8321972: test runtime/Unsafe/InternalErrorTest.java timeout on linux-riscv64 platform

Backport-of: e8768ae08dbee9c3e1ed01934142c03ffad5f349

Author: Olga Mikhaltsova

src/hotspot/cpu/riscv/assembler_riscv.hpp

@@ -2940,6 +2940,17 @@ enum Nf {
     return uabs(target - branch) < branch_range;
   }
 
+  // Decode the given instruction, checking if it's a 16-bit compressed
+  // instruction and return the address of the next instruction.
+  static address locate_next_instruction(address inst) {
+    // Instruction wider than 16 bits has the two least-significant bits set.
+    if ((0x3 & *inst) == 0x3) {
+      return inst + instruction_size;
+    } else {
+      return inst + compressed_instruction_size;
+    }
+  }
+
   Assembler(CodeBuffer* code) : AbstractAssembler(code), _in_compressible_region(true) {}
 };
 

src/hotspot/os_cpu/linux_riscv/os_linux_riscv.cpp

@@ -232,7 +232,7 @@ bool PosixSignals::pd_hotspot_signal_handler(int sig, siginfo_t* info,
         CompiledMethod* nm = (cb != nullptr) ? cb->as_compiled_method_or_null() : nullptr;
         bool is_unsafe_arraycopy = (thread->doing_unsafe_access() && UnsafeCopyMemory::contains_pc(pc));
         if ((nm != nullptr && nm->has_unsafe_access()) || is_unsafe_arraycopy) {
-          address next_pc = pc + NativeCall::instruction_size;
+          address next_pc = Assembler::locate_next_instruction(pc);
           if (is_unsafe_arraycopy) {
             next_pc = UnsafeCopyMemory::page_error_continue_pc(pc);
           }
@@ -271,7 +271,7 @@ bool PosixSignals::pd_hotspot_signal_handler(int sig, siginfo_t* info,
                 thread->thread_state() == _thread_in_native) &&
                 sig == SIGBUS && /* info->si_code == BUS_OBJERR && */
                 thread->doing_unsafe_access()) {
-      address next_pc = pc + NativeCall::instruction_size;
+      address next_pc = Assembler::locate_next_instruction(pc);
       if (UnsafeCopyMemory::contains_pc(pc)) {
         next_pc = UnsafeCopyMemory::page_error_continue_pc(pc);
       }