[PATCH v1 2/9] s390/vdso: don't clear PG_reserved

David Hildenbrand
2018-12-14T11:10:07Z

The VDSO is part of the kernel image and therefore the struct pages are
marked as reserved during boot.

As we install a special mapping, the actual struct pages will never be
exposed to MM via the page tables. We can therefore leave the pages
marked as reserved.

Suggested-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Mike Rapoport <rppt@linux.vnet.ibm.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Souptick Joarder <jrdr.linux@gmail.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Michal Hocko <mhocko@kernel.org>
Signed-off-by: David Hildenbrand <david@redhat.com>
---
arch/s390/kernel/vdso.c | 2 --
1 file changed, 2 deletions(-)

diff --git a/arch/s390/kernel/vdso.c b/arch/s390/kernel/vdso.c
index ebe748a9f472..9e24d23c26c0 100644
--- a/arch/s390/kernel/vdso.c
+++ b/arch/s390/kernel/vdso.c
@@ -292,7 +292,6 @@ static int __init vdso_init(void)
BUG_ON(vdso32_pagelist == NULL);
for (i = 0; i < vdso32_pages - 1; i++) {
struct page *pg = virt_to_page(vdso32_kbase + i*PAGE_SIZE);
- ClearPageReserved(pg);
get_page(pg);
vdso32_pagelist[i] = pg;
}
@@ -310,7 +309,6 @@ static int __init vdso_init(void)
BUG_ON(vdso64_pagelist == NULL);
for (i = 0; i < vdso64_pages - 1; i++) {
struct page *pg = virt_to_page(vdso64_kbase + i*PAGE_SIZE);
- ClearPageReserved(pg);
get_page(pg);
vdso64_pagelist[i] = pg;