找打空指针出错位置
比如：ch37x_spi_thread+0x13b8/0x1560

ffffff80085efe24+0x13c0 = 0xFFFFFF80085F11E4
c5 PC is at ch37x_spi_thread+0x13c0/0x1560

[ 434.544368] c5 LR is at ch37x_spi_thread+0x13b8/0x1560

在out/ud710_2h10/obj/kernel中找到System.map
查看ch37x_spi_thread函数的地址

**grep ch37x_spi_thread ./System.map**
ffffff80085efe24 t ch37x_spi_thread


ffffff80085efe24 t ch37x_spi_thread
	ffffff80085efe24 +0x13c0 = 

然后利用 gdb ./vmlinux

/bsp/out/ud710_2h10/obj/kernel$ **gdb ./vmlinux**
GNU gdb (Ubuntu 8.1-0ubuntu3.2) 8.1.0.20180409-git
Copyright (C) 2018 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>
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and "show warranty" for details.
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Type "show configuration" for configuration details.
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Reading symbols from ./vmlinux...done.
**(gdb) b *0xFFFFFF80085F11E4**
Breakpoint 1 at 0x85f11e4: file 
/kernel/kernel4.14/drivers/misc/ch37x_hcd/ch37x_hcd.c, line 1296.