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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 6DC25C678D5 for ; Wed, 8 Mar 2023 13:15:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230379AbjCHNPa (ORCPT ); Wed, 8 Mar 2023 08:15:30 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60684 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230365AbjCHNPI (ORCPT ); Wed, 8 Mar 2023 08:15:08 -0500 Received: from domac.alu.hr (domac.alu.unizg.hr [IPv6:2001:b68:2:2800::3]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E07C6D162D; Wed, 8 Mar 2023 05:11:52 -0800 (PST) Received: from localhost (localhost [127.0.0.1]) by domac.alu.hr (Postfix) with ESMTP id 1D117604F3; Wed, 8 Mar 2023 14:11:47 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=alu.unizg.hr; s=mail; t=1678281107; bh=9YOSH9fsyQWwKgc7rYyqDCSYLUM86K9yyDYVc5F0/Vc=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=U7VOEF/wK5DEXiApc/3iVem4s5vxgIyWW+BNudaqs37JsDK/w/MCLj7mGBPK/LNEp HGcoUchtNEX5SHW/EN1hGIHKjfyitbGR72Sq+/7Ah20s8VYBOVOY1zlz9kfPTmctO1 twQlKkSfiUoME6+17LxQBjEJNS7WCmBYjo+HnHJelUtU/PmSOAg+6X7WjpY/HFwGhq 00ETNKpDPjLlz60DnmetHlsDeKZwCxEOWIBQAaJ8Cd37rPhCqXdHN4+rZN3sEMdPFl kl8jkU3bzj3x3w6khSNzeFQbwuzIYu+6qqiaz/qVbrV3o6NKMRjQ66UQTbtjiIy3O4 eC8dW3U/zaOQA== X-Virus-Scanned: Debian amavisd-new at domac.alu.hr Received: from domac.alu.hr ([127.0.0.1]) by localhost (domac.alu.hr [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id SeE9Gx7tn6T1; Wed, 8 Mar 2023 14:11:44 +0100 (CET) Received: from [193.198.186.200] (pc-mtodorov.slava.alu.hr [193.198.186.200]) by domac.alu.hr (Postfix) with ESMTPSA id C6F4D604F5; Wed, 8 Mar 2023 14:11:43 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=alu.unizg.hr; s=mail; t=1678281104; bh=9YOSH9fsyQWwKgc7rYyqDCSYLUM86K9yyDYVc5F0/Vc=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=g3TkGpUQlkwUumtS5q6MmMBvvm9Qy4TdoDMIkg67yvd+dYj79RKFVWM5G1+jPMShW f+ZgKBWBiXj2gtnAjacN5r8VD4EWoxxRHzeNGkJuYWhyae5OWHAbbT3HGEULRADsnW HFe7OnpIZ0S3gNfEf1TTwfQnie7wq/wTq3GTnHHpBZ7f1Ff1BiXjw+Tf4UJMX+s5yS lWwY423Gw0iqjrk3dlPiWHT9KfxDce/xKcP7z3cKv45KzZK2XzN4OK2VvmlIx1HXqU HjyqeOmwa48wWFE686RY9gHpJD04ZqVZwQ9R/J5HgCdC7kwr1qOD9zuksaYasNXu7c R1lELc85gDnlA== Message-ID: <93d606c4-fe48-757b-28fa-4786ed3302c3@alu.unizg.hr> Date: Wed, 8 Mar 2023 14:11:39 +0100 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.8.0 Subject: Re: INFO: REPRODUCED: memory leak in gpio device in 6.2-rc6 To: Andy Shevchenko Cc: Bartosz Golaszewski , linux-gpio@vger.kernel.org, Linus Walleij , linux-kernel@vger.kernel.org, Thorsten Leemhuis References: <3d96e50b-ed17-9bf5-149b-8a50c7b4cca2@alu.unizg.hr> <4b001ce6-b35d-3ad1-b757-f5f6baca7b51@alu.unizg.hr> <7856e5a8-d84e-4f41-721b-80b6fc413919@alu.unizg.hr> <2373a9ab-1c38-35fd-e961-9a172f8ce622@alu.unizg.hr> Content-Language: en-US, hr From: Mirsad Todorovac In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-gpio@vger.kernel.org On 2/28/23 00:13, Andy Shevchenko wrote: Hi, Andy! >> The logs are extensive if you are willing to skim over them, but I believe the interesting >> part is this: > > I'm not sure I understand where the problem is. > >> [ 4830.764748] kobject: 'gpio-sim' (000000005b8d0726): kobject_release, parent 000000007425b13f (delayed 750) >> [ 4833.908238] kobject: 'gpio-sim' (000000005b8d0726): kobject_cleanup, parent 000000007425b13f >> [ 4833.908244] kobject: 'gpio-sim' (000000005b8d0726): auto cleanup kobject_del >> [ 4833.908245] kobject: 'gpio-sim' (000000005b8d0726): auto cleanup 'remove' event >> [ 4833.908247] kobject: 'gpio-sim' (000000005b8d0726): kobject_uevent_env >> [ 4833.908273] kobject: 'gpio-sim' (000000005b8d0726): fill_kobj_path: path = '/bus/platform/drivers/gpio-sim' >> [ 4833.908311] kobject: 'gpio-sim' (000000005b8d0726): calling ktype release >> [ 4833.908315] kobject: 'gpio-sim': free name >> [ 4834.932303] kobject: 'gpio_sim' (0000000096ea0bb1): kobject_release, parent 0000000093357d30 (delayed 250) >> [ 4835.952388] kobject: 'gpio_sim' (0000000096ea0bb1): kobject_cleanup, parent 0000000093357d30 >> [ 4835.952413] kobject: 'gpio_sim' (0000000096ea0bb1): auto cleanup kobject_del >> [ 4835.952415] kobject: 'gpio_sim' (0000000096ea0bb1): auto cleanup 'remove' event >> [ 4835.952416] kobject: 'gpio_sim' (0000000096ea0bb1): kobject_uevent_env >> [ 4835.952424] kobject: 'gpio_sim' (0000000096ea0bb1): fill_kobj_path: path = '/module/gpio_sim' >> [ 4835.952445] kobject: 'gpio_sim' (0000000096ea0bb1): calling ktype release >> [ 4835.952448] kobject: 'gpio_sim': free name >> >> Or, with CONFIG_DEBUG_DEVRES=y, it looks like this: > > I don't see that been enabled (it requires to pass a command line option to the kernel). I don't think I have found this command line option to LK. So far it seems that the kobject_release() was called for both /bus/platform/drivers/gpio-sim and /module/gpio_sim . Is there soemthing I'm missing? However, I've found one relatively unrelated failure to call kobject_release(). This happens during shutdown, after the syslog is shutdown, so I can only provide a screenshot as a proof and for diagnostics: https://domac.alu.hr/~mtodorov/linux/bugreports/integrity/20230308_123748.jpg https://domac.alu.hr/~mtodorov/linux/bugreports/integrity/20230308_123752.jpg I failed to locate the driver and responsible maintainers to the present moment. It is happening on shutdown and it isn't that critical IMHO, except if it shows some other problem in the code :-/ >>>>>>> Or maybe the chip->gc.parent should be changed to something else (actual GPIO >>>>>>> device, but then it's unclear how to provide the attributes in non-racy way >>>>>> Really, dunno. I have to repeat that my learning curve cannot adapt so quickly. >>>>>> >>>>>> I merely gave the report of KMEMLEAK, otherwise I am not a Linux kernel >>>>>> device expert nor would be appropriate to try the craft not earned ;-) >> >> With all of these additional debugging, cat /sys/kernel/debug/kmemleak >> showed nothing new. >> >> I believe this is reasonably safe. >> >> However, I was unsuccessful in seeing gpio trace, even with >> echo 1 > /sys/kernel/tracing/events/gpio/enable ... :-/ > > It's available in the trace buffer (you need to read a documentation to > understand how it works). Still working on that, had other tasks to do ... So far I got to this: 1020 echo "1" > /sys/kernel/tracing/events/gpio/enable 1021 more /sys/kernel/tracing/trace 1022 cd ~marvin/linux/kernel/linux_torvalds/tools/testing/selftests/gpio/ 1023 ls 1024 ./gpio-sim.sh 1025 more /sys/kernel/tracing/trace # tracer: nop # # entries-in-buffer/entries-written: 9/9 #P:6 # # _-----=> irqs-off/BH-disabled # / _----=> need-resched # | / _---=> hardirq/softirq # || / _--=> preempt-depth # ||| / _-=> migrate-disable # |||| / delay # TASK-PID CPU# ||||| TIMESTAMP FUNCTION # | | | ||||| | | gpio-sim.sh-21157 [000] ..... 2705.538025: gpio_direction: 560 in (0) gpio-mockup-cde-21471 [000] ..... 2705.579730: gpio_direction: 564 in (0) gpio-mockup-cde-21471 [000] ..... 2705.579745: gpio_value: 564 get 1 gpio-mockup-cde-21478 [003] ..... 2705.589475: gpio_direction: 565 in (0) gpio-mockup-cde-21478 [003] ..... 2705.589488: gpio_value: 565 get 0 gpio-mockup-cde-21561 [003] ..... 2705.721427: gpio_value: 589 set 1 gpio-mockup-cde-21561 [003] ..... 2705.721427: gpio_direction: 589 out (0) gpio-mockup-cde-21595 [000] ..... 2705.855861: gpio_direction: 597 in (0) gpio-mockup-cde-21595 [000] ..... 2705.855875: gpio_value: 597 get 1 [root@pc-mtodorov gpio]# I hope I did this right. However, I have to play a bit with these results before I could make any interpretation. I just wanted to provide some feedback. Regards, Mirsad -- Mirsad Goran Todorovac Sistem inženjer Grafički fakultet | Akademija likovnih umjetnosti Sveučilište u Zagrebu System engineer Faculty of Graphic Arts | Academy of Fine Arts University of Zagreb, Republic of Croatia