On Wed, Mar 20, 2024 at 07:02:15PM +0100, Arnd Bergmann wrote:

From: Arnd Bergmann <arnd@arndb.de>

Both the vdso rework and the CONFIG_PAGE_SHIFT changes were merged during
the v6.9 merge window, so it is now possible to use CONFIG_PAGE_SHIFT
instead of including asm/page.h in the vdso.

This avoids the workaround for arm64 and addresses a build warning
for powerpc64:

In file included from <built-in>:4:
In file included from /home/arnd/arm-soc/arm-soc/lib/vdso/gettimeofday.c:5:
In file included from ../include/vdso/datapage.h:25:
arch/powerpc/include/asm/page.h:230:9: error: result of comparison of constant 13835058055282163712 with expression of type 'unsigned long' is always true [-Werror,-Wtautological-constant-out-of-range-compare]
  230 |         return __pa(kaddr) >> PAGE_SHIFT;
      |                ^~~~~~~~~~~
arch/powerpc/include/asm/page.h:217:37: note: expanded from macro '__pa'
  217 |         VIRTUAL_WARN_ON((unsigned long)(x) < PAGE_OFFSET);              \
      |         ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~
arch/powerpc/include/asm/page.h:202:73: note: expanded from macro 'VIRTUAL_WARN_ON'
  202 | #define VIRTUAL_WARN_ON(x)      WARN_ON(IS_ENABLED(CONFIG_DEBUG_VIRTUAL) && (x))
      |                                 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~
arch/powerpc/include/asm/bug.h:88:25: note: expanded from macro 'WARN_ON'
   88 |         int __ret_warn_on = !!(x);                              \
      |                                ^

Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: linuxppc-dev@lists.ozlabs.org
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Thomas Gleixner <redacted>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Anna-Maria Behnsen <anna-maria@linutronix.de>
See-also: 8b3843ae3634 ("vdso/datapage: Quick fix - use asm/page-def.h for ARM64")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

Thanks for tracking this!

Reviewed-by: Kees Cook <redacted>

-- 
Kees Cook