On 01/02/2022 08:51, Jia-Ju Bai wrote: > Hello, > > My static analysis tool reports a possible deadlock in the smc module in Linux 5.16: > > smc_lgr_free() > mutex_lock(&lgr->llc_conf_mutex); --> Line 1289 (Lock A) > smcr_link_clear() > smc_wr_free_link() > wait_event(lnk->wr_tx_wait, ...); --> Line 648 (Wait X) > > smc_link_down_work() > mutex_lock(&lgr->llc_conf_mutex); --> Line 1683 (Lock A) > smcr_link_down() > smcr_link_clear() > smc_wr_free_link() > smc_wr_wakeup_tx_wait() > wake_up_all(&lnk->wr_tx_wait); --> Line 78 (Wake X) > > When smc_lgr_free() is executed, "Wait X" is performed by holding "Lock A". If smc_link_down_work() is executed at this time, "Wake X" cannot be performed to wake up "Wait X" in smc_lgr_free(), because "Lock A" has been already hold by smc_lgr_free(), causing a possible deadlock. > Thank you for your reporting and the good description! We will look into this issue and get back to you in a few days.
