我们如何用C语言编译内核代码？

我不熟悉C和Linux。我正在尝试编译下面的代码，但在编译时出现了一些致命错误。任何关于修复此问题的帮助都将不胜感激

下面是代码

measurecpu.c

：

#include <linux/module.h>      
#include <linux/kernel.h>      
#include <linux/init.h>         
#include <linux/hardirq.h>
#include <linux/preempt.h>
#include <linux/sched.h>
#include<stdio.h>

int main() {

uint64_t start, end;
int i=0;
asm volatile ("CPUID \ n \ t" "RDTSC \ n \ t" "mov %%edx, %0 \ n \ t" "mov %%eax, %1 \ n \ t": "=r" (cycles_high), "=r" (cycles_low)::  "%rax", "%rbx", "%rcx", "%rdx");

for(i=0; i<200000;i++) {}

asm volatile ("RDTSCP \ n \ t" "mov %%edx, %0 \ n \ t" "mov %%eax, %1 \ n \ t" "CPUID \ n \ t": "=r" (cycles_high1), "=r" (cycles_low1)::  "%rax", "%rbx", "%rcx", "%rdx");


start = ( ((uint64_t)cycles_high << 32) | cycles_low );
 end = ( ((uint64_t)cycles_high1 << 32) | cycles_low1 );
printk(KERN_INFO " \ n function execution time is %llu clock cycles",(end - start));

}

我得到这个错误：

measurecpu.c:1:32: fatal error: linux/module.h: No such file or directory
 #include <linux/module.h>      
                                ^
compilation terminated.

measurecpu.c:1:32:致命错误：linux/module.h:没有这样的文件或目录
#包括
^
编译终止。

我正试图以这种方式编译它

---

gcc-c-O2-W-Wall-isystem/lib/modules/'uname-r'/build/include-D_内核u-D模块measurecpu.c

通常编译内核模块的方法是使用内核构建系统，即使用

make

而不是直接使用

gcc

。您需要创建一个

Makefile

并指定对象，在您的案例中，这是行

obj-m:=measurecpu.o

。然后在同一目录中发出

make

命令，该命令将生成内核对象文件measurecpu.ko

# If KERNELRELEASE is defined, we've been invoked from the
# kernel build system and can use its language.
ifneq ($(KERNELRELEASE),)
    obj-m := measurecpu.o

# Otherwise we were called directly from the command
# line; invoke the kernel build system.
else
    KERNELDIR ?= /lib/modules/$(shell uname -r)/build
    PWD := $(shell pwd)

default:
    $(MAKE) -C $(KERNELDIR) M=$(PWD) modules

clean:
    $(MAKE) -C $(KERNELDIR) M=$(PWD) modules clean

endif

---

请注意，内核模块不是用户空间程序，所以您不能只运行它。您需要通过

insmod

告诉内核关于该内核模块的信息，并通过

dmesg

检查结果，因为错误消息清楚地表明，编译器在

linux

文件夹中找不到头文件

module.h

---

请参阅本文：

如果出现构建错误，则无法获得分段错误。哎呀，我的意思是如何构建代码。对不起，用错了词。将编辑/lib/modules/'uname-r'/build/include

# If KERNELRELEASE is defined, we've been invoked from the
# kernel build system and can use its language.
ifneq ($(KERNELRELEASE),)
    obj-m := measurecpu.o

# Otherwise we were called directly from the command
# line; invoke the kernel build system.
else
    KERNELDIR ?= /lib/modules/$(shell uname -r)/build
    PWD := $(shell pwd)

default:
    $(MAKE) -C $(KERNELDIR) M=$(PWD) modules

clean:
    $(MAKE) -C $(KERNELDIR) M=$(PWD) modules clean

endif