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/slab.h>
   9 #include <linux/seq_file.h>
  10 #include "internal.h"
  11
  12 /*
  13  * Logic: we've got two memory sums for each process, "shared", and
  14  * "non-shared". Shared memory may get counted more than once, for
  15  * each process that owns it. Non-shared memory is counted
  16  * accurately.
  17  */
  18 void task_mem(struct seq_file *m, struct mm_struct *mm)
  19 {
  20         struct vm_area_struct *vma;
  21         struct vm_region *region;
  22         struct rb_node *p;
  23         unsigned long bytes = 0, sbytes = 0, slack = 0, size;
  24
  25         down_read(&mm->mmap_sem);
  26         for (p = rb_first(&mm->mm_rb); p; p = rb_next(p)) {
  27                 vma = rb_entry(p, struct vm_area_struct, vm_rb);
  28
  29                 bytes += kobjsize(vma);
  30
  31                 region = vma->vm_region;
  32                 if (region) {
  33                         size = kobjsize(region);
  34                         size += region->vm_end - region->vm_start;
  35                 } else {
  36                         size = vma->vm_end - vma->vm_start;
  37                 }
  38
  39                 if (atomic_read(&mm->mm_count) > 1 ||
  40                     vma->vm_flags & VM_MAYSHARE) {
  41                         sbytes += size;
  42                 } else {
  43                         bytes += size;
  44                         if (region)
  45                                 slack = region->vm_end - vma->vm_end;
  46                 }
  47         }
  48
  49         if (atomic_read(&mm->mm_count) > 1)
  50                 sbytes += kobjsize(mm);
  51         else
  52                 bytes += kobjsize(mm);
  53
  54         if (current->fs && current->fs->users > 1)
  55                 sbytes += kobjsize(current->fs);
  56         else
  57                 bytes += kobjsize(current->fs);
  58
  59         if (current->files && atomic_read(&current->files->count) > 1)
  60                 sbytes += kobjsize(current->files);
  61         else
  62                 bytes += kobjsize(current->files);
  63
  64         if (current->sighand && atomic_read(&current->sighand->count) > 1)
  65                 sbytes += kobjsize(current->sighand);
  66         else
  67                 bytes += kobjsize(current->sighand);
  68
  69         bytes += kobjsize(current); /* includes kernel stack */
  70
  71         seq_printf(m,
  72                 "Mem:\t%8lu bytes\n"
  73                 "Slack:\t%8lu bytes\n"
  74                 "Shared:\t%8lu bytes\n",
  75                 bytes, slack, sbytes);
  76
  77         up_read(&mm->mmap_sem);
  78 }
  79
  80 unsigned long task_vsize(struct mm_struct *mm)
  81 {
  82         struct vm_area_struct *vma;
  83         struct rb_node *p;
  84         unsigned long vsize = 0;
  85
  86         down_read(&mm->mmap_sem);
  87         for (p = rb_first(&mm->mm_rb); p; p = rb_next(p)) {
  88                 vma = rb_entry(p, struct vm_area_struct, vm_rb);
  89                 vsize += vma->vm_end - vma->vm_start;
  90         }
  91         up_read(&mm->mmap_sem);
  92         return vsize;
  93 }
  94
  95 int task_statm(struct mm_struct *mm, int *shared, int *text,
  96                int *data, int *resident)
  97 {
  98         struct vm_area_struct *vma;
  99         struct vm_region *region;
 100         struct rb_node *p;
 101         int size = kobjsize(mm);
 102
 103         down_read(&mm->mmap_sem);
 104         for (p = rb_first(&mm->mm_rb); p; p = rb_next(p)) {
 105                 vma = rb_entry(p, struct vm_area_struct, vm_rb);
 106                 size += kobjsize(vma);
 107                 region = vma->vm_region;
 108                 if (region) {
 109                         size += kobjsize(region);
 110                         size += region->vm_end - region->vm_start;
 111                 }
 112         }
 113
 114         *text = (PAGE_ALIGN(mm->end_code) - (mm->start_code & PAGE_MASK))
 115                 >> PAGE_SHIFT;
 116         *data = (PAGE_ALIGN(mm->start_stack) - (mm->start_data & PAGE_MASK))
 117                 >> PAGE_SHIFT;
 118         up_read(&mm->mmap_sem);
 119         size >>= PAGE_SHIFT;
 120         size += *text + *data;
 121         *resident = size;
 122         return size;
 123 }
 124
 125 /*
 126  * display a single VMA to a sequenced file
 127  */
 128 static int nommu_vma_show(struct seq_file *m, struct vm_area_struct *vma)
 129 {
 130         unsigned long ino = 0;
 131         struct file *file;
 132         dev_t dev = 0;
 133         int flags, len;
 134         unsigned long long pgoff = 0;
 135
 136         flags = vma->vm_flags;
 137         file = vma->vm_file;
 138
 139         if (file) {
 140                 struct inode *inode = vma->vm_file->f_path.dentry->d_inode;
 141                 dev = inode->i_sb->s_dev;
 142                 ino = inode->i_ino;
 143                 pgoff = (loff_t)vma->vm_pgoff << PAGE_SHIFT;
 144         }
 145
 146         seq_printf(m,
 147                    "%08lx-%08lx %c%c%c%c %08llx %02x:%02x %lu %n",
 148                    vma->vm_start,
 149                    vma->vm_end,
 150                    flags & VM_READ ? 'r' : '-',
 151                    flags & VM_WRITE ? 'w' : '-',
 152                    flags & VM_EXEC ? 'x' : '-',
 153                    flags & VM_MAYSHARE ? flags & VM_SHARED ? 'S' : 's' : 'p',
 154                    pgoff,
 155                    MAJOR(dev), MINOR(dev), ino, &len);
 156
 157         if (file) {
 158                 len = 25 + sizeof(void *) * 6 - len;
 159                 if (len < 1)
 160                         len = 1;
 161                 seq_printf(m, "%*c", len, ' ');
 162                 seq_path(m, &file->f_path, "");
 163         }
 164
 165         seq_putc(m, '\n');
 166         return 0;
 167 }
 168
 169 /*
 170  * display mapping lines for a particular process's /proc/pid/maps
 171  */
 172 static int show_map(struct seq_file *m, void *_p)
 173 {
 174         struct rb_node *p = _p;
 175
 176         return nommu_vma_show(m, rb_entry(p, struct vm_area_struct, vm_rb));
 177 }
 178
 179 static void *m_start(struct seq_file *m, loff_t *pos)
 180 {
 181         struct proc_maps_private *priv = m->private;
 182         struct mm_struct *mm;
 183         struct rb_node *p;
 184         loff_t n = *pos;
 185
 186         /* pin the task and mm whilst we play with them */
 187         priv->task = get_pid_task(priv->pid, PIDTYPE_PID);
 188         if (!priv->task)
 189                 return NULL;
 190
 191         mm = mm_for_maps(priv->task);
 192         if (!mm) {
 193                 put_task_struct(priv->task);
 194                 priv->task = NULL;
 195                 return NULL;
 196         }
 197         down_read(&mm->mmap_sem);
 198
 199         /* start from the Nth VMA */
 200         for (p = rb_first(&mm->mm_rb); p; p = rb_next(p))
 201                 if (n-- == 0)
 202                         return p;
 203         return NULL;
 204 }
 205
 206 static void m_stop(struct seq_file *m, void *_vml)
 207 {
 208         struct proc_maps_private *priv = m->private;
 209
 210         if (priv->task) {
 211                 struct mm_struct *mm = priv->task->mm;
 212                 up_read(&mm->mmap_sem);
 213                 mmput(mm);
 214                 put_task_struct(priv->task);
 215         }
 216 }
 217
 218 static void *m_next(struct seq_file *m, void *_p, loff_t *pos)
 219 {
 220         struct rb_node *p = _p;
 221
 222         (*pos)++;
 223         return p ? rb_next(p) : NULL;
 224 }
 225
 226 static const struct seq_operations proc_pid_maps_ops = {
 227         .start  = m_start,
 228         .next   = m_next,
 229         .stop   = m_stop,
 230         .show   = show_map
 231 };
 232
 233 static int maps_open(struct inode *inode, struct file *file)
 234 {
 235         struct proc_maps_private *priv;
 236         int ret = -ENOMEM;
 237
 238         priv = kzalloc(sizeof(*priv), GFP_KERNEL);
 239         if (priv) {
 240                 priv->pid = proc_pid(inode);
 241                 ret = seq_open(file, &proc_pid_maps_ops);
 242                 if (!ret) {
 243                         struct seq_file *m = file->private_data;
 244                         m->private = priv;
 245                 } else {
 246                         kfree(priv);
 247                 }
 248         }
 249         return ret;
 250 }
 251
 252 const struct file_operations proc_maps_operations = {
 253         .open           = maps_open,
 254         .read           = seq_read,
 255         .llseek         = seq_lseek,
 256         .release        = seq_release_private,
 257 };
 258