From: Vladimir Petko <vladimir.petko@canonical.com>
Date: Wed, 22 Jul 2026 00:23:02 +0000 (+1200)
Subject: disable UnsafeGuard in Unsafe_SetMemory0 for i386
X-Git-Tag: archive/raspbian/25.0.5_7ea-1+rpi1~3^2~9
X-Git-Url: https://dgit.raspbian.org/?a=commitdiff_plain;h=14bd22a50d0562d6da7d86ff5e24b9a74b16eb80;p=openjdk-25.git

disable UnsafeGuard in Unsafe_SetMemory0 for i386

Bug: https://bugs.openjdk.org/browse/JDK-8335238
Forwarded: not-needed
Last-Update: 2024-07-01

x86 hotspot aseembler incorrectly returns next instruction's PC
for rep stos %eax,%es:(%edi) causing an infinite loop.
This patch removes UnsafeGuard for i386, so that VM crashes
instead of hanging indefinitely.
Patch should not be forwarded as it reverses JDK-8320886 for
i386.

Gbp-Pq: Name jdk-8335238-workaround.patch
---

diff --git a/src/hotspot/share/prims/unsafe.cpp b/src/hotspot/share/prims/unsafe.cpp
index a6300e814..d173b3fa7 100644
--- a/src/hotspot/share/prims/unsafe.cpp
+++ b/src/hotspot/share/prims/unsafe.cpp
@@ -391,7 +391,9 @@ UNSAFE_ENTRY_SCOPED(void, Unsafe_SetMemory0(JNIEnv *env, jobject unsafe, jobject
   void* p = index_oop_from_field_offset_long(base, offset);
 
   {
+#if !defined(IA32) || !defined(TARGET_ARCH_x86)
     GuardUnsafeAccess guard(thread);
+#endif
     if (StubRoutines::unsafe_setmemory() != nullptr) {
       MACOS_AARCH64_ONLY(ThreadWXEnable wx(WXExec, thread));
       StubRoutines::UnsafeSetMemory_stub()(p, sz, value);