[tip: timers/vdso] sparc64: vdso: Use 32-bit CHECKFLAGS for compat vDSO

[tip-bot2 for Thomas Weißschuh]

The following commit has been merged into the timers/vdso branch of tip:

Commit-ID:     273aaa8ef8e347c08865effcd8917e20f049e612
Gitweb:        https://git.kernel.org/tip/273aaa8ef8e347c08865effcd8917e20f049e612
Author:        Thomas Weißschuh <thomas.weissschuh@xxxxxxxxxxxxx>
AuthorDate:    Mon, 02 Mar 2026 08:58:38 +01:00
Committer:     Thomas Gleixner <tglx@xxxxxxxxxx>
CommitterDate: Wed, 11 Mar 2026 10:15:42 +01:00

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@xxxxxxxxx>
Signed-off-by: Thomas Weißschuh <thomas.weissschuh@xxxxxxxxxxxxx>
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxx>
Acked-by: Arnd Bergmann <arnd@xxxxxxxx>
Link: https://patch.msgid.link/20260302-vdso-compat-checkflags-v2-2-78e55baa58ba@xxxxxxxxxxxxx
Closes: https://lore.kernel.org/lkml/202511030021.9v1mIgts-lkp@xxxxxxxxx/
---
 arch/sparc/vdso/Makefile | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/arch/sparc/vdso/Makefile b/arch/sparc/vdso/Makefile
index 683b2d4..d2811f1 100644
--- 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 \