The patch below does not apply to the 4.4-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From dbfee5aee7e54f83d96ceb8e3e80717fac62ad63 Mon Sep 17 00:00:00 2001
From: Mike Kravetz <mike.kravetz(a)oracle.com>
Date: Wed, 24 Feb 2021 12:07:50 -0800
Subject: [PATCH] hugetlb: fix update_and_free_page contig page struct
assumption
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
page structs are not guaranteed to be contiguous for gigantic pages. The
routine update_and_free_page can encounter a gigantic page, yet it assumes
page structs are contiguous when setting page flags in subpages.
If update_and_free_page encounters non-contiguous page structs, we can see
“BUG: Bad page state in process …” errors.
Non-contiguous page structs are generally not an issue. However, they can
exist with a specific kernel configuration and hotplug operations. For
example: Configure the kernel with CONFIG_SPARSEMEM and
!CONFIG_SPARSEMEM_VMEMMAP. Then, hotplug add memory for the area where
the gigantic page will be allocated. Zi Yan outlined steps to reproduce
here [1].
[1] https://lore.kernel.org/linux-mm/16F7C58B-4D79-41C5-9B64-A1A1628F4AF2@nvidi…
Link: https://lkml.kernel.org/r/20210217184926.33567-1-mike.kravetz@oracle.com
Fixes: 944d9fec8d7a ("hugetlb: add support for gigantic page allocation at runtime")
Signed-off-by: Zi Yan <ziy(a)nvidia.com>
Signed-off-by: Mike Kravetz <mike.kravetz(a)oracle.com>
Cc: Zi Yan <ziy(a)nvidia.com>
Cc: Davidlohr Bueso <dbueso(a)suse.de>
Cc: "Kirill A . Shutemov" <kirill.shutemov(a)linux.intel.com>
Cc: Andrea Arcangeli <aarcange(a)redhat.com>
Cc: Matthew Wilcox <willy(a)infradead.org>
Cc: Oscar Salvador <osalvador(a)suse.de>
Cc: Joao Martins <joao.m.martins(a)oracle.com>
Cc: <stable(a)vger.kernel.org>
Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds(a)linux-foundation.org>
diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 6786b313e6ac..3f6a50373d4f 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -1321,14 +1321,16 @@ static inline void destroy_compound_gigantic_page(struct page *page,
static void update_and_free_page(struct hstate *h, struct page *page)
{
int i;
+ struct page *subpage = page;
if (hstate_is_gigantic(h) && !gigantic_page_runtime_supported())
return;
h->nr_huge_pages--;
h->nr_huge_pages_node[page_to_nid(page)]--;
- for (i = 0; i < pages_per_huge_page(h); i++) {
- page[i].flags &= ~(1 << PG_locked | 1 << PG_error |
+ for (i = 0; i < pages_per_huge_page(h);
+ i++, subpage = mem_map_next(subpage, page, i)) {
+ subpage->flags &= ~(1 << PG_locked | 1 << PG_error |
1 << PG_referenced | 1 << PG_dirty |
1 << PG_active | 1 << PG_private |
1 << PG_writeback);
The patch below does not apply to the 4.9-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From dbfee5aee7e54f83d96ceb8e3e80717fac62ad63 Mon Sep 17 00:00:00 2001
From: Mike Kravetz <mike.kravetz(a)oracle.com>
Date: Wed, 24 Feb 2021 12:07:50 -0800
Subject: [PATCH] hugetlb: fix update_and_free_page contig page struct
assumption
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
page structs are not guaranteed to be contiguous for gigantic pages. The
routine update_and_free_page can encounter a gigantic page, yet it assumes
page structs are contiguous when setting page flags in subpages.
If update_and_free_page encounters non-contiguous page structs, we can see
“BUG: Bad page state in process …” errors.
Non-contiguous page structs are generally not an issue. However, they can
exist with a specific kernel configuration and hotplug operations. For
example: Configure the kernel with CONFIG_SPARSEMEM and
!CONFIG_SPARSEMEM_VMEMMAP. Then, hotplug add memory for the area where
the gigantic page will be allocated. Zi Yan outlined steps to reproduce
here [1].
[1] https://lore.kernel.org/linux-mm/16F7C58B-4D79-41C5-9B64-A1A1628F4AF2@nvidi…
Link: https://lkml.kernel.org/r/20210217184926.33567-1-mike.kravetz@oracle.com
Fixes: 944d9fec8d7a ("hugetlb: add support for gigantic page allocation at runtime")
Signed-off-by: Zi Yan <ziy(a)nvidia.com>
Signed-off-by: Mike Kravetz <mike.kravetz(a)oracle.com>
Cc: Zi Yan <ziy(a)nvidia.com>
Cc: Davidlohr Bueso <dbueso(a)suse.de>
Cc: "Kirill A . Shutemov" <kirill.shutemov(a)linux.intel.com>
Cc: Andrea Arcangeli <aarcange(a)redhat.com>
Cc: Matthew Wilcox <willy(a)infradead.org>
Cc: Oscar Salvador <osalvador(a)suse.de>
Cc: Joao Martins <joao.m.martins(a)oracle.com>
Cc: <stable(a)vger.kernel.org>
Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds(a)linux-foundation.org>
diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 6786b313e6ac..3f6a50373d4f 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -1321,14 +1321,16 @@ static inline void destroy_compound_gigantic_page(struct page *page,
static void update_and_free_page(struct hstate *h, struct page *page)
{
int i;
+ struct page *subpage = page;
if (hstate_is_gigantic(h) && !gigantic_page_runtime_supported())
return;
h->nr_huge_pages--;
h->nr_huge_pages_node[page_to_nid(page)]--;
- for (i = 0; i < pages_per_huge_page(h); i++) {
- page[i].flags &= ~(1 << PG_locked | 1 << PG_error |
+ for (i = 0; i < pages_per_huge_page(h);
+ i++, subpage = mem_map_next(subpage, page, i)) {
+ subpage->flags &= ~(1 << PG_locked | 1 << PG_error |
1 << PG_referenced | 1 << PG_dirty |
1 << PG_active | 1 << PG_private |
1 << PG_writeback);
The patch below does not apply to the 4.14-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From dbfee5aee7e54f83d96ceb8e3e80717fac62ad63 Mon Sep 17 00:00:00 2001
From: Mike Kravetz <mike.kravetz(a)oracle.com>
Date: Wed, 24 Feb 2021 12:07:50 -0800
Subject: [PATCH] hugetlb: fix update_and_free_page contig page struct
assumption
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
page structs are not guaranteed to be contiguous for gigantic pages. The
routine update_and_free_page can encounter a gigantic page, yet it assumes
page structs are contiguous when setting page flags in subpages.
If update_and_free_page encounters non-contiguous page structs, we can see
“BUG: Bad page state in process …” errors.
Non-contiguous page structs are generally not an issue. However, they can
exist with a specific kernel configuration and hotplug operations. For
example: Configure the kernel with CONFIG_SPARSEMEM and
!CONFIG_SPARSEMEM_VMEMMAP. Then, hotplug add memory for the area where
the gigantic page will be allocated. Zi Yan outlined steps to reproduce
here [1].
[1] https://lore.kernel.org/linux-mm/16F7C58B-4D79-41C5-9B64-A1A1628F4AF2@nvidi…
Link: https://lkml.kernel.org/r/20210217184926.33567-1-mike.kravetz@oracle.com
Fixes: 944d9fec8d7a ("hugetlb: add support for gigantic page allocation at runtime")
Signed-off-by: Zi Yan <ziy(a)nvidia.com>
Signed-off-by: Mike Kravetz <mike.kravetz(a)oracle.com>
Cc: Zi Yan <ziy(a)nvidia.com>
Cc: Davidlohr Bueso <dbueso(a)suse.de>
Cc: "Kirill A . Shutemov" <kirill.shutemov(a)linux.intel.com>
Cc: Andrea Arcangeli <aarcange(a)redhat.com>
Cc: Matthew Wilcox <willy(a)infradead.org>
Cc: Oscar Salvador <osalvador(a)suse.de>
Cc: Joao Martins <joao.m.martins(a)oracle.com>
Cc: <stable(a)vger.kernel.org>
Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds(a)linux-foundation.org>
diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 6786b313e6ac..3f6a50373d4f 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -1321,14 +1321,16 @@ static inline void destroy_compound_gigantic_page(struct page *page,
static void update_and_free_page(struct hstate *h, struct page *page)
{
int i;
+ struct page *subpage = page;
if (hstate_is_gigantic(h) && !gigantic_page_runtime_supported())
return;
h->nr_huge_pages--;
h->nr_huge_pages_node[page_to_nid(page)]--;
- for (i = 0; i < pages_per_huge_page(h); i++) {
- page[i].flags &= ~(1 << PG_locked | 1 << PG_error |
+ for (i = 0; i < pages_per_huge_page(h);
+ i++, subpage = mem_map_next(subpage, page, i)) {
+ subpage->flags &= ~(1 << PG_locked | 1 << PG_error |
1 << PG_referenced | 1 << PG_dirty |
1 << PG_active | 1 << PG_private |
1 << PG_writeback);