[PATCH 12/12] [PROBABLY WRONG] s390: void '0' constraint in inline assembly

Arnd Bergmann
2019-04-08T21:26:25Z

clang does not understand the contraint "0" in the CALL_ON_STACK()
macro:

../arch/s390/mm/maccess.c:117:10: error: invalid input constraint '0' in asm
return CALL_ON_STACK(_memcpy_real, S390_lowcore.nodat_stack,
^
../arch/s390/include/asm/processor.h:292:20: note: expanded from macro 'CALL_ON_STACK'
[_fn] "X" (fn) CALL_FMT_##nr : CALL_CLOBBER_##nr); \
^
<scratch space>:207:1: note: expanded from here
CALL_FMT_3
^
../arch/s390/include/asm/processor.h:267:20: note: expanded from macro 'CALL_FMT_3'
#define CALL_FMT_3 CALL_FMT_2, "d" (r4)
^
../arch/s390/include/asm/processor.h:266:20: note: expanded from macro 'CALL_FMT_2'
#define CALL_FMT_2 CALL_FMT_1, "d" (r3)
^
../arch/s390/include/asm/processor.h:265:32: note: expanded from macro 'CALL_FMT_1'
#define CALL_FMT_1 CALL_FMT_0, "0" (r2)
^

I don't know what the correct fix here would be, changing it to "d" made
it build, since clang does understand this one.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
arch/s390/include/asm/processor.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/s390/include/asm/processor.h b/arch/s390/include/asm/processor.h
index 700c650ffd4f..84c59c99668a 100644
--- a/arch/s390/include/asm/processor.h
+++ b/arch/s390/include/asm/processor.h
@@ -262,7 +262,7 @@ static __no_kasan_or_inline unsigned short stap(void)
register unsigned long r4 asm("6") = (unsigned long)(arg5)

#define CALL_FMT_0
-#define CALL_FMT_1 CALL_FMT_0, "0" (r2)
+#define CALL_FMT_1 CALL_FMT_0, "d" (r2)
#define CALL_FMT_2 CALL_FMT_1, "d" (r3)
#define CALL_FMT_3 CALL_FMT_2, "d" (r4)
#define CALL_FMT_4 CALL_FMT_3, "d" (r5)
--
2.20.0