'\" t
.\"     Title: vm_insert_page
.\"    Author: [FIXME: author] [see http://docbook.sf.net/el/author]
.\" Generator: DocBook XSL Stylesheets v1.78.1 <http://docbook.sf.net/>
.\"      Date: January 2017
.\"    Manual: Memory Management in Linux
.\"    Source: Kernel Hackers Manual 4.8.15
.\"  Language: English
.\"
.TH "VM_INSERT_PAGE" "9" "January 2017" "Kernel Hackers Manual 4\&.8\&." "Memory Management in Linux"
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.SH "NAME"
vm_insert_page \- insert single page into user vma
.SH "SYNOPSIS"
.HP \w'int\ vm_insert_page('u
.BI "int vm_insert_page(struct\ vm_area_struct\ *\ " "vma" ", unsigned\ long\ " "addr" ", struct\ page\ *\ " "page" ");"
.SH "ARGUMENTS"
.PP
\fIvma\fR
.RS 4
user vma to map to
.RE
.PP
\fIaddr\fR
.RS 4
target user address of this page
.RE
.PP
\fIpage\fR
.RS 4
source kernel page
.RE
.SH "DESCRIPTION"
.PP
This allows drivers to insert individual pages they\*(Aqve allocated into a user vma\&.
.PP
The page has to be a nice clean _individual_ kernel allocation\&. If you allocate a compound page, you need to have marked it as such (__GFP_COMP), or manually just split the page up yourself (see
\fBsplit_page\fR)\&.
.PP
NOTE! Traditionally this was done with
\(lq\fBremap_pfn_range\fR\(rq
which took an arbitrary page protection parameter\&. This doesn\*(Aqt allow that\&. Your vma protection will have to be set up correctly, which means that if you want a shared writable mapping, you\*(Aqd better ask for a shared writable mapping!
.PP
The page does not need to be reserved\&.
.PP
Usually this function is called from f_op\->\fBmmap\fR
handler under mm\->mmap_sem write\-lock, so it can change vma\->vm_flags\&. Caller must set VM_MIXEDMAP on vma if it wants to call this function from other places, for example from page\-fault handler\&.
.SH "COPYRIGHT"
.br