c - 从多个文件编译内核模块时主文件未编译

Question

首先我想说一下，我一直在寻找类似的问题，解决方案是什么。我发现它是:

obj-m := module.o
module-objs := extra.o

但它对我不起作用......

这里是整个项目的源码:

轴 Controller .h:

#ifndef _AXIS_CONTROLLER_H
#define _AXIS_CONTROLLER_H

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/hrtimer.h>
#include <linux/ktime.h>

struct axis_controller {
    struct hrtimer timer;
    int state;
};

static inline struct hrtimer* axis_controller_get_timer(struct axis_controller* axis_controller);

static inline void axis_controller_reset_state(struct axis_controller* axis_controller);

inline void axis_controller_init(struct axis_controller* axis_controller, enum hrtimer_restart (*function)(struct hrtimer *));

inline int axis_controller_clean(struct axis_controller* axis_controller);

inline void axis_controller_change_state(struct axis_controller* axis_controller, unsigned long sec, unsigned long nano_sec);

inline void axis_controller_controll(struct axis_controller* axis_controller);

#endif

轴 Controller .c:

#include "axis_controller.h"

MODULE_LICENSE("GPL v2");

struct hrtimer* axis_controller_get_timer(struct axis_controller* axis_controller) {
    return &(axis_controller->timer);
}

void axis_controller_reset_state(struct axis_controller* axis_controller) {
    axis_controller->state = 0;
}

void axis_controller_init(struct axis_controller* axis_controller, enum hrtimer_restart (*function)(struct hrtimer *)) {
    hrtimer_init(axis_controller_get_timer(axis_controller), CLOCK_MONOTONIC, HRTIMER_MODE_REL);
    axis_controller->timer.function = function;
    axis_controller_reset_state(axis_controller);
}

int axis_controller_clean(struct axis_controller* axis_controller) {
    return hrtimer_try_to_cancel(axis_controller_get_timer(axis_controller));
}
void axis_controller_change_state(struct axis_controller* axis_controller, unsigned long sec, unsigned long nano_sec) {
    axis_controller->state = !axis_controller->state;
    hrtimer_start(axis_controller_get_timer(axis_controller), ktime_set(sec, nano_sec), HRTIMER_MODE_REL);
}
void axis_controller_controll(struct axis_controller* axis_controller) {
    axis_controller_reset_state(axis_controller);
    axis_controller->timer.function(axis_controller_get_timer(axis_controller));
}

//printk(KERN_INFO "axis_controller.c\n");

CNC_controller.c:

#include <linux/kernel.h>
#include <linux/module.h>
#include "axis_controller/axis_controller.h"

MODULE_LICENSE("GPL v2");
MODULE_AUTHOR("Ivo Stratev (NoHomey)");
MODULE_DESCRIPTION("CNC Controller");

printk(KERN_INFO "CNC_controller.c\n");

static int return_value;
static struct axis_controller test;

static enum hrtimer_restart my_callback(struct hrtimer *timer) {
  printk(KERN_INFO "my_hrtimer_callback called\n");
  return HRTIMER_NORESTART;
}

static int __init on_load(void) {
  printk("on_load\n");
  axis_controller_init(&test, my_callback);

  axis_controller_controll(&test);

  return 0;
}

static void on_unload(void) {
  printk("on_unload\n");
  axis_controller_clean(&test);
  return;
}

module_init(on_load);
module_exit(on_unload);

生成文件:

__name__ = CNC_controller
__major__ = 243
__ioctl_header__ = /usr/include/$(__name__)_ioctl.h
make_module_action = make -C /lib/modules/$(shell uname -r)/build M=$(PWD)
obj-m := $(__name__).o
CNC_controller-objs := axis_controller/axis_controller.o

all: clean
    $(make_module_action) modules

clean:
    $(make_module_action) clean

load:
    insmod $(__name__).ko

unload:
    rmmod -f $(__name__)

device:
    mknod /dev/$(__name__) c $(__major__) 0
    chmod 777 /dev/$(__name__)

remove:
    rm -f /dev/$(__name__)

header:
    rm -f $(__ioctl_header__)
    cp $(__name__).h $(__ioctl_header__)
    chmod 555 $(__ioctl_header__)

这是构建过程:

ivo@ivo-Inspiron-5558:~/CNC-Controller$ make
make -C /lib/modules/4.4.0-28-generic/build M=/home/ivo/CNC-Controller clean
make[1]: Entering directory '/usr/src/linux-headers-4.4.0-28-generic'
CLEAN   /home/ivo/CNC-Controller/.tmp_versions
CLEAN   /home/ivo/CNC-Controller/Module.symvers
make[1]: Leaving directory '/usr/src/linux-headers-4.4.0-28-generic'
make -C /lib/modules/4.4.0-28-generic/build M=/home/ivo/CNC-Controller modules
make[1]: Entering directory '/usr/src/linux-headers-4.4.0-28-generic'
CC [M]  /home/ivo/CNC-Controller/axis_controller/axis_controller.o
LD [M]  /home/ivo/CNC-Controller/CNC_controller.o
Building modules, stage 2.
MODPOST 1 modules
CC      /home/ivo/CNC-Controller/CNC_controller.mod.o
LD [M]  /home/ivo/CNC-Controller/CNC_controller.ko
make[1]: Leaving directory '/usr/src/linux-headers-4.4.0-28-generic'
ivo@ivo-Inspiron-5558:~/CNC-Controller$ 

当我删除行时

CNC_controller-objs := axis_controller/axis_controller.o

构建过程是:

ivo@ivo-Inspiron-5558:~/CNC-Controller$ make
make -C /lib/modules/4.4.0-28-generic/build M=/home/ivo/CNC-Controller clean
make[1]: Entering directory '/usr/src/linux-headers-4.4.0-28-generic'
CLEAN   /home/ivo/CNC-Controller/.tmp_versions
CLEAN   /home/ivo/CNC-Controller/Module.symvers
make[1]: Leaving directory '/usr/src/linux-headers-4.4.0-28-generic'
make -C /lib/modules/4.4.0-28-generic/build M=/home/ivo/CNC-Controller modules
make[1]: Entering directory '/usr/src/linux-headers-4.4.0-28-generic'
CC [M]  /home/ivo/CNC-Controller/CNC_controller.o
In file included from include/linux/printk.h:6:0,
                from include/linux/kernel.h:13,
                from /home/ivo/CNC-Controller/CNC_controller.c:2:
include/linux/kern_levels.h:4:18: error: expected declaration specifiers or ‘...’ before string constant
#define KERN_SOH "\001"  /* ASCII Start Of Header */
                ^
include/linux/kern_levels.h:13:19: note: in expansion of macro ‘KERN_SOH’
#define KERN_INFO KERN_SOH "6" /* informational */
                ^
/home/ivo/CNC-Controller/CNC_controller.c:10:8: note: in expansion of macro ‘KERN_INFO’
printk(KERN_INFO "CNC_controller.c\n");
        ^
In file included from /home/ivo/CNC-Controller/CNC_controller.c:4:0:
/home/ivo/CNC-Controller/axis_controller/axis_controller.h:14:31: warning: ‘axis_controller_get_timer’ declared ‘static’ but never defined [-Wunused-function]
static inline struct hrtimer* axis_controller_get_timer(struct axis_controller* axis_controller);
                            ^
/home/ivo/CNC-Controller/axis_controller/axis_controller.h:16:20: warning: ‘axis_controller_reset_state’ declared ‘static’ but never defined [-Wunused-function]
static inline void axis_controller_reset_state(struct axis_controller* axis_controller);
                    ^
scripts/Makefile.build:264: recipe for target '/home/ivo/CNC-Controller/CNC_controller.o' failed
make[2]: *** [/home/ivo/CNC-Controller/CNC_controller.o] Error 1
Makefile:1403: recipe for target '_module_/home/ivo/CNC-Controller' failed
make[1]: *** [_module_/home/ivo/CNC-Controller] Error 2
make[1]: Leaving directory '/usr/src/linux-headers-4.4.0-28-generic'
Makefile:10: recipe for target 'all' failed
make: *** [all] Error 2
ivo@ivo-Inspiron-5558:~/CNC-Controller$ 

这就是我认为它没有编译的原因，因为它记录了 printk 错误:

include/linux/kern_levels.h:4:18: error: expected declaration specifiers or ‘...’ before string constant
    #define KERN_SOH "\001"  /* ASCII Start Of Header *

知道我做错了什么吗？因为我做了我看到别人在做的事情......

Answer 1

你有两个问题:

• 你不能在全局范围内使用 printk。这必须转移到一个函数中。

• 尝试构建多文件模块时，您不能拥有与模块同名的 C 文件。也就是说，重命名 CNC_controller.c 或 .ko 例如，重命名 CNC_controller.c CNC_controller_main.c 并使用:

  CNC_controller-objs := CNC_controller_main.c axis_controller/axis_controller.o