/* * Freescale MPC5200 Audio DMA driver */ #ifndef __SOUND_SOC_FSL_MPC5200_DMA_H__ #define __SOUND_SOC_FSL_MPC5200_DMA_H__ #define PSC_STREAM_NAME_LEN 32 /** * psc_ac97_stream - Data specific to a single stream (playback or capture) * @active: flag indicating if the stream is active * @psc_dma: pointer back to parent psc_dma data structure * @bcom_task: bestcomm task structure * @irq: irq number for bestcomm task * @period_end: physical address of end of DMA region * @period_next_pt: physical address of next DMA buffer to enqueue * @period_bytes: size of DMA period in bytes * @ac97_slot_bits: Enable bits for turning on the correct AC97 slot */ struct psc_dma_stream { struct snd_pcm_runtime *runtime; int active; struct psc_dma *psc_dma; struct bcom_task *bcom_task; int irq; struct snd_pcm_substream *stream; int period_next; int period_current; int period_bytes; int period_count; /* AC97 state */ u32 ac97_slot_bits; }; /** * psc_dma - Private driver data * @name: short name for this device ("PSC0", "PSC1", etc) * @psc_regs: pointer to the PSC's registers * @fifo_regs: pointer to the PSC's FIFO registers * @irq: IRQ of this PSC * @dev: struct device pointer * @dai: the CPU DAI for this device * @sicr: Base value used in serial interface control register; mode is ORed * with this value. * @playback: Playback stream context data * @capture: Capture stream context data */ struct psc_dma { char name[32]; struct mpc52xx_psc __iomem *psc_regs; struct mpc52xx_psc_fifo __iomem *fifo_regs; unsigned int irq; struct device *dev; spinlock_t lock; struct mutex mutex; u32 sicr; uint sysclk; int imr; int id; unsigned int slots; /* per-stream data */ struct psc_dma_stream playback; struct psc_dma_stream capture; /* Statistics */ struct { unsigned long overrun_count; unsigned long underrun_count; } stats; }; /* Utility for retrieving psc_dma_stream structure from a substream */ static inline struct psc_dma_stream * to_psc_dma_stream(struct snd_pcm_substream *substream, struct psc_dma *psc_dma) { if (substream->pstr->stream == SNDRV_PCM_STREAM_CAPTURE) return &psc_dma->capture; return &psc_dma->playback; } int mpc5200_audio_dma_create(struct platform_device *op); int mpc5200_audio_dma_destroy(struct platform_device *op); #endif /* __SOUND_SOC_FSL_MPC5200_DMA_H__ */ s='right' method='get' action='/cgit.cgi/linux/net-next.git/log/tools/testing/selftests/rcutorture/configs/rcu/TREE08'>
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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/rcutorture/configs/rcu/TREE08
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/rcutorture/configs/rcu/TREE08')