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/seq_file.h>
   9 #include "internal.h"
  10
  11 /*
  12  * Logic: we've got two memory sums for each process, "shared", and
  13  * "non-shared". Shared memory may get counted more than once, for
  14  * each process that owns it. Non-shared memory is counted
  15  * accurately.
  16  */
  17 void task_mem(struct seq_file *m, struct mm_struct *mm)
  18 {
  19         struct vm_area_struct *vma;
  20         struct vm_region *region;
  21         struct rb_node *p;
  22         unsigned long bytes = 0, sbytes = 0, slack = 0, size;
  23
  24         down_read(&mm->mmap_sem);
  25         for (p = rb_first(&mm->mm_rb); p; p = rb_next(p)) {
  26                 vma = rb_entry(p, struct vm_area_struct, vm_rb);
  27
  28                 bytes += kobjsize(vma);
  29
  30                 region = vma->vm_region;
  31                 if (region) {
  32                         size = kobjsize(region);
  33                         size += region->vm_end - region->vm_start;
  34                 } else {
  35                         size = vma->vm_end - vma->vm_start;
  36                 }
  37
  38                 if (atomic_read(&mm->mm_count) > 1 ||
  39                     vma->vm_flags & VM_MAYSHARE) {
  40                         sbytes += size;
  41                 } else {
  42                         bytes += size;
  43                         if (region)
  44                                 slack = region->vm_end - vma->vm_end;
  45                 }
  46         }
  47
  48         if (atomic_read(&mm->mm_count) > 1)
  49                 sbytes += kobjsize(mm);
  50         else
  51                 bytes += kobjsize(mm);
  52
  53         if (current->fs && current->fs->users > 1)
  54                 sbytes += kobjsize(current->fs);
  55         else
  56                 bytes += kobjsize(current->fs);
  57
  58         if (current->files && atomic_read(&current->files->count) > 1)
  59                 sbytes += kobjsize(current->files);
  60         else
  61                 bytes += kobjsize(current->files);
  62
  63         if (current->sighand && atomic_read(&current->sighand->count) > 1)
  64                 sbytes += kobjsize(current->sighand);
  65         else
  66                 bytes += kobjsize(current->sighand);
  67
  68         bytes += kobjsize(current); /* includes kernel stack */
  69
  70         seq_printf(m,
  71                 "Mem:\t%8lu bytes\n"
  72                 "Slack:\t%8lu bytes\n"
  73                 "Shared:\t%8lu bytes\n",
  74                 bytes, slack, sbytes);
  75
  76         up_read(&mm->mmap_sem);
  77 }
  78
  79 unsigned long task_vsize(struct mm_struct *mm)
  80 {
  81         struct vm_area_struct *vma;
  82         struct rb_node *p;
  83         unsigned long vsize = 0;
  84
  85         down_read(&mm->mmap_sem);
  86         for (p = rb_first(&mm->mm_rb); p; p = rb_next(p)) {
  87                 vma = rb_entry(p, struct vm_area_struct, vm_rb);
  88                 vsize += vma->vm_end - vma->vm_start;
  89         }
  90         up_read(&mm->mmap_sem);
  91         return vsize;
  92 }
  93
  94 int task_statm(struct mm_struct *mm, int *shared, int *text,
  95                int *data, int *resident)
  96 {
  97         struct vm_area_struct *vma;
  98         struct vm_region *region;
  99         struct rb_node *p;
 100         int size = kobjsize(mm);
 101
 102         down_read(&mm->mmap_sem);
 103         for (p = rb_first(&mm->mm_rb); p; p = rb_next(p)) {
 104                 vma = rb_entry(p, struct vm_area_struct, vm_rb);
 105                 size += kobjsize(vma);
 106                 region = vma->vm_region;
 107                 if (region) {
 108                         size += kobjsize(region);
 109                         size += region->vm_end - region->vm_start;
 110                 }
 111         }
 112
 113         *text = (PAGE_ALIGN(mm->end_code) - (mm->start_code & PAGE_MASK))
 114                 >> PAGE_SHIFT;
 115         *data = (PAGE_ALIGN(mm->start_stack) - (mm->start_data & PAGE_MASK))
 116                 >> PAGE_SHIFT;
 117         up_read(&mm->mmap_sem);
 118         size >>= PAGE_SHIFT;
 119         size += *text + *data;
 120         *resident = size;
 121         return size;
 122 }
 123
 124 /*
 125  * display a single VMA to a sequenced file
 126  */
 127 static int nommu_vma_show(struct seq_file *m, struct vm_area_struct *vma)
 128 {
 129         unsigned long ino = 0;
 130         struct file *file;
 131         dev_t dev = 0;
 132         int flags, len;
 133         unsigned long long pgoff = 0;
 134
 135         flags = vma->vm_flags;
 136         file = vma->vm_file;
 137
 138         if (file) {
 139                 struct inode *inode = vma->vm_file->f_path.dentry->d_inode;
 140                 dev = inode->i_sb->s_dev;
 141                 ino = inode->i_ino;
 142                 pgoff = (loff_t)vma->vm_pgoff << PAGE_SHIFT;
 143         }
 144
 145         seq_printf(m,
 146                    "%08lx-%08lx %c%c%c%c %08llx %02x:%02x %lu %n",
 147                    vma->vm_start,
 148                    vma->vm_end,
 149                    flags & VM_READ ? 'r' : '-',
 150                    flags & VM_WRITE ? 'w' : '-',
 151                    flags & VM_EXEC ? 'x' : '-',
 152                    flags & VM_MAYSHARE ? flags & VM_SHARED ? 'S' : 's' : 'p',
 153                    pgoff,
 154                    MAJOR(dev), MINOR(dev), ino, &len);
 155
 156         if (file) {
 157                 len = 25 + sizeof(void *) * 6 - len;
 158                 if (len < 1)
 159                         len = 1;
 160                 seq_printf(m, "%*c", len, ' ');
 161                 seq_path(m, &file->f_path, "");
 162         }
 163
 164         seq_putc(m, '\n');
 165         return 0;
 166 }
 167
 168 /*
 169  * display mapping lines for a particular process's /proc/pid/maps
 170  */
 171 static int show_map(struct seq_file *m, void *_p)
 172 {
 173         struct rb_node *p = _p;
 174
 175         return nommu_vma_show(m, rb_entry(p, struct vm_area_struct, vm_rb));
 176 }
 177
 178 static void *m_start(struct seq_file *m, loff_t *pos)
 179 {
 180         struct proc_maps_private *priv = m->private;
 181         struct mm_struct *mm;
 182         struct rb_node *p;
 183         loff_t n = *pos;
 184
 185         /* pin the task and mm whilst we play with them */
 186         priv->task = get_pid_task(priv->pid, PIDTYPE_PID);
 187         if (!priv->task)
 188                 return NULL;
 189
 190         mm = mm_for_maps(priv->task);
 191         if (!mm) {
 192                 put_task_struct(priv->task);
 193                 priv->task = NULL;
 194                 return NULL;
 195         }
 196         down_read(&mm->mmap_sem);
 197
 198         /* start from the Nth VMA */
 199         for (p = rb_first(&mm->mm_rb); p; p = rb_next(p))
 200                 if (n-- == 0)
 201                         return p;
 202         return NULL;
 203 }
 204
 205 static void m_stop(struct seq_file *m, void *_vml)
 206 {
 207         struct proc_maps_private *priv = m->private;
 208
 209         if (priv->task) {
 210                 struct mm_struct *mm = priv->task->mm;
 211                 up_read(&mm->mmap_sem);
 212                 mmput(mm);
 213                 put_task_struct(priv->task);
 214         }
 215 }
 216
 217 static void *m_next(struct seq_file *m, void *_p, loff_t *pos)
 218 {
 219         struct rb_node *p = _p;
 220
 221         (*pos)++;
 222         return p ? rb_next(p) : NULL;
 223 }
 224
 225 static const struct seq_operations proc_pid_maps_ops = {
 226         .start  = m_start,
 227         .next   = m_next,
 228         .stop   = m_stop,
 229         .show   = show_map
 230 };
 231
 232 static int maps_open(struct inode *inode, struct file *file)
 233 {
 234         struct proc_maps_private *priv;
 235         int ret = -ENOMEM;
 236
 237         priv = kzalloc(sizeof(*priv), GFP_KERNEL);
 238         if (priv) {
 239                 priv->pid = proc_pid(inode);
 240                 ret = seq_open(file, &proc_pid_maps_ops);
 241                 if (!ret) {
 242                         struct seq_file *m = file->private_data;
 243                         m->private = priv;
 244                 } else {
 245                         kfree(priv);
 246                 }
 247         }
 248         return ret;
 249 }
 250
 251 const struct file_operations proc_maps_operations = {
 252         .open           = maps_open,
 253         .read           = seq_read,
 254         .llseek         = seq_lseek,
 255         .release        = seq_release_private,
 256 };
 257