/* * USB Serial Converter Bus specific functions * * Copyright (C) 2002 Greg Kroah-Hartman (greg@kroah.com) * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License version * 2 as published by the Free Software Foundation. */ #include #include #include #include #include #include #include static int usb_serial_device_match(struct device *dev, struct device_driver *drv) { struct usb_serial_driver *driver; const struct usb_serial_port *port; /* * drivers are already assigned to ports in serial_probe so it's * a simple check here. */ port = to_usb_serial_port(dev); if (!port) return 0; driver = to_usb_serial_driver(drv); if (driver == port->serial->type) return 1; return 0; } static int usb_serial_device_probe(struct device *dev) { struct usb_serial_driver *driver; struct usb_serial_port *port; struct device *tty_dev; int retval = 0; int minor; port = to_usb_serial_port(dev); if (!port) return -ENODEV; /* make sure suspend/resume doesn't race against port_probe */ retval = usb_autopm_get_interface(port->serial->interface); if (retval) return retval; driver = port->serial->type; if (driver->port_probe) { retval = driver->port_probe(port); if (retval) goto err_autopm_put; } minor = port->minor; tty_dev = tty_register_device(usb_serial_tty_driver, minor, dev); if (IS_ERR(tty_dev)) { retval = PTR_ERR(tty_dev); goto err_port_remove; } usb_autopm_put_interface(port->serial->interface); dev_info(&port->serial->dev->dev, "%s converter now attached to ttyUSB%d\n", driver->description, minor); return 0; err_port_remove: if (driver->port_remove) driver->port_remove(port); err_autopm_put: usb_autopm_put_interface(port->serial->interface); return retval; } static int usb_serial_device_remove(struct device *dev) { struct usb_serial_driver *driver; struct usb_serial_port *port; int retval = 0; int minor; int autopm_err; port = to_usb_serial_port(dev); if (!port) return -ENODEV; /* * Make sure suspend/resume doesn't race against port_remove. * * Note that no further runtime PM callbacks will be made if * autopm_get fails. */ autopm_err = usb_autopm_get_interface(port->serial->interface); minor = port->minor; tty_unregister_device(usb_serial_tty_driver, minor); driver = port->serial->type; if (driver->port_remove) retval = driver->port_remove(port); dev_info(dev, "%s converter now disconnected from ttyUSB%d\n", driver->description, minor); if (!autopm_err) usb_autopm_put_interface(port->serial->interface); return retval; } static ssize_t new_id_store(struct device_driver *driver, const char *buf, size_t count) { struct usb_serial_driver *usb_drv = to_usb_serial_driver(driver); ssize_t retval = usb_store_new_id(&usb_drv->dynids, usb_drv->id_table, driver, buf, count); if (retval >= 0 && usb_drv->usb_driver != NULL) retval = usb_store_new_id(&usb_drv->usb_driver->dynids, usb_drv->usb_driver->id_table, &usb_drv->usb_driver->drvwrap.driver, buf, count); return retval; } static ssize_t new_id_show(struct device_driver *driver, char *buf) { struct usb_serial_driver *usb_drv = to_usb_serial_driver(driver); return usb_show_dynids(&usb_drv->dynids, buf); } static DRIVER_ATTR_RW(new_id); static struct attribute *usb_serial_drv_attrs[] = { &driver_attr_new_id.attr, NULL, }; ATTRIBUTE_GROUPS(usb_serial_drv); static void free_dynids(struct usb_serial_driver *drv) { struct usb_dynid *dynid, *n; spin_lock(&drv->dynids.lock); list_for_each_entry_safe(dynid, n, &drv->dynids.list, node) { list_del(&dynid->node); kfree(dynid); } spin_unlock(&drv->dynids.lock); } struct bus_type usb_serial_bus_type = { .name = "usb-serial", .match = usb_serial_device_match, .probe = usb_serial_device_probe, .remove = usb_serial_device_remove, .drv_groups = usb_serial_drv_groups, }; int usb_serial_bus_register(struct usb_serial_driver *driver) { int retval; driver->driver.bus = &usb_serial_bus_type; spin_lock_init(&driver->dynids.lock); INIT_LIST_HEAD(&driver->dynids.list); retval = driver_register(&driver->driver); return retval; } void usb_serial_bus_deregister(struct usb_serial_driver *driver) { free_dynids(driver); driver_unregister(&driver->driver); } ='label'>mode:
authorLinus Torvalds <torvalds@linux-foundation.org>2017-01-29 13:50:06 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2017-01-29 13:50:06 -0800
commit39cb2c9a316e77f6dfba96c543e55b6672d5a37e (patch)
tree98fe974ee4e20121253de7f61fc8d01bdb3821c1 /sound/usb/6fire
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 'sound/usb/6fire')