From 1b8ca75eaaff2985709ad61cc33c77a673c75a8c Mon Sep 17 00:00:00 2001
From: =?utf8?q?Alejandro=20S=C3=A1ez?= <asm@redhat.com>
Date: Mon, 23 May 2022 12:07:47 +0000
Subject: [PATCH] runtime: fix breakpoint in ppc64x

Currently runtime.Breakpoint generates a SIGSEGV in ppc64.
The solution is an unconditional trap similar to what clang and gcc do. It is documented in the section C.6 of the ABI Book 3.

Fixes #52101

Change-Id: I071d2f2679b695ef268445b04c9222bd74e1f9af
GitHub-Last-Rev: fff4e5e8ffe23bf0cef135b22abd2cc0a3838613
GitHub-Pull-Request: golang/go#52102
Reviewed-on: https://go-review.googlesource.com/c/go/+/397554
Reviewed-by: Dmitri Shuralyov <dmitshur@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Paul Murphy <murp@ibm.com>
Run-TryBot: Paul Murphy <murp@ibm.com>
Reviewed-by: Cherry Mui <cherryyz@google.com>
---
 src/runtime/asm_ppc64x.s | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/runtime/asm_ppc64x.s b/src/runtime/asm_ppc64x.s
index ec17dc9ce3..c6bcf82ec0 100644
--- a/src/runtime/asm_ppc64x.s
+++ b/src/runtime/asm_ppc64x.s
@@ -106,7 +106,7 @@ DATA	runtime·mainPC+0(SB)/8,$runtime·main<ABIInternal>(SB)
 GLOBL	runtime·mainPC(SB),RODATA,$8
 
 TEXT runtime·breakpoint(SB),NOSPLIT|NOFRAME,$0-0
-	MOVD	R0, 0(R0) // TODO: TD
+	TW	$31, R0, R0
 	RET
 
 TEXT runtime·asminit(SB),NOSPLIT|NOFRAME,$0-0
-- 
2.48.1