/********************************************************************* * * Filename: irmod.c * Version: 0.9 * Description: IrDA stack main entry points * Status: Experimental. * Author: Dag Brattli * Created at: Mon Dec 15 13:55:39 1997 * Modified at: Wed Jan 5 15:12:41 2000 * Modified by: Dag Brattli * * Copyright (c) 1997, 1999-2000 Dag Brattli, All Rights Reserved. * Copyright (c) 2000-2004 Jean Tourrilhes * * 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. * * Neither Dag Brattli nor University of Tromsø admit liability nor * provide warranty for any of this software. This material is * provided "AS-IS" and at no charge. * ********************************************************************/ /* * This file contains the main entry points of the IrDA stack. * They are in this file and not af_irda.c because some developpers * are using the IrDA stack without the socket API (compiling out * af_irda.c). * Jean II */ #include #include #include #include /* notify_t */ #include /* irlap_init */ #include /* irlmp_init */ #include /* iriap_init */ #include /* irttp_init */ #include /* irda_device_init */ /* Packet type handler. * Tell the kernel how IrDA packets should be handled. */ static struct packet_type irda_packet_type __read_mostly = { .type = cpu_to_be16(ETH_P_IRDA), .func = irlap_driver_rcv, /* Packet type handler irlap_frame.c */ }; /* * Function irda_notify_init (notify) * * Used for initializing the notify structure * */ void irda_notify_init(notify_t *notify) { notify->data_indication = NULL; notify->udata_indication = NULL; notify->connect_confirm = NULL; notify->connect_indication = NULL; notify->disconnect_indication = NULL; notify->flow_indication = NULL; notify->status_indication = NULL; notify->instance = NULL; strlcpy(notify->name, "Unknown", sizeof(notify->name)); } EXPORT_SYMBOL(irda_notify_init); /* * Function irda_init (void) * * Protocol stack initialisation entry point. * Initialise the various components of the IrDA stack */ static int __init irda_init(void) { int ret = 0; /* Lower layer of the stack */ irlmp_init(); irlap_init(); /* Driver/dongle support */ irda_device_init(); /* Higher layers of the stack */ iriap_init(); irttp_init(); ret = irsock_init(); if (ret < 0) goto out_err_1; /* Add IrDA packet type (Start receiving packets) */ dev_add_pack(&irda_packet_type); /* External APIs */ #ifdef CONFIG_PROC_FS irda_proc_register(); #endif #ifdef CONFIG_SYSCTL ret = irda_sysctl_register(); if (ret < 0) goto out_err_2; #endif ret = irda_nl_register(); if (ret < 0) goto out_err_3; return 0; out_err_3: #ifdef CONFIG_SYSCTL irda_sysctl_unregister(); out_err_2: #endif #ifdef CONFIG_PROC_FS irda_proc_unregister(); #endif /* Remove IrDA packet type (stop receiving packets) */ dev_remove_pack(&irda_packet_type); /* Remove higher layers */ irsock_cleanup(); out_err_1: irttp_cleanup(); iriap_cleanup(); /* Remove lower layers */ irda_device_cleanup(); irlap_cleanup(); /* Must be done before irlmp_cleanup()! DB */ /* Remove middle layer */ irlmp_cleanup(); return ret; } /* * Function irda_cleanup (void) * * Protocol stack cleanup/removal entry point. * Cleanup the various components of the IrDA stack */ static void __exit irda_cleanup(void) { /* Remove External APIs */ irda_nl_unregister(); #ifdef CONFIG_SYSCTL irda_sysctl_unregister(); #endif #ifdef CONFIG_PROC_FS irda_proc_unregister(); #endif /* Remove IrDA packet type (stop receiving packets) */ dev_remove_pack(&irda_packet_type); /* Remove higher layers */ irsock_cleanup(); irttp_cleanup(); iriap_cleanup(); /* Remove lower layers */ irda_device_cleanup(); irlap_cleanup(); /* Must be done before irlmp_cleanup()! DB */ /* Remove middle layer */ irlmp_cleanup(); } /* * The IrDA stack must be initialised *before* drivers get initialised, * and *before* higher protocols (IrLAN/IrCOMM/IrNET) get initialised, * otherwise bad things will happen (hashbins will be NULL for example). * Those modules are at module_init()/device_initcall() level. * * On the other hand, it needs to be initialised *after* the basic * networking, the /proc/net filesystem and sysctl module. Those are * currently initialised in .../init/main.c (before initcalls). * Also, IrDA drivers needs to be initialised *after* the random number * generator (main stack and higher layer init don't need it anymore). * * Jean II */ subsys_initcall(irda_init); module_exit(irda_cleanup); MODULE_AUTHOR("Dag Brattli & Jean Tourrilhes "); MODULE_DESCRIPTION("The Linux IrDA Protocol Stack"); MODULE_LICENSE("GPL"); MODULE_ALIAS_NETPROTO(PF_IRDA); h/include/xen/interface/nmi.h?id=39cb2c9a316e77f6dfba96c543e55b6672d5a37e'>patch) tree98fe974ee4e20121253de7f61fc8d01bdb3821c1 /include/xen/interface/nmi.h parent2c5d9555d6d937966d79d4c6529a5f7b9206e405 (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 'include/xen/interface/nmi.h')