[PATCH 12/28] x86: vdso: Place vdso_data at beginning of vvar page

From: Thomas Weißschuh
Date: Thu Oct 10 2024 - 03:05:36 EST


The offset of the vdso_data only has historic reasons, as back then
other vvars also existed and offset 0 was already used.
(See commit 8c49d9a74bac ("x86-64: Clean up vdso/kernel shared variables"))
Over time most other vvars got removed and offset 0 is free again.

Moving vdso_data to the beginning of the vvar page aligns x86 with other
architectures and opens up the way for the removal of the custom x86
vvar machinery.

Signed-off-by: Thomas Weißschuh <thomas.weissschuh@xxxxxxxxxxxxx>
---
arch/x86/include/asm/vvar.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/include/asm/vvar.h b/arch/x86/include/asm/vvar.h
index 9d9af37f7cab9e3e6159c0b758e500ddcfc6b3e8..01e60e0f671e9625669dc8fdacf3cdddf8cbf4fb 100644
--- a/arch/x86/include/asm/vvar.h
+++ b/arch/x86/include/asm/vvar.h
@@ -58,7 +58,7 @@ extern char __vvar_page;

/* DECLARE_VVAR(offset, type, name) */

-DECLARE_VVAR(128, struct vdso_data, _vdso_data)
+DECLARE_VVAR(0, struct vdso_data, _vdso_data)

#if !defined(_SINGLE_DATA)
#define _SINGLE_DATA

--
2.47.0