/* * Apple Onboard Audio GPIO definitions * * Copyright 2006 Johannes Berg * * GPL v2, can be found in COPYING. */ #ifndef __AOA_GPIO_H #define __AOA_GPIO_H #include #include #include typedef void (*notify_func_t)(void *data); enum notify_type { AOA_NOTIFY_HEADPHONE, AOA_NOTIFY_LINE_IN, AOA_NOTIFY_LINE_OUT, }; struct gpio_runtime; struct gpio_methods { /* for initialisation/de-initialisation of the GPIO layer */ void (*init)(struct gpio_runtime *rt); void (*exit)(struct gpio_runtime *rt); /* turn off headphone, speakers, lineout */ void (*all_amps_off)(struct gpio_runtime *rt); /* turn headphone, speakers, lineout back to previous setting */ void (*all_amps_restore)(struct gpio_runtime *rt); void (*set_headphone)(struct gpio_runtime *rt, int on); void (*set_speakers)(struct gpio_runtime *rt, int on); void (*set_lineout)(struct gpio_runtime *rt, int on); void (*set_master)(struct gpio_runtime *rt, int on); int (*get_headphone)(struct gpio_runtime *rt); int (*get_speakers)(struct gpio_runtime *rt); int (*get_lineout)(struct gpio_runtime *rt); int (*get_master)(struct gpio_runtime *rt); void (*set_hw_reset)(struct gpio_runtime *rt, int on); /* use this to be notified of any events. The notification * function is passed the data, and is called in process * context by the use of schedule_work. * The interface for it is that setting a function to NULL * removes it, and they return 0 if the operation succeeded, * and -EBUSY if the notification is already assigned by * someone else. */ int (*set_notify)(struct gpio_runtime *rt, enum notify_type type, notify_func_t notify, void *data); /* returns 0 if not plugged in, 1 if plugged in * or a negative error code */ int (*get_detect)(struct gpio_runtime *rt, enum notify_type type); }; struct gpio_notification { struct delayed_work work; notify_func_t notify; void *data; void *gpio_private; struct mutex mutex; }; struct gpio_runtime { /* to be assigned by fabric */ struct device_node *node; /* since everyone needs this pointer anyway... */ struct gpio_methods *methods; /* to be used by the gpio implementation */ int implementation_private; struct gpio_notification headphone_notify; struct gpio_notification line_in_notify; struct gpio_notification line_out_notify; }; #endif /* __AOA_GPIO_H */ /sound/isa/galaxy/azt1605.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 /sound/isa/galaxy/azt1605.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 'sound/isa/galaxy/azt1605.c')