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=-10.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable 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 CF74AC33CAF for ; Thu, 16 Jan 2020 18:38:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 9DF6E2073A for ; Thu, 16 Jan 2020 18:38:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1579199914; bh=zC4D4MYBaF72dGuCGXktAmFfdxLO8JRLMOOUy13Gxfc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=jKZPlQ5NaIRrqGME8p8Yd/R0VeFfLaLmnINlCu9w30pRiWcrMpnSd2M69984Qkl7E 2XTGkMweV+Y6KOczXMf1xbed2XxsrLCrUCuRf7SDExYlVZ0OhTr/TLULpZwh/CXtkL 3a0i1weLlfLau8ZP46gPwJrydTeLM5OUtjAN8h+s= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2436871AbgAPSid (ORCPT ); Thu, 16 Jan 2020 13:38:33 -0500 Received: from mail.kernel.org ([198.145.29.99]:55262 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2390482AbgAPRM2 (ORCPT ); Thu, 16 Jan 2020 12:12:28 -0500 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id E87C324696; Thu, 16 Jan 2020 17:12:26 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1579194747; bh=zC4D4MYBaF72dGuCGXktAmFfdxLO8JRLMOOUy13Gxfc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=zy1tBCr/sw95Cj9boHnC8dpeHEKKB47+3Bfu69d4pYBL5w6zN1IkFXoDFo91G7WvH sBsxFmzFW096lXF4IxoBJR904GsG1UdE3oJTmTN1FNwvBK3B7KXJGGwMe+8qbR0fl7 MHdjtD36VPmG7+NV4QptEtKpL+gaLhufuv68wIDQ= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: David Howells , Sasha Levin , linux-afs@lists.infradead.org, netdev@vger.kernel.org Subject: [PATCH AUTOSEL 4.19 576/671] rxrpc: Fix trace-after-put looking at the put connection record Date: Thu, 16 Jan 2020 12:03:34 -0500 Message-Id: <20200116170509.12787-313-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20200116170509.12787-1-sashal@kernel.org> References: <20200116170509.12787-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@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 a08916eb7615..0924119bcfa4 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 8079aacaecac..c5566bc4aaca 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 3dbb126e6060..38d548532024 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 004a6eb529bc..f338efd2880a 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 80773a50c755..6da7c4bf15e8 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)); } -- 2.20.1