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/smp.h>
  25 #include <linux/seq_file.h>
  26 #include <linux/hugetlb.h>
  27 #include <linux/vmalloc.h>
  28 #include <asm/uaccess.h>
  29 #include <asm/pgtable.h>
  30 #include <asm/tlb.h>
  31 #include <asm/div64.h>
  32 #include "internal.h"
  33
  34 /*
  35  * display a single region to a sequenced file
  36  */
  37 static int nommu_region_show(struct seq_file *m, struct vm_region *region)
  38 {
  39         unsigned long ino = 0;
  40         struct file *file;
  41         dev_t dev = 0;
  42         int flags, len;
  43
  44         flags = region->vm_flags;
  45         file = region->vm_file;
  46
  47         if (file) {
  48                 struct inode *inode = file_inode(region->vm_file);
  49                 dev = inode->i_sb->s_dev;
  50                 ino = inode->i_ino;
  51         }
  52
  53         seq_printf(m,
  54                    "%08lx-%08lx %c%c%c%c %08llx %02x:%02x %lu %n",
  55                    region->vm_start,
  56                    region->vm_end,
  57                    flags & VM_READ ? 'r' : '-',
  58                    flags & VM_WRITE ? 'w' : '-',
  59                    flags & VM_EXEC ? 'x' : '-',
  60                    flags & VM_MAYSHARE ? flags & VM_SHARED ? 'S' : 's' : 'p',
  61                    ((loff_t)region->vm_pgoff) << PAGE_SHIFT,
  62                    MAJOR(dev), MINOR(dev), ino, &len);
  63
  64         if (file) {
  65                 len = 25 + sizeof(void *) * 6 - len;
  66                 if (len < 1)
  67                         len = 1;
  68                 seq_printf(m, "%*c", len, ' ');
  69                 seq_path(m, &file->f_path, "");
  70         }
  71
  72         seq_putc(m, '\n');
  73         return 0;
  74 }
  75
  76 /*
  77  * display a list of all the REGIONs the kernel knows about
  78  * - nommu kernels have a single flat list
  79  */
  80 static int nommu_region_list_show(struct seq_file *m, void *_p)
  81 {
  82         struct rb_node *p = _p;
  83
  84         return nommu_region_show(m, rb_entry(p, struct vm_region, vm_rb));
  85 }
  86
  87 static void *nommu_region_list_start(struct seq_file *m, loff_t *_pos)
  88 {
  89         struct rb_node *p;
  90         loff_t pos = *_pos;
  91
  92         down_read(&nommu_region_sem);
  93
  94         for (p = rb_first(&nommu_region_tree); p; p = rb_next(p))
  95                 if (pos-- == 0)
  96                         return p;
  97         return NULL;
  98 }
  99
 100 static void nommu_region_list_stop(struct seq_file *m, void *v)
 101 {
 102         up_read(&nommu_region_sem);
 103 }
 104
 105 static void *nommu_region_list_next(struct seq_file *m, void *v, loff_t *pos)
 106 {
 107         (*pos)++;
 108         return rb_next((struct rb_node *) v);
 109 }
 110
 111 static const struct seq_operations proc_nommu_region_list_seqop = {
 112         .start  = nommu_region_list_start,
 113         .next   = nommu_region_list_next,
 114         .stop   = nommu_region_list_stop,
 115         .show   = nommu_region_list_show
 116 };
 117
 118 static int proc_nommu_region_list_open(struct inode *inode, struct file *file)
 119 {
 120         return seq_open(file, &proc_nommu_region_list_seqop);
 121 }
 122
 123 static const struct file_operations proc_nommu_region_list_operations = {
 124         .open    = proc_nommu_region_list_open,
 125         .read    = seq_read,
 126         .llseek  = seq_lseek,
 127         .release = seq_release,
 128 };
 129
 130 static int __init proc_nommu_init(void)
 131 {
 132         proc_create("maps", S_IRUGO, NULL, &proc_nommu_region_list_operations);
 133         return 0;
 134 }
 135
 136 module_init(proc_nommu_init);