diff --git a/arch/openrisc/kernel/dma.c b/arch/openrisc/kernel/dma.c
index b3edbb33b621..0b4c20cc76cb 100644
--- a/arch/openrisc/kernel/dma.c
+++ b/arch/openrisc/kernel/dma.c
@@ -75,7 +75,7 @@ void *arch_dma_set_uncached(void *cpu_addr, size_t size)
 	 * them and setting the cache-inhibit bit.
 	 */
 	mmap_write_lock(&init_mm);
-	error = walk_page_range_novma(&init_mm, va, va + size,
+	error = walk_kernel_page_table_range(va, va + size,
 			&set_nocache_walk_ops, NULL, NULL);
 	mmap_write_unlock(&init_mm);
 
@@ -90,7 +90,7 @@ void arch_dma_clear_uncached(void *cpu_addr, size_t size)
 
 	mmap_write_lock(&init_mm);
 	/* walk_page_range shouldn't be able to fail here */
-	WARN_ON(walk_page_range_novma(&init_mm, va, va + size,
+	WARN_ON(walk_kernel_page_table_range(va, va + size,
 			&clear_nocache_walk_ops, NULL, NULL));
 	mmap_write_unlock(&init_mm);
 }
diff --git a/arch/riscv/mm/pageattr.c b/arch/riscv/mm/pageattr.c
index 271d01a5ba4d..a35edf662d7e 100644
--- a/arch/riscv/mm/pageattr.c
+++ b/arch/riscv/mm/pageattr.c
@@ -299,7 +299,7 @@ static int __set_memory(unsigned long addr, int numpages, pgprot_t set_mask,
 			if (ret)
 				goto unlock;
 
-			ret = walk_page_range_novma(&init_mm, lm_start, lm_end,
+			ret = walk_kernel_page_table_range(lm_start, lm_end,
 						    &pageattr_ops, NULL, &masks);
 			if (ret)
 				goto unlock;
@@ -317,13 +317,13 @@ static int __set_memory(unsigned long addr, int numpages, pgprot_t set_mask,
 		if (ret)
 			goto unlock;
 
-		ret = walk_page_range_novma(&init_mm, lm_start, lm_end,
+		ret = walk_kernel_page_table_range(lm_start, lm_end,
 					    &pageattr_ops, NULL, &masks);
 		if (ret)
 			goto unlock;
 	}
 
-	ret =  walk_page_range_novma(&init_mm, start, end, &pageattr_ops, NULL,
+	ret =  walk_kernel_page_table_range(start, end, &pageattr_ops, NULL,
 				     &masks);
 
 unlock:
@@ -335,7 +335,7 @@ unlock:
 	 */
 	flush_tlb_all();
 #else
-	ret =  walk_page_range_novma(&init_mm, start, end, &pageattr_ops, NULL,
+	ret =  walk_kernel_page_table_range(start, end, &pageattr_ops, NULL,
 				     &masks);
 
 	mmap_write_unlock(&init_mm);
diff --git a/include/linux/pagewalk.h b/include/linux/pagewalk.h
index 27cd1e59ccf7..49bf5308786f 100644
--- a/include/linux/pagewalk.h
+++ b/include/linux/pagewalk.h
@@ -117,10 +117,9 @@ struct mm_walk {
 int walk_page_range(struct mm_struct *mm, unsigned long start,
 		unsigned long end, const struct mm_walk_ops *ops,
 		void *private);
-int walk_page_range_novma(struct mm_struct *mm, unsigned long start,
-			  unsigned long end, const struct mm_walk_ops *ops,
-			  pgd_t *pgd,
-			  void *private);
+int walk_kernel_page_table_range(unsigned long start,
+		unsigned long end, const struct mm_walk_ops *ops,
+		pgd_t *pgd, void *private);
 int walk_page_range_vma(struct vm_area_struct *vma, unsigned long start,
 			unsigned long end, const struct mm_walk_ops *ops,
 			void *private);
diff --git a/mm/internal.h b/mm/internal.h
index f773db493a99..03cfd9f73659 100644
--- a/mm/internal.h
+++ b/mm/internal.h
@@ -10,6 +10,7 @@
 #include <linux/fs.h>
 #include <linux/mm.h>
 #include <linux/pagemap.h>
+#include <linux/pagewalk.h>
 #include <linux/rmap.h>
 #include <linux/tracepoint-defs.h>
 
@@ -1229,4 +1230,10 @@ struct vma_prepare {
 	struct vm_area_struct *remove;
 	struct vm_area_struct *remove2;
 };
+
+/* pagewalk.c */
+int walk_page_range_debug(struct mm_struct *mm, unsigned long start,
+			  unsigned long end, const struct mm_walk_ops *ops,
+			  pgd_t *pgd, void *private);
+
 #endif	/* __MM_INTERNAL_H */
diff --git a/mm/pagewalk.c b/mm/pagewalk.c
index b7d7e4fcfad7..20df9f6ccd48 100644
--- a/mm/pagewalk.c
+++ b/mm/pagewalk.c
@@ -527,8 +527,7 @@ int walk_page_range(struct mm_struct *mm, unsigned long start,
 }
 
 /**
- * walk_page_range_novma - walk a range of pagetables not backed by a vma
- * @mm:		mm_struct representing the target process of page table walk
+ * walk_kernel_page_table_range - walk a range of kernel pagetables.
  * @start:	start address of the virtual address range
  * @end:	end address of the virtual address range
  * @ops:	operation to call during the walk
@@ -538,12 +537,59 @@ int walk_page_range(struct mm_struct *mm, unsigned long start,
  * Similar to walk_page_range() but can walk any page tables even if they are
  * not backed by VMAs. Because 'unusual' entries may be walked this function
  * will also not lock the PTEs for the pte_entry() callback. This is useful for
- * walking the kernel pages tables or page tables for firmware.
+ * walking kernel pages tables or page tables for firmware.
+ *
+ * Note: Be careful to walk the kernel pages tables, the caller may be need to
+ * take other effective approaches (mmap lock may be insufficient) to prevent
+ * the intermediate kernel page tables belonging to the specified address range
+ * from being freed (e.g. memory hot-remove).
  */
-int walk_page_range_novma(struct mm_struct *mm, unsigned long start,
+int walk_kernel_page_table_range(unsigned long start, unsigned long end,
+		const struct mm_walk_ops *ops, pgd_t *pgd, void *private)
+{
+	struct mm_struct *mm = &init_mm;
+	struct mm_walk walk = {
+		.ops		= ops,
+		.mm		= mm,
+		.pgd		= pgd,
+		.private	= private,
+		.no_vma		= true
+	};
+
+	if (start >= end)
+		return -EINVAL;
+
+	/*
+	 * Kernel intermediate page tables are usually not freed, so the mmap
+	 * read lock is sufficient. But there are some exceptions.
+	 * E.g. memory hot-remove. In which case, the mmap lock is insufficient
+	 * to prevent the intermediate kernel pages tables belonging to the
+	 * specified address range from being freed. The caller should take
+	 * other actions to prevent this race.
+	 */
+	mmap_assert_locked(mm);
+
+	return walk_pgd_range(start, end, &walk);
+}
+
+/**
+ * walk_page_range_debug - walk a range of pagetables not backed by a vma
+ * @mm:		mm_struct representing the target process of page table walk
+ * @start:	start address of the virtual address range
+ * @end:	end address of the virtual address range
+ * @ops:	operation to call during the walk
+ * @pgd:	pgd to walk if different from mm->pgd
+ * @private:	private data for callbacks' usage
+ *
+ * Similar to walk_page_range() but can walk any page tables even if they are
+ * not backed by VMAs. Because 'unusual' entries may be walked this function
+ * will also not lock the PTEs for the pte_entry() callback.
+ *
+ * This is for debugging purposes ONLY.
+ */
+int walk_page_range_debug(struct mm_struct *mm, unsigned long start,
 			  unsigned long end, const struct mm_walk_ops *ops,
-			  pgd_t *pgd,
-			  void *private)
+			  pgd_t *pgd, void *private)
 {
 	struct mm_walk walk = {
 		.ops		= ops,
@@ -553,10 +599,22 @@ int walk_page_range_novma(struct mm_struct *mm, unsigned long start,
 		.no_vma		= true
 	};
 
+	/* For convenience, we allow traversal of kernel mappings. */
+	if (mm == &init_mm)
+		return walk_kernel_page_table_range(start, end, ops,
+						    pgd, private);
 	if (start >= end || !walk.mm)
 		return -EINVAL;
 
-	mmap_assert_write_locked(walk.mm);
+	/*
+	 * The mmap lock protects the page walker from changes to the page
+	 * tables during the walk.  However a read lock is insufficient to
+	 * protect those areas which don't have a VMA as munmap() detaches
+	 * the VMAs before downgrading to a read lock and actually tearing
+	 * down PTEs/page tables. In which case, the mmap write lock should
+	 * be held.
+	 */
+	mmap_assert_write_locked(mm);
 
 	return walk_pgd_range(start, end, &walk);
 }
diff --git a/mm/ptdump.c b/mm/ptdump.c
index e46df2c24d85..616a54c0cc42 100644
--- a/mm/ptdump.c
+++ b/mm/ptdump.c
@@ -3,6 +3,7 @@
 #include <linux/pagewalk.h>
 #include <linux/ptdump.h>
 #include <linux/kasan.h>
+#include "internal.h"
 
 #if defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS)
 /*
@@ -155,7 +156,7 @@ void ptdump_walk_pgd(struct ptdump_state *st, struct mm_struct *mm, pgd_t *pgd)
 	get_online_mems();
 	mmap_write_lock(mm);
 	while (range->start != range->end) {
-		walk_page_range_novma(mm, range->start, range->end,
+		walk_page_range_debug(mm, range->start, range->end,
 				      &ptdump_ops, pgd, st);
 		range++;
 	}