fs/proc/task_nommu.c

   1
   2 #include <linux/mm.h>
   3 #include <linux/file.h>
   4 #include <linux/fdtable.h>
   5 #include <linux/fs_struct.h>
   6 #include <linux/mount.h>
   7 #include <linux/ptrace.h>
   8 #include <linux/seq_file.h>
   9 #include "internal.h"
  10
  11 /*
  12  * Logic: we've got two memory sums for each process, "shared", and
  13  * "non-shared". Shared memory may get counted more than once, for
  14  * each process that owns it. Non-shared memory is counted
  15  * accurately.
  16  */
  17 void task_mem(struct seq_file *m, struct mm_struct *mm)
  18 {
  19         struct vm_area_struct *vma;
  20         struct vm_region *region;
  21         struct rb_node *p;
  22         unsigned long bytes = 0, sbytes = 0, slack = 0, size;
  23
  24         down_read(&mm->mmap_sem);
  25         for (p = rb_first(&mm->mm_rb); p; p = rb_next(p)) {
  26                 vma = rb_entry(p, struct vm_area_struct, vm_rb);
  27
  28                 bytes += kobjsize(vma);
  29
  30                 region = vma->vm_region;
  31                 if (region) {
  32                         size = kobjsize(region);
  33                         size += region->vm_end - region->vm_start;
  34                 } else {
  35                         size = vma->vm_end - vma->vm_start;
  36                 }
  37
  38                 if (atomic_read(&mm->mm_count) > 1 ||
  39                     vma->vm_flags & VM_MAYSHARE) {
  40                         sbytes += size;
  41                 } else {
  42                         bytes += size;
  43                         if (region)
  44                                 slack = region->vm_end - vma->vm_end;
  45                 }
  46         }
  47
  48         if (atomic_read(&mm->mm_count) > 1)
  49                 sbytes += kobjsize(mm);
  50         else
  51                 bytes += kobjsize(mm);
  52
  53         if (current->fs && current->fs->users > 1)
  54                 sbytes += kobjsize(current->fs);
  55         else
  56                 bytes += kobjsize(current->fs);
  57
  58         if (current->files && atomic_read(&current->files->count) > 1)
  59                 sbytes += kobjsize(current->files);
  60         else
  61                 bytes += kobjsize(current->files);
  62
  63         if (current->sighand && atomic_read(&current->sighand->count) > 1)
  64                 sbytes += kobjsize(current->sighand);
  65         else
  66                 bytes += kobjsize(current->sighand);
  67
  68         bytes += kobjsize(current); /* includes kernel stack */
  69
  70         seq_printf(m,
  71                 "Mem:\t%8lu bytes\n"
  72                 "Slack:\t%8lu bytes\n"
  73                 "Shared:\t%8lu bytes\n",
  74                 bytes, slack, sbytes);
  75
  76         up_read(&mm->mmap_sem);
  77 }
  78
  79 unsigned long task_vsize(struct mm_struct *mm)
  80 {
  81         struct vm_area_struct *vma;
  82         struct rb_node *p;
  83         unsigned long vsize = 0;
  84
  85         down_read(&mm->mmap_sem);
  86         for (p = rb_first(&mm->mm_rb); p; p = rb_next(p)) {
  87                 vma = rb_entry(p, struct vm_area_struct, vm_rb);
  88                 vsize += vma->vm_end - vma->vm_start;
  89         }
  90         up_read(&mm->mmap_sem);
  91         return vsize;
  92 }
  93
  94 int task_statm(struct mm_struct *mm, int *shared, int *text,
  95                int *data, int *resident)
  96 {
  97         struct vm_area_struct *vma;
  98         struct vm_region *region;
  99         struct rb_node *p;
 100         int size = kobjsize(mm);
 101
 102         down_read(&mm->mmap_sem);
 103         for (p = rb_first(&mm->mm_rb); p; p = rb_next(p)) {
 104                 vma = rb_entry(p, struct vm_area_struct, vm_rb);
 105                 size += kobjsize(vma);
 106                 region = vma->vm_region;
 107                 if (region) {
 108                         size += kobjsize(region);
 109                         size += region->vm_end - region->vm_start;
 110                 }
 111         }
 112
 113         size += (*text = mm->end_code - mm->start_code);
 114         size += (*data = mm->start_stack - mm->start_data);
 115         up_read(&mm->mmap_sem);
 116         *resident = size;
 117         return size;
 118 }
 119
 120 /*
 121  * display a single VMA to a sequenced file
 122  */
 123 static int nommu_vma_show(struct seq_file *m, struct vm_area_struct *vma)
 124 {
 125         unsigned long ino = 0;
 126         struct file *file;
 127         dev_t dev = 0;
 128         int flags, len;
 129         unsigned long long pgoff = 0;
 130
 131         flags = vma->vm_flags;
 132         file = vma->vm_file;
 133
 134         if (file) {
 135                 struct inode *inode = vma->vm_file->f_path.dentry->d_inode;
 136                 dev = inode->i_sb->s_dev;
 137                 ino = inode->i_ino;
 138                 pgoff = (loff_t)vma->vm_pgoff << PAGE_SHIFT;
 139         }
 140
 141         seq_printf(m,
 142                    "%08lx-%08lx %c%c%c%c %08llx %02x:%02x %lu %n",
 143                    vma->vm_start,
 144                    vma->vm_end,
 145                    flags & VM_READ ? 'r' : '-',
 146                    flags & VM_WRITE ? 'w' : '-',
 147                    flags & VM_EXEC ? 'x' : '-',
 148                    flags & VM_MAYSHARE ? flags & VM_SHARED ? 'S' : 's' : 'p',
 149                    pgoff,
 150                    MAJOR(dev), MINOR(dev), ino, &len);
 151
 152         if (file) {
 153                 len = 25 + sizeof(void *) * 6 - len;
 154                 if (len < 1)
 155                         len = 1;
 156                 seq_printf(m, "%*c", len, ' ');
 157                 seq_path(m, &file->f_path, "");
 158         }
 159
 160         seq_putc(m, '\n');
 161         return 0;
 162 }
 163
 164 /*
 165  * display mapping lines for a particular process's /proc/pid/maps
 166  */
 167 static int show_map(struct seq_file *m, void *_p)
 168 {
 169         struct rb_node *p = _p;
 170
 171         return nommu_vma_show(m, rb_entry(p, struct vm_area_struct, vm_rb));
 172 }
 173
 174 static void *m_start(struct seq_file *m, loff_t *pos)
 175 {
 176         struct proc_maps_private *priv = m->private;
 177         struct mm_struct *mm;
 178         struct rb_node *p;
 179         loff_t n = *pos;
 180
 181         /* pin the task and mm whilst we play with them */
 182         priv->task = get_pid_task(priv->pid, PIDTYPE_PID);
 183         if (!priv->task)
 184                 return NULL;
 185
 186         mm = mm_for_maps(priv->task);
 187         if (!mm) {
 188                 put_task_struct(priv->task);
 189                 priv->task = NULL;
 190                 return NULL;
 191         }
 192
 193         /* start from the Nth VMA */
 194         for (p = rb_first(&mm->mm_rb); p; p = rb_next(p))
 195                 if (n-- == 0)
 196                         return p;
 197         return NULL;
 198 }
 199
 200 static void m_stop(struct seq_file *m, void *_vml)
 201 {
 202         struct proc_maps_private *priv = m->private;
 203
 204         if (priv->task) {
 205                 struct mm_struct *mm = priv->task->mm;
 206                 up_read(&mm->mmap_sem);
 207                 mmput(mm);
 208                 put_task_struct(priv->task);
 209         }
 210 }
 211
 212 static void *m_next(struct seq_file *m, void *_p, loff_t *pos)
 213 {
 214         struct rb_node *p = _p;
 215
 216         (*pos)++;
 217         return p ? rb_next(p) : NULL;
 218 }
 219
 220 static const struct seq_operations proc_pid_maps_ops = {
 221         .start  = m_start,
 222         .next   = m_next,
 223         .stop   = m_stop,
 224         .show   = show_map
 225 };
 226
 227 static int maps_open(struct inode *inode, struct file *file)
 228 {
 229         struct proc_maps_private *priv;
 230         int ret = -ENOMEM;
 231
 232         priv = kzalloc(sizeof(*priv), GFP_KERNEL);
 233         if (priv) {
 234                 priv->pid = proc_pid(inode);
 235                 ret = seq_open(file, &proc_pid_maps_ops);
 236                 if (!ret) {
 237                         struct seq_file *m = file->private_data;
 238                         m->private = priv;
 239                 } else {
 240                         kfree(priv);
 241                 }
 242         }
 243         return ret;
 244 }
 245
 246 const struct file_operations proc_maps_operations = {
 247         .open           = maps_open,
 248         .read           = seq_read,
 249         .llseek         = seq_lseek,
 250         .release        = seq_release_private,
 251 };
 252