/* * llc_s_ac.c - actions performed during sap state transition. * * Description : * Functions in this module are implementation of sap component actions. * Details of actions can be found in IEEE-802.2 standard document. * All functions have one sap and one event as input argument. All of * them return 0 On success and 1 otherwise. * * Copyright (c) 1997 by Procom Technology, Inc. * 2001-2003 by Arnaldo Carvalho de Melo * * This program can be redistributed or modified under the terms of the * GNU General Public License as published by the Free Software Foundation. * This program is distributed without any warranty or implied warranty * of merchantability or fitness for a particular purpose. * * See the GNU General Public License for more details. */ #include #include #include #include #include #include /** * llc_sap_action_unit_data_ind - forward UI PDU to network layer * @sap: SAP * @skb: the event to forward * * Received a UI PDU from MAC layer; forward to network layer as a * UNITDATA INDICATION; verify our event is the kind we expect */ int llc_sap_action_unitdata_ind(struct llc_sap *sap, struct sk_buff *skb) { llc_sap_rtn_pdu(sap, skb); return 0; } /** * llc_sap_action_send_ui - sends UI PDU resp to UNITDATA REQ to MAC layer * @sap: SAP * @skb: the event to send * * Sends a UI PDU to the MAC layer in response to a UNITDATA REQUEST * primitive from the network layer. Verifies event is a primitive type of * event. Verify the primitive is a UNITDATA REQUEST. */ int llc_sap_action_send_ui(struct llc_sap *sap, struct sk_buff *skb) { struct llc_sap_state_ev *ev = llc_sap_ev(skb); int rc; llc_pdu_header_init(skb, LLC_PDU_TYPE_U, ev->saddr.lsap, ev->daddr.lsap, LLC_PDU_CMD); llc_pdu_init_as_ui_cmd(skb); rc = llc_mac_hdr_init(skb, ev->saddr.mac, ev->daddr.mac); if (likely(!rc)) rc = dev_queue_xmit(skb); return rc; } /** * llc_sap_action_send_xid_c - send XID PDU as response to XID REQ * @sap: SAP * @skb: the event to send * * Send a XID command PDU to MAC layer in response to a XID REQUEST * primitive from the network layer. Verify event is a primitive type * event. Verify the primitive is a XID REQUEST. */ int llc_sap_action_send_xid_c(struct llc_sap *sap, struct sk_buff *skb) { struct llc_sap_state_ev *ev = llc_sap_ev(skb); int rc; llc_pdu_header_init(skb, LLC_PDU_TYPE_U, ev->saddr.lsap, ev->daddr.lsap, LLC_PDU_CMD); llc_pdu_init_as_xid_cmd(skb, LLC_XID_NULL_CLASS_2, 0); rc = llc_mac_hdr_init(skb, ev->saddr.mac, ev->daddr.mac); if (likely(!rc)) rc = dev_queue_xmit(skb); return rc; } /** * llc_sap_action_send_xid_r - send XID PDU resp to MAC for received XID * @sap: SAP * @skb: the event to send * * Send XID response PDU to MAC in response to an earlier received XID * command PDU. Verify event is a PDU type event */ int llc_sap_action_send_xid_r(struct llc_sap *sap, struct sk_buff *skb) { u8 mac_da[ETH_ALEN], mac_sa[ETH_ALEN], dsap; int rc = 1; struct sk_buff *nskb; llc_pdu_decode_sa(skb, mac_da); llc_pdu_decode_da(skb, mac_sa); llc_pdu_decode_ssap(skb, &dsap); nskb = llc_alloc_frame(NULL, skb->dev, LLC_PDU_TYPE_U, sizeof(struct llc_xid_info)); if (!nskb) goto out; llc_pdu_header_init(nskb, LLC_PDU_TYPE_U, sap->laddr.lsap, dsap, LLC_PDU_RSP); llc_pdu_init_as_xid_rsp(nskb, LLC_XID_NULL_CLASS_2, 0); rc = llc_mac_hdr_init(nskb, mac_sa, mac_da); if (likely(!rc)) rc = dev_queue_xmit(nskb); out: return rc; } /** * llc_sap_action_send_test_c - send TEST PDU to MAC in resp to TEST REQ * @sap: SAP * @skb: the event to send * * Send a TEST command PDU to the MAC layer in response to a TEST REQUEST * primitive from the network layer. Verify event is a primitive type * event; verify the primitive is a TEST REQUEST. */ int llc_sap_action_send_test_c(struct llc_sap *sap, struct sk_buff *skb) { struct llc_sap_state_ev *ev = llc_sap_ev(skb); int rc; llc_pdu_header_init(skb, LLC_PDU_TYPE_U, ev->saddr.lsap, ev->daddr.lsap, LLC_PDU_CMD); llc_pdu_init_as_test_cmd(skb); rc = llc_mac_hdr_init(skb, ev->saddr.mac, ev->daddr.mac); if (likely(!rc)) rc = dev_queue_xmit(skb); return rc; } int llc_sap_action_send_test_r(struct llc_sap *sap, struct sk_buff *skb) { u8 mac_da[ETH_ALEN], mac_sa[ETH_ALEN], dsap; struct sk_buff *nskb; int rc = 1; u32 data_size; llc_pdu_decode_sa(skb, mac_da); llc_pdu_decode_da(skb, mac_sa); llc_pdu_decode_ssap(skb, &dsap); /* The test request command is type U (llc_len = 3) */ data_size = ntohs(eth_hdr(skb)->h_proto) - 3; nskb = llc_alloc_frame(NULL, skb->dev, LLC_PDU_TYPE_U, data_size); if (!nskb) goto out; llc_pdu_header_init(nskb, LLC_PDU_TYPE_U, sap->laddr.lsap, dsap, LLC_PDU_RSP); llc_pdu_init_as_test_rsp(nskb, skb); rc = llc_mac_hdr_init(nskb, mac_sa, mac_da); if (likely(!rc)) rc = dev_queue_xmit(nskb); out: return rc; } /** * llc_sap_action_report_status - report data link status to layer mgmt * @sap: SAP * @skb: the event to send * * Report data link status to layer management. Verify our event is the * kind we expect. */ int llc_sap_action_report_status(struct llc_sap *sap, struct sk_buff *skb) { return 0; } /** * llc_sap_action_xid_ind - send XID PDU resp to net layer via XID IND * @sap: SAP * @skb: the event to send * * Send a XID response PDU to the network layer via a XID INDICATION * primitive. */ int llc_sap_action_xid_ind(struct llc_sap *sap, struct sk_buff *skb) { llc_sap_rtn_pdu(sap, skb); return 0; } /** * llc_sap_action_test_ind - send TEST PDU to net layer via TEST IND * @sap: SAP * @skb: the event to send * * Send a TEST response PDU to the network layer via a TEST INDICATION * primitive. Verify our event is a PDU type event. */ int llc_sap_action_test_ind(struct llc_sap *sap, struct sk_buff *skb) { llc_sap_rtn_pdu(sap, skb); return 0; } n_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/dccp/Kconfig')