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| author |   Martin Schwidefsky <schwidefsky@de.ibm.com> | 2019-04-10 15:48:43 +0200 |
|---|---|---|
| committer | Martin Schwidefsky <schwidefsky@de.ibm.com> | 2019-04-11 13:36:45 +0200 |
| commit | 7aa0055e06475f7b486c0673bc59c6478bc055fa (patch) | |
| tree | 646db629e908e27a0e133d612733cd643503a9f2 | |
| parent | s390/rseq: use trap4 for RSEQ_SIG (diff) | |
| download | linux-dev-7aa0055e06475f7b486c0673bc59c6478bc055fa.tar.xz linux-dev-7aa0055e06475f7b486c0673bc59c6478bc055fa.zip | |
s390: fine-tune stack switch helper
The CALL_ON_STACK helper currently does not work with clang and for
calls without arguments. It does not initialize r2 although the constraint
is "+&d". Rework the CALL_FMT_x and the CALL_ON_STACK macros to work
with clang and produce optimal code in all cases.
Reported-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
| -rw-r--r-- | arch/s390/include/asm/processor.h | 18 |
1 files changed, 9 insertions, 9 deletions
diff --git a/arch/s390/include/asm/processor.h b/arch/s390/include/asm/processor.h index 81038ab357ce..0ee022247580 100644 --- a/arch/s390/include/asm/processor.h +++ b/arch/s390/include/asm/processor.h @@ -261,12 +261,12 @@ static __no_kasan_or_inline unsigned short stap(void) CALL_ARGS_4(arg1, arg2, arg3, arg4); \ 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_2 CALL_FMT_1, "d" (r3) -#define CALL_FMT_3 CALL_FMT_2, "d" (r4) -#define CALL_FMT_4 CALL_FMT_3, "d" (r5) -#define CALL_FMT_5 CALL_FMT_4, "d" (r6) +#define CALL_FMT_0 "=&d" (r2) : +#define CALL_FMT_1 "+&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), +#define CALL_FMT_5 CALL_FMT_4 "d" (r6), #define CALL_CLOBBER_5 "0", "1", "14", "cc", "memory" #define CALL_CLOBBER_4 CALL_CLOBBER_5 @@ -286,10 +286,10 @@ static __no_kasan_or_inline unsigned short stap(void) " stg %[_prev],%[_bc](15)\n" \ " brasl 14,%[_fn]\n" \ " la 15,0(%[_prev])\n" \ - : "+&d" (r2), [_prev] "=&a" (prev) \ - : [_stack] "a" (stack), \ + : [_prev] "=&a" (prev), CALL_FMT_##nr \ + [_stack] "a" (stack), \ [_bc] "i" (offsetof(struct stack_frame, back_chain)), \ - [_fn] "X" (fn) CALL_FMT_##nr : CALL_CLOBBER_##nr); \ + [_fn] "X" (fn) : CALL_CLOBBER_##nr); \ r2; \ }) |