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 region to a sequenced file
  37  */
  38 static int nommu_region_show(struct seq_file *m, struct vm_region *region)
  39 {
  40         unsigned long ino = 0;
  41         struct file *file;
  42         dev_t dev = 0;
  43         int flags, len;
  44
  45         flags = region->vm_flags;
  46         file = region->vm_file;
  47
  48         if (file) {
  49                 struct inode *inode = region->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                    region->vm_start,
  57                    region->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)region->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 REGIONs the kernel knows about
  79  * - nommu kernels have a single flat list
  80  */
  81 static int nommu_region_list_show(struct seq_file *m, void *_p)
  82 {
  83         struct rb_node *p = _p;
  84
  85         return nommu_region_show(m, rb_entry(p, struct vm_region, vm_rb));
  86 }
  87
  88 static void *nommu_region_list_start(struct seq_file *m, loff_t *_pos)
  89 {
  90         struct rb_node *p;
  91         loff_t pos = *_pos;
  92
  93         down_read(&nommu_region_sem);
  94
  95         for (p = rb_first(&nommu_region_tree); p; p = rb_next(p))
  96                 if (pos-- == 0)
  97                         return p;
  98         return NULL;
  99 }
 100
 101 static void nommu_region_list_stop(struct seq_file *m, void *v)
 102 {
 103         up_read(&nommu_region_sem);
 104 }
 105
 106 static void *nommu_region_list_next(struct seq_file *m, void *v, loff_t *pos)
 107 {
 108         (*pos)++;
 109         return rb_next((struct rb_node *) v);
 110 }
 111
 112 static const struct seq_operations proc_nommu_region_list_seqop = {
 113         .start  = nommu_region_list_start,
 114         .next   = nommu_region_list_next,
 115         .stop   = nommu_region_list_stop,
 116         .show   = nommu_region_list_show
 117 };
 118
 119 static int proc_nommu_region_list_open(struct inode *inode, struct file *file)
 120 {
 121         return seq_open(file, &proc_nommu_region_list_seqop);
 122 }
 123
 124 static const struct file_operations proc_nommu_region_list_operations = {
 125         .open    = proc_nommu_region_list_open,
 126         .read    = seq_read,
 127         .llseek  = seq_lseek,
 128         .release = seq_release,
 129 };
 130
 131 static int __init proc_nommu_init(void)
 132 {
 133         proc_create("maps", S_IRUGO, NULL, &proc_nommu_region_list_operations);
 134         return 0;
 135 }
 136
 137 module_init(proc_nommu_init);