linux设备驱动——scull源码编译问题

我的环境是ubuntu12.04

内核版本：3.13.0-32-generic

这个内核版本算是比较新的，scull源码编译会出现很多问题以下对这些问题进行归纳总结：

今天对程序进行编译，结果出现

make -C /lib/modules/3.3.2-6.fc16.x86_64/build M=/home/jqzeng/workSpace/ldd3/ldd3-samples-1.0.0/scull LDDINC=/home/jqzeng/workSpace/ldd3/ldd3-samples-1.0.0/scull/../include modules

make[1]: Entering directory `/usr/src/kernels/3.3.2-6.fc16.x86_64'

scripts/Makefile.build:49: *** CFLAGS was changed in "/home/jqzeng/workSpace/ldd3/ldd3-samples-1.0.0/scull/Makefile". Fix it to use ccflags-y.  Stop.

make[1]: *** [_module_/home/jqzeng/workSpace/ldd3/ldd3-samples-1.0.0/scull] Error 2

make[1]: Leaving directory `/usr/src/kernels/3.3.2-6.fc16.x86_64'

make: *** [modules] Error 2

vim /usr/src/kernels/3.3.2-6.fc16.x86_64/scripts/Makefile.build

第49行内容

 # If the save-* variables changed error out

 47 ifeq ($(KBUILD_NOPEDANTIC),)

 48         ifneq ("$(save-cflags)","$(CFLAGS)")

 49                 $(error CFLAGS was changed in "$(kbuild-file)". Fix it to use ccflags-y)

 50         endif

 51 endif

没有定义KBUILD_NOPEDANTIC，且修改了CFLAGS，导致编译不能继续。我想这里是开发者为了防止修改CFLAG进行的保护措施，解决办法可以在编译前定义KBUILD_NOPEDANTIC，export KBUILD_NOPEDANTIC=1或者修改Makefile中的CFLAGS为ccflags-y

继续编译，#include 出现include的linux下没有config.h这个文件

/home/jqzeng/workSpace/ldd3/ldd3-samples-1.0.0/scull/main.c:17:26: fatal error: linux/config.h: No such file or directory

把这个文件加上去就好了。现在较新的内核已经弃用了config.h。

sudo vim /usr/src/kernels/3.3.2-6.fc16.x86_64/include/linux/config.h

 #ifndef _LINUX_CONFIG_H

 #define _LINUX_CONFIG_H

 #endif

OK!这个问题解决了。

接下来有出问题了

/home/jqzeng/workSpace/ldd3/ldd3-samples-1.0.0/scull/main.c:556:2: error: unknown field 'ioctl' specified in initializer

ioctl是未知域，查看file_operations结构体，在build/inlcude/linux/fs.h中的1603行定义，前面有两句话

 /* These macros are for out of kernel modules to test that

  * the kernel supports the unlocked_ioctl and compat_ioctl

  * fields in struct file_operations. */

根据开发者的意见，ioctl使用了大内核锁，这个是不安全的，新的kerne将l不再支持ioctl方法，而应该使用 unlocked_ioctl或者compat_ioctl。修改main.c中556行的.ioctl为unlocked_ioctl，这个错误不会出现了。同时，这个函数指针的原型也改变了！

long (*unlocked_ioctl) (struct file *, unsigned int, unsigned long); 

与原来的ioctl函数原型相比少传递了struct inode *inode 这个变量，因此我们的实现scull_ioctl需要变为

main.c

394  int scull_ioctl(struct file *filp,

395                        unsigned int cmd, unsigned long arg)

scull.h

131 int     scull_ioctl(struct file *filp,

132                     unsigned int cmd, unsigned long arg);

接着，出现另外一个问题：

/home/jqzeng/workSpace/ldd3/ldd3-samples-1.0.0/scull/main.c:652:3: error: implicit declaration of function 'init_MUTEX

与前一个错误来源一样，init_MUTEX(&sem)在新内核里也被弃用了。用sema_init(&sem,1)进行替换可解决此问题。

好了，main.c的问题解决了，pipe.c编译的时候出现了一大堆问题了。

/home/jqzeng/workSpace/ldd3/ldd3-samples-1.0.0/scull/pipe.c:130:3: error: dereferencing pointer to incomplete type

/home/jqzeng/workSpace/ldd3/ldd3-samples-1.0.0/scull/pipe.c:131:7: error: 'TASK_INTERRUPTIBLE' undeclared (first use in this function)

/home/jqzeng/workSpace/ldd3/ldd3-samples-1.0.0/scull/pipe.c:131:7: note: each undeclared identifier is reported only once for each function it appears in

/home/jqzeng/workSpace/ldd3/ldd3-samples-1.0.0/scull/pipe.c:131:3: error: implicit declaration of function 'signal_pending' [-Werror=implicit-function-declaration]

/home/jqzeng/workSpace/ldd3/ldd3-samples-1.0.0/scull/pipe.c:131:3: error: implicit declaration of function 'schedule' [-Werror=implicit-function-declaration]

/home/jqzeng/workSpace/ldd3/ldd3-samples-1.0.0/scull/pipe.c:153:2: error: dereferencing pointer to incomplete type

/home/jqzeng/workSpace/ldd3/ldd3-samples-1.0.0/scull/pipe.c: In function 'scull_getwritespace':

/home/jqzeng/workSpace/ldd3/ldd3-samples-1.0.0/scull/pipe.c:167:3: error: dereferencing pointer to incomplete type

/home/jqzeng/workSpace/ldd3/ldd3-samples-1.0.0/scull/pipe.c:168:38: error: 'TASK_INTERRUPTIBLE' undeclared (first use in this function)

/home/jqzeng/workSpace/ldd3/ldd3-samples-1.0.0/scull/pipe.c: In function 'scull_p_write':

/home/jqzeng/workSpace/ldd3/ldd3-samples-1.0.0/scull/pipe.c:219:2: error: 'TASK_INTERRUPTIBLE' undeclared (first use in this function)

/home/jqzeng/workSpace/ldd3/ldd3-samples-1.0.0/scull/pipe.c:223:34: error: 'SIGIO' undeclared (first use in this function)

/home/jqzeng/workSpace/ldd3/ldd3-samples-1.0.0/scull/pipe.c:223:41: error: 'POLL_IN' undeclared (first use in this function)

/home/jqzeng/workSpace/ldd3/ldd3-samples-1.0.0/scull/pipe.c:224:2: error: dereferencing pointer to incomplete type

/home/jqzeng/workSpace/ldd3/ldd3-samples-1.0.0/scull/pipe.c: At top level:

/home/jqzeng/workSpace/ldd3/ldd3-samples-1.0.0/scull/pipe.c:319:2: warning: initialization from incompatible pointer type [enabled by default]

/home/jqzeng/workSpace/ldd3/ldd3-samples-1.0.0/scull/pipe.c:319:2: warning: (near initialization for 'scull_pipe_fops.unlocked_ioctl') [enabled by default]

cc1: some warnings being treated as errors

太吓人了，不过仔细看这些错误，大部分都是类型未定义，怎么办？我们可以用命令在 /lib/modules/$(uname -r)/build/include/linux 文件夹下搜搜

find ./ -type f -exec grep "TASK_INTERRUPTIBLE" {} \; -print

结果显示

#define TASK_INTERRUPTIBLE1

#define TASK_NORMAL(TASK_INTERRUPTIBLE | TASK_UNINTERRUPTIBLE)

#define TASK_REPORT(TASK_RUNNING | TASK_INTERRUPTIBLE | \

if (!(state & (TASK_INTERRUPTIBLE | TASK_WAKEKILL)))

return (state & TASK_INTERRUPTIBLE) || __fatal_signal_pending(p);

./sched.h

原来改到了在sched.h中定义了。把这个头文件加到pipe.c中

#include

再编译，发现access.c也出现跟pipe.c一样的问题，再把sched.h添加进去。

还是出现问题：

/home/jqzeng/workSpace/ldd3/ldd3-samples-1.0.0/scull/access.c:99:34: error: 'SPIN_LOCK_UNLOCKED' undeclared here (not in a function)

原因，SPIN_LOCK_UNLOCKED在新内核中被弃用，用新内核编译的人伤不起阿！解决办法，添加头文件

#include

修改定义

static spinlock_t scull_u_lock = SPIN_LOCK_UNLOCKED;

为

static DEFINE_SPINLOCK(scull_u_lock);

问题：

/home/jqzeng/workSpace/ldd3/ldd3-samples-1.0.0/scull/access.c:107:29: error: 'struct task_struct' has no member named 'uid'

/home/jqzeng/workSpace/ldd3/ldd3-samples-1.0.0/scull/access.c:108:29: error: 'struct task_struct' has no member named 'euid'

原因：新的struct task_struct 定义有变化，uid和euid在cred结构体中。

解决办法：加头文件cred.h，将 current->uid改为current->cred->uid，current->euid改为current->cred->euid

#include

108         if (scull_u_count &&

109                         (scull_u_owner != current->cred->uid) &&  /* allow user */

110                         (scull_u_owner != current->cred->euid) && /* allow whoever did su */

...

117                 scull_u_owner = current->cred->uid; /* grab it */

到这里后改过还是问题

/home/kevin/Documents/examples/scull/access.c: In function ‘scull_u_open’:
/home/kevin/Documents/examples/scull/access.c:109:19: error: invalid operands to binary != (have ‘uid_t’ and ‘kuid_t’)
/home/kevin/Documents/examples/scull/access.c:110:19: error: invalid operands to binary != (have ‘uid_t’ and ‘kuid_t’)

解决办法，参考如下连接

http://bbs.csdn.net/topics/390734456

http://lists.infradead.org/pipermail/linux-pmfs/2013-April/000010.html

 current->cred->uid为kuid_t类型，需要继续获取val才可以进行比较

typedef struct {uid_t val;} kuid_t;

代码改过后

scull_w_owner == current->cred->uid.val ||
scull_w_owner == current->cred->euid.val ||

这里贴上通过编译的代码，见附件。