/* * Copyright (C) 2000 Takashi Iwai * * Routines for control of EMU10K1 WaveTable synth * * 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. * * 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */ #include "emu10k1_synth_local.h" #include #include MODULE_AUTHOR("Takashi Iwai"); MODULE_DESCRIPTION("Routines for control of EMU10K1 WaveTable synth"); MODULE_LICENSE("GPL"); /* * create a new hardware dependent device for Emu10k1 */ static int snd_emu10k1_synth_probe(struct device *_dev) { struct snd_seq_device *dev = to_seq_dev(_dev); struct snd_emux *emux; struct snd_emu10k1 *hw; struct snd_emu10k1_synth_arg *arg; unsigned long flags; arg = SNDRV_SEQ_DEVICE_ARGPTR(dev); if (arg == NULL) return -EINVAL; if (arg->seq_ports <= 0) return 0; /* nothing */ if (arg->max_voices < 1) arg->max_voices = 1; else if (arg->max_voices > 64) arg->max_voices = 64; if (snd_emux_new(&emux) < 0) return -ENOMEM; snd_emu10k1_ops_setup(emux); hw = arg->hwptr; emux->hw = hw; emux->max_voices = arg->max_voices; emux->num_ports = arg->seq_ports; emux->pitch_shift = -501; emux->memhdr = hw->memhdr; /* maximum two ports */ emux->midi_ports = arg->seq_ports < 2 ? arg->seq_ports : 2; /* audigy has two external midis */ emux->midi_devidx = hw->audigy ? 2 : 1; emux->linear_panning = 0; emux->hwdep_idx = 2; /* FIXED */ if (snd_emux_register(emux, dev->card, arg->index, "Emu10k1") < 0) { snd_emux_free(emux); return -ENOMEM; } spin_lock_irqsave(&hw->voice_lock, flags); hw->synth = emux; hw->get_synth_voice = snd_emu10k1_synth_get_voice; spin_unlock_irqrestore(&hw->voice_lock, flags); dev->driver_data = emux; return 0; } static int snd_emu10k1_synth_remove(struct device *_dev) { struct snd_seq_device *dev = to_seq_dev(_dev); struct snd_emux *emux; struct snd_emu10k1 *hw; unsigned long flags; if (dev->driver_data == NULL) return 0; /* not registered actually */ emux = dev->driver_data; hw = emux->hw; spin_lock_irqsave(&hw->voice_lock, flags); hw->synth = NULL; hw->get_synth_voice = NULL; spin_unlock_irqrestore(&hw->voice_lock, flags); snd_emux_free(emux); return 0; } /* * INIT part */ static struct snd_seq_driver emu10k1_synth_driver = { .driver = { .name = KBUILD_MODNAME, .probe = snd_emu10k1_synth_probe, .remove = snd_emu10k1_synth_remove, }, .id = SNDRV_SEQ_DEV_ID_EMU10K1_SYNTH, .argsize = sizeof(struct snd_emu10k1_synth_arg), }; module_snd_seq_driver(emu10k1_synth_driver); ommit/tools/testing?id=966d2b04e070bc040319aaebfec09e0144dc3341'>testing/selftests/ftrace/test.d/00basic/basic3.tc
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authorDouglas Miller <dougmill@linux.vnet.ibm.com>2017-01-28 06:42:20 -0600
committerTejun Heo <tj@kernel.org>2017-01-28 07:49:42 -0500
commit966d2b04e070bc040319aaebfec09e0144dc3341 (patch)
tree4b96156e3d1dd4dfd6039b7c219c9dc4616da52d /tools/testing/selftests/ftrace/test.d/00basic/basic3.tc
parent1b1bc42c1692e9b62756323c675a44cb1a1f9dbd (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/selftests/ftrace/test.d/00basic/basic3.tc')