[PATCH for 5.2 05/12] rseq/selftests: s390: use jg instruction for jumps outside of the asm

Mathieu Desnoyers
2019-04-29T15:30:26Z

The branch target range of the "j" instruction is 64K, which is not
enough for the general case.

Suggested-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
CC: Thomas Gleixner <tglx@linutronix.de>
CC: Joel Fernandes <joelaf@google.com>
CC: Peter Zijlstra <peterz@infradead.org>
CC: Catalin Marinas <catalin.marinas@arm.com>
CC: Dave Watson <davejwatson@fb.com>
CC: Will Deacon <will.deacon@arm.com>
CC: Shuah Khan <shuah@kernel.org>
CC: Andi Kleen <andi@firstfloor.org>
CC: linux-kselftest@vger.kernel.org
CC: "H . Peter Anvin" <hpa@zytor.com>
CC: Chris Lameter <cl@linux.com>
CC: Russell King <linux@arm.linux.org.uk>
CC: Michael Kerrisk <mtk.manpages@gmail.com>
CC: "Paul E . McKenney" <paulmck@linux.vnet.ibm.com>
CC: Paul Turner <pjt@google.com>
CC: Boqun Feng <boqun.feng@gmail.com>
CC: Josh Triplett <josh@joshtriplett.org>
CC: Steven Rostedt <rostedt@goodmis.org>
CC: Ben Maurer <bmaurer@fb.com>
CC: linux-api@vger.kernel.org
CC: Andy Lutomirski <luto@amacapital.net>
CC: Andrew Morton <akpm@linux-foundation.org>
CC: Linus Torvalds <torvalds@linux-foundation.org>
---
tools/testing/selftests/rseq/rseq-s390.h | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/tools/testing/selftests/rseq/rseq-s390.h b/tools/testing/selftests/rseq/rseq-s390.h
index fbb97815d71c..7c4f3a70b6c7 100644
--- a/tools/testing/selftests/rseq/rseq-s390.h
+++ b/tools/testing/selftests/rseq/rseq-s390.h
@@ -117,14 +117,14 @@ do { \
".long " __rseq_str(RSEQ_SIG) "\n\t" \
__rseq_str(label) ":\n\t" \
teardown \
- "j %l[" __rseq_str(abort_label) "]\n\t" \
+ "jg %l[" __rseq_str(abort_label) "]\n\t" \
".popsection\n\t"

#define RSEQ_ASM_DEFINE_CMPFAIL(label, teardown, cmpfail_label) \
".pushsection __rseq_failure, \"ax\"\n\t" \
__rseq_str(label) ":\n\t" \
teardown \
- "j %l[" __rseq_str(cmpfail_label) "]\n\t" \
+ "jg %l[" __rseq_str(cmpfail_label) "]\n\t" \
".popsection\n\t"

static inline __attribute__((always_inline))
--
2.11.0