Linux驱动调试中关于ioctl的问题

Posted 2020-11-01 mofei004

1、提示：错误： 初始值设定项里有未知的字段‘ioctl’

2.6以后的内核中file_operation结构体已经删除了ioctl函数，取代的是：
long (*unlocked_ioctl) (struct file *, unsigned int, unsigned long);
long (*compat_ioctl) (struct file *, unsigned int, unsigned long);

 1 struct file_operations {
 2     struct module *owner;
 3     loff_t (*llseek) (struct file *, loff_t, int);
 4     ssize_t (*read) (struct file *, char __user *, size_t, loff_t *);
 5     ssize_t (*write) (struct file *, const char __user *, size_t, loff_t *);
 6     ssize_t (*aio_read) (struct kiocb *, const struct iovec *, unsigned long, loff_t);
 7     ssize_t (*aio_write) (struct kiocb *, const struct iovec *, unsigned long, loff_t);
 8     int (*readdir) (struct file *, void *, filldir_t);
 9     unsigned int (*poll) (struct file *, struct poll_table_struct *);
10     long (*unlocked_ioctl) (struct file *, unsigned int, unsigned long);
11     long (*compat_ioctl) (struct file *, unsigned int, unsigned long);
12     int (*mmap) (struct file *, struct vm_area_struct *);
13     int (*open) (struct inode *, struct file *);
14     int (*flush) (struct file *, fl_owner_t id);
15     int (*release) (struct inode *, struct file *);
16     int (*fsync) (struct file *, loff_t, loff_t, int datasync);
17     int (*aio_fsync) (struct kiocb *, int datasync);
18     int (*fasync) (int, struct file *, int);
19     int (*lock) (struct file *, int, struct file_lock *);
20     ssize_t (*sendpage) (struct file *, struct page *, int, size_t, loff_t *, int);
21     unsigned long (*get_unmapped_area)(struct file *, unsigned long, unsigned long, unsigned long, unsigned long);
22     int (*check_flags)(int);
23     int (*flock) (struct file *, int, struct file_lock *);
24     ssize_t (*splice_write)(struct pipe_inode_info *, struct file *, loff_t *, size_t, unsigned int);
25     ssize_t (*splice_read)(struct file *, loff_t *, struct pipe_inode_info *, size_t, unsigned int);
26     int (*setlease)(struct file *, long, struct file_lock **);
27     long (*fallocate)(struct file *file, int mode, loff_t offset,
28               loff_t len);
29     int (*show_fdinfo)(struct seq_file *m, struct file *f);
30 };

linux3.10 file_operations

 1 struct file_operations {
 2     struct module *owner;
 3     loff_t (*llseek) (struct file *, loff_t, int);
 4     ssize_t (*read) (struct file *, char __user *, size_t, loff_t *);
 5     ssize_t (*write) (struct file *, const char __user *, size_t, loff_t *);
 6     ssize_t (*aio_read) (struct kiocb *, const struct iovec *, unsigned long, loff_t);
 7     ssize_t (*aio_write) (struct kiocb *, const struct iovec *, unsigned long, loff_t);
 8     int (*readdir) (struct file *, void *, filldir_t);
 9     unsigned int (*poll) (struct file *, struct poll_table_struct *);
10     int (*ioctl) (struct inode *, struct file *, unsigned int, unsigned long);
11     long (*unlocked_ioctl) (struct file *, unsigned int, unsigned long);
12     long (*compat_ioctl) (struct file *, unsigned int, unsigned long);
13     int (*mmap) (struct file *, struct vm_area_struct *);
14     int (*open) (struct inode *, struct file *);
15     int (*flush) (struct file *, fl_owner_t id);
16     int (*release) (struct inode *, struct file *);
17     int (*fsync) (struct file *, struct dentry *, int datasync);
18     int (*aio_fsync) (struct kiocb *, int datasync);
19     int (*fasync) (int, struct file *, int);
20     int (*lock) (struct file *, int, struct file_lock *);
21     ssize_t (*sendfile) (struct file *, loff_t *, size_t, read_actor_t, void *);
22     ssize_t (*sendpage) (struct file *, struct page *, int, size_t, loff_t *, int);
23     unsigned long (*get_unmapped_area)(struct file *, unsigned long, unsigned long, unsigned long, unsigned long);
24     int (*check_flags)(int);
25     int (*dir_notify)(struct file *filp, unsigned long arg);
26     int (*flock) (struct file *, int, struct file_lock *);
27     ssize_t (*splice_write)(struct pipe_inode_info *, struct file *, loff_t *, size_t, unsigned int);
28     ssize_t (*splice_read)(struct file *, loff_t *, struct pipe_inode_info *, size_t, unsigned int);
29 };

linux2.6.22 file_operation

在file_operation 赋值处修改：
.unlocked_ioctl = xxx_ioctl

此处需注意ioctl与unlocked_ioctl函数原型的差异，否则会造成传入的cmd改变。

2、调试用到的Makefile

 1 #KEVERS = $(shell uname -r)
 2 
 3 #kernel path 配置过的
 4 KEVERS := /home/liupf/work/linux-3.10.x
 5 INCS := -I$(KEVERS)
 6 #Kernel modules
 7 obj-m += memdev.o
 8 
 9 #EXTRA_CFAGS=-g -O0
10 
11 kernel_modules:
12     make -C $(KEVERS) M=$(CURDIR) modules
13     
14 test:
15     #arm-linux-gcc -O2 test_can.c -o test_can 
16     #Ubuntu kernel is 3.13  $(INCS)
17     arm-none-linux-gnueabi-gcc  app-ioctl.c -o ioctl.out
18 clean:
19     make -C $(KEVERS) M=$(CURDIR) clean

Makefile

3、调试用的脚本

1 #install.sh
2 rm -f /dev/memdev0
3 rmmod memdev.ko
4 insmod memdev.ko
5 mknod /dev/memdev0 c 251 0

install.sh

网上找的版本，待修改，不能直接用

 1 #!/bin/sh
 2 # install_mod.sh
 3 module="memdev"
 4 device="memdev"
 5 mode="664"
 6  
 7 # Group: since distributions do it differently, look for wheel or use staff
 8 if grep ‘^staff:‘ /etc/group > /dev/null; then
 9     group="staff"
10 else
11     group="kong"
12 fi
13  
14 # remove stale nodes
15 rm -f /dev/${device}?
16  
17 # invoke insmod with all arguments we got
18 # and use a pathname, as newer modutils don‘t look in . by default
19 /sbin/insmod -f ./$module.ko $* || exit 1
20  
21 major=`cat /proc/devices | awk "\\$2==\"$module\" {print \\$1}"`
22  
23 mknod /dev/${device}0 c $major 0
24 mknod /dev/${device}1 c $major 1
25 ln -sf ${device}0  /dev/${device}
26  
27 # give appropriate group/permissions
28 chgrp $group /dev/${device}[0-1]
29 chmod $mode  /dev/${device}[0-1]

install_mod.sh

 1 #!/bin/sh
 2 # uninstall_mod.sh
 3 module="memdev"
 4 device="memdev"
 5 
 6 # invoke rmmod with all arguments we got
 7 /sbin/rmmod $module $* || exit 1
 8 
 9 # Remove stale nodes
10 rm -f /dev/${device}0

uninstall_mod.sh

 

linux驱动简单实例:

https://blog.csdn.net/yangjin_unique/article/details/8217104