LXR linux/fs/proc/nommu.c

   1/* nommu.c: mmu-less memory info files
   2 *
   3 * Copyright (C) 2004 Red Hat, Inc. All Rights Reserved.
   4 * Written by David Howells (dhowells@redhat.com)
   5 *
   6 * This program is free software; you can redistribute it and/or
   7 * modify it under the terms of the GNU General Public License
   8 * as published by the Free Software Foundation; either version
   9 * 2 of the License, or (at your option) any later version.
  10 */
  11
  12#include <linux/init.h>
  13#include <linux/module.h>
  14#include <linux/errno.h>
  15#include <linux/time.h>
  16#include <linux/kernel.h>
  17#include <linux/string.h>
  18#include <linux/mman.h>
  19#include <linux/proc_fs.h>
  20#include <linux/mm.h>
  21#include <linux/mmzone.h>
  22#include <linux/pagemap.h>
  23#include <linux/swap.h>
  24#include <linux/slab.h>
  25#include <linux/smp.h>
  26#include <linux/seq_file.h>
  27#include <linux/hugetlb.h>
  28#include <linux/vmalloc.h>
  29#include <asm/uaccess.h>
  30#include <asm/pgtable.h>
  31#include <asm/tlb.h>
  32#include <asm/div64.h>
  33#include "internal.h"
  34
  35/*
  36 * display a single VMA to a sequenced file
  37 */
  38int nommu_vma_show(struct seq_file *m, struct vm_area_struct *vma)
  39{
  40        unsigned long ino = 0;
  41        struct file *file;
  42        dev_t dev = 0;
  43        int flags, len;
  44
  45        flags = vma->vm_flags;
  46        file = vma->vm_file;
  47
  48        if (file) {
  49                struct inode *inode = vma->vm_file->f_path.dentry->d_inode;
  50                dev = inode->i_sb->s_dev;
  51                ino = inode->i_ino;
  52        }
  53
  54        seq_printf(m,
  55                   "%08lx-%08lx %c%c%c%c %08llx %02x:%02x %lu %n",
  56                   vma->vm_start,
  57                   vma->vm_end,
  58                   flags & VM_READ ? 'r' : '-',
  59                   flags & VM_WRITE ? 'w' : '-',
  60                   flags & VM_EXEC ? 'x' : '-',
  61                   flags & VM_MAYSHARE ? flags & VM_SHARED ? 'S' : 's' : 'p',
  62                   ((loff_t)vma->vm_pgoff) << PAGE_SHIFT,
  63                   MAJOR(dev), MINOR(dev), ino, &len);
  64
  65        if (file) {
  66                len = 25 + sizeof(void *) * 6 - len;
  67                if (len < 1)
  68                        len = 1;
  69                seq_printf(m, "%*c", len, ' ');
  70                seq_path(m, &file->f_path, "");
  71        }
  72
  73        seq_putc(m, '\n');
  74        return 0;
  75}
  76
  77/*
  78 * display a list of all the VMAs the kernel knows about
  79 * - nommu kernals have a single flat list
  80 */
  81static int nommu_vma_list_show(struct seq_file *m, void *v)
  82{
  83        struct vm_area_struct *vma;
  84
  85        vma = rb_entry((struct rb_node *) v, struct vm_area_struct, vm_rb);
  86        return nommu_vma_show(m, vma);
  87}
  88
  89static void *nommu_vma_list_start(struct seq_file *m, loff_t *_pos)
  90{
  91        struct rb_node *_rb;
  92        loff_t pos = *_pos;
  93        void *next = NULL;
  94
  95        down_read(&nommu_vma_sem);
  96
  97        for (_rb = rb_first(&nommu_vma_tree); _rb; _rb = rb_next(_rb)) {
  98                if (pos == 0) {
  99                        next = _rb;
 100                        break;
 101                }
 102                pos--;
 103        }
 104
 105        return next;
 106}
 107
 108static void nommu_vma_list_stop(struct seq_file *m, void *v)
 109{
 110        up_read(&nommu_vma_sem);
 111}
 112
 113static void *nommu_vma_list_next(struct seq_file *m, void *v, loff_t *pos)
 114{
 115        (*pos)++;
 116        return rb_next((struct rb_node *) v);
 117}
 118
 119static const struct seq_operations proc_nommu_vma_list_seqop = {
 120        .start  = nommu_vma_list_start,
 121        .next   = nommu_vma_list_next,
 122        .stop   = nommu_vma_list_stop,
 123        .show   = nommu_vma_list_show
 124};
 125
 126static int proc_nommu_vma_list_open(struct inode *inode, struct file *file)
 127{
 128        return seq_open(file, &proc_nommu_vma_list_seqop);
 129}
 130
 131static const struct file_operations proc_nommu_vma_list_operations = {
 132        .open    = proc_nommu_vma_list_open,
 133        .read    = seq_read,
 134        .llseek  = seq_lseek,
 135        .release = seq_release,
 136};
 137
 138static int __init proc_nommu_init(void)
 139{
 140        proc_create("maps", S_IRUGO, NULL, &proc_nommu_vma_list_operations);
 141        return 0;
 142}
 143
 144module_init(proc_nommu_init);
 145