fs/proc/task_nommu.c

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