Webstatic inline int __kfifo_from_user_data (struct kfifo *fifo, const void __user *from, unsigned int len, unsigned int off, unsigned *lenout) { unsigned int l; int ret; /* * Ensure that we sample the fifo->out index -before- we * start putting bytes into the kfifo. */ smp_mb (); off = __kfifo_off (fifo, fifo->in + off); Web11 apr. 2024 · kfifo_from_user () 是把from指向的用户空间的len个数据元素复制到KFIFO …
Linux内核kfifo - 裸睡的猪 - 博客园
Web很明显,第一个问号才是问题,后面两个都是补充。. 他问:“为什么要把参数从用户空间拷贝到内核空间”,而不是“直接访问”,或者用“memcpy"来访问,却要”用copy_from_user"访问。. 这三个问号明显是一体的。. 问的就是如果我用比如ioctl (fd, cmd, arg)做系统 ... Webkfifo.h - include/linux/kfifo.h - Linux source code (v5.19) - Bootlin Elixir Cross Referencer … can i purchase word by itself
mkfifo - The Open Group
Webkfifo_from_user - puts some data from user space into the fifo SYNOPSIS ¶ kfifo_from_user (fifo, from, len, copied); ARGUMENTS ¶ fifo address of the fifo to be used from pointer to the data to be added len the length of the data to be added copied pointer to output variable to store the number of copied bytes DESCRIPTION ¶ WebThe c++ (cpp) kfifo_from_user example is extracted from the most popular open source … Webkfifo_from_user()是把from指向的用户空间的len个数据元素复制到KFIFO中,最后一个参数copied表示成功复制了几个数据元素。 kfifo_to_user()则相反,把KFIFO的数据元素复制到用户空间。这两个宏结合了copy_to_user()、copy_from_user()以及KFIFO的机制,给驱动开发者提供了方便。 five importance of food safety