Reorder frame invoke logic for safety

The call stack entry needs to be sufficiently set up before we try to GC mark it. Sending spesh log entries can cause us to enter GC. Make sure we have set code_ref and outer before that can ever happen, so that we don't mark leftover junk pointers.
MoarVM · Jun 29, 2020 · 008d4af · 008d4af
1 parent 2b52b73
commit 008d4af
Showing 1 changed file with 8 additions and 12 deletions.
diff --git a/src/core/frame.c b/src/core/frame.c
@@ -570,6 +570,8 @@ void MVM_frame_invoke(MVMThreadContext *tc, MVMStaticFrame *static_frame,
             frame = allocate_frame(tc, static_frame, chosen_cand, 0);
             frame->spesh_correlation_id = 0;
         }
+        frame->code_ref = code_ref;
+        frame->outer = outer;
         if (chosen_cand->jitcode) {
             chosen_bytecode = chosen_cand->jitcode->bytecode;
             frame->jit_entry_label = chosen_cand->jitcode->labels[0];
@@ -593,6 +595,8 @@ void MVM_frame_invoke(MVMThreadContext *tc, MVMStaticFrame *static_frame,
             frame->effective_spesh_slots = NULL;
             frame->spesh_correlation_id = 0;
         }
+        frame->code_ref = code_ref;
+        frame->outer = outer;
         chosen_bytecode = static_frame->body.bytecode;
 
         /* If we should be spesh logging, set the correlation ID. */
@@ -616,12 +620,6 @@ void MVM_frame_invoke(MVMThreadContext *tc, MVMStaticFrame *static_frame,
         }
     }
 
-    /* Store the code ref (NULL at the top-level). */
-    frame->code_ref = code_ref;
-
-    /* Outer. */
-    frame->outer = outer;
-
     /* Initialize argument processing. */
     MVM_args_proc_init(tc, &frame->params, callsite, args);
 
@@ -719,6 +717,8 @@ void MVM_frame_dispatch(MVMThreadContext *tc, MVMCode *code, MVMArgs args, MVMin
             frame = allocate_frame(tc, static_frame, chosen_cand, 0);
             frame->spesh_correlation_id = 0;
         }
+        frame->code_ref = (MVMObject *)code;
+        frame->outer = outer;
         if (chosen_cand->jitcode) {
             chosen_bytecode = chosen_cand->jitcode->bytecode;
             frame->jit_entry_label = chosen_cand->jitcode->labels[0];
@@ -742,6 +742,8 @@ void MVM_frame_dispatch(MVMThreadContext *tc, MVMCode *code, MVMArgs args, MVMin
             frame->effective_spesh_slots = NULL;
             frame->spesh_correlation_id = 0;
         }
+        frame->code_ref = (MVMObject *)code;
+        frame->outer = outer;
         chosen_bytecode = static_frame->body.bytecode;
 
         /* If we should be spesh logging, set the correlation ID. */
@@ -766,12 +768,6 @@ void MVM_frame_dispatch(MVMThreadContext *tc, MVMCode *code, MVMArgs args, MVMin
         }
     }
 
-    /* Store the code ref (NULL at the top-level). */
-    frame->code_ref = (MVMObject *)code;
-
-    /* Outer. */
-    frame->outer = outer;
-
     /* Initialize argument processing. */
     MVM_args_proc_setup(tc, &(frame->params), args);