From: Vasily Gorbik gor@linux.ibm.com
[ Upstream commit b6cbe3e8bdff6f21f1b58b08a55f479cdcf98282 ]
Kasan instrumentation adds "store" check for variables marked as modified by inline assembly. With user pointers containing addresses from another address space this produces false positives.
static inline unsigned long clear_user_xc(void __user *to, ...) { asm volatile( ... : "+a" (to) ...
User space access functions are wrapped by manually instrumented functions in kasan common code, which should be sufficient to catch errors. So, we just disable uaccess.o instrumentation altogether.
Reviewed-by: Martin Schwidefsky schwidefsky@de.ibm.com Signed-off-by: Vasily Gorbik gor@linux.ibm.com Signed-off-by: Martin Schwidefsky schwidefsky@de.ibm.com Signed-off-by: Sasha Levin sashal@kernel.org --- arch/s390/lib/Makefile | 4 ++++ 1 file changed, 4 insertions(+)
diff --git a/arch/s390/lib/Makefile b/arch/s390/lib/Makefile index 57ab40188d4bd..5418d10dc2a81 100644 --- a/arch/s390/lib/Makefile +++ b/arch/s390/lib/Makefile @@ -9,5 +9,9 @@ lib-$(CONFIG_SMP) += spinlock.o lib-$(CONFIG_KPROBES) += probes.o lib-$(CONFIG_UPROBES) += probes.o
+# Instrumenting memory accesses to __user data (in different address space) +# produce false positives +KASAN_SANITIZE_uaccess.o := n + chkbss := mem.o include $(srctree)/arch/s390/scripts/Makefile.chkbss