[PATCH 4.19 003/205] powerpc/mm: Fix page table dump to work on Radix

[Greg Kroah-Hartman]

4.19-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Michael Ellerman <mpe@xxxxxxxxxxxxxx>

[ Upstream commit 0d923962ab69c27cca664a2d535e90ef655110ca ]

When we're running on Book3S with the Radix MMU enabled the page table
dump currently prints the wrong addresses because it uses the wrong
start address.

Fix it to use PAGE_OFFSET rather than KERN_VIRT_START.

Signed-off-by: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 arch/powerpc/mm/dump_linuxpagetables.c |   12 +++++++++---
 1 file changed, 9 insertions(+), 3 deletions(-)

--- a/arch/powerpc/mm/dump_linuxpagetables.c
+++ b/arch/powerpc/mm/dump_linuxpagetables.c
@@ -418,12 +418,13 @@ static void walk_pagetables(struct pg_st
 	unsigned int i;
 	unsigned long addr;
 
+	addr = st->start_address;
+
 	/*
 	 * Traverse the linux pagetable structure and dump pages that are in
 	 * the hash pagetable.
 	 */
-	for (i = 0; i < PTRS_PER_PGD; i++, pgd++) {
-		addr = KERN_VIRT_START + i * PGDIR_SIZE;
+	for (i = 0; i < PTRS_PER_PGD; i++, pgd++, addr += PGDIR_SIZE) {
 		if (!pgd_none(*pgd) && !pgd_huge(*pgd))
 			/* pgd exists */
 			walk_pud(st, pgd, addr);
@@ -472,9 +473,14 @@ static int ptdump_show(struct seq_file *
 {
 	struct pg_state st = {
 		.seq = m,
-		.start_address = KERN_VIRT_START,
 		.marker = address_markers,
 	};
+
+	if (radix_enabled())
+		st.start_address = PAGE_OFFSET;
+	else
+		st.start_address = KERN_VIRT_START;
+
 	/* Traverse kernel page tables */
 	walk_pagetables(&st);
 	note_page(&st, 0, 0, 0);