[release/9.0] [mono] Fix crash in emit_llvmonly_handler_start (#107590)

* Fix crash in emit_llvmonly_handler_start Do not try to emit branch when target_bb is not set * Feedback --------- Co-authored-by: Radek Doulik <[email protected]> Co-authored-by: Larry Ewing <[email protected]> Co-authored-by: Jeff Schwartz <[email protected]>
dotnet · Sep 16, 2024 · e6a4f1b · e6a4f1b
1 parent 3de60e8
commit e6a4f1b
Showing 1 changed file with 18 additions and 5 deletions.
diff --git a/src/mono/mono/mini/mini-llvm.c b/src/mono/mono/mini/mini-llvm.c
@@ -5617,6 +5617,17 @@ scalar_op_from_vector_op_process_result (ScalarOpFromVectorOpCtx *sctx, LLVMValu
  return vector_from_scalar (sctx->ctx, sctx->return_type, result);
 }
 
+static gboolean bb_needs_call_handler_target(MonoBasicBlock *bb, EmitContext *ctx)
+{
+ if (ctx->cfg->interp_entry_only || !(bb->region != -1 && (bb->flags & BB_EXCEPTION_HANDLER)))
+ return FALSE;
+
+ if (ctx->cfg->deopt && MONO_REGION_FLAGS (bb->region) == MONO_EXCEPTION_CLAUSE_FILTER)
+ return FALSE;
+
+ return TRUE;
+}
+
 static void
 emit_llvmonly_handler_start (EmitContext *ctx, MonoBasicBlock *bb, LLVMBasicBlockRef cbb)
 {
@@ -5636,8 +5647,13 @@ emit_llvmonly_handler_start (EmitContext *ctx, MonoBasicBlock *bb, LLVMBasicBloc
  }
  }
 
- LLVMBuilderRef handler_builder = create_builder (ctx);
  LLVMBasicBlockRef target_bb = ctx->bblocks [bb->block_num].call_handler_target_bb;
+ if (!target_bb) {
+ g_assert(!bb_needs_call_handler_target (bb, ctx));
+ return;
+ }
+
+ LLVMBuilderRef handler_builder = create_builder (ctx);
  LLVMPositionBuilderAtEnd (handler_builder, target_bb);
 
  // Make the handler code end with a jump to cbb
@@ -13406,10 +13422,7 @@ emit_method_inner (EmitContext *ctx)
  int clause_index;
  char name [128];
 
- if (ctx->cfg->interp_entry_only || !(bb->region != -1 && (bb->flags & BB_EXCEPTION_HANDLER)))
- continue;
-
- if (ctx->cfg->deopt && MONO_REGION_FLAGS (bb->region) == MONO_EXCEPTION_CLAUSE_FILTER)
+ if (!bb_needs_call_handler_target(bb, ctx))
  continue;
 
  clause_index = MONO_REGION_CLAUSE_INDEX (bb->region);