__copy_to_user

__copy_to_user_inatomic
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Name

__copy_to_user_inatomic — Copy a block of data into user space, with less checking.

Synopsis

`unsigned long __must_check __copy_to_user_inatomic (`	void __user *	`to`,
	const void *	`from`,
	unsigned long	`n)`;

Arguments

to: Destination address, in user space.
from: Source address, in kernel space.
n: Number of bytes to copy.

Context

User context only.

Description

Copy data from kernel space to user space. Caller must check the specified block with access_ok before calling this function. The caller should also make sure he pins the user space address so that the we don't result in page fault and sleep.

Here we special-case 1, 2 and 4-byte copy_*_user invocations. On a fault we return the initial request size (1, 2 or 4), as copy_*_user should do. If a store crosses a page boundary and gets a fault, the x86 will not write anything, so this is accurate.