From mboxrd@z Thu Jan 1 00:00:00 1970 From: iceberg Subject: [BUG] sg.c: sleeping function called from invalid context Date: Thu, 1 Oct 2009 16:28:05 +0000 Message-ID: <200910011628.06870.strakh@ispras.ru> Mime-Version: 1.0 Content-Type: Text/Plain; charset="utf-8" Content-Transfer-Encoding: 7bit Return-path: Received: from smtp.ispras.ru ([83.149.198.201]:58964 "EHLO smtp.ispras.ru" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932166AbZJAMZ3 (ORCPT ); Thu, 1 Oct 2009 08:25:29 -0400 Content-Disposition: inline Sender: linux-scsi-owner@vger.kernel.org List-Id: linux-scsi@vger.kernel.org To: dgilbert@interlog.com, linux-scsi@vger.kernel.org, linux-kernel@vger.kernel.org KERNEL_VERSION: 2.6.31 DESCRIBE: Driver sg.c might sleep in atomic context, because it calls scsi_device_put under lock_kernel. /drivers/scsi/sg.c:306: static int sg_open(struct inode *inode, struct file *filp) { ... lock_kernel(); ... error_out: if (retval) scsi_device_put(sdp->device); ... Path to might_sleep macro from scsi_device_put: 1. scsi_device_put calls put_device at ./drivers/scsi/scsi.c:1111 2. put_device calls kobject_put at ./drivers/base/core.c:1038 3. kobject_put calls kref_put at ./lib/kobject.c 4. kref_put may call callback function kobject_release at ./lib/kref.c if refcount becomes zero, which might_sleep because it calls user event. Details: 5.1 kobject_cleanup calls kobject_uevent at ./lib/kobject.c:555 5.2 kobject_uevent calls kobject_uevent_env at ./lib/kobject_uevent.c:282 5.3 kobject_uevent_env calls call_usermodehelper_exec at include/linux/kmod.h:83 5.4 call_usermodehelper_exec calls wait_for_completion at ./kernel/kmod.c:481 5.5 wait_for_completion calls wait_for_common at ./kernel/sched.c:5710 5.6 wait_for_common calls might_sleep at ./kernels/sched.c:5692 Found by: Linux Driver Verification