#ifndef _UAPICCISS_IOCTLH #define _UAPICCISS_IOCTLH #include #include #include #define CCISS_IOC_MAGIC 'B' typedef struct _cciss_pci_info_struct { unsigned char bus; unsigned char dev_fn; unsigned short domain; __u32 board_id; } cciss_pci_info_struct; typedef struct _cciss_coalint_struct { __u32 delay; __u32 count; } cciss_coalint_struct; typedef char NodeName_type[16]; typedef __u32 Heartbeat_type; #define CISS_PARSCSIU2 0x0001 #define CISS_PARCSCIU3 0x0002 #define CISS_FIBRE1G 0x0100 #define CISS_FIBRE2G 0x0200 typedef __u32 BusTypes_type; typedef char FirmwareVer_type[4]; typedef __u32 DriverVer_type; #define MAX_KMALLOC_SIZE 128000 typedef struct _IOCTL_Command_struct { LUNAddr_struct LUN_info; RequestBlock_struct Request; ErrorInfo_struct error_info; WORD buf_size; /* size in bytes of the buf */ BYTE __user *buf; } IOCTL_Command_struct; typedef struct _BIG_IOCTL_Command_struct { LUNAddr_struct LUN_info; RequestBlock_struct Request; ErrorInfo_struct error_info; DWORD malloc_size; /* < MAX_KMALLOC_SIZE in cciss.c */ DWORD buf_size; /* size in bytes of the buf */ /* < malloc_size * MAXSGENTRIES */ BYTE __user *buf; } BIG_IOCTL_Command_struct; typedef struct _LogvolInfo_struct{ __u32 LunID; int num_opens; /* number of opens on the logical volume */ int num_parts; /* number of partitions configured on logvol */ } LogvolInfo_struct; #define CCISS_GETPCIINFO _IOR(CCISS_IOC_MAGIC, 1, cciss_pci_info_struct) #define CCISS_GETINTINFO _IOR(CCISS_IOC_MAGIC, 2, cciss_coalint_struct) #define CCISS_SETINTINFO _IOW(CCISS_IOC_MAGIC, 3, cciss_coalint_struct) #define CCISS_GETNODENAME _IOR(CCISS_IOC_MAGIC, 4, NodeName_type) #define CCISS_SETNODENAME _IOW(CCISS_IOC_MAGIC, 5, NodeName_type) #define CCISS_GETHEARTBEAT _IOR(CCISS_IOC_MAGIC, 6, Heartbeat_type) #define CCISS_GETBUSTYPES _IOR(CCISS_IOC_MAGIC, 7, BusTypes_type) #define CCISS_GETFIRMVER _IOR(CCISS_IOC_MAGIC, 8, FirmwareVer_type) #define CCISS_GETDRIVVER _IOR(CCISS_IOC_MAGIC, 9, DriverVer_type) #define CCISS_REVALIDVOLS _IO(CCISS_IOC_MAGIC, 10) #define CCISS_PASSTHRU _IOWR(CCISS_IOC_MAGIC, 11, IOCTL_Command_struct) #define CCISS_DEREGDISK _IO(CCISS_IOC_MAGIC, 12) /* no longer used... use REGNEWD instead */ #define CCISS_REGNEWDISK _IOW(CCISS_IOC_MAGIC, 13, int) #define CCISS_REGNEWD _IO(CCISS_IOC_MAGIC, 14) #define CCISS_RESCANDISK _IO(CCISS_IOC_MAGIC, 16) #define CCISS_GETLUNINFO _IOR(CCISS_IOC_MAGIC, 17, LogvolInfo_struct) #define CCISS_BIG_PASSTHRU _IOWR(CCISS_IOC_MAGIC, 18, BIG_IOCTL_Command_struct) #endif /* _UAPICCISS_IOCTLH */ value='grep'>log msg
path: root/tools/perf/tests/backward-ring-buffer.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 /tools/perf/tests/backward-ring-buffer.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 'tools/perf/tests/backward-ring-buffer.c')