phase 5

spikes/wasm-phase0/FINDINGS.md

@@ -125,6 +125,15 @@ addresses read from core's exported data-symbol globals) → instantiate →
 patch deferred GOT entries → `__wasm_apply_data_relocs` → `__wasm_call_ctors`
 → call the entry export.
 
+- **Erratum (found in Phase 3): self-resolved `GOT.mem` values must add
+  `__memory_base`.** A PIC module's exported data symbols are i32 globals
+  holding offsets *relative to its `__memory_base`*, not absolute addresses —
+  the linker adds the base when patching deferred GOT entries (there is no
+  `__wasm_apply_global_relocs` export to do it). Copying the export verbatim
+  reads/writes core memory at low addresses and renders silently wrong values;
+  the Phase 3 fixture's `self-got`/`callback` markers exist to catch exactly
+  this. `GOT.mem` entries resolved from the *core's* exports are absolute
+  already (the core is non-PIC) and need no adjustment.
 - **GOT.func is resolved guest-side**: the core exports a helper returning
   `(intptr_t)&func` — taking the address forces a link-time elem entry and a
   wasm function pointer *is* its table index. No host-side funcref injection

spikes/wasm-phase0/loader.cpp

@@ -394,9 +394,11 @@ int main(int argc, char** argv)
 		CHECK(own, "GOT.mem.%s defined neither by core nor by unit", nm.c_str());
 		wasm_val_t v;
 		wasm_global_get(own, &v);
-		wasm_val_t nv = WASM_I32_VAL(v.of.i32);
+		// dylink ABI: a PIC module's exported data symbols are offsets relative
+		// to its __memory_base; the linker must add the base when resolving
+		wasm_val_t nv = WASM_I32_VAL(memory_base + v.of.i32);
 		wasm_global_set(got, &nv);
-		printf("self-resolved GOT.mem.%s = %d\n", nm.c_str(), v.of.i32);
+		printf("self-resolved GOT.mem.%s = %d (offset %d)\n", nm.c_str(), memory_base + v.of.i32, v.of.i32);
 	}
 
 	if(unit.func("__wasm_apply_data_relocs"))