[PATCH v2 2/9] s390/vdso: don't clear PG_reserved

David Hildenbrand david at redhat.com
Mon Jan 14 23:58:56 AEDT 2019


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 at de.ibm.com>
Cc: Martin Schwidefsky <schwidefsky at de.ibm.com>
Cc: Heiko Carstens <heiko.carstens at de.ibm.com>
Cc: Matthew Wilcox <willy at infradead.org>
Cc: Mike Rapoport <rppt at linux.vnet.ibm.com>
Cc: Michal Hocko <mhocko at suse.com>
Cc: Vasily Gorbik <gor at linux.ibm.com>
Cc: Kees Cook <keescook at chromium.org>
Cc: Souptick Joarder <jrdr.linux at gmail.com>
Cc: Andrew Morton <akpm at linux-foundation.org>
Cc: Michal Hocko <mhocko at kernel.org>
Signed-off-by: David Hildenbrand <david at 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 4ff354887db4..e7920a68a12e 100644
--- a/arch/s390/kernel/vdso.c
+++ b/arch/s390/kernel/vdso.c
@@ -291,7 +291,6 @@ 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;
 	}
@@ -309,7 +308,6 @@ 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;
 	}
-- 
2.17.2



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