From: David Hildenbrand <david@redhat.com>
Date: Fri, 18 Oct 2019 20:19:23 -0700
Subject: mm/memory-failure.c: don't access uninitialized memmaps in
memory_failure()
Git-commit: 96c804a6ae8c59a9092b3d5dd581198472063184
Patch-mainline: 5.4-rc4
References: bnc#1151927 5.3.8
We should check for pfn_to_online_page() to not access uninitialized
memmaps. Reshuffle the code so we don't have to duplicate the error
message.
Link: http://lkml.kernel.org/r/20191009142435.3975-3-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Fixes: f1dd2cd13c4b ("mm, memory_hotplug: do not associate hotadded memory to zones until online") [visible after d0dc12e86b319]
Acked-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: <stable@vger.kernel.org> [4.13+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
---
mm/memory-failure.c | 14 ++++++++------
1 file changed, 8 insertions(+), 6 deletions(-)
--- a/mm/memory-failure.c
+++ b/mm/memory-failure.c
@@ -1257,17 +1257,19 @@ int memory_failure(unsigned long pfn, in
if (!sysctl_memory_failure_recovery)
panic("Memory failure on page %lx", pfn);
- if (!pfn_valid(pfn)) {
+ p = pfn_to_online_page(pfn);
+ if (!p) {
+ if (pfn_valid(pfn)) {
+ pgmap = get_dev_pagemap(pfn, NULL);
+ if (pgmap)
+ return memory_failure_dev_pagemap(pfn, flags,
+ pgmap);
+ }
pr_err("Memory failure: %#lx: memory outside kernel control\n",
pfn);
return -ENXIO;
}
- pgmap = get_dev_pagemap(pfn, NULL);
- if (pgmap)
- return memory_failure_dev_pagemap(pfn, flags, pgmap);
-
- p = pfn_to_page(pfn);
if (PageHuge(p))
return memory_failure_hugetlb(pfn, flags);
if (TestSetPageHWPoison(p)) {