mm: silence -Woverride-init/initializer-overrides

When compiling a kernel with W=1, there are several of those warnings due
to arm64 overriding a field on purpose.  Just disable those warnings for
both GCC and Clang of this file, so it will help dig "gems" hidden in the
W=1 warnings by reducing some noises.

mm/init-mm.c:39:2: warning: initializer overrides prior initialization
of this subobject [-Winitializer-overrides]
        INIT_MM_CONTEXT(init_mm)
        ^~~~~~~~~~~~~~~~~~~~~~~~
./arch/arm64/include/asm/mmu.h:133:9: note: expanded from macro
'INIT_MM_CONTEXT'
        .pgd = init_pg_dir,
               ^~~~~~~~~~~
mm/init-mm.c:30:10: note: previous initialization is here
        .pgd            = swapper_pg_dir,
                          ^~~~~~~~~~~~~~

Note: there is a side project trying to support explicitly allowing
specific initializer overrides in Clang, but there is no guarantee it
will happen or not.

https://github.com/ClangBuiltLinux/linux/issues/639

Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Qian Cai <[email protected]>
Cc: Nick Desaulniers <[email protected]>
Cc: Masahiro Yamada <[email protected]>
Cc: Mark Rutland <[email protected]>
Cc: Arnd Bergmann <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
This commit is contained in:
Qian Cai 2019-09-23 15:36:48 -07:00 • committed by Linus Torvalds
commit b57a775f51

View file

@ -21,6 +21,9 @@ KCOV_INSTRUMENT_memcontrol.o := n
KCOV_INSTRUMENT_mmzone.o := n
KCOV_INSTRUMENT_vmstat.o := n
CFLAGS_init-mm.o += $(call cc-disable-warning, override-init)
CFLAGS_init-mm.o += $(call cc-disable-warning, initializer-overrides)
mmu-y := nommu.o
mmu-$(CONFIG_MMU) := highmem.o memory.o mincore.o \
mlock.o mmap.o mmu_gather.o mprotect.o mremap.o \