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authorMichael Ellerman <mpe@ellerman.id.au>2017-05-16 20:42:53 +1000
committerMichael Ellerman <mpe@ellerman.id.au>2017-05-17 11:56:33 +1000
commitbfb9956ab4d8242f4594b5f4bee534b935384fd9 (patch)
tree9c51d8a21e963362e7705049d2a61acab84d6159 /arch
parentd04c02f8aa96d82e4cbe783f85a820aae820e746 (diff)
downloadlinux-bfb9956ab4d8242f4594b5f4bee534b935384fd9.tar.bz2
powerpc/mm: Fix crash in page table dump with huge pages
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. Cc: stable@vger.kernel.org # v4.10+ Fixes: 8eb07b187000 ("powerpc/mm: Dump linux pagetables") Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Diffstat (limited to 'arch')
-rw-r--r--arch/powerpc/mm/dump_linuxpagetables.c7
1 files changed, 4 insertions, 3 deletions
diff --git a/arch/powerpc/mm/dump_linuxpagetables.c b/arch/powerpc/mm/dump_linuxpagetables.c
index d659345a98d6..44fe4833910f 100644
--- 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>
@@ -391,7 +392,7 @@ static void walk_pmd(struct pg_state *st, pud_t *pud, unsigned long start)
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
@@ -407,7 +408,7 @@ static void walk_pud(struct pg_state *st, pgd_t *pgd, unsigned long start)
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
@@ -427,7 +428,7 @@ static void walk_pagetables(struct pg_state *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