c - Linux 内核模块 - 生成两个具有共享本地 header 的模块

Question

我有以下文件:buffer.c、buffer.h、chardevin.c、chardevout.c 和 生成文件。 chardevin.c 和chardevout.c 都是内核模块。两个内核模块都包含buffer.h，由buffer.c实现。理想情况下，我希望 makefile 在链接缓冲区实现时生成两个内核模块(即生成 chardevin.ko 和 chardevout.ko)。我似乎无法弄清楚这部分...

这是我的 Makefile 的内容:

obj-m += chardevin.o chardevout.o
obj-y += buffer.c

all:
    make -C /lib/modules/$(shell uname -r)/build/ M=$(PWD) modules

但是，我得到以下输出:

kylemart@ubuntu:/mnt/hgfs/ucf-os-linux/SplitDriverWithMutex$ make
make -C /lib/modules/4.4.0-31-generic/build/ M=/mnt/hgfs/ucf-os-linux/SplitDriverWithMutex modules
make[1]: Entering directory `/usr/src/linux-headers-4.4.0-31-generic'
  CC [M]  /mnt/hgfs/ucf-os-linux/SplitDriverWithMutex/chardevin.o
  CC [M]  /mnt/hgfs/ucf-os-linux/SplitDriverWithMutex/chardevout.o
  Building modules, stage 2.
  MODPOST 2 modules
WARNING: "buffer_read" [/mnt/hgfs/ucf-os-linux/SplitDriverWithMutex/chardevout.ko] undefined!
WARNING: "buffer_length" [/mnt/hgfs/ucf-os-linux/SplitDriverWithMutex/chardevout.ko] undefined!
WARNING: "buffer_write" [/mnt/hgfs/ucf-os-linux/SplitDriverWithMutex/chardevin.ko] undefined!
WARNING: "buffer_length" [/mnt/hgfs/ucf-os-linux/SplitDriverWithMutex/chardevin.ko] undefined!
  CC      /mnt/hgfs/ucf-os-linux/SplitDriverWithMutex/chardevin.mod.o
  LD [M]  /mnt/hgfs/ucf-os-linux/SplitDriverWithMutex/chardevin.ko
  CC      /mnt/hgfs/ucf-os-linux/SplitDriverWithMutex/chardevout.mod.o
  LD [M]  /mnt/hgfs/ucf-os-linux/SplitDriverWithMutex/chardevout.ko
make[1]: Leaving directory `/usr/src/linux-headers-4.4.0-31-generic' 

buffer.h 的内容如下:

#ifndef BUFFER_H
#define BUFFER_H

ssize_t buffer_write(const char *src, size_t n);
ssize_t buffer_read(char *dest, size_t n);
size_t buffer_length(void);

#endif 

我做错了什么？

编辑:

在 Makefile 中将“buffer.c”更改为“buffer.o”。这是输出:

kylemart@ubuntu:/mnt/hgfs/ucf-os-linux/SplitDriverWithMutex$ make
make -C /lib/modules/4.4.0-31-generic/build/ M=/mnt/hgfs/ucf-os-linux/SplitDriverWithMutex modules
make[1]: Entering directory `/usr/src/linux-headers-4.4.0-31-generic'
  Building modules, stage 2.
  MODPOST 2 modules
WARNING: "buffer_read" [/mnt/hgfs/ucf-os-linux/SplitDriverWithMutex/chardevout.ko] undefined!
WARNING: "buffer_length" [/mnt/hgfs/ucf-os-linux/SplitDriverWithMutex/chardevout.ko] undefined!
WARNING: "buffer_write" [/mnt/hgfs/ucf-os-linux/SplitDriverWithMutex/chardevin.ko] undefined!
WARNING: "buffer_length" [/mnt/hgfs/ucf-os-linux/SplitDriverWithMutex/chardevin.ko] undefined!
make[1]: Leaving directory `/usr/src/linux-headers-4.4.0-31-generic' 

Answer 1

替换如下:

obj-y += buffer.c --> obj-y += buffer.o