函数逻辑报告

Linux Kernel

v5.5.9

Brick Technologies Co., Ltd

Source Code:fs\read_write.c Create Date:2022-07-29 10:31:22
Last Modify:2020-03-18 10:18:51 Copyright©Brick
首页 函数Tree
注解内核,赢得工具下载SCCTEnglish

函数名称：vfs_read

函数原型：ssize_t vfs_read(struct file *file, char __user *buf, size_t count, loff_t *pos)

返回类型：ssize_t

参数：

类型参数名称
struct file *file
char __user *buf
size_tcount
loff_t *pos
450  如果非f_mode按位与le is open for reading 的值则返回:负EBADF
452  如果非f_mode按位与Has read method(s) 的值则返回:负EINVAL
454  如果此条件成立可能性小(为编译器优化)(!access_ok - Checks if a user space pointer is valid*@addr: User space pointer to start of block to check*@size: Size of block to check* Context: User context only. This function may sleep if pagefaults are* enabled.(buf, count))则返回:负EFAULT
457  ret等于rw_verify_area(generic data direction definitions , file, pos, count)
458  如果非ret则
459  如果count大于MAX_RW_COUNT则count等于MAX_RW_COUNT
461  ret等于__vfs_read(file, buf, count, pos)
462  如果ret大于0则
463  snotify_access - file was read
464  add_rchar(当前进程, ret)
466  inc_syscr(当前进程)
469  返回:ret
调用者
名称描述
kernel_read
ksys_read
ksys_pread64
read_code