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 41BCEC433F5 for ; Mon, 27 Sep 2021 17:34:38 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 21A1260E08 for ; Mon, 27 Sep 2021 17:34:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237795AbhI0RgO (ORCPT ); Mon, 27 Sep 2021 13:36:14 -0400 Received: from mail.kernel.org ([198.145.29.99]:43622 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238122AbhI0RaF (ORCPT ); Mon, 27 Sep 2021 13:30:05 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id CDDF361262; Mon, 27 Sep 2021 17:17:55 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1632763076; bh=jpfmtd47R/F4mGS9s52CrzGTZMmtH1/bvQccjaXRH70=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=lr/UQw1vM4Kqajk15eslgpw7upGevFLRoWCooFGyvSVA1xAB6C6yEKiwJoyqu0XD1 QGvst1s6/QiwR5tqRr11/4Nueme4X/jT3l6J+0DqarWy16voQYIM0wr7OSuzyXvE6/ OClrZ8tDaP7cvN3Wigj5Fc0YkMoC+gZT0l1mXHv0= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Jon Nettleton , Heikki Krogerus , Laurentiu Tudor , "Rafael J. Wysocki" Subject: [PATCH 5.14 157/162] software node: balance refcount for managed software nodes Date: Mon, 27 Sep 2021 19:03:23 +0200 Message-Id: <20210927170238.858470287@linuxfoundation.org> X-Mailer: git-send-email 2.33.0 In-Reply-To: <20210927170233.453060397@linuxfoundation.org> References: <20210927170233.453060397@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Laurentiu Tudor commit 5aeb05b27f81269a2bf2e15eab9fc0f9a400d3a8 upstream. 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. [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+ # 5.12+ [ rjw: Fix up the software_node_notify() invocation ] Signed-off-by: Rafael J. Wysocki Signed-off-by: Greg Kroah-Hartman --- drivers/base/swnode.c | 3 +++ 1 file changed, 3 insertions(+) --- a/drivers/base/swnode.c +++ b/drivers/base/swnode.c @@ -1113,6 +1113,9 @@ int device_create_managed_software_node( to_swnode(fwnode)->managed = true; set_secondary_fwnode(dev, fwnode); + if (device_is_registered(dev)) + software_node_notify(dev, KOBJ_ADD); + return 0; } EXPORT_SYMBOL_GPL(device_create_managed_software_node);