opps kio

Unable to handle kernel NULL pointer dereference at virtual address 00000008
pgd = c7090000, hw pgd = c7090000
[00000008] *pgd=27096831, *pte=00000000, *ppte=00000000
Internal error: Oops: 17 [#4] ARM
Modules linked in: usb_f_ecm g_ether usb_f_rndis u_ether libcomposite option usb_wwan
CPU: 0 PID: 635 Comm: a5_test Tainted: G      D      3.14.17 #60
task: c7076140 ti: c7050000 task.ti: c7050000
PC is at gpio_read+0x18/0x110
LR is at vfs_read+0x9c/0x124
pc : [<c01b0738>]    lr : [<c00bb0b4>]    psr: a0000013
sp : c7051f48  ip : c01b0720  fp : 00000000
r10: be8decf4  r9 : c7050000  r8 : 00000045
r7 : c7051f80  r6 : 00000045  r5 : be8decf4  r4 : c79bbac0
r3 : 00000000  r2 : 00000045  r1 : be8decf4  r0 : c0417797
Flags: NzCv  IRQs on  FIQs on  Mode SVC_32  ISA ARM  Segment user
Control: 0005317f  Table: 27090000  DAC: 00000015
Process a5_test (pid: 635, stack limit = 0xc70501c8)
Stack: (0xc7051f48 to 0xc7052000)
1f40:                   c7b64da0 00000045 be8decf4 c00bb0b4 c7b64da0 be8decf4
1f60: 00000045 00000000 00000000 c7b64da0 c7b64da0 00000045 be8decf4 c00bb294
1f80: 00000000 00000000 00000045 00000005 00010b1c 00000000 00000003 c0009788
1fa0: 00000000 c00095c0 00000005 00010b1c 00000003 be8decf4 00000045 00010b44
1fc0: 00000005 00010b1c 00000000 00000003 00000000 00000000 b6f83000 00000000
1fe0: 00000000 be8decec 0000883c b6ea53bc 60000010 00000003 00000000 00000000
[<c01b0738>] (gpio_read) from [<c00bb0b4>] (vfs_read+0x9c/0x124)
[<c00bb0b4>] (vfs_read) from [<c00bb294>] (SyS_read+0x3c/0x78)
[<c00bb294>] (SyS_read) from [<c00095c0>] (ret_fast_syscall+0x0/0x2c)
Code: e5904078 e1a05001 e1a06002 e59f00e4 (e5d32008)
---[ end trace ecc5b8f97467efa3 ]---