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 void task_mem(struct seq_file *m, struct mm_struct *mm)
  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         seq_printf(m,
  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 }
  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         struct proc_maps_private *priv = m->private;
 147         struct task_struct *task = priv->task;
 148
 149         if (maps_protect && !ptrace_may_attach(task))
 150                 return -EACCES;
 151
 152         return nommu_vma_show(m, vml->vma);
 153 }
 154
 155 static void *m_start(struct seq_file *m, loff_t *pos)
 156 {
 157         struct proc_maps_private *priv = m->private;
 158         struct vm_list_struct *vml;
 159         struct mm_struct *mm;
 160         loff_t n = *pos;
 161
 162         /* pin the task and mm whilst we play with them */
 163         priv->task = get_pid_task(priv->pid, PIDTYPE_PID);
 164         if (!priv->task)
 165                 return NULL;
 166
 167         mm = mm_for_maps(priv->task);
 168         if (!mm) {
 169                 put_task_struct(priv->task);
 170                 priv->task = NULL;
 171                 return NULL;
 172         }
 173
 174         /* start from the Nth VMA */
 175         for (vml = mm->context.vmlist; vml; vml = vml->next)
 176                 if (n-- == 0)
 177                         return vml;
 178         return NULL;
 179 }
 180
 181 static void m_stop(struct seq_file *m, void *_vml)
 182 {
 183         struct proc_maps_private *priv = m->private;
 184
 185         if (priv->task) {
 186                 struct mm_struct *mm = priv->task->mm;
 187                 up_read(&mm->mmap_sem);
 188                 mmput(mm);
 189                 put_task_struct(priv->task);
 190         }
 191 }
 192
 193 static void *m_next(struct seq_file *m, void *_vml, loff_t *pos)
 194 {
 195         struct vm_list_struct *vml = _vml;
 196
 197         (*pos)++;
 198         return vml ? vml->next : NULL;
 199 }
 200
 201 static const struct seq_operations proc_pid_maps_ops = {
 202         .start  = m_start,
 203         .next   = m_next,
 204         .stop   = m_stop,
 205         .show   = show_map
 206 };
 207
 208 static int maps_open(struct inode *inode, struct file *file)
 209 {
 210         struct proc_maps_private *priv;
 211         int ret = -ENOMEM;
 212
 213         priv = kzalloc(sizeof(*priv), GFP_KERNEL);
 214         if (priv) {
 215                 priv->pid = proc_pid(inode);
 216                 ret = seq_open(file, &proc_pid_maps_ops);
 217                 if (!ret) {
 218                         struct seq_file *m = file->private_data;
 219                         m->private = priv;
 220                 } else {
 221                         kfree(priv);
 222                 }
 223         }
 224         return ret;
 225 }
 226
 227 const struct file_operations proc_maps_operations = {
 228         .open           = maps_open,
 229         .read           = seq_read,
 230         .llseek         = seq_lseek,
 231         .release        = seq_release_private,
 232 };
 233