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问题现象：

guang@arm-vexpress:/ # ls

bin lib mnt sys usr dev linuxrc proc test var etc lost+found sbin tmp guang@arm-vexpress:/ # cd test/ guang@arm-vexpress:/test # insmod qemu.ko qemu: loading out-of-tree module taints kernel. guang@arm-vexpress:/test # lsmod qemu 16384 0 - Live 0x7f000000 (O) guang@arm-vexpress:/test # insmod qemu.ko insmod: can’t insert ‘qemu.ko’: File exists

问题1：如上，首次加载ko，提示out-of-tree，lsmod确显示ko已加载，insmod会报ko已经存在，wiki参考说是“内核在编译的时候选择支持内核签名机制，据说在3.7版本后面就支持”，不太确定，wiki地址：

guang@arm-vexpress:/test # rmmod qemu.ko

[Info]Hello! Enter QEMU. guang@arm-vexpress:/test # insmod qemu.ko [Info]Hello! Exit QEMU. guang@arm-vexpress:/test # lsmod qemu 16384 0 - Live 0x7f010000 (O) guang@arm-vexpress:/test # rmmod qemu.ko [Info]Hello! Enter QEMU. guang@arm-vexpress:/test # lsmod guang@arm-vexpress:/test #

问题2，如下，insmod和rmmod的log正好相反，很奇怪

guang@arm-vexpress:/test # lsmod

guang@arm-vexpress:/test # insmod qemu.ko [Info]Hello! Exit QEMU. guang@arm-vexpress:/test # rmmod qemu.ko [Info]Hello! Enter QEMU. guang@arm-vexpress:/test #

源码如下：

// qemu.c#include 
   
    #include 
    
     static int __init qemu_init (void){        printk (KERN_INFO"[Info]Hello! Enter QEMU.");        return 0;}module_init (qemu_init);static void __exit qemu_exit (void){        printk (KERN_INFO"[Info]Hello! Exit QEMU.");}module_exit (qemu_exit);MODULE_AUTHOR ("Guang-kylin");MODULE_LICENSE ("GPL v2");MODULE_DESCRIPTION ("A simple qume test module");MODULE_ALIAS ("QEMU module");
    
   

// makefileKDIR=/home/guang/Develop/linux-stablePWD=$(shell pwd)# Kernel modulesobj-m += qemu.omodule-objs = qemu.oARCH=armCROSS_COMPILE=arm-linux-gnueabi-CC := $(CROSS_COMPILE)gccLD := $(CROSS_COMPILE)ld#EXTRA_CFLAGS=-g -O0default:        make -C $(KDIR) M=$(PWD) modulesclean:        rm -f *.ko *.o *.mod.c *.symvers *.order