powerpc/vdso: don't clear PG_reserved

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.

Link: http://lkml.kernel.org/r/20190114125903.24845-4-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Acked-by: Michael Ellerman <mpe@ellerman.id.au>		[powerpc]
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Christophe Leroy <christophe.leroy@c-s.fr>
Cc: Kees Cook <keescook@chromium.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/arch/powerpc/kernel/vdso.c b/arch/powerpc/kernel/vdso.c
index 7725a97..a31b623 100644 (file)
--- a/arch/powerpc/kernel/vdso.c
+++ b/arch/powerpc/kernel/vdso.c
@@ -798,7 +798,6 @@ static int __init vdso_init(void)
        BUG_ON(vdso32_pagelist == NULL);
        for (i = 0; i < vdso32_pages; i++) {
                struct page *pg = virt_to_page(vdso32_kbase + i*PAGE_SIZE);
-               ClearPageReserved(pg);
                get_page(pg);
                vdso32_pagelist[i] = pg;
        }
@@ -812,7 +811,6 @@ static int __init vdso_init(void)
        BUG_ON(vdso64_pagelist == NULL);
        for (i = 0; i < vdso64_pages; i++) {
                struct page *pg = virt_to_page(vdso64_kbase + i*PAGE_SIZE);
-               ClearPageReserved(pg);
                get_page(pg);
                vdso64_pagelist[i] = pg;
        }