From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dave Jones Subject: suspicious RCU usage (netlink/rhashtable) Date: Tue, 22 Dec 2015 15:45:39 -0500 Message-ID: <20151222204539.GA10690@codemonkey.org.uk> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii To: netdev@vger.kernel.org Return-path: Received: from arcturus.aphlor.org ([188.246.204.175]:58184 "EHLO arcturus.aphlor.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753668AbbLVUpm (ORCPT ); Tue, 22 Dec 2015 15:45:42 -0500 Received: from [209.6.119.210] (helo=wopr.kernelslacker.org) by arcturus.aphlor.org with esmtpsa (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.86) (envelope-from ) id 1aBToS-0000zk-F9 for netdev@vger.kernel.org; Tue, 22 Dec 2015 20:45:40 +0000 Content-Disposition: inline Sender: netdev-owner@vger.kernel.org List-ID: =============================== [ INFO: suspicious RCU usage. ] 4.4.0-rc6-think+ #1 Not tainted ------------------------------- lib/rhashtable.c:522 suspicious rcu_dereference_protected() usage! other info that might help us debug this: rcu_scheduler_active = 1, debug_locks = 0 2 locks held by trinity-c1/3652: #0: (&p->lock){+.+.+.}, at: [] seq_read+0xd7/0x900 #1: (&(&ht->lock)->rlock){+.+...}, at: [] rhashtable_walk_init+0x9d/0x170 stack backtrace: CPU: 0 PID: 3652 Comm: trinity-c1 Not tainted 4.4.0-rc6-think+ #1 ffffffff9af6ac60 000000003fc014d4 ffff8800cff779e0 ffffffff9a548da1 ffff880459b8b700 ffff8800cff77a10 ffffffff9a131068 ffff8800cdd32c48 ffff880464af8000 ffff8800cdd32c58 ffff880464af8160 ffff8800cff77a48 Call Trace: [] dump_stack+0x4e/0x7d [] lockdep_rcu_suspicious+0xf8/0x110 [] rhashtable_walk_init+0x163/0x170 [] netlink_walk_start+0x49/0x90 [] netlink_seq_start+0x40/0x90 [] seq_read+0x1bf/0x900 [] ? seq_lseek+0x1b0/0x1b0 [] ? __might_fault+0xe0/0xf0 [] ? __might_fault+0x87/0xf0 [] ? rw_copy_check_uvector+0x139/0x170 [] proc_reg_read+0x7f/0xc0 [] do_loop_readv_writev+0xe0/0x110 [] ? proc_reg_write+0xc0/0xc0 [] do_readv_writev+0x38b/0x3c0 [] ? proc_reg_write+0xc0/0xc0 [] ? vfs_write+0x260/0x260 [] ? __lock_is_held+0x25/0xd0 [] ? mark_held_locks+0x23/0xc0 [] ? context_tracking_exit.part.5+0x2a/0x50 [] ? trace_hardirqs_on_caller+0x186/0x280 [] ? trace_hardirqs_on+0xd/0x10 [] vfs_readv+0x56/0x70 [] SyS_preadv+0x15d/0x180 [] ? SyS_writev+0x1a0/0x1a0 [] ? trace_hardirqs_on_thunk+0x17/0x19 [] entry_SYSCALL_64_fastpath+0x12/0x6b