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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-16 19:23:18 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-16 19:23:18 +0000
commit43a123c1ae6613b3efeed291fa552ecd909d3acf (patch)
treefd92518b7024bc74031f78a1cf9e454b65e73665 /src/runtime/tls_ppc64x.s
parentInitial commit. (diff)
downloadgolang-1.20-43a123c1ae6613b3efeed291fa552ecd909d3acf.tar.xz
golang-1.20-43a123c1ae6613b3efeed291fa552ecd909d3acf.zip
Adding upstream version 1.20.14.upstream/1.20.14upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'src/runtime/tls_ppc64x.s')
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1 files changed, 51 insertions, 0 deletions
diff --git a/src/runtime/tls_ppc64x.s b/src/runtime/tls_ppc64x.s
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+// Copyright 2014 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.
+
+//go:build ppc64 || ppc64le
+
+#include "go_asm.h"
+#include "go_tls.h"
+#include "funcdata.h"
+#include "textflag.h"
+
+// We have to resort to TLS variable to save g (R30).
+// 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 R30,
+// 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
+// ppc64 code that will overwrite this register.
+//
+// If !iscgo, this is a no-op.
+//
+// NOTE: setg_gcc<> assume this clobbers only R31.
+TEXT runtime·save_g(SB),NOSPLIT|NOFRAME,$0-0
+#ifndef GOOS_aix
+ MOVBZ runtime·iscgo(SB), R31
+ CMP R31, $0
+ BEQ nocgo
+#endif
+ MOVD runtime·tls_g(SB), R31
+ MOVD g, 0(R31)
+
+nocgo:
+ RET
+
+// load_g loads the g register from pthread-provided
+// thread-local memory, for use after calling externally compiled
+// ppc64 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 (R30), and R31.
+TEXT runtime·load_g(SB),NOSPLIT|NOFRAME,$0-0
+ MOVD runtime·tls_g(SB), R31
+ MOVD 0(R31), g
+ RET
+
+GLOBL runtime·tls_g+0(SB), TLSBSS+DUPOK, $8