknown"; @@ -2765,7 +2774,11 @@ static int qemu_rdma_dest_init(RDMAContext *rdma, Error **errp) } goto err_dest_init_bind_addr; } + + /* Try all addresses, saving the first error in @err */ for (e = res; e != NULL; e = e->ai_next) { + Error **local_errp = err ? NULL : &err; + inet_ntop(e->ai_family, &((struct sockaddr_in *) e->ai_dst_addr)->sin_addr, ip, sizeof ip); trace_qemu_rdma_dest_init_trying(rdma->host, ip); @@ -2774,17 +2787,21 @@ static int qemu_rdma_dest_init(RDMAContext *rdma, Error **errp) continue; } if (e->ai_family == AF_INET6) { - ret = qemu_rdma_broken_ipv6_kernel(listen_id->verbs, errp); + ret = qemu_rdma_broken_ipv6_kernel(listen_id->verbs, + local_errp); if (ret < 0) { continue; } } + error_free(err); break; } rdma_freeaddrinfo(res); if (!e) { - if (errp && !*errp) { + if (err) { + error_propagate(errp, err); + } else { error_setg(errp, "RDMA ERROR: Error: could not rdma_bind_addr!"); } goto err_dest_init_bind_addr;