2 files changed, 18 insertions, 3 deletions
diff --git a/src/runtime/plugin.go b/src/runtime/plugin.go
index 7907936e14..845bf76e92 100644
--- a/src/runtime/plugin.go
+++ b/src/runtime/plugin.go
@@ -7,7 +7,7 @@ package runtime
 import "unsafe"
 
 //go:linkname plugin_lastmoduleinit plugin.lastmoduleinit
-func plugin_lastmoduleinit() (path string, syms map[string]interface{}) {
+func plugin_lastmoduleinit() (path string, syms map[string]interface{}, mismatchpkg string) {
 	md := firstmoduledata.next
 	if md == nil {
 		throw("runtime: no plugin module data")
@@ -41,6 +41,11 @@ func plugin_lastmoduleinit() (path string, syms map[string]interface{}) {
 			throw("plugin: new module data overlaps with previous moduledata")
 		}
 	}
+	for _, pkghash := range md.pkghashes {
+		if pkghash.linktimehash != *pkghash.runtimehash {
+			return "", nil, pkghash.modulename
+		}
+	}
 
 	// Initialize the freshly loaded module.
 	modulesinit()
@@ -74,7 +79,7 @@ func plugin_lastmoduleinit() (path string, syms map[string]interface{}) {
 		}
 		syms[name] = val
 	}
-	return md.pluginpath, syms
+	return md.pluginpath, syms, ""
 }
 
 // inRange reports whether v0 or v1 are in the range [r0, r1].
diff --git a/src/runtime/symtab.go b/src/runtime/symtab.go
index bba3ccfc20..686af08ef0 100644
--- a/src/runtime/symtab.go
+++ b/src/runtime/symtab.go
@@ -202,7 +202,9 @@ type moduledata struct {
 
 	ptab []ptabEntry
 
-	pluginpath   string
+	pluginpath string
+	pkghashes  []modulehash
+
 	modulename   string
 	modulehashes []modulehash
 
@@ -213,10 +215,18 @@ type moduledata struct {
 	next *moduledata
 }
 
+// A modulehash is used to compare the ABI of a new module or a
+// package in a new module with the loaded program.
+//
 // For each shared library a module links against, the linker creates an entry in the
 // moduledata.modulehashes slice containing the name of the module, the abi hash seen
 // at link time and a pointer to the runtime abi hash. These are checked in
 // moduledataverify1 below.
+//
+// For each loaded plugin, the the pkghashes slice has a modulehash of the
+// newly loaded package that can be used to check the plugin's version of
+// a package against any previously loaded version of the package.
+// This is done in plugin.lastmoduleinit.
 type modulehash struct {
 	modulename   string
 	linktimehash string