treewide: refresh kmalloc_obj() conversionsgrafted

This is another run of the Coccinelle script for converting kmalloc()
family of allocations to kmalloc_obj() via the existing rules in
scripts/coccinelle/api/kmalloc_objs.cocci

This catches both the set of kmalloc() uses added since the first
kmalloc_obj() conversions in v7.0 and adds a large group missed in the
first pass due to Coccinelle not interacting well with the cleanup.h
scoped_...() family of macros[1]. I worked around this with spatch's
"--macro-file" argument to a file with all the scoped_...() macros mapped
to Coccinelle's YACFE_ITERATOR[2] as that was the closest viable control
flow indicator I could find.

Build tested allmodconfig on x86, arm64, arm, loongarch, mips, powerpc,
riscv, and s390 with no new warnings.

Link: https://lore.kernel.org/lkml/202609021314.8A9C0B8@keescook/ [1]
Link: https://github.com/coccinelle/coccinelle/blob/master/standard.h [2]
Signed-off-by: Kees Cook <kees+treewide@kernel.org>

1 files changed, 3631 insertions, 0 deletions

diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c
new file mode 100644
index 000000000..5c54aebe2
--- /dev/null
+++ b/fs/proc/task_mmu.c
@@ -0,0 +1,3631 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/pagewalk.h>
+#include <linux/mm_inline.h>
+#include <linux/hugetlb.h>
+#include <linux/huge_mm.h>
+#include <linux/mount.h>
+#include <linux/ksm.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/leafops.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 <linux/minmax.h>
+#include <linux/overflow.h>
+#include <linux/buildid.h>
+
+#include <asm/elf.h>
+#include <asm/tlb.h>
+#include <asm/tlbflush.h>
+#include "internal.h"
+
+#define SENTINEL_VMA_END	-1
+#define SENTINEL_VMA_GATE	-2
+
+#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_sum(mm, MM_ANONPAGES);
+	file = get_mm_counter_sum(mm, MM_FILEPAGES);
+	shmem = get_mm_counter_sum(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_sum(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_sum(mm, MM_FILEPAGES) +
+			get_mm_counter_sum(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_sum(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
+
+#ifdef CONFIG_PER_VMA_LOCK
+
+static inline int lock_ctx_mm(struct proc_maps_locking_ctx *lock_ctx)
+{
+	int ret = mmap_read_lock_killable(lock_ctx->mm);
+
+	if (!ret)
+		lock_ctx->mmap_locked = true;
+
+	return ret;
+}
+
+static inline void unlock_ctx_mm(struct proc_maps_locking_ctx *lock_ctx)
+{
+	mmap_read_unlock(lock_ctx->mm);
+	lock_ctx->mmap_locked = false;
+}
+
+static void reset_lock_ctx(struct proc_maps_locking_ctx *lock_ctx)
+{
+	lock_ctx->locked_vma = NULL;
+	lock_ctx->mmap_locked = false;
+}
+
+static void unlock_ctx_vma(struct proc_maps_locking_ctx *lock_ctx)
+{
+	if (lock_ctx->locked_vma) {
+		vma_end_read(lock_ctx->locked_vma);
+		lock_ctx->locked_vma = NULL;
+	}
+}
+
+static inline bool lock_vma_range(struct seq_file *m,
+				  struct proc_maps_locking_ctx *lock_ctx)
+{
+	rcu_read_lock();
+	reset_lock_ctx(lock_ctx);
+
+	return true;
+}
+
+static inline void unlock_vma_range(struct proc_maps_locking_ctx *lock_ctx)
+{
+	if (lock_ctx->mmap_locked) {
+		unlock_ctx_mm(lock_ctx);
+	} else {
+		unlock_ctx_vma(lock_ctx);
+		rcu_read_unlock();
+	}
+}
+
+static struct vm_area_struct *get_next_vma(struct proc_maps_private *priv,
+					   loff_t last_pos)
+{
+	struct proc_maps_locking_ctx *lock_ctx = &priv->lock_ctx;
+	struct vm_area_struct *vma;
+
+	if (lock_ctx->mmap_locked)
+		return vma_next(&priv->iter);
+
+	unlock_ctx_vma(lock_ctx);
+	vma = lock_next_vma(lock_ctx->mm, &priv->iter, last_pos);
+	if (!IS_ERR_OR_NULL(vma))
+		lock_ctx->locked_vma = vma;
+
+	return vma;
+}
+
+static inline bool fallback_to_mmap_lock(struct proc_maps_private *priv,
+					 loff_t pos)
+{
+	struct proc_maps_locking_ctx *lock_ctx = &priv->lock_ctx;
+
+	if (lock_ctx->mmap_locked)
+		return false;
+
+	rcu_read_unlock();
+	mmap_read_lock(lock_ctx->mm);
+	/* Reinitialize the iterator after taking mmap_lock */
+	vma_iter_set(&priv->iter, pos);
+	lock_ctx->mmap_locked = true;
+
+	return true;
+}
+
+static inline void drop_rcu(struct proc_maps_private *priv)
+{
+	if (priv->lock_ctx.mmap_locked)
+		return;
+
+	rcu_read_unlock();
+}
+
+static inline void reacquire_rcu(struct proc_maps_private *priv)
+{
+	if (priv->lock_ctx.mmap_locked)
+		return;
+
+	rcu_read_lock();
+	/* Reinitialize the iterator. */
+	vma_iter_set(&priv->iter, priv->lock_ctx.locked_vma->vm_end);
+}
+
+#else /* CONFIG_PER_VMA_LOCK */
+
+static inline int lock_ctx_mm(struct proc_maps_locking_ctx *lock_ctx)
+{
+	return mmap_read_lock_killable(lock_ctx->mm);
+}
+
+static inline void unlock_ctx_mm(struct proc_maps_locking_ctx *lock_ctx)
+{
+	mmap_read_unlock(lock_ctx->mm);
+}
+
+static inline bool lock_vma_range(struct seq_file *m,
+				  struct proc_maps_locking_ctx *lock_ctx)
+{
+	return lock_ctx_mm(lock_ctx) == 0;
+}
+
+static inline void unlock_vma_range(struct proc_maps_locking_ctx *lock_ctx)
+{
+	unlock_ctx_mm(lock_ctx);
+}
+
+static struct vm_area_struct *get_next_vma(struct proc_maps_private *priv,
+					   loff_t last_pos)
+{
+	return vma_next(&priv->iter);
+}
+
+static inline bool fallback_to_mmap_lock(struct proc_maps_private *priv,
+					 loff_t pos)
+{
+	return false;
+}
+
+static inline void drop_rcu(struct proc_maps_private *priv) {}
+static inline void reacquire_rcu(struct proc_maps_private *priv) {}
+
+#endif /* CONFIG_PER_VMA_LOCK */
+
+static struct vm_area_struct *proc_get_vma(struct seq_file *m, loff_t *ppos)
+{
+	struct proc_maps_private *priv = m->private;
+	struct vm_area_struct *vma;
+
+retry:
+	vma = get_next_vma(priv, *ppos);
+	/* EINTR of EAGAIN is possible */
+	if (IS_ERR(vma)) {
+		if (PTR_ERR(vma) == -EAGAIN && fallback_to_mmap_lock(priv, *ppos))
+			goto retry;
+
+		return vma;
+	}
+
+	/* Store previous position to be able to restart if needed */
+	priv->last_pos = *ppos;
+	if (vma) {
+		/*
+		 * Track the end of the reported vma to ensure position changes
+		 * even if previous vma was merged with the next vma and we
+		 * found the extended vma with the same vm_start.
+		 */
+		*ppos = vma->vm_end;
+	} else {
+		*ppos = SENTINEL_VMA_GATE;
+		vma = get_gate_vma(priv->lock_ctx.mm);
+	}
+
+	return vma;
+}
+
+static void *m_start(struct seq_file *m, loff_t *ppos)
+{
+	struct proc_maps_private *priv = m->private;
+	struct proc_maps_locking_ctx *lock_ctx;
+	loff_t last_addr = *ppos;
+	struct mm_struct *mm;
+
+	/* See m_next(). Zero at the start or after lseek. */
+	if (last_addr == SENTINEL_VMA_END)
+		return NULL;
+
+	priv->task = get_proc_task(priv->inode);
+	if (!priv->task)
+		return ERR_PTR(-ESRCH);
+
+	lock_ctx = &priv->lock_ctx;
+	mm = lock_ctx->mm;
+	if (!mm || !mmget_not_zero(mm)) {
+		put_task_struct(priv->task);
+		priv->task = NULL;
+		return NULL;
+	}
+
+	if (!lock_vma_range(m, lock_ctx)) {
+		mmput(mm);
+		put_task_struct(priv->task);
+		priv->task = NULL;
+		return ERR_PTR(-EINTR);
+	}
+
+	/*
+	 * Reset current position if last_addr was set before
+	 * and it's not a sentinel.
+	 */
+	if (last_addr > 0)
+		*ppos = last_addr = priv->last_pos;
+	vma_iter_init(&priv->iter, mm, (unsigned long)last_addr);
+	hold_task_mempolicy(priv);
+	if (last_addr == SENTINEL_VMA_GATE)
+		return get_gate_vma(mm);
+
+	return proc_get_vma(m, ppos);
+}
+
+static void *m_next(struct seq_file *m, void *v, loff_t *ppos)
+{
+	if (*ppos == SENTINEL_VMA_GATE) {
+		*ppos = SENTINEL_VMA_END;
+		return NULL;
+	}
+	return proc_get_vma(m, ppos);
+}
+
+static void m_stop(struct seq_file *m, void *v)
+{
+	struct proc_maps_private *priv = m->private;
+	struct mm_struct *mm = priv->lock_ctx.mm;
+
+	if (!priv->task)
+		return;
+
+	release_task_mempolicy(priv);
+	unlock_vma_range(&priv->lock_ctx);
+	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->lock_ctx.mm = proc_mem_open(inode, PTRACE_MODE_READ);
+	if (IS_ERR(priv->lock_ctx.mm)) {
+		int err = PTR_ERR(priv->lock_ctx.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->lock_ctx.mm)
+		mmdrop(priv->lock_ctx.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));
+}
+
+static void get_vma_name(struct vm_area_struct *vma,
+			 const struct path **path,
+			 const char **name,
+			 const char **name_fmt)
+{
+	struct anon_vma_name *anon_name = vma->vm_mm ? anon_vma_name(vma) : NULL;
+
+	*name = NULL;
+	*path = NULL;
+	*name_fmt = NULL;
+
+	/*
+	 * Print the dentry name for named mappings, and a
+	 * special [heap] marker for the heap:
+	 */
+	if (vma->vm_file) {
+		/*
+		 * If user named this anon shared memory via
+		 * prctl(PR_SET_VMA ..., use the provided name.
+		 */
+		if (anon_name) {
+			*name_fmt = "[anon_shmem:%s]";
+			*name = anon_name->name;
+		} else {
+			*path = file_user_path(vma->vm_file);
+		}
+		return;
+	}
+
+	if (vma->vm_ops && vma->vm_ops->name) {
+		*name = vma->vm_ops->name(vma);
+		if (*name)
+			return;
+	}
+
+	*name = arch_vma_name(vma);
+	if (*name)
+		return;
+
+	if (!vma->vm_mm) {
+		*name = "[vdso]";
+		return;
+	}
+
+	if (vma_is_initial_heap(vma)) {
+		*name = "[heap]";
+		return;
+	}
+
+	if (vma_is_initial_stack(vma)) {
+		*name = "[stack]";
+		return;
+	}
+
+	if (anon_name) {
+		*name_fmt = "[anon:%s]";
+		*name = anon_name->name;
+		return;
+	}
+}
+
+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, u64 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)
+{
+	const struct path *path;
+	const char *name_fmt, *name;
+	vm_flags_t flags = vma->vm_flags;
+	u64 ino = 0;
+	unsigned long long pgoff = 0;
+	unsigned long start, end;
+	dev_t dev = 0;
+
+	if (vma->vm_file) {
+		const struct inode *inode = file_user_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);
+
+	get_vma_name(vma, &path, &name, &name_fmt);
+	if (path) {
+		seq_pad(m, ' ');
+		seq_path(m, path, "\n");
+	} else if (name_fmt) {
+		seq_pad(m, ' ');
+		seq_printf(m, name_fmt, name);
+	} else 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);
+}
+
+#define PROCMAP_QUERY_VMA_FLAGS (				\
+		PROCMAP_QUERY_VMA_READABLE |			\
+		PROCMAP_QUERY_VMA_WRITABLE |			\
+		PROCMAP_QUERY_VMA_EXECUTABLE |			\
+		PROCMAP_QUERY_VMA_SHARED			\
+)
+
+#define PROCMAP_QUERY_VALID_FLAGS_MASK (			\
+		PROCMAP_QUERY_COVERING_OR_NEXT_VMA |		\
+		PROCMAP_QUERY_FILE_BACKED_VMA |			\
+		PROCMAP_QUERY_VMA_FLAGS				\
+)
+
+#ifdef CONFIG_PER_VMA_LOCK
+
+static int query_vma_setup(struct proc_maps_locking_ctx *lock_ctx)
+{
+	reset_lock_ctx(lock_ctx);
+
+	return 0;
+}
+
+static void query_vma_teardown(struct proc_maps_locking_ctx *lock_ctx)
+{
+	if (lock_ctx->mmap_locked)
+		unlock_ctx_mm(lock_ctx);
+	else
+		unlock_ctx_vma(lock_ctx);
+}
+
+static struct vm_area_struct *query_vma_find_by_addr(struct proc_maps_locking_ctx *lock_ctx,
+						     unsigned long addr)
+{
+	struct mm_struct *mm = lock_ctx->mm;
+	struct vm_area_struct *vma;
+	struct vma_iterator vmi;
+
+	if (lock_ctx->mmap_locked)
+		return find_vma(mm, addr);
+
+	/* Unlock previously locked VMA and find the next one under RCU */
+	unlock_ctx_vma(lock_ctx);
+	rcu_read_lock();
+	vma_iter_init(&vmi, mm, addr);
+	vma = lock_next_vma(mm, &vmi, addr);
+	rcu_read_unlock();
+
+	if (!vma)
+		return NULL;
+
+	if (!IS_ERR(vma)) {
+		lock_ctx->locked_vma = vma;
+		return vma;
+	}
+
+	if (PTR_ERR(vma) == -EAGAIN) {
+		/* Fallback to mmap_lock on vma->vm_refcnt overflow */
+		mmap_read_lock(mm);
+		vma = find_vma(mm, addr);
+		lock_ctx->mmap_locked = true;
+	}
+
+	return vma;
+}
+
+#else /* CONFIG_PER_VMA_LOCK */
+
+static int query_vma_setup(struct proc_maps_locking_ctx *lock_ctx)
+{
+	return mmap_read_lock_killable(lock_ctx->mm);
+}
+
+static void query_vma_teardown(struct proc_maps_locking_ctx *lock_ctx)
+{
+	mmap_read_unlock(lock_ctx->mm);
+}
+
+static struct vm_area_struct *query_vma_find_by_addr(struct proc_maps_locking_ctx *lock_ctx,
+						     unsigned long addr)
+{
+	return find_vma(lock_ctx->mm, addr);
+}
+
+#endif  /* CONFIG_PER_VMA_LOCK */
+
+static struct vm_area_struct *query_matching_vma(struct proc_maps_locking_ctx *lock_ctx,
+						 unsigned long addr, u32 flags)
+{
+	struct vm_area_struct *vma;
+
+next_vma:
+	vma = query_vma_find_by_addr(lock_ctx, addr);
+	if (IS_ERR(vma))
+		return vma;
+
+	if (!vma)
+		goto no_vma;
+
+	/* user requested only file-backed VMA, keep iterating */
+	if ((flags & PROCMAP_QUERY_FILE_BACKED_VMA) && !vma->vm_file)
+		goto skip_vma;
+
+	/* VMA permissions should satisfy query flags */
+	if (flags & PROCMAP_QUERY_VMA_FLAGS) {
+		u32 perm = 0;
+
+		if (flags & PROCMAP_QUERY_VMA_READABLE)
+			perm |= VM_READ;
+		if (flags & PROCMAP_QUERY_VMA_WRITABLE)
+			perm |= VM_WRITE;
+		if (flags & PROCMAP_QUERY_VMA_EXECUTABLE)
+			perm |= VM_EXEC;
+		if (flags & PROCMAP_QUERY_VMA_SHARED)
+			perm |= VM_MAYSHARE;
+
+		if ((vma->vm_flags & perm) != perm)
+			goto skip_vma;
+	}
+
+	/* found covering VMA or user is OK with the matching next VMA */
+	if ((flags & PROCMAP_QUERY_COVERING_OR_NEXT_VMA) || vma->vm_start <= addr)
+		return vma;
+
+skip_vma:
+	/*
+	 * If the user needs closest matching VMA, keep iterating.
+	 */
+	addr = vma->vm_end;
+	if (flags & PROCMAP_QUERY_COVERING_OR_NEXT_VMA)
+		goto next_vma;
+
+no_vma:
+	return ERR_PTR(-ENOENT);
+}
+
+static int do_procmap_query(struct mm_struct *mm, void __user *uarg)
+{
+	struct proc_maps_locking_ctx lock_ctx = { .mm = mm };
+	struct procmap_query karg;
+	struct vm_area_struct *vma;
+	struct file *vm_file = NULL;
+	const char *name = NULL;
+	char build_id_buf[BUILD_ID_SIZE_MAX], *name_buf = NULL;
+	__u64 usize;
+	int err;
+
+	if (copy_from_user(&usize, (void __user *)uarg, sizeof(usize)))
+		return -EFAULT;
+	/* argument struct can never be that large, reject abuse */
+	if (usize > PAGE_SIZE)
+		return -E2BIG;
+	/* argument struct should have at least query_flags and query_addr fields */
+	if (usize < offsetofend(struct procmap_query, query_addr))
+		return -EINVAL;
+	err = copy_struct_from_user(&karg, sizeof(karg), uarg, usize);
+	if (err)
+		return err;
+
+	/* reject unknown flags */
+	if (karg.query_flags & ~PROCMAP_QUERY_VALID_FLAGS_MASK)
+		return -EINVAL;
+	/* either both buffer address and size are set, or both should be zero */
+	if (!!karg.vma_name_size != !!karg.vma_name_addr)
+		return -EINVAL;
+	if (!!karg.build_id_size != !!karg.build_id_addr)
+		return -EINVAL;
+
+	if (!mm || !mmget_not_zero(mm))
+		return -ESRCH;
+
+	err = query_vma_setup(&lock_ctx);
+	if (err) {
+		mmput(mm);
+		return err;
+	}
+
+	vma = query_matching_vma(&lock_ctx, karg.query_addr, karg.query_flags);
+	if (IS_ERR(vma)) {
+		err = PTR_ERR(vma);
+		vma = NULL;
+		goto out;
+	}
+
+	karg.vma_start = vma->vm_start;
+	karg.vma_end = vma->vm_end;
+
+	karg.vma_flags = 0;
+	if (vma->vm_flags & VM_READ)
+		karg.vma_flags |= PROCMAP_QUERY_VMA_READABLE;
+	if (vma->vm_flags & VM_WRITE)
+		karg.vma_flags |= PROCMAP_QUERY_VMA_WRITABLE;
+	if (vma->vm_flags & VM_EXEC)
+		karg.vma_flags |= PROCMAP_QUERY_VMA_EXECUTABLE;
+	if (vma->vm_flags & VM_MAYSHARE)
+		karg.vma_flags |= PROCMAP_QUERY_VMA_SHARED;
+
+	karg.vma_page_size = vma_kernel_pagesize(vma);
+
+	if (vma->vm_file) {
+		const struct inode *inode = file_user_inode(vma->vm_file);
+
+		karg.vma_offset = ((__u64)vma->vm_pgoff) << PAGE_SHIFT;
+		karg.dev_major = MAJOR(inode->i_sb->s_dev);
+		karg.dev_minor = MINOR(inode->i_sb->s_dev);
+		karg.inode = inode->i_ino;
+	} else {
+		karg.vma_offset = 0;
+		karg.dev_major = 0;
+		karg.dev_minor = 0;
+		karg.inode = 0;
+	}
+
+	if (karg.vma_name_size) {
+		size_t name_buf_sz = min_t(size_t, PATH_MAX, karg.vma_name_size);
+		const struct path *path;
+		const char *name_fmt;
+		size_t name_sz = 0;
+
+		get_vma_name(vma, &path, &name, &name_fmt);
+
+		if (path || name_fmt || name) {
+			name_buf = kmalloc(name_buf_sz, GFP_KERNEL);
+			if (!name_buf) {
+				err = -ENOMEM;
+				goto out;
+			}
+		}
+		if (path) {
+			name = d_path(path, name_buf, name_buf_sz);
+			if (IS_ERR(name)) {
+				err = PTR_ERR(name);
+				goto out;
+			}
+			name_sz = name_buf + name_buf_sz - name;
+		} else if (name || name_fmt) {
+			name_sz = 1 + snprintf(name_buf, name_buf_sz, name_fmt ?: "%s", name);
+			name = name_buf;
+		}
+		if (name_sz > name_buf_sz) {
+			err = -ENAMETOOLONG;
+			goto out;
+		}
+		karg.vma_name_size = name_sz;
+	}
+
+	if (karg.build_id_size && vma->vm_file)
+		vm_file = get_file(vma->vm_file);
+
+	/* unlock vma or mmap_lock, and put mm_struct before copying data to user */
+	query_vma_teardown(&lock_ctx);
+	mmput(mm);
+
+	if (karg.build_id_size) {
+		__u32 build_id_sz;
+
+		if (vm_file)
+			err = build_id_parse_file(vm_file, build_id_buf, &build_id_sz);
+		else
+			err = -ENOENT;
+		if (err) {
+			karg.build_id_size = 0;
+		} else {
+			if (karg.build_id_size < build_id_sz) {
+				err = -ENAMETOOLONG;
+				goto out_file;
+			}
+			karg.build_id_size = build_id_sz;
+		}
+	}
+
+	if (vm_file)
+		fput(vm_file);
+
+	if (karg.vma_name_size && copy_to_user(u64_to_user_ptr(karg.vma_name_addr),
+					       name, karg.vma_name_size)) {
+		kfree(name_buf);
+		return -EFAULT;
+	}
+	kfree(name_buf);
+
+	if (karg.build_id_size && copy_to_user(u64_to_user_ptr(karg.build_id_addr),
+					       build_id_buf, karg.build_id_size))
+		return -EFAULT;
+
+	if (copy_to_user(uarg, &karg, min_t(size_t, sizeof(karg), usize)))
+		return -EFAULT;
+
+	return 0;
+
+out:
+	query_vma_teardown(&lock_ctx);
+	mmput(mm);
+out_file:
+	if (vm_file)
+		fput(vm_file);
+	kfree(name_buf);
+	return err;
+}
+
+static long procfs_procmap_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
+{
+	struct seq_file *seq = file->private_data;
+	struct proc_maps_private *priv = seq->private;
+
+	switch (cmd) {
+	case PROCMAP_QUERY:
+		/* priv->lock_ctx.mm is set during file open operation */
+		return do_procmap_query(priv->lock_ctx.mm, (void __user *)arg);
+	default:
+		return -ENOIOCTLCMD;
+	}
+}
+
+const struct file_operations proc_pid_maps_operations = {
+	.open		= pid_maps_open,
+	.read		= seq_read,
+	.llseek		= seq_lseek,
+	.release	= proc_map_release,
+	.unlocked_ioctl = procfs_procmap_ioctl,
+	.compat_ioctl	= compat_ptr_ioctl,
+};
+
+/*
+ * 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;
+	unsigned long ksm;
+	u64 pss;
+	u64 pss_anon;
+	u64 pss_file;
+	u64 pss_shmem;
+	u64 pss_dirty;
+	u64 pss_locked;
+	u64 swap_pss;
+};
+
+static void smaps_page_accumulate(struct mem_size_stats *mss,
+		struct folio *folio, unsigned long size, unsigned long pss,
+		bool dirty, bool locked, bool private)
+{
+	mss->pss += pss;
+
+	if (folio_test_anon(folio))
+		mss->pss_anon += pss;
+	else if (folio_test_swapbacked(folio))
+		mss->pss_shmem += pss;
+	else
+		mss->pss_file += pss;
+
+	if (locked)
+		mss->pss_locked += pss;
+
+	if (dirty || folio_test_dirty(folio)) {
+		mss->pss_dirty += pss;
+		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 present)
+{
+	struct folio *folio = page_folio(page);
+	int i, nr = compound ? compound_nr(page) : 1;
+	unsigned long size = nr * PAGE_SIZE;
+	bool exclusive;
+	int mapcount;
+
+	/*
+	 * First accumulate quantities that depend only on |size| and the type
+	 * of the compound page.
+	 */
+	if (folio_test_anon(folio)) {
+		mss->anonymous += size;
+		if (!folio_test_swapbacked(folio) && !dirty &&
+		    !folio_test_dirty(folio))
+			mss->lazyfree += size;
+	}
+
+	if (folio_test_ksm(folio))
+		mss->ksm += size;
+
+	mss->resident += size;
+	/* Accumulate the size in pages that have been accessed. */
+	if (young || folio_test_young(folio) || folio_test_referenced(folio))
+		mss->referenced += size;
+
+	/*
+	 * Then accumulate quantities that may depend on sharing, or that may
+	 * differ page-by-page.
+	 *
+	 * refcount == 1 for present entries guarantees that the folio is mapped
+	 * exactly once. For large folios this implies that exactly one
+	 * PTE/PMD/... maps (a part of) this folio.
+	 *
+	 * Treat all non-present entries (where relying on the mapcount and
+	 * refcount doesn't make sense) as "maybe shared, but not sure how
+	 * often". We treat device private entries as being fake-present.
+	 *
+	 * Note that it would not be safe to read the mapcount especially for
+	 * pages referenced by migration entries, even with the PTL held.
+	 */
+	if (folio_ref_count(folio) == 1 || !present) {
+		smaps_page_accumulate(mss, folio, size, size << PSS_SHIFT,
+				      dirty, locked, present);
+		return;
+	}
+
+	if (IS_ENABLED(CONFIG_NO_PAGE_MAPCOUNT)) {
+		mapcount = folio_average_page_mapcount(folio);
+		exclusive = !folio_maybe_mapped_shared(folio);
+	}
+
+	/*
+	 * We obtain a snapshot of the mapcount. Without holding the folio lock
+	 * this snapshot can be slightly wrong as we cannot always read the
+	 * mapcount atomically.
+	 */
+	for (i = 0; i < nr; i++, page++) {
+		unsigned long pss = PAGE_SIZE << PSS_SHIFT;
+
+		if (IS_ENABLED(CONFIG_PAGE_MAPCOUNT)) {
+			mapcount = folio_precise_page_mapcount(folio, page);
+			exclusive = mapcount < 2;
+		}
+
+		if (mapcount >= 2)
+			pss /= mapcount;
+		smaps_page_accumulate(mss, folio, PAGE_SIZE, pss,
+				dirty, locked, exclusive);
+	}
+}
+
+#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;
+	struct vm_area_struct *vma = walk->vma;
+
+	mss->swap += shmem_partial_swap_usage(walk->vma->vm_file->f_mapping,
+					      linear_page_index(vma, addr),
+					      linear_page_index(vma, end));
+
+	return 0;
+}
+#else
+#define smaps_pte_hole		NULL
+#endif /* CONFIG_SHMEM */
+
+static void smaps_pte_hole_lookup(unsigned long addr, struct mm_walk *walk)
+{
+#ifdef CONFIG_SHMEM
+	if (walk->ops->pte_hole) {
+		/* depth is not used */
+		smaps_pte_hole(addr, addr + PAGE_SIZE, 0, walk);
+	}
+#endif
+}
+
+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 present = false, young = false, dirty = false;
+	pte_t ptent = ptep_get(pte);
+
+	if (pte_present(ptent)) {
+		page = vm_normal_page(vma, addr, ptent);
+		young = pte_young(ptent);
+		dirty = pte_dirty(ptent);
+		present = true;
+	} else if (pte_none(ptent)) {
+		smaps_pte_hole_lookup(addr, walk);
+	} else {
+		const softleaf_t entry = softleaf_from_pte(ptent);
+
+		if (softleaf_is_swap(entry)) {
+			int mapcount;
+
+			mss->swap += PAGE_SIZE;
+			mapcount = swp_swapcount(entry);
+			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 (softleaf_has_pfn(entry)) {
+			if (softleaf_is_device_private(entry))
+				present = true;
+			page = softleaf_to_page(entry);
+		}
+	}
+
+	if (!page)
+		return;
+
+	smaps_account(mss, page, false, young, dirty, locked, present);
+}
+
+#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 present = false;
+	struct folio *folio;
+
+	if (pmd_none(*pmd))
+		return;
+	if (pmd_present(*pmd)) {
+		page = vm_normal_page_pmd(vma, addr, *pmd);
+		present = true;
+	} else if (unlikely(thp_migration_supported())) {
+		const softleaf_t entry = softleaf_from_pmd(*pmd);
+
+		if (softleaf_has_pfn(entry))
+			page = softleaf_to_page(entry);
+	}
+	if (IS_ERR_OR_NULL(page))
+		return;
+	folio = page_folio(page);
+	if (folio_test_anon(folio))
+		mss->anonymous_thp += HPAGE_PMD_SIZE;
+	else if (folio_test_swapbacked(folio))
+		mss->shmem_thp += HPAGE_PMD_SIZE;
+	else if (folio_is_zone_device(folio))
+		/* pass */;
+	else
+		mss->file_thp += HPAGE_PMD_SIZE;
+
+	smaps_account(mss, page, true, pmd_young(*pmd), pmd_dirty(*pmd),
+		      locked, present);
+}
+#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;
+	}
+
+	pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl);
+	if (!pte) {
+		walk->action = ACTION_AGAIN;
+		return 0;
+	}
+	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.
+	 *
+	 * The length of the second argument of mnemonics[]
+	 * needs to be 3 instead of previously set 2
+	 * (i.e. from [BITS_PER_LONG][2] to [BITS_PER_LONG][3])
+	 * to avoid spurious
+	 * -Werror=unterminated-string-initialization warning
+	 *  with GCC 15
+	 */
+	static const char mnemonics[BITS_PER_LONG][3] = {
+		/*
+		 * 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_MAYBE_GUARD)]	= "gu",
+		[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_LOCKONFAULT)]	= "lf",
+		[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)]	= "",
+#if CONFIG_ARCH_PKEY_BITS > 3
+		[ilog2(VM_PKEY_BIT3)]	= "",
+#endif
+#if CONFIG_ARCH_PKEY_BITS > 4
+		[ilog2(VM_PKEY_BIT4)]	= "",
+#endif
+#endif /* CONFIG_ARCH_HAS_PKEYS */
+#ifdef CONFIG_HAVE_ARCH_USERFAULTFD_MINOR
+		[ilog2(VM_UFFD_MINOR)]	= "ui",
+#endif /* CONFIG_HAVE_ARCH_USERFAULTFD_MINOR */
+#ifdef CONFIG_USERFAULTFD_RWP
+		[ilog2(VM_UFFD_RWP)]	= "ur",
+#endif
+#ifdef CONFIG_ARCH_HAS_USER_SHADOW_STACK
+		[ilog2(VM_SHADOW_STACK)] = "ss",
+#endif
+#if defined(CONFIG_64BIT) || defined(CONFIG_PPC32)
+		[ilog2(VM_DROPPABLE)] = "dp",
+#endif
+#ifdef CONFIG_64BIT
+		[ilog2(VM_SEALED)] = "sl",
+#endif
+	};
+	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_printf(m, "%s ", mnemonics[i]);
+	}
+	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 folio *folio = NULL;
+	bool present = false;
+	spinlock_t *ptl;
+	pte_t ptent;
+
+	ptl = huge_pte_lock(hstate_vma(vma), walk->mm, pte);
+	ptent = huge_ptep_get(walk->mm, addr, pte);
+	if (pte_present(ptent)) {
+		folio = page_folio(pte_page(ptent));
+		present = true;
+	} else {
+		const softleaf_t entry = softleaf_from_pte(ptent);
+
+		if (softleaf_has_pfn(entry))
+			folio = softleaf_to_folio(entry);
+	}
+
+	if (folio) {
+		/* We treat non-present entries as "maybe shared". */
+		if (!present || folio_maybe_mapped_shared(folio) ||
+		    hugetlb_pmd_shared(pte))
+			mss->shared_hugetlb += huge_page_size(hstate_vma(vma));
+		else
+			mss->private_hugetlb += huge_page_size(hstate_vma(vma));
+	}
+	spin_unlock(ptl);
+	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,
+	.walk_lock		= PGWALK_RDLOCK,
+};
+
+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,
+	.walk_lock		= PGWALK_RDLOCK,
+};
+
+#ifdef CONFIG_PER_VMA_LOCK
+
+static const struct mm_walk_ops smaps_walk_vma_lock_ops = {
+	.pmd_entry		= smaps_pte_range,
+	.hugetlb_entry		= smaps_hugetlb_range,
+	.walk_lock		= PGWALK_VMA_RDLOCK_VERIFY,
+};
+
+static const struct mm_walk_ops smaps_shmem_walk_vma_lock_ops = {
+	.pmd_entry		= smaps_pte_range,
+	.hugetlb_entry		= smaps_hugetlb_range,
+	.pte_hole		= smaps_pte_hole,
+	.walk_lock		= PGWALK_VMA_RDLOCK_VERIFY,
+};
+
+static inline const struct mm_walk_ops *
+get_smaps_walk_ops(struct proc_maps_private *priv)
+{
+	if (priv->lock_ctx.mmap_locked)
+		return &smaps_walk_ops;
+	return &smaps_walk_vma_lock_ops;
+}
+
+static inline const struct mm_walk_ops *
+get_smaps_shmem_walk_ops(struct proc_maps_private *priv)
+{
+	if (priv->lock_ctx.mmap_locked)
+		return  &smaps_shmem_walk_ops;
+	return &smaps_shmem_walk_vma_lock_ops;
+}
+
+#else /* CONFIG_PER_VMA_LOCK */
+
+static inline const struct mm_walk_ops *
+get_smaps_walk_ops(struct proc_maps_private *priv)
+{
+	return &smaps_walk_ops;
+}
+
+static inline const struct mm_walk_ops *
+get_smaps_shmem_walk_ops(struct proc_maps_private *priv)
+{
+	return &smaps_shmem_walk_ops;
+}
+
+#endif /* CONFIG_PER_VMA_LOCK */
+
+/*
+ * 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 proc_maps_private *priv,
+			      struct vm_area_struct *vma,
+			      struct mem_size_stats *mss, unsigned long start)
+{
+	const struct mm_walk_ops *ops = get_smaps_walk_ops(priv);
+
+	/* Invalid start */
+	if (start >= vma->vm_end)
+		return;
+
+	if (vma == get_gate_vma(priv->lock_ctx.mm))
+		return;
+
+	/* Might sleep. Drop RCU read lock but keep the VMA locked. */
+	drop_rcu(priv);
+
+	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 {
+			ops = get_smaps_shmem_walk_ops(priv);
+		}
+	}
+
+	if (!start)
+		walk_page_vma(vma, ops, mss);
+	else
+		walk_page_range(vma->vm_mm, start, vma->vm_end, ops, mss);
+
+	reacquire_rcu(priv);
+}
+
+#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);
+	SEQ_PUT_DEC(" kB\nPss_Dirty:      ", mss->pss_dirty >> 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\nKSM:            ", mss->ksm);
+	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 proc_maps_private *priv = m->private;
+	struct vm_area_struct *vma = v;
+	struct mem_size_stats mss = {};
+
+	smap_gather_stats(priv, 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:    %8u\n",
+		   !!thp_vma_allowable_orders(vma, vma->vm_flags, TVA_SMAPS,
+					      THP_ORDERS_ALL));
+
+	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 = priv->lock_ctx.mm;
+	struct vm_area_struct *vma;
+	unsigned long vma_start = 0, last_vma_end = 0;
+	int ret = 0;
+	VMA_ITERATOR(vmi, mm, 0);
+
+	priv->task = get_proc_task(priv->inode);
+	if (!priv->task)
+		return -ESRCH;
+
+	if (!mm || !mmget_not_zero(mm)) {
+		ret = -ESRCH;
+		goto out_put_task;
+	}
+
+	ret = lock_ctx_mm(&priv->lock_ctx);
+	if (ret)
+		goto out_put_mm;
+
+	hold_task_mempolicy(priv);
+	vma = vma_next(&vmi);
+
+	if (unlikely(!vma))
+		goto empty_set;
+
+	vma_start = vma->vm_start;
+	do {
+		smap_gather_stats(priv, 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)) {
+			vma_iter_invalidate(&vmi);
+			unlock_ctx_mm(&priv->lock_ctx);
+			ret = lock_ctx_mm(&priv->lock_ctx);
+			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:
+			 *
+			 *    vma_next(vmi) will return VMA3.
+			 *    In this case, just continue from VMA3.
+			 *
+			 * 2) VMA2 still exists:
+			 *
+			 *    vma_next(vmi) will return VMA3.
+			 *    In this case, just continue from VMA3.
+			 *
+			 * 3) No more VMAs can be found:
+			 *
+			 *    vma_next(vmi) will return NULL.
+			 *    No more things to do, just break.
+			 *
+			 * 4) (last_vma_end - 1) is the middle of a vma (VMA'):
+			 *
+			 *    vma_next(vmi) will return VMA' whose range
+			 *    contains last_vma_end.
+			 *    Iterate VMA' from last_vma_end.
+			 */
+			vma = vma_next(&vmi);
+			/* Case 3 above */
+			if (!vma)
+				break;
+
+			/* Case 1 and 2 above */
+			if (vma->vm_start >= last_vma_end) {
+				smap_gather_stats(priv, vma, &mss, 0);
+				last_vma_end = vma->vm_end;
+				continue;
+			}
+
+			/* Case 4 above */
+			if (vma->vm_end > last_vma_end) {
+				smap_gather_stats(priv, vma, &mss, last_vma_end);
+				last_vma_end = vma->vm_end;
+			}
+		}
+	} for_each_vma(vmi, vma);
+
+empty_set:
+	show_vma_header_prefix(m, vma_start, last_vma_end, 0, 0, 0, 0);
+	seq_pad(m, ' ');
+	seq_puts(m, "[rollup]\n");
+
+	__show_smap(m, &mss, true);
+
+	release_task_mempolicy(priv);
+	unlock_ctx_mm(&priv->lock_ctx);
+
+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_obj(*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->lock_ctx.mm = proc_mem_open(inode, PTRACE_MODE_READ);
+	if (IS_ERR_OR_NULL(priv->lock_ctx.mm)) {
+		ret = priv->lock_ctx.mm ? PTR_ERR(priv->lock_ctx.mm) : -ESRCH;
+
+		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->lock_ctx.mm)
+		mmdrop(priv->lock_ctx.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;
+};
+
+static inline bool pte_is_pinned(struct vm_area_struct *vma, unsigned long addr, pte_t pte)
+{
+	struct folio *folio;
+
+	if (!pte_write(pte))
+		return false;
+	if (!vma_is_cow_mapping(vma))
+		return false;
+	if (likely(!mm_flags_test(MMF_HAS_PINNED, vma->vm_mm)))
+		return false;
+	folio = vm_normal_folio(vma, addr, pte);
+	if (!folio)
+		return false;
+	return folio_maybe_dma_pinned(folio);
+}
+
+static inline void clear_soft_dirty(struct vm_area_struct *vma,
+		unsigned long addr, pte_t *pte)
+{
+	if (!pgtable_supports_soft_dirty())
+		return;
+	/*
+	 * 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 = ptep_get(pte);
+
+	if (pte_none(ptent))
+		return;
+
+	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 {
+		ptent = pte_swp_clear_soft_dirty(ptent);
+		set_pte_at(vma->vm_mm, addr, pte, ptent);
+	}
+}
+
+#if 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 (!pgtable_supports_soft_dirty())
+		return;
+
+	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 (pmd_is_migration_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 folio *folio;
+
+	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;
+
+		folio = pmd_folio(*pmd);
+
+		/* Clear accessed and referenced bits. */
+		pmdp_test_and_clear_young(vma, addr, pmd);
+		folio_test_clear_young(folio);
+		folio_clear_referenced(folio);
+out:
+		spin_unlock(ptl);
+		return 0;
+	}
+
+	pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl);
+	if (!pte) {
+		walk->action = ACTION_AGAIN;
+		return 0;
+	}
+	for (; addr != end; pte++, addr += PAGE_SIZE) {
+		ptent = ptep_get(pte);
+
+		if (cp->type == CLEAR_REFS_SOFT_DIRTY) {
+			clear_soft_dirty(vma, addr, pte);
+			continue;
+		}
+
+		if (!pte_present(ptent))
+			continue;
+
+		folio = vm_normal_folio(vma, addr, ptent);
+		if (!folio)
+			continue;
+
+		/* Clear accessed and referenced bits. */
+		ptep_test_and_clear_young(vma, addr, pte);
+		folio_test_clear_young(folio);
+		folio_clear_referenced(folio);
+	}
+	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,
+	.walk_lock		= PGWALK_WRLOCK,
+};
+
+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;
+
+	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) {
+		VMA_ITERATOR(vmi, mm, 0);
+		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_each_vma(vmi, vma) {
+				if (!(vma->vm_flags & VM_SOFTDIRTY))
+					continue;
+				vm_flags_clear(vma, VM_SOFTDIRTY);
+				vma_set_page_prot(vma);
+			}
+
+			inc_tlb_flush_pending(mm);
+			mmu_notifier_range_init(&range, MMU_NOTIFY_SOFT_DIRTY,
+						0, mm, 0, -1UL);
+			mmu_notifier_invalidate_range_start(&range);
+		}
+		walk_page_range(mm, 0, -1, &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_UFFD_WP		BIT_ULL(57)
+#define PM_GUARD_REGION		BIT_ULL(58)
+#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(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 bool __folio_page_mapped_exclusively(struct folio *folio, struct page *page)
+{
+	if (IS_ENABLED(CONFIG_PAGE_MAPCOUNT))
+		return folio_precise_page_mapcount(folio, page) == 1;
+	return !folio_maybe_mapped_shared(folio);
+}
+
+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(&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(&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;
+	struct folio *folio;
+
+	if (pte_none(pte))
+		goto out;
+
+	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;
+		if (pte_uffd(pte))
+			flags |= PM_UFFD_WP;
+	} else {
+		softleaf_t entry;
+
+		if (pte_swp_soft_dirty(pte))
+			flags |= PM_SOFT_DIRTY;
+		if (pte_swp_uffd(pte))
+			flags |= PM_UFFD_WP;
+		entry = softleaf_from_pte(pte);
+		if (pm->show_pfn) {
+			pgoff_t offset;
+
+			/*
+			 * For PFN swap offsets, keeping the offset field
+			 * to be PFN only to be compatible with old smaps.
+			 */
+			if (softleaf_has_pfn(entry))
+				offset = softleaf_to_pfn(entry);
+			else
+				offset = swp_offset(entry);
+			frame = swp_type(entry) |
+			    (offset << MAX_SWAPFILES_SHIFT);
+		}
+		flags |= PM_SWAP;
+		if (softleaf_has_pfn(entry))
+			page = softleaf_to_page(entry);
+		if (softleaf_is_uffd_wp_marker(entry))
+			flags |= PM_UFFD_WP;
+		if (softleaf_is_guard_marker(entry))
+			flags |=  PM_GUARD_REGION;
+	}
+
+	if (page) {
+		folio = page_folio(page);
+		if (!folio_test_anon(folio))
+			flags |= PM_FILE;
+		if ((flags & PM_PRESENT) &&
+		    __folio_page_mapped_exclusively(folio, page))
+			flags |= PM_MMAP_EXCLUSIVE;
+	}
+
+out:
+	if (vma->vm_flags & VM_SOFTDIRTY)
+		flags |= PM_SOFT_DIRTY;
+
+	return make_pme(frame, flags);
+}
+
+#ifdef CONFIG_TRANSPARENT_HUGEPAGE
+static int pagemap_pmd_range_thp(pmd_t *pmdp, unsigned long addr,
+		unsigned long end, struct vm_area_struct *vma,
+		struct pagemapread *pm)
+{
+	unsigned int idx = (addr & ~PMD_MASK) >> PAGE_SHIFT;
+	u64 flags = 0, frame = 0;
+	pmd_t pmd = *pmdp;
+	struct page *page = NULL;
+	struct folio *folio = NULL;
+	int err = 0;
+
+	if (vma->vm_flags & VM_SOFTDIRTY)
+		flags |= PM_SOFT_DIRTY;
+
+	if (pmd_none(pmd))
+		goto populate_pagemap;
+
+	if (pmd_present(pmd)) {
+		page = pmd_page(pmd);
+
+		flags |= PM_PRESENT;
+		if (pmd_soft_dirty(pmd))
+			flags |= PM_SOFT_DIRTY;
+		if (pmd_uffd(pmd))
+			flags |= PM_UFFD_WP;
+		if (pm->show_pfn)
+			frame = pmd_pfn(pmd) + idx;
+	} else if (thp_migration_supported()) {
+		const softleaf_t entry = softleaf_from_pmd(pmd);
+		unsigned long offset;
+
+		if (pm->show_pfn) {
+			if (softleaf_has_pfn(entry))
+				offset = softleaf_to_pfn(entry) + idx;
+			else
+				offset = swp_offset(entry) + idx;
+			frame = swp_type(entry) |
+				(offset << MAX_SWAPFILES_SHIFT);
+		}
+		flags |= PM_SWAP;
+		if (pmd_swp_soft_dirty(pmd))
+			flags |= PM_SOFT_DIRTY;
+		if (pmd_swp_uffd(pmd))
+			flags |= PM_UFFD_WP;
+		if (softleaf_has_pfn(entry))
+			page = softleaf_to_page(entry);
+	}
+
+	if (page) {
+		folio = page_folio(page);
+		if (!folio_test_anon(folio))
+			flags |= PM_FILE;
+	}
+
+populate_pagemap:
+	for (; addr != end; addr += PAGE_SIZE, idx++) {
+		u64 cur_flags = flags;
+		pagemap_entry_t pme;
+
+		if (folio && (flags & PM_PRESENT) &&
+		    __folio_page_mapped_exclusively(folio, page))
+			cur_flags |= PM_MMAP_EXCLUSIVE;
+
+		pme = make_pme(frame, cur_flags);
+		err = add_to_pagemap(&pme, pm);
+		if (err)
+			break;
+		if (pm->show_pfn) {
+			if (flags & PM_PRESENT)
+				frame++;
+			else if (flags & PM_SWAP)
+				frame += (1 << MAX_SWAPFILES_SHIFT);
+		}
+	}
+	return err;
+}
+#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
+
+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
+	ptl = pmd_trans_huge_lock(pmdp, vma);
+	if (ptl) {
+		err = pagemap_pmd_range_thp(pmdp, addr, end, vma, pm);
+		spin_unlock(ptl);
+		return err;
+	}
+#endif
+
+	/*
+	 * 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);
+	if (!pte) {
+		walk->action = ACTION_AGAIN;
+		return err;
+	}
+	for (; addr < end; pte++, addr += PAGE_SIZE) {
+		pagemap_entry_t pme;
+
+		pme = pte_to_pagemap_entry(pm, vma, addr, ptep_get(pte));
+		err = add_to_pagemap(&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;
+	spinlock_t *ptl;
+	int err = 0;
+	pte_t pte;
+
+	if (vma->vm_flags & VM_SOFTDIRTY)
+		flags |= PM_SOFT_DIRTY;
+
+	ptl = huge_pte_lock(hstate_vma(vma), walk->mm, ptep);
+	pte = huge_ptep_get(walk->mm, addr, ptep);
+	if (pte_present(pte)) {
+		struct folio *folio = page_folio(pte_page(pte));
+
+		if (!folio_test_anon(folio))
+			flags |= PM_FILE;
+
+		if (!folio_maybe_mapped_shared(folio) &&
+		    !hugetlb_pmd_shared(ptep))
+			flags |= PM_MMAP_EXCLUSIVE;
+
+		if (huge_pte_uffd(pte))
+			flags |= PM_UFFD_WP;
+
+		flags |= PM_PRESENT;
+		if (pm->show_pfn)
+			frame = pte_pfn(pte) +
+				((addr & ~hmask) >> PAGE_SHIFT);
+	} else if (pte_swp_uffd_any(pte)) {
+		flags |= PM_UFFD_WP;
+	}
+
+	for (; addr != end; addr += PAGE_SIZE) {
+		pagemap_entry_t pme = make_pme(frame, flags);
+
+		err = add_to_pagemap(&pme, pm);
+		if (err)
+			break;
+		if (pm->show_pfn && (flags & PM_PRESENT))
+			frame++;
+	}
+
+	spin_unlock(ptl);
+	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,
+	.walk_lock	= PGWALK_RDLOCK,
+};
+
+/*
+ * /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
+ * Bit  57    pte is tracked by userfaultfd (uffd-wp or RWP)
+ * Bit  58    pte is a guard region
+ * Bits 59-60 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)) {
+		unsigned long end;
+
+		ret = mmap_read_lock_killable(mm);
+		if (ret)
+			goto out_free;
+		start_vaddr = untagged_addr_remote(mm, svpfn << PAGE_SHIFT);
+		mmap_read_unlock(mm);
+
+		end = start_vaddr + ((count / PM_ENTRY_BYTES) << PAGE_SHIFT);
+		if (end >= start_vaddr && end < mm->task_size)
+			end_vaddr = end;
+	}
+
+	/* Ensure the address is inside the task */
+	if (start_vaddr > mm->task_size)
+		start_vaddr = end_vaddr;
+
+	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_OR_NULL(mm))
+		return mm ? PTR_ERR(mm) : -ESRCH;
+	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;
+}
+
+#define PM_SCAN_CATEGORIES	(PAGE_IS_WPALLOWED | PAGE_IS_WRITTEN |	\
+				 PAGE_IS_FILE |	PAGE_IS_PRESENT |	\
+				 PAGE_IS_SWAPPED | PAGE_IS_PFNZERO |	\
+				 PAGE_IS_HUGE | PAGE_IS_SOFT_DIRTY |	\
+				 PAGE_IS_GUARD | PAGE_IS_ACCESSED)
+#define PM_SCAN_FLAGS		(PM_SCAN_WP_MATCHING | PM_SCAN_CHECK_WPASYNC)
+
+struct pagemap_scan_private {
+	struct pm_scan_arg arg;
+	unsigned long masks_of_interest, cur_vma_category;
+	struct page_region *vec_buf;
+	unsigned long vec_buf_len, vec_buf_index, found_pages;
+	struct page_region __user *vec_out;
+};
+
+static unsigned long pagemap_page_category(struct pagemap_scan_private *p,
+					   struct vm_area_struct *vma,
+					   unsigned long addr, pte_t pte)
+{
+	unsigned long categories;
+
+	if (pte_none(pte)) {
+		/*
+		 * An unpopulated pte carries no uffd bit, i.e. it is not
+		 * write-protected. The PAGE_IS_WRITTEN fast path in
+		 * pagemap_scan_pmd_entry() is now gated on a VM_UFFD_WP VMA;
+		 * gate the pte_none report here the same way so the two paths
+		 * still agree. RWP has no such fast path and an unpopulated
+		 * page is not part of the RWP working set, so it is reported as
+		 * neither.
+		 */
+		if (userfaultfd_wp(vma))
+			return PAGE_IS_WRITTEN;
+		return 0;
+	}
+
+	if (pte_present(pte)) {
+		struct page *page;
+
+		categories = PAGE_IS_PRESENT;
+
+		if (!pte_uffd(pte)) {
+			if (userfaultfd_wp(vma))
+				categories |= PAGE_IS_WRITTEN;
+			if (userfaultfd_rwp(vma))
+				categories |= PAGE_IS_ACCESSED;
+		}
+
+		if (p->masks_of_interest & PAGE_IS_FILE) {
+			page = vm_normal_page(vma, addr, pte);
+			if (page && !PageAnon(page))
+				categories |= PAGE_IS_FILE;
+		}
+
+		if (is_zero_pfn(pte_pfn(pte)))
+			categories |= PAGE_IS_PFNZERO;
+		if (pte_soft_dirty(pte))
+			categories |= PAGE_IS_SOFT_DIRTY;
+	} else {
+		softleaf_t entry;
+
+		categories = PAGE_IS_SWAPPED;
+
+		if (!pte_swp_uffd_any(pte)) {
+			if (userfaultfd_wp(vma))
+				categories |= PAGE_IS_WRITTEN;
+			if (userfaultfd_rwp(vma))
+				categories |= PAGE_IS_ACCESSED;
+		}
+
+		entry = softleaf_from_pte(pte);
+		if (softleaf_is_guard_marker(entry))
+			categories |= PAGE_IS_GUARD;
+		else if ((p->masks_of_interest & PAGE_IS_FILE) &&
+			 softleaf_has_pfn(entry) &&
+			 !folio_test_anon(softleaf_to_folio(entry)))
+			categories |= PAGE_IS_FILE;
+
+		if (pte_swp_soft_dirty(pte))
+			categories |= PAGE_IS_SOFT_DIRTY;
+	}
+
+	return categories;
+}
+
+static void make_uffd_wp_pte(struct vm_area_struct *vma,
+			     unsigned long addr, pte_t *pte, pte_t ptent)
+{
+	if (pte_present(ptent)) {
+		pte_t old_pte;
+
+		old_pte = ptep_modify_prot_start(vma, addr, pte);
+		ptent = pte_mkuffd(old_pte);
+		ptep_modify_prot_commit(vma, addr, pte, old_pte, ptent);
+	} else if (pte_none(ptent)) {
+		set_pte_at(vma->vm_mm, addr, pte,
+			   make_pte_marker(PTE_MARKER_UFFD_WP));
+	} else {
+		ptent = pte_swp_mkuffd(ptent);
+		set_pte_at(vma->vm_mm, addr, pte, ptent);
+	}
+}
+
+#ifdef CONFIG_TRANSPARENT_HUGEPAGE
+static unsigned long pagemap_thp_category(struct pagemap_scan_private *p,
+					  struct vm_area_struct *vma,
+					  unsigned long addr, pmd_t pmd)
+{
+	unsigned long categories = PAGE_IS_HUGE;
+
+	if (pmd_none(pmd))
+		return categories;
+
+	if (pmd_present(pmd)) {
+		struct page *page;
+
+		categories |= PAGE_IS_PRESENT;
+		if (!pmd_uffd(pmd)) {
+			if (userfaultfd_wp(vma))
+				categories |= PAGE_IS_WRITTEN;
+			if (userfaultfd_rwp(vma))
+				categories |= PAGE_IS_ACCESSED;
+		}
+
+		if (p->masks_of_interest & PAGE_IS_FILE) {
+			page = vm_normal_page_pmd(vma, addr, pmd);
+			if (page && !PageAnon(page))
+				categories |= PAGE_IS_FILE;
+		}
+
+		if (is_huge_zero_pmd(pmd))
+			categories |= PAGE_IS_PFNZERO;
+		if (pmd_soft_dirty(pmd))
+			categories |= PAGE_IS_SOFT_DIRTY;
+	} else {
+		categories |= PAGE_IS_SWAPPED;
+		if (!pmd_swp_uffd(pmd)) {
+			if (userfaultfd_wp(vma))
+				categories |= PAGE_IS_WRITTEN;
+			if (userfaultfd_rwp(vma))
+				categories |= PAGE_IS_ACCESSED;
+		}
+		if (pmd_swp_soft_dirty(pmd))
+			categories |= PAGE_IS_SOFT_DIRTY;
+
+		if (p->masks_of_interest & PAGE_IS_FILE) {
+			const softleaf_t entry = softleaf_from_pmd(pmd);
+
+			if (softleaf_has_pfn(entry) &&
+			    !folio_test_anon(softleaf_to_folio(entry)))
+				categories |= PAGE_IS_FILE;
+		}
+	}
+
+	return categories;
+}
+
+static void make_uffd_wp_pmd(struct vm_area_struct *vma,
+			     unsigned long addr, pmd_t *pmdp)
+{
+	pmd_t old, pmd = *pmdp;
+
+	if (pmd_present(pmd)) {
+		old = pmdp_invalidate_ad(vma, addr, pmdp);
+		pmd = pmd_mkuffd(old);
+		set_pmd_at(vma->vm_mm, addr, pmdp, pmd);
+	} else if (pmd_is_migration_entry(pmd)) {
+		pmd = pmd_swp_mkuffd(pmd);
+		set_pmd_at(vma->vm_mm, addr, pmdp, pmd);
+	}
+}
+#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
+
+#ifdef CONFIG_HUGETLB_PAGE
+static unsigned long pagemap_hugetlb_category(struct vm_area_struct *vma,
+					      pte_t pte)
+{
+	unsigned long categories = PAGE_IS_HUGE;
+
+	if (pte_none(pte))
+		return categories;
+
+	/*
+	 * According to pagemap_hugetlb_range(), file-backed HugeTLB
+	 * page cannot be swapped. So PAGE_IS_FILE is not checked for
+	 * swapped pages.
+	 */
+	if (pte_present(pte)) {
+		categories |= PAGE_IS_PRESENT;
+
+		if (!huge_pte_uffd(pte)) {
+			if (userfaultfd_wp(vma))
+				categories |= PAGE_IS_WRITTEN;
+			if (userfaultfd_rwp(vma))
+				categories |= PAGE_IS_ACCESSED;
+		}
+		if (!PageAnon(pte_page(pte)))
+			categories |= PAGE_IS_FILE;
+		if (is_zero_pfn(pte_pfn(pte)))
+			categories |= PAGE_IS_PFNZERO;
+		if (pte_soft_dirty(pte))
+			categories |= PAGE_IS_SOFT_DIRTY;
+	} else {
+		categories |= PAGE_IS_SWAPPED;
+
+		if (!pte_swp_uffd_any(pte)) {
+			if (userfaultfd_wp(vma))
+				categories |= PAGE_IS_WRITTEN;
+			if (userfaultfd_rwp(vma))
+				categories |= PAGE_IS_ACCESSED;
+		}
+		if (pte_swp_soft_dirty(pte))
+			categories |= PAGE_IS_SOFT_DIRTY;
+	}
+
+	return categories;
+}
+
+static void make_uffd_wp_huge_pte(struct vm_area_struct *vma,
+				  unsigned long addr, pte_t *ptep,
+				  pte_t ptent)
+{
+	const unsigned long psize = huge_page_size(hstate_vma(vma));
+	softleaf_t entry;
+
+	if (huge_pte_none(ptent)) {
+		set_huge_pte_at(vma->vm_mm, addr, ptep,
+				make_pte_marker(PTE_MARKER_UFFD_WP), psize);
+		return;
+	}
+
+	entry = softleaf_from_pte(ptent);
+	if (softleaf_is_hwpoison(entry) || softleaf_is_marker(entry))
+		return;
+
+	if (softleaf_is_migration(entry)) {
+		set_huge_pte_at(vma->vm_mm, addr, ptep,
+				pte_swp_mkuffd(ptent), psize);
+	} else {
+		pte_t old_pte, new_pte;
+
+		old_pte = huge_ptep_modify_prot_start(vma, addr, ptep);
+		new_pte = huge_pte_mkuffd(old_pte);
+		huge_ptep_modify_prot_commit(vma, addr, ptep, old_pte, new_pte);
+	}
+}
+#endif /* CONFIG_HUGETLB_PAGE */
+
+#if defined(CONFIG_TRANSPARENT_HUGEPAGE) || defined(CONFIG_HUGETLB_PAGE)
+static void pagemap_scan_backout_range(struct pagemap_scan_private *p,
+				       unsigned long addr, unsigned long end)
+{
+	struct page_region *cur_buf = &p->vec_buf[p->vec_buf_index];
+
+	if (!p->vec_buf)
+		return;
+
+	if (cur_buf->start != addr)
+		cur_buf->end = addr;
+	else
+		cur_buf->start = cur_buf->end = 0;
+
+	p->found_pages -= (end - addr) / PAGE_SIZE;
+}
+#endif
+
+static bool pagemap_scan_is_interesting_page(unsigned long categories,
+					     const struct pagemap_scan_private *p)
+{
+	categories ^= p->arg.category_inverted;
+	if ((categories & p->arg.category_mask) != p->arg.category_mask)
+		return false;
+	if (p->arg.category_anyof_mask && !(categories & p->arg.category_anyof_mask))
+		return false;
+
+	return true;
+}
+
+static bool pagemap_scan_is_interesting_vma(unsigned long categories,
+					    const struct pagemap_scan_private *p)
+{
+	unsigned long required = p->arg.category_mask & PAGE_IS_WPALLOWED;
+
+	categories ^= p->arg.category_inverted;
+	if ((categories & required) != required)
+		return false;
+
+	return true;
+}
+
+static int pagemap_scan_test_walk(unsigned long start, unsigned long end,
+				  struct mm_walk *walk)
+{
+	struct pagemap_scan_private *p = walk->private;
+	struct vm_area_struct *vma = walk->vma;
+	unsigned long vma_category = 0;
+	bool wp_allowed = userfaultfd_wp_async(vma) &&
+	    userfaultfd_wp_use_markers(vma);
+
+	if (!wp_allowed) {
+		/* User requested explicit failure over wp-async capability */
+		if (p->arg.flags & PM_SCAN_CHECK_WPASYNC)
+			return -EPERM;
+		/*
+		 * User requires wr-protect, and allows silently skipping
+		 * unsupported vmas.
+		 */
+		if (p->arg.flags & PM_SCAN_WP_MATCHING)
+			return 1;
+		/*
+		 * Then the request doesn't involve wr-protects at all,
+		 * fall through to the rest checks, and allow vma walk.
+		 */
+	}
+
+	if (vma->vm_flags & VM_PFNMAP)
+		return 1;
+
+	if (wp_allowed)
+		vma_category |= PAGE_IS_WPALLOWED;
+
+	if (vma->vm_flags & VM_SOFTDIRTY)
+		vma_category |= PAGE_IS_SOFT_DIRTY;
+
+	if (!pagemap_scan_is_interesting_vma(vma_category, p))
+		return 1;
+
+	p->cur_vma_category = vma_category;
+
+	return 0;
+}
+
+static bool pagemap_scan_push_range(unsigned long categories,
+				    struct pagemap_scan_private *p,
+				    unsigned long addr, unsigned long end)
+{
+	struct page_region *cur_buf = &p->vec_buf[p->vec_buf_index];
+
+	/*
+	 * When there is no output buffer provided at all, the sentinel values
+	 * won't match here. There is no other way for `cur_buf->end` to be
+	 * non-zero other than it being non-empty.
+	 */
+	if (addr == cur_buf->end && categories == cur_buf->categories) {
+		cur_buf->end = end;
+		return true;
+	}
+
+	if (cur_buf->end) {
+		if (p->vec_buf_index >= p->vec_buf_len - 1)
+			return false;
+
+		cur_buf = &p->vec_buf[++p->vec_buf_index];
+	}
+
+	cur_buf->start = addr;
+	cur_buf->end = end;
+	cur_buf->categories = categories;
+
+	return true;
+}
+
+static int pagemap_scan_output(unsigned long categories,
+			       struct pagemap_scan_private *p,
+			       unsigned long addr, unsigned long *end)
+{
+	unsigned long n_pages, total_pages;
+	int ret = 0;
+
+	if (!p->vec_buf)
+		return 0;
+
+	categories &= p->arg.return_mask;
+
+	n_pages = (*end - addr) / PAGE_SIZE;
+	if (check_add_overflow(p->found_pages, n_pages, &total_pages) ||
+	    total_pages > p->arg.max_pages) {
+		size_t n_too_much = total_pages - p->arg.max_pages;
+		*end -= n_too_much * PAGE_SIZE;
+		n_pages -= n_too_much;
+		ret = -ENOSPC;
+	}
+
+	if (!pagemap_scan_push_range(categories, p, addr, *end)) {
+		*end = addr;
+		n_pages = 0;
+		ret = -ENOSPC;
+	}
+
+	p->found_pages += n_pages;
+	if (ret)
+		p->arg.walk_end = *end;
+
+	return ret;
+}
+
+static int pagemap_scan_thp_entry(pmd_t *pmd, unsigned long start,
+				  unsigned long end, struct mm_walk *walk)
+{
+#ifdef CONFIG_TRANSPARENT_HUGEPAGE
+	struct pagemap_scan_private *p = walk->private;
+	struct vm_area_struct *vma = walk->vma;
+	unsigned long categories;
+	spinlock_t *ptl;
+	int ret = 0;
+
+	ptl = pmd_trans_huge_lock(pmd, vma);
+	if (!ptl)
+		return -ENOENT;
+
+	categories = p->cur_vma_category |
+		     pagemap_thp_category(p, vma, start, *pmd);
+
+	if (!pagemap_scan_is_interesting_page(categories, p))
+		goto out_unlock;
+
+	ret = pagemap_scan_output(categories, p, start, &end);
+	if (start == end)
+		goto out_unlock;
+
+	if (~p->arg.flags & PM_SCAN_WP_MATCHING)
+		goto out_unlock;
+	if (~categories & PAGE_IS_WRITTEN)
+		goto out_unlock;
+
+	/*
+	 * Break huge page into small pages if the WP operation
+	 * needs to be performed on a portion of the huge page.
+	 */
+	if (end != start + HPAGE_SIZE) {
+		spin_unlock(ptl);
+		split_huge_pmd(vma, pmd, start);
+		pagemap_scan_backout_range(p, start, end);
+		/* Report as if there was no THP */
+		return -ENOENT;
+	}
+
+	make_uffd_wp_pmd(vma, start, pmd);
+	flush_tlb_range(vma, start, end);
+out_unlock:
+	spin_unlock(ptl);
+	return ret;
+#else /* !CONFIG_TRANSPARENT_HUGEPAGE */
+	return -ENOENT;
+#endif
+}
+
+static int pagemap_scan_pmd_entry(pmd_t *pmd, unsigned long start,
+				  unsigned long end, struct mm_walk *walk)
+{
+	struct pagemap_scan_private *p = walk->private;
+	struct vm_area_struct *vma = walk->vma;
+	unsigned long addr, flush_end = 0;
+	pte_t *pte, *start_pte;
+	spinlock_t *ptl;
+	int ret;
+
+	ret = pagemap_scan_thp_entry(pmd, start, end, walk);
+	if (ret != -ENOENT)
+		return ret;
+
+	ret = 0;
+	start_pte = pte = pte_offset_map_lock(vma->vm_mm, pmd, start, &ptl);
+	if (!pte) {
+		walk->action = ACTION_AGAIN;
+		return 0;
+	}
+
+	lazy_mmu_mode_enable();
+
+	if ((p->arg.flags & PM_SCAN_WP_MATCHING) && !p->vec_out) {
+		/* Fast path for performing exclusive WP */
+		for (addr = start; addr != end; pte++, addr += PAGE_SIZE) {
+			pte_t ptent = ptep_get(pte);
+
+			if ((pte_present(ptent) && pte_uffd(ptent)) ||
+			    pte_swp_uffd_any(ptent))
+				continue;
+			make_uffd_wp_pte(vma, addr, pte, ptent);
+			if (!flush_end)
+				start = addr;
+			flush_end = addr + PAGE_SIZE;
+		}
+		goto flush_and_return;
+	}
+
+	if (userfaultfd_wp(vma) && !p->arg.category_anyof_mask &&
+	    !p->arg.category_inverted &&
+	    p->arg.category_mask == PAGE_IS_WRITTEN &&
+	    p->arg.return_mask == PAGE_IS_WRITTEN) {
+		for (addr = start; addr < end; pte++, addr += PAGE_SIZE) {
+			unsigned long next = addr + PAGE_SIZE;
+			pte_t ptent = ptep_get(pte);
+
+			if ((pte_present(ptent) && pte_uffd(ptent)) ||
+			    pte_swp_uffd_any(ptent))
+				continue;
+			ret = pagemap_scan_output(p->cur_vma_category | PAGE_IS_WRITTEN,
+						  p, addr, &next);
+			if (next == addr)
+				break;
+			if (~p->arg.flags & PM_SCAN_WP_MATCHING)
+				continue;
+			make_uffd_wp_pte(vma, addr, pte, ptent);
+			if (!flush_end)
+				start = addr;
+			flush_end = next;
+		}
+		goto flush_and_return;
+	}
+
+	for (addr = start; addr != end; pte++, addr += PAGE_SIZE) {
+		pte_t ptent = ptep_get(pte);
+		unsigned long categories = p->cur_vma_category |
+					   pagemap_page_category(p, vma, addr, ptent);
+		unsigned long next = addr + PAGE_SIZE;
+
+		if (!pagemap_scan_is_interesting_page(categories, p))
+			continue;
+
+		ret = pagemap_scan_output(categories, p, addr, &next);
+		if (next == addr)
+			break;
+
+		if (~p->arg.flags & PM_SCAN_WP_MATCHING)
+			continue;
+		if (~categories & PAGE_IS_WRITTEN)
+			continue;
+
+		make_uffd_wp_pte(vma, addr, pte, ptent);
+		if (!flush_end)
+			start = addr;
+		flush_end = next;
+	}
+
+flush_and_return:
+	if (flush_end)
+		flush_tlb_range(vma, start, addr);
+
+	lazy_mmu_mode_disable();
+	pte_unmap_unlock(start_pte, ptl);
+
+	cond_resched();
+	return ret;
+}
+
+#ifdef CONFIG_HUGETLB_PAGE
+static int pagemap_scan_hugetlb_entry(pte_t *ptep, unsigned long hmask,
+				      unsigned long start, unsigned long end,
+				      struct mm_walk *walk)
+{
+	struct pagemap_scan_private *p = walk->private;
+	struct vm_area_struct *vma = walk->vma;
+	unsigned long categories;
+	spinlock_t *ptl;
+	int ret = 0;
+	pte_t pte;
+
+	if (~p->arg.flags & PM_SCAN_WP_MATCHING) {
+		/* Go the short route when not write-protecting pages. */
+
+		pte = huge_ptep_get(walk->mm, start, ptep);
+		categories = p->cur_vma_category |
+			     pagemap_hugetlb_category(vma, pte);
+
+		if (!pagemap_scan_is_interesting_page(categories, p))
+			return 0;
+
+		return pagemap_scan_output(categories, p, start, &end);
+	}
+
+	i_mmap_lock_write(vma->vm_file->f_mapping);
+	ptl = huge_pte_lock(hstate_vma(vma), vma->vm_mm, ptep);
+
+	pte = huge_ptep_get(walk->mm, start, ptep);
+	categories = p->cur_vma_category | pagemap_hugetlb_category(vma, pte);
+
+	if (!pagemap_scan_is_interesting_page(categories, p))
+		goto out_unlock;
+
+	ret = pagemap_scan_output(categories, p, start, &end);
+	if (start == end)
+		goto out_unlock;
+
+	if (~categories & PAGE_IS_WRITTEN)
+		goto out_unlock;
+
+	if (end != start + huge_page_size(hstate_vma(vma))) {
+		/* Partial HugeTLB page WP isn't possible. */
+		pagemap_scan_backout_range(p, start, end);
+		p->arg.walk_end = start;
+		ret = 0;
+		goto out_unlock;
+	}
+
+	make_uffd_wp_huge_pte(vma, start, ptep, pte);
+	flush_hugetlb_tlb_range(vma, start, end);
+
+out_unlock:
+	spin_unlock(ptl);
+	i_mmap_unlock_write(vma->vm_file->f_mapping);
+
+	return ret;
+}
+
+/*
+ * Write-protect the unpopulated hugetlb entries covering [addr, end) by
+ * installing uffd-wp markers inline, exactly as pagemap_scan_hugetlb_entry()
+ * does for populated entries.
+ *
+ * walk_hugetlb_range() currently calls ->pte_hole() once per huge page, so the
+ * loop normally runs a single iteration; it is written to cover the full range
+ * in case the walker ever coalesces adjacent holes.
+ *
+ * The obvious route -- uffd_wp_range() -> hugetlb_change_protection() --
+ * cannot be used here: it takes hugetlb_vma_lock_write(), but the page-table
+ * walker (walk_hugetlb_range()) already holds hugetlb_vma_lock_read() on the
+ * same VMA, so the scanning thread would deadlock against itself. PMD sharing
+ * is disabled on uffd-wp VMAs (hugetlb_unshare_all_pmds() at registration), so
+ * the vma lock guards nothing that matters for these entries anyway.
+ */
+static int pagemap_scan_hugetlb_hole_wp(struct vm_area_struct *vma,
+					unsigned long addr, unsigned long end)
+{
+	struct hstate *h = hstate_vma(vma);
+	unsigned long psize = huge_page_size(h);
+	struct mm_struct *mm = vma->vm_mm;
+	spinlock_t *ptl;
+	pte_t *ptep;
+	pte_t pte;
+
+	for (addr = ALIGN_DOWN(addr, psize); addr < end; addr += psize) {
+		ptep = huge_pte_alloc(mm, vma, addr, psize);
+		if (!ptep)
+			return -ENOMEM;
+
+		i_mmap_lock_write(vma->vm_file->f_mapping);
+		ptl = huge_pte_lock(h, mm, ptep);
+		pte = huge_ptep_get(mm, addr, ptep);
+		make_uffd_wp_huge_pte(vma, addr, ptep, pte);
+		/*
+		 * A none entry has no cached translation, so installing the
+		 * marker needs no TLB flush. Flush only if a fault populated
+		 * the entry between huge_pte_alloc() and the page table lock.
+		 */
+		if (!huge_pte_none(pte))
+			flush_hugetlb_tlb_range(vma, addr, addr + psize);
+		spin_unlock(ptl);
+		i_mmap_unlock_write(vma->vm_file->f_mapping);
+	}
+
+	return 0;
+}
+#else
+#define pagemap_scan_hugetlb_entry NULL
+static int pagemap_scan_hugetlb_hole_wp(struct vm_area_struct *vma,
+					unsigned long addr, unsigned long end)
+{
+	return 0;
+}
+#endif
+
+static int pagemap_scan_pte_hole(unsigned long addr, unsigned long end,
+				 int depth, struct mm_walk *walk)
+{
+	struct pagemap_scan_private *p = walk->private;
+	struct vm_area_struct *vma = walk->vma;
+	unsigned long categories;
+	int ret, err;
+
+	if (!vma)
+		return 0;
+
+	/*
+	 * In a uffd-wp VMA an unpopulated range is treated as written:
+	 * uffd-wp registration populates page tables and installs markers
+	 * with WP_UNPOPULATED, so a missing marker means the range was
+	 * zapped. See the pte_none() handling in pagemap_page_category().
+	 *
+	 * hugetlb differs, see pagemap_hugetlb_category().
+	 */
+	categories = p->cur_vma_category;
+	if (userfaultfd_wp(vma) && !is_vm_hugetlb_page(vma))
+		categories |= PAGE_IS_WRITTEN;
+
+	if (!pagemap_scan_is_interesting_page(categories, p))
+		return 0;
+
+	ret = pagemap_scan_output(categories, p, addr, &end);
+	if (addr == end)
+		return ret;
+
+	if (~p->arg.flags & PM_SCAN_WP_MATCHING)
+		return ret;
+
+	if (is_vm_hugetlb_page(vma))
+		err = pagemap_scan_hugetlb_hole_wp(vma, addr, end);
+	else
+		err = uffd_wp_range(vma, addr, end - addr, true);
+	if (err < 0)
+		ret = err;
+
+	return ret;
+}
+
+static const struct mm_walk_ops pagemap_scan_ops = {
+	.test_walk = pagemap_scan_test_walk,
+	.pmd_entry = pagemap_scan_pmd_entry,
+	.pte_hole = pagemap_scan_pte_hole,
+	.hugetlb_entry = pagemap_scan_hugetlb_entry,
+};
+
+static int pagemap_scan_get_args(struct pm_scan_arg *arg,
+				 unsigned long uarg)
+{
+	if (copy_from_user(arg, (void __user *)uarg, sizeof(*arg)))
+		return -EFAULT;
+
+	if (arg->size != sizeof(struct pm_scan_arg))
+		return -EINVAL;
+
+	/* Validate requested features */
+	if (arg->flags & ~PM_SCAN_FLAGS)
+		return -EINVAL;
+	if ((arg->category_inverted | arg->category_mask |
+	     arg->category_anyof_mask | arg->return_mask) & ~PM_SCAN_CATEGORIES)
+		return -EINVAL;
+
+	arg->start = untagged_addr((unsigned long)arg->start);
+	arg->end = untagged_addr((unsigned long)arg->end);
+	arg->vec = untagged_addr((unsigned long)arg->vec);
+
+	/* Validate memory pointers */
+	if (!IS_ALIGNED(arg->start, PAGE_SIZE))
+		return -EINVAL;
+	if (!access_ok((void __user *)(long)arg->start, arg->end - arg->start))
+		return -EFAULT;
+	if (!arg->vec && arg->vec_len)
+		return -EINVAL;
+	if (UINT_MAX == SIZE_MAX && arg->vec_len > SIZE_MAX)
+		return -EINVAL;
+	if (arg->vec && !access_ok((void __user *)(long)arg->vec,
+				   size_mul(arg->vec_len, sizeof(struct page_region))))
+		return -EFAULT;
+
+	/* Fixup default values */
+	arg->end = ALIGN(arg->end, PAGE_SIZE);
+	arg->walk_end = 0;
+	if (!arg->max_pages)
+		arg->max_pages = ULONG_MAX;
+
+	return 0;
+}
+
+static int pagemap_scan_writeback_args(struct pm_scan_arg *arg,
+				       unsigned long uargl)
+{
+	struct pm_scan_arg __user *uarg	= (void __user *)uargl;
+
+	if (copy_to_user(&uarg->walk_end, &arg->walk_end, sizeof(arg->walk_end)))
+		return -EFAULT;
+
+	return 0;
+}
+
+static int pagemap_scan_init_bounce_buffer(struct pagemap_scan_private *p)
+{
+	if (!p->arg.vec_len)
+		return 0;
+
+	p->vec_buf_len = min_t(size_t, PAGEMAP_WALK_SIZE >> PAGE_SHIFT,
+			       p->arg.vec_len);
+	p->vec_buf = kmalloc_objs(*p->vec_buf, p->vec_buf_len);
+	if (!p->vec_buf)
+		return -ENOMEM;
+
+	p->vec_buf->start = p->vec_buf->end = 0;
+	p->vec_out = (struct page_region __user *)(long)p->arg.vec;
+
+	return 0;
+}
+
+static long pagemap_scan_flush_buffer(struct pagemap_scan_private *p)
+{
+	const struct page_region *buf = p->vec_buf;
+	long n = p->vec_buf_index;
+
+	if (!p->vec_buf)
+		return 0;
+
+	if (buf[n].end != buf[n].start)
+		n++;
+
+	if (!n)
+		return 0;
+
+	if (copy_to_user(p->vec_out, buf, n * sizeof(*buf)))
+		return -EFAULT;
+
+	p->arg.vec_len -= n;
+	p->vec_out += n;
+
+	p->vec_buf_index = 0;
+	p->vec_buf_len = min_t(size_t, p->vec_buf_len, p->arg.vec_len);
+	p->vec_buf->start = p->vec_buf->end = 0;
+
+	return n;
+}
+
+static long do_pagemap_scan(struct mm_struct *mm, unsigned long uarg)
+{
+	struct pagemap_scan_private p = {0};
+	unsigned long walk_start;
+	size_t n_ranges_out = 0;
+	int ret;
+
+	ret = pagemap_scan_get_args(&p.arg, uarg);
+	if (ret)
+		return ret;
+
+	p.masks_of_interest = p.arg.category_mask | p.arg.category_anyof_mask |
+			      p.arg.return_mask;
+	ret = pagemap_scan_init_bounce_buffer(&p);
+	if (ret)
+		return ret;
+
+	for (walk_start = p.arg.start; walk_start < p.arg.end;
+			walk_start = p.arg.walk_end) {
+		struct mmu_notifier_range range;
+		long n_out;
+
+		if (fatal_signal_pending(current)) {
+			ret = -EINTR;
+			break;
+		}
+
+		ret = mmap_read_lock_killable(mm);
+		if (ret)
+			break;
+
+		/* Protection change for the range is going to happen. */
+		if (p.arg.flags & PM_SCAN_WP_MATCHING) {
+			mmu_notifier_range_init(&range, MMU_NOTIFY_PROTECTION_VMA, 0,
+						mm, walk_start, p.arg.end);
+			mmu_notifier_invalidate_range_start(&range);
+		}
+
+		ret = walk_page_range(mm, walk_start, p.arg.end,
+				      &pagemap_scan_ops, &p);
+
+		if (p.arg.flags & PM_SCAN_WP_MATCHING)
+			mmu_notifier_invalidate_range_end(&range);
+
+		mmap_read_unlock(mm);
+
+		n_out = pagemap_scan_flush_buffer(&p);
+		if (n_out < 0)
+			ret = n_out;
+		else
+			n_ranges_out += n_out;
+
+		if (ret != -ENOSPC)
+			break;
+
+		if (p.arg.vec_len == 0 || p.found_pages == p.arg.max_pages)
+			break;
+	}
+
+	/* ENOSPC signifies early stop (buffer full) from the walk. */
+	if (!ret || ret == -ENOSPC)
+		ret = n_ranges_out;
+
+	/* The walk_end isn't set when ret is zero */
+	if (!p.arg.walk_end)
+		p.arg.walk_end = p.arg.end;
+	if (pagemap_scan_writeback_args(&p.arg, uarg))
+		ret = -EFAULT;
+
+	kfree(p.vec_buf);
+	return ret;
+}
+
+static long do_pagemap_cmd(struct file *file, unsigned int cmd,
+			   unsigned long arg)
+{
+	struct mm_struct *mm = file->private_data;
+
+	switch (cmd) {
+	case PAGEMAP_SCAN:
+		return do_pagemap_scan(mm, arg);
+
+	default:
+		return -EINVAL;
+	}
+}
+
+const struct file_operations proc_pagemap_operations = {
+	.llseek		= mem_lseek, /* borrow this */
+	.read		= pagemap_read,
+	.open		= pagemap_open,
+	.release	= pagemap_release,
+	.unlocked_ioctl = do_pagemap_cmd,
+	.compat_ioctl	= do_pagemap_cmd,
+};
+#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)
+{
+	struct folio *folio = page_folio(page);
+	int count;
+
+	if (IS_ENABLED(CONFIG_PAGE_MAPCOUNT))
+		count = folio_precise_page_mapcount(folio, page);
+	else
+		count = folio_average_page_mapcount(folio);
+
+	md->pages += nr_pages;
+	if (pte_dirty || folio_test_dirty(folio))
+		md->dirty += nr_pages;
+
+	if (folio_test_swapcache(folio))
+		md->swapcache += nr_pages;
+
+	if (folio_test_active(folio) || folio_test_unevictable(folio))
+		md->active += nr_pages;
+
+	if (folio_test_writeback(folio))
+		md->writeback += nr_pages;
+
+	if (folio_test_anon(folio))
+		md->anon += nr_pages;
+
+	if (count > md->mapcount_max)
+		md->mapcount_max = count;
+
+	md->node[folio_nid(folio)] += 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 || is_zone_device_page(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;
+	}
+#endif
+	orig_pte = pte = pte_offset_map_lock(walk->mm, pmd, addr, &ptl);
+	if (!pte) {
+		walk->action = ACTION_AGAIN;
+		return 0;
+	}
+	do {
+		pte_t ptent = ptep_get(pte);
+		struct page *page = can_gather_numa_stats(ptent, vma, addr);
+		if (!page)
+			continue;
+		gather_stats(page, md, pte_dirty(ptent), 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;
+	struct numa_maps *md;
+	struct page *page;
+	spinlock_t *ptl;
+
+	ptl = huge_pte_lock(hstate_vma(walk->vma), walk->mm, pte);
+	huge_pte = huge_ptep_get(walk->mm, addr, pte);
+	if (!pte_present(huge_pte))
+		goto out;
+
+	page = pte_page(huge_pte);
+
+	md = walk->private;
+	gather_stats(page, md, pte_dirty(huge_pte), 1);
+out:
+	spin_unlock(ptl);
+	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,
+	.walk_lock = PGWALK_RDLOCK,
+};
+
+#ifdef CONFIG_PER_VMA_LOCK
+static const struct mm_walk_ops show_numa_vma_lock_ops = {
+	.hugetlb_entry = gather_hugetlb_stats,
+	.pmd_entry = gather_pte_stats,
+	.walk_lock = PGWALK_VMA_RDLOCK_VERIFY,
+};
+
+static inline const struct mm_walk_ops *
+get_show_numa_ops(struct proc_maps_private *priv)
+{
+	if (priv->lock_ctx.mmap_locked)
+		return &show_numa_ops;
+	return &show_numa_vma_lock_ops;
+}
+
+#else /* CONFIG_PER_VMA_LOCK */
+
+static inline const struct mm_walk_ops *
+get_show_numa_ops(struct proc_maps_private *priv)
+{
+	return &show_numa_ops;
+}
+
+#endif /* CONFIG_PER_VMA_LOCK */
+
+/*
+ * 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;
+	char buffer[64];
+	struct mempolicy *pol;
+	pgoff_t ilx;
+	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, &ilx);
+	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_path(m, file_user_path(file), "\n\t= ");
+	} else if (vma_is_initial_heap(vma)) {
+		seq_puts(m, " heap");
+	} else if (vma_is_initial_stack(vma)) {
+		seq_puts(m, " stack");
+	}
+
+	if (is_vm_hugetlb_page(vma))
+		seq_puts(m, " huge");
+
+	/* Skip walking pages if gate VMA */
+	if (vma != get_gate_vma(proc_priv->lock_ctx.mm)) {
+		/* Might sleep. Drop RCU read lock but keep the VMA locked. */
+		drop_rcu(proc_priv);
+		walk_page_vma(vma, get_show_numa_ops(proc_priv), md);
+		reacquire_rcu(proc_priv);
+	}
+
+	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 */