请教Unable to handle kernel paging request at virtual address 的问题

[ermuzi]

在开发板上运行串口（HDLC、485）通信程序， 板上有232调试口、485和422串口，还有HDLC通信口，开启top打印系统状态，程序运行一段时间之后（有时候是几小时有时几十小时就出问题）485通信就会死掉，232调试打印也不再输出，但HDLC通信还是正常的。有时跑连续运行7、8天也不会出问题。出问题的时候通过串口的打印可以看到如下的信息（最后几行是最后显示的top输出信息）：
Unable to handle kernel paging request at virtual address 439d9708
pgd = c3a30000
[439d9708] *pgd=00000000
Internal error: Oops: 5 [#1]
last sysfs file: /sys/devices/platform/leds-gpio/leds/tax_led/brightness
Modules linked in:
CPU: 0 Not tainted (2.6.38+ #278)
PC is at anon_vma_fork+0x60/0xcc
LR is at anon_vma_fork+0x50/0xcc
pc : [<c0086374>] lr : [<c0086364>] psr: a0000013
sp : c3a41e88 ip : c3a41e88 fp : c3a41eac
r10: c3a2a128 r9 : c3a2a2fc r8 : c030cef0
r7 : c39f9de0 r6 : 00000000 r5 : c3a2a128 r4 : c39d9648
r3 : c39a09f8 r2 : 439d9708 r1 : c39a0a00 r0 : c39a09f8
Flags: NzCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment user
Control: 0005317f Table: 23a30000 DAC: 00000015
Process tax_app (pid: 355, stack limit = 0xc3a40270)
Stack: (0xc3a41e88 to 0xc3a42000)
1e80: c3a2a160 c39d01e0 c39f9de0 c39d0960 00000001 c3a2a300
1ea0: c3a41ef4 c3a41eb0 c003947c c0086324 c3a40000 c3a40030 c3a2a2ec c39d0214
1ec0: c39d0994 c3a2a2e0 c381867c 00100011 c3818640 c381b3a0 c381b47c 00000000
1ee0: c3a40038 4142cc40 c3a41f44 c3a41ef8 c0039e78 c00392b0 00000000 00000000
1f00: c43c0002 c381b4f4 00000000 c3a41fb0 c3a40000 00000000 c3a41f64 00100011
1f20: c3a41fb0 00000000 00000000 4142cc40 00000000 00000000 c3a41f8c c3a41f48
1f40: c003a48c c0039708 00000001 00000000 00000000 4142cc64 00000008 00000000
1f60: 4142cc64 c01509a8 00000001 4142cce8 4142cc64 00000078 c002b068 c3a40000
1f80: c3a41fa4 c3a41f90 c002e518 c003a340 4142cc40 00000001 00000000 c3a41fa8
1fa0: c002aec0 c002e4f4 00000001 c3a41fb0 00100011 00000000 4142cc40 00000002
1fc0: 00000001 4142cce8 4142cc64 00000078 00000001 0000a038 40247000 4142cdec
1fe0: 00000020 4142cc40 400f94c8 401471d8 00000010 00100011 00000000 00000000
Backtrace:
[<c0086314>] (anon_vma_fork+0x0/0xcc) from [<c003947c>] (dup_mm+0x1dc/0x410)
r8:c3a2a300 r7:00000001 r6:c39d0960 r5:c39f9de0 r4:c39d01e0
r3:c3a2a160
[<c00392a0>] (dup_mm+0x0/0x410) from [<c0039e78>] (copy_process.part.60+0x780/0xc04)
[<c00396f8>] (copy_process.part.60+0x0/0xc04) from [<c003a48c>] (do_fork+0x15c/0x2e8)
[<c003a330>] (do_fork+0x0/0x2e8) from [<c002e518>] (sys_clone+0x34/0x3c)
r9:c3a40000 r8:c002b068 r7:00000078 r6:4142cc64 r5:4142cce8
r4:00000001
[<c002e4e4>] (sys_clone+0x0/0x3c) from [<c002aec0>] (ret_fast_syscall+0x0/0x2c)
Code: e2503000 0a000014 e5972040 e2831008 (e5922000)
---[ end trace ca839e88ba593de6 ]---

Mem: 5720K used, 56120K free, 0K shrd, 0K buff, 2676K cached
CPU: 5% usr 21% sys 0% nic 72% idle 0% io 0% irq 0% sirq
Load average: 1.74 1.59 1.60 1/37 4564

搞不懂是应用的问题，还是硬件底层驱动的问题。
请教各路大神支招，感谢。