From: James Bottomley <jejb@linux.vnet.ibm.com>
To: Jia-Ju Bai <baijiaju1990@gmail.com>,
qla2xxx-upstream@qlogic.com, martin.petersen@oracle.com
Cc: linux-scsi@vger.kernel.org,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: [BUG] scsi/qla2xxx: a possible sleep-in-atomic bug in qlt_get_tag
Date: Tue, 12 Dec 2017 20:42:01 -0800 [thread overview]
Message-ID: <1513140121.3110.78.camel@linux.vnet.ibm.com> (raw)
In-Reply-To: <0363371c-db1c-169f-df5f-ca15b3839e41@gmail.com>
On Wed, 2017-12-13 at 11:18 +0800, Jia-Ju Bai wrote:
> The driver may sleep under a spinlock.
> The function call paths are:
> qlt_handle_abts_recv_work (acquire the spinlock)
> qlt_response_pkt_all_vps
> qlt_response_pkt
> qlt_handle_cmd_for_atio
> qlt_get_tag
> percpu_ida_alloc --> may sleep
>
> qla82xx_msix_rsp_q (acquire the spinlock)
> qla24xx_process_response_queue
> qlt_handle_abts_recv
> qlt_response_pkt_all_vps
> qlt_response_pkt
> qlt_handle_cmd_for_atio
> qlt_get_tag
> percpu_ida_alloc --> may sleep-in-atomic
>
> qla24xx_intr_handler (acquire the spinlock)
> qla24xx_process_response_queue
> qlt_handle_abts_recv
> qlt_response_pkt
> qlt_handle_cmd_for_atio
> qlt_get_tag
> percpu_ida_alloc --> may sleep
>
> I do not find a good way to fix it, so I only report.
> This possible bug is found by my static analysis tool (DSAC) and
> checked by my code review.
The report is incorrect: percpu_ida_alloc with state==TASK_RUNNING is
atomic (and interrupt) safe which appears to be the case here.
James
next prev parent reply other threads:[~2017-12-13 4:42 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-12-13 3:18 [BUG] scsi/qla2xxx: a possible sleep-in-atomic bug in qlt_get_tag Jia-Ju Bai
2017-12-13 4:42 ` James Bottomley [this message]
2017-12-13 7:38 ` Jia-Ju Bai
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