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