From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754208AbaEHJkB (ORCPT ); Thu, 8 May 2014 05:40:01 -0400 Received: from mailout4.samsung.com ([203.254.224.34]:16471 "EHLO mailout4.samsung.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753273AbaEHJj5 convert rfc822-to-8bit (ORCPT ); Thu, 8 May 2014 05:39:57 -0400 X-AuditID: cbfee690-b7fcd6d0000026e0-6c-536b50eb9d6c MIME-version: 1.0 Content-type: text/plain; charset=UTF-8 Content-transfer-encoding: 8BIT Message-id: <1399541860.13268.48.camel@kjgkr> Subject: Re: [BUG] kmemleak on __radix_tree_preload From: Jaegeuk Kim Reply-to: jaegeuk.kim@samsung.com To: Catalin Marinas Cc: Johannes Weiner , "Linux Kernel, Mailing List" , "linux-mm@kvack.org" Date: Thu, 08 May 2014 18:37:40 +0900 In-reply-to: <20140508092646.GA17349@arm.com> References: <1398390340.4283.36.camel@kjgkr> <20140501170610.GB28745@arm.com> <20140501184112.GH23420@cmpxchg.org> <1399431488.13268.29.camel@kjgkr> <20140507113928.GB17253@arm.com> <1399540611.13268.45.camel@kjgkr> <20140508092646.GA17349@arm.com> Organization: Samsung X-Mailer: Evolution 3.2.3-0ubuntu6 X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFrrBIsWRmVeSWpSXmKPExsVy+t8zQ93XAdnBBm3rZSzeL+thtFi9ydfi 8q45bBb31vxndWDxWDNvDaPH4TfvmT02fZrE7vF5k1wASxSXTUpqTmZZapG+XQJXxpX2ycwF zyUrZt6/yNbA2CfSxcjJISFgIrGm6S0zhC0mceHeejYQW0hgGaPEyfmGMDWrZkxg7GLkAoov YpTYM+k/C0iCV0BQ4sfke2A2s4C6xKR5i5ghbBGJs//fsULY2hLLFr5mhmh+xSjx7u9Edohm XYkT63eDFQkLGEssnNrA1MXIwcEG1LB5vwHEEYoSb/ffBSsRASq/0DYFatcURomPx1VAbBYB VYnVvXPBRnIC1VxvgNn1j1Hi5szLYM38AqIShxduh/pSSWJ3eyc7hH2KXeLcTTuIQQIS3yYf YgG5QUJAVmLTAahySYmDK26wTGCUnIXk5VlIXp6F5OVZSF5ewMiyilE0tSC5oDgpvchErzgx t7g0L10vOT93EyMkVifsYLx3wPoQYzLQ+onMUqLJ+cBYzyuJNzQ2M7IwNTE1NjK3NCNNWEmc V+1RUpCQQHpiSWp2ampBalF8UWlOavEhRiYOTqkGxuINTvMz5jGIyn2c8d5yfcHLu90t0Y3L dL+X9XQfNJ+Xu1ZBjfmtdG0od7RGaplgjeyr2eW+mdWFLOmP/00sPFTFfUHlo9av2nlJrKXr A7au4Sk+oe6a46XMM33Pp6vv/uw8EGt7RPHyimxTd68l9zdbvPj59n311Xkrjcz3i+iE59d8 UpU4rcRSnJFoqMVcVJwIAAput+LrAgAA X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFprLKsWRmVeSWpSXmKPExsVy+t9jAd3XAdnBBq1rJCzeL+thtFi9ydfi 8q45bBb31vxndWDxWDNvDaPH4TfvmT02fZrE7vF5k1wAS1QDo01GamJKapFCal5yfkpmXrqt kndwvHO8qZmBoa6hpYW5kkJeYm6qrZKLT4CuW2YO0EolhbLEnFKgUEBicbGSvh2mCaEhbroW MI0Rur4hQXA9RgZoIGEdY0bD1sNMBaclK+5PesLawPhJuIuRk0NCwERi1YwJjBC2mMSFe+vZ uhi5OIQEFjFK7Jn0nwUkwSsgKPFj8j0gm4ODWUBe4silbJAws4C6xKR5i5gh6l8xSrz7O5Ed ol5X4sT63awgtrCAscTCqQ1MIL1sAtoSm/cbgISFBBQl3u6/C1YiAlR+oW0KC8TMKYwSH4+r gNgsAqoSq3vngo3kBKq53vAaatc/RombMy+DNfMLiEocXridGeIBJYnd7Z3sExiFZiE5exbC 2bOQnL2AkXkVo2hqQXJBcVJ6rqFecWJucWleul5yfu4mRnBkP5PawbiyweIQowAHoxIPb4Zz VrAQa2JZcWXuIUYJDmYlEV4e/+xgId6UxMqq1KL8+KLSnNTiQ4zJQJdPZJYSTc4HJp28knhD YxMzI0sjMwsjE3Nz0oSVxHkPtFoHCgmkJ5akZqemFqQWwWxh4uCUamBMXfiJv0Th/H3zTt+g nVVPuA+7Tn/l96zC6O3/1JLI59OSWHOO+Xe+3NVe2RIdN4Ntd4Mgq3OpjgrnLOYlD55+eHw9 R27+JA15ifK991hP2W1b41vNlyzBH9Vv/7FnanBbeJFXG+tOtqYXsT5zN2pKWM78I76sr0b2 YfbRzV8at1veW9jyyEGJpTgj0VCLuag4EQBcD0lJMAMAAA== DLP-Filter: Pass X-MTR: 20000000000000000@CPGS X-CFilter-Loop: Reflected Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 2014-05-08 (목), 10:26 +0100, Catalin Marinas: > On Thu, May 08, 2014 at 06:16:51PM +0900, Jaegeuk Kim wrote: > > 2014-05-07 (수), 12:39 +0100, Catalin Marinas: > > > On Wed, May 07, 2014 at 03:58:08AM +0100, Jaegeuk Kim wrote: > > > > unreferenced object 0xffff880004226da0 (size 576): > > > > comm "fsstress", pid 14590, jiffies 4295191259 (age 706.308s) > > > > hex dump (first 32 bytes): > > > > 01 00 00 00 81 ff ff ff 00 00 00 00 00 00 00 00 ................ > > > > 50 89 34 81 ff ff ff ff b8 6d 22 04 00 88 ff ff P.4......m"..... > > > > backtrace: > > > > [] kmemleak_update_trace+0x58/0x80 > > > > [] radix_tree_node_alloc+0x77/0xa0 > > > > [] __radix_tree_create+0x1d8/0x230 > > > > [] __add_to_page_cache_locked+0x9c/0x1b0 > > > > [] add_to_page_cache_lru+0x28/0x80 > > > > [] grab_cache_page_write_begin+0x98/0xf0 > > > > [] f2fs_write_begin+0xb4/0x3c0 [f2fs] > > > > [] generic_perform_write+0xc7/0x1c0 > > > > [] __generic_file_aio_write+0x1cd/0x3f0 > > > > [] generic_file_aio_write+0x5e/0xe0 > > > > [] do_sync_write+0x5a/0x90 > > > > [] vfs_write+0xc2/0x1d0 > > > > [] SyS_write+0x4f/0xb0 > > > > [] system_call_fastpath+0x16/0x1b > > > > [] 0xffffffffffffffff > > > > > > OK, it shows that the allocation happens via add_to_page_cache_locked() > > > and I guess it's page_cache_tree_insert() which calls > > > __radix_tree_create() (the latter reusing the preloaded node). I'm not > > > familiar enough to this code (radix-tree.c and filemap.c) to tell where > > > the node should have been freed, who keeps track of it. > > > > > > At a quick look at the hex dump (assuming that the above leak is struct > > > radix_tree_node): > > > > > > .path = 1 > > > .count = -0x7f (or 0xffffff81 as unsigned int) > > > union { > > > { > > > .parent = NULL > > > .private_data = 0xffffffff81348950 > > > } > > > { > > > .rcu_head.next = NULL > > > .rcu_head.func = 0xffffffff81348950 > > > } > > > } > > > > > > The count is a bit suspicious. > > > > > > From the union, it looks most likely like rcu_head information. Is > > > radix_tree_node_rcu_free() function at the above rcu_head.func? > > Thanks for the config. Could you please confirm that 0xffffffff81348950 > address corresponds to the radix_tree_node_rcu_free() function in your > System.map (or something else)? Yap, the address is matched to radix_tree_node_rcu_free(). Thanks, > > > > Also, if you run echo scan > /sys/kernel/debug/kmemleak a few times, do > > > any of the above leaks disappear (in case the above are some transient > > > rcu freeing reports; normally this shouldn't happen as the objects are > > > still referred but I'll look at the relevant code once I have your > > > .config). > > > > Once I run the echo, the leaks are still remained. > > OK, so they aren't just transient. > > Thanks. > -- Jaegeuk Kim Samsung