From: Qian Cai <cai@xxxxxx>
Subject: include/asm-generic/5level-fixup.h: fix variable 'p4d' set but not used
A compiler throws a warning on an arm64 system since commit 9849a5697d3d
("arch, mm: convert all architectures to use 5level-fixup.h"),
mm/kasan/init.c: In function 'kasan_free_p4d':
mm/kasan/init.c:344:9: warning: variable 'p4d' set but not used
[-Wunused-but-set-variable]
p4d_t *p4d;
^~~
because p4d_none() in "5level-fixup.h" is compiled away while it is a
static inline function in "pgtable-nopud.h". However, if converted
p4d_none() to a static inline there, powerpc would be unhappy as it reads
those in assembler language in
"arch/powerpc/include/asm/book3s/64/pgtable.h", so it needs to skip
assembly include for the static inline C function. While at it, converted
a few similar functions to be consistent with the ones in
"pgtable-nopud.h".
Link: http://lkml.kernel.org/r/20190806232917.881-1-cai@xxxxxx
Signed-off-by: Qian Cai <cai@xxxxxx>
Acked-by: Arnd Bergmann <arnd@xxxxxxxx>
Cc: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx>
Cc: Michal Hocko <mhocko@xxxxxxxx>
Cc: Jason Gunthorpe <jgg@xxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
include/asm-generic/5level-fixup.h | 21 ++++++++++++++++++---
1 file changed, 18 insertions(+), 3 deletions(-)
--- a/include/asm-generic/5level-fixup.h~asm-generic-fix-variable-p4d-set-but-not-used
+++ a/include/asm-generic/5level-fixup.h
@@ -19,9 +19,24 @@
#define p4d_alloc(mm, pgd, address) (pgd)
#define p4d_offset(pgd, start) (pgd)
-#define p4d_none(p4d) 0
-#define p4d_bad(p4d) 0
-#define p4d_present(p4d) 1
+
+#ifndef __ASSEMBLY__
+static inline int p4d_none(p4d_t p4d)
+{
+ return 0;
+}
+
+static inline int p4d_bad(p4d_t p4d)
+{
+ return 0;
+}
+
+static inline int p4d_present(p4d_t p4d)
+{
+ return 1;
+}
+#endif
+
#define p4d_ERROR(p4d) do { } while (0)
#define p4d_clear(p4d) pgd_clear(p4d)
#define p4d_val(p4d) pgd_val(p4d)
_
