ldd3 源码编译之 scullc 字符设备驱动 错误解决办法

使用内核版本-linux-3.2 

错误1：

1. make -C /lib/modules/3.2.0/build M=/home/wrk/works/drivers/ldd3/examples/scullc LDDINC=/home/wrk/works/drivers/ldd3/examples/scullc modules
   
2. make[1]: Entering directory `/home/wrk/works/drivers/linux-kernel/linux-3.2'
   
3. scripts/Makefile.build:49: *** CFLAGS was changed in "/home/wrk/works/drivers/ldd3/examples/scullc/Makefile". Fix it to use ccflags-y. Stop.
   
4. make[1]: *** [_module_/home/wrk/works/drivers/ldd3/examples/scullc] Error 2
   
5. make[1]: Leaving directory `/home/wrk/works/drivers/linux-kernel/linux-3.2'
   
6. make: *** [modules] Error 2

这个错误还比较好解决，像提示的那样在Makefile中用ccflags-y替换CFLAGS 

错误2：

1. /home/wrk/works/drivers/ldd3/examples/scullc/main.c:52:1: error: unknown type name ‘kmem_cache_t’

这是因为kmem_cache_t结构被换成了kmem_cache。而kmem_cache定义在<linux/slab_def.h>和<linux/slub_def.h>。但是你并不需要包含这两个文件中的一个。因为<linux/slab.h>会根据CONFIG_SLUB等来判断具体包含<linux/slab_def.h>，还是<linux/slub_def.h>。故例程中需要将

kmem_cache_t *scullc_cache;
改为：
struct kmem_cache *scullc_cache;

错误3：

1. /home/wrk/works/drivers/ldd3/examples/scullc/main.c: In function ‘scullc_defer_op’:
2. /home/wrk/works/drivers/ldd3/examples/scullc/main.c:437:54: error: macro "INIT_WORK" passed 3 arguments, but takes just 2
3. /home/wrk/works/drivers/ldd3/examples/scullc/main.c:437:2: error: ‘INIT_WORK’ undeclared (first use in this function)

这里需要将

1. INIT_WORK(&stuff->work, scull_do_deferred_op, stuff);

改为：

1. INIT_WORK(&stuff->work, scull_do_deferred_op);

并且将scullc_do_deferred_op函数改为

1. static void scullc_do_deferred_op(struct work_struct *p)
   
2. {
   
3.         struct async_work *stuff = container_of(p, struct async_work, work);
   
4.         aio_complete(stuff->iocb, stuff->result, 0);
   
5.         kfree(stuff);
   
6. }

错误4： 

1. /home/wrk/works/drivers/ldd3/examples/scullc/main.c:467:2: error: unknown field ‘ioctl’ specified in initializer

这里因为内核接口变化需要将.ioctl改为 .unlocked_ioctl

错误5：

1. /home/wrk/works/drivers/ldd3/examples/scullc/main.c:558:4: error: too many arguments to function ‘kmem_cache_create’

函数kmem_cache_create的原型已经改变：
struct kmem_cache *kmem_cache_create(const char *, size_t, size_t, unsigned long, void (*)(void *));故调用它的时候应该将参数做出相应的改变。需要将最后一个NULL去掉。

下面来解决warning：

1. /home/wrk/works/drivers/ldd3/examples/scullc/main.c: In function ‘scullc_defer_op’:
2. /home/wrk/works/drivers/ldd3/examples/scullc/main.c:437:2: warning: assignment from incompatible pointer type [enabled by default]
3. /home/wrk/works/drivers/ldd3/examples/scullc/main.c:438:2: warning: passing argument 1 of ‘schedule_delayed_work’ from incompatible pointer type [enabled by default]
4. include/linux/workqueue.h:363:12: note: expected ‘struct delayed_work *’ but argument is of type ‘struct work_struct *’
5. /home/wrk/works/drivers/ldd3/examples/scullc/main.c: At top level:
6. /home/wrk/works/drivers/ldd3/examples/scullc/main.c:467:2: warning: initialization from incompatible pointer type [enabled by default]
7. /home/wrk/works/drivers/ldd3/examples/scullc/main.c:467:2: warning: (near initialization for ‘scullc_fops.unlocked_ioctl’) [enabled by default]
8. /home/wrk/works/drivers/ldd3/examples/scullc/main.c:470:2: warning: initialization from incompatible pointer type [enabled by default]
9. /home/wrk/works/drivers/ldd3/examples/scullc/main.c:470:2: warning: (near initialization for ‘scullc_fops.aio_read’) [enabled by default]
10. /home/wrk/works/drivers/ldd3/examples/scullc/main.c:471:2: warning: initialization from incompatible pointer type [enabled by default]
11. /home/wrk/works/drivers/ldd3/examples/scullc/main.c:471:2: warning: (near initialization for ‘scullc_fops.aio_write’) [enabled by default]

1.把

1. struct async_work {
2. struct kiocb *iocb;
3. int result;
4. struct work_struct work;
5. };

改为：

1. struct async_work {
2. struct kiocb *iocb;
3. int result;
4. struct delayed_work delayed_work;
5. }

然后把：

1. INIT_WORK(&stuff->work, scull_do_deferred_op, stuff);
2. schedule_delayed_work(&stuff->work, HZ/100);

改为：

1. INIT_DELAYED_WORK(&(stuff->delayed_work), scullc_do_deferred_op);
2. schedule_delayed_work(&(stuff->delayed_work), HZ/100);

再编译即可通过。

（我的环境是 linux-3.5，部分适用，但还有以下的问题出错 ）

1、main.c:652: error: implicit declaration of function ‘init_MUTEX’

该错误是因为init_MUTEX函数再新到内核中已经被废弃，不再使用，改成sema_init函数。因为原来到 init_MUTEX的实现里面调用到也是这个函数。

/*init_MUTEX(&scull_devices[i].sem);改成下面那样即可*/sema_init(&scull_devices[i].sem,1);

2. access.c:99: error: ‘SPIN_LOCK_UNLOCKED’ undeclared here (not in a function)

是说SPIN_LOCK_UNLOCKED不被认识了，其实也是被废弃了，改用DEFINE_SPINLOCK即可，如

/*static spinlock_t scull_w_lock = SPIN_LOCK_UNLOCKED; 改成下面到方式*/static DEFINE_SPINLOCK(scull_w_lock);

3. 另外，在编译成功后，运行 sudo ./scull_load 时会出错：

awk: line 1: syntax error at or near ==mknod: "0" 后缺少操作数请尝试执行"mknod --help"来获取更多信息。mknod: "1" 后缺少操作数请尝试执行"mknod --help"来获取更多信息。mknod: "2" 后缺少操作数请尝试执行"mknod --help"来获取更多信息。mknod: "3" 后缺少操作数请尝试执行"mknod --help"来获取更多信息。chgrp: 无法访问"/dev/scull[0-3]": 没有那个文件或目录chmod: 无法访问"/dev/scull[0-3]": 没有那个文件或目录mknod: "4" 后缺少操作数请尝试执行"mknod --help"来获取更多信息。mknod: "5" 后缺少操作数请尝试执行"mknod --help"来获取更多信息。mknod: "6" 后缺少操作数请尝试执行"mknod --help"来获取更多信息。mknod: "7" 后缺少操作数请尝试执行"mknod --help"来获取更多信息。chgrp: 无法访问"/dev/scullpipe[0-3]": 没有那个文件或目录chmod: 无法访问"/dev/scullpipe[0-3]": 没有那个文件或目录mknod: "8" 后缺少操作数请尝试执行"mknod --help"来获取更多信息。chgrp: 无法访问"/dev/scullsingle": 没有那个文件或目录chmod: 无法访问"/dev/scullsingle": 没有那个文件或目录mknod: "9" 后缺少操作数请尝试执行"mknod --help"来获取更多信息。chgrp: 无法访问"/dev/sculluid": 没有那个文件或目录chmod: 无法访问"/dev/sculluid": 没有那个文件或目录mknod: "10" 后缺少操作数请尝试执行"mknod --help"来获取更多信息。chgrp: 无法访问"/dev/scullwuid": 没有那个文件或目录chmod: 无法访问"/dev/scullwuid": 没有那个文件或目录mknod: "11" 后缺少操作数请尝试执行"mknod --help"来获取更多信息。chgrp: 无法访问"/dev/scullpriv": 没有那个文件或目录chmod: 无法访问"/dev/scullpriv": 没有那个文件或目录spark@spark-Dell:~/LDD3-ex/examples/scull$ ls /dev/scull*/dev/scull /dev/scullpipe

从第一行可看出，在运行 awk 命令时就已经出错，导致最后无法创建 scull0~3 ,解决办法：

在 scull_load 中，把

major=$(awk "\\$2==\"$module\" {print \\$1}" /proc/devices)

改为

major=$(awk "\$2==\"$module\" {print \$1}" /proc/devices)

至此，编译及加载都已OK

spark@spark-Dell:~/LDD3-ex/examples/scull$ sudo ./scull_loadinsmod: error inserting './scull.ko': -1 File existsspark@spark-Dell:~/LDD3-ex/examples/scull$ sudo ./scull_unloadspark@spark-Dell:~/LDD3-ex/examples/scull$ sudo ./scull_loadspark@spark-Dell:~/LDD3-ex/examples/scull$ ls /dev/scull*/dev/scull   /dev/scull2     /dev/scullpipe0  /dev/scullpipe3   /dev/sculluid/dev/scull0  /dev/scull3     /dev/scullpipe1  /dev/scullpriv    /dev/scullwuid/dev/scull1  /dev/scullpipe  /dev/scullpipe2  /dev/scullsinglespark@spark-Dell:~/LDD3-ex/examples/scull$ ls /proc/scull*/proc/scullmem  /proc/scullpipe  /proc/scullseq