#include #include #include "ieee80211_i.h" #include "mesh.h" #include "driver-ops.h" #include "led.h" static void ieee80211_sched_scan_cancel(struct ieee80211_local *local) { if (ieee80211_request_sched_scan_stop(local)) return; cfg80211_sched_scan_stopped_rtnl(local->hw.wiphy); } int __ieee80211_suspend(struct ieee80211_hw *hw, struct cfg80211_wowlan *wowlan) { struct ieee80211_local *local = hw_to_local(hw); struct ieee80211_sub_if_data *sdata; struct sta_info *sta; if (!local->open_count) goto suspend; ieee80211_scan_cancel(local); ieee80211_dfs_cac_cancel(local); ieee80211_roc_purge(local, NULL); ieee80211_del_virtual_monitor(local); if (ieee80211_hw_check(hw, AMPDU_AGGREGATION) && !(wowlan && wowlan->any)) { mutex_lock(&local->sta_mtx); list_for_each_entry(sta, &local->sta_list, list) { set_sta_flag(sta, WLAN_STA_BLOCK_BA); ieee80211_sta_tear_down_BA_sessions( sta, AGG_STOP_LOCAL_REQUEST); } mutex_unlock(&local->sta_mtx); } /* keep sched_scan only in case of 'any' trigger */ if (!(wowlan && wowlan->any)) ieee80211_sched_scan_cancel(local); ieee80211_stop_queues_by_reason(hw, IEEE80211_MAX_QUEUE_MAP, IEEE80211_QUEUE_STOP_REASON_SUSPEND, false); /* flush out all packets */ synchronize_net(); ieee80211_flush_queues(local, NULL, true); local->quiescing = true; /* make quiescing visible to timers everywhere */ mb(); flush_workqueue(local->workqueue); /* Don't try to run timers while suspended. */ del_timer_sync(&local->sta_cleanup); /* * Note that this particular timer doesn't need to be * restarted at resume. */ cancel_work_sync(&local->dynamic_ps_enable_work); del_timer_sync(&local->dynamic_ps_timer); local->wowlan = wowlan; if (local->wowlan) { int err; /* Drivers don't expect to suspend while some operations like * authenticating or associating are in progress. It doesn't * make sense anyway to accept that, since the authentication * or association would never finish since the driver can't do * that on its own. * Thus, clean up in-progress auth/assoc first. */ list_for_each_entry(sdata, &local->interfaces, list) { if (!ieee80211_sdata_running(sdata)) continue; if (sdata->vif.type != NL80211_IFTYPE_STATION) continue; ieee80211_mgd_quiesce(sdata); /* If suspended during TX in progress, and wowlan * is enabled (connection will be active) there * can be a race where the driver is put out * of power-save due to TX and during suspend * dynamic_ps_timer is cancelled and TX packet * is flushed, leaving the driver in ACTIVE even * after resuming until dynamic_ps_timer puts * driver back in DOZE. */ if (sdata->u.mgd.associated && sdata->u.mgd.powersave && !(local->hw.conf.flags & IEEE80211_CONF_PS)) { local->hw.conf.flags |= IEEE80211_CONF_PS; ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_PS); } } err = drv_suspend(local, wowlan); if (err < 0) { local->quiescing = false; local->wowlan = false; if (ieee80211_hw_check(hw, AMPDU_AGGREGATION)) { mutex_lock(&local->sta_mtx); list_for_each_entry(sta, &local->sta_list, list) { clear_sta_flag(sta, WLAN_STA_BLOCK_BA); } mutex_unlock(&local->sta_mtx); } ieee80211_wake_queues_by_reason(hw, IEEE80211_MAX_QUEUE_MAP, IEEE80211_QUEUE_STOP_REASON_SUSPEND, false); return err; } else if (err > 0) { WARN_ON(err != 1); /* cfg80211 will call back into mac80211 to disconnect * all interfaces, allow that to proceed properly */ ieee80211_wake_queues_by_reason(hw, IEEE80211_MAX_QUEUE_MAP, IEEE80211_QUEUE_STOP_REASON_SUSPEND, false); return err; } else { goto suspend; } } /* remove all interfaces that were created in the driver */ list_for_each_entry(sdata, &local->interfaces, list) { if (!ieee80211_sdata_running(sdata)) continue; switch (sdata->vif.type) { case NL80211_IFTYPE_AP_VLAN: case NL80211_IFTYPE_MONITOR: continue; case NL80211_IFTYPE_STATION: ieee80211_mgd_quiesce(sdata); break; case NL80211_IFTYPE_WDS: /* tear down aggregation sessions and remove STAs */ mutex_lock(&local->sta_mtx); sta = sdata->u.wds.sta; if (sta && sta->uploaded) { enum ieee80211_sta_state state; state = sta->sta_state; for (; state > IEEE80211_STA_NOTEXIST; state--) WARN_ON(drv_sta_state(local, sta->sdata, sta, state, state - 1)); } mutex_unlock(&local->sta_mtx); break; default: break; } drv_remove_interface(local, sdata); } /* * We disconnected on all interfaces before suspend, all channel * contexts should be released. */ WARN_ON(!list_empty(&local->chanctx_list)); /* stop hardware - this must stop RX */ ieee80211_stop_device(local); suspend: local->suspended = true; /* need suspended to be visible before quiescing is false */ barrier(); local->quiescing = false; return 0; } /* * __ieee80211_resume() is a static inline which just calls * ieee80211_reconfig(), which is also needed for hardware * hang/firmware failure/etc. recovery. */ void ieee80211_report_wowlan_wakeup(struct ieee80211_vif *vif, struct cfg80211_wowlan_wakeup *wakeup, gfp_t gfp) { struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif); cfg80211_report_wowlan_wakeup(&sdata->wdev, wakeup, gfp); } EXPORT_SYMBOL(ieee80211_report_wowlan_wakeup); c219c9dc4616da52d /include/video parent1b1bc42c1692e9b62756323c675a44cb1a1f9dbd (diff)
percpu-refcount: fix reference leak during percpu-atomic transition
percpu_ref_tryget() and percpu_ref_tryget_live() should return "true" IFF they acquire a reference. But the return value from atomic_long_inc_not_zero() is a long and may have high bits set, e.g. PERCPU_COUNT_BIAS, and the return value of the tryget routines is bool so the reference may actually be acquired but the routines return "false" which results in a reference leak since the caller assumes it does not need to do a corresponding percpu_ref_put(). This was seen when performing CPU hotplug during I/O, as hangs in blk_mq_freeze_queue_wait where percpu_ref_kill (blk_mq_freeze_queue_start) raced with percpu_ref_tryget (blk_mq_timeout_work). Sample stack trace: __switch_to+0x2c0/0x450 __schedule+0x2f8/0x970 schedule+0x48/0xc0 blk_mq_freeze_queue_wait+0x94/0x120 blk_mq_queue_reinit_work+0xb8/0x180 blk_mq_queue_reinit_prepare+0x84/0xa0 cpuhp_invoke_callback+0x17c/0x600 cpuhp_up_callbacks+0x58/0x150 _cpu_up+0xf0/0x1c0 do_cpu_up+0x120/0x150 cpu_subsys_online+0x64/0xe0 device_online+0xb4/0x120 online_store+0xb4/0xc0 dev_attr_store+0x68/0xa0 sysfs_kf_write+0x80/0xb0 kernfs_fop_write+0x17c/0x250 __vfs_write+0x6c/0x1e0 vfs_write+0xd0/0x270 SyS_write+0x6c/0x110 system_call+0x38/0xe0 Examination of the queue showed a single reference (no PERCPU_COUNT_BIAS, and __PERCPU_REF_DEAD, __PERCPU_REF_ATOMIC set) and no requests. However, conditions at the time of the race are count of PERCPU_COUNT_BIAS + 0 and __PERCPU_REF_DEAD and __PERCPU_REF_ATOMIC set. The fix is to make the tryget routines use an actual boolean internally instead of the atomic long result truncated to a int. Fixes: e625305b3907 percpu-refcount: make percpu_ref based on longs instead of ints Link: https://bugzilla.kernel.org/show_bug.cgi?id=190751 Signed-off-by: Douglas Miller <dougmill@linux.vnet.ibm.com> Reviewed-by: Jens Axboe <axboe@fb.com> Signed-off-by: Tejun Heo <tj@kernel.org> Fixes: e625305b3907 ("percpu-refcount: make percpu_ref based on longs instead of ints") Cc: stable@vger.kernel.org # v3.18+
Diffstat (limited to 'include/video')