---

yaml
---
r: 17007
b: refs/heads/master
c: eea8b54
h: refs/heads/master
i:
  17005: cc50c14
  17003: d882243
  16999: 98aa08f
  16991: 54619c1
v: v3

[refs]

@@ -1,2 +1,2 @@
 ---
-refs/heads/master: b368fae6abaa1736b8f26128c32947d47237b8e5
+refs/heads/master: eea8b54dc0dceb740da697a89c54d20dde340306

trunk/kernel/module.c

@@ -1204,6 +1204,39 @@ void *__symbol_get(const char *symbol)
 }
 EXPORT_SYMBOL_GPL(__symbol_get);
 
+/*
+ * Ensure that an exported symbol [global namespace] does not already exist
+ * in the Kernel or in some other modules exported symbol table.
+ */
+static int verify_export_symbols(struct module *mod)
+{
+	const char *name = NULL;
+	unsigned long i, ret = 0;
+	struct module *owner;
+	const unsigned long *crc;
+
+	for (i = 0; i < mod->num_syms; i++)
+	        if (__find_symbol(mod->syms[i].name, &owner, &crc, 1)) {
+			name = mod->syms[i].name;
+			ret = -ENOEXEC;
+			goto dup;
+		}
+
+	for (i = 0; i < mod->num_gpl_syms; i++)
+	        if (__find_symbol(mod->gpl_syms[i].name, &owner, &crc, 1)) {
+			name = mod->gpl_syms[i].name;
+			ret = -ENOEXEC;
+			goto dup;
+		}
+
+dup:
+	if (ret)
+		printk(KERN_ERR "%s: exports duplicate symbol %s (owned by %s)\n",
+			mod->name, name, module_name(owner));
+
+	return ret;
+}
+
 /* Change all symbols so that sh_value encodes the pointer directly. */
 static int simplify_symbols(Elf_Shdr *sechdrs,
 			    unsigned int symindex,
@@ -1772,6 +1805,12 @@ static struct module *load_module(void __user *umod,
 			goto cleanup;
 	}
 
+        /* Find duplicate symbols */
+	err = verify_export_symbols(mod);
+
+	if (err < 0)
+		goto cleanup;
+
   	/* Set up and sort exception table */
 	mod->num_exentries = sechdrs[exindex].sh_size / sizeof(*mod->extable);
 	mod->extable = extable = (void *)sechdrs[exindex].sh_addr;