#ifndef USBUSX2Y_H
#define USBUSX2Y_H
#include "../usbaudio.h"
#include "../midi.h"
#include "usbus428ctldefs.h"
#define NRURBS 2
#define URBS_AsyncSeq 10
#define URB_DataLen_AsyncSeq 32
struct snd_usX2Y_AsyncSeq {
struct urb *urb[URBS_AsyncSeq];
char *buffer;
};
struct snd_usX2Y_urbSeq {
int submitted;
int len;
struct urb *urb[0];
};
#include "usx2yhwdeppcm.h"
struct usX2Ydev {
struct usb_device *dev;
int card_index;
int stride;
struct urb *In04urb;
void *In04Buf;
char In04Last[24];
unsigned In04IntCalls;
struct snd_usX2Y_urbSeq *US04;
wait_queue_head_t In04WaitQueue;
struct snd_usX2Y_AsyncSeq AS04;
unsigned int rate,
format;
int chip_status;
struct mutex pcm_mutex;
struct us428ctls_sharedmem *us428ctls_sharedmem;
int wait_iso_frame;
wait_queue_head_t us428ctls_wait_queue_head;
struct snd_usX2Y_hwdep_pcm_shm *hwdep_pcm_shm;
struct snd_usX2Y_substream *subs[4];
struct snd_usX2Y_substream * volatile prepare_subs;
wait_queue_head_t prepare_wait_queue;
struct list_head midi_list;
struct list_head pcm_list;
int pcm_devs;
};
struct snd_usX2Y_substream {
struct usX2Ydev *usX2Y;
struct snd_pcm_substream *pcm_substream;
int endpoint;
unsigned int maxpacksize; /* max packet size in bytes */
atomic_t state;
#define state_STOPPED 0
#define state_STARTING1 1
#define state_STARTING2 2
#define state_STARTING3 3
#define state_PREPARED 4
#define state_PRERUNNING 6
#define state_RUNNING 8
int hwptr; /* free frame position in the buffer (only for playback) */
int hwptr_done; /* processed frame position in the buffer */
int transfer_done; /* processed frames since last period update */
struct urb *urb[NRURBS]; /* data urb table */
struct urb *completed_urb;
char *tmpbuf; /* temporary buffer for playback */
};
#define usX2Y(c) ((struct usX2Ydev *)(c)->private_data)
int usX2Y_audio_create(struct snd_card *card);
int usX2Y_AsyncSeq04_init(struct usX2Ydev *usX2Y);
int usX2Y_In04_init(struct usX2Ydev *usX2Y);
#define NAME_ALLCAPS "US-X2Y"
#endif
et-next.git/diff/tools/perf/arch/xtensa/Build?id=966d2b04e070bc040319aaebfec09e0144dc3341'>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+