fs/proc/task_nommu.c

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