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 static void pad_len_spaces(struct seq_file *m, int len)
 126 {
 127         len = 25 + sizeof(void*) * 6 - len;
 128         if (len < 1)
 129                 len = 1;
 130         seq_printf(m, "%*c", len, ' ');
 131 }
 132
 133 /*
 134  * display a single VMA to a sequenced file
 135  */
 136 static int nommu_vma_show(struct seq_file *m, struct vm_area_struct *vma)
 137 {
 138         struct mm_struct *mm = vma->vm_mm;
 139         unsigned long ino = 0;
 140         struct file *file;
 141         dev_t dev = 0;
 142         int flags, len;
 143         unsigned long long pgoff = 0;
 144
 145         flags = vma->vm_flags;
 146         file = vma->vm_file;
 147
 148         if (file) {
 149                 struct inode *inode = vma->vm_file->f_path.dentry->d_inode;
 150                 dev = inode->i_sb->s_dev;
 151                 ino = inode->i_ino;
 152                 pgoff = (loff_t)vma->vm_pgoff << PAGE_SHIFT;
 153         }
 154
 155         seq_printf(m,
 156                    "%08lx-%08lx %c%c%c%c %08llx %02x:%02x %lu %n",
 157                    vma->vm_start,
 158                    vma->vm_end,
 159                    flags & VM_READ ? 'r' : '-',
 160                    flags & VM_WRITE ? 'w' : '-',
 161                    flags & VM_EXEC ? 'x' : '-',
 162                    flags & VM_MAYSHARE ? flags & VM_SHARED ? 'S' : 's' : 'p',
 163                    pgoff,
 164                    MAJOR(dev), MINOR(dev), ino, &len);
 165
 166         if (file) {
 167                 pad_len_spaces(m, len);
 168                 seq_path(m, &file->f_path, "");
 169         } else if (mm) {
 170                 if (vma->vm_start <= mm->start_stack &&
 171                         vma->vm_end >= mm->start_stack) {
 172                         pad_len_spaces(m, len);
 173                         seq_puts(m, "[stack]");
 174                 }
 175         }
 176
 177         seq_putc(m, '\n');
 178         return 0;
 179 }
 180
 181 /*
 182  * display mapping lines for a particular process's /proc/pid/maps
 183  */
 184 static int show_map(struct seq_file *m, void *_p)
 185 {
 186         struct rb_node *p = _p;
 187
 188         return nommu_vma_show(m, rb_entry(p, struct vm_area_struct, vm_rb));
 189 }
 190
 191 static void *m_start(struct seq_file *m, loff_t *pos)
 192 {
 193         struct proc_maps_private *priv = m->private;
 194         struct mm_struct *mm;
 195         struct rb_node *p;
 196         loff_t n = *pos;
 197
 198         /* pin the task and mm whilst we play with them */
 199         priv->task = get_pid_task(priv->pid, PIDTYPE_PID);
 200         if (!priv->task)
 201                 return NULL;
 202
 203         mm = mm_for_maps(priv->task);
 204         if (!mm) {
 205                 put_task_struct(priv->task);
 206                 priv->task = NULL;
 207                 return NULL;
 208         }
 209         down_read(&mm->mmap_sem);
 210
 211         /* start from the Nth VMA */
 212         for (p = rb_first(&mm->mm_rb); p; p = rb_next(p))
 213                 if (n-- == 0)
 214                         return p;
 215         return NULL;
 216 }
 217
 218 static void m_stop(struct seq_file *m, void *_vml)
 219 {
 220         struct proc_maps_private *priv = m->private;
 221
 222         if (priv->task) {
 223                 struct mm_struct *mm = priv->task->mm;
 224                 up_read(&mm->mmap_sem);
 225                 mmput(mm);
 226                 put_task_struct(priv->task);
 227         }
 228 }
 229
 230 static void *m_next(struct seq_file *m, void *_p, loff_t *pos)
 231 {
 232         struct rb_node *p = _p;
 233
 234         (*pos)++;
 235         return p ? rb_next(p) : NULL;
 236 }
 237
 238 static const struct seq_operations proc_pid_maps_ops = {
 239         .start  = m_start,
 240         .next   = m_next,
 241         .stop   = m_stop,
 242         .show   = show_map
 243 };
 244
 245 static int maps_open(struct inode *inode, struct file *file)
 246 {
 247         struct proc_maps_private *priv;
 248         int ret = -ENOMEM;
 249
 250         priv = kzalloc(sizeof(*priv), GFP_KERNEL);
 251         if (priv) {
 252                 priv->pid = proc_pid(inode);
 253                 ret = seq_open(file, &proc_pid_maps_ops);
 254                 if (!ret) {
 255                         struct seq_file *m = file->private_data;
 256                         m->private = priv;
 257                 } else {
 258                         kfree(priv);
 259                 }
 260         }
 261         return ret;
 262 }
 263
 264 const struct file_operations proc_maps_operations = {
 265         .open           = maps_open,
 266         .read           = seq_read,
 267         .llseek         = seq_lseek,
 268         .release        = seq_release_private,
 269 };
 270