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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 09C84C433F5 for ; Mon, 27 Sep 2021 13:37:07 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D89736109F for ; Mon, 27 Sep 2021 13:37:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233721AbhI0Nio (ORCPT ); Mon, 27 Sep 2021 09:38:44 -0400 Received: from mga04.intel.com ([192.55.52.120]:29474 "EHLO mga04.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234114AbhI0Nik (ORCPT ); Mon, 27 Sep 2021 09:38:40 -0400 X-IronPort-AV: E=McAfee;i="6200,9189,10119"; a="222585651" X-IronPort-AV: E=Sophos;i="5.85,326,1624345200"; d="scan'208";a="222585651" Received: from fmsmga001.fm.intel.com ([10.253.24.23]) by fmsmga104.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 27 Sep 2021 06:37:03 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.85,326,1624345200"; d="scan'208";a="615770247" Received: from kuha.fi.intel.com ([10.237.72.162]) by fmsmga001.fm.intel.com with SMTP; 27 Sep 2021 06:37:00 -0700 Received: by kuha.fi.intel.com (sSMTP sendmail emulation); Mon, 27 Sep 2021 16:36:59 +0300 Date: Mon, 27 Sep 2021 16:36:59 +0300 From: Heikki Krogerus To: Laurentiu Tudor Cc: Greg KH , jon@solid-run.com, rafael.j.wysocki@intel.com, stable@vger.kernel.org Subject: Re: [PATCH] software node: balance refcount for managed sw nodes Message-ID: References: <20210927102249.12939-1-laurentiu.tudor@nxp.com> <97a611be-3deb-111e-5619-f0f015393e24@nxp.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <97a611be-3deb-111e-5619-f0f015393e24@nxp.com> Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org On Mon, Sep 27, 2021 at 03:42:42PM +0300, Laurentiu Tudor wrote: > > On 9/27/2021 3:17 PM, Greg KH wrote: > > On Mon, Sep 27, 2021 at 01:22:49PM +0300, Laurentiu Tudor wrote: > >> software_node_notify(), on KOBJ_REMOVE drops the refcount twice on managed > >> software nodes, thus leading to underflow errors. Balance the refcount by > >> bumping it in the device_create_managed_software_node() function. > >> > >> The error [1] was encountered after adding a .shutdown() op to our > >> fsl-mc-bus driver. > >> > >> [Backported to stable from mainline commit > >> 5aeb05b27f81 ("software node: balance refcount for managed software nodes")] > > But ... > > >> [1] > >> pc : refcount_warn_saturate+0xf8/0x150 > >> lr : refcount_warn_saturate+0xf8/0x150 > >> sp : ffff80001009b920 > >> x29: ffff80001009b920 x28: ffff1a2420318000 x27: 0000000000000000 > >> x26: ffffccac15e7a038 x25: 0000000000000008 x24: ffffccac168e0030 > >> x23: ffff1a2428a82000 x22: 0000000000080000 x21: ffff1a24287b5000 > >> x20: 0000000000000001 x19: ffff1a24261f4400 x18: ffffffffffffffff > >> x17: 6f72645f726f7272 x16: 0000000000000000 x15: ffff80009009b607 > >> x14: 0000000000000000 x13: ffffccac16602670 x12: 0000000000000a17 > >> x11: 000000000000035d x10: ffffccac16602670 x9 : ffffccac16602670 > >> x8 : 00000000ffffefff x7 : ffffccac1665a670 x6 : ffffccac1665a670 > >> x5 : 0000000000000000 x4 : 0000000000000000 x3 : 00000000ffffffff > >> x2 : 0000000000000000 x1 : 0000000000000000 x0 : ffff1a2420318000 > >> Call trace: > >> refcount_warn_saturate+0xf8/0x150 > >> kobject_put+0x10c/0x120 > >> software_node_notify+0xd8/0x140 > >> device_platform_notify+0x4c/0xb4 > >> device_del+0x188/0x424 > >> fsl_mc_device_remove+0x2c/0x4c > >> rebofind sp.c__fsl_mc_device_remove+0x14/0x2c > >> device_for_each_child+0x5c/0xac > >> dprc_remove+0x9c/0xc0 > >> fsl_mc_driver_remove+0x28/0x64 > >> __device_release_driver+0x188/0x22c > >> device_release_driver+0x30/0x50 > >> bus_remove_device+0x128/0x134 > >> device_del+0x16c/0x424 > >> fsl_mc_bus_remove+0x8c/0x114 > >> fsl_mc_bus_shutdown+0x14/0x20 > >> platform_shutdown+0x28/0x40 > >> device_shutdown+0x15c/0x330 > >> __do_sys_reboot+0x218/0x2a0 > >> __arm64_sys_reboot+0x28/0x34 > >> invoke_syscall+0x48/0x114 > >> el0_svc_common+0x40/0xdc > >> do_el0_svc+0x2c/0x94 > >> el0_svc+0x2c/0x54 > >> el0t_64_sync_handler+0xa8/0x12c > >> el0t_64_sync+0x198/0x19c > >> ---[ end trace 32eb1c71c7d86821 ]--- > >> > >> Fixes: 151f6ff78cdf ("software node: Provide replacement for device_add_properties()") > >> Reported-by: Jon Nettleton > >> Suggested-by: Heikki Krogerus > >> Reviewed-by: Heikki Krogerus > >> Signed-off-by: Laurentiu Tudor > >> Cc: # 5.12+ > >> --- > >> drivers/base/swnode.c | 3 +++ > >> 1 file changed, 3 insertions(+) > > > > Next time, please include the git commit id of this patch that is > > already in Linus's tree so that I don't have to go and manually look it > > up... > > > > ... i did mention the mainline commit in the description. Maybe there's > a mix up with the previous submission, or i should have used a special > syntax that i'm not aware of... The syntax is defined in the documentation: https://www.kernel.org/doc/html/latest/process/stable-kernel-rules.html > Anyway, thanks for picking this up. thanks, -- heikki