按源保护 PythonPlugin inittab 初始化边界

build-linuxcnc-wasm-standalone-probe.sh

@@ -7,7 +7,7 @@ cd "$(dirname "$0")"
 # rs274/tooldata sources directly or link wasm-safe shims whose source basis is
 # checked against LinuxCNC source comments before building.
 usage() {
-    echo "usage: $0 --mode tooldata-link|tooldata-common-link|interp-base-link|python-plugin-link|rs274ngc-pre-object" >&2
+    echo "usage: $0 --mode tooldata-link|tooldata-common-link|interp-base-link|python-plugin-link|python-plugin-inittab-link|rs274ngc-pre-object" >&2
 }
 
 mode=
@@ -33,7 +33,7 @@ while [[ "$#" -gt 0 ]]; do
     esac
 done
 case "$mode" in
-    tooldata-link|tooldata-common-link|interp-base-link|python-plugin-link|rs274ngc-pre-object)
+    tooldata-link|tooldata-common-link|interp-base-link|python-plugin-link|python-plugin-inittab-link|rs274ngc-pre-object)
         ;;
     "")
         usage
@@ -114,14 +114,21 @@ case "$mode" in
         )
         target_name=interp_base_probe
         ;;
-    python-plugin-link)
+    python-plugin-link|python-plugin-inittab-link)
         python_plugin_shim=$(./list-linuxcnc-wasm-safe-shims.sh python_plugin.cc)
-        grep -F 'LinuxCNC source basis: src/emc/pythonplugin/python_plugin.cc and' core/wasm_shims/pythonplugin/python_plugin_probe_main.cc >/dev/null
+        if [[ "$mode" == "python-plugin-link" ]]; then
+            probe_source=core/wasm_shims/pythonplugin/python_plugin_probe_main.cc
+            target_name=python_plugin_probe
+            grep -F 'LinuxCNC source basis: src/emc/pythonplugin/python_plugin.cc and' "$probe_source" >/dev/null
+        else
+            probe_source=core/wasm_shims/pythonplugin/python_plugin_inittab_probe_main.cc
+            target_name=python_plugin_inittab_probe
+            grep -F 'LinuxCNC source basis: src/emc/pythonplugin/python_plugin.cc' "$probe_source" >/dev/null
+        fi
         sources+=(
             "$python_plugin_shim"
-            core/wasm_shims/pythonplugin/python_plugin_probe_main.cc
+            "$probe_source"
         )
-        target_name=python_plugin_probe
         ;;
     rs274ngc-pre-object)
         rs274ngc_pre_source=$(LINUXCNC_ROOT="$linuxcnc_root" ./list-linuxcnc-source-files.sh src/emc/rs274ngc/rs274ngc_pre.cc)

check-linuxcnc-wasm-shims-source-map.sh

@@ -93,11 +93,15 @@ grep -F 'return vsnprintf(buffer, size, fmt, args);' \
 grep -F 'class PythonPlugin' "$linuxcnc_root/src/emc/pythonplugin/python_plugin.hh" >/dev/null
 grep -F 'PLUGIN_PYTHON_NOT_INITIALIZED = -12,' "$linuxcnc_root/src/emc/pythonplugin/python_plugin.hh" >/dev/null
 grep -F 'PLUGIN_BAD_PATH = -5,' "$linuxcnc_root/src/emc/pythonplugin/python_plugin.hh" >/dev/null
+grep -F 'PLUGIN_INITTAB_FAILED = -7 ,' "$linuxcnc_root/src/emc/pythonplugin/python_plugin.hh" >/dev/null
 grep -F 'PLUGIN_EXCEPTION_DURING_PATH_PREPEND = -9,' "$linuxcnc_root/src/emc/pythonplugin/python_plugin.hh" >/dev/null
 grep -F 'PLUGIN_EXCEPTION_DURING_PATH_APPEND = -10,' "$linuxcnc_root/src/emc/pythonplugin/python_plugin.hh" >/dev/null
 grep -F 'PLUGIN_NO_CALLABLE = 1,' "$linuxcnc_root/src/emc/pythonplugin/python_plugin.hh" >/dev/null
 grep -F 'PLUGIN_EXCEPTION = 2' "$linuxcnc_root/src/emc/pythonplugin/python_plugin.hh" >/dev/null
 grep -F 'PythonPlugin::instantiate' "$linuxcnc_root/src/emc/pythonplugin/python_plugin.cc" >/dev/null
+grep -F 'for (int i = 0; inittab[i].name != NULL; i++) {' "$linuxcnc_root/src/emc/pythonplugin/python_plugin.cc" >/dev/null
+grep -F 'if (module == NULL) {' "$linuxcnc_root/src/emc/pythonplugin/python_plugin.cc" >/dev/null
+grep -F 'status = PLUGIN_INITTAB_FAILED;' "$linuxcnc_root/src/emc/pythonplugin/python_plugin.cc" >/dev/null
 grep -F 'if (status < PLUGIN_OK)' "$linuxcnc_root/src/emc/pythonplugin/python_plugin.cc" >/dev/null
 grep -F 'if (auto inistring = inifile.findString("TOPLEVEL", section)) {' \
     "$linuxcnc_root/src/emc/pythonplugin/python_plugin.cc" >/dev/null
@@ -327,6 +331,7 @@ for needle in [
 
 python_plugin_shim = Path("core/wasm_shims/pythonplugin/python_plugin.cc").read_text(encoding="utf-8")
 python_plugin_probe = Path("core/wasm_shims/pythonplugin/python_plugin_probe_main.cc").read_text(encoding="utf-8")
+python_plugin_inittab_probe = Path("core/wasm_shims/pythonplugin/python_plugin_inittab_probe_main.cc").read_text(encoding="utf-8")
 python_c_api_shim = Path("core/wasm_shims/python_c_api_shim.cc").read_text(encoding="utf-8")
 for forbidden in [
     "bp::exec(",
@@ -340,6 +345,8 @@ for needle in [
     'find_ini_value(iniFilename, section, "TOPLEVEL", toplevel)',
     "realpath(toplevel.c_str(), resolved_path) == nullptr",
     "status = PLUGIN_BAD_PATH;",
+    "status = PLUGIN_INITTAB_FAILED;",
+    "failed to initialize built-in module",
     'check_python_path_entries(iniFilename,',
     "PLUGIN_EXCEPTION_DURING_PATH_PREPEND",
     "PLUGIN_EXCEPTION_DURING_PATH_APPEND",
@@ -351,6 +358,16 @@ for needle in [
 ]:
     if needle not in python_plugin_shim:
         raise SystemExit(f"PythonPlugin wasm shim missing disabled-python boundary: {needle}")
+for needle in [
+    "PythonPlugin::PythonPlugin(struct _inittab*) reports PLUGIN_INITTAB_FAILED",
+    "PythonPlugin *plugin = PythonPlugin::instantiate(bad_modules);",
+    "plugin != nullptr",
+    "python_plugin->plugin_status() != PLUGIN_INITTAB_FAILED",
+    "python_plugin->usable()",
+    'python_plugin->last_errmsg() != "failed to initialize built-in module"',
+]:
+    if needle not in python_plugin_inittab_probe:
+        raise SystemExit(f"PythonPlugin inittab probe missing first-caller status assertion: {needle}")
 for needle in [
     "PLUGIN_NO_SECTION",
     "PLUGIN_BAD_INIFILE",
@@ -437,6 +454,7 @@ for phrase in [
     "must not execute `bp::exec`, `bp::exec_file`, or",
     "inactive-DB return values",
     "negative-status short-circuit behavior",
+    "first-caller `_inittab` `PLUGIN_INITTAB_FAILED` edge",
     "preserve the `TOPLEVEL` missing-path `PLUGIN_BAD_PATH` edge",
     "preserve `PATH_PREPEND` and `PATH_APPEND` tilde-expansion failure statuses",
     "LinuxCNC `rcs_print_error` split entry points",

core/wasm_shims/pythonplugin/python_plugin.cc

@@ -113,10 +113,27 @@ int check_python_path_entries(const char *iniFilename,
 
 } // namespace
 
-PythonPlugin *PythonPlugin::instantiate(struct _inittab *) {
+PythonPlugin *PythonPlugin::instantiate(struct _inittab *inittab) {
     static PythonPlugin plugin;
-    python_plugin = &plugin;
+    if (!python_plugin) {
-    python_plugin->status = PLUGIN_OK;
+        python_plugin = &plugin;
+        python_plugin->status = PLUGIN_OK;
+        if (inittab) {
+            for (int i = 0; inittab[i].name != nullptr; ++i) {
+                // LinuxCNC source basis: python_plugin.cc reports
+                // PLUGIN_INITTAB_FAILED when a built-in module from the
+                // _inittab cannot be initialized.
+                if (!inittab[i].initfunc || inittab[i].initfunc() == nullptr) {
+                    python_plugin->error_msg = "failed to initialize built-in module";
+                    python_plugin->status = PLUGIN_INITTAB_FAILED;
+                    break;
+                }
+            }
+        }
+    }
+    if (!python_plugin->usable()) {
+        return nullptr;
+    }
     return python_plugin;
 }
 

core/wasm_shims/pythonplugin/python_plugin_inittab_probe_main.cc

@@ -0,0 +1,39 @@
+#include "pythonplugin/python_plugin.hh"
+
+namespace {
+
+PyObject *init_bad_module() {
+    return nullptr;
+}
+
+} // namespace
+
+// LinuxCNC source basis: src/emc/pythonplugin/python_plugin.cc
+// PythonPlugin::PythonPlugin(struct _inittab*) reports PLUGIN_INITTAB_FAILED
+// when a built-in Python module from the first caller's inittab cannot be
+// initialized; instantiate() then returns nullptr for the unusable plugin.
+int main() {
+    _inittab bad_modules[] = {
+        {"cnc_sim_bad_module", init_bad_module},
+        {nullptr, nullptr},
+    };
+
+    PythonPlugin *plugin = PythonPlugin::instantiate(bad_modules);
+    if (plugin != nullptr) {
+        return 1;
+    }
+    if (python_plugin == nullptr) {
+        return 2;
+    }
+    if (python_plugin->plugin_status() != PLUGIN_INITTAB_FAILED) {
+        return 3;
+    }
+    if (python_plugin->usable()) {
+        return 4;
+    }
+    if (python_plugin->last_errmsg() != "failed to initialize built-in module") {
+        return 5;
+    }
+
+    return 0;
+}

docs/linuxcnc-wasm-shims-source-map.md

@@ -61,8 +61,10 @@ only; it must not add CNC behavior and must not expand the temporary smoke parse
   `python_plugin.cc` link expectations; it must not call into CPython runtime.
 - `core/wasm_shims/pythonplugin/python_plugin.cc` must preserve LinuxCNC
   `PythonPlugin` status edges for `PLUGIN_NO_SECTION`, `PLUGIN_BAD_INIFILE`,
-  `PLUGIN_BAD_PATH`, `PLUGIN_PYTHON_NOT_INITIALIZED`, `PLUGIN_NO_CALLABLE`,
+  `PLUGIN_BAD_PATH`, `PLUGIN_INITTAB_FAILED`,
-  and `PLUGIN_EXCEPTION` while keeping Python execution disabled.
+  `PLUGIN_PYTHON_NOT_INITIALIZED`, `PLUGIN_NO_CALLABLE`, and
+  `PLUGIN_EXCEPTION` while keeping Python execution disabled.
+- The PythonPlugin shim must preserve the first-caller `_inittab` `PLUGIN_INITTAB_FAILED` edge from `src/emc/pythonplugin/python_plugin.cc` when a built-in module init function fails, while keeping browser-safe probes detached from real Python module execution.
 - The PythonPlugin shim must preserve the `TOPLEVEL` missing-path `PLUGIN_BAD_PATH` edge from `src/emc/pythonplugin/python_plugin.cc` before reporting the browser-safe disabled Python runtime status.
 - The PythonPlugin shim must preserve `PATH_PREPEND` and `PATH_APPEND` tilde-expansion failure statuses from `src/emc/pythonplugin/python_plugin.cc` and `src/emc/ini/inifile.cc` without executing Python path mutation in browser-safe probes.
 - The PythonPlugin shim must not execute `bp::exec`, `bp::exec_file`, or real

test-linuxcnc-wasm-python-plugin-link.sh

@@ -6,7 +6,9 @@ cd "$(dirname "$0")"
 # LinuxCNC source basis: src/emc/pythonplugin/python_plugin.cc and
 # python_plugin.hh define the PythonPlugin API covered by this wrapper.
 probe=$(./build-linuxcnc-wasm-standalone-probe.sh --mode python-plugin-link)
+inittab_probe=$(./build-linuxcnc-wasm-standalone-probe.sh --mode python-plugin-inittab-link)
 
 "$probe"
+"$inittab_probe"
 
 echo "linuxcnc wasm python_plugin link probe passed"

test-native.sh

@@ -80,6 +80,7 @@ grep -F 'LinuxCNC source basis: this probe derives required Python C API exports
 grep -F 'LinuxCNC source basis: this probe compares wasm-safe tooldata runtime stubs' test-linuxcnc-wasm-tooldata-runtime-symbols.sh >/dev/null
 grep -F 'LinuxCNC source basis: the standalone probe links src/emc/rs274ngc/interp_base.cc' test-linuxcnc-wasm-interp-base-link.sh >/dev/null
 grep -F 'LinuxCNC source basis: src/emc/pythonplugin/python_plugin.cc and' test-linuxcnc-wasm-python-plugin-link.sh >/dev/null
+grep -F 'python-plugin-inittab-link' test-linuxcnc-wasm-python-plugin-link.sh >/dev/null
 grep -F 'LinuxCNC source basis: src/emc/rs274ngc/rs274ngc_pre.cc is compiled directly' test-linuxcnc-wasm-rs274ngc-pre-object.sh >/dev/null
 grep -F 'LinuxCNC source basis: src/emc/rs274ngc/rs274ngc_pre.cc provides the Interp' test-linuxcnc-wasm-rs274ngc-pre-link.sh >/dev/null
 grep -F 'LinuxCNC source basis: src/emc/rs274ngc/rs274ngc_pre.cc provides read()' test-linuxcnc-wasm-runtime-link.sh >/dev/null