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/fs/proc/task_mmu.c

https://bitbucket.org/cyanogenmod/android_kernel_asus_tf300t
C | 1113 lines | 863 code | 147 blank | 103 comment | 166 complexity | 986c8c81b1ef15dce5ea2cf372eb0eb0 MD5 | raw file
Possible License(s): LGPL-2.0, AGPL-1.0, GPL-2.0
   1#include <linux/mm.h>
   2#include <linux/hugetlb.h>
   3#include <linux/huge_mm.h>
   4#include <linux/mount.h>
   5#include <linux/seq_file.h>
   6#include <linux/highmem.h>
   7#include <linux/ptrace.h>
   8#include <linux/slab.h>
   9#include <linux/pagemap.h>
  10#include <linux/mempolicy.h>
  11#include <linux/rmap.h>
  12#include <linux/swap.h>
  13#include <linux/swapops.h>
  14
  15#include <asm/elf.h>
  16#include <asm/uaccess.h>
  17#include <asm/tlbflush.h>
  18#include "internal.h"
  19
  20void task_mem(struct seq_file *m, struct mm_struct *mm)
  21{
  22	unsigned long data, text, lib, swap;
  23	unsigned long hiwater_vm, total_vm, hiwater_rss, total_rss;
  24
  25	/*
  26	 * Note: to minimize their overhead, mm maintains hiwater_vm and
  27	 * hiwater_rss only when about to *lower* total_vm or rss.  Any
  28	 * collector of these hiwater stats must therefore get total_vm
  29	 * and rss too, which will usually be the higher.  Barriers? not
  30	 * worth the effort, such snapshots can always be inconsistent.
  31	 */
  32	hiwater_vm = total_vm = mm->total_vm;
  33	if (hiwater_vm < mm->hiwater_vm)
  34		hiwater_vm = mm->hiwater_vm;
  35	hiwater_rss = total_rss = get_mm_rss(mm);
  36	if (hiwater_rss < mm->hiwater_rss)
  37		hiwater_rss = mm->hiwater_rss;
  38
  39	data = mm->total_vm - mm->shared_vm - mm->stack_vm;
  40	text = (PAGE_ALIGN(mm->end_code) - (mm->start_code & PAGE_MASK)) >> 10;
  41	lib = (mm->exec_vm << (PAGE_SHIFT-10)) - text;
  42	swap = get_mm_counter(mm, MM_SWAPENTS);
  43	seq_printf(m,
  44		"VmPeak:\t%8lu kB\n"
  45		"VmSize:\t%8lu kB\n"
  46		"VmLck:\t%8lu kB\n"
  47		"VmHWM:\t%8lu kB\n"
  48		"VmRSS:\t%8lu kB\n"
  49		"VmData:\t%8lu kB\n"
  50		"VmStk:\t%8lu kB\n"
  51		"VmExe:\t%8lu kB\n"
  52		"VmLib:\t%8lu kB\n"
  53		"VmPTE:\t%8lu kB\n"
  54		"VmSwap:\t%8lu kB\n",
  55		hiwater_vm << (PAGE_SHIFT-10),
  56		(total_vm - mm->reserved_vm) << (PAGE_SHIFT-10),
  57		mm->locked_vm << (PAGE_SHIFT-10),
  58		hiwater_rss << (PAGE_SHIFT-10),
  59		total_rss << (PAGE_SHIFT-10),
  60		data << (PAGE_SHIFT-10),
  61		mm->stack_vm << (PAGE_SHIFT-10), text, lib,
  62		(PTRS_PER_PTE*sizeof(pte_t)*mm->nr_ptes) >> 10,
  63		swap << (PAGE_SHIFT-10));
  64}
  65
  66unsigned long task_vsize(struct mm_struct *mm)
  67{
  68	return PAGE_SIZE * mm->total_vm;
  69}
  70
  71unsigned long task_statm(struct mm_struct *mm,
  72			 unsigned long *shared, unsigned long *text,
  73			 unsigned long *data, unsigned long *resident)
  74{
  75	*shared = get_mm_counter(mm, MM_FILEPAGES);
  76	*text = (PAGE_ALIGN(mm->end_code) - (mm->start_code & PAGE_MASK))
  77								>> PAGE_SHIFT;
  78	*data = mm->total_vm - mm->shared_vm;
  79	*resident = *shared + get_mm_counter(mm, MM_ANONPAGES);
  80	return mm->total_vm;
  81}
  82
  83static void pad_len_spaces(struct seq_file *m, int len)
  84{
  85	len = 25 + sizeof(void*) * 6 - len;
  86	if (len < 1)
  87		len = 1;
  88	seq_printf(m, "%*c", len, ' ');
  89}
  90
  91static void vma_stop(struct proc_maps_private *priv, struct vm_area_struct *vma)
  92{
  93	if (vma && vma != priv->tail_vma) {
  94		struct mm_struct *mm = vma->vm_mm;
  95		up_read(&mm->mmap_sem);
  96		mmput(mm);
  97	}
  98}
  99
 100static void *m_start(struct seq_file *m, loff_t *pos)
 101{
 102	struct proc_maps_private *priv = m->private;
 103	unsigned long last_addr = m->version;
 104	struct mm_struct *mm;
 105	struct vm_area_struct *vma, *tail_vma = NULL;
 106	loff_t l = *pos;
 107
 108	/* Clear the per syscall fields in priv */
 109	priv->task = NULL;
 110	priv->tail_vma = NULL;
 111
 112	/*
 113	 * We remember last_addr rather than next_addr to hit with
 114	 * mmap_cache most of the time. We have zero last_addr at
 115	 * the beginning and also after lseek. We will have -1 last_addr
 116	 * after the end of the vmas.
 117	 */
 118
 119	if (last_addr == -1UL)
 120		return NULL;
 121
 122	priv->task = get_pid_task(priv->pid, PIDTYPE_PID);
 123	if (!priv->task)
 124		return ERR_PTR(-ESRCH);
 125
 126	mm = mm_for_maps(priv->task);
 127	if (!mm || IS_ERR(mm))
 128		return mm;
 129	down_read(&mm->mmap_sem);
 130
 131	tail_vma = get_gate_vma(priv->task->mm);
 132	priv->tail_vma = tail_vma;
 133
 134	/* Start with last addr hint */
 135	vma = find_vma(mm, last_addr);
 136	if (last_addr && vma) {
 137		vma = vma->vm_next;
 138		goto out;
 139	}
 140
 141	/*
 142	 * Check the vma index is within the range and do
 143	 * sequential scan until m_index.
 144	 */
 145	vma = NULL;
 146	if ((unsigned long)l < mm->map_count) {
 147		vma = mm->mmap;
 148		while (l-- && vma)
 149			vma = vma->vm_next;
 150		goto out;
 151	}
 152
 153	if (l != mm->map_count)
 154		tail_vma = NULL; /* After gate vma */
 155
 156out:
 157	if (vma)
 158		return vma;
 159
 160	/* End of vmas has been reached */
 161	m->version = (tail_vma != NULL)? 0: -1UL;
 162	up_read(&mm->mmap_sem);
 163	mmput(mm);
 164	return tail_vma;
 165}
 166
 167static void *m_next(struct seq_file *m, void *v, loff_t *pos)
 168{
 169	struct proc_maps_private *priv = m->private;
 170	struct vm_area_struct *vma = v;
 171	struct vm_area_struct *tail_vma = priv->tail_vma;
 172
 173	(*pos)++;
 174	if (vma && (vma != tail_vma) && vma->vm_next)
 175		return vma->vm_next;
 176	vma_stop(priv, vma);
 177	return (vma != tail_vma)? tail_vma: NULL;
 178}
 179
 180static void m_stop(struct seq_file *m, void *v)
 181{
 182	struct proc_maps_private *priv = m->private;
 183	struct vm_area_struct *vma = v;
 184
 185	if (!IS_ERR(vma))
 186		vma_stop(priv, vma);
 187	if (priv->task)
 188		put_task_struct(priv->task);
 189}
 190
 191static int do_maps_open(struct inode *inode, struct file *file,
 192			const struct seq_operations *ops)
 193{
 194	struct proc_maps_private *priv;
 195	int ret = -ENOMEM;
 196	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
 197	if (priv) {
 198		priv->pid = proc_pid(inode);
 199		ret = seq_open(file, ops);
 200		if (!ret) {
 201			struct seq_file *m = file->private_data;
 202			m->private = priv;
 203		} else {
 204			kfree(priv);
 205		}
 206	}
 207	return ret;
 208}
 209
 210static void show_map_vma(struct seq_file *m, struct vm_area_struct *vma)
 211{
 212	struct mm_struct *mm = vma->vm_mm;
 213	struct file *file = vma->vm_file;
 214	vm_flags_t flags = vma->vm_flags;
 215	unsigned long ino = 0;
 216	unsigned long long pgoff = 0;
 217	unsigned long start, end;
 218	dev_t dev = 0;
 219	int len;
 220
 221	if (file) {
 222		struct inode *inode = vma->vm_file->f_path.dentry->d_inode;
 223		dev = inode->i_sb->s_dev;
 224		ino = inode->i_ino;
 225		pgoff = ((loff_t)vma->vm_pgoff) << PAGE_SHIFT;
 226	}
 227
 228	/* We don't show the stack guard page in /proc/maps */
 229	start = vma->vm_start;
 230	if (stack_guard_page_start(vma, start))
 231		start += PAGE_SIZE;
 232	end = vma->vm_end;
 233	if (stack_guard_page_end(vma, end))
 234		end -= PAGE_SIZE;
 235
 236	seq_printf(m, "%08lx-%08lx %c%c%c%c %08llx %02x:%02x %lu %n",
 237			start,
 238			end,
 239			flags & VM_READ ? 'r' : '-',
 240			flags & VM_WRITE ? 'w' : '-',
 241			flags & VM_EXEC ? 'x' : '-',
 242			flags & VM_MAYSHARE ? 's' : 'p',
 243			pgoff,
 244			MAJOR(dev), MINOR(dev), ino, &len);
 245
 246	/*
 247	 * Print the dentry name for named mappings, and a
 248	 * special [heap] marker for the heap:
 249	 */
 250	if (file) {
 251		pad_len_spaces(m, len);
 252		seq_path(m, &file->f_path, "\n");
 253	} else {
 254		const char *name = arch_vma_name(vma);
 255		if (!name) {
 256			if (mm) {
 257				if (vma->vm_start <= mm->brk &&
 258						vma->vm_end >= mm->start_brk) {
 259					name = "[heap]";
 260				} else if (vma->vm_start <= mm->start_stack &&
 261					   vma->vm_end >= mm->start_stack) {
 262					name = "[stack]";
 263				}
 264			} else {
 265				name = "[vdso]";
 266			}
 267		}
 268		if (name) {
 269			pad_len_spaces(m, len);
 270			seq_puts(m, name);
 271		}
 272	}
 273	seq_putc(m, '\n');
 274}
 275
 276static int show_map(struct seq_file *m, void *v)
 277{
 278	struct vm_area_struct *vma = v;
 279	struct proc_maps_private *priv = m->private;
 280	struct task_struct *task = priv->task;
 281
 282	show_map_vma(m, vma);
 283
 284	if (m->count < m->size)  /* vma is copied successfully */
 285		m->version = (vma != get_gate_vma(task->mm))
 286			? vma->vm_start : 0;
 287	return 0;
 288}
 289
 290static const struct seq_operations proc_pid_maps_op = {
 291	.start	= m_start,
 292	.next	= m_next,
 293	.stop	= m_stop,
 294	.show	= show_map
 295};
 296
 297static int maps_open(struct inode *inode, struct file *file)
 298{
 299	return do_maps_open(inode, file, &proc_pid_maps_op);
 300}
 301
 302const struct file_operations proc_maps_operations = {
 303	.open		= maps_open,
 304	.read		= seq_read,
 305	.llseek		= seq_lseek,
 306	.release	= seq_release_private,
 307};
 308
 309/*
 310 * Proportional Set Size(PSS): my share of RSS.
 311 *
 312 * PSS of a process is the count of pages it has in memory, where each
 313 * page is divided by the number of processes sharing it.  So if a
 314 * process has 1000 pages all to itself, and 1000 shared with one other
 315 * process, its PSS will be 1500.
 316 *
 317 * To keep (accumulated) division errors low, we adopt a 64bit
 318 * fixed-point pss counter to minimize division errors. So (pss >>
 319 * PSS_SHIFT) would be the real byte count.
 320 *
 321 * A shift of 12 before division means (assuming 4K page size):
 322 * 	- 1M 3-user-pages add up to 8KB errors;
 323 * 	- supports mapcount up to 2^24, or 16M;
 324 * 	- supports PSS up to 2^52 bytes, or 4PB.
 325 */
 326#define PSS_SHIFT 12
 327
 328#ifdef CONFIG_PROC_PAGE_MONITOR
 329struct mem_size_stats {
 330	struct vm_area_struct *vma;
 331	unsigned long resident;
 332	unsigned long shared_clean;
 333	unsigned long shared_dirty;
 334	unsigned long private_clean;
 335	unsigned long private_dirty;
 336	unsigned long referenced;
 337	unsigned long anonymous;
 338	unsigned long anonymous_thp;
 339	unsigned long swap;
 340	u64 pss;
 341};
 342
 343
 344static void smaps_pte_entry(pte_t ptent, unsigned long addr,
 345		unsigned long ptent_size, struct mm_walk *walk)
 346{
 347	struct mem_size_stats *mss = walk->private;
 348	struct vm_area_struct *vma = mss->vma;
 349	struct page *page;
 350	int mapcount;
 351
 352	if (is_swap_pte(ptent)) {
 353		mss->swap += ptent_size;
 354		return;
 355	}
 356
 357	if (!pte_present(ptent))
 358		return;
 359
 360	page = vm_normal_page(vma, addr, ptent);
 361	if (!page)
 362		return;
 363
 364	if (PageAnon(page))
 365		mss->anonymous += ptent_size;
 366
 367	mss->resident += ptent_size;
 368	/* Accumulate the size in pages that have been accessed. */
 369	if (pte_young(ptent) || PageReferenced(page))
 370		mss->referenced += ptent_size;
 371	mapcount = page_mapcount(page);
 372	if (mapcount >= 2) {
 373		if (pte_dirty(ptent) || PageDirty(page))
 374			mss->shared_dirty += ptent_size;
 375		else
 376			mss->shared_clean += ptent_size;
 377		mss->pss += (ptent_size << PSS_SHIFT) / mapcount;
 378	} else {
 379		if (pte_dirty(ptent) || PageDirty(page))
 380			mss->private_dirty += ptent_size;
 381		else
 382			mss->private_clean += ptent_size;
 383		mss->pss += (ptent_size << PSS_SHIFT);
 384	}
 385}
 386
 387static int smaps_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end,
 388			   struct mm_walk *walk)
 389{
 390	struct mem_size_stats *mss = walk->private;
 391	struct vm_area_struct *vma = mss->vma;
 392	pte_t *pte;
 393	spinlock_t *ptl;
 394
 395	spin_lock(&walk->mm->page_table_lock);
 396	if (pmd_trans_huge(*pmd)) {
 397		if (pmd_trans_splitting(*pmd)) {
 398			spin_unlock(&walk->mm->page_table_lock);
 399			wait_split_huge_page(vma->anon_vma, pmd);
 400		} else {
 401			smaps_pte_entry(*(pte_t *)pmd, addr,
 402					HPAGE_PMD_SIZE, walk);
 403			spin_unlock(&walk->mm->page_table_lock);
 404			mss->anonymous_thp += HPAGE_PMD_SIZE;
 405			return 0;
 406		}
 407	} else {
 408		spin_unlock(&walk->mm->page_table_lock);
 409	}
 410	/*
 411	 * The mmap_sem held all the way back in m_start() is what
 412	 * keeps khugepaged out of here and from collapsing things
 413	 * in here.
 414	 */
 415	pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl);
 416	for (; addr != end; pte++, addr += PAGE_SIZE)
 417		smaps_pte_entry(*pte, addr, PAGE_SIZE, walk);
 418	pte_unmap_unlock(pte - 1, ptl);
 419	cond_resched();
 420	return 0;
 421}
 422
 423static int show_smap(struct seq_file *m, void *v)
 424{
 425	struct proc_maps_private *priv = m->private;
 426	struct task_struct *task = priv->task;
 427	struct vm_area_struct *vma = v;
 428	struct mem_size_stats mss;
 429	struct mm_walk smaps_walk = {
 430		.pmd_entry = smaps_pte_range,
 431		.mm = vma->vm_mm,
 432		.private = &mss,
 433	};
 434
 435	memset(&mss, 0, sizeof mss);
 436	mss.vma = vma;
 437	/* mmap_sem is held in m_start */
 438	if (vma->vm_mm && !is_vm_hugetlb_page(vma))
 439		walk_page_range(vma->vm_start, vma->vm_end, &smaps_walk);
 440
 441	show_map_vma(m, vma);
 442
 443	seq_printf(m,
 444		   "Size:           %8lu kB\n"
 445		   "Rss:            %8lu kB\n"
 446		   "Pss:            %8lu kB\n"
 447		   "Shared_Clean:   %8lu kB\n"
 448		   "Shared_Dirty:   %8lu kB\n"
 449		   "Private_Clean:  %8lu kB\n"
 450		   "Private_Dirty:  %8lu kB\n"
 451		   "Referenced:     %8lu kB\n"
 452		   "Anonymous:      %8lu kB\n"
 453		   "AnonHugePages:  %8lu kB\n"
 454		   "Swap:           %8lu kB\n"
 455		   "KernelPageSize: %8lu kB\n"
 456		   "MMUPageSize:    %8lu kB\n"
 457		   "Locked:         %8lu kB\n",
 458		   (vma->vm_end - vma->vm_start) >> 10,
 459		   mss.resident >> 10,
 460		   (unsigned long)(mss.pss >> (10 + PSS_SHIFT)),
 461		   mss.shared_clean  >> 10,
 462		   mss.shared_dirty  >> 10,
 463		   mss.private_clean >> 10,
 464		   mss.private_dirty >> 10,
 465		   mss.referenced >> 10,
 466		   mss.anonymous >> 10,
 467		   mss.anonymous_thp >> 10,
 468		   mss.swap >> 10,
 469		   vma_kernel_pagesize(vma) >> 10,
 470		   vma_mmu_pagesize(vma) >> 10,
 471		   (vma->vm_flags & VM_LOCKED) ?
 472			(unsigned long)(mss.pss >> (10 + PSS_SHIFT)) : 0);
 473
 474	if (m->count < m->size)  /* vma is copied successfully */
 475		m->version = (vma != get_gate_vma(task->mm))
 476			? vma->vm_start : 0;
 477	return 0;
 478}
 479
 480static const struct seq_operations proc_pid_smaps_op = {
 481	.start	= m_start,
 482	.next	= m_next,
 483	.stop	= m_stop,
 484	.show	= show_smap
 485};
 486
 487static int smaps_open(struct inode *inode, struct file *file)
 488{
 489	return do_maps_open(inode, file, &proc_pid_smaps_op);
 490}
 491
 492const struct file_operations proc_smaps_operations = {
 493	.open		= smaps_open,
 494	.read		= seq_read,
 495	.llseek		= seq_lseek,
 496	.release	= seq_release_private,
 497};
 498
 499static int clear_refs_pte_range(pmd_t *pmd, unsigned long addr,
 500				unsigned long end, struct mm_walk *walk)
 501{
 502	struct vm_area_struct *vma = walk->private;
 503	pte_t *pte, ptent;
 504	spinlock_t *ptl;
 505	struct page *page;
 506
 507	split_huge_page_pmd(walk->mm, pmd);
 508
 509	pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl);
 510	for (; addr != end; pte++, addr += PAGE_SIZE) {
 511		ptent = *pte;
 512		if (!pte_present(ptent))
 513			continue;
 514
 515		page = vm_normal_page(vma, addr, ptent);
 516		if (!page)
 517			continue;
 518
 519		/* Clear accessed and referenced bits. */
 520		ptep_test_and_clear_young(vma, addr, pte);
 521		ClearPageReferenced(page);
 522	}
 523	pte_unmap_unlock(pte - 1, ptl);
 524	cond_resched();
 525	return 0;
 526}
 527
 528#define CLEAR_REFS_ALL 1
 529#define CLEAR_REFS_ANON 2
 530#define CLEAR_REFS_MAPPED 3
 531
 532static ssize_t clear_refs_write(struct file *file, const char __user *buf,
 533				size_t count, loff_t *ppos)
 534{
 535	struct task_struct *task;
 536	char buffer[PROC_NUMBUF];
 537	struct mm_struct *mm;
 538	struct vm_area_struct *vma;
 539	int type;
 540	int rv;
 541
 542	memset(buffer, 0, sizeof(buffer));
 543	if (count > sizeof(buffer) - 1)
 544		count = sizeof(buffer) - 1;
 545	if (copy_from_user(buffer, buf, count))
 546		return -EFAULT;
 547	rv = kstrtoint(strstrip(buffer), 10, &type);
 548	if (rv < 0)
 549		return rv;
 550	if (type < CLEAR_REFS_ALL || type > CLEAR_REFS_MAPPED)
 551		return -EINVAL;
 552	task = get_proc_task(file->f_path.dentry->d_inode);
 553	if (!task)
 554		return -ESRCH;
 555	mm = get_task_mm(task);
 556	if (mm) {
 557		struct mm_walk clear_refs_walk = {
 558			.pmd_entry = clear_refs_pte_range,
 559			.mm = mm,
 560		};
 561		down_read(&mm->mmap_sem);
 562		for (vma = mm->mmap; vma; vma = vma->vm_next) {
 563			clear_refs_walk.private = vma;
 564			if (is_vm_hugetlb_page(vma))
 565				continue;
 566			/*
 567			 * Writing 1 to /proc/pid/clear_refs affects all pages.
 568			 *
 569			 * Writing 2 to /proc/pid/clear_refs only affects
 570			 * Anonymous pages.
 571			 *
 572			 * Writing 3 to /proc/pid/clear_refs only affects file
 573			 * mapped pages.
 574			 */
 575			if (type == CLEAR_REFS_ANON && vma->vm_file)
 576				continue;
 577			if (type == CLEAR_REFS_MAPPED && !vma->vm_file)
 578				continue;
 579			walk_page_range(vma->vm_start, vma->vm_end,
 580					&clear_refs_walk);
 581		}
 582		flush_tlb_mm(mm);
 583		up_read(&mm->mmap_sem);
 584		mmput(mm);
 585	}
 586	put_task_struct(task);
 587
 588	return count;
 589}
 590
 591const struct file_operations proc_clear_refs_operations = {
 592	.write		= clear_refs_write,
 593	.llseek		= noop_llseek,
 594};
 595
 596struct pagemapread {
 597	int pos, len;
 598	u64 *buffer;
 599};
 600
 601#define PM_ENTRY_BYTES      sizeof(u64)
 602#define PM_STATUS_BITS      3
 603#define PM_STATUS_OFFSET    (64 - PM_STATUS_BITS)
 604#define PM_STATUS_MASK      (((1LL << PM_STATUS_BITS) - 1) << PM_STATUS_OFFSET)
 605#define PM_STATUS(nr)       (((nr) << PM_STATUS_OFFSET) & PM_STATUS_MASK)
 606#define PM_PSHIFT_BITS      6
 607#define PM_PSHIFT_OFFSET    (PM_STATUS_OFFSET - PM_PSHIFT_BITS)
 608#define PM_PSHIFT_MASK      (((1LL << PM_PSHIFT_BITS) - 1) << PM_PSHIFT_OFFSET)
 609#define PM_PSHIFT(x)        (((u64) (x) << PM_PSHIFT_OFFSET) & PM_PSHIFT_MASK)
 610#define PM_PFRAME_MASK      ((1LL << PM_PSHIFT_OFFSET) - 1)
 611#define PM_PFRAME(x)        ((x) & PM_PFRAME_MASK)
 612
 613#define PM_PRESENT          PM_STATUS(4LL)
 614#define PM_SWAP             PM_STATUS(2LL)
 615#define PM_NOT_PRESENT      PM_PSHIFT(PAGE_SHIFT)
 616#define PM_END_OF_BUFFER    1
 617
 618static int add_to_pagemap(unsigned long addr, u64 pfn,
 619			  struct pagemapread *pm)
 620{
 621	pm->buffer[pm->pos++] = pfn;
 622	if (pm->pos >= pm->len)
 623		return PM_END_OF_BUFFER;
 624	return 0;
 625}
 626
 627static int pagemap_pte_hole(unsigned long start, unsigned long end,
 628				struct mm_walk *walk)
 629{
 630	struct pagemapread *pm = walk->private;
 631	unsigned long addr;
 632	int err = 0;
 633	for (addr = start; addr < end; addr += PAGE_SIZE) {
 634		err = add_to_pagemap(addr, PM_NOT_PRESENT, pm);
 635		if (err)
 636			break;
 637	}
 638	return err;
 639}
 640
 641static u64 swap_pte_to_pagemap_entry(pte_t pte)
 642{
 643	swp_entry_t e = pte_to_swp_entry(pte);
 644	return swp_type(e) | (swp_offset(e) << MAX_SWAPFILES_SHIFT);
 645}
 646
 647static u64 pte_to_pagemap_entry(pte_t pte)
 648{
 649	u64 pme = 0;
 650	if (is_swap_pte(pte))
 651		pme = PM_PFRAME(swap_pte_to_pagemap_entry(pte))
 652			| PM_PSHIFT(PAGE_SHIFT) | PM_SWAP;
 653	else if (pte_present(pte))
 654		pme = PM_PFRAME(pte_pfn(pte))
 655			| PM_PSHIFT(PAGE_SHIFT) | PM_PRESENT;
 656	return pme;
 657}
 658
 659static int pagemap_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end,
 660			     struct mm_walk *walk)
 661{
 662	struct vm_area_struct *vma;
 663	struct pagemapread *pm = walk->private;
 664	pte_t *pte;
 665	int err = 0;
 666
 667	split_huge_page_pmd(walk->mm, pmd);
 668
 669	/* find the first VMA at or above 'addr' */
 670	vma = find_vma(walk->mm, addr);
 671	for (; addr != end; addr += PAGE_SIZE) {
 672		u64 pfn = PM_NOT_PRESENT;
 673
 674		/* check to see if we've left 'vma' behind
 675		 * and need a new, higher one */
 676		if (vma && (addr >= vma->vm_end))
 677			vma = find_vma(walk->mm, addr);
 678
 679		/* check that 'vma' actually covers this address,
 680		 * and that it isn't a huge page vma */
 681		if (vma && (vma->vm_start <= addr) &&
 682		    !is_vm_hugetlb_page(vma)) {
 683			pte = pte_offset_map(pmd, addr);
 684			pfn = pte_to_pagemap_entry(*pte);
 685			/* unmap before userspace copy */
 686			pte_unmap(pte);
 687		}
 688		err = add_to_pagemap(addr, pfn, pm);
 689		if (err)
 690			return err;
 691	}
 692
 693	cond_resched();
 694
 695	return err;
 696}
 697
 698#ifdef CONFIG_HUGETLB_PAGE
 699static u64 huge_pte_to_pagemap_entry(pte_t pte, int offset)
 700{
 701	u64 pme = 0;
 702	if (pte_present(pte))
 703		pme = PM_PFRAME(pte_pfn(pte) + offset)
 704			| PM_PSHIFT(PAGE_SHIFT) | PM_PRESENT;
 705	return pme;
 706}
 707
 708/* This function walks within one hugetlb entry in the single call */
 709static int pagemap_hugetlb_range(pte_t *pte, unsigned long hmask,
 710				 unsigned long addr, unsigned long end,
 711				 struct mm_walk *walk)
 712{
 713	struct pagemapread *pm = walk->private;
 714	int err = 0;
 715	u64 pfn;
 716
 717	for (; addr != end; addr += PAGE_SIZE) {
 718		int offset = (addr & ~hmask) >> PAGE_SHIFT;
 719		pfn = huge_pte_to_pagemap_entry(*pte, offset);
 720		err = add_to_pagemap(addr, pfn, pm);
 721		if (err)
 722			return err;
 723	}
 724
 725	cond_resched();
 726
 727	return err;
 728}
 729#endif /* HUGETLB_PAGE */
 730
 731/*
 732 * /proc/pid/pagemap - an array mapping virtual pages to pfns
 733 *
 734 * For each page in the address space, this file contains one 64-bit entry
 735 * consisting of the following:
 736 *
 737 * Bits 0-55  page frame number (PFN) if present
 738 * Bits 0-4   swap type if swapped
 739 * Bits 5-55  swap offset if swapped
 740 * Bits 55-60 page shift (page size = 1<<page shift)
 741 * Bit  61    reserved for future use
 742 * Bit  62    page swapped
 743 * Bit  63    page present
 744 *
 745 * If the page is not present but in swap, then the PFN contains an
 746 * encoding of the swap file number and the page's offset into the
 747 * swap. Unmapped pages return a null PFN. This allows determining
 748 * precisely which pages are mapped (or in swap) and comparing mapped
 749 * pages between processes.
 750 *
 751 * Efficient users of this interface will use /proc/pid/maps to
 752 * determine which areas of memory are actually mapped and llseek to
 753 * skip over unmapped regions.
 754 */
 755#define PAGEMAP_WALK_SIZE	(PMD_SIZE)
 756#define PAGEMAP_WALK_MASK	(PMD_MASK)
 757static ssize_t pagemap_read(struct file *file, char __user *buf,
 758			    size_t count, loff_t *ppos)
 759{
 760	struct task_struct *task = get_proc_task(file->f_path.dentry->d_inode);
 761	struct mm_struct *mm;
 762	struct pagemapread pm;
 763	int ret = -ESRCH;
 764	struct mm_walk pagemap_walk = {};
 765	unsigned long src;
 766	unsigned long svpfn;
 767	unsigned long start_vaddr;
 768	unsigned long end_vaddr;
 769	int copied = 0;
 770
 771	if (!task)
 772		goto out;
 773
 774	ret = -EINVAL;
 775	/* file position must be aligned */
 776	if ((*ppos % PM_ENTRY_BYTES) || (count % PM_ENTRY_BYTES))
 777		goto out_task;
 778
 779	ret = 0;
 780	if (!count)
 781		goto out_task;
 782
 783	pm.len = PM_ENTRY_BYTES * (PAGEMAP_WALK_SIZE >> PAGE_SHIFT);
 784	pm.buffer = kmalloc(pm.len, GFP_TEMPORARY);
 785	ret = -ENOMEM;
 786	if (!pm.buffer)
 787		goto out_task;
 788
 789	mm = mm_for_maps(task);
 790	ret = PTR_ERR(mm);
 791	if (!mm || IS_ERR(mm))
 792		goto out_free;
 793
 794	pagemap_walk.pmd_entry = pagemap_pte_range;
 795	pagemap_walk.pte_hole = pagemap_pte_hole;
 796#ifdef CONFIG_HUGETLB_PAGE
 797	pagemap_walk.hugetlb_entry = pagemap_hugetlb_range;
 798#endif
 799	pagemap_walk.mm = mm;
 800	pagemap_walk.private = &pm;
 801
 802	src = *ppos;
 803	svpfn = src / PM_ENTRY_BYTES;
 804	start_vaddr = svpfn << PAGE_SHIFT;
 805	end_vaddr = TASK_SIZE_OF(task);
 806
 807	/* watch out for wraparound */
 808	if (svpfn > TASK_SIZE_OF(task) >> PAGE_SHIFT)
 809		start_vaddr = end_vaddr;
 810
 811	/*
 812	 * The odds are that this will stop walking way
 813	 * before end_vaddr, because the length of the
 814	 * user buffer is tracked in "pm", and the walk
 815	 * will stop when we hit the end of the buffer.
 816	 */
 817	ret = 0;
 818	while (count && (start_vaddr < end_vaddr)) {
 819		int len;
 820		unsigned long end;
 821
 822		pm.pos = 0;
 823		end = (start_vaddr + PAGEMAP_WALK_SIZE) & PAGEMAP_WALK_MASK;
 824		/* overflow ? */
 825		if (end < start_vaddr || end > end_vaddr)
 826			end = end_vaddr;
 827		down_read(&mm->mmap_sem);
 828		ret = walk_page_range(start_vaddr, end, &pagemap_walk);
 829		up_read(&mm->mmap_sem);
 830		start_vaddr = end;
 831
 832		len = min(count, PM_ENTRY_BYTES * pm.pos);
 833		if (copy_to_user(buf, pm.buffer, len)) {
 834			ret = -EFAULT;
 835			goto out_mm;
 836		}
 837		copied += len;
 838		buf += len;
 839		count -= len;
 840	}
 841	*ppos += copied;
 842	if (!ret || ret == PM_END_OF_BUFFER)
 843		ret = copied;
 844
 845out_mm:
 846	mmput(mm);
 847out_free:
 848	kfree(pm.buffer);
 849out_task:
 850	put_task_struct(task);
 851out:
 852	return ret;
 853}
 854
 855const struct file_operations proc_pagemap_operations = {
 856	.llseek		= mem_lseek, /* borrow this */
 857	.read		= pagemap_read,
 858};
 859#endif /* CONFIG_PROC_PAGE_MONITOR */
 860
 861#ifdef CONFIG_NUMA
 862
 863struct numa_maps {
 864	struct vm_area_struct *vma;
 865	unsigned long pages;
 866	unsigned long anon;
 867	unsigned long active;
 868	unsigned long writeback;
 869	unsigned long mapcount_max;
 870	unsigned long dirty;
 871	unsigned long swapcache;
 872	unsigned long node[MAX_NUMNODES];
 873};
 874
 875struct numa_maps_private {
 876	struct proc_maps_private proc_maps;
 877	struct numa_maps md;
 878};
 879
 880static void gather_stats(struct page *page, struct numa_maps *md, int pte_dirty,
 881			unsigned long nr_pages)
 882{
 883	int count = page_mapcount(page);
 884
 885	md->pages += nr_pages;
 886	if (pte_dirty || PageDirty(page))
 887		md->dirty += nr_pages;
 888
 889	if (PageSwapCache(page))
 890		md->swapcache += nr_pages;
 891
 892	if (PageActive(page) || PageUnevictable(page))
 893		md->active += nr_pages;
 894
 895	if (PageWriteback(page))
 896		md->writeback += nr_pages;
 897
 898	if (PageAnon(page))
 899		md->anon += nr_pages;
 900
 901	if (count > md->mapcount_max)
 902		md->mapcount_max = count;
 903
 904	md->node[page_to_nid(page)] += nr_pages;
 905}
 906
 907static struct page *can_gather_numa_stats(pte_t pte, struct vm_area_struct *vma,
 908		unsigned long addr)
 909{
 910	struct page *page;
 911	int nid;
 912
 913	if (!pte_present(pte))
 914		return NULL;
 915
 916	page = vm_normal_page(vma, addr, pte);
 917	if (!page)
 918		return NULL;
 919
 920	if (PageReserved(page))
 921		return NULL;
 922
 923	nid = page_to_nid(page);
 924	if (!node_isset(nid, node_states[N_HIGH_MEMORY]))
 925		return NULL;
 926
 927	return page;
 928}
 929
 930static int gather_pte_stats(pmd_t *pmd, unsigned long addr,
 931		unsigned long end, struct mm_walk *walk)
 932{
 933	struct numa_maps *md;
 934	spinlock_t *ptl;
 935	pte_t *orig_pte;
 936	pte_t *pte;
 937
 938	md = walk->private;
 939	spin_lock(&walk->mm->page_table_lock);
 940	if (pmd_trans_huge(*pmd)) {
 941		if (pmd_trans_splitting(*pmd)) {
 942			spin_unlock(&walk->mm->page_table_lock);
 943			wait_split_huge_page(md->vma->anon_vma, pmd);
 944		} else {
 945			pte_t huge_pte = *(pte_t *)pmd;
 946			struct page *page;
 947
 948			page = can_gather_numa_stats(huge_pte, md->vma, addr);
 949			if (page)
 950				gather_stats(page, md, pte_dirty(huge_pte),
 951						HPAGE_PMD_SIZE/PAGE_SIZE);
 952			spin_unlock(&walk->mm->page_table_lock);
 953			return 0;
 954		}
 955	} else {
 956		spin_unlock(&walk->mm->page_table_lock);
 957	}
 958
 959	orig_pte = pte = pte_offset_map_lock(walk->mm, pmd, addr, &ptl);
 960	do {
 961		struct page *page = can_gather_numa_stats(*pte, md->vma, addr);
 962		if (!page)
 963			continue;
 964		gather_stats(page, md, pte_dirty(*pte), 1);
 965
 966	} while (pte++, addr += PAGE_SIZE, addr != end);
 967	pte_unmap_unlock(orig_pte, ptl);
 968	return 0;
 969}
 970#ifdef CONFIG_HUGETLB_PAGE
 971static int gather_hugetbl_stats(pte_t *pte, unsigned long hmask,
 972		unsigned long addr, unsigned long end, struct mm_walk *walk)
 973{
 974	struct numa_maps *md;
 975	struct page *page;
 976
 977	if (pte_none(*pte))
 978		return 0;
 979
 980	page = pte_page(*pte);
 981	if (!page)
 982		return 0;
 983
 984	md = walk->private;
 985	gather_stats(page, md, pte_dirty(*pte), 1);
 986	return 0;
 987}
 988
 989#else
 990static int gather_hugetbl_stats(pte_t *pte, unsigned long hmask,
 991		unsigned long addr, unsigned long end, struct mm_walk *walk)
 992{
 993	return 0;
 994}
 995#endif
 996
 997/*
 998 * Display pages allocated per node and memory policy via /proc.
 999 */
1000static int show_numa_map(struct seq_file *m, void *v)
1001{
1002	struct numa_maps_private *numa_priv = m->private;
1003	struct proc_maps_private *proc_priv = &numa_priv->proc_maps;
1004	struct vm_area_struct *vma = v;
1005	struct numa_maps *md = &numa_priv->md;
1006	struct file *file = vma->vm_file;
1007	struct mm_struct *mm = vma->vm_mm;
1008	struct mm_walk walk = {};
1009	struct mempolicy *pol;
1010	int n;
1011	char buffer[50];
1012
1013	if (!mm)
1014		return 0;
1015
1016	/* Ensure we start with an empty set of numa_maps statistics. */
1017	memset(md, 0, sizeof(*md));
1018
1019	md->vma = vma;
1020
1021	walk.hugetlb_entry = gather_hugetbl_stats;
1022	walk.pmd_entry = gather_pte_stats;
1023	walk.private = md;
1024	walk.mm = mm;
1025
1026	pol = get_vma_policy(proc_priv->task, vma, vma->vm_start);
1027	mpol_to_str(buffer, sizeof(buffer), pol, 0);
1028	mpol_cond_put(pol);
1029
1030	seq_printf(m, "%08lx %s", vma->vm_start, buffer);
1031
1032	if (file) {
1033		seq_printf(m, " file=");
1034		seq_path(m, &file->f_path, "\n\t= ");
1035	} else if (vma->vm_start <= mm->brk && vma->vm_end >= mm->start_brk) {
1036		seq_printf(m, " heap");
1037	} else if (vma->vm_start <= mm->start_stack &&
1038			vma->vm_end >= mm->start_stack) {
1039		seq_printf(m, " stack");
1040	}
1041
1042	if (is_vm_hugetlb_page(vma))
1043		seq_printf(m, " huge");
1044
1045	walk_page_range(vma->vm_start, vma->vm_end, &walk);
1046
1047	if (!md->pages)
1048		goto out;
1049
1050	if (md->anon)
1051		seq_printf(m, " anon=%lu", md->anon);
1052
1053	if (md->dirty)
1054		seq_printf(m, " dirty=%lu", md->dirty);
1055
1056	if (md->pages != md->anon && md->pages != md->dirty)
1057		seq_printf(m, " mapped=%lu", md->pages);
1058
1059	if (md->mapcount_max > 1)
1060		seq_printf(m, " mapmax=%lu", md->mapcount_max);
1061
1062	if (md->swapcache)
1063		seq_printf(m, " swapcache=%lu", md->swapcache);
1064
1065	if (md->active < md->pages && !is_vm_hugetlb_page(vma))
1066		seq_printf(m, " active=%lu", md->active);
1067
1068	if (md->writeback)
1069		seq_printf(m, " writeback=%lu", md->writeback);
1070
1071	for_each_node_state(n, N_HIGH_MEMORY)
1072		if (md->node[n])
1073			seq_printf(m, " N%d=%lu", n, md->node[n]);
1074out:
1075	seq_putc(m, '\n');
1076
1077	if (m->count < m->size)
1078		m->version = (vma != proc_priv->tail_vma) ? vma->vm_start : 0;
1079	return 0;
1080}
1081
1082static const struct seq_operations proc_pid_numa_maps_op = {
1083        .start  = m_start,
1084        .next   = m_next,
1085        .stop   = m_stop,
1086        .show   = show_numa_map,
1087};
1088
1089static int numa_maps_open(struct inode *inode, struct file *file)
1090{
1091	struct numa_maps_private *priv;
1092	int ret = -ENOMEM;
1093	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
1094	if (priv) {
1095		priv->proc_maps.pid = proc_pid(inode);
1096		ret = seq_open(file, &proc_pid_numa_maps_op);
1097		if (!ret) {
1098			struct seq_file *m = file->private_data;
1099			m->private = priv;
1100		} else {
1101			kfree(priv);
1102		}
1103	}
1104	return ret;
1105}
1106
1107const struct file_operations proc_numa_maps_operations = {
1108	.open		= numa_maps_open,
1109	.read		= seq_read,
1110	.llseek		= seq_lseek,
1111	.release	= seq_release_private,
1112};
1113#endif /* CONFIG_NUMA */