本人使用的是ARM linux的一块开发板，之前移植过一个USB转RJ45（USB有线网卡）的驱动，并可以成功运行，但是后来因为要用到网桥，所以重新编译了内核，把802.1d Ethernet Bridging 模块编进去了，但是之后在板子上的linux里，加载我的USB网卡驱动是没问题，但是配置那个网卡时就出错了，错误信息如下：

[root@FriendlyARM plg]# ifconfig eth1 10.0.0.1
eth1: rxqlen 0 --> 4
Unable to handle kernel NULL pointer dereference at virtual address 000000f2
pgd = c3ab4000
[000000f2] *pgd=33afd031, *pte=00000000, *ppte=00000000
Internal error: Oops: 17 [#1]
last sysfs file: /sys/devices/platform/s3c2410-ohci/usb1/1-1/dev
Modules linked in: asix
CPU: 0    Not tainted  (2.6.32.2-FriendlyARM #14)
PC is at eth_type_trans+0x2c/0x11c
LR is at 0xf2
pc : []    lr : []    psr: 20000013
sp : c3af9bb8  ip : c3afe9c0  fp : c3af9bd4
r10: 00000052  r9 : c3ace2c0  r8 : c3afe300
r7 : c3ae5006  r6 : c3afe9c0  r5 : c3ace2c0  r4 : c3ace000
r3 : 000000f2  r2 : 00000000  r1 : 0000000e  r0 : 00000100
Flags: nzCv  IRQs on  FIQs on  Mode SVC_32  ISA ARM  Segment user
Control: c000717f  Table: 33ab4000  DAC: 00000015
Process ifconfig (pid: 745, stack limit = 0xc3af8270)
Stack: (0xc3af9bb8 to 0xc3afa000)
9ba0:                                                       c3afe9c0 c3ace2c0
9bc0: 00000052 c3ae5006 c3af9bec c3af9bd8 bf000398 c030858c c3ae5006 c3afe9c0
9be0: c3af9c24 c3af9bf0 bf0006a4 bf000380 c3af9cd8 ffad0052 c3af9c24 c3afe300
9c00: c3ace2c0 c3ace3c0 00000005 c3af8000 0000000a c0535220 c3af9c4c c3af9c28
9c20: bf007688 bf000648 00000000 c04d96a8 c0535220 00000000 c3af8000 0000000a
9c40: c3af9c6c c3af9c50 c004efa0 bf0075c8 00000018 00000001 00000100 00000006
9c60: c3af9ca4 c3af9c70 c004f634 c004ef38 c04dbe9c c3911240 0000002a 0000002a
9c80: c04e832c 00000000 c3ac8080 00000162 c3af9d88 c34084d8 c3af9cb4 c3af9ca8
9ca0: c004f70c c004f5b4 c3af9cd4 c3af9cb8 c0030048 c004f6d4 ffffffff f4000000
9cc0: 04000000 c3ac8080 c3af9d34 c3af9cd8 c0030b04 c0030010 c34084dc 00000162
9ce0: 00000000 001d9527 c34084dc 00000162 c3ab4000 c3ac8080 00000162 c3af9d88
9d00: c34084d8 c3af9d34 c3af9d38 c3af9d20 c0075c5c c014d4b4 80000013 ffffffff
9d20: 00000000 c3aafe70 c3af9d74 c3af9d38 c007679c c0075c4c c3af9d6c c3af9d48
9d40: c3408440 c01e3744 c3ac7e80 00000000 c3aa1d80 c3ab4000 c3aafe70 c3af9d88
9d60: 00000000 0016a000 c3af9dc4 c3af9d78 c0089484 c0076740 c3ab4000 c3ace000
9d80: 00000001 00000000 00000000 00000162 0016a000 00000000 c3af9dd4 00000000
9da0: c3ab4000 c3ab4000 c3af8000 0000016a 00000000 00000000 c3af9e2c c3af9dc8
9dc0: c0089f08 c008943c 00000162 00000000 00000000 c03a4694 c3af9e1c 0016a000
9de0: c3aafe70 c3aa1d80 000005a8 c3af9de8 c02f6dc8 00000000 00000000 bef4ac68
9e00: c0542270 c3aafe70 c3aa1d80 0016a97c c3aca300 c3aa1db4 80000005 c3af9fb0
9e20: c3af9edc c3af9e30 c0037ae8 c0089e14 c3af9e70 bef4ac68 00000020 c3af9e68
9e40: 00008913 c02fb86c c394f400 c394f40c c3ace000 00000000 31687465 00000000
9e60: 00000000 00000000 00001043 0100000a 00000001 001c6e20 00001043 0100000a
9e80: 00000001 001c6e20 00000001 00008914 bef4ac68 bef4ac68 bef4ac68 c00310c8
9ea0: c3af8000 00000000 c3af9ec4 c3af9eb8 c0341e94 c04d6818 001e762c 00000005
9ec0: c04d6868 c3af9fb0 00000003 0016a97c c3af9efc c3af9ee0 c0037c64 c0037954
9ee0: c04d6818 001e762c 00000005 c04d6868 c3af9fac c3af9f00 c00301e8 c0037bfc
9f00: c00aa78c c00aa17c c3af9f5c c3af9f18 c02e8cc4 c009eaa4 c03fec88 c3af9f28
9f20: c009ebf8 00000000 00000000 c0478064 c348a780 00000000 00000003 c348a780
9f40: 00000119 c00310c8 c3af8000 00000000 c3af9f84 00000003 bef4ac68 00008914
9f60: c3ac8100 c00310c8 c3af8000 00000000 c3af9fa4 c3af9f80 c00aaa48 c00aa464
9f80: c02e9b20 00000000 ffffffff 001e762c 000e8198 00000000 00000000 00000000
9fa0: 00000000 c3af9fb0 c0030ea4 c00301b8 00000000 00000000 001e7628 0016a97c
9fc0: 00000002 001e762c 000e8198 00000000 00000000 00000003 00000000 bef4ae74
9fe0: 000e8198 bef4acd8 000e81c4 0016a97c 00000010 ffffffff 00000028 00000000
Backtrace: 
[] (eth_type_trans+0x0/0x11c) from [] (axusbnet_skb_return+0x28/0xb4 [asix])
 r7:c3ae5006 r6:00000052 r5:c3ace2c0 r4:c3afe9c0
[] (axusbnet_skb_return+0x0/0xb4 [asix]) from [] (ax88772_rx_fixup+0x6c/0x1cc [asix])
 r5:c3afe9c0 r4:c3ae5006
[] (ax88772_rx_fixup+0x0/0x1cc [asix]) from [] (axusbnet_bh+0xd0/0x2c0 [asix])
[] (axusbnet_bh+0x0/0x2c0 [asix]) from [] (tasklet_action+0x78/0xf0)
 r9:0000000a r8:c3af8000 r7:00000000 r6:c0535220 r5:c04d96a8
r4:00000000
[] (tasklet_action+0x0/0xf0) from [] (__do_softirq+0x90/0x120)
 r7:00000006 r6:00000100 r5:00000001 r4:00000018
[] (__do_softirq+0x0/0x120) from [] (irq_exit+0x48/0x50)
[] (irq_exit+0x0/0x50) from [] (asm_do_IRQ+0x48/0x8c)
[] (asm_do_IRQ+0x0/0x8c) from [] (__irq_svc+0x24/0xa0)
Exception stack(0xc3af9cd8 to 0xc3af9d20)
9cc0:                                                       c34084dc 00000162
9ce0: 00000000 001d9527 c34084dc 00000162 c3ab4000 c3ac8080 00000162 c3af9d88
9d00: c34084d8 c3af9d34 c3af9d38 c3af9d20 c0075c5c c014d4b4 80000013 ffffffff
 r7:c3ac8080 r6:04000000 r5:f4000000 r4:ffffffff
[] (find_get_page+0x0/0x84) from [] (filemap_fault+0x6c/0x3bc)
 r5:c3aafe70 r4:00000000
[] (filemap_fault+0x0/0x3bc) from [] (__do_fault+0x58/0x3e0)
[] (__do_fault+0x0/0x3e0) from [] (handle_mm_fault+0x104/0xae8)
[] (handle_mm_fault+0x0/0xae8) from [] (do_page_fault+0x1a4/0x200)
[] (do_page_fault+0x0/0x200) from [] (do_translation_fault+0x78/0x80)
[] (do_translation_fault+0x0/0x80) from [] (do_PrefetchAbort+0x40/0xa4)
 r7:c04d6868 r6:00000005 r5:001e762c r4:c04d6818
[] (do_PrefetchAbort+0x0/0xa4) from [] (ret_from_exception+0x0/0x10)
Exception stack(0xc3af9fb0 to 0xc3af9ff8)
9fa0:                                     00000000 00000000 001e7628 0016a97c
9fc0: 00000002 001e762c 000e8198 00000000 00000000 00000003 00000000 bef4ae74
9fe0: 000e8198 bef4acd8 000e81c4 0016a97c 00000010 ffffffff
Code: e1a04001 e3a0100e ebff979e e596e088 (e5de3000) 
eth1: ax88772a - Link status is: 0
---[ end trace a1d5403463fbccb5 ]---
Kernel panic - not syncing: Fatal exception in interrupt
Backtrace: 
[] (dump_backtrace+0x0/0x10c) from [] (dump_stack+0x18/0x1c)
 r7:c03085a8 r6:c05148f0 r5:c3af99cf r4:c03085a8
[] (dump_stack+0x0/0x1c) from [] (panic+0x4c/0x134)
eth1: ax88772a - Link status is: 1
[] (panic+0x0/0x134) from [] (die+0x204/0x240)
 r3:00000100 r2:c04d9638 r1:00007a79 r0:c0464320
[] (die+0x0/0x240) from [] (__do_kernel_fault+0x6c/0x7c)
[] (__do_kernel_fault+0x0/0x7c) from [] (do_page_fault+0x148/0x200)
 r7:c3aca300 r6:000000f2 r5:c3aa1d80 r4:c04d6618
[] (do_page_fault+0x0/0x200) from [] (do_DataAbort+0x40/0xa4)
[] (do_DataAbort+0x0/0xa4) from [] (__dabt_svc+0x40/0x60)
Exception stack(0xc3af9b70 to 0xc3af9bb8)
9b60:                                     00000100 0000000e 00000000 000000f2
9b80: c3ace000 c3ace2c0 c3afe9c0 c3ae5006 c3afe300 c3ace2c0 00000052 c3af9bd4
9ba0: c3afe9c0 c3af9bb8 000000f2 c03085a8 20000013 ffffffff
[] (eth_type_trans+0x0/0x11c) from [] (axusbnet_skb_return+0x28/0xb4 [asix])
 r7:c3ae5006 r6:00000052 r5:c3ace2c0 r4:c3afe9c0
[] (axusbnet_skb_return+0x0/0xb4 [asix]) from [] (ax88772_rx_fixup+0x6c/0x1cc [asix])
 r5:c3afe9c0 r4:c3ae5006
[] (ax88772_rx_fixup+0x0/0x1cc [asix]) from [] (axusbnet_bh+0xd0/0x2c0 [asix])
[] (axusbnet_bh+0x0/0x2c0 [asix]) from [] (tasklet_action+0x78/0xf0)
 r9:0000000a r8:c3af8000 r7:00000000 r6:c0535220 r5:c04d96a8
r4:00000000
[] (tasklet_action+0x0/0xf0) from [] (__do_softirq+0x90/0x120)
 r7:00000006 r6:00000100 r5:00000001 r4:00000018
[] (__do_softirq+0x0/0x120) from [] (irq_exit+0x48/0x50)
[] (irq_exit+0x0/0x50) from [] (asm_do_IRQ+0x48/0x8c)
[] (asm_do_IRQ+0x0/0x8c) from [] (__irq_svc+0x24/0xa0)
Exception stack(0xc3af9cd8 to 0xc3af9d20)
9cc0:                                                       c34084dc 00000162
9ce0: 00000000 001d9527 c34084dc 00000162 c3ab4000 c3ac8080 00000162 c3af9d88
9d00: c34084d8 c3af9d34 c3af9d38 c3af9d20 c0075c5c c014d4b4 80000013 ffffffff
 r7:c3ac8080 r6:04000000 r5:f4000000 r4:ffffffff
[] (find_get_page+0x0/0x84) from [] (filemap_fault+0x6c/0x3bc)
 r5:c3aafe70 r4:00000000
[] (filemap_fault+0x0/0x3bc) from [] (__do_fault+0x58/0x3e0)
[] (__do_fault+0x0/0x3e0) from [] (handle_mm_fault+0x104/0xae8)
[] (handle_mm_fault+0x0/0xae8) from [] (do_page_fault+0x1a4/0x200)
[] (do_page_fault+0x0/0x200) from [] (do_translation_fault+0x78/0x80)
[] (do_translation_fault+0x0/0x80) from [] (do_PrefetchAbort+0x40/0xa4)
 r7:c04d6868 r6:00000005 r5:001e762c r4:c04d6818
[] (do_PrefetchAbort+0x0/0xa4) from [] (ret_from_exception+0x0/0x10)
Exception stack(0xc3af9fb0 to 0xc3af9ff8)
9fa0:                                     00000000 00000000 001e7628 0016a97c
9fc0: 00000002 001e762c 000e8198 00000000 00000000 00000003 00000000 bef4ae74
9fe0: 000e8198 bef4acd8 000e81c4 0016a97c 00000010 ffffffff
eth1: ax88772a - Link status is: 0
 

我很好奇为什么在没有编进802.1d Ethernet Bridging 模块之前，驱动一切正常，但是把网桥模块编译进去之后救出问题了呢？照理说两个模块应该不会发生冲突啊？

建议你去友善之臂的论坛问吧。

在eth_type_trans函数中，使用一个空指针，你使用ifconfig先查看是否存在eth1