mirror of
https://github.com/team-infusion-developers/android_kernel_samsung_msm8976.git
synced 2024-10-31 18:09:19 +00:00
582 lines
14 KiB
C
582 lines
14 KiB
C
|
/*
|
||
|
* linux/mm/filemap_xip.c
|
||
|
*
|
||
|
* Copyright (C) 2005 IBM Corporation
|
||
|
* Author: Carsten Otte <cotte@de.ibm.com>
|
||
|
*
|
||
|
* derived from linux/mm/filemap.c - Copyright (C) Linus Torvalds
|
||
|
*
|
||
|
*/
|
||
|
|
||
|
#include <linux/fs.h>
|
||
|
#include <linux/pagemap.h>
|
||
|
#include <linux/module.h>
|
||
|
#include <linux/uio.h>
|
||
|
#include <linux/rmap.h>
|
||
|
#include <asm/tlbflush.h>
|
||
|
#include "filemap.h"
|
||
|
|
||
|
/*
|
||
|
* This is a file read routine for execute in place files, and uses
|
||
|
* the mapping->a_ops->get_xip_page() function for the actual low-level
|
||
|
* stuff.
|
||
|
*
|
||
|
* Note the struct file* is not used at all. It may be NULL.
|
||
|
*/
|
||
|
static void
|
||
|
do_xip_mapping_read(struct address_space *mapping,
|
||
|
struct file_ra_state *_ra,
|
||
|
struct file *filp,
|
||
|
loff_t *ppos,
|
||
|
read_descriptor_t *desc,
|
||
|
read_actor_t actor)
|
||
|
{
|
||
|
struct inode *inode = mapping->host;
|
||
|
unsigned long index, end_index, offset;
|
||
|
loff_t isize;
|
||
|
|
||
|
BUG_ON(!mapping->a_ops->get_xip_page);
|
||
|
|
||
|
index = *ppos >> PAGE_CACHE_SHIFT;
|
||
|
offset = *ppos & ~PAGE_CACHE_MASK;
|
||
|
|
||
|
isize = i_size_read(inode);
|
||
|
if (!isize)
|
||
|
goto out;
|
||
|
|
||
|
end_index = (isize - 1) >> PAGE_CACHE_SHIFT;
|
||
|
for (;;) {
|
||
|
struct page *page;
|
||
|
unsigned long nr, ret;
|
||
|
|
||
|
/* nr is the maximum number of bytes to copy from this page */
|
||
|
nr = PAGE_CACHE_SIZE;
|
||
|
if (index >= end_index) {
|
||
|
if (index > end_index)
|
||
|
goto out;
|
||
|
nr = ((isize - 1) & ~PAGE_CACHE_MASK) + 1;
|
||
|
if (nr <= offset) {
|
||
|
goto out;
|
||
|
}
|
||
|
}
|
||
|
nr = nr - offset;
|
||
|
|
||
|
page = mapping->a_ops->get_xip_page(mapping,
|
||
|
index*(PAGE_SIZE/512), 0);
|
||
|
if (!page)
|
||
|
goto no_xip_page;
|
||
|
if (unlikely(IS_ERR(page))) {
|
||
|
if (PTR_ERR(page) == -ENODATA) {
|
||
|
/* sparse */
|
||
|
page = virt_to_page(empty_zero_page);
|
||
|
} else {
|
||
|
desc->error = PTR_ERR(page);
|
||
|
goto out;
|
||
|
}
|
||
|
} else
|
||
|
BUG_ON(!PageUptodate(page));
|
||
|
|
||
|
/* If users can be writing to this page using arbitrary
|
||
|
* virtual addresses, take care about potential aliasing
|
||
|
* before reading the page on the kernel side.
|
||
|
*/
|
||
|
if (mapping_writably_mapped(mapping))
|
||
|
flush_dcache_page(page);
|
||
|
|
||
|
/*
|
||
|
* Ok, we have the page, and it's up-to-date, so
|
||
|
* now we can copy it to user space...
|
||
|
*
|
||
|
* The actor routine returns how many bytes were actually used..
|
||
|
* NOTE! This may not be the same as how much of a user buffer
|
||
|
* we filled up (we may be padding etc), so we can only update
|
||
|
* "pos" here (the actor routine has to update the user buffer
|
||
|
* pointers and the remaining count).
|
||
|
*/
|
||
|
ret = actor(desc, page, offset, nr);
|
||
|
offset += ret;
|
||
|
index += offset >> PAGE_CACHE_SHIFT;
|
||
|
offset &= ~PAGE_CACHE_MASK;
|
||
|
|
||
|
if (ret == nr && desc->count)
|
||
|
continue;
|
||
|
goto out;
|
||
|
|
||
|
no_xip_page:
|
||
|
/* Did not get the page. Report it */
|
||
|
desc->error = -EIO;
|
||
|
goto out;
|
||
|
}
|
||
|
|
||
|
out:
|
||
|
*ppos = ((loff_t) index << PAGE_CACHE_SHIFT) + offset;
|
||
|
if (filp)
|
||
|
file_accessed(filp);
|
||
|
}
|
||
|
|
||
|
/*
|
||
|
* This is the "read()" routine for all filesystems
|
||
|
* that uses the get_xip_page address space operation.
|
||
|
*/
|
||
|
static ssize_t
|
||
|
__xip_file_aio_read(struct kiocb *iocb, const struct iovec *iov,
|
||
|
unsigned long nr_segs, loff_t *ppos)
|
||
|
{
|
||
|
struct file *filp = iocb->ki_filp;
|
||
|
ssize_t retval;
|
||
|
unsigned long seg;
|
||
|
size_t count;
|
||
|
|
||
|
count = 0;
|
||
|
for (seg = 0; seg < nr_segs; seg++) {
|
||
|
const struct iovec *iv = &iov[seg];
|
||
|
|
||
|
/*
|
||
|
* If any segment has a negative length, or the cumulative
|
||
|
* length ever wraps negative then return -EINVAL.
|
||
|
*/
|
||
|
count += iv->iov_len;
|
||
|
if (unlikely((ssize_t)(count|iv->iov_len) < 0))
|
||
|
return -EINVAL;
|
||
|
if (access_ok(VERIFY_WRITE, iv->iov_base, iv->iov_len))
|
||
|
continue;
|
||
|
if (seg == 0)
|
||
|
return -EFAULT;
|
||
|
nr_segs = seg;
|
||
|
count -= iv->iov_len; /* This segment is no good */
|
||
|
break;
|
||
|
}
|
||
|
|
||
|
retval = 0;
|
||
|
if (count) {
|
||
|
for (seg = 0; seg < nr_segs; seg++) {
|
||
|
read_descriptor_t desc;
|
||
|
|
||
|
desc.written = 0;
|
||
|
desc.arg.buf = iov[seg].iov_base;
|
||
|
desc.count = iov[seg].iov_len;
|
||
|
if (desc.count == 0)
|
||
|
continue;
|
||
|
desc.error = 0;
|
||
|
do_xip_mapping_read(filp->f_mapping, &filp->f_ra, filp,
|
||
|
ppos, &desc, file_read_actor);
|
||
|
retval += desc.written;
|
||
|
if (!retval) {
|
||
|
retval = desc.error;
|
||
|
break;
|
||
|
}
|
||
|
}
|
||
|
}
|
||
|
return retval;
|
||
|
}
|
||
|
|
||
|
ssize_t
|
||
|
xip_file_aio_read(struct kiocb *iocb, char __user *buf, size_t count,
|
||
|
loff_t pos)
|
||
|
{
|
||
|
struct iovec local_iov = { .iov_base = buf, .iov_len = count };
|
||
|
|
||
|
BUG_ON(iocb->ki_pos != pos);
|
||
|
return __xip_file_aio_read(iocb, &local_iov, 1, &iocb->ki_pos);
|
||
|
}
|
||
|
EXPORT_SYMBOL_GPL(xip_file_aio_read);
|
||
|
|
||
|
ssize_t
|
||
|
xip_file_readv(struct file *filp, const struct iovec *iov,
|
||
|
unsigned long nr_segs, loff_t *ppos)
|
||
|
{
|
||
|
struct kiocb kiocb;
|
||
|
|
||
|
init_sync_kiocb(&kiocb, filp);
|
||
|
return __xip_file_aio_read(&kiocb, iov, nr_segs, ppos);
|
||
|
}
|
||
|
EXPORT_SYMBOL_GPL(xip_file_readv);
|
||
|
|
||
|
ssize_t
|
||
|
xip_file_sendfile(struct file *in_file, loff_t *ppos,
|
||
|
size_t count, read_actor_t actor, void *target)
|
||
|
{
|
||
|
read_descriptor_t desc;
|
||
|
|
||
|
if (!count)
|
||
|
return 0;
|
||
|
|
||
|
desc.written = 0;
|
||
|
desc.count = count;
|
||
|
desc.arg.data = target;
|
||
|
desc.error = 0;
|
||
|
|
||
|
do_xip_mapping_read(in_file->f_mapping, &in_file->f_ra, in_file,
|
||
|
ppos, &desc, actor);
|
||
|
if (desc.written)
|
||
|
return desc.written;
|
||
|
return desc.error;
|
||
|
}
|
||
|
EXPORT_SYMBOL_GPL(xip_file_sendfile);
|
||
|
|
||
|
/*
|
||
|
* __xip_unmap is invoked from xip_unmap and
|
||
|
* xip_write
|
||
|
*
|
||
|
* This function walks all vmas of the address_space and unmaps the
|
||
|
* empty_zero_page when found at pgoff. Should it go in rmap.c?
|
||
|
*/
|
||
|
static void
|
||
|
__xip_unmap (struct address_space * mapping,
|
||
|
unsigned long pgoff)
|
||
|
{
|
||
|
struct vm_area_struct *vma;
|
||
|
struct mm_struct *mm;
|
||
|
struct prio_tree_iter iter;
|
||
|
unsigned long address;
|
||
|
pte_t *pte;
|
||
|
pte_t pteval;
|
||
|
|
||
|
spin_lock(&mapping->i_mmap_lock);
|
||
|
vma_prio_tree_foreach(vma, &iter, &mapping->i_mmap, pgoff, pgoff) {
|
||
|
mm = vma->vm_mm;
|
||
|
address = vma->vm_start +
|
||
|
((pgoff - vma->vm_pgoff) << PAGE_SHIFT);
|
||
|
BUG_ON(address < vma->vm_start || address >= vma->vm_end);
|
||
|
/*
|
||
|
* We need the page_table_lock to protect us from page faults,
|
||
|
* munmap, fork, etc...
|
||
|
*/
|
||
|
pte = page_check_address(virt_to_page(empty_zero_page), mm,
|
||
|
address);
|
||
|
if (!IS_ERR(pte)) {
|
||
|
/* Nuke the page table entry. */
|
||
|
flush_cache_page(vma, address, pte_pfn(pte));
|
||
|
pteval = ptep_clear_flush(vma, address, pte);
|
||
|
BUG_ON(pte_dirty(pteval));
|
||
|
pte_unmap(pte);
|
||
|
spin_unlock(&mm->page_table_lock);
|
||
|
}
|
||
|
}
|
||
|
spin_unlock(&mapping->i_mmap_lock);
|
||
|
}
|
||
|
|
||
|
/*
|
||
|
* xip_nopage() is invoked via the vma operations vector for a
|
||
|
* mapped memory region to read in file data during a page fault.
|
||
|
*
|
||
|
* This function is derived from filemap_nopage, but used for execute in place
|
||
|
*/
|
||
|
static struct page *
|
||
|
xip_file_nopage(struct vm_area_struct * area,
|
||
|
unsigned long address,
|
||
|
int *type)
|
||
|
{
|
||
|
struct file *file = area->vm_file;
|
||
|
struct address_space *mapping = file->f_mapping;
|
||
|
struct inode *inode = mapping->host;
|
||
|
struct page *page;
|
||
|
unsigned long size, pgoff, endoff;
|
||
|
|
||
|
pgoff = ((address - area->vm_start) >> PAGE_CACHE_SHIFT)
|
||
|
+ area->vm_pgoff;
|
||
|
endoff = ((area->vm_end - area->vm_start) >> PAGE_CACHE_SHIFT)
|
||
|
+ area->vm_pgoff;
|
||
|
|
||
|
size = (i_size_read(inode) + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
|
||
|
if (pgoff >= size) {
|
||
|
return NULL;
|
||
|
}
|
||
|
|
||
|
page = mapping->a_ops->get_xip_page(mapping, pgoff*(PAGE_SIZE/512), 0);
|
||
|
if (!IS_ERR(page)) {
|
||
|
BUG_ON(!PageUptodate(page));
|
||
|
return page;
|
||
|
}
|
||
|
if (PTR_ERR(page) != -ENODATA)
|
||
|
return NULL;
|
||
|
|
||
|
/* sparse block */
|
||
|
if ((area->vm_flags & (VM_WRITE | VM_MAYWRITE)) &&
|
||
|
(area->vm_flags & (VM_SHARED| VM_MAYSHARE)) &&
|
||
|
(!(mapping->host->i_sb->s_flags & MS_RDONLY))) {
|
||
|
/* maybe shared writable, allocate new block */
|
||
|
page = mapping->a_ops->get_xip_page (mapping,
|
||
|
pgoff*(PAGE_SIZE/512), 1);
|
||
|
if (IS_ERR(page))
|
||
|
return NULL;
|
||
|
BUG_ON(!PageUptodate(page));
|
||
|
/* unmap page at pgoff from all other vmas */
|
||
|
__xip_unmap(mapping, pgoff);
|
||
|
} else {
|
||
|
/* not shared and writable, use empty_zero_page */
|
||
|
page = virt_to_page(empty_zero_page);
|
||
|
}
|
||
|
|
||
|
return page;
|
||
|
}
|
||
|
|
||
|
static struct vm_operations_struct xip_file_vm_ops = {
|
||
|
.nopage = xip_file_nopage,
|
||
|
};
|
||
|
|
||
|
int xip_file_mmap(struct file * file, struct vm_area_struct * vma)
|
||
|
{
|
||
|
BUG_ON(!file->f_mapping->a_ops->get_xip_page);
|
||
|
|
||
|
file_accessed(file);
|
||
|
vma->vm_ops = &xip_file_vm_ops;
|
||
|
return 0;
|
||
|
}
|
||
|
EXPORT_SYMBOL_GPL(xip_file_mmap);
|
||
|
|
||
|
static ssize_t
|
||
|
do_xip_file_write(struct kiocb *iocb, const struct iovec *iov,
|
||
|
unsigned long nr_segs, loff_t pos, loff_t *ppos,
|
||
|
size_t count)
|
||
|
{
|
||
|
struct file *file = iocb->ki_filp;
|
||
|
struct address_space * mapping = file->f_mapping;
|
||
|
struct address_space_operations *a_ops = mapping->a_ops;
|
||
|
struct inode *inode = mapping->host;
|
||
|
long status = 0;
|
||
|
struct page *page;
|
||
|
size_t bytes;
|
||
|
const struct iovec *cur_iov = iov; /* current iovec */
|
||
|
size_t iov_base = 0; /* offset in the current iovec */
|
||
|
char __user *buf;
|
||
|
ssize_t written = 0;
|
||
|
|
||
|
BUG_ON(!mapping->a_ops->get_xip_page);
|
||
|
|
||
|
buf = iov->iov_base;
|
||
|
do {
|
||
|
unsigned long index;
|
||
|
unsigned long offset;
|
||
|
size_t copied;
|
||
|
|
||
|
offset = (pos & (PAGE_CACHE_SIZE -1)); /* Within page */
|
||
|
index = pos >> PAGE_CACHE_SHIFT;
|
||
|
bytes = PAGE_CACHE_SIZE - offset;
|
||
|
if (bytes > count)
|
||
|
bytes = count;
|
||
|
|
||
|
/*
|
||
|
* Bring in the user page that we will copy from _first_.
|
||
|
* Otherwise there's a nasty deadlock on copying from the
|
||
|
* same page as we're writing to, without it being marked
|
||
|
* up-to-date.
|
||
|
*/
|
||
|
fault_in_pages_readable(buf, bytes);
|
||
|
|
||
|
page = a_ops->get_xip_page(mapping,
|
||
|
index*(PAGE_SIZE/512), 0);
|
||
|
if (IS_ERR(page) && (PTR_ERR(page) == -ENODATA)) {
|
||
|
/* we allocate a new page unmap it */
|
||
|
page = a_ops->get_xip_page(mapping,
|
||
|
index*(PAGE_SIZE/512), 1);
|
||
|
if (!IS_ERR(page))
|
||
|
/* unmap page at pgoff from all other vmas */
|
||
|
__xip_unmap(mapping, index);
|
||
|
|
||
|
}
|
||
|
|
||
|
if (IS_ERR(page)) {
|
||
|
status = PTR_ERR(page);
|
||
|
break;
|
||
|
}
|
||
|
|
||
|
BUG_ON(!PageUptodate(page));
|
||
|
|
||
|
if (likely(nr_segs == 1))
|
||
|
copied = filemap_copy_from_user(page, offset,
|
||
|
buf, bytes);
|
||
|
else
|
||
|
copied = filemap_copy_from_user_iovec(page, offset,
|
||
|
cur_iov, iov_base, bytes);
|
||
|
flush_dcache_page(page);
|
||
|
if (likely(copied > 0)) {
|
||
|
status = copied;
|
||
|
|
||
|
if (status >= 0) {
|
||
|
written += status;
|
||
|
count -= status;
|
||
|
pos += status;
|
||
|
buf += status;
|
||
|
if (unlikely(nr_segs > 1))
|
||
|
filemap_set_next_iovec(&cur_iov,
|
||
|
&iov_base, status);
|
||
|
}
|
||
|
}
|
||
|
if (unlikely(copied != bytes))
|
||
|
if (status >= 0)
|
||
|
status = -EFAULT;
|
||
|
if (status < 0)
|
||
|
break;
|
||
|
} while (count);
|
||
|
*ppos = pos;
|
||
|
/*
|
||
|
* No need to use i_size_read() here, the i_size
|
||
|
* cannot change under us because we hold i_sem.
|
||
|
*/
|
||
|
if (pos > inode->i_size) {
|
||
|
i_size_write(inode, pos);
|
||
|
mark_inode_dirty(inode);
|
||
|
}
|
||
|
|
||
|
return written ? written : status;
|
||
|
}
|
||
|
|
||
|
static ssize_t
|
||
|
xip_file_aio_write_nolock(struct kiocb *iocb, const struct iovec *iov,
|
||
|
unsigned long nr_segs, loff_t *ppos)
|
||
|
{
|
||
|
struct file *file = iocb->ki_filp;
|
||
|
struct address_space * mapping = file->f_mapping;
|
||
|
size_t ocount; /* original count */
|
||
|
size_t count; /* after file limit checks */
|
||
|
struct inode *inode = mapping->host;
|
||
|
unsigned long seg;
|
||
|
loff_t pos;
|
||
|
ssize_t written;
|
||
|
ssize_t err;
|
||
|
|
||
|
ocount = 0;
|
||
|
for (seg = 0; seg < nr_segs; seg++) {
|
||
|
const struct iovec *iv = &iov[seg];
|
||
|
|
||
|
/*
|
||
|
* If any segment has a negative length, or the cumulative
|
||
|
* length ever wraps negative then return -EINVAL.
|
||
|
*/
|
||
|
ocount += iv->iov_len;
|
||
|
if (unlikely((ssize_t)(ocount|iv->iov_len) < 0))
|
||
|
return -EINVAL;
|
||
|
if (access_ok(VERIFY_READ, iv->iov_base, iv->iov_len))
|
||
|
continue;
|
||
|
if (seg == 0)
|
||
|
return -EFAULT;
|
||
|
nr_segs = seg;
|
||
|
ocount -= iv->iov_len; /* This segment is no good */
|
||
|
break;
|
||
|
}
|
||
|
|
||
|
count = ocount;
|
||
|
pos = *ppos;
|
||
|
|
||
|
vfs_check_frozen(inode->i_sb, SB_FREEZE_WRITE);
|
||
|
|
||
|
written = 0;
|
||
|
|
||
|
err = generic_write_checks(file, &pos, &count, S_ISBLK(inode->i_mode));
|
||
|
if (err)
|
||
|
goto out;
|
||
|
|
||
|
if (count == 0)
|
||
|
goto out;
|
||
|
|
||
|
err = remove_suid(file->f_dentry);
|
||
|
if (err)
|
||
|
goto out;
|
||
|
|
||
|
inode_update_time(inode, 1);
|
||
|
|
||
|
/* use execute in place to copy directly to disk */
|
||
|
written = do_xip_file_write (iocb, iov,
|
||
|
nr_segs, pos, ppos, count);
|
||
|
out:
|
||
|
return written ? written : err;
|
||
|
}
|
||
|
|
||
|
static ssize_t
|
||
|
__xip_file_write_nolock(struct file *file, const struct iovec *iov,
|
||
|
unsigned long nr_segs, loff_t *ppos)
|
||
|
{
|
||
|
struct kiocb kiocb;
|
||
|
|
||
|
init_sync_kiocb(&kiocb, file);
|
||
|
return xip_file_aio_write_nolock(&kiocb, iov, nr_segs, ppos);
|
||
|
}
|
||
|
|
||
|
ssize_t
|
||
|
xip_file_aio_write(struct kiocb *iocb, const char __user *buf,
|
||
|
size_t count, loff_t pos)
|
||
|
{
|
||
|
struct file *file = iocb->ki_filp;
|
||
|
struct address_space *mapping = file->f_mapping;
|
||
|
struct inode *inode = mapping->host;
|
||
|
ssize_t ret;
|
||
|
struct iovec local_iov = { .iov_base = (void __user *)buf,
|
||
|
.iov_len = count };
|
||
|
|
||
|
BUG_ON(iocb->ki_pos != pos);
|
||
|
|
||
|
down(&inode->i_sem);
|
||
|
ret = xip_file_aio_write_nolock(iocb, &local_iov, 1, &iocb->ki_pos);
|
||
|
up(&inode->i_sem);
|
||
|
return ret;
|
||
|
}
|
||
|
EXPORT_SYMBOL_GPL(xip_file_aio_write);
|
||
|
|
||
|
ssize_t xip_file_writev(struct file *file, const struct iovec *iov,
|
||
|
unsigned long nr_segs, loff_t *ppos)
|
||
|
{
|
||
|
struct address_space *mapping = file->f_mapping;
|
||
|
struct inode *inode = mapping->host;
|
||
|
ssize_t ret;
|
||
|
|
||
|
down(&inode->i_sem);
|
||
|
ret = __xip_file_write_nolock(file, iov, nr_segs, ppos);
|
||
|
up(&inode->i_sem);
|
||
|
return ret;
|
||
|
}
|
||
|
EXPORT_SYMBOL_GPL(xip_file_writev);
|
||
|
|
||
|
/*
|
||
|
* truncate a page used for execute in place
|
||
|
* functionality is analog to block_truncate_page but does use get_xip_page
|
||
|
* to get the page instead of page cache
|
||
|
*/
|
||
|
int
|
||
|
xip_truncate_page(struct address_space *mapping, loff_t from)
|
||
|
{
|
||
|
pgoff_t index = from >> PAGE_CACHE_SHIFT;
|
||
|
unsigned offset = from & (PAGE_CACHE_SIZE-1);
|
||
|
unsigned blocksize;
|
||
|
unsigned length;
|
||
|
struct page *page;
|
||
|
void *kaddr;
|
||
|
int err;
|
||
|
|
||
|
BUG_ON(!mapping->a_ops->get_xip_page);
|
||
|
|
||
|
blocksize = 1 << mapping->host->i_blkbits;
|
||
|
length = offset & (blocksize - 1);
|
||
|
|
||
|
/* Block boundary? Nothing to do */
|
||
|
if (!length)
|
||
|
return 0;
|
||
|
|
||
|
length = blocksize - length;
|
||
|
|
||
|
page = mapping->a_ops->get_xip_page(mapping,
|
||
|
index*(PAGE_SIZE/512), 0);
|
||
|
err = -ENOMEM;
|
||
|
if (!page)
|
||
|
goto out;
|
||
|
if (unlikely(IS_ERR(page))) {
|
||
|
if (PTR_ERR(page) == -ENODATA) {
|
||
|
/* Hole? No need to truncate */
|
||
|
return 0;
|
||
|
} else {
|
||
|
err = PTR_ERR(page);
|
||
|
goto out;
|
||
|
}
|
||
|
} else
|
||
|
BUG_ON(!PageUptodate(page));
|
||
|
kaddr = kmap_atomic(page, KM_USER0);
|
||
|
memset(kaddr + offset, 0, length);
|
||
|
kunmap_atomic(kaddr, KM_USER0);
|
||
|
|
||
|
flush_dcache_page(page);
|
||
|
err = 0;
|
||
|
out:
|
||
|
return err;
|
||
|
}
|
||
|
EXPORT_SYMBOL_GPL(xip_truncate_page);
|