From arnd@arndb.de  Wed Feb 21 10:34:37 2018
From: Arnd Bergmann <arnd@arndb.de>
Date: Thu, 15 Feb 2018 16:16:57 +0100
Subject: x86: fix build warnign with 32-bit PAE
To: stable@vger.kernel.org
Cc: x86@kernel.org, Dave Hansen <dave.hansen@linux.intel.com>, Ben Hutchings <ben.hutchings@codethink.co.uk>, Arnd Bergmann <arnd@arndb.de>, Greg Kroah-Hartman <gregkh@linuxfoundation.org>, Hugh Dickins <hughd@google.com>, Kees Cook <keescook@chromium.org>, linux-kernel@vger.kernel.org
Message-ID: <20180215151710.1473117-2-arnd@arndb.de>


I ran into a 4.9 build warning in randconfig testing, starting with the
KAISER patches:

arch/x86/kernel/ldt.c: In function 'alloc_ldt_struct':
arch/x86/include/asm/pgtable_types.h:208:24: error: large integer implicitly truncated to unsigned type [-Werror=overflow]
 #define __PAGE_KERNEL  (__PAGE_KERNEL_EXEC | _PAGE_NX)
                        ^
arch/x86/kernel/ldt.c:81:6: note: in expansion of macro '__PAGE_KERNEL'
      __PAGE_KERNEL);
      ^~~~~~~~~~~~~

I originally ran into this last year when the patches were part of linux-next,
and tried to work around it by using the proper 'pteval_t' types consistently,
but that caused additional problems.

This takes a much simpler approach, and makes the argument type of the dummy
helper always 64-bit, which is wide enough for any page table layout and
won't hurt since this call is just an empty stub anyway.

Fixes: 8f0baadf2bea ("kaiser: merged update")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Kees Cook <keescook@chromium.org>
Acked-by: Hugh Dickins <hughd@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 include/linux/kaiser.h |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/include/linux/kaiser.h
+++ b/include/linux/kaiser.h
@@ -32,7 +32,7 @@ static inline void kaiser_init(void)
 {
 }
 static inline int kaiser_add_mapping(unsigned long addr,
-				     unsigned long size, unsigned long flags)
+				     unsigned long size, u64 flags)
 {
 	return 0;
 }