Messages in this thread | | | From | Jia-Ju Bai <> | Subject | [BUG] scsi: lpfc: possible ABBCCA deadlock involving three threads | Date | Mon, 23 Aug 2021 19:31:55 +0800 |
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Hello,
My static analysis tool reports a possible ABBCCA deadlock in the lpfc driver in Linux 5.10:
lpfc_els_flush_cmd() spin_lock(&pring->ring_lock); --> line 8124 (Lock A) lpfc_sli_cancel_iocbs() lpfc_sli_release_iocbq() spin_lock_irqsave(&phba->hbalock, iflags); --> line 1384 (Lock B)
lpfc_sli_abort_taskmgmt() spin_lock_irqsave(&phba->hbalock, iflags); --> line 11812 (Lock B) spin_lock(&lpfc_cmd->buf_lock); --> line 11830 (Lock C)
lpfc_abort_handler() spin_lock(&lpfc_cmd->buf_lock); --> line 4760 (Lock C) spin_lock(&pring_s4->ring_lock); --> line 4777 (Lock A)
When lpfc_els_flush_cmd(), lpfc_sli_abort_taskmgmt() and lpfc_abort_handler() are concurrently executed, the deadlock can occur.
I am not quite sure whether this possible deadlock is real and how to fix it if it is real. Any feedback would be appreciated, thanks :)
Reported-by: TOTE Robot <oslab@tsinghua.edu.cn>
Best wishes, Jia-Ju Bai
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