08582d678f
Overlayfs uses backing files with "fake" overlayfs f_path and "real" underlying f_inode, in order to use underlying inode aops for mapped files and to display the overlayfs path in /proc/<pid>/maps. In preparation for storing the overlayfs "fake" path instead of the underlying "real" path in struct backing_file, define a noop helper file_user_path() that returns f_path for now. Use the new helper in procfs and kernel logs whenever a path of a mapped file is displayed to users. Signed-off-by: Amir Goldstein <amir73il@gmail.com> Link: https://lore.kernel.org/r/20231009153712.1566422-3-amir73il@gmail.com Signed-off-by: Christian Brauner <brauner@kernel.org>
117 lines
2.6 KiB
C
117 lines
2.6 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
|
|
/* nommu.c: mmu-less memory info files
|
|
*
|
|
* Copyright (C) 2004 Red Hat, Inc. All Rights Reserved.
|
|
* Written by David Howells (dhowells@redhat.com)
|
|
*/
|
|
|
|
#include <linux/init.h>
|
|
#include <linux/module.h>
|
|
#include <linux/errno.h>
|
|
#include <linux/time.h>
|
|
#include <linux/kernel.h>
|
|
#include <linux/string.h>
|
|
#include <linux/mman.h>
|
|
#include <linux/proc_fs.h>
|
|
#include <linux/mm.h>
|
|
#include <linux/mmzone.h>
|
|
#include <linux/pagemap.h>
|
|
#include <linux/swap.h>
|
|
#include <linux/smp.h>
|
|
#include <linux/seq_file.h>
|
|
#include <linux/hugetlb.h>
|
|
#include <linux/vmalloc.h>
|
|
#include <asm/tlb.h>
|
|
#include <asm/div64.h>
|
|
#include "internal.h"
|
|
|
|
/*
|
|
* display a single region to a sequenced file
|
|
*/
|
|
static int nommu_region_show(struct seq_file *m, struct vm_region *region)
|
|
{
|
|
unsigned long ino = 0;
|
|
struct file *file;
|
|
dev_t dev = 0;
|
|
int flags;
|
|
|
|
flags = region->vm_flags;
|
|
file = region->vm_file;
|
|
|
|
if (file) {
|
|
struct inode *inode = file_inode(region->vm_file);
|
|
dev = inode->i_sb->s_dev;
|
|
ino = inode->i_ino;
|
|
}
|
|
|
|
seq_setwidth(m, 25 + sizeof(void *) * 6 - 1);
|
|
seq_printf(m,
|
|
"%08lx-%08lx %c%c%c%c %08llx %02x:%02x %lu ",
|
|
region->vm_start,
|
|
region->vm_end,
|
|
flags & VM_READ ? 'r' : '-',
|
|
flags & VM_WRITE ? 'w' : '-',
|
|
flags & VM_EXEC ? 'x' : '-',
|
|
flags & VM_MAYSHARE ? flags & VM_SHARED ? 'S' : 's' : 'p',
|
|
((loff_t)region->vm_pgoff) << PAGE_SHIFT,
|
|
MAJOR(dev), MINOR(dev), ino);
|
|
|
|
if (file) {
|
|
seq_pad(m, ' ');
|
|
seq_path(m, file_user_path(file), "");
|
|
}
|
|
|
|
seq_putc(m, '\n');
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* display a list of all the REGIONs the kernel knows about
|
|
* - nommu kernels have a single flat list
|
|
*/
|
|
static int nommu_region_list_show(struct seq_file *m, void *_p)
|
|
{
|
|
struct rb_node *p = _p;
|
|
|
|
return nommu_region_show(m, rb_entry(p, struct vm_region, vm_rb));
|
|
}
|
|
|
|
static void *nommu_region_list_start(struct seq_file *m, loff_t *_pos)
|
|
{
|
|
struct rb_node *p;
|
|
loff_t pos = *_pos;
|
|
|
|
down_read(&nommu_region_sem);
|
|
|
|
for (p = rb_first(&nommu_region_tree); p; p = rb_next(p))
|
|
if (pos-- == 0)
|
|
return p;
|
|
return NULL;
|
|
}
|
|
|
|
static void nommu_region_list_stop(struct seq_file *m, void *v)
|
|
{
|
|
up_read(&nommu_region_sem);
|
|
}
|
|
|
|
static void *nommu_region_list_next(struct seq_file *m, void *v, loff_t *pos)
|
|
{
|
|
(*pos)++;
|
|
return rb_next((struct rb_node *) v);
|
|
}
|
|
|
|
static const struct seq_operations proc_nommu_region_list_seqop = {
|
|
.start = nommu_region_list_start,
|
|
.next = nommu_region_list_next,
|
|
.stop = nommu_region_list_stop,
|
|
.show = nommu_region_list_show
|
|
};
|
|
|
|
static int __init proc_nommu_init(void)
|
|
{
|
|
proc_create_seq("maps", S_IRUGO, NULL, &proc_nommu_region_list_seqop);
|
|
return 0;
|
|
}
|
|
|
|
fs_initcall(proc_nommu_init);
|