Messages in this thread | | | From | Jia-Ju Bai <> | Subject | [BUG] infiniband: sw: rdmavt: possible ABBA deadlocks in rvt_ruc_loopback() | Date | Thu, 20 Oct 2022 21:37:47 +0800 |
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Hello,
My static analysis tool reports several possible ABBA deadlock in the rdmavt driver in Linux 5.18:
rvt_ruc_loopback() spin_lock_irqsave(&sqp->s_lock, flags); --> Line 3190 (Lock A) spin_lock(&sqp->r_lock); --> Line 3195 (Lock B)
rvt_qp_mr_clean() spin_lock_irq(&qp->r_lock); --> Line 698 (Lock B) spin_lock(&qp->s_lock); --> Line 700 (Lock A)
rvt_rc_timeout() spin_lock_irqsave(&qp->r_lock, flags); --> Line 2595 (Lock B) spin_lock(&qp->s_lock); --> Line 2596 (Lock A)
rvt_modify_qp() spin_lock_irq(&qp->r_lock); --> Line 1419 (Lock B) spin_lock(&qp->s_lock); --> Line 1421(Lock A)
_rvt_reset_qp() spin_lock_irq(&qp->r_lock); --> Line 907 (Lock B) spin_lock(&qp->s_lock); --> Line 909 (Lock A)
rvt_reset_qp() spin_lock_irq(&qp->r_lock); --> Line 936 (Lock B) spin_lock(&qp->s_lock); --> Line 938 (Lock A)
When rvt_ruc_loopback() is concurrently executed with rvt_qp_mr_clean(), rvt_rc_timeout(), rvt_modify_qp(), _rvt_reset_qp() or rvt_reset_qp(), the deadlocks can occur.
I am not quite sure whether these possible deadlocks are real and how to fix them if real. Any feedback would be appreciated, thanks :)
Reported-by: TOTE Robot <oslab@tsinghua.edu.cn>
Best wishes, Jia-Ju Bai
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