1 files changed, 44 insertions, 15 deletions

diff --git a/kernel/module.c b/kernel/module.c
index dd2a541..f47cce9 100644
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -757,8 +757,16 @@ sys_delete_module(const char __user *name_user, unsigned int flags)
 		return -EFAULT;
 	name[MODULE_NAME_LEN-1] = '\0';
 
-	if (mutex_lock_interruptible(&module_mutex) != 0)
-		return -EINTR;
+	/* Create stop_machine threads since free_module relies on
+	 * a non-failing stop_machine call. */
+	ret = stop_machine_create();
+	if (ret)
+		return ret;
+
+	if (mutex_lock_interruptible(&module_mutex) != 0) {
+		ret = -EINTR;
+		goto out_stop;
+	}
 
 	mod = find_module(name);
 	if (!mod) {
@@ -817,10 +825,12 @@ sys_delete_module(const char __user *name_user, unsigned int flags)
 
  out:
 	mutex_unlock(&module_mutex);
+out_stop:
+	stop_machine_destroy();
 	return ret;
 }
 
-static void print_unload_info(struct seq_file *m, struct module *mod)
+static inline void print_unload_info(struct seq_file *m, struct module *mod)
 {
 	struct module_use *use;
 	int printed_something = 0;
@@ -893,7 +903,7 @@ void module_put(struct module *module)
 EXPORT_SYMBOL(module_put);
 
 #else /* !CONFIG_MODULE_UNLOAD */
-static void print_unload_info(struct seq_file *m, struct module *mod)
+static inline void print_unload_info(struct seq_file *m, struct module *mod)
 {
 	/* We don't know the usage count, or what modules are using. */
 	seq_printf(m, " - -");
@@ -1578,11 +1588,21 @@ static int simplify_symbols(Elf_Shdr *sechdrs,
 	return ret;
 }
 
+/* Additional bytes needed by arch in front of individual sections */
+unsigned int __weak arch_mod_section_prepend(struct module *mod,
+					     unsigned int section)
+{
+	/* default implementation just returns zero */
+	return 0;
+}
+
 /* Update size with this section: return offset. */
-static long get_offset(unsigned int *size, Elf_Shdr *sechdr)
+static long get_offset(struct module *mod, unsigned int *size,
+		       Elf_Shdr *sechdr, unsigned int section)
 {
 	long ret;
 
+	*size += arch_mod_section_prepend(mod, section);
 	ret = ALIGN(*size, sechdr->sh_addralign ?: 1);
 	*size = ret + sechdr->sh_size;
 	return ret;
@@ -1622,7 +1642,7 @@ static void layout_sections(struct module *mod,
 			    || strncmp(secstrings + s->sh_name,
 				       ".init", 5) == 0)
 				continue;
-			s->sh_entsize = get_offset(&mod->core_size, s);
+			s->sh_entsize = get_offset(mod, &mod->core_size, s, i);
 			DEBUGP("\t%s\n", secstrings + s->sh_name);
 		}
 		if (m == 0)
@@ -1640,7 +1660,7 @@ static void layout_sections(struct module *mod,
 			    || strncmp(secstrings + s->sh_name,
 				       ".init", 5) != 0)
 				continue;
-			s->sh_entsize = (get_offset(&mod->init_size, s)
+			s->sh_entsize = (get_offset(mod, &mod->init_size, s, i)
 					 | INIT_OFFSET_MASK);
 			DEBUGP("\t%s\n", secstrings + s->sh_name);
 		}
@@ -1725,15 +1745,15 @@ static const struct kernel_symbol *lookup_symbol(const char *name,
 	return NULL;
 }
 
-static int is_exported(const char *name, const struct module *mod)
+static int is_exported(const char *name, unsigned long value,
+		       const struct module *mod)
 {
-	if (!mod && lookup_symbol(name, __start___ksymtab, __stop___ksymtab))
-		return 1;
+	const struct kernel_symbol *ks;
+	if (!mod)
+		ks = lookup_symbol(name, __start___ksymtab, __stop___ksymtab);
 	else
-		if (mod && lookup_symbol(name, mod->syms, mod->syms + mod->num_syms))
-			return 1;
-		else
-			return 0;
+		ks = lookup_symbol(name, mod->syms, mod->syms + mod->num_syms);
+	return ks != NULL && ks->value == value;
 }
 
 /* As per nm */
@@ -1865,6 +1885,13 @@ static noinline struct module *load_module(void __user *umod,
 	/* vmalloc barfs on "unusual" numbers.  Check here */
 	if (len > 64 * 1024 * 1024 || (hdr = vmalloc(len)) == NULL)
 		return ERR_PTR(-ENOMEM);
+
+	/* Create stop_machine threads since the error path relies on
+	 * a non-failing stop_machine call. */
+	err = stop_machine_create();
+	if (err)
+		goto free_hdr;
+
 	if (copy_from_user(hdr, umod, len) != 0) {
 		err = -EFAULT;
 		goto free_hdr;
@@ -2248,6 +2275,7 @@ static noinline struct module *load_module(void __user *umod,
 	/* Get rid of temporary copy */
 	vfree(hdr);
 
+	stop_machine_destroy();
 	/* Done! */
 	return mod;
 
@@ -2270,6 +2298,7 @@ static noinline struct module *load_module(void __user *umod,
 	kfree(args);
  free_hdr:
 	vfree(hdr);
+	stop_machine_destroy();
 	return ERR_PTR(err);
 
  truncated:
@@ -2504,7 +2533,7 @@ int module_get_kallsym(unsigned int symnum, unsigned long *value, char *type,
 			strlcpy(name, mod->strtab + mod->symtab[symnum].st_name,
 				KSYM_NAME_LEN);
 			strlcpy(module_name, mod->name, MODULE_NAME_LEN);
-			*exported = is_exported(name, mod);
+			*exported = is_exported(name, *value, mod);
 			preempt_enable();
 			return 0;
 		}