From patchwork Fri Jan 24 09:32:38 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 232891 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=-9.8 required=3.0 tests=DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH, MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham 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 1F204C2D0DB for ; Fri, 24 Jan 2020 11:33:15 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E103420704 for ; Fri, 24 Jan 2020 11:33:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1579865595; bh=N1lZJQd5ITxkNjiZcGkSA8GurHA4toeYev0oUfY+YSo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=ehghUTCvQa8EBK3j12wk6fZD46bSa8wX2u5Ntrp/hnlo8Vj+b7cY367vkuco6PqCF XCITKbqZwwlxd2leG4FUvGMcUlmQRUAQoMY2NYo7nHwt8vwbdIZjt6sddAawLqaVGq As+IK6m+yPe0jcECzqssfIRdf7OChxzkHvJPQvSQ= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2404544AbgAXLdN (ORCPT ); Fri, 24 Jan 2020 06:33:13 -0500 Received: from mail.kernel.org ([198.145.29.99]:52588 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2404554AbgAXLdM (ORCPT ); Fri, 24 Jan 2020 06:33:12 -0500 Received: from localhost (ip-213-127-102-57.ip.prioritytelecom.net [213.127.102.57]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 9D3FE20704; Fri, 24 Jan 2020 11:33:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1579865592; bh=N1lZJQd5ITxkNjiZcGkSA8GurHA4toeYev0oUfY+YSo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=OAn8DQERRXVG7kWkk4jHxhj7pgckyo8jdKakRZR3aF7MtPnkENqRinOac8s+9Rx01 zDRBLc1BrGwc0Z4JlqsSqEsqiRBmzUbazZBKO64QGAXKVpYryrTg/sPeAIAY4MDDzy A5IvE8FGW0HssQ9aqptIl1UJwuzHQrQDWYTp+tOo= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, David Howells , Sasha Levin Subject: [PATCH 4.19 588/639] rxrpc: Fix trace-after-put looking at the put connection record Date: Fri, 24 Jan 2020 10:32:38 +0100 Message-Id: <20200124093203.109044279@linuxfoundation.org> X-Mailer: git-send-email 2.25.0 In-Reply-To: <20200124093047.008739095@linuxfoundation.org> References: <20200124093047.008739095@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: David Howells [ Upstream commit 4c1295dccc0afe0905b6ca4c62ade7f2406f2cfb ] rxrpc_put_*conn() calls trace_rxrpc_conn() after they have done the decrement of the refcount - which looks at the debug_id in the connection record. But unless the refcount was reduced to zero, we no longer have the right to look in the record and, indeed, it may be deleted by some other thread. Fix this by getting the debug_id out before decrementing the refcount and then passing that into the tracepoint. Fixes: 363deeab6d0f ("rxrpc: Add connection tracepoint and client conn state tracepoint") Signed-off-by: David Howells Signed-off-by: Sasha Levin --- include/trace/events/rxrpc.h | 6 +++--- net/rxrpc/call_accept.c | 2 +- net/rxrpc/conn_client.c | 6 ++++-- net/rxrpc/conn_object.c | 13 +++++++------ net/rxrpc/conn_service.c | 2 +- 5 files changed, 16 insertions(+), 13 deletions(-) diff --git a/include/trace/events/rxrpc.h b/include/trace/events/rxrpc.h index a08916eb76152..0924119bcfa40 100644 --- a/include/trace/events/rxrpc.h +++ b/include/trace/events/rxrpc.h @@ -554,10 +554,10 @@ TRACE_EVENT(rxrpc_peer, ); TRACE_EVENT(rxrpc_conn, - TP_PROTO(struct rxrpc_connection *conn, enum rxrpc_conn_trace op, + TP_PROTO(unsigned int conn_debug_id, enum rxrpc_conn_trace op, int usage, const void *where), - TP_ARGS(conn, op, usage, where), + TP_ARGS(conn_debug_id, op, usage, where), TP_STRUCT__entry( __field(unsigned int, conn ) @@ -567,7 +567,7 @@ TRACE_EVENT(rxrpc_conn, ), TP_fast_assign( - __entry->conn = conn->debug_id; + __entry->conn = conn_debug_id; __entry->op = op; __entry->usage = usage; __entry->where = where; diff --git a/net/rxrpc/call_accept.c b/net/rxrpc/call_accept.c index 8079aacaecace..c5566bc4aaca3 100644 --- a/net/rxrpc/call_accept.c +++ b/net/rxrpc/call_accept.c @@ -88,7 +88,7 @@ static int rxrpc_service_prealloc_one(struct rxrpc_sock *rx, smp_store_release(&b->conn_backlog_head, (head + 1) & (size - 1)); - trace_rxrpc_conn(conn, rxrpc_conn_new_service, + trace_rxrpc_conn(conn->debug_id, rxrpc_conn_new_service, atomic_read(&conn->usage), here); } diff --git a/net/rxrpc/conn_client.c b/net/rxrpc/conn_client.c index 3dbb126e60608..38d5485320242 100644 --- a/net/rxrpc/conn_client.c +++ b/net/rxrpc/conn_client.c @@ -217,7 +217,8 @@ rxrpc_alloc_client_connection(struct rxrpc_conn_parameters *cp, gfp_t gfp) rxrpc_get_local(conn->params.local); key_get(conn->params.key); - trace_rxrpc_conn(conn, rxrpc_conn_new_client, atomic_read(&conn->usage), + trace_rxrpc_conn(conn->debug_id, rxrpc_conn_new_client, + atomic_read(&conn->usage), __builtin_return_address(0)); trace_rxrpc_client(conn, -1, rxrpc_client_alloc); _leave(" = %p", conn); @@ -989,11 +990,12 @@ rxrpc_put_one_client_conn(struct rxrpc_connection *conn) void rxrpc_put_client_conn(struct rxrpc_connection *conn) { const void *here = __builtin_return_address(0); + unsigned int debug_id = conn->debug_id; int n; do { n = atomic_dec_return(&conn->usage); - trace_rxrpc_conn(conn, rxrpc_conn_put_client, n, here); + trace_rxrpc_conn(debug_id, rxrpc_conn_put_client, n, here); if (n > 0) return; ASSERTCMP(n, >=, 0); diff --git a/net/rxrpc/conn_object.c b/net/rxrpc/conn_object.c index 004a6eb529bc1..f338efd2880aa 100644 --- a/net/rxrpc/conn_object.c +++ b/net/rxrpc/conn_object.c @@ -272,7 +272,7 @@ bool rxrpc_queue_conn(struct rxrpc_connection *conn) if (n == 0) return false; if (rxrpc_queue_work(&conn->processor)) - trace_rxrpc_conn(conn, rxrpc_conn_queued, n + 1, here); + trace_rxrpc_conn(conn->debug_id, rxrpc_conn_queued, n + 1, here); else rxrpc_put_connection(conn); return true; @@ -287,7 +287,7 @@ void rxrpc_see_connection(struct rxrpc_connection *conn) if (conn) { int n = atomic_read(&conn->usage); - trace_rxrpc_conn(conn, rxrpc_conn_seen, n, here); + trace_rxrpc_conn(conn->debug_id, rxrpc_conn_seen, n, here); } } @@ -299,7 +299,7 @@ void rxrpc_get_connection(struct rxrpc_connection *conn) const void *here = __builtin_return_address(0); int n = atomic_inc_return(&conn->usage); - trace_rxrpc_conn(conn, rxrpc_conn_got, n, here); + trace_rxrpc_conn(conn->debug_id, rxrpc_conn_got, n, here); } /* @@ -313,7 +313,7 @@ rxrpc_get_connection_maybe(struct rxrpc_connection *conn) if (conn) { int n = atomic_fetch_add_unless(&conn->usage, 1, 0); if (n > 0) - trace_rxrpc_conn(conn, rxrpc_conn_got, n + 1, here); + trace_rxrpc_conn(conn->debug_id, rxrpc_conn_got, n + 1, here); else conn = NULL; } @@ -336,10 +336,11 @@ static void rxrpc_set_service_reap_timer(struct rxrpc_net *rxnet, void rxrpc_put_service_conn(struct rxrpc_connection *conn) { const void *here = __builtin_return_address(0); + unsigned int debug_id = conn->debug_id; int n; n = atomic_dec_return(&conn->usage); - trace_rxrpc_conn(conn, rxrpc_conn_put_service, n, here); + trace_rxrpc_conn(debug_id, rxrpc_conn_put_service, n, here); ASSERTCMP(n, >=, 0); if (n == 1) rxrpc_set_service_reap_timer(conn->params.local->rxnet, @@ -423,7 +424,7 @@ void rxrpc_service_connection_reaper(struct work_struct *work) */ if (atomic_cmpxchg(&conn->usage, 1, 0) != 1) continue; - trace_rxrpc_conn(conn, rxrpc_conn_reap_service, 0, NULL); + trace_rxrpc_conn(conn->debug_id, rxrpc_conn_reap_service, 0, NULL); if (rxrpc_conn_is_client(conn)) BUG(); diff --git a/net/rxrpc/conn_service.c b/net/rxrpc/conn_service.c index 80773a50c7551..6da7c4bf15e88 100644 --- a/net/rxrpc/conn_service.c +++ b/net/rxrpc/conn_service.c @@ -138,7 +138,7 @@ struct rxrpc_connection *rxrpc_prealloc_service_connection(struct rxrpc_net *rxn list_add_tail(&conn->proc_link, &rxnet->conn_proc_list); write_unlock(&rxnet->conn_lock); - trace_rxrpc_conn(conn, rxrpc_conn_new_service, + trace_rxrpc_conn(conn->debug_id, rxrpc_conn_new_service, atomic_read(&conn->usage), __builtin_return_address(0)); }