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  */
  38 int 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 %08lx %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                    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.mnt, file->f_path.dentry, "");
  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  */
  81 static 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
  89 static 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
 108 static void nommu_vma_list_stop(struct seq_file *m, void *v)
 109 {
 110         up_read(&nommu_vma_sem);
 111 }
 112
 113 static 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
 119 static 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
 126 static 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
 131 static 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
 138 static int __init proc_nommu_init(void)
 139 {
 140         create_seq_entry("maps", S_IRUGO, &proc_nommu_vma_list_operations);
 141         return 0;
 142 }
 143
 144 module_init(proc_nommu_init);