/* * Linux driver for TerraTec DMX 6Fire USB * * Main routines and module definitions. * * Author: Torsten Schenk * Created: Jan 01, 2011 * Copyright: (C) Torsten Schenk * * 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 "chip.h" #include "firmware.h" #include "pcm.h" #include "control.h" #include "comm.h" #include "midi.h" #include #include #include #include #include #include MODULE_AUTHOR("Torsten Schenk "); MODULE_DESCRIPTION("TerraTec DMX 6Fire USB audio driver"); MODULE_LICENSE("GPL v2"); MODULE_SUPPORTED_DEVICE("{{TerraTec,DMX 6Fire USB}}"); static int index[SNDRV_CARDS] = SNDRV_DEFAULT_IDX; /* Index 0-max */ static char *id[SNDRV_CARDS] = SNDRV_DEFAULT_STR; /* Id for card */ static bool enable[SNDRV_CARDS] = SNDRV_DEFAULT_ENABLE_PNP; /* Enable card */ static struct sfire_chip *chips[SNDRV_CARDS] = SNDRV_DEFAULT_PTR; static struct usb_device *devices[SNDRV_CARDS] = SNDRV_DEFAULT_PTR; module_param_array(index, int, NULL, 0444); MODULE_PARM_DESC(index, "Index value for the 6fire sound device"); module_param_array(id, charp, NULL, 0444); MODULE_PARM_DESC(id, "ID string for the 6fire sound device."); module_param_array(enable, bool, NULL, 0444); MODULE_PARM_DESC(enable, "Enable the 6fire sound device."); static DEFINE_MUTEX(register_mutex); static void usb6fire_chip_abort(struct sfire_chip *chip) { if (chip) { if (chip->pcm) usb6fire_pcm_abort(chip); if (chip->midi) usb6fire_midi_abort(chip); if (chip->comm) usb6fire_comm_abort(chip); if (chip->control) usb6fire_control_abort(chip); if (chip->card) { snd_card_disconnect(chip->card); snd_card_free_when_closed(chip->card); chip->card = NULL; } } } static void usb6fire_chip_destroy(struct sfire_chip *chip) { if (chip) { if (chip->pcm) usb6fire_pcm_destroy(chip); if (chip->midi) usb6fire_midi_destroy(chip); if (chip->comm) usb6fire_comm_destroy(chip); if (chip->control) usb6fire_control_destroy(chip); if (chip->card) snd_card_free(chip->card); } } static int usb6fire_chip_probe(struct usb_interface *intf, const struct usb_device_id *usb_id) { int ret; int i; struct sfire_chip *chip = NULL; struct usb_device *device = interface_to_usbdev(intf); int regidx = -1; /* index in module parameter array */ struct snd_card *card = NULL; /* look if we already serve this card and return if so */ mutex_lock(®ister_mutex); for (i = 0; i < SNDRV_CARDS; i++) { if (devices[i] == device) { if (chips[i]) chips[i]->intf_count++; usb_set_intfdata(intf, chips[i]); mutex_unlock(®ister_mutex); return 0; } else if (!devices[i] && regidx < 0) regidx = i; } if (regidx < 0) { mutex_unlock(®ister_mutex); dev_err(&intf->dev, "too many cards registered.\n"); return -ENODEV; } devices[regidx] = device; mutex_unlock(®ister_mutex); /* check, if firmware is present on device, upload it if not */ ret = usb6fire_fw_init(intf); if (ret < 0) return ret; else if (ret == FW_NOT_READY) /* firmware update performed */ return 0; /* if we are here, card can be registered in alsa. */ if (usb_set_interface(device, 0, 0) != 0) { dev_err(&intf->dev, "can't set first interface.\n"); return -EIO; } ret = snd_card_new(&intf->dev, index[regidx], id[regidx], THIS_MODULE, sizeof(struct sfire_chip), &card); if (ret < 0) { dev_err(&intf->dev, "cannot create alsa card.\n"); return ret; } strcpy(card->driver, "6FireUSB"); strcpy(card->shortname, "TerraTec DMX6FireUSB"); sprintf(card->longname, "%s at %d:%d", card->shortname, device->bus->busnum, device->devnum); chip = card->private_data; chips[regidx] = chip; chip->dev = device; chip->regidx = regidx; chip->intf_count = 1; chip->card = card; ret = usb6fire_comm_init(chip); if (ret < 0) { usb6fire_chip_destroy(chip); return ret; } ret = usb6fire_midi_init(chip); if (ret < 0) { usb6fire_chip_destroy(chip); return ret; } ret = usb6fire_pcm_init(chip); if (ret < 0) { usb6fire_chip_destroy(chip); return ret; } ret = usb6fire_control_init(chip); if (ret < 0) { usb6fire_chip_destroy(chip); return ret; } ret = snd_card_register(card); if (ret < 0) { dev_err(&intf->dev, "cannot register card."); usb6fire_chip_destroy(chip); return ret; } usb_set_intfdata(intf, chip); return 0; } static void usb6fire_chip_disconnect(struct usb_interface *intf) { struct sfire_chip *chip; struct snd_card *card; chip = usb_get_intfdata(intf); if (chip) { /* if !chip, fw upload has been performed */ card = chip->card; chip->intf_count--; if (!chip->intf_count) { mutex_lock(®ister_mutex); devices[chip->regidx] = NULL; chips[chip->regidx] = NULL; mutex_unlock(®ister_mutex); chip->shutdown = true; usb6fire_chip_abort(chip); usb6fire_chip_destroy(chip); } } } static struct usb_device_id device_table[] = { { .match_flags = USB_DEVICE_ID_MATCH_DEVICE, .idVendor = 0x0ccd, .idProduct = 0x0080 }, {} }; MODULE_DEVICE_TABLE(usb, device_table); static struct usb_driver usb_driver = { .name = "snd-usb-6fire", .probe = usb6fire_chip_probe, .disconnect = usb6fire_chip_disconnect, .id_table = device_table, }; module_usb_driver(usb_driver); ols/testing/radix-tree?id=1b1bc42c1692e9b62756323c675a44cb1a1f9dbd'>1b1bc42c1692e9b62756323c675a44cb1a1f9dbd (diff)
percpu-refcount: fix reference leak during percpu-atomic transition
percpu_ref_tryget() and percpu_ref_tryget_live() should return "true" IFF they acquire a reference. But the return value from atomic_long_inc_not_zero() is a long and may have high bits set, e.g. PERCPU_COUNT_BIAS, and the return value of the tryget routines is bool so the reference may actually be acquired but the routines return "false" which results in a reference leak since the caller assumes it does not need to do a corresponding percpu_ref_put(). This was seen when performing CPU hotplug during I/O, as hangs in blk_mq_freeze_queue_wait where percpu_ref_kill (blk_mq_freeze_queue_start) raced with percpu_ref_tryget (blk_mq_timeout_work). Sample stack trace: __switch_to+0x2c0/0x450 __schedule+0x2f8/0x970 schedule+0x48/0xc0 blk_mq_freeze_queue_wait+0x94/0x120 blk_mq_queue_reinit_work+0xb8/0x180 blk_mq_queue_reinit_prepare+0x84/0xa0 cpuhp_invoke_callback+0x17c/0x600 cpuhp_up_callbacks+0x58/0x150 _cpu_up+0xf0/0x1c0 do_cpu_up+0x120/0x150 cpu_subsys_online+0x64/0xe0 device_online+0xb4/0x120 online_store+0xb4/0xc0 dev_attr_store+0x68/0xa0 sysfs_kf_write+0x80/0xb0 kernfs_fop_write+0x17c/0x250 __vfs_write+0x6c/0x1e0 vfs_write+0xd0/0x270 SyS_write+0x6c/0x110 system_call+0x38/0xe0 Examination of the queue showed a single reference (no PERCPU_COUNT_BIAS, and __PERCPU_REF_DEAD, __PERCPU_REF_ATOMIC set) and no requests. However, conditions at the time of the race are count of PERCPU_COUNT_BIAS + 0 and __PERCPU_REF_DEAD and __PERCPU_REF_ATOMIC set. The fix is to make the tryget routines use an actual boolean internally instead of the atomic long result truncated to a int. Fixes: e625305b3907 percpu-refcount: make percpu_ref based on longs instead of ints Link: https://bugzilla.kernel.org/show_bug.cgi?id=190751 Signed-off-by: Douglas Miller <dougmill@linux.vnet.ibm.com> Reviewed-by: Jens Axboe <axboe@fb.com> Signed-off-by: Tejun Heo <tj@kernel.org> Fixes: e625305b3907 ("percpu-refcount: make percpu_ref based on longs instead of ints") Cc: stable@vger.kernel.org # v3.18+
Diffstat (limited to 'tools/testing/radix-tree')