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 {
 139         struct mm_struct *mm = vma->vm_mm;
 140         unsigned long ino = 0;
 141         struct file *file;
 142         dev_t dev = 0;
 143         int flags, len;
 144         unsigned long long pgoff = 0;
 145
 146         flags = vma->vm_flags;
 147         file = vma->vm_file;
 148
 149         if (file) {
 150                 struct inode *inode = vma->vm_file->f_path.dentry->d_inode;
 151                 dev = inode->i_sb->s_dev;
 152                 ino = inode->i_ino;
 153                 pgoff = (loff_t)vma->vm_pgoff << PAGE_SHIFT;
 154         }
 155
 156         seq_printf(m,
 157                    "%08lx-%08lx %c%c%c%c %08llx %02x:%02x %lu %n",
 158                    vma->vm_start,
 159                    vma->vm_end,
 160                    flags & VM_READ ? 'r' : '-',
 161                    flags & VM_WRITE ? 'w' : '-',
 162                    flags & VM_EXEC ? 'x' : '-',
 163                    flags & VM_MAYSHARE ? flags & VM_SHARED ? 'S' : 's' : 'p',
 164                    pgoff,
 165                    MAJOR(dev), MINOR(dev), ino, &len);
 166
 167         if (file) {
 168                 pad_len_spaces(m, len);
 169                 seq_path(m, &file->f_path, "");
 170         } else if (mm) {
 171                 if (vma->vm_start <= mm->start_stack &&
 172                         vma->vm_end >= mm->start_stack) {
 173                         pad_len_spaces(m, len);
 174                         seq_puts(m, "[stack]");
 175                 }
 176         }
 177
 178         seq_putc(m, '\n');
 179         return 0;
 180 }
 181
 182 /*
 183  * display mapping lines for a particular process's /proc/pid/maps
 184  */
 185 static int show_map(struct seq_file *m, void *_p)
 186 {
 187         struct rb_node *p = _p;
 188
 189         return nommu_vma_show(m, rb_entry(p, struct vm_area_struct, vm_rb));
 190 }
 191
 192 static void *m_start(struct seq_file *m, loff_t *pos)
 193 {
 194         struct proc_maps_private *priv = m->private;
 195         struct mm_struct *mm;
 196         struct rb_node *p;
 197         loff_t n = *pos;
 198
 199         /* pin the task and mm whilst we play with them */
 200         priv->task = get_pid_task(priv->pid, PIDTYPE_PID);
 201         if (!priv->task)
 202                 return ERR_PTR(-ESRCH);
 203
 204         mm = mm_for_maps(priv->task);
 205         if (!mm || IS_ERR(mm)) {
 206                 put_task_struct(priv->task);
 207                 priv->task = NULL;
 208                 return mm;
 209         }
 210         down_read(&mm->mmap_sem);
 211
 212         /* start from the Nth VMA */
 213         for (p = rb_first(&mm->mm_rb); p; p = rb_next(p))
 214                 if (n-- == 0)
 215                         return p;
 216         return NULL;
 217 }
 218
 219 static void m_stop(struct seq_file *m, void *_vml)
 220 {
 221         struct proc_maps_private *priv = m->private;
 222
 223         if (priv->task) {
 224                 struct mm_struct *mm = priv->task->mm;
 225                 up_read(&mm->mmap_sem);
 226                 mmput(mm);
 227                 put_task_struct(priv->task);
 228         }
 229 }
 230
 231 static void *m_next(struct seq_file *m, void *_p, loff_t *pos)
 232 {
 233         struct rb_node *p = _p;
 234
 235         (*pos)++;
 236         return p ? rb_next(p) : NULL;
 237 }
 238
 239 static const struct seq_operations proc_pid_maps_ops = {
 240         .start  = m_start,
 241         .next   = m_next,
 242         .stop   = m_stop,
 243         .show   = show_map
 244 };
 245
 246 static int maps_open(struct inode *inode, struct file *file)
 247 {
 248         struct proc_maps_private *priv;
 249         int ret = -ENOMEM;
 250
 251         priv = kzalloc(sizeof(*priv), GFP_KERNEL);
 252         if (priv) {
 253                 priv->pid = proc_pid(inode);
 254                 ret = seq_open(file, &proc_pid_maps_ops);
 255                 if (!ret) {
 256                         struct seq_file *m = file->private_data;
 257                         m->private = priv;
 258                 } else {
 259                         kfree(priv);
 260                 }
 261         }
 262         return ret;
 263 }
 264
 265 const struct file_operations proc_maps_operations = {
 266         .open           = maps_open,
 267         .read           = seq_read,
 268         .llseek         = seq_lseek,
 269         .release        = seq_release_private,
 270 };
 271