RFR: 8367325: [s390x] build failure due to JDK-8361376 [v2]

[Amit Kumar]

On Wed, 17 Sep 2025 10:07:55 GMT, Martin Doerr <mdoerr at openjdk.org> wrote:

>> Now It is pointing to `z_cfi`: 
>> 
>> 
>> (gdb) x/i inst_addr 
>>    0x3ffe500017a:	cfi	%r0,0
>
> This line looks broken (already before this PR). Shouldn't it be something like `assert(Assembler::is_z_cfi...)`?

Will it be good to do something like this and get rid of `PATCHABLE_SEQ_START_OFFSET` ?: 


diff --git a/src/hotspot/cpu/s390/gc/shared/barrierSetNMethod_s390.cpp b/src/hotspot/cpu/s390/gc/shared/barrierSetNMethod_s390.cpp
index 4dc50232c17..807d3cdd899 100644
--- a/src/hotspot/cpu/s390/gc/shared/barrierSetNMethod_s390.cpp
+++ b/src/hotspot/cpu/s390/gc/shared/barrierSetNMethod_s390.cpp
@@ -38,10 +38,11 @@ class NativeMethodBarrier: public NativeInstruction {
     }
 
     address get_patchable_data_address() const {
+#ifdef ASSERT
       address inst_addr = get_barrier_start_address() + BarrierSetAssembler::PATCHABLE_SEQ_START_OFFSET;
-
-      DEBUG_ONLY(Assembler::is_z_cfi(*((long*)inst_addr)));
-      return inst_addr + 2;
+      assert(Assembler::is_z_cfi(*((long*)inst_addr)), "should be");
+#endif // ASSERT
+      return get_barrier_start_address() + BarrierSetAssembler::PATCHABLE_BARRIER_VALUE_OFFSET;
     }
 
   public:

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PR Review Comment: https://git.openjdk.org/jdk/pull/27213#discussion_r2355109142