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 unsigned long task_statm(struct mm_struct *mm,
  96                          unsigned long *shared, unsigned long *text,
  97                          unsigned long *data, unsigned long *resident)
  98 {
  99         struct vm_area_struct *vma;
 100         struct vm_region *region;
 101         struct rb_node *p;
 102         unsigned long size = kobjsize(mm);
 103
 104         down_read(&mm->mmap_sem);
 105         for (p = rb_first(&mm->mm_rb); p; p = rb_next(p)) {
 106                 vma = rb_entry(p, struct vm_area_struct, vm_rb);
 107                 size += kobjsize(vma);
 108                 region = vma->vm_region;
 109                 if (region) {
 110                         size += kobjsize(region);
 111                         size += region->vm_end - region->vm_start;
 112                 }
 113         }
 114
 115         *text = (PAGE_ALIGN(mm->end_code) - (mm->start_code & PAGE_MASK))
 116                 >> PAGE_SHIFT;
 117         *data = (PAGE_ALIGN(mm->start_stack) - (mm->start_data & PAGE_MASK))
 118                 >> PAGE_SHIFT;
 119         up_read(&mm->mmap_sem);
 120         size >>= PAGE_SHIFT;
 121         size += *text + *data;
 122         *resident = size;
 123         return size;
 124 }
 125
 126 static pid_t pid_of_stack(struct proc_maps_private *priv,
 127                                 struct vm_area_struct *vma, bool is_pid)
 128 {
 129         struct inode *inode = priv->inode;
 130         struct task_struct *task;
 131         pid_t ret = 0;
 132
 133         rcu_read_lock();
 134         task = pid_task(proc_pid(inode), PIDTYPE_PID);
 135         if (task) {
 136                 task = task_of_stack(task, vma, is_pid);
 137                 if (task)
 138                         ret = task_pid_nr_ns(task, inode->i_sb->s_fs_info);
 139         }
 140         rcu_read_unlock();
 141
 142         return ret;
 143 }
 144
 145 /*
 146  * display a single VMA to a sequenced file
 147  */
 148 static int nommu_vma_show(struct seq_file *m, struct vm_area_struct *vma,
 149                           int is_pid)
 150 {
 151         struct mm_struct *mm = vma->vm_mm;
 152         struct proc_maps_private *priv = m->private;
 153         unsigned long ino = 0;
 154         struct file *file;
 155         dev_t dev = 0;
 156         int flags;
 157         unsigned long long pgoff = 0;
 158
 159         flags = vma->vm_flags;
 160         file = vma->vm_file;
 161
 162         if (file) {
 163                 struct inode *inode = file_inode(vma->vm_file);
 164                 dev = inode->i_sb->s_dev;
 165                 ino = inode->i_ino;
 166                 pgoff = (loff_t)vma->vm_pgoff << PAGE_SHIFT;
 167         }
 168
 169         seq_setwidth(m, 25 + sizeof(void *) * 6 - 1);
 170         seq_printf(m,
 171                    "%08lx-%08lx %c%c%c%c %08llx %02x:%02x %lu ",
 172                    vma->vm_start,
 173                    vma->vm_end,
 174                    flags & VM_READ ? 'r' : '-',
 175                    flags & VM_WRITE ? 'w' : '-',
 176                    flags & VM_EXEC ? 'x' : '-',
 177                    flags & VM_MAYSHARE ? flags & VM_SHARED ? 'S' : 's' : 'p',
 178                    pgoff,
 179                    MAJOR(dev), MINOR(dev), ino);
 180
 181         if (file) {
 182                 seq_pad(m, ' ');
 183                 seq_file_path(m, file, "");
 184         } else if (mm) {
 185                 pid_t tid = pid_of_stack(priv, vma, is_pid);
 186
 187                 if (tid != 0) {
 188                         seq_pad(m, ' ');
 189                         /*
 190                          * Thread stack in /proc/PID/task/TID/maps or
 191                          * the main process stack.
 192                          */
 193                         if (!is_pid || (vma->vm_start <= mm->start_stack &&
 194                             vma->vm_end >= mm->start_stack))
 195                                 seq_printf(m, "[stack]");
 196                         else
 197                                 seq_printf(m, "[stack:%d]", tid);
 198                 }
 199         }
 200
 201         seq_putc(m, '\n');
 202         return 0;
 203 }
 204
 205 /*
 206  * display mapping lines for a particular process's /proc/pid/maps
 207  */
 208 static int show_map(struct seq_file *m, void *_p, int is_pid)
 209 {
 210         struct rb_node *p = _p;
 211
 212         return nommu_vma_show(m, rb_entry(p, struct vm_area_struct, vm_rb),
 213                               is_pid);
 214 }
 215
 216 static int show_pid_map(struct seq_file *m, void *_p)
 217 {
 218         return show_map(m, _p, 1);
 219 }
 220
 221 static int show_tid_map(struct seq_file *m, void *_p)
 222 {
 223         return show_map(m, _p, 0);
 224 }
 225
 226 static void *m_start(struct seq_file *m, loff_t *pos)
 227 {
 228         struct proc_maps_private *priv = m->private;
 229         struct mm_struct *mm;
 230         struct rb_node *p;
 231         loff_t n = *pos;
 232
 233         /* pin the task and mm whilst we play with them */
 234         priv->task = get_proc_task(priv->inode);
 235         if (!priv->task)
 236                 return ERR_PTR(-ESRCH);
 237
 238         mm = priv->mm;
 239         if (!mm || !atomic_inc_not_zero(&mm->mm_users))
 240                 return NULL;
 241
 242         down_read(&mm->mmap_sem);
 243         /* start from the Nth VMA */
 244         for (p = rb_first(&mm->mm_rb); p; p = rb_next(p))
 245                 if (n-- == 0)
 246                         return p;
 247
 248         up_read(&mm->mmap_sem);
 249         mmput(mm);
 250         return NULL;
 251 }
 252
 253 static void m_stop(struct seq_file *m, void *_vml)
 254 {
 255         struct proc_maps_private *priv = m->private;
 256
 257         if (!IS_ERR_OR_NULL(_vml)) {
 258                 up_read(&priv->mm->mmap_sem);
 259                 mmput(priv->mm);
 260         }
 261         if (priv->task) {
 262                 put_task_struct(priv->task);
 263                 priv->task = NULL;
 264         }
 265 }
 266
 267 static void *m_next(struct seq_file *m, void *_p, loff_t *pos)
 268 {
 269         struct rb_node *p = _p;
 270
 271         (*pos)++;
 272         return p ? rb_next(p) : NULL;
 273 }
 274
 275 static const struct seq_operations proc_pid_maps_ops = {
 276         .start  = m_start,
 277         .next   = m_next,
 278         .stop   = m_stop,
 279         .show   = show_pid_map
 280 };
 281
 282 static const struct seq_operations proc_tid_maps_ops = {
 283         .start  = m_start,
 284         .next   = m_next,
 285         .stop   = m_stop,
 286         .show   = show_tid_map
 287 };
 288
 289 static int maps_open(struct inode *inode, struct file *file,
 290                      const struct seq_operations *ops)
 291 {
 292         struct proc_maps_private *priv;
 293
 294         priv = __seq_open_private(file, ops, sizeof(*priv));
 295         if (!priv)
 296                 return -ENOMEM;
 297
 298         priv->inode = inode;
 299         priv->mm = proc_mem_open(inode, PTRACE_MODE_READ);
 300         if (IS_ERR(priv->mm)) {
 301                 int err = PTR_ERR(priv->mm);
 302
 303                 seq_release_private(inode, file);
 304                 return err;
 305         }
 306
 307         return 0;
 308 }
 309
 310
 311 static int map_release(struct inode *inode, struct file *file)
 312 {
 313         struct seq_file *seq = file->private_data;
 314         struct proc_maps_private *priv = seq->private;
 315
 316         if (priv->mm)
 317                 mmdrop(priv->mm);
 318
 319         return seq_release_private(inode, file);
 320 }
 321
 322 static int pid_maps_open(struct inode *inode, struct file *file)
 323 {
 324         return maps_open(inode, file, &proc_pid_maps_ops);
 325 }
 326
 327 static int tid_maps_open(struct inode *inode, struct file *file)
 328 {
 329         return maps_open(inode, file, &proc_tid_maps_ops);
 330 }
 331
 332 const struct file_operations proc_pid_maps_operations = {
 333         .open           = pid_maps_open,
 334         .read           = seq_read,
 335         .llseek         = seq_lseek,
 336         .release        = map_release,
 337 };
 338
 339 const struct file_operations proc_tid_maps_operations = {
 340         .open           = tid_maps_open,
 341         .read           = seq_read,
 342         .llseek         = seq_lseek,
 343         .release        = map_release,
 344 };
 345