Adding upstream version 1.21.8.upstream/1.21.8

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 51 insertions, 0 deletions

diff --git a/src/runtime/tls_s390x.s b/src/runtime/tls_s390x.s
new file mode 100644
index 0000000..cb6a21c
--- /dev/null
+++ b/src/runtime/tls_s390x.s
@@ -0,0 +1,51 @@
+// Copyright 2016 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+#include "go_asm.h"
+#include "go_tls.h"
+#include "funcdata.h"
+#include "textflag.h"
+
+// We have to resort to TLS variable to save g (R13).
+// One reason is that external code might trigger
+// SIGSEGV, and our runtime.sigtramp don't even know we
+// are in external code, and will continue to use R13,
+// this might well result in another SIGSEGV.
+
+// save_g saves the g register into pthread-provided
+// thread-local memory, so that we can call externally compiled
+// s390x code that will overwrite this register.
+//
+// If !iscgo, this is a no-op.
+//
+// NOTE: setg_gcc<> assume this clobbers only R10 and R11.
+TEXT runtime·save_g(SB),NOSPLIT|NOFRAME,$0-0
+	MOVB	runtime·iscgo(SB),  R10
+	CMPBEQ	R10, $0, nocgo
+	MOVW	AR0, R11
+	SLD	$32, R11
+	MOVW	AR1, R11
+	MOVD	runtime·tls_g(SB), R10
+	MOVD	g, 0(R10)(R11*1)
+nocgo:
+	RET
+
+// load_g loads the g register from pthread-provided
+// thread-local memory, for use after calling externally compiled
+// s390x code that overwrote those registers.
+//
+// This is never called directly from C code (it doesn't have to
+// follow the C ABI), but it may be called from a C context, where the
+// usual Go registers aren't set up.
+//
+// NOTE: _cgo_topofstack assumes this only clobbers g (R13), R10 and R11.
+TEXT runtime·load_g(SB),NOSPLIT|NOFRAME,$0-0
+	MOVW	AR0, R11
+	SLD	$32, R11
+	MOVW	AR1, R11
+	MOVD	runtime·tls_g(SB), R10
+	MOVD	0(R10)(R11*1), g
+	RET
+
+GLOBL runtime·tls_g+0(SB),TLSBSS,$8