4.11-stable review patch. If anyone has any objections, please let me know.
------------------
From: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
commit bfb9956ab4d8242f4594b5f4bee534b935384fd9 upstream.
The page table dump code doesn't know about huge pages, so currently
it crashes (or walks random memory, usually leading to a crash), if it
finds a huge page. On Book3S we only see huge pages in the Linux page
tables when we're using the P9 Radix MMU.
Teaching the code to properly handle huge pages is a bit more involved,
so for now just prevent the crash.
Fixes: 8eb07b187000 ("powerpc/mm: Dump linux pagetables")
Signed-off-by: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
arch/powerpc/mm/dump_linuxpagetables.c | 7 ++++---
1 file changed, 4 insertions(+), 3 deletions(-)
--- a/arch/powerpc/mm/dump_linuxpagetables.c
+++ b/arch/powerpc/mm/dump_linuxpagetables.c
@@ -16,6 +16,7 @@
*/
#include <linux/debugfs.h>
#include <linux/fs.h>
+#include <linux/hugetlb.h>
#include <linux/io.h>
#include <linux/mm.h>
#include <linux/sched.h>
@@ -331,7 +332,7 @@ static void walk_pmd(struct pg_state *st
for (i = 0; i < PTRS_PER_PMD; i++, pmd++) {
addr = start + i * PMD_SIZE;
- if (!pmd_none(*pmd))
+ if (!pmd_none(*pmd) && !pmd_huge(*pmd))
/* pmd exists */
walk_pte(st, pmd, addr);
else
@@ -347,7 +348,7 @@ static void walk_pud(struct pg_state *st
for (i = 0; i < PTRS_PER_PUD; i++, pud++) {
addr = start + i * PUD_SIZE;
- if (!pud_none(*pud))
+ if (!pud_none(*pud) && !pud_huge(*pud))
/* pud exists */
walk_pmd(st, pud, addr);
else
@@ -367,7 +368,7 @@ static void walk_pagetables(struct pg_st
*/
for (i = 0; i < PTRS_PER_PGD; i++, pgd++) {
addr = KERN_VIRT_START + i * PGDIR_SIZE;
- if (!pgd_none(*pgd))
+ if (!pgd_none(*pgd) && !pgd_huge(*pgd))
/* pgd exists */
walk_pud(st, pgd, addr);
else