/* * For multichannel support */ #ifndef __SOUND_HDA_CHMAP_H #define __SOUND_HDA_CHMAP_H #include #include #define SND_PRINT_CHANNEL_ALLOCATION_ADVISED_BUFSIZE 80 struct hdac_cea_channel_speaker_allocation { int ca_index; int speakers[8]; /* derived values, just for convenience */ int channels; int spk_mask; }; struct hdac_chmap; struct hdac_chmap_ops { /* * Helpers for producing the channel map TLVs. These can be overridden * for devices that have non-standard mapping requirements. */ int (*chmap_cea_alloc_validate_get_type)(struct hdac_chmap *chmap, struct hdac_cea_channel_speaker_allocation *cap, int channels); void (*cea_alloc_to_tlv_chmap)(struct hdac_chmap *hchmap, struct hdac_cea_channel_speaker_allocation *cap, unsigned int *chmap, int channels); /* check that the user-given chmap is supported */ int (*chmap_validate)(struct hdac_chmap *hchmap, int ca, int channels, unsigned char *chmap); int (*get_spk_alloc)(struct hdac_device *hdac, int pcm_idx); void (*get_chmap)(struct hdac_device *hdac, int pcm_idx, unsigned char *chmap); void (*set_chmap)(struct hdac_device *hdac, int pcm_idx, unsigned char *chmap, int prepared); bool (*is_pcm_attached)(struct hdac_device *hdac, int pcm_idx); /* get and set channel assigned to each HDMI ASP (audio sample packet) slot */ int (*pin_get_slot_channel)(struct hdac_device *codec, hda_nid_t pin_nid, int asp_slot); int (*pin_set_slot_channel)(struct hdac_device *codec, hda_nid_t pin_nid, int asp_slot, int channel); void (*set_channel_count)(struct hdac_device *codec, hda_nid_t cvt_nid, int chs); }; struct hdac_chmap { unsigned int channels_max; /* max over all cvts */ struct hdac_chmap_ops ops; struct hdac_device *hdac; }; void snd_hdac_register_chmap_ops(struct hdac_device *hdac, struct hdac_chmap *chmap); int snd_hdac_channel_allocation(struct hdac_device *hdac, int spk_alloc, int channels, bool chmap_set, bool non_pcm, unsigned char *map); int snd_hdac_get_active_channels(int ca); void snd_hdac_setup_channel_mapping(struct hdac_chmap *chmap, hda_nid_t pin_nid, bool non_pcm, int ca, int channels, unsigned char *map, bool chmap_set); void snd_hdac_print_channel_allocation(int spk_alloc, char *buf, int buflen); struct hdac_cea_channel_speaker_allocation *snd_hdac_get_ch_alloc_from_ca(int ca); int snd_hdac_chmap_to_spk_mask(unsigned char c); int snd_hdac_spk_to_chmap(int spk); int snd_hdac_add_chmap_ctls(struct snd_pcm *pcm, int pcm_idx, struct hdac_chmap *chmap); #endif /* __SOUND_HDA_CHMAP_H */ ion>
path: root/net/irda/ircomm/ircomm_tty_attach.c
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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 /net/irda/ircomm/ircomm_tty_attach.c
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 'net/irda/ircomm/ircomm_tty_attach.c')