/* * PC-Speaker driver for Linux * * Copyright (C) 1993-1997 Michael Beck * Copyright (C) 1997-2001 David Woodhouse * Copyright (C) 2001-2008 Stas Sergeev */ #ifndef __PCSP_H__ #define __PCSP_H__ #include #include #include #define PCSP_SOUND_VERSION 0x400 /* read 4.00 */ #define PCSP_DEBUG 0 /* default timer freq for PC-Speaker: 18643 Hz */ #define DIV_18KHZ 64 #define MAX_DIV DIV_18KHZ #define CALC_DIV(d) (MAX_DIV >> (d)) #define CUR_DIV() CALC_DIV(chip->treble) #define PCSP_MAX_TREBLE 1 /* unfortunately, with hrtimers 37KHz does not work very well :( */ #define PCSP_DEFAULT_TREBLE 0 #define MIN_DIV (MAX_DIV >> PCSP_MAX_TREBLE) /* wild guess */ #define PCSP_MIN_LPJ 1000000 #define PCSP_DEFAULT_SDIV (DIV_18KHZ >> 1) #define PCSP_DEFAULT_SRATE (PIT_TICK_RATE / PCSP_DEFAULT_SDIV) #define PCSP_INDEX_INC() (1 << (PCSP_MAX_TREBLE - chip->treble)) #define PCSP_CALC_RATE(i) (PIT_TICK_RATE / CALC_DIV(i)) #define PCSP_RATE() PCSP_CALC_RATE(chip->treble) #define PCSP_MIN_RATE__1 MAX_DIV/PIT_TICK_RATE #define PCSP_MAX_RATE__1 MIN_DIV/PIT_TICK_RATE #define PCSP_MAX_PERIOD_NS (1000000000ULL * PCSP_MIN_RATE__1) #define PCSP_MIN_PERIOD_NS (1000000000ULL * PCSP_MAX_RATE__1) #define PCSP_CALC_NS(div) ({ \ u64 __val = 1000000000ULL * (div); \ do_div(__val, PIT_TICK_RATE); \ __val; \ }) #define PCSP_PERIOD_NS() PCSP_CALC_NS(CUR_DIV()) #define PCSP_MAX_PERIOD_SIZE (64*1024) #define PCSP_MAX_PERIODS 512 #define PCSP_BUFFER_SIZE (128*1024) struct snd_pcsp { struct snd_card *card; struct snd_pcm *pcm; struct input_dev *input_dev; struct hrtimer timer; unsigned short port, irq, dma; spinlock_t substream_lock; struct snd_pcm_substream *playback_substream; unsigned int fmt_size; unsigned int is_signed; size_t playback_ptr; size_t period_ptr; atomic_t timer_active; int thalf; u64 ns_rem; unsigned char val61; int enable; int max_treble; int treble; int pcspkr; }; extern struct snd_pcsp pcsp_chip; extern enum hrtimer_restart pcsp_do_timer(struct hrtimer *handle); extern void pcsp_sync_stop(struct snd_pcsp *chip); extern int snd_pcsp_new_pcm(struct snd_pcsp *chip); extern int snd_pcsp_new_mixer(struct snd_pcsp *chip, int nopcm); #endif fda2d530d3b268eef542c5414e54bf1a'/>
path: root/fs/nfs/pnfs_nfs.c
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authorIago Abal <mail@iagoabal.eu>2017-01-11 14:00:21 +0100
committerVinod Koul <vinod.koul@intel.com>2017-01-25 15:35:11 +0530
commit91539eb1fda2d530d3b268eef542c5414e54bf1a (patch)
tree960f5ca6342ad20837aff18aad6e8ecd7da32fd6 /fs/nfs/pnfs_nfs.c
parent6610d0edf6dc7ee97e46ab3a538a565c79d26199 (diff)
dmaengine: pl330: fix double lock
The static bug finder EBA (http://www.iagoabal.eu/eba/) reported the following double-lock bug: Double lock: 1. spin_lock_irqsave(pch->lock, flags) at pl330_free_chan_resources:2236; 2. call to function `pl330_release_channel' immediately after; 3. call to function `dma_pl330_rqcb' in line 1753; 4. spin_lock_irqsave(pch->lock, flags) at dma_pl330_rqcb:1505. I have fixed it as suggested by Marek Szyprowski. First, I have replaced `pch->lock' with `pl330->lock' in functions `pl330_alloc_chan_resources' and `pl330_free_chan_resources'. This avoids the double-lock by acquiring a different lock than `dma_pl330_rqcb'. NOTE that, as a result, `pl330_free_chan_resources' executes `list_splice_tail_init' on `pch->work_list' under lock `pl330->lock', whereas in the rest of the code `pch->work_list' is protected by `pch->lock'. I don't know if this may cause race conditions. Similarly `pch->cyclic' is written by `pl330_alloc_chan_resources' under `pl330->lock' but read by `pl330_tx_submit' under `pch->lock'. Second, I have removed locking from `pl330_request_channel' and `pl330_release_channel' functions. Function `pl330_request_channel' is only called from `pl330_alloc_chan_resources', so the lock is already held. Function `pl330_release_channel' is called from `pl330_free_chan_resources', which already holds the lock, and from `pl330_del'. Function `pl330_del' is called in an error path of `pl330_probe' and at the end of `pl330_remove', but I assume that there cannot be concurrent accesses to the protected data at those points. Signed-off-by: Iago Abal <mail@iagoabal.eu> Reviewed-by: Marek Szyprowski <m.szyprowski@samsung.com> Signed-off-by: Vinod Koul <vinod.koul@intel.com>
Diffstat (limited to 'fs/nfs/pnfs_nfs.c')