From: Arnd Bergmann <arnd@arndb.de>

The recent change to the vdso_data_store broke building compat VDSO
on at least arm64 because it includes headers outside of the include/vdso/
namespace:

In file included from arch/arm64/include/asm/lse.h:5,
                 from arch/arm64/include/asm/cmpxchg.h:14,
                 from arch/arm64/include/asm/atomic.h:16,
                 from include/linux/atomic.h:7,
                 from include/asm-generic/bitops/atomic.h:5,
                 from arch/arm64/include/asm/bitops.h:25,
                 from include/linux/bitops.h:68,
                 from arch/arm64/include/asm/memory.h:209,
                 from arch/arm64/include/asm/page.h:46,
                 from include/vdso/datapage.h:22,
                 from lib/vdso/gettimeofday.c:5,
                 from <command-line>:
arch/arm64/include/asm/atomic_ll_sc.h:298:9: error: unknown type name 'u128'
  298 |         u128 full;

Use an open-coded page size calculation based on the new CONFIG_PAGE_SHIFT
Kconfig symbol instead.

Reported-by: Linux Kernel Functional Testing <redacted>
Fixes: a0d2fcd62ac2 ("vdso/ARM: Make union vdso_data_store available for all architectures")
Link: https://lore.kernel.org/lkml/CA+G9fYtrXXm_KO9fNPz3XaRxHV7UD_yQp-TEuPQrNRHU+_0W_Q@mail.gmail.com/ (local)
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
 include/vdso/datapage.h | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/include/vdso/datapage.h b/include/vdso/datapage.h
index 7ba44379a095..2c39a67d7e23 100644
--- a/include/vdso/datapage.h
+++ b/include/vdso/datapage.h

@@ -19,8 +19,6 @@
 #include <vdso/time32.h>
 #include <vdso/time64.h>
 
-#include <asm/page.h>
-
 #ifdef CONFIG_ARCH_HAS_VDSO_DATA
 #include <asm/vdso/data.h>
 #else

@@ -128,7 +126,7 @@ extern struct vdso_data _timens_data[CS_BASES] __attribute__((visibility("hidden
  */
 union vdso_data_store {
 	struct vdso_data	data[CS_BASES];
-	u8			page[PAGE_SIZE];
+	u8			page[1ul << CONFIG_PAGE_SHIFT];
 };
 
 /*

-- 
2.39.2