fs/proc/task_mmu.c

   1 #include <linux/mm.h>
   2 #include <linux/hugetlb.h>
   3 #include <linux/mount.h>
   4 #include <linux/seq_file.h>
   5 #include <linux/highmem.h>
   6 #include <linux/ptrace.h>
   7 #include <linux/pagemap.h>
   8 #include <linux/mempolicy.h>
   9
  10 #include <asm/elf.h>
  11 #include <asm/uaccess.h>
  12 #include <asm/tlbflush.h>
  13 #include "internal.h"
  14
  15 char *task_mem(struct mm_struct *mm, char *buffer)
  16 {
  17         unsigned long data, text, lib;
  18         unsigned long hiwater_vm, total_vm, hiwater_rss, total_rss;
  19
  20         /*
  21          * Note: to minimize their overhead, mm maintains hiwater_vm and
  22          * hiwater_rss only when about to *lower* total_vm or rss.  Any
  23          * collector of these hiwater stats must therefore get total_vm
  24          * and rss too, which will usually be the higher.  Barriers? not
  25          * worth the effort, such snapshots can always be inconsistent.
  26          */
  27         hiwater_vm = total_vm = mm->total_vm;
  28         if (hiwater_vm < mm->hiwater_vm)
  29                 hiwater_vm = mm->hiwater_vm;
  30         hiwater_rss = total_rss = get_mm_rss(mm);
  31         if (hiwater_rss < mm->hiwater_rss)
  32                 hiwater_rss = mm->hiwater_rss;
  33
  34         data = mm->total_vm - mm->shared_vm - mm->stack_vm;
  35         text = (PAGE_ALIGN(mm->end_code) - (mm->start_code & PAGE_MASK)) >> 10;
  36         lib = (mm->exec_vm << (PAGE_SHIFT-10)) - text;
  37         buffer += sprintf(buffer,
  38                 "VmPeak:\t%8lu kB\n"
  39                 "VmSize:\t%8lu kB\n"
  40                 "VmLck:\t%8lu kB\n"
  41                 "VmHWM:\t%8lu kB\n"
  42                 "VmRSS:\t%8lu kB\n"
  43                 "VmData:\t%8lu kB\n"
  44                 "VmStk:\t%8lu kB\n"
  45                 "VmExe:\t%8lu kB\n"
  46                 "VmLib:\t%8lu kB\n"
  47                 "VmPTE:\t%8lu kB\n",
  48                 hiwater_vm << (PAGE_SHIFT-10),
  49                 (total_vm - mm->reserved_vm) << (PAGE_SHIFT-10),
  50                 mm->locked_vm << (PAGE_SHIFT-10),
  51                 hiwater_rss << (PAGE_SHIFT-10),
  52                 total_rss << (PAGE_SHIFT-10),
  53                 data << (PAGE_SHIFT-10),
  54                 mm->stack_vm << (PAGE_SHIFT-10), text, lib,
  55                 (PTRS_PER_PTE*sizeof(pte_t)*mm->nr_ptes) >> 10);
  56         return buffer;
  57 }
  58
  59 unsigned long task_vsize(struct mm_struct *mm)
  60 {
  61         return PAGE_SIZE * mm->total_vm;
  62 }
  63
  64 int task_statm(struct mm_struct *mm, int *shared, int *text,
  65                int *data, int *resident)
  66 {
  67         *shared = get_mm_counter(mm, file_rss);
  68         *text = (PAGE_ALIGN(mm->end_code) - (mm->start_code & PAGE_MASK))
  69                                                                 >> PAGE_SHIFT;
  70         *data = mm->total_vm - mm->shared_vm;
  71         *resident = *shared + get_mm_counter(mm, anon_rss);
  72         return mm->total_vm;
  73 }
  74
  75 int proc_exe_link(struct inode *inode, struct dentry **dentry, struct vfsmount **mnt)
  76 {
  77         struct vm_area_struct * vma;
  78         int result = -ENOENT;
  79         struct task_struct *task = get_proc_task(inode);
  80         struct mm_struct * mm = NULL;
  81
  82         if (task) {
  83                 mm = get_task_mm(task);
  84                 put_task_struct(task);
  85         }
  86         if (!mm)
  87                 goto out;
  88         down_read(&mm->mmap_sem);
  89
  90         vma = mm->mmap;
  91         while (vma) {
  92                 if ((vma->vm_flags & VM_EXECUTABLE) && vma->vm_file)
  93                         break;
  94                 vma = vma->vm_next;
  95         }
  96
  97         if (vma) {
  98                 *mnt = mntget(vma->vm_file->f_path.mnt);
  99                 *dentry = dget(vma->vm_file->f_path.dentry);
 100                 result = 0;
 101         }
 102
 103         up_read(&mm->mmap_sem);
 104         mmput(mm);
 105 out:
 106         return result;
 107 }
 108
 109 static void pad_len_spaces(struct seq_file *m, int len)
 110 {
 111         len = 25 + sizeof(void*) * 6 - len;
 112         if (len < 1)
 113                 len = 1;
 114         seq_printf(m, "%*c", len, ' ');
 115 }
 116
 117 struct mem_size_stats
 118 {
 119         unsigned long resident;
 120         unsigned long shared_clean;
 121         unsigned long shared_dirty;
 122         unsigned long private_clean;
 123         unsigned long private_dirty;
 124         unsigned long referenced;
 125 };
 126
 127 struct pmd_walker {
 128         struct vm_area_struct *vma;
 129         void *private;
 130         void (*action)(struct vm_area_struct *, pmd_t *, unsigned long,
 131                        unsigned long, void *);
 132 };
 133
 134 static int show_map_internal(struct seq_file *m, void *v, struct mem_size_stats *mss)
 135 {
 136         struct proc_maps_private *priv = m->private;
 137         struct task_struct *task = priv->task;
 138         struct vm_area_struct *vma = v;
 139         struct mm_struct *mm = vma->vm_mm;
 140         struct file *file = vma->vm_file;
 141         int flags = vma->vm_flags;
 142         unsigned long ino = 0;
 143         dev_t dev = 0;
 144         int len;
 145
 146         if (maps_protect && !ptrace_may_attach(task))
 147                 return -EACCES;
 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         }
 154
 155         seq_printf(m, "%08lx-%08lx %c%c%c%c %08lx %02x:%02x %lu %n",
 156                         vma->vm_start,
 157                         vma->vm_end,
 158                         flags & VM_READ ? 'r' : '-',
 159                         flags & VM_WRITE ? 'w' : '-',
 160                         flags & VM_EXEC ? 'x' : '-',
 161                         flags & VM_MAYSHARE ? 's' : 'p',
 162                         vma->vm_pgoff << PAGE_SHIFT,
 163                         MAJOR(dev), MINOR(dev), ino, &len);
 164
 165         /*
 166          * Print the dentry name for named mappings, and a
 167          * special [heap] marker for the heap:
 168          */
 169         if (file) {
 170                 pad_len_spaces(m, len);
 171                 seq_path(m, file->f_path.mnt, file->f_path.dentry, "\n");
 172         } else {
 173                 const char *name = arch_vma_name(vma);
 174                 if (!name) {
 175                         if (mm) {
 176                                 if (vma->vm_start <= mm->start_brk &&
 177                                                 vma->vm_end >= mm->brk) {
 178                                         name = "[heap]";
 179                                 } else if (vma->vm_start <= mm->start_stack &&
 180                                            vma->vm_end >= mm->start_stack) {
 181                                         name = "[stack]";
 182                                 }
 183                         } else {
 184                                 name = "[vdso]";
 185                         }
 186                 }
 187                 if (name) {
 188                         pad_len_spaces(m, len);
 189                         seq_puts(m, name);
 190                 }
 191         }
 192         seq_putc(m, '\n');
 193
 194         if (mss)
 195                 seq_printf(m,
 196                            "Size:           %8lu kB\n"
 197                            "Rss:            %8lu kB\n"
 198                            "Shared_Clean:   %8lu kB\n"
 199                            "Shared_Dirty:   %8lu kB\n"
 200                            "Private_Clean:  %8lu kB\n"
 201                            "Private_Dirty:  %8lu kB\n"
 202                            "Referenced:     %8lu kB\n",
 203                            (vma->vm_end - vma->vm_start) >> 10,
 204                            mss->resident >> 10,
 205                            mss->shared_clean  >> 10,
 206                            mss->shared_dirty  >> 10,
 207                            mss->private_clean >> 10,
 208                            mss->private_dirty >> 10,
 209                            mss->referenced >> 10);
 210
 211         if (m->count < m->size)  /* vma is copied successfully */
 212                 m->version = (vma != get_gate_vma(task))? vma->vm_start: 0;
 213         return 0;
 214 }
 215
 216 static int show_map(struct seq_file *m, void *v)
 217 {
 218         return show_map_internal(m, v, NULL);
 219 }
 220
 221 static void smaps_pte_range(struct vm_area_struct *vma, pmd_t *pmd,
 222                             unsigned long addr, unsigned long end,
 223                             void *private)
 224 {
 225         struct mem_size_stats *mss = private;
 226         pte_t *pte, ptent;
 227         spinlock_t *ptl;
 228         struct page *page;
 229
 230         pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl);
 231         for (; addr != end; pte++, addr += PAGE_SIZE) {
 232                 ptent = *pte;
 233                 if (!pte_present(ptent))
 234                         continue;
 235
 236                 mss->resident += PAGE_SIZE;
 237
 238                 page = vm_normal_page(vma, addr, ptent);
 239                 if (!page)
 240                         continue;
 241
 242                 /* Accumulate the size in pages that have been accessed. */
 243                 if (pte_young(ptent) || PageReferenced(page))
 244                         mss->referenced += PAGE_SIZE;
 245                 if (page_mapcount(page) >= 2) {
 246                         if (pte_dirty(ptent))
 247                                 mss->shared_dirty += PAGE_SIZE;
 248                         else
 249                                 mss->shared_clean += PAGE_SIZE;
 250                 } else {
 251                         if (pte_dirty(ptent))
 252                                 mss->private_dirty += PAGE_SIZE;
 253                         else
 254                                 mss->private_clean += PAGE_SIZE;
 255                 }
 256         }
 257         pte_unmap_unlock(pte - 1, ptl);
 258         cond_resched();
 259 }
 260
 261 static void clear_refs_pte_range(struct vm_area_struct *vma, pmd_t *pmd,
 262                                  unsigned long addr, unsigned long end,
 263                                  void *private)
 264 {
 265         pte_t *pte, ptent;
 266         spinlock_t *ptl;
 267         struct page *page;
 268
 269         pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl);
 270         for (; addr != end; pte++, addr += PAGE_SIZE) {
 271                 ptent = *pte;
 272                 if (!pte_present(ptent))
 273                         continue;
 274
 275                 page = vm_normal_page(vma, addr, ptent);
 276                 if (!page)
 277                         continue;
 278
 279                 /* Clear accessed and referenced bits. */
 280                 ptep_test_and_clear_young(vma, addr, pte);
 281                 ClearPageReferenced(page);
 282         }
 283         pte_unmap_unlock(pte - 1, ptl);
 284         cond_resched();
 285 }
 286
 287 static inline void walk_pmd_range(struct pmd_walker *walker, pud_t *pud,
 288                                   unsigned long addr, unsigned long end)
 289 {
 290         pmd_t *pmd;
 291         unsigned long next;
 292
 293         for (pmd = pmd_offset(pud, addr); addr != end;
 294              pmd++, addr = next) {
 295                 next = pmd_addr_end(addr, end);
 296                 if (pmd_none_or_clear_bad(pmd))
 297                         continue;
 298                 walker->action(walker->vma, pmd, addr, next, walker->private);
 299         }
 300 }
 301
 302 static inline void walk_pud_range(struct pmd_walker *walker, pgd_t *pgd,
 303                                   unsigned long addr, unsigned long end)
 304 {
 305         pud_t *pud;
 306         unsigned long next;
 307
 308         for (pud = pud_offset(pgd, addr); addr != end;
 309              pud++, addr = next) {
 310                 next = pud_addr_end(addr, end);
 311                 if (pud_none_or_clear_bad(pud))
 312                         continue;
 313                 walk_pmd_range(walker, pud, addr, next);
 314         }
 315 }
 316
 317 /*
 318  * walk_page_range - walk the page tables of a VMA with a callback
 319  * @vma - VMA to walk
 320  * @action - callback invoked for every bottom-level (PTE) page table
 321  * @private - private data passed to the callback function
 322  *
 323  * Recursively walk the page table for the memory area in a VMA, calling
 324  * a callback for every bottom-level (PTE) page table.
 325  */
 326 static inline void walk_page_range(struct vm_area_struct *vma,
 327                                    void (*action)(struct vm_area_struct *,
 328                                                   pmd_t *, unsigned long,
 329                                                   unsigned long, void *),
 330                                    void *private)
 331 {
 332         unsigned long addr = vma->vm_start;
 333         unsigned long end = vma->vm_end;
 334         struct pmd_walker walker = {
 335                 .vma            = vma,
 336                 .private        = private,
 337                 .action         = action,
 338         };
 339         pgd_t *pgd;
 340         unsigned long next;
 341
 342         for (pgd = pgd_offset(vma->vm_mm, addr); addr != end;
 343              pgd++, addr = next) {
 344                 next = pgd_addr_end(addr, end);
 345                 if (pgd_none_or_clear_bad(pgd))
 346                         continue;
 347                 walk_pud_range(&walker, pgd, addr, next);
 348         }
 349 }
 350
 351 static int show_smap(struct seq_file *m, void *v)
 352 {
 353         struct vm_area_struct *vma = v;
 354         struct mem_size_stats mss;
 355
 356         memset(&mss, 0, sizeof mss);
 357         if (vma->vm_mm && !is_vm_hugetlb_page(vma))
 358                 walk_page_range(vma, smaps_pte_range, &mss);
 359         return show_map_internal(m, v, &mss);
 360 }
 361
 362 void clear_refs_smap(struct mm_struct *mm)
 363 {
 364         struct vm_area_struct *vma;
 365
 366         down_read(&mm->mmap_sem);
 367         for (vma = mm->mmap; vma; vma = vma->vm_next)
 368                 if (vma->vm_mm && !is_vm_hugetlb_page(vma))
 369                         walk_page_range(vma, clear_refs_pte_range, NULL);
 370         flush_tlb_mm(mm);
 371         up_read(&mm->mmap_sem);
 372 }
 373
 374 static void *m_start(struct seq_file *m, loff_t *pos)
 375 {
 376         struct proc_maps_private *priv = m->private;
 377         unsigned long last_addr = m->version;
 378         struct mm_struct *mm;
 379         struct vm_area_struct *vma, *tail_vma = NULL;
 380         loff_t l = *pos;
 381
 382         /* Clear the per syscall fields in priv */
 383         priv->task = NULL;
 384         priv->tail_vma = NULL;
 385
 386         /*
 387          * We remember last_addr rather than next_addr to hit with
 388          * mmap_cache most of the time. We have zero last_addr at
 389          * the beginning and also after lseek. We will have -1 last_addr
 390          * after the end of the vmas.
 391          */
 392
 393         if (last_addr == -1UL)
 394                 return NULL;
 395
 396         priv->task = get_pid_task(priv->pid, PIDTYPE_PID);
 397         if (!priv->task)
 398                 return NULL;
 399
 400         mm = mm_for_maps(priv->task);
 401         if (!mm)
 402                 return NULL;
 403
 404         priv->tail_vma = tail_vma = get_gate_vma(priv->task);
 405
 406         /* Start with last addr hint */
 407         if (last_addr && (vma = find_vma(mm, last_addr))) {
 408                 vma = vma->vm_next;
 409                 goto out;
 410         }
 411
 412         /*
 413          * Check the vma index is within the range and do
 414          * sequential scan until m_index.
 415          */
 416         vma = NULL;
 417         if ((unsigned long)l < mm->map_count) {
 418                 vma = mm->mmap;
 419                 while (l-- && vma)
 420                         vma = vma->vm_next;
 421                 goto out;
 422         }
 423
 424         if (l != mm->map_count)
 425                 tail_vma = NULL; /* After gate vma */
 426
 427 out:
 428         if (vma)
 429                 return vma;
 430
 431         /* End of vmas has been reached */
 432         m->version = (tail_vma != NULL)? 0: -1UL;
 433         up_read(&mm->mmap_sem);
 434         mmput(mm);
 435         return tail_vma;
 436 }
 437
 438 static void vma_stop(struct proc_maps_private *priv, struct vm_area_struct *vma)
 439 {
 440         if (vma && vma != priv->tail_vma) {
 441                 struct mm_struct *mm = vma->vm_mm;
 442                 up_read(&mm->mmap_sem);
 443                 mmput(mm);
 444         }
 445 }
 446
 447 static void *m_next(struct seq_file *m, void *v, loff_t *pos)
 448 {
 449         struct proc_maps_private *priv = m->private;
 450         struct vm_area_struct *vma = v;
 451         struct vm_area_struct *tail_vma = priv->tail_vma;
 452
 453         (*pos)++;
 454         if (vma && (vma != tail_vma) && vma->vm_next)
 455                 return vma->vm_next;
 456         vma_stop(priv, vma);
 457         return (vma != tail_vma)? tail_vma: NULL;
 458 }
 459
 460 static void m_stop(struct seq_file *m, void *v)
 461 {
 462         struct proc_maps_private *priv = m->private;
 463         struct vm_area_struct *vma = v;
 464
 465         vma_stop(priv, vma);
 466         if (priv->task)
 467                 put_task_struct(priv->task);
 468 }
 469
 470 static struct seq_operations proc_pid_maps_op = {
 471         .start  = m_start,
 472         .next   = m_next,
 473         .stop   = m_stop,
 474         .show   = show_map
 475 };
 476
 477 static struct seq_operations proc_pid_smaps_op = {
 478         .start  = m_start,
 479         .next   = m_next,
 480         .stop   = m_stop,
 481         .show   = show_smap
 482 };
 483
 484 static int do_maps_open(struct inode *inode, struct file *file,
 485                         struct seq_operations *ops)
 486 {
 487         struct proc_maps_private *priv;
 488         int ret = -ENOMEM;
 489         priv = kzalloc(sizeof(*priv), GFP_KERNEL);
 490         if (priv) {
 491                 priv->pid = proc_pid(inode);
 492                 ret = seq_open(file, ops);
 493                 if (!ret) {
 494                         struct seq_file *m = file->private_data;
 495                         m->private = priv;
 496                 } else {
 497                         kfree(priv);
 498                 }
 499         }
 500         return ret;
 501 }
 502
 503 static int maps_open(struct inode *inode, struct file *file)
 504 {
 505         return do_maps_open(inode, file, &proc_pid_maps_op);
 506 }
 507
 508 const struct file_operations proc_maps_operations = {
 509         .open           = maps_open,
 510         .read           = seq_read,
 511         .llseek         = seq_lseek,
 512         .release        = seq_release_private,
 513 };
 514
 515 #ifdef CONFIG_NUMA
 516 extern int show_numa_map(struct seq_file *m, void *v);
 517
 518 static int show_numa_map_checked(struct seq_file *m, void *v)
 519 {
 520         struct proc_maps_private *priv = m->private;
 521         struct task_struct *task = priv->task;
 522
 523         if (maps_protect && !ptrace_may_attach(task))
 524                 return -EACCES;
 525
 526         return show_numa_map(m, v);
 527 }
 528
 529 static struct seq_operations proc_pid_numa_maps_op = {
 530         .start  = m_start,
 531         .next   = m_next,
 532         .stop   = m_stop,
 533         .show   = show_numa_map_checked
 534 };
 535
 536 static int numa_maps_open(struct inode *inode, struct file *file)
 537 {
 538         return do_maps_open(inode, file, &proc_pid_numa_maps_op);
 539 }
 540
 541 const struct file_operations proc_numa_maps_operations = {
 542         .open           = numa_maps_open,
 543         .read           = seq_read,
 544         .llseek         = seq_lseek,
 545         .release        = seq_release_private,
 546 };
 547 #endif
 548
 549 static int smaps_open(struct inode *inode, struct file *file)
 550 {
 551         return do_maps_open(inode, file, &proc_pid_smaps_op);
 552 }
 553
 554 const struct file_operations proc_smaps_operations = {
 555         .open           = smaps_open,
 556         .read           = seq_read,
 557         .llseek         = seq_lseek,
 558         .release        = seq_release_private,
 559 };