sparc64: vdso: Use 32-bit CHECKFLAGS for compat vDSO

When building the compat vDSO the CHECKFLAGS from the 64-bit kernel
are used. These are combined with the 32-bit CFLAGS. This confuses
sparse, producing false-positive warnings or potentially missing
real issues.

Manually override the CHECKFLAGS for the compat vDSO with the correct
32-bit configuration.

Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@kernel.org>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Link: https://patch.msgid.link/20260302-vdso-compat-checkflags-v2-2-78e55baa58ba@linutronix.de
Closes: https://lore.kernel.org/lkml/202511030021.9v1mIgts-lkp@intel.com/

diff --git a/arch/sparc/vdso/Makefile b/arch/sparc/vdso/Makefile
index 683b2d40822447849d1b4a8e3f85d35dcf9d727e..d2811f17af078b513ed39406b099ae6d0b3767e7 100644 (file)
--- a/arch/sparc/vdso/Makefile
+++ b/arch/sparc/vdso/Makefile
@@ -90,6 +90,9 @@ KBUILD_CFLAGS_32 += -DDISABLE_BRANCH_PROFILING
 KBUILD_CFLAGS_32 += -mv8plus
 $(obj)/vdso32.so.dbg: KBUILD_CFLAGS = $(KBUILD_CFLAGS_32)
 
+CHECKFLAGS_32 := $(filter-out -m64 -D__sparc_v9__ -D__arch64__, $(CHECKFLAGS)) -m32
+$(obj)/vdso32.so.dbg: CHECKFLAGS = $(CHECKFLAGS_32)
+
 $(obj)/vdso32.so.dbg: FORCE \
                        $(obj)/vdso32/vdso32.lds \
                        $(obj)/vdso32/vclock_gettime.o \