Adding upstream version 5.10.209.upstream/5.10.209upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1977 insertions, 0 deletions

diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c
new file mode 100644
index 000000000..39b103807
--- /dev/null
+++ b/fs/proc/task_mmu.c
@@ -0,0 +1,1977 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/pagewalk.h>
+#include <linux/vmacache.h>
+#include <linux/hugetlb.h>
+#include <linux/huge_mm.h>
+#include <linux/mount.h>
+#include <linux/seq_file.h>
+#include <linux/highmem.h>
+#include <linux/ptrace.h>
+#include <linux/slab.h>
+#include <linux/pagemap.h>
+#include <linux/mempolicy.h>
+#include <linux/rmap.h>
+#include <linux/swap.h>
+#include <linux/sched/mm.h>
+#include <linux/swapops.h>
+#include <linux/mmu_notifier.h>
+#include <linux/page_idle.h>
+#include <linux/shmem_fs.h>
+#include <linux/uaccess.h>
+#include <linux/pkeys.h>
+
+#include <asm/elf.h>
+#include <asm/tlb.h>
+#include <asm/tlbflush.h>
+#include "internal.h"
+
+#define SEQ_PUT_DEC(str, val) \
+		seq_put_decimal_ull_width(m, str, (val) << (PAGE_SHIFT-10), 8)
+void task_mem(struct seq_file *m, struct mm_struct *mm)
+{
+	unsigned long text, lib, swap, anon, file, shmem;
+	unsigned long hiwater_vm, total_vm, hiwater_rss, total_rss;
+
+	anon = get_mm_counter(mm, MM_ANONPAGES);
+	file = get_mm_counter(mm, MM_FILEPAGES);
+	shmem = get_mm_counter(mm, MM_SHMEMPAGES);
+
+	/*
+	 * Note: to minimize their overhead, mm maintains hiwater_vm and
+	 * hiwater_rss only when about to *lower* total_vm or rss.  Any
+	 * collector of these hiwater stats must therefore get total_vm
+	 * and rss too, which will usually be the higher.  Barriers? not
+	 * worth the effort, such snapshots can always be inconsistent.
+	 */
+	hiwater_vm = total_vm = mm->total_vm;
+	if (hiwater_vm < mm->hiwater_vm)
+		hiwater_vm = mm->hiwater_vm;
+	hiwater_rss = total_rss = anon + file + shmem;
+	if (hiwater_rss < mm->hiwater_rss)
+		hiwater_rss = mm->hiwater_rss;
+
+	/* split executable areas between text and lib */
+	text = PAGE_ALIGN(mm->end_code) - (mm->start_code & PAGE_MASK);
+	text = min(text, mm->exec_vm << PAGE_SHIFT);
+	lib = (mm->exec_vm << PAGE_SHIFT) - text;
+
+	swap = get_mm_counter(mm, MM_SWAPENTS);
+	SEQ_PUT_DEC("VmPeak:\t", hiwater_vm);
+	SEQ_PUT_DEC(" kB\nVmSize:\t", total_vm);
+	SEQ_PUT_DEC(" kB\nVmLck:\t", mm->locked_vm);
+	SEQ_PUT_DEC(" kB\nVmPin:\t", atomic64_read(&mm->pinned_vm));
+	SEQ_PUT_DEC(" kB\nVmHWM:\t", hiwater_rss);
+	SEQ_PUT_DEC(" kB\nVmRSS:\t", total_rss);
+	SEQ_PUT_DEC(" kB\nRssAnon:\t", anon);
+	SEQ_PUT_DEC(" kB\nRssFile:\t", file);
+	SEQ_PUT_DEC(" kB\nRssShmem:\t", shmem);
+	SEQ_PUT_DEC(" kB\nVmData:\t", mm->data_vm);
+	SEQ_PUT_DEC(" kB\nVmStk:\t", mm->stack_vm);
+	seq_put_decimal_ull_width(m,
+		    " kB\nVmExe:\t", text >> 10, 8);
+	seq_put_decimal_ull_width(m,
+		    " kB\nVmLib:\t", lib >> 10, 8);
+	seq_put_decimal_ull_width(m,
+		    " kB\nVmPTE:\t", mm_pgtables_bytes(mm) >> 10, 8);
+	SEQ_PUT_DEC(" kB\nVmSwap:\t", swap);
+	seq_puts(m, " kB\n");
+	hugetlb_report_usage(m, mm);
+}
+#undef SEQ_PUT_DEC
+
+unsigned long task_vsize(struct mm_struct *mm)
+{
+	return PAGE_SIZE * mm->total_vm;
+}
+
+unsigned long task_statm(struct mm_struct *mm,
+			 unsigned long *shared, unsigned long *text,
+			 unsigned long *data, unsigned long *resident)
+{
+	*shared = get_mm_counter(mm, MM_FILEPAGES) +
+			get_mm_counter(mm, MM_SHMEMPAGES);
+	*text = (PAGE_ALIGN(mm->end_code) - (mm->start_code & PAGE_MASK))
+								>> PAGE_SHIFT;
+	*data = mm->data_vm + mm->stack_vm;
+	*resident = *shared + get_mm_counter(mm, MM_ANONPAGES);
+	return mm->total_vm;
+}
+
+#ifdef CONFIG_NUMA
+/*
+ * Save get_task_policy() for show_numa_map().
+ */
+static void hold_task_mempolicy(struct proc_maps_private *priv)
+{
+	struct task_struct *task = priv->task;
+
+	task_lock(task);
+	priv->task_mempolicy = get_task_policy(task);
+	mpol_get(priv->task_mempolicy);
+	task_unlock(task);
+}
+static void release_task_mempolicy(struct proc_maps_private *priv)
+{
+	mpol_put(priv->task_mempolicy);
+}
+#else
+static void hold_task_mempolicy(struct proc_maps_private *priv)
+{
+}
+static void release_task_mempolicy(struct proc_maps_private *priv)
+{
+}
+#endif
+
+static void *m_start(struct seq_file *m, loff_t *ppos)
+{
+	struct proc_maps_private *priv = m->private;
+	unsigned long last_addr = *ppos;
+	struct mm_struct *mm;
+	struct vm_area_struct *vma;
+
+	/* See m_next(). Zero at the start or after lseek. */
+	if (last_addr == -1UL)
+		return NULL;
+
+	priv->task = get_proc_task(priv->inode);
+	if (!priv->task)
+		return ERR_PTR(-ESRCH);
+
+	mm = priv->mm;
+	if (!mm || !mmget_not_zero(mm)) {
+		put_task_struct(priv->task);
+		priv->task = NULL;
+		return NULL;
+	}
+
+	if (mmap_read_lock_killable(mm)) {
+		mmput(mm);
+		put_task_struct(priv->task);
+		priv->task = NULL;
+		return ERR_PTR(-EINTR);
+	}
+
+	hold_task_mempolicy(priv);
+	priv->tail_vma = get_gate_vma(mm);
+
+	vma = find_vma(mm, last_addr);
+	if (vma)
+		return vma;
+
+	return priv->tail_vma;
+}
+
+static void *m_next(struct seq_file *m, void *v, loff_t *ppos)
+{
+	struct proc_maps_private *priv = m->private;
+	struct vm_area_struct *next, *vma = v;
+
+	if (vma == priv->tail_vma)
+		next = NULL;
+	else if (vma->vm_next)
+		next = vma->vm_next;
+	else
+		next = priv->tail_vma;
+
+	*ppos = next ? next->vm_start : -1UL;
+
+	return next;
+}
+
+static void m_stop(struct seq_file *m, void *v)
+{
+	struct proc_maps_private *priv = m->private;
+	struct mm_struct *mm = priv->mm;
+
+	if (!priv->task)
+		return;
+
+	release_task_mempolicy(priv);
+	mmap_read_unlock(mm);
+	mmput(mm);
+	put_task_struct(priv->task);
+	priv->task = NULL;
+}
+
+static int proc_maps_open(struct inode *inode, struct file *file,
+			const struct seq_operations *ops, int psize)
+{
+	struct proc_maps_private *priv = __seq_open_private(file, ops, psize);
+
+	if (!priv)
+		return -ENOMEM;
+
+	priv->inode = inode;
+	priv->mm = proc_mem_open(inode, PTRACE_MODE_READ);
+	if (IS_ERR(priv->mm)) {
+		int err = PTR_ERR(priv->mm);
+
+		seq_release_private(inode, file);
+		return err;
+	}
+
+	return 0;
+}
+
+static int proc_map_release(struct inode *inode, struct file *file)
+{
+	struct seq_file *seq = file->private_data;
+	struct proc_maps_private *priv = seq->private;
+
+	if (priv->mm)
+		mmdrop(priv->mm);
+
+	return seq_release_private(inode, file);
+}
+
+static int do_maps_open(struct inode *inode, struct file *file,
+			const struct seq_operations *ops)
+{
+	return proc_maps_open(inode, file, ops,
+				sizeof(struct proc_maps_private));
+}
+
+/*
+ * Indicate if the VMA is a stack for the given task; for
+ * /proc/PID/maps that is the stack of the main task.
+ */
+static int is_stack(struct vm_area_struct *vma)
+{
+	/*
+	 * We make no effort to guess what a given thread considers to be
+	 * its "stack".  It's not even well-defined for programs written
+	 * languages like Go.
+	 */
+	return vma->vm_start <= vma->vm_mm->start_stack &&
+		vma->vm_end >= vma->vm_mm->start_stack;
+}
+
+static void show_vma_header_prefix(struct seq_file *m,
+				   unsigned long start, unsigned long end,
+				   vm_flags_t flags, unsigned long long pgoff,
+				   dev_t dev, unsigned long ino)
+{
+	seq_setwidth(m, 25 + sizeof(void *) * 6 - 1);
+	seq_put_hex_ll(m, NULL, start, 8);
+	seq_put_hex_ll(m, "-", end, 8);
+	seq_putc(m, ' ');
+	seq_putc(m, flags & VM_READ ? 'r' : '-');
+	seq_putc(m, flags & VM_WRITE ? 'w' : '-');
+	seq_putc(m, flags & VM_EXEC ? 'x' : '-');
+	seq_putc(m, flags & VM_MAYSHARE ? 's' : 'p');
+	seq_put_hex_ll(m, " ", pgoff, 8);
+	seq_put_hex_ll(m, " ", MAJOR(dev), 2);
+	seq_put_hex_ll(m, ":", MINOR(dev), 2);
+	seq_put_decimal_ull(m, " ", ino);
+	seq_putc(m, ' ');
+}
+
+static void
+show_map_vma(struct seq_file *m, struct vm_area_struct *vma)
+{
+	struct mm_struct *mm = vma->vm_mm;
+	struct file *file = vma->vm_file;
+	vm_flags_t flags = vma->vm_flags;
+	unsigned long ino = 0;
+	unsigned long long pgoff = 0;
+	unsigned long start, end;
+	dev_t dev = 0;
+	const char *name = NULL;
+
+	if (file) {
+		struct inode *inode = file_inode(vma->vm_file);
+		dev = inode->i_sb->s_dev;
+		ino = inode->i_ino;
+		pgoff = ((loff_t)vma->vm_pgoff) << PAGE_SHIFT;
+	}
+
+	start = vma->vm_start;
+	end = vma->vm_end;
+	show_vma_header_prefix(m, start, end, flags, pgoff, dev, ino);
+
+	/*
+	 * Print the dentry name for named mappings, and a
+	 * special [heap] marker for the heap:
+	 */
+	if (file) {
+		seq_pad(m, ' ');
+		seq_file_path(m, file, "\n");
+		goto done;
+	}
+
+	if (vma->vm_ops && vma->vm_ops->name) {
+		name = vma->vm_ops->name(vma);
+		if (name)
+			goto done;
+	}
+
+	name = arch_vma_name(vma);
+	if (!name) {
+		if (!mm) {
+			name = "[vdso]";
+			goto done;
+		}
+
+		if (vma->vm_start <= mm->brk &&
+		    vma->vm_end >= mm->start_brk) {
+			name = "[heap]";
+			goto done;
+		}
+
+		if (is_stack(vma))
+			name = "[stack]";
+	}
+
+done:
+	if (name) {
+		seq_pad(m, ' ');
+		seq_puts(m, name);
+	}
+	seq_putc(m, '\n');
+}
+
+static int show_map(struct seq_file *m, void *v)
+{
+	show_map_vma(m, v);
+	return 0;
+}
+
+static const struct seq_operations proc_pid_maps_op = {
+	.start	= m_start,
+	.next	= m_next,
+	.stop	= m_stop,
+	.show	= show_map
+};
+
+static int pid_maps_open(struct inode *inode, struct file *file)
+{
+	return do_maps_open(inode, file, &proc_pid_maps_op);
+}
+
+const struct file_operations proc_pid_maps_operations = {
+	.open		= pid_maps_open,
+	.read		= seq_read,
+	.llseek		= seq_lseek,
+	.release	= proc_map_release,
+};
+
+/*
+ * Proportional Set Size(PSS): my share of RSS.
+ *
+ * PSS of a process is the count of pages it has in memory, where each
+ * page is divided by the number of processes sharing it.  So if a
+ * process has 1000 pages all to itself, and 1000 shared with one other
+ * process, its PSS will be 1500.
+ *
+ * To keep (accumulated) division errors low, we adopt a 64bit
+ * fixed-point pss counter to minimize division errors. So (pss >>
+ * PSS_SHIFT) would be the real byte count.
+ *
+ * A shift of 12 before division means (assuming 4K page size):
+ * 	- 1M 3-user-pages add up to 8KB errors;
+ * 	- supports mapcount up to 2^24, or 16M;
+ * 	- supports PSS up to 2^52 bytes, or 4PB.
+ */
+#define PSS_SHIFT 12
+
+#ifdef CONFIG_PROC_PAGE_MONITOR
+struct mem_size_stats {
+	unsigned long resident;
+	unsigned long shared_clean;
+	unsigned long shared_dirty;
+	unsigned long private_clean;
+	unsigned long private_dirty;
+	unsigned long referenced;
+	unsigned long anonymous;
+	unsigned long lazyfree;
+	unsigned long anonymous_thp;
+	unsigned long shmem_thp;
+	unsigned long file_thp;
+	unsigned long swap;
+	unsigned long shared_hugetlb;
+	unsigned long private_hugetlb;
+	u64 pss;
+	u64 pss_anon;
+	u64 pss_file;
+	u64 pss_shmem;
+	u64 pss_locked;
+	u64 swap_pss;
+	bool check_shmem_swap;
+};
+
+static void smaps_page_accumulate(struct mem_size_stats *mss,
+		struct page *page, unsigned long size, unsigned long pss,
+		bool dirty, bool locked, bool private)
+{
+	mss->pss += pss;
+
+	if (PageAnon(page))
+		mss->pss_anon += pss;
+	else if (PageSwapBacked(page))
+		mss->pss_shmem += pss;
+	else
+		mss->pss_file += pss;
+
+	if (locked)
+		mss->pss_locked += pss;
+
+	if (dirty || PageDirty(page)) {
+		if (private)
+			mss->private_dirty += size;
+		else
+			mss->shared_dirty += size;
+	} else {
+		if (private)
+			mss->private_clean += size;
+		else
+			mss->shared_clean += size;
+	}
+}
+
+static void smaps_account(struct mem_size_stats *mss, struct page *page,
+		bool compound, bool young, bool dirty, bool locked,
+		bool migration)
+{
+	int i, nr = compound ? compound_nr(page) : 1;
+	unsigned long size = nr * PAGE_SIZE;
+
+	/*
+	 * First accumulate quantities that depend only on |size| and the type
+	 * of the compound page.
+	 */
+	if (PageAnon(page)) {
+		mss->anonymous += size;
+		if (!PageSwapBacked(page) && !dirty && !PageDirty(page))
+			mss->lazyfree += size;
+	}
+
+	mss->resident += size;
+	/* Accumulate the size in pages that have been accessed. */
+	if (young || page_is_young(page) || PageReferenced(page))
+		mss->referenced += size;
+
+	/*
+	 * Then accumulate quantities that may depend on sharing, or that may
+	 * differ page-by-page.
+	 *
+	 * page_count(page) == 1 guarantees the page is mapped exactly once.
+	 * If any subpage of the compound page mapped with PTE it would elevate
+	 * page_count().
+	 *
+	 * The page_mapcount() is called to get a snapshot of the mapcount.
+	 * Without holding the page lock this snapshot can be slightly wrong as
+	 * we cannot always read the mapcount atomically.  It is not safe to
+	 * call page_mapcount() even with PTL held if the page is not mapped,
+	 * especially for migration entries.  Treat regular migration entries
+	 * as mapcount == 1.
+	 */
+	if ((page_count(page) == 1) || migration) {
+		smaps_page_accumulate(mss, page, size, size << PSS_SHIFT, dirty,
+			locked, true);
+		return;
+	}
+	for (i = 0; i < nr; i++, page++) {
+		int mapcount = page_mapcount(page);
+		unsigned long pss = PAGE_SIZE << PSS_SHIFT;
+		if (mapcount >= 2)
+			pss /= mapcount;
+		smaps_page_accumulate(mss, page, PAGE_SIZE, pss, dirty, locked,
+				      mapcount < 2);
+	}
+}
+
+#ifdef CONFIG_SHMEM
+static int smaps_pte_hole(unsigned long addr, unsigned long end,
+			  __always_unused int depth, struct mm_walk *walk)
+{
+	struct mem_size_stats *mss = walk->private;
+
+	mss->swap += shmem_partial_swap_usage(
+			walk->vma->vm_file->f_mapping, addr, end);
+
+	return 0;
+}
+#else
+#define smaps_pte_hole		NULL
+#endif /* CONFIG_SHMEM */
+
+static void smaps_pte_entry(pte_t *pte, unsigned long addr,
+		struct mm_walk *walk)
+{
+	struct mem_size_stats *mss = walk->private;
+	struct vm_area_struct *vma = walk->vma;
+	bool locked = !!(vma->vm_flags & VM_LOCKED);
+	struct page *page = NULL;
+	bool migration = false, young = false, dirty = false;
+
+	if (pte_present(*pte)) {
+		page = vm_normal_page(vma, addr, *pte);
+		young = pte_young(*pte);
+		dirty = pte_dirty(*pte);
+	} else if (is_swap_pte(*pte)) {
+		swp_entry_t swpent = pte_to_swp_entry(*pte);
+
+		if (!non_swap_entry(swpent)) {
+			int mapcount;
+
+			mss->swap += PAGE_SIZE;
+			mapcount = swp_swapcount(swpent);
+			if (mapcount >= 2) {
+				u64 pss_delta = (u64)PAGE_SIZE << PSS_SHIFT;
+
+				do_div(pss_delta, mapcount);
+				mss->swap_pss += pss_delta;
+			} else {
+				mss->swap_pss += (u64)PAGE_SIZE << PSS_SHIFT;
+			}
+		} else if (is_migration_entry(swpent)) {
+			migration = true;
+			page = migration_entry_to_page(swpent);
+		} else if (is_device_private_entry(swpent))
+			page = device_private_entry_to_page(swpent);
+	} else if (unlikely(IS_ENABLED(CONFIG_SHMEM) && mss->check_shmem_swap
+							&& pte_none(*pte))) {
+		page = xa_load(&vma->vm_file->f_mapping->i_pages,
+						linear_page_index(vma, addr));
+		if (xa_is_value(page))
+			mss->swap += PAGE_SIZE;
+		return;
+	}
+
+	if (!page)
+		return;
+
+	smaps_account(mss, page, false, young, dirty, locked, migration);
+}
+
+#ifdef CONFIG_TRANSPARENT_HUGEPAGE
+static void smaps_pmd_entry(pmd_t *pmd, unsigned long addr,
+		struct mm_walk *walk)
+{
+	struct mem_size_stats *mss = walk->private;
+	struct vm_area_struct *vma = walk->vma;
+	bool locked = !!(vma->vm_flags & VM_LOCKED);
+	struct page *page = NULL;
+	bool migration = false;
+
+	if (pmd_present(*pmd)) {
+		/* FOLL_DUMP will return -EFAULT on huge zero page */
+		page = follow_trans_huge_pmd(vma, addr, pmd, FOLL_DUMP);
+	} else if (unlikely(thp_migration_supported() && is_swap_pmd(*pmd))) {
+		swp_entry_t entry = pmd_to_swp_entry(*pmd);
+
+		if (is_migration_entry(entry)) {
+			migration = true;
+			page = migration_entry_to_page(entry);
+		}
+	}
+	if (IS_ERR_OR_NULL(page))
+		return;
+	if (PageAnon(page))
+		mss->anonymous_thp += HPAGE_PMD_SIZE;
+	else if (PageSwapBacked(page))
+		mss->shmem_thp += HPAGE_PMD_SIZE;
+	else if (is_zone_device_page(page))
+		/* pass */;
+	else
+		mss->file_thp += HPAGE_PMD_SIZE;
+
+	smaps_account(mss, page, true, pmd_young(*pmd), pmd_dirty(*pmd),
+		      locked, migration);
+}
+#else
+static void smaps_pmd_entry(pmd_t *pmd, unsigned long addr,
+		struct mm_walk *walk)
+{
+}
+#endif
+
+static int smaps_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end,
+			   struct mm_walk *walk)
+{
+	struct vm_area_struct *vma = walk->vma;
+	pte_t *pte;
+	spinlock_t *ptl;
+
+	ptl = pmd_trans_huge_lock(pmd, vma);
+	if (ptl) {
+		smaps_pmd_entry(pmd, addr, walk);
+		spin_unlock(ptl);
+		goto out;
+	}
+
+	if (pmd_trans_unstable(pmd))
+		goto out;
+	/*
+	 * The mmap_lock held all the way back in m_start() is what
+	 * keeps khugepaged out of here and from collapsing things
+	 * in here.
+	 */
+	pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl);
+	for (; addr != end; pte++, addr += PAGE_SIZE)
+		smaps_pte_entry(pte, addr, walk);
+	pte_unmap_unlock(pte - 1, ptl);
+out:
+	cond_resched();
+	return 0;
+}
+
+static void show_smap_vma_flags(struct seq_file *m, struct vm_area_struct *vma)
+{
+	/*
+	 * Don't forget to update Documentation/ on changes.
+	 */
+	static const char mnemonics[BITS_PER_LONG][2] = {
+		/*
+		 * In case if we meet a flag we don't know about.
+		 */
+		[0 ... (BITS_PER_LONG-1)] = "??",
+
+		[ilog2(VM_READ)]	= "rd",
+		[ilog2(VM_WRITE)]	= "wr",
+		[ilog2(VM_EXEC)]	= "ex",
+		[ilog2(VM_SHARED)]	= "sh",
+		[ilog2(VM_MAYREAD)]	= "mr",
+		[ilog2(VM_MAYWRITE)]	= "mw",
+		[ilog2(VM_MAYEXEC)]	= "me",
+		[ilog2(VM_MAYSHARE)]	= "ms",
+		[ilog2(VM_GROWSDOWN)]	= "gd",
+		[ilog2(VM_PFNMAP)]	= "pf",
+		[ilog2(VM_DENYWRITE)]	= "dw",
+		[ilog2(VM_LOCKED)]	= "lo",
+		[ilog2(VM_IO)]		= "io",
+		[ilog2(VM_SEQ_READ)]	= "sr",
+		[ilog2(VM_RAND_READ)]	= "rr",
+		[ilog2(VM_DONTCOPY)]	= "dc",
+		[ilog2(VM_DONTEXPAND)]	= "de",
+		[ilog2(VM_ACCOUNT)]	= "ac",
+		[ilog2(VM_NORESERVE)]	= "nr",
+		[ilog2(VM_HUGETLB)]	= "ht",
+		[ilog2(VM_SYNC)]	= "sf",
+		[ilog2(VM_ARCH_1)]	= "ar",
+		[ilog2(VM_WIPEONFORK)]	= "wf",
+		[ilog2(VM_DONTDUMP)]	= "dd",
+#ifdef CONFIG_ARM64_BTI
+		[ilog2(VM_ARM64_BTI)]	= "bt",
+#endif
+#ifdef CONFIG_MEM_SOFT_DIRTY
+		[ilog2(VM_SOFTDIRTY)]	= "sd",
+#endif
+		[ilog2(VM_MIXEDMAP)]	= "mm",
+		[ilog2(VM_HUGEPAGE)]	= "hg",
+		[ilog2(VM_NOHUGEPAGE)]	= "nh",
+		[ilog2(VM_MERGEABLE)]	= "mg",
+		[ilog2(VM_UFFD_MISSING)]= "um",
+		[ilog2(VM_UFFD_WP)]	= "uw",
+#ifdef CONFIG_ARM64_MTE
+		[ilog2(VM_MTE)]		= "mt",
+		[ilog2(VM_MTE_ALLOWED)]	= "",
+#endif
+#ifdef CONFIG_ARCH_HAS_PKEYS
+		/* These come out via ProtectionKey: */
+		[ilog2(VM_PKEY_BIT0)]	= "",
+		[ilog2(VM_PKEY_BIT1)]	= "",
+		[ilog2(VM_PKEY_BIT2)]	= "",
+		[ilog2(VM_PKEY_BIT3)]	= "",
+#if VM_PKEY_BIT4
+		[ilog2(VM_PKEY_BIT4)]	= "",
+#endif
+#endif /* CONFIG_ARCH_HAS_PKEYS */
+	};
+	size_t i;
+
+	seq_puts(m, "VmFlags: ");
+	for (i = 0; i < BITS_PER_LONG; i++) {
+		if (!mnemonics[i][0])
+			continue;
+		if (vma->vm_flags & (1UL << i)) {
+			seq_putc(m, mnemonics[i][0]);
+			seq_putc(m, mnemonics[i][1]);
+			seq_putc(m, ' ');
+		}
+	}
+	seq_putc(m, '\n');
+}
+
+#ifdef CONFIG_HUGETLB_PAGE
+static int smaps_hugetlb_range(pte_t *pte, unsigned long hmask,
+				 unsigned long addr, unsigned long end,
+				 struct mm_walk *walk)
+{
+	struct mem_size_stats *mss = walk->private;
+	struct vm_area_struct *vma = walk->vma;
+	struct page *page = NULL;
+
+	if (pte_present(*pte)) {
+		page = vm_normal_page(vma, addr, *pte);
+	} else if (is_swap_pte(*pte)) {
+		swp_entry_t swpent = pte_to_swp_entry(*pte);
+
+		if (is_migration_entry(swpent))
+			page = migration_entry_to_page(swpent);
+		else if (is_device_private_entry(swpent))
+			page = device_private_entry_to_page(swpent);
+	}
+	if (page) {
+		if (page_mapcount(page) >= 2 || hugetlb_pmd_shared(pte))
+			mss->shared_hugetlb += huge_page_size(hstate_vma(vma));
+		else
+			mss->private_hugetlb += huge_page_size(hstate_vma(vma));
+	}
+	return 0;
+}
+#else
+#define smaps_hugetlb_range	NULL
+#endif /* HUGETLB_PAGE */
+
+static const struct mm_walk_ops smaps_walk_ops = {
+	.pmd_entry		= smaps_pte_range,
+	.hugetlb_entry		= smaps_hugetlb_range,
+};
+
+static const struct mm_walk_ops smaps_shmem_walk_ops = {
+	.pmd_entry		= smaps_pte_range,
+	.hugetlb_entry		= smaps_hugetlb_range,
+	.pte_hole		= smaps_pte_hole,
+};
+
+/*
+ * Gather mem stats from @vma with the indicated beginning
+ * address @start, and keep them in @mss.
+ *
+ * Use vm_start of @vma as the beginning address if @start is 0.
+ */
+static void smap_gather_stats(struct vm_area_struct *vma,
+		struct mem_size_stats *mss, unsigned long start)
+{
+	const struct mm_walk_ops *ops = &smaps_walk_ops;
+
+	/* Invalid start */
+	if (start >= vma->vm_end)
+		return;
+
+#ifdef CONFIG_SHMEM
+	/* In case of smaps_rollup, reset the value from previous vma */
+	mss->check_shmem_swap = false;
+	if (vma->vm_file && shmem_mapping(vma->vm_file->f_mapping)) {
+		/*
+		 * For shared or readonly shmem mappings we know that all
+		 * swapped out pages belong to the shmem object, and we can
+		 * obtain the swap value much more efficiently. For private
+		 * writable mappings, we might have COW pages that are
+		 * not affected by the parent swapped out pages of the shmem
+		 * object, so we have to distinguish them during the page walk.
+		 * Unless we know that the shmem object (or the part mapped by
+		 * our VMA) has no swapped out pages at all.
+		 */
+		unsigned long shmem_swapped = shmem_swap_usage(vma);
+
+		if (!start && (!shmem_swapped || (vma->vm_flags & VM_SHARED) ||
+					!(vma->vm_flags & VM_WRITE))) {
+			mss->swap += shmem_swapped;
+		} else {
+			mss->check_shmem_swap = true;
+			ops = &smaps_shmem_walk_ops;
+		}
+	}
+#endif
+	/* mmap_lock is held in m_start */
+	if (!start)
+		walk_page_vma(vma, ops, mss);
+	else
+		walk_page_range(vma->vm_mm, start, vma->vm_end, ops, mss);
+}
+
+#define SEQ_PUT_DEC(str, val) \
+		seq_put_decimal_ull_width(m, str, (val) >> 10, 8)
+
+/* Show the contents common for smaps and smaps_rollup */
+static void __show_smap(struct seq_file *m, const struct mem_size_stats *mss,
+	bool rollup_mode)
+{
+	SEQ_PUT_DEC("Rss:            ", mss->resident);
+	SEQ_PUT_DEC(" kB\nPss:            ", mss->pss >> PSS_SHIFT);
+	if (rollup_mode) {
+		/*
+		 * These are meaningful only for smaps_rollup, otherwise two of
+		 * them are zero, and the other one is the same as Pss.
+		 */
+		SEQ_PUT_DEC(" kB\nPss_Anon:       ",
+			mss->pss_anon >> PSS_SHIFT);
+		SEQ_PUT_DEC(" kB\nPss_File:       ",
+			mss->pss_file >> PSS_SHIFT);
+		SEQ_PUT_DEC(" kB\nPss_Shmem:      ",
+			mss->pss_shmem >> PSS_SHIFT);
+	}
+	SEQ_PUT_DEC(" kB\nShared_Clean:   ", mss->shared_clean);
+	SEQ_PUT_DEC(" kB\nShared_Dirty:   ", mss->shared_dirty);
+	SEQ_PUT_DEC(" kB\nPrivate_Clean:  ", mss->private_clean);
+	SEQ_PUT_DEC(" kB\nPrivate_Dirty:  ", mss->private_dirty);
+	SEQ_PUT_DEC(" kB\nReferenced:     ", mss->referenced);
+	SEQ_PUT_DEC(" kB\nAnonymous:      ", mss->anonymous);
+	SEQ_PUT_DEC(" kB\nLazyFree:       ", mss->lazyfree);
+	SEQ_PUT_DEC(" kB\nAnonHugePages:  ", mss->anonymous_thp);
+	SEQ_PUT_DEC(" kB\nShmemPmdMapped: ", mss->shmem_thp);
+	SEQ_PUT_DEC(" kB\nFilePmdMapped:  ", mss->file_thp);
+	SEQ_PUT_DEC(" kB\nShared_Hugetlb: ", mss->shared_hugetlb);
+	seq_put_decimal_ull_width(m, " kB\nPrivate_Hugetlb: ",
+				  mss->private_hugetlb >> 10, 7);
+	SEQ_PUT_DEC(" kB\nSwap:           ", mss->swap);
+	SEQ_PUT_DEC(" kB\nSwapPss:        ",
+					mss->swap_pss >> PSS_SHIFT);
+	SEQ_PUT_DEC(" kB\nLocked:         ",
+					mss->pss_locked >> PSS_SHIFT);
+	seq_puts(m, " kB\n");
+}
+
+static int show_smap(struct seq_file *m, void *v)
+{
+	struct vm_area_struct *vma = v;
+	struct mem_size_stats mss;
+
+	memset(&mss, 0, sizeof(mss));
+
+	smap_gather_stats(vma, &mss, 0);
+
+	show_map_vma(m, vma);
+
+	SEQ_PUT_DEC("Size:           ", vma->vm_end - vma->vm_start);
+	SEQ_PUT_DEC(" kB\nKernelPageSize: ", vma_kernel_pagesize(vma));
+	SEQ_PUT_DEC(" kB\nMMUPageSize:    ", vma_mmu_pagesize(vma));
+	seq_puts(m, " kB\n");
+
+	__show_smap(m, &mss, false);
+
+	seq_printf(m, "THPeligible:    %d\n",
+		   transparent_hugepage_active(vma));
+
+	if (arch_pkeys_enabled())
+		seq_printf(m, "ProtectionKey:  %8u\n", vma_pkey(vma));
+	show_smap_vma_flags(m, vma);
+
+	return 0;
+}
+
+static int show_smaps_rollup(struct seq_file *m, void *v)
+{
+	struct proc_maps_private *priv = m->private;
+	struct mem_size_stats mss;
+	struct mm_struct *mm;
+	struct vm_area_struct *vma;
+	unsigned long last_vma_end = 0;
+	int ret = 0;
+
+	priv->task = get_proc_task(priv->inode);
+	if (!priv->task)
+		return -ESRCH;
+
+	mm = priv->mm;
+	if (!mm || !mmget_not_zero(mm)) {
+		ret = -ESRCH;
+		goto out_put_task;
+	}
+
+	memset(&mss, 0, sizeof(mss));
+
+	ret = mmap_read_lock_killable(mm);
+	if (ret)
+		goto out_put_mm;
+
+	hold_task_mempolicy(priv);
+
+	for (vma = priv->mm->mmap; vma;) {
+		smap_gather_stats(vma, &mss, 0);
+		last_vma_end = vma->vm_end;
+
+		/*
+		 * Release mmap_lock temporarily if someone wants to
+		 * access it for write request.
+		 */
+		if (mmap_lock_is_contended(mm)) {
+			mmap_read_unlock(mm);
+			ret = mmap_read_lock_killable(mm);
+			if (ret) {
+				release_task_mempolicy(priv);
+				goto out_put_mm;
+			}
+
+			/*
+			 * After dropping the lock, there are four cases to
+			 * consider. See the following example for explanation.
+			 *
+			 *   +------+------+-----------+
+			 *   | VMA1 | VMA2 | VMA3      |
+			 *   +------+------+-----------+
+			 *   |      |      |           |
+			 *  4k     8k     16k         400k
+			 *
+			 * Suppose we drop the lock after reading VMA2 due to
+			 * contention, then we get:
+			 *
+			 *	last_vma_end = 16k
+			 *
+			 * 1) VMA2 is freed, but VMA3 exists:
+			 *
+			 *    find_vma(mm, 16k - 1) will return VMA3.
+			 *    In this case, just continue from VMA3.
+			 *
+			 * 2) VMA2 still exists:
+			 *
+			 *    find_vma(mm, 16k - 1) will return VMA2.
+			 *    Iterate the loop like the original one.
+			 *
+			 * 3) No more VMAs can be found:
+			 *
+			 *    find_vma(mm, 16k - 1) will return NULL.
+			 *    No more things to do, just break.
+			 *
+			 * 4) (last_vma_end - 1) is the middle of a vma (VMA'):
+			 *
+			 *    find_vma(mm, 16k - 1) will return VMA' whose range
+			 *    contains last_vma_end.
+			 *    Iterate VMA' from last_vma_end.
+			 */
+			vma = find_vma(mm, last_vma_end - 1);
+			/* Case 3 above */
+			if (!vma)
+				break;
+
+			/* Case 1 above */
+			if (vma->vm_start >= last_vma_end)
+				continue;
+
+			/* Case 4 above */
+			if (vma->vm_end > last_vma_end)
+				smap_gather_stats(vma, &mss, last_vma_end);
+		}
+		/* Case 2 above */
+		vma = vma->vm_next;
+	}
+
+	show_vma_header_prefix(m, priv->mm->mmap ? priv->mm->mmap->vm_start : 0,
+			       last_vma_end, 0, 0, 0, 0);
+	seq_pad(m, ' ');
+	seq_puts(m, "[rollup]\n");
+
+	__show_smap(m, &mss, true);
+
+	release_task_mempolicy(priv);
+	mmap_read_unlock(mm);
+
+out_put_mm:
+	mmput(mm);
+out_put_task:
+	put_task_struct(priv->task);
+	priv->task = NULL;
+
+	return ret;
+}
+#undef SEQ_PUT_DEC
+
+static const struct seq_operations proc_pid_smaps_op = {
+	.start	= m_start,
+	.next	= m_next,
+	.stop	= m_stop,
+	.show	= show_smap
+};
+
+static int pid_smaps_open(struct inode *inode, struct file *file)
+{
+	return do_maps_open(inode, file, &proc_pid_smaps_op);
+}
+
+static int smaps_rollup_open(struct inode *inode, struct file *file)
+{
+	int ret;
+	struct proc_maps_private *priv;
+
+	priv = kzalloc(sizeof(*priv), GFP_KERNEL_ACCOUNT);
+	if (!priv)
+		return -ENOMEM;
+
+	ret = single_open(file, show_smaps_rollup, priv);
+	if (ret)
+		goto out_free;
+
+	priv->inode = inode;
+	priv->mm = proc_mem_open(inode, PTRACE_MODE_READ);
+	if (IS_ERR(priv->mm)) {
+		ret = PTR_ERR(priv->mm);
+
+		single_release(inode, file);
+		goto out_free;
+	}
+
+	return 0;
+
+out_free:
+	kfree(priv);
+	return ret;
+}
+
+static int smaps_rollup_release(struct inode *inode, struct file *file)
+{
+	struct seq_file *seq = file->private_data;
+	struct proc_maps_private *priv = seq->private;
+
+	if (priv->mm)
+		mmdrop(priv->mm);
+
+	kfree(priv);
+	return single_release(inode, file);
+}
+
+const struct file_operations proc_pid_smaps_operations = {
+	.open		= pid_smaps_open,
+	.read		= seq_read,
+	.llseek		= seq_lseek,
+	.release	= proc_map_release,
+};
+
+const struct file_operations proc_pid_smaps_rollup_operations = {
+	.open		= smaps_rollup_open,
+	.read		= seq_read,
+	.llseek		= seq_lseek,
+	.release	= smaps_rollup_release,
+};
+
+enum clear_refs_types {
+	CLEAR_REFS_ALL = 1,
+	CLEAR_REFS_ANON,
+	CLEAR_REFS_MAPPED,
+	CLEAR_REFS_SOFT_DIRTY,
+	CLEAR_REFS_MM_HIWATER_RSS,
+	CLEAR_REFS_LAST,
+};
+
+struct clear_refs_private {
+	enum clear_refs_types type;
+};
+
+#ifdef CONFIG_MEM_SOFT_DIRTY
+
+#define is_cow_mapping(flags) (((flags) & (VM_SHARED | VM_MAYWRITE)) == VM_MAYWRITE)
+
+static inline bool pte_is_pinned(struct vm_area_struct *vma, unsigned long addr, pte_t pte)
+{
+	struct page *page;
+
+	if (!pte_write(pte))
+		return false;
+	if (!is_cow_mapping(vma->vm_flags))
+		return false;
+	if (likely(!atomic_read(&vma->vm_mm->has_pinned)))
+		return false;
+	page = vm_normal_page(vma, addr, pte);
+	if (!page)
+		return false;
+	return page_maybe_dma_pinned(page);
+}
+
+static inline void clear_soft_dirty(struct vm_area_struct *vma,
+		unsigned long addr, pte_t *pte)
+{
+	/*
+	 * The soft-dirty tracker uses #PF-s to catch writes
+	 * to pages, so write-protect the pte as well. See the
+	 * Documentation/admin-guide/mm/soft-dirty.rst for full description
+	 * of how soft-dirty works.
+	 */
+	pte_t ptent = *pte;
+
+	if (pte_present(ptent)) {
+		pte_t old_pte;
+
+		if (pte_is_pinned(vma, addr, ptent))
+			return;
+		old_pte = ptep_modify_prot_start(vma, addr, pte);
+		ptent = pte_wrprotect(old_pte);
+		ptent = pte_clear_soft_dirty(ptent);
+		ptep_modify_prot_commit(vma, addr, pte, old_pte, ptent);
+	} else if (is_swap_pte(ptent)) {
+		ptent = pte_swp_clear_soft_dirty(ptent);
+		set_pte_at(vma->vm_mm, addr, pte, ptent);
+	}
+}
+#else
+static inline void clear_soft_dirty(struct vm_area_struct *vma,
+		unsigned long addr, pte_t *pte)
+{
+}
+#endif
+
+#if defined(CONFIG_MEM_SOFT_DIRTY) && defined(CONFIG_TRANSPARENT_HUGEPAGE)
+static inline void clear_soft_dirty_pmd(struct vm_area_struct *vma,
+		unsigned long addr, pmd_t *pmdp)
+{
+	pmd_t old, pmd = *pmdp;
+
+	if (pmd_present(pmd)) {
+		/* See comment in change_huge_pmd() */
+		old = pmdp_invalidate(vma, addr, pmdp);
+		if (pmd_dirty(old))
+			pmd = pmd_mkdirty(pmd);
+		if (pmd_young(old))
+			pmd = pmd_mkyoung(pmd);
+
+		pmd = pmd_wrprotect(pmd);
+		pmd = pmd_clear_soft_dirty(pmd);
+
+		set_pmd_at(vma->vm_mm, addr, pmdp, pmd);
+	} else if (is_migration_entry(pmd_to_swp_entry(pmd))) {
+		pmd = pmd_swp_clear_soft_dirty(pmd);
+		set_pmd_at(vma->vm_mm, addr, pmdp, pmd);
+	}
+}
+#else
+static inline void clear_soft_dirty_pmd(struct vm_area_struct *vma,
+		unsigned long addr, pmd_t *pmdp)
+{
+}
+#endif
+
+static int clear_refs_pte_range(pmd_t *pmd, unsigned long addr,
+				unsigned long end, struct mm_walk *walk)
+{
+	struct clear_refs_private *cp = walk->private;
+	struct vm_area_struct *vma = walk->vma;
+	pte_t *pte, ptent;
+	spinlock_t *ptl;
+	struct page *page;
+
+	ptl = pmd_trans_huge_lock(pmd, vma);
+	if (ptl) {
+		if (cp->type == CLEAR_REFS_SOFT_DIRTY) {
+			clear_soft_dirty_pmd(vma, addr, pmd);
+			goto out;
+		}
+
+		if (!pmd_present(*pmd))
+			goto out;
+
+		page = pmd_page(*pmd);
+
+		/* Clear accessed and referenced bits. */
+		pmdp_test_and_clear_young(vma, addr, pmd);
+		test_and_clear_page_young(page);
+		ClearPageReferenced(page);
+out:
+		spin_unlock(ptl);
+		return 0;
+	}
+
+	if (pmd_trans_unstable(pmd))
+		return 0;
+
+	pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl);
+	for (; addr != end; pte++, addr += PAGE_SIZE) {
+		ptent = *pte;
+
+		if (cp->type == CLEAR_REFS_SOFT_DIRTY) {
+			clear_soft_dirty(vma, addr, pte);
+			continue;
+		}
+
+		if (!pte_present(ptent))
+			continue;
+
+		page = vm_normal_page(vma, addr, ptent);
+		if (!page)
+			continue;
+
+		/* Clear accessed and referenced bits. */
+		ptep_test_and_clear_young(vma, addr, pte);
+		test_and_clear_page_young(page);
+		ClearPageReferenced(page);
+	}
+	pte_unmap_unlock(pte - 1, ptl);
+	cond_resched();
+	return 0;
+}
+
+static int clear_refs_test_walk(unsigned long start, unsigned long end,
+				struct mm_walk *walk)
+{
+	struct clear_refs_private *cp = walk->private;
+	struct vm_area_struct *vma = walk->vma;
+
+	if (vma->vm_flags & VM_PFNMAP)
+		return 1;
+
+	/*
+	 * Writing 1 to /proc/pid/clear_refs affects all pages.
+	 * Writing 2 to /proc/pid/clear_refs only affects anonymous pages.
+	 * Writing 3 to /proc/pid/clear_refs only affects file mapped pages.
+	 * Writing 4 to /proc/pid/clear_refs affects all pages.
+	 */
+	if (cp->type == CLEAR_REFS_ANON && vma->vm_file)
+		return 1;
+	if (cp->type == CLEAR_REFS_MAPPED && !vma->vm_file)
+		return 1;
+	return 0;
+}
+
+static const struct mm_walk_ops clear_refs_walk_ops = {
+	.pmd_entry		= clear_refs_pte_range,
+	.test_walk		= clear_refs_test_walk,
+};
+
+static ssize_t clear_refs_write(struct file *file, const char __user *buf,
+				size_t count, loff_t *ppos)
+{
+	struct task_struct *task;
+	char buffer[PROC_NUMBUF];
+	struct mm_struct *mm;
+	struct vm_area_struct *vma;
+	enum clear_refs_types type;
+	int itype;
+	int rv;
+
+	memset(buffer, 0, sizeof(buffer));
+	if (count > sizeof(buffer) - 1)
+		count = sizeof(buffer) - 1;
+	if (copy_from_user(buffer, buf, count))
+		return -EFAULT;
+	rv = kstrtoint(strstrip(buffer), 10, &itype);
+	if (rv < 0)
+		return rv;
+	type = (enum clear_refs_types)itype;
+	if (type < CLEAR_REFS_ALL || type >= CLEAR_REFS_LAST)
+		return -EINVAL;
+
+	task = get_proc_task(file_inode(file));
+	if (!task)
+		return -ESRCH;
+	mm = get_task_mm(task);
+	if (mm) {
+		struct mmu_notifier_range range;
+		struct clear_refs_private cp = {
+			.type = type,
+		};
+
+		if (mmap_write_lock_killable(mm)) {
+			count = -EINTR;
+			goto out_mm;
+		}
+		if (type == CLEAR_REFS_MM_HIWATER_RSS) {
+			/*
+			 * Writing 5 to /proc/pid/clear_refs resets the peak
+			 * resident set size to this mm's current rss value.
+			 */
+			reset_mm_hiwater_rss(mm);
+			goto out_unlock;
+		}
+
+		if (type == CLEAR_REFS_SOFT_DIRTY) {
+			for (vma = mm->mmap; vma; vma = vma->vm_next) {
+				if (!(vma->vm_flags & VM_SOFTDIRTY))
+					continue;
+				vma->vm_flags &= ~VM_SOFTDIRTY;
+				vma_set_page_prot(vma);
+			}
+
+			inc_tlb_flush_pending(mm);
+			mmu_notifier_range_init(&range, MMU_NOTIFY_SOFT_DIRTY,
+						0, NULL, mm, 0, -1UL);
+			mmu_notifier_invalidate_range_start(&range);
+		}
+		walk_page_range(mm, 0, mm->highest_vm_end, &clear_refs_walk_ops,
+				&cp);
+		if (type == CLEAR_REFS_SOFT_DIRTY) {
+			mmu_notifier_invalidate_range_end(&range);
+			flush_tlb_mm(mm);
+			dec_tlb_flush_pending(mm);
+		}
+out_unlock:
+		mmap_write_unlock(mm);
+out_mm:
+		mmput(mm);
+	}
+	put_task_struct(task);
+
+	return count;
+}
+
+const struct file_operations proc_clear_refs_operations = {
+	.write		= clear_refs_write,
+	.llseek		= noop_llseek,
+};
+
+typedef struct {
+	u64 pme;
+} pagemap_entry_t;
+
+struct pagemapread {
+	int pos, len;		/* units: PM_ENTRY_BYTES, not bytes */
+	pagemap_entry_t *buffer;
+	bool show_pfn;
+};
+
+#define PAGEMAP_WALK_SIZE	(PMD_SIZE)
+#define PAGEMAP_WALK_MASK	(PMD_MASK)
+
+#define PM_ENTRY_BYTES		sizeof(pagemap_entry_t)
+#define PM_PFRAME_BITS		55
+#define PM_PFRAME_MASK		GENMASK_ULL(PM_PFRAME_BITS - 1, 0)
+#define PM_SOFT_DIRTY		BIT_ULL(55)
+#define PM_MMAP_EXCLUSIVE	BIT_ULL(56)
+#define PM_FILE			BIT_ULL(61)
+#define PM_SWAP			BIT_ULL(62)
+#define PM_PRESENT		BIT_ULL(63)
+
+#define PM_END_OF_BUFFER    1
+
+static inline pagemap_entry_t make_pme(u64 frame, u64 flags)
+{
+	return (pagemap_entry_t) { .pme = (frame & PM_PFRAME_MASK) | flags };
+}
+
+static int add_to_pagemap(unsigned long addr, pagemap_entry_t *pme,
+			  struct pagemapread *pm)
+{
+	pm->buffer[pm->pos++] = *pme;
+	if (pm->pos >= pm->len)
+		return PM_END_OF_BUFFER;
+	return 0;
+}
+
+static int pagemap_pte_hole(unsigned long start, unsigned long end,
+			    __always_unused int depth, struct mm_walk *walk)
+{
+	struct pagemapread *pm = walk->private;
+	unsigned long addr = start;
+	int err = 0;
+
+	while (addr < end) {
+		struct vm_area_struct *vma = find_vma(walk->mm, addr);
+		pagemap_entry_t pme = make_pme(0, 0);
+		/* End of address space hole, which we mark as non-present. */
+		unsigned long hole_end;
+
+		if (vma)
+			hole_end = min(end, vma->vm_start);
+		else
+			hole_end = end;
+
+		for (; addr < hole_end; addr += PAGE_SIZE) {
+			err = add_to_pagemap(addr, &pme, pm);
+			if (err)
+				goto out;
+		}
+
+		if (!vma)
+			break;
+
+		/* Addresses in the VMA. */
+		if (vma->vm_flags & VM_SOFTDIRTY)
+			pme = make_pme(0, PM_SOFT_DIRTY);
+		for (; addr < min(end, vma->vm_end); addr += PAGE_SIZE) {
+			err = add_to_pagemap(addr, &pme, pm);
+			if (err)
+				goto out;
+		}
+	}
+out:
+	return err;
+}
+
+static pagemap_entry_t pte_to_pagemap_entry(struct pagemapread *pm,
+		struct vm_area_struct *vma, unsigned long addr, pte_t pte)
+{
+	u64 frame = 0, flags = 0;
+	struct page *page = NULL;
+	bool migration = false;
+
+	if (pte_present(pte)) {
+		if (pm->show_pfn)
+			frame = pte_pfn(pte);
+		flags |= PM_PRESENT;
+		page = vm_normal_page(vma, addr, pte);
+		if (pte_soft_dirty(pte))
+			flags |= PM_SOFT_DIRTY;
+	} else if (is_swap_pte(pte)) {
+		swp_entry_t entry;
+		if (pte_swp_soft_dirty(pte))
+			flags |= PM_SOFT_DIRTY;
+		entry = pte_to_swp_entry(pte);
+		if (pm->show_pfn)
+			frame = swp_type(entry) |
+				(swp_offset(entry) << MAX_SWAPFILES_SHIFT);
+		flags |= PM_SWAP;
+		if (is_migration_entry(entry)) {
+			migration = true;
+			page = migration_entry_to_page(entry);
+		}
+
+		if (is_device_private_entry(entry))
+			page = device_private_entry_to_page(entry);
+	}
+
+	if (page && !PageAnon(page))
+		flags |= PM_FILE;
+	if (page && !migration && page_mapcount(page) == 1)
+		flags |= PM_MMAP_EXCLUSIVE;
+	if (vma->vm_flags & VM_SOFTDIRTY)
+		flags |= PM_SOFT_DIRTY;
+
+	return make_pme(frame, flags);
+}
+
+static int pagemap_pmd_range(pmd_t *pmdp, unsigned long addr, unsigned long end,
+			     struct mm_walk *walk)
+{
+	struct vm_area_struct *vma = walk->vma;
+	struct pagemapread *pm = walk->private;
+	spinlock_t *ptl;
+	pte_t *pte, *orig_pte;
+	int err = 0;
+#ifdef CONFIG_TRANSPARENT_HUGEPAGE
+	bool migration = false;
+
+	ptl = pmd_trans_huge_lock(pmdp, vma);
+	if (ptl) {
+		u64 flags = 0, frame = 0;
+		pmd_t pmd = *pmdp;
+		struct page *page = NULL;
+
+		if (vma->vm_flags & VM_SOFTDIRTY)
+			flags |= PM_SOFT_DIRTY;
+
+		if (pmd_present(pmd)) {
+			page = pmd_page(pmd);
+
+			flags |= PM_PRESENT;
+			if (pmd_soft_dirty(pmd))
+				flags |= PM_SOFT_DIRTY;
+			if (pm->show_pfn)
+				frame = pmd_pfn(pmd) +
+					((addr & ~PMD_MASK) >> PAGE_SHIFT);
+		}
+#ifdef CONFIG_ARCH_ENABLE_THP_MIGRATION
+		else if (is_swap_pmd(pmd)) {
+			swp_entry_t entry = pmd_to_swp_entry(pmd);
+			unsigned long offset;
+
+			if (pm->show_pfn) {
+				offset = swp_offset(entry) +
+					((addr & ~PMD_MASK) >> PAGE_SHIFT);
+				frame = swp_type(entry) |
+					(offset << MAX_SWAPFILES_SHIFT);
+			}
+			flags |= PM_SWAP;
+			if (pmd_swp_soft_dirty(pmd))
+				flags |= PM_SOFT_DIRTY;
+			VM_BUG_ON(!is_pmd_migration_entry(pmd));
+			migration = is_migration_entry(entry);
+			page = migration_entry_to_page(entry);
+		}
+#endif
+
+		if (page && !migration && page_mapcount(page) == 1)
+			flags |= PM_MMAP_EXCLUSIVE;
+
+		for (; addr != end; addr += PAGE_SIZE) {
+			pagemap_entry_t pme = make_pme(frame, flags);
+
+			err = add_to_pagemap(addr, &pme, pm);
+			if (err)
+				break;
+			if (pm->show_pfn) {
+				if (flags & PM_PRESENT)
+					frame++;
+				else if (flags & PM_SWAP)
+					frame += (1 << MAX_SWAPFILES_SHIFT);
+			}
+		}
+		spin_unlock(ptl);
+		return err;
+	}
+
+	if (pmd_trans_unstable(pmdp))
+		return 0;
+#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
+
+	/*
+	 * We can assume that @vma always points to a valid one and @end never
+	 * goes beyond vma->vm_end.
+	 */
+	orig_pte = pte = pte_offset_map_lock(walk->mm, pmdp, addr, &ptl);
+	for (; addr < end; pte++, addr += PAGE_SIZE) {
+		pagemap_entry_t pme;
+
+		pme = pte_to_pagemap_entry(pm, vma, addr, *pte);
+		err = add_to_pagemap(addr, &pme, pm);
+		if (err)
+			break;
+	}
+	pte_unmap_unlock(orig_pte, ptl);
+
+	cond_resched();
+
+	return err;
+}
+
+#ifdef CONFIG_HUGETLB_PAGE
+/* This function walks within one hugetlb entry in the single call */
+static int pagemap_hugetlb_range(pte_t *ptep, unsigned long hmask,
+				 unsigned long addr, unsigned long end,
+				 struct mm_walk *walk)
+{
+	struct pagemapread *pm = walk->private;
+	struct vm_area_struct *vma = walk->vma;
+	u64 flags = 0, frame = 0;
+	int err = 0;
+	pte_t pte;
+
+	if (vma->vm_flags & VM_SOFTDIRTY)
+		flags |= PM_SOFT_DIRTY;
+
+	pte = huge_ptep_get(ptep);
+	if (pte_present(pte)) {
+		struct page *page = pte_page(pte);
+
+		if (!PageAnon(page))
+			flags |= PM_FILE;
+
+		if (page_mapcount(page) == 1)
+			flags |= PM_MMAP_EXCLUSIVE;
+
+		flags |= PM_PRESENT;
+		if (pm->show_pfn)
+			frame = pte_pfn(pte) +
+				((addr & ~hmask) >> PAGE_SHIFT);
+	}
+
+	for (; addr != end; addr += PAGE_SIZE) {
+		pagemap_entry_t pme = make_pme(frame, flags);
+
+		err = add_to_pagemap(addr, &pme, pm);
+		if (err)
+			return err;
+		if (pm->show_pfn && (flags & PM_PRESENT))
+			frame++;
+	}
+
+	cond_resched();
+
+	return err;
+}
+#else
+#define pagemap_hugetlb_range	NULL
+#endif /* HUGETLB_PAGE */
+
+static const struct mm_walk_ops pagemap_ops = {
+	.pmd_entry	= pagemap_pmd_range,
+	.pte_hole	= pagemap_pte_hole,
+	.hugetlb_entry	= pagemap_hugetlb_range,
+};
+
+/*
+ * /proc/pid/pagemap - an array mapping virtual pages to pfns
+ *
+ * For each page in the address space, this file contains one 64-bit entry
+ * consisting of the following:
+ *
+ * Bits 0-54  page frame number (PFN) if present
+ * Bits 0-4   swap type if swapped
+ * Bits 5-54  swap offset if swapped
+ * Bit  55    pte is soft-dirty (see Documentation/admin-guide/mm/soft-dirty.rst)
+ * Bit  56    page exclusively mapped
+ * Bits 57-60 zero
+ * Bit  61    page is file-page or shared-anon
+ * Bit  62    page swapped
+ * Bit  63    page present
+ *
+ * If the page is not present but in swap, then the PFN contains an
+ * encoding of the swap file number and the page's offset into the
+ * swap. Unmapped pages return a null PFN. This allows determining
+ * precisely which pages are mapped (or in swap) and comparing mapped
+ * pages between processes.
+ *
+ * Efficient users of this interface will use /proc/pid/maps to
+ * determine which areas of memory are actually mapped and llseek to
+ * skip over unmapped regions.
+ */
+static ssize_t pagemap_read(struct file *file, char __user *buf,
+			    size_t count, loff_t *ppos)
+{
+	struct mm_struct *mm = file->private_data;
+	struct pagemapread pm;
+	unsigned long src;
+	unsigned long svpfn;
+	unsigned long start_vaddr;
+	unsigned long end_vaddr;
+	int ret = 0, copied = 0;
+
+	if (!mm || !mmget_not_zero(mm))
+		goto out;
+
+	ret = -EINVAL;
+	/* file position must be aligned */
+	if ((*ppos % PM_ENTRY_BYTES) || (count % PM_ENTRY_BYTES))
+		goto out_mm;
+
+	ret = 0;
+	if (!count)
+		goto out_mm;
+
+	/* do not disclose physical addresses: attack vector */
+	pm.show_pfn = file_ns_capable(file, &init_user_ns, CAP_SYS_ADMIN);
+
+	pm.len = (PAGEMAP_WALK_SIZE >> PAGE_SHIFT);
+	pm.buffer = kmalloc_array(pm.len, PM_ENTRY_BYTES, GFP_KERNEL);
+	ret = -ENOMEM;
+	if (!pm.buffer)
+		goto out_mm;
+
+	src = *ppos;
+	svpfn = src / PM_ENTRY_BYTES;
+	end_vaddr = mm->task_size;
+
+	/* watch out for wraparound */
+	start_vaddr = end_vaddr;
+	if (svpfn <= (ULONG_MAX >> PAGE_SHIFT))
+		start_vaddr = untagged_addr(svpfn << PAGE_SHIFT);
+
+	/* Ensure the address is inside the task */
+	if (start_vaddr > mm->task_size)
+		start_vaddr = end_vaddr;
+
+	/*
+	 * The odds are that this will stop walking way
+	 * before end_vaddr, because the length of the
+	 * user buffer is tracked in "pm", and the walk
+	 * will stop when we hit the end of the buffer.
+	 */
+	ret = 0;
+	while (count && (start_vaddr < end_vaddr)) {
+		int len;
+		unsigned long end;
+
+		pm.pos = 0;
+		end = (start_vaddr + PAGEMAP_WALK_SIZE) & PAGEMAP_WALK_MASK;
+		/* overflow ? */
+		if (end < start_vaddr || end > end_vaddr)
+			end = end_vaddr;
+		ret = mmap_read_lock_killable(mm);
+		if (ret)
+			goto out_free;
+		ret = walk_page_range(mm, start_vaddr, end, &pagemap_ops, &pm);
+		mmap_read_unlock(mm);
+		start_vaddr = end;
+
+		len = min(count, PM_ENTRY_BYTES * pm.pos);
+		if (copy_to_user(buf, pm.buffer, len)) {
+			ret = -EFAULT;
+			goto out_free;
+		}
+		copied += len;
+		buf += len;
+		count -= len;
+	}
+	*ppos += copied;
+	if (!ret || ret == PM_END_OF_BUFFER)
+		ret = copied;
+
+out_free:
+	kfree(pm.buffer);
+out_mm:
+	mmput(mm);
+out:
+	return ret;
+}
+
+static int pagemap_open(struct inode *inode, struct file *file)
+{
+	struct mm_struct *mm;
+
+	mm = proc_mem_open(inode, PTRACE_MODE_READ);
+	if (IS_ERR(mm))
+		return PTR_ERR(mm);
+	file->private_data = mm;
+	return 0;
+}
+
+static int pagemap_release(struct inode *inode, struct file *file)
+{
+	struct mm_struct *mm = file->private_data;
+
+	if (mm)
+		mmdrop(mm);
+	return 0;
+}
+
+const struct file_operations proc_pagemap_operations = {
+	.llseek		= mem_lseek, /* borrow this */
+	.read		= pagemap_read,
+	.open		= pagemap_open,
+	.release	= pagemap_release,
+};
+#endif /* CONFIG_PROC_PAGE_MONITOR */
+
+#ifdef CONFIG_NUMA
+
+struct numa_maps {
+	unsigned long pages;
+	unsigned long anon;
+	unsigned long active;
+	unsigned long writeback;
+	unsigned long mapcount_max;
+	unsigned long dirty;
+	unsigned long swapcache;
+	unsigned long node[MAX_NUMNODES];
+};
+
+struct numa_maps_private {
+	struct proc_maps_private proc_maps;
+	struct numa_maps md;
+};
+
+static void gather_stats(struct page *page, struct numa_maps *md, int pte_dirty,
+			unsigned long nr_pages)
+{
+	int count = page_mapcount(page);
+
+	md->pages += nr_pages;
+	if (pte_dirty || PageDirty(page))
+		md->dirty += nr_pages;
+
+	if (PageSwapCache(page))
+		md->swapcache += nr_pages;
+
+	if (PageActive(page) || PageUnevictable(page))
+		md->active += nr_pages;
+
+	if (PageWriteback(page))
+		md->writeback += nr_pages;
+
+	if (PageAnon(page))
+		md->anon += nr_pages;
+
+	if (count > md->mapcount_max)
+		md->mapcount_max = count;
+
+	md->node[page_to_nid(page)] += nr_pages;
+}
+
+static struct page *can_gather_numa_stats(pte_t pte, struct vm_area_struct *vma,
+		unsigned long addr)
+{
+	struct page *page;
+	int nid;
+
+	if (!pte_present(pte))
+		return NULL;
+
+	page = vm_normal_page(vma, addr, pte);
+	if (!page)
+		return NULL;
+
+	if (PageReserved(page))
+		return NULL;
+
+	nid = page_to_nid(page);
+	if (!node_isset(nid, node_states[N_MEMORY]))
+		return NULL;
+
+	return page;
+}
+
+#ifdef CONFIG_TRANSPARENT_HUGEPAGE
+static struct page *can_gather_numa_stats_pmd(pmd_t pmd,
+					      struct vm_area_struct *vma,
+					      unsigned long addr)
+{
+	struct page *page;
+	int nid;
+
+	if (!pmd_present(pmd))
+		return NULL;
+
+	page = vm_normal_page_pmd(vma, addr, pmd);
+	if (!page)
+		return NULL;
+
+	if (PageReserved(page))
+		return NULL;
+
+	nid = page_to_nid(page);
+	if (!node_isset(nid, node_states[N_MEMORY]))
+		return NULL;
+
+	return page;
+}
+#endif
+
+static int gather_pte_stats(pmd_t *pmd, unsigned long addr,
+		unsigned long end, struct mm_walk *walk)
+{
+	struct numa_maps *md = walk->private;
+	struct vm_area_struct *vma = walk->vma;
+	spinlock_t *ptl;
+	pte_t *orig_pte;
+	pte_t *pte;
+
+#ifdef CONFIG_TRANSPARENT_HUGEPAGE
+	ptl = pmd_trans_huge_lock(pmd, vma);
+	if (ptl) {
+		struct page *page;
+
+		page = can_gather_numa_stats_pmd(*pmd, vma, addr);
+		if (page)
+			gather_stats(page, md, pmd_dirty(*pmd),
+				     HPAGE_PMD_SIZE/PAGE_SIZE);
+		spin_unlock(ptl);
+		return 0;
+	}
+
+	if (pmd_trans_unstable(pmd))
+		return 0;
+#endif
+	orig_pte = pte = pte_offset_map_lock(walk->mm, pmd, addr, &ptl);
+	do {
+		struct page *page = can_gather_numa_stats(*pte, vma, addr);
+		if (!page)
+			continue;
+		gather_stats(page, md, pte_dirty(*pte), 1);
+
+	} while (pte++, addr += PAGE_SIZE, addr != end);
+	pte_unmap_unlock(orig_pte, ptl);
+	cond_resched();
+	return 0;
+}
+#ifdef CONFIG_HUGETLB_PAGE
+static int gather_hugetlb_stats(pte_t *pte, unsigned long hmask,
+		unsigned long addr, unsigned long end, struct mm_walk *walk)
+{
+	pte_t huge_pte = huge_ptep_get(pte);
+	struct numa_maps *md;
+	struct page *page;
+
+	if (!pte_present(huge_pte))
+		return 0;
+
+	page = pte_page(huge_pte);
+	if (!page)
+		return 0;
+
+	md = walk->private;
+	gather_stats(page, md, pte_dirty(huge_pte), 1);
+	return 0;
+}
+
+#else
+static int gather_hugetlb_stats(pte_t *pte, unsigned long hmask,
+		unsigned long addr, unsigned long end, struct mm_walk *walk)
+{
+	return 0;
+}
+#endif
+
+static const struct mm_walk_ops show_numa_ops = {
+	.hugetlb_entry = gather_hugetlb_stats,
+	.pmd_entry = gather_pte_stats,
+};
+
+/*
+ * Display pages allocated per node and memory policy via /proc.
+ */
+static int show_numa_map(struct seq_file *m, void *v)
+{
+	struct numa_maps_private *numa_priv = m->private;
+	struct proc_maps_private *proc_priv = &numa_priv->proc_maps;
+	struct vm_area_struct *vma = v;
+	struct numa_maps *md = &numa_priv->md;
+	struct file *file = vma->vm_file;
+	struct mm_struct *mm = vma->vm_mm;
+	struct mempolicy *pol;
+	char buffer[64];
+	int nid;
+
+	if (!mm)
+		return 0;
+
+	/* Ensure we start with an empty set of numa_maps statistics. */
+	memset(md, 0, sizeof(*md));
+
+	pol = __get_vma_policy(vma, vma->vm_start);
+	if (pol) {
+		mpol_to_str(buffer, sizeof(buffer), pol);
+		mpol_cond_put(pol);
+	} else {
+		mpol_to_str(buffer, sizeof(buffer), proc_priv->task_mempolicy);
+	}
+
+	seq_printf(m, "%08lx %s", vma->vm_start, buffer);
+
+	if (file) {
+		seq_puts(m, " file=");
+		seq_file_path(m, file, "\n\t= ");
+	} else if (vma->vm_start <= mm->brk && vma->vm_end >= mm->start_brk) {
+		seq_puts(m, " heap");
+	} else if (is_stack(vma)) {
+		seq_puts(m, " stack");
+	}
+
+	if (is_vm_hugetlb_page(vma))
+		seq_puts(m, " huge");
+
+	/* mmap_lock is held by m_start */
+	walk_page_vma(vma, &show_numa_ops, md);
+
+	if (!md->pages)
+		goto out;
+
+	if (md->anon)
+		seq_printf(m, " anon=%lu", md->anon);
+
+	if (md->dirty)
+		seq_printf(m, " dirty=%lu", md->dirty);
+
+	if (md->pages != md->anon && md->pages != md->dirty)
+		seq_printf(m, " mapped=%lu", md->pages);
+
+	if (md->mapcount_max > 1)
+		seq_printf(m, " mapmax=%lu", md->mapcount_max);
+
+	if (md->swapcache)
+		seq_printf(m, " swapcache=%lu", md->swapcache);
+
+	if (md->active < md->pages && !is_vm_hugetlb_page(vma))
+		seq_printf(m, " active=%lu", md->active);
+
+	if (md->writeback)
+		seq_printf(m, " writeback=%lu", md->writeback);
+
+	for_each_node_state(nid, N_MEMORY)
+		if (md->node[nid])
+			seq_printf(m, " N%d=%lu", nid, md->node[nid]);
+
+	seq_printf(m, " kernelpagesize_kB=%lu", vma_kernel_pagesize(vma) >> 10);
+out:
+	seq_putc(m, '\n');
+	return 0;
+}
+
+static const struct seq_operations proc_pid_numa_maps_op = {
+	.start  = m_start,
+	.next   = m_next,
+	.stop   = m_stop,
+	.show   = show_numa_map,
+};
+
+static int pid_numa_maps_open(struct inode *inode, struct file *file)
+{
+	return proc_maps_open(inode, file, &proc_pid_numa_maps_op,
+				sizeof(struct numa_maps_private));
+}
+
+const struct file_operations proc_pid_numa_maps_operations = {
+	.open		= pid_numa_maps_open,
+	.read		= seq_read,
+	.llseek		= seq_lseek,
+	.release	= proc_map_release,
+};
+
+#endif /* CONFIG_NUMA */