Re: [PATCH RFC 4/7] riscv/vdso: don't clear PG_reserved

From: Palmer Dabbelt
Date: Fri Dec 07 2018 - 13:45:20 EST


On Wed, 05 Dec 2018 04:28:48 PST (-0800), david@xxxxxxxxxx wrote:
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.

Cc: Palmer Dabbelt <palmer@xxxxxxxxxx>
Cc: Albert Ou <aou@xxxxxxxxxxxxxxxxx>
Cc: Tobias Klauser <tklauser@xxxxxxxxxx>
Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Cc: Michal Hocko <mhocko@xxxxxxxxxx>
Cc: Matthew Wilcox <willy@xxxxxxxxxxxxx>
Signed-off-by: David Hildenbrand <david@xxxxxxxxxx>
---
arch/riscv/kernel/vdso.c | 1 -
1 file changed, 1 deletion(-)

diff --git a/arch/riscv/kernel/vdso.c b/arch/riscv/kernel/vdso.c
index 582cb153eb24..0cd044122234 100644
--- a/arch/riscv/kernel/vdso.c
+++ b/arch/riscv/kernel/vdso.c
@@ -54,7 +54,6 @@ static int __init vdso_init(void)
struct page *pg;

pg = virt_to_page(vdso_start + (i << PAGE_SHIFT));
- ClearPageReserved(pg);
vdso_pagelist[i] = pg;
}
vdso_pagelist[i] = virt_to_page(vdso_data);

I'm going to assume this will go in through another tree along with the rest of the set assuming everyone else is happy with it.

Acked-by: Palmer Dabbelt <palmer@xxxxxxxxxx>

Thanks!