[PATCH 3.16 76/76] x86: fix build warnign with 32-bit PAE

From: Ben Hutchings
Date: Sun Mar 11 2018 - 23:13:41 EST


3.16.56-rc1 review patch. If anyone has any objections, please let me know.

------------------

From: Arnd Bergmann <arnd@xxxxxxxx>

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@xxxxxxxx>
Acked-by: Kees Cook <keescook@xxxxxxxxxxxx>
Acked-by: Hugh Dickins <hughd@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
---
include/linux/kaiser.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/include/linux/kaiser.h b/include/linux/kaiser.h
index 58c55b1589d0..b56c19010480 100644
--- 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;
}