1 files changed, 22 insertions, 2 deletions

diff --git a/kernel/module.c b/kernel/module.c
index 5c7eb0695b3..d8b5605132a 100644
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -70,6 +70,9 @@ static DECLARE_WAIT_QUEUE_HEAD(module_wq);
 
 static BLOCKING_NOTIFIER_HEAD(module_notify_list);
 
+/* Bounds of module allocation, for speeding __module_text_address */
+static unsigned long module_addr_min = -1UL, module_addr_max = 0;
+
 int register_module_notifier(struct notifier_block * nb)
 {
         return blocking_notifier_chain_register(&module_notify_list, nb);
@@ -1779,6 +1782,20 @@ static inline void add_kallsyms(struct module *mod,
 }
 #endif /* CONFIG_KALLSYMS */
 
+static void *module_alloc_update_bounds(unsigned long size)
+{
+        void *ret = module_alloc(size);
+
+        if (ret) {
+                /* Update module bounds. */
+                if ((unsigned long)ret < module_addr_min)
+                        module_addr_min = (unsigned long)ret;
+                if ((unsigned long)ret + size > module_addr_max)
+                        module_addr_max = (unsigned long)ret + size;
+        }
+        return ret;
+}
+
 /* Allocate and load the module: note that size of section 0 is always
    zero, and we rely on this for optional sections. */
 static struct module *load_module(void __user *umod,
@@ -1980,7 +1997,7 @@ static struct module *load_module(void __user *umod,
         layout_sections(mod, hdr, sechdrs, secstrings);
 
         /* Do the allocs. */
-        ptr = module_alloc(mod->core_size);
+        ptr = module_alloc_update_bounds(mod->core_size);
         if (!ptr) {
                 err = -ENOMEM;
                 goto free_percpu;
@@ -1988,7 +2005,7 @@ static struct module *load_module(void __user *umod,
         memset(ptr, 0, mod->core_size);
         mod->module_core = ptr;
 
-        ptr = module_alloc(mod->init_size);
+        ptr = module_alloc_update_bounds(mod->init_size);
         if (!ptr && mod->init_size) {
                 err = -ENOMEM;
                 goto free_core;
@@ -2645,6 +2662,9 @@ struct module *__module_text_address(unsigned long addr)
 {
         struct module *mod;
 
+        if (addr < module_addr_min || addr > module_addr_max)
+                return NULL;
+
         list_for_each_entry(mod, &modules, list)
                 if (within(addr, mod->module_init, mod->init_text_size)
                     || within(addr, mod->module_core, mod->core_text_size))