请教copy_to_user的用法

applepie · 发表于 2003-5-26 19:46:41

我接着"请教设备驱动程序"问:

[code:1]
char *words="aaabbbccc";

ssize_t scull_read(struct file *filp, char *buf, size_t count,
loff_t *f_pos)
{
printk("read %s\n",words);

copy_to_user(buf,words,count);
return 0;
}
[/code:1]

这里 copy_to_user 不知道咋用
copy_to_user(buf,words,count); 是我想当然的写的

编译通过后
#insmod chard.o
chard.o: unresolved symbol copy_to_user

请指教

Dragonfly · 发表于 2003-5-26 22:02:52

u should include <asm/uaccess.h>
read LDD2 for detail. i bet the book has this.

applepie · 发表于 2003-5-26 22:37:20

谢谢
原来我没有 include

Dragonfly · 发表于 2003-5-26 22:42:54

make sure u read LDD2 Page 78-79 carefully.

applepie · 发表于 2003-5-27 12:42:00

我还没这本书呢

Dragonfly · 发表于 2003-5-27 21:25:12

there is an e version online for freely download from its publisher site. i think is oriley..

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