Hi, Sometimes I received the below error message when reboot the ast2500(With the latest kernel version). Does anyone have the similar issue? How to narrow down such problem? [ 472.770000] Unable to handle kernel NULL pointer dereference at virtual address 00000000 [ 472.770000] pgd = 80004000 [ 472.770000] [00000000] *pgd=00000000 [ 472.770000] Internal error: Oops: 80000007 [#1] ARM [ 472.770000] CPU: 0 PID: 946 Comm: klogd Not tainted 4.10.17-7422acad49264653b7895c252806a8074e1029c7 #2 [ 472.770000] Hardware name: ASpeed SoC [ 472.770000] task: 9d1cb000 task.stack: 9d40a000 [ 472.770000] PC is at 0x0 [ 472.770000] LR is at __wake_up_common+0x60/0x9c [ 472.770000] pc : [<00000000>] lr : [<80040e0c>] psr: 20000093 [ 472.770000] sp : 9d40bd00 ip : 9d0bfff4 fp : 9d40bd34 [ 472.770000] r10: 00000001 r9 : 00000000 r8 : 00000000 [ 472.770000] r7 : 9d4ab8e0 r6 : 00000000 r5 : 00000000 r4 : fffffff4 [ 472.770000] r3 : 00000000 r2 : 00000000 r1 : 00000001 r0 : 9d0bfff4 [ 472.770000] Flags: nzCv IRQs off FIQs on Mode SVC_32 ISA ARM Segment user [ 472.770000] Control: 00c5387d Table: 9cb28008 DAC: 00000055 [ 472.770000] Process klogd (pid: 946, stack limit = 0x9d40a188) [ 472.770000] Stack: (0x9d40bd00 to 0x9d40c000) [ 472.770000] bd00: 800e01d8 00000000 9d40bd2c 20000013 9d1a8900 00000001 9d1a8990 9d40bd68 [ 472.770000] bd20: 9d1a8990 00000008 9d40bd54 9d40bd38 800410b8 80040db8 00000000 9d40bd48 [ 472.770000] bd40: 800410b8 9d1a86c0 9d40bd64 9d40bd58 80337934 80041094 9d40bd94 9d40bd68 [ 472.770000] bd60: 803d0394 80337904 00000000 00000000 9e37a2e0 9e37a300 9e3ab048 9e41e570 [ 472.770000] bd80: 00000000 9e37a300 9d40bdac 9d40bd98 803d0438 803d01d0 9e37a2e0 9e37a300 [ 472.770000] bda0: 9d40bdc4 9d40bdb0 80335388 803d0418 9c9facc0 9e37a300 9d40bdd4 9d40bdc8 [ 472.770000] bdc0: 80335418 80335368 9d40be14 9d40bdd8 800e810c 80335408 00000000 00000000 [ 472.770000] bde0: 9e4bb980 9c9facc8 9d12d040 9d1cb2e0 9d1cb000 00000000 80659e80 9c9faa40 [ 472.770000] be00: 9d12d074 00010600 9d40be24 9d40be18 800e82a4 800e8084 9d40be4c 9d40be28 [ 472.770000] be20: 80031f2c 800e8298 9d1cb000 00000000 ffffe000 9d12d040 00000000 9d12d074 [ 472.770000] be40: 9d40be6c 9d40be50 8001b398 80031ebc 0000000f 00000000 9d40beac 0000000f [ 472.770000] be60: 9d40be84 9d40be70 8001ba9c 8001b124 00000000 4b24ca30 9d40bec4 9d40be88 [ 472.770000] be80: 800254f0 8001ba5c 9d40bec8 9d1f4ac0 9ca2f540 9d40a000 9d40a000 9d40bfb0 [ 472.770000] bea0: 4b24ca30 9d40bec8 00000000 4b24ca34 9d40a000 00000000 9d40bf8c 9d40bec8 [ 472.770000] bec0: 8000ccf0 800252e8 9d40bef4 9d40bed8 80024954 80024870 9d40a000 0000000f [ 472.770000] bee0: 00000000 fffffffa 000003b2 00000000 00000000 00000000 00000000 00000000 [ 472.770000] bf00: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 [ 472.770000] bf20: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 [ 472.770000] bf40: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 80025a30 [ 472.770000] bf60: 00000000 9d40a000 8000a6e4 9d40bfb0 000000af 8000a6e4 9d40a000 00000000 [ 472.770000] bf80: 9d40bfac 9d40bf90 8000d1d4 8000cc28 00000000 7ed07b90 000aed68 000000af [ 472.770000] bfa0: 00000000 9d40bfb0 8000a58c 8000d134 00000000 7ed07b90 00000000 00000008 [ 472.770000] bfc0: 00000000 7ed07b90 000aed68 000000af 0000000a 00000000 000b0d70 0000000f [ 472.770000] bfe0: 00000020 7ed07b90 ffffffff 4b24ca34 00000010 00000002 00000000 00000000 [ 472.770000] [<80040e0c>] (__wake_up_common) from [<800410b8>] (__wake_up+0x30/0x3c) [ 472.770000] [<800410b8>] (__wake_up) from [<80337934>] (sock_def_wakeup+0x3c/0x40) [ 472.770000] [<80337934>] (sock_def_wakeup) from [<803d0394>] (unix_release_sock+0x1d0/0x248) // 0x803378f8+0x1d0=0x80337AC8 [ 472.770000] [<803d0394>] (unix_release_sock) from [<803d0438>] (unix_release+0x2c/0x3c) [ 472.770000] [<803d0438>] (unix_release) from [<80335388>] (sock_release+0x2c/0xa0) [ 472.770000] [<80335388>] (sock_release) from [<80335418>] (sock_close+0x1c/0x24) [ 472.770000] [<80335418>] (sock_close) from [<800e810c>] (__fput+0x94/0x1c4) [ 472.770000] [<800e810c>] (__fput) from [<800e82a4>] (____fput+0x18/0x1c) [ 472.770000] [<800e82a4>] (____fput) from [<80031f2c>] (task_work_run+0x7c/0xa0) [ 472.770000] [<80031f2c>] (task_work_run) from [<8001b398>] (do_exit+0x280/0x8e8) [ 472.770000] [<8001b398>] (do_exit) from [<8001ba9c>] (do_group_exit+0x4c/0xb4) [ 472.770000] [<8001ba9c>] (do_group_exit) from [<800254f0>] (get_signal+0x214/0x580) [ 472.770000] [<800254f0>] (get_signal) from [<8000ccf0>] (do_signal+0xd4/0x3dc) [ 472.770000] [<8000ccf0>] (do_signal) from [<8000d1d4>] (do_work_pending+0xac/0xbc) [ 472.770000] [<8000d1d4>] (do_work_pending) from [<8000a58c>] (slow_work_pending+0xc/0x20) [ 472.770000] Code: bad PC value Thanks, Yong