/* * Linux network device link state notification * * Author: * Stefan Rompf * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License * as published by the Free Software Foundation; either version * 2 of the License, or (at your option) any later version. * */ #include #include #include #include #include #include #include #include #include #include #include enum lw_bits { LW_URGENT = 0, }; static unsigned long linkwatch_flags; static unsigned long linkwatch_nextevent; static void linkwatch_event(struct work_struct *dummy); static DECLARE_DELAYED_WORK(linkwatch_work, linkwatch_event); static LIST_HEAD(lweventlist); static DEFINE_SPINLOCK(lweventlist_lock); static unsigned char default_operstate(const struct net_device *dev) { if (!netif_carrier_ok(dev)) return (dev->ifindex != dev_get_iflink(dev) ? IF_OPER_LOWERLAYERDOWN : IF_OPER_DOWN); if (netif_dormant(dev)) return IF_OPER_DORMANT; return IF_OPER_UP; } static void rfc2863_policy(struct net_device *dev) { unsigned char operstate = default_operstate(dev); if (operstate == dev->operstate) return; write_lock_bh(&dev_base_lock); switch(dev->link_mode) { case IF_LINK_MODE_DORMANT: if (operstate == IF_OPER_UP) operstate = IF_OPER_DORMANT; break; case IF_LINK_MODE_DEFAULT: default: break; } dev->operstate = operstate; write_unlock_bh(&dev_base_lock); } void linkwatch_init_dev(struct net_device *dev) { /* Handle pre-registration link state changes */ if (!netif_carrier_ok(dev) || netif_dormant(dev)) rfc2863_policy(dev); } static bool linkwatch_urgent_event(struct net_device *dev) { if (!netif_running(dev)) return false; if (dev->ifindex != dev_get_iflink(dev)) return true; if (dev->priv_flags & IFF_TEAM_PORT) return true; return netif_carrier_ok(dev) && qdisc_tx_changing(dev); } static void linkwatch_add_event(struct net_device *dev) { unsigned long flags; spin_lock_irqsave(&lweventlist_lock, flags); if (list_empty(&dev->link_watch_list)) { list_add_tail(&dev->link_watch_list, &lweventlist); dev_hold(dev); } spin_unlock_irqrestore(&lweventlist_lock, flags); } static void linkwatch_schedule_work(int urgent) { unsigned long delay = linkwatch_nextevent - jiffies; if (test_bit(LW_URGENT, &linkwatch_flags)) return; /* Minimise down-time: drop delay for up event. */ if (urgent) { if (test_and_set_bit(LW_URGENT, &linkwatch_flags)) return; delay = 0; } /* If we wrap around we'll delay it by at most HZ. */ if (delay > HZ) delay = 0; /* * If urgent, schedule immediate execution; otherwise, don't * override the existing timer. */ if (test_bit(LW_URGENT, &linkwatch_flags)) mod_delayed_work(system_wq, &linkwatch_work, 0); else schedule_delayed_work(&linkwatch_work, delay); } static void linkwatch_do_dev(struct net_device *dev) { /* * Make sure the above read is complete since it can be * rewritten as soon as we clear the bit below. */ smp_mb__before_atomic(); /* We are about to handle this device, * so new events can be accepted */ clear_bit(__LINK_STATE_LINKWATCH_PENDING, &dev->state); rfc2863_policy(dev); if (dev->flags & IFF_UP) { if (netif_carrier_ok(dev)) dev_activate(dev); else dev_deactivate(dev); netdev_state_change(dev); } dev_put(dev); } static void __linkwatch_run_queue(int urgent_only) { struct net_device *dev; LIST_HEAD(wrk); /* * Limit the number of linkwatch events to one * per second so that a runaway driver does not * cause a storm of messages on the netlink * socket. This limit does not apply to up events * while the device qdisc is down. */ if (!urgent_only) linkwatch_nextevent = jiffies + HZ; /* Limit wrap-around effect on delay. */ else if (time_after(linkwatch_nextevent, jiffies + HZ)) linkwatch_nextevent = jiffies; clear_bit(LW_URGENT, &linkwatch_flags); spin_lock_irq(&lweventlist_lock); list_splice_init(&lweventlist, &wrk); while (!list_empty(&wrk)) { dev = list_first_entry(&wrk, struct net_device, link_watch_list); list_del_init(&dev->link_watch_list); if (urgent_only && !linkwatch_urgent_event(dev)) { list_add_tail(&dev->link_watch_list, &lweventlist); continue; } spin_unlock_irq(&lweventlist_lock); linkwatch_do_dev(dev); spin_lock_irq(&lweventlist_lock); } if (!list_empty(&lweventlist)) linkwatch_schedule_work(0); spin_unlock_irq(&lweventlist_lock); } void linkwatch_forget_dev(struct net_device *dev) { unsigned long flags; int clean = 0; spin_lock_irqsave(&lweventlist_lock, flags); if (!list_empty(&dev->link_watch_list)) { list_del_init(&dev->link_watch_list); clean = 1; } spin_unlock_irqrestore(&lweventlist_lock, flags); if (clean) linkwatch_do_dev(dev); } /* Must be called with the rtnl semaphore held */ void linkwatch_run_queue(void) { __linkwatch_run_queue(0); } static void linkwatch_event(struct work_struct *dummy) { rtnl_lock(); __linkwatch_run_queue(time_after(linkwatch_nextevent, jiffies)); rtnl_unlock(); } void linkwatch_fire_event(struct net_device *dev) { bool urgent = linkwatch_urgent_event(dev); if (!test_and_set_bit(__LINK_STATE_LINKWATCH_PENDING, &dev->state)) { linkwatch_add_event(dev); } else if (!urgent) return; linkwatch_schedule_work(urgent); } EXPORT_SYMBOL(linkwatch_fire_event); 7ab654a4b94fc&id2=2f5a31456ee80b37ef1170319fa134af0a1dfcc4'>diff)parentffb58456589443ca572221fabbdef3db8483a779 (diff)
Merge remote-tracking branch 'mkp-scsi/fixes' into fixes
Diffstat (limited to 'include/memory')
The call chains were different: - VT ioctl(KDSETMODE, KD_TEXT): intel_cleanup_plane_fb+0x5b/0xa0 [i915] drm_atomic_helper_cleanup_planes+0x6f/0x90 [drm_kms_helper] intel_atomic_commit_tail+0x749/0xfe0 [i915] intel_atomic_commit+0x3cb/0x4f0 [i915] drm_atomic_commit+0x4b/0x50 [drm] restore_fbdev_mode+0x14c/0x2a0 [drm_kms_helper] drm_fb_helper_restore_fbdev_mode_unlocked+0x34/0x80 [drm_kms_helper] drm_fb_helper_set_par+0x2d/0x60 [drm_kms_helper] intel_fbdev_set_par+0x18/0x70 [i915] fb_set_var+0x236/0x460 fbcon_blank+0x30f/0x350 do_unblank_screen+0xd2/0x1a0 vt_ioctl+0x507/0x12a0 tty_ioctl+0x355/0xc30 do_vfs_ioctl+0xa3/0x5e0 SyS_ioctl+0x79/0x90 entry_SYSCALL_64_fastpath+0x13/0x94 - i915 unpin_work workqueue: intel_unpin_work_fn+0x58/0x140 [i915] process_one_work+0x1f1/0x480 worker_thread+0x48/0x4d0 kthread+0x101/0x140 and this patch purely papers over the issue by adding a NULL pointer check and a WARN_ON_ONCE() to avoid the oops that would then generally make the machine unresponsive. Other callers of i915_gem_object_to_ggtt() seem to also check for the returned pointer being NULL and warn about it, so this clearly has happened before in other places. [ Reported it originally to the i915 developers on Jan 8, applying the ugly workaround on my own now after triggering the problem for the second time with no feedback. This is likely to be the same bug reported as https://bugs.freedesktop.org/show_bug.cgi?id=98829 https://bugs.freedesktop.org/show_bug.cgi?id=99134 which has a patch for the underlying problem, but it hasn't gotten to me, so I'm applying the workaround. ] Cc: Daniel Vetter <daniel.vetter@intel.com> Cc: Jani Nikula <jani.nikula@linux.intel.com> Cc: Ville Syrjälä <ville.syrjala@linux.intel.com> Cc: Chris Wilson <chris@chris-wilson.co.uk> Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com> Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com> Cc: Imre Deak <imre.deak@intel.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'net/ieee802154/sysfs.h')