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