1 files changed, 44 insertions, 15 deletions

diff --git a/kernel/module.c b/kernel/module.c
index dd2a54155b54..f47cce910f25 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;
                 }