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