Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751731AbZIWN4q (ORCPT ); Wed, 23 Sep 2009 09:56:46 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751185AbZIWN4p (ORCPT ); Wed, 23 Sep 2009 09:56:45 -0400 Received: from smtp.ispras.ru ([83.149.198.201]:60342 "EHLO smtp.ispras.ru" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751179AbZIWN4o (ORCPT ); Wed, 23 Sep 2009 09:56:44 -0400 Content-Disposition: inline From: iceberg Organization: ISP RAS To: James.Bottomley@hansenpartnership.com, eric@andante.org, linux-scsi@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH] scsi_lib.c: sleeping function called from invalid context Date: Wed, 23 Sep 2009 17:58:47 +0000 User-Agent: KMail/1.10.3 (Linux/2.6.27.29-0.1-default; KDE/4.1.3; x86_64; ; ) MIME-Version: 1.0 Content-Type: Text/Plain; charset="utf-8" Content-Transfer-Encoding: 7bit Message-Id: <200909231758.47612.strakh@ispras.ru> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1978 Lines: 50 Driver scsi_lib.c might sleep in atomic context, because it calls scsi_device_put under spin_lock_irqsave. drivers/scsi/scsi_lib.c:356: spin_lock_irqsave(shost->host_lock, flags); scsi_device_put(sdev); 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: 4.1 kobject_cleanup calls kobject_uevent at ./lib/kobject.c:555 4.2 kobject_uevent calls kobject_uevent_env at ./lib/kobject_uevent.c:282 4.3 kobject_uevent_env calls call_usermodehelper_exec at ./include/linux/kmod.h:83 4.4 call_usermodehelper_exec calls wait_for_completion at ./kernel/kmod.c:481 4.5 wait_for_completion calls wait_for_common at ./kernel/sched.c:5710 4.5 wait_for_common calls might_sleep at ./kernels/sched.c:5692 Found by Linux Driver Verification project. Delete wrong sleeping function calls. Signed-off-by: Alexander Strakh --- diff --git a/./a/drivers/scsi/scsi_lib.c b/./b/drivers/scsi/scsi_lib.c index f3c4089..a8f8e2f 100644 --- a/./a/drivers/scsi/scsi_lib.c +++ b/./b/drivers/scsi/scsi_lib.c @@ -353,9 +353,9 @@ static void scsi_single_lun_run(struct scsi_device *current_sdev) spin_unlock_irqrestore(shost->host_lock, flags); blk_run_queue(sdev->request_queue); - spin_lock_irqsave(shost->host_lock, flags); - scsi_device_put(sdev); + scsi_device_put(sdev); + spin_lock_irqsave(shost->host_lock, flags); } out: spin_unlock_irqrestore(shost->host_lock, flags); -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/