From mboxrd@z Thu Jan 1 00:00:00 1970 Content-Type: multipart/mixed; boundary="===============4957946778164518597==" MIME-Version: 1.0 From: Mathieu Desnoyers To: lkp@lists.01.org Subject: Re: [srcu] a365bb5f6e: leaking_addresses.proc.___srcu_struct_ptrs. Date: Mon, 08 Apr 2019 13:25:49 -0400 Message-ID: <1930819602.1467.1554744349263.JavaMail.zimbra@efficios.com> In-Reply-To: <20190408171041.GQ14111@linux.ibm.com> List-Id: --===============4957946778164518597== Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable ----- On Apr 8, 2019, at 1:10 PM, paulmck paulmck(a)linux.ibm.com wrote: > On Mon, Apr 08, 2019 at 01:06:56PM -0400, Mathieu Desnoyers wrote: >> ----- On Apr 8, 2019, at 11:21 AM, paulmck paulmck(a)linux.ibm.com wrote: >> = >> > On Mon, Apr 08, 2019 at 10:57:50PM +0800, Rong Chen wrote: >> >> On Mon, Apr 08, 2019 at 07:30:37AM -0700, Paul E. McKenney wrote: >> >> > On Mon, Apr 08, 2019 at 09:56:10PM +0800, kernel test robot wrote: >> >> > > FYI, we noticed the following commit (built with gcc-7): >> >> > > = >> >> > > commit: a365bb5f6eafb220a1448674054b05c250829313 ("srcu: Allocate= per-CPU data >> >> > > for DEFINE_SRCU() in modules") >> >> > > https://git.kernel.org/cgit/linux/kernel/git/paulmck/linux-rcu.git >> >> > > tmp.2019.04.07a >> >> > > = >> >> > > in testcase: leaking_addresses >> >> > > with following parameters: >> >> > > = >> >> > > = >> >> > > = >> >> > > = >> >> > > on test machine: qemu-system-x86_64 -enable-kvm -cpu SandyBridge = -smp 2 -m 2G >> >> > > = >> >> > > caused below changes (please refer to attached dmesg/kmsg for ent= ire >> >> > > log/backtrace): >> >> > > = >> >> > > = >> >> > > +-------------------------------------------------+------------+-= -----------+ >> >> > > | | a44a55abae | = a365bb5f6e | >> >> > > +-------------------------------------------------+------------+-= -----------+ >> >> > > | boot_successes | 0 | = 3 | >> >> > > | boot_failures | 4 | = 6 | >> >> > > | BUG:kernel_reboot-without-warning_in_test_stage | 4 | = 6 | >> >> > > | leaking_addresses.proc.___srcu_struct_ptrs. | 0 | = 6 | >> >> > > +-------------------------------------------------+------------+-= -----------+ >> >> > = >> >> > Please help me out here. Without this commit, the kernel never suc= ceeds >> >> > in booting, but with it the kernel sometimes succeeds in booting? = Or am >> >> > I misinterpreting the above table? >> >> > = >> >> > Thanx, Paul >> >> = >> >> Hi Paul, >> >> = >> >> The message "kernel_reboot-without-warning_in_test_stage" is from 0da= y, >> >> leaking addresses generated many dmesgs, so 0day thought some booting= s may >> >> failed. >> > = >> [...] >> >> > = >> >> > > [1 .rodata.cst16.POLY] 0xffffffffc0498360 >> >> > > [1 .rodata.cst32.byteshift_table] 0xffffffffc03f50f0 >> >> > > [19 __bug_table] 0xffffffffc02be184 >> >> > > [2 __tracepoints_ptrs] 0xffffffffc02f1cd0 >> >> > > [15 .smp_locks] 0xffffffffc042b2cc >> >> > > [1 .rodata.cst16.enc] 0xffffffffc0498420 >> >> > > [11 __ksymtab_gpl] 0xffffffffc042b028 >> >> > > [8 __ex_table] 0xffffffffc04f13f4 >> >> > > [1 .init.rodata] 0xffffffffc0316000 >> >> > > [36 .note.gnu.build-id] 0xffffffffc03ed000 >> >> > > [1 .rodata.cst16.dec] 0xffffffffc0498410 >> >> > > [16 .parainstructions] 0xffffffffc03ed940 >> >> > > [8 .text..refcount] 0xffffffffc04e2aaa >> >> > > [36 .gnu.linkonce.this_module] 0xffffffffc03f12c0 >> >> > > [2 __bpf_raw_tp_map] 0xffffffffc03054a0 >> >> > > [30 .orc_unwind_ip] 0xffffffffc03ee9f9 >> >> > > [8 .altinstr_replacement] 0xffffffffc0497372 >> >> > > [26 .rodata.str1.8] 0xffffffffc03ed1f0 >> >> > > [11 __verbose] 0xffffffffc05c9398 >> >> > > [1 .rodata.cst16.TWOONE] 0xffffffffc0498380 >> >> > > [1 uevent] KEY=3D402000000 3803078f800d001 feffffdfffefffff fffff= ffffffffffe >> >> > > [1 .rodata.cst16.ONE] 0xffffffffc04983e0 >> >> > > [8 .altinstructions] 0xffffffffc0498430 >> >> > > [36 modules] crct10dif_pclmul 16384 1 - Live 0xffffffffc03f4000 >> >> > > [1 ___srcu_struct_ptrs] 0xffffffffc03840d0 >> >> > > = >> = >> This list of "leaked" memory seems to include the __tracepoint_ptrs >> as well. So at least you seem to have the same behavior as the tracepoint >> code, which was your source of inspiration for this implementation, >> which is a good start. >> = >> So the remaining question is: is this memory allocated for module sectio= ns >> really leaked for each module, or is it an issue with memory allocation >> tracking ? > = > Thank you, Mathieu! > = > Also, is there some way to put this read-only (OK, relocated-only) > memory in with the module .text segment? ;-) Theoretically, there should be! But I have no clue on how to do it. Thanks, Mathieu -- = Mathieu Desnoyers EfficiOS Inc. http://www.efficios.com --===============4957946778164518597==-- 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=-6.1 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING,SPF_PASS 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 55D1EC10F13 for ; Mon, 8 Apr 2019 17:25:54 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 182A8213F2 for ; Mon, 8 Apr 2019 17:25:54 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=efficios.com header.i=@efficios.com header.b="lu1AwZxY" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729083AbfDHRZx (ORCPT ); Mon, 8 Apr 2019 13:25:53 -0400 Received: from mail.efficios.com ([167.114.142.138]:52004 "EHLO mail.efficios.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726880AbfDHRZv (ORCPT ); Mon, 8 Apr 2019 13:25:51 -0400 Received: from localhost (ip6-localhost [IPv6:::1]) by mail.efficios.com (Postfix) with ESMTP id BFA7B1D3C4C; Mon, 8 Apr 2019 13:25:49 -0400 (EDT) Received: from mail.efficios.com ([IPv6:::1]) by localhost (mail02.efficios.com [IPv6:::1]) (amavisd-new, port 10032) with ESMTP id oZ-29zCel_oS; Mon, 8 Apr 2019 13:25:49 -0400 (EDT) Received: from localhost (ip6-localhost [IPv6:::1]) by mail.efficios.com (Postfix) with ESMTP id 6BF291D3C45; Mon, 8 Apr 2019 13:25:49 -0400 (EDT) DKIM-Filter: OpenDKIM Filter v2.10.3 mail.efficios.com 6BF291D3C45 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=efficios.com; s=default; t=1554744349; bh=jh26Zvv8udxRgGtlQh6FmH4n1moq3HDOeT3f96ju2p0=; h=Date:From:To:Message-ID:MIME-Version; b=lu1AwZxY1DOhL2vov/hwp2ydhntaGuabArCxiqZifzmgdEKtyh09NxmH0VV2yhWXx KRjqU5fh4y+jP7iptpdZTEsXO4qO7DpujwzqhiJZlu4JsH2+mrR0kg2YDqnWs9ckA9 LVLqoflNPlMfleX+nR4y5TQ2AIRzvg6DNMDSYvKoFoHk9n97dcq2MaXPt0kaDVygKI 4QyIVfmSkfRba1tus75mCXeNFl2DvGFdekor6ki7djBkp5yYBPDLaqfHXniYoWxv1I Ljz5yebzKT2V33JXE7IPXoGYx82Q0Pm/1RqCdR+PacXbBOfhDf90tcDbaciMSLBeJY FtQ0KCftky/0A== X-Virus-Scanned: amavisd-new at efficios.com Received: from mail.efficios.com ([IPv6:::1]) by localhost (mail02.efficios.com [IPv6:::1]) (amavisd-new, port 10026) with ESMTP id LKT4lmb4o6Yo; Mon, 8 Apr 2019 13:25:49 -0400 (EDT) Received: from mail02.efficios.com (mail02.efficios.com [167.114.142.138]) by mail.efficios.com (Postfix) with ESMTP id 4CB351D3C34; Mon, 8 Apr 2019 13:25:49 -0400 (EDT) Date: Mon, 8 Apr 2019 13:25:49 -0400 (EDT) From: Mathieu Desnoyers To: paulmck Cc: Rong Chen , linux-kernel , LKP , "Joel Fernandes, Google" Message-ID: <1930819602.1467.1554744349263.JavaMail.zimbra@efficios.com> In-Reply-To: <20190408171041.GQ14111@linux.ibm.com> References: <20190408135610.GN11264@shao2-debian> <20190408143037.GL14111@linux.ibm.com> <20190408145750.GO11264@shao2-debian> <20190408152112.GM14111@linux.ibm.com> <118257214.1376.1554743216233.JavaMail.zimbra@efficios.com> <20190408171041.GQ14111@linux.ibm.com> Subject: Re: [srcu] a365bb5f6e: leaking_addresses.proc.___srcu_struct_ptrs. MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit X-Originating-IP: [167.114.142.138] X-Mailer: Zimbra 8.8.12_GA_3794 (ZimbraWebClient - FF66 (Linux)/8.8.12_GA_3794) Thread-Topic: a365bb5f6e: leaking_addresses.proc.___srcu_struct_ptrs. Thread-Index: SF2mnaFEDzZ2dPi6dfzsO1XZYVq0SQ== Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org ----- On Apr 8, 2019, at 1:10 PM, paulmck paulmck@linux.ibm.com wrote: > On Mon, Apr 08, 2019 at 01:06:56PM -0400, Mathieu Desnoyers wrote: >> ----- On Apr 8, 2019, at 11:21 AM, paulmck paulmck@linux.ibm.com wrote: >> >> > On Mon, Apr 08, 2019 at 10:57:50PM +0800, Rong Chen wrote: >> >> On Mon, Apr 08, 2019 at 07:30:37AM -0700, Paul E. McKenney wrote: >> >> > On Mon, Apr 08, 2019 at 09:56:10PM +0800, kernel test robot wrote: >> >> > > FYI, we noticed the following commit (built with gcc-7): >> >> > > >> >> > > commit: a365bb5f6eafb220a1448674054b05c250829313 ("srcu: Allocate per-CPU data >> >> > > for DEFINE_SRCU() in modules") >> >> > > https://git.kernel.org/cgit/linux/kernel/git/paulmck/linux-rcu.git >> >> > > tmp.2019.04.07a >> >> > > >> >> > > in testcase: leaking_addresses >> >> > > with following parameters: >> >> > > >> >> > > >> >> > > >> >> > > >> >> > > on test machine: qemu-system-x86_64 -enable-kvm -cpu SandyBridge -smp 2 -m 2G >> >> > > >> >> > > caused below changes (please refer to attached dmesg/kmsg for entire >> >> > > log/backtrace): >> >> > > >> >> > > >> >> > > +-------------------------------------------------+------------+------------+ >> >> > > | | a44a55abae | a365bb5f6e | >> >> > > +-------------------------------------------------+------------+------------+ >> >> > > | boot_successes | 0 | 3 | >> >> > > | boot_failures | 4 | 6 | >> >> > > | BUG:kernel_reboot-without-warning_in_test_stage | 4 | 6 | >> >> > > | leaking_addresses.proc.___srcu_struct_ptrs. | 0 | 6 | >> >> > > +-------------------------------------------------+------------+------------+ >> >> > >> >> > Please help me out here. Without this commit, the kernel never succeeds >> >> > in booting, but with it the kernel sometimes succeeds in booting? Or am >> >> > I misinterpreting the above table? >> >> > >> >> > Thanx, Paul >> >> >> >> Hi Paul, >> >> >> >> The message "kernel_reboot-without-warning_in_test_stage" is from 0day, >> >> leaking addresses generated many dmesgs, so 0day thought some bootings may >> >> failed. >> > >> [...] >> >> > >> >> > > [1 .rodata.cst16.POLY] 0xffffffffc0498360 >> >> > > [1 .rodata.cst32.byteshift_table] 0xffffffffc03f50f0 >> >> > > [19 __bug_table] 0xffffffffc02be184 >> >> > > [2 __tracepoints_ptrs] 0xffffffffc02f1cd0 >> >> > > [15 .smp_locks] 0xffffffffc042b2cc >> >> > > [1 .rodata.cst16.enc] 0xffffffffc0498420 >> >> > > [11 __ksymtab_gpl] 0xffffffffc042b028 >> >> > > [8 __ex_table] 0xffffffffc04f13f4 >> >> > > [1 .init.rodata] 0xffffffffc0316000 >> >> > > [36 .note.gnu.build-id] 0xffffffffc03ed000 >> >> > > [1 .rodata.cst16.dec] 0xffffffffc0498410 >> >> > > [16 .parainstructions] 0xffffffffc03ed940 >> >> > > [8 .text..refcount] 0xffffffffc04e2aaa >> >> > > [36 .gnu.linkonce.this_module] 0xffffffffc03f12c0 >> >> > > [2 __bpf_raw_tp_map] 0xffffffffc03054a0 >> >> > > [30 .orc_unwind_ip] 0xffffffffc03ee9f9 >> >> > > [8 .altinstr_replacement] 0xffffffffc0497372 >> >> > > [26 .rodata.str1.8] 0xffffffffc03ed1f0 >> >> > > [11 __verbose] 0xffffffffc05c9398 >> >> > > [1 .rodata.cst16.TWOONE] 0xffffffffc0498380 >> >> > > [1 uevent] KEY=402000000 3803078f800d001 feffffdfffefffff fffffffffffffffe >> >> > > [1 .rodata.cst16.ONE] 0xffffffffc04983e0 >> >> > > [8 .altinstructions] 0xffffffffc0498430 >> >> > > [36 modules] crct10dif_pclmul 16384 1 - Live 0xffffffffc03f4000 >> >> > > [1 ___srcu_struct_ptrs] 0xffffffffc03840d0 >> >> > > >> >> This list of "leaked" memory seems to include the __tracepoint_ptrs >> as well. So at least you seem to have the same behavior as the tracepoint >> code, which was your source of inspiration for this implementation, >> which is a good start. >> >> So the remaining question is: is this memory allocated for module sections >> really leaked for each module, or is it an issue with memory allocation >> tracking ? > > Thank you, Mathieu! > > Also, is there some way to put this read-only (OK, relocated-only) > memory in with the module .text segment? ;-) Theoretically, there should be! But I have no clue on how to do it. Thanks, Mathieu -- Mathieu Desnoyers EfficiOS Inc. http://www.efficios.com