/* * Copyright (c) 2007-2012 Nicira, Inc. * * This program is free software; you can redistribute it and/or * modify it under the terms of version 2 of the GNU General Public * License as published by the Free Software Foundation. * * This program is distributed in the hope that it will be useful, but * WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA * 02110-1301, USA */ #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt #include #include #include #include #include #include #include #include #include #include #include #include "datapath.h" #include "vport.h" #include "vport-internal_dev.h" #include "vport-netdev.h" static struct vport_ops ovs_netdev_vport_ops; /* Must be called with rcu_read_lock. */ static void netdev_port_receive(struct sk_buff *skb) { struct vport *vport; vport = ovs_netdev_get_vport(skb->dev); if (unlikely(!vport)) goto error; if (unlikely(skb_warn_if_lro(skb))) goto error; /* Make our own copy of the packet. Otherwise we will mangle the * packet for anyone who came before us (e.g. tcpdump via AF_PACKET). */ skb = skb_share_check(skb, GFP_ATOMIC); if (unlikely(!skb)) return; if (skb->dev->type == ARPHRD_ETHER) { skb_push(skb, ETH_HLEN); skb_postpush_rcsum(skb, skb->data, ETH_HLEN); } ovs_vport_receive(vport, skb, skb_tunnel_info(skb)); return; error: kfree_skb(skb); } /* Called with rcu_read_lock and bottom-halves disabled. */ static rx_handler_result_t netdev_frame_hook(struct sk_buff **pskb) { struct sk_buff *skb = *pskb; if (unlikely(skb->pkt_type == PACKET_LOOPBACK)) return RX_HANDLER_PASS; netdev_port_receive(skb); return RX_HANDLER_CONSUMED; } static struct net_device *get_dpdev(const struct datapath *dp) { struct vport *local; local = ovs_vport_ovsl(dp, OVSP_LOCAL); BUG_ON(!local); return local->dev; } struct vport *ovs_netdev_link(struct vport *vport, const char *name) { int err; vport->dev = dev_get_by_name(ovs_dp_get_net(vport->dp), name); if (!vport->dev) { err = -ENODEV; goto error_free_vport; } if (vport->dev->flags & IFF_LOOPBACK || (vport->dev->type != ARPHRD_ETHER && vport->dev->type != ARPHRD_NONE) || ovs_is_internal_dev(vport->dev)) { err = -EINVAL; goto error_put; } rtnl_lock(); err = netdev_master_upper_dev_link(vport->dev, get_dpdev(vport->dp), NULL, NULL); if (err) goto error_unlock; err = netdev_rx_handler_register(vport->dev, netdev_frame_hook, vport); if (err) goto error_master_upper_dev_unlink; dev_disable_lro(vport->dev); dev_set_promiscuity(vport->dev, 1); vport->dev->priv_flags |= IFF_OVS_DATAPATH; rtnl_unlock(); return vport; error_master_upper_dev_unlink: netdev_upper_dev_unlink(vport->dev, get_dpdev(vport->dp)); error_unlock: rtnl_unlock(); error_put: dev_put(vport->dev); error_free_vport: ovs_vport_free(vport); return ERR_PTR(err); } EXPORT_SYMBOL_GPL(ovs_netdev_link); static struct vport *netdev_create(const struct vport_parms *parms) { struct vport *vport; vport = ovs_vport_alloc(0, &ovs_netdev_vport_ops, parms); if (IS_ERR(vport)) return vport; return ovs_netdev_link(vport, parms->name); } static void vport_netdev_free(struct rcu_head *rcu) { struct vport *vport = container_of(rcu, struct vport, rcu); if (vport->dev) dev_put(vport->dev); ovs_vport_free(vport); } void ovs_netdev_detach_dev(struct vport *vport) { ASSERT_RTNL(); vport->dev->priv_flags &= ~IFF_OVS_DATAPATH; netdev_rx_handler_unregister(vport->dev); netdev_upper_dev_unlink(vport->dev, netdev_master_upper_dev_get(vport->dev)); dev_set_promiscuity(vport->dev, -1); } static void netdev_destroy(struct vport *vport) { rtnl_lock(); if (vport->dev->priv_flags & IFF_OVS_DATAPATH) ovs_netdev_detach_dev(vport); rtnl_unlock(); call_rcu(&vport->rcu, vport_netdev_free); } void ovs_netdev_tunnel_destroy(struct vport *vport) { rtnl_lock(); if (vport->dev->priv_flags & IFF_OVS_DATAPATH) ovs_netdev_detach_dev(vport); /* We can be invoked by both explicit vport deletion and * underlying netdev deregistration; delete the link only * if it's not already shutting down. */ if (vport->dev->reg_state == NETREG_REGISTERED) rtnl_delete_link(vport->dev); dev_put(vport->dev); vport->dev = NULL; rtnl_unlock(); call_rcu(&vport->rcu, vport_netdev_free); } EXPORT_SYMBOL_GPL(ovs_netdev_tunnel_destroy); /* Returns null if this device is not attached to a datapath. */ struct vport *ovs_netdev_get_vport(struct net_device *dev) { if (likely(dev->priv_flags & IFF_OVS_DATAPATH)) return (struct vport *) rcu_dereference_rtnl(dev->rx_handler_data); else return NULL; } static struct vport_ops ovs_netdev_vport_ops = { .type = OVS_VPORT_TYPE_NETDEV, .create = netdev_create, .destroy = netdev_destroy, .send = dev_queue_xmit, }; int __init ovs_netdev_init(void) { return ovs_vport_ops_register(&ovs_netdev_vport_ops); } void ovs_netdev_exit(void) { ovs_vport_ops_unregister(&ovs_netdev_vport_ops); } ss='oid'>2c5d9555d6d937966d79d4c6529a5f7b9206e405 (diff)
drm/i915: Check for NULL i915_vma in intel_unpin_fb_obj()
I've seen this trigger twice now, where the i915_gem_object_to_ggtt() call in intel_unpin_fb_obj() returns NULL, resulting in an oops immediately afterwards as the (inlined) call to i915_vma_unpin_fence() tries to dereference it. It seems to be some race condition where the object is going away at shutdown time, since both times happened when shutting down the X server. 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/ax25/ax25_uid.c')