1 files changed, 33 insertions, 26 deletions

diff --git a/kernel/module.c b/kernel/module.c
index a65dc787a27b..e5538d5f00ad 100644
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -474,9 +474,10 @@ static void module_unload_init(struct module *mod)
 
         INIT_LIST_HEAD(&mod->modules_which_use_me);
         for_each_possible_cpu(cpu)
-                local_set(__module_ref_addr(mod, cpu), 0);
+                per_cpu_ptr(mod->refptr, cpu)->count = 0;
+
         /* Hold reference count during initialization. */
-        local_set(__module_ref_addr(mod, raw_smp_processor_id()), 1);
+        __this_cpu_write(mod->refptr->count, 1);
         /* Backwards compatibility macros put refcount during init. */
         mod->waiter = current;
 }
@@ -619,7 +620,7 @@ unsigned int module_refcount(struct module *mod)
         int cpu;
 
         for_each_possible_cpu(cpu)
-                total += local_read(__module_ref_addr(mod, cpu));
+                total += per_cpu_ptr(mod->refptr, cpu)->count;
         return total;
 }
 EXPORT_SYMBOL(module_refcount);
@@ -796,14 +797,15 @@ static struct module_attribute refcnt = {
 void module_put(struct module *module)
 {
         if (module) {
-                unsigned int cpu = get_cpu();
-                local_dec(__module_ref_addr(module, cpu));
+                preempt_disable();
+                __this_cpu_dec(module->refptr->count);
+
                 trace_module_put(module, _RET_IP_,
-                                 local_read(__module_ref_addr(module, cpu)));
+                                 __this_cpu_read(module->refptr->count));
                 /* Maybe they're waiting for us to drop reference? */
                 if (unlikely(!module_is_live(module)))
                         wake_up_process(module->waiter);
-                put_cpu();
+                preempt_enable();
         }
 }
 EXPORT_SYMBOL(module_put);
@@ -1010,6 +1012,12 @@ static const struct kernel_symbol *resolve_symbol(Elf_Shdr *sechdrs,
  * J. Corbet <corbet@lwn.net>
  */
 #if defined(CONFIG_KALLSYMS) && defined(CONFIG_SYSFS)
+
+static inline bool sect_empty(const Elf_Shdr *sect)
+{
+        return !(sect->sh_flags & SHF_ALLOC) || sect->sh_size == 0;
+}
+
 struct module_sect_attr
 {
         struct module_attribute mattr;
@@ -1051,8 +1059,7 @@ static void add_sect_attrs(struct module *mod, unsigned int nsect,
 
         /* Count loaded sections and allocate structures */
         for (i = 0; i < nsect; i++)
-                if (sechdrs[i].sh_flags & SHF_ALLOC
-                    && sechdrs[i].sh_size)
+                if (!sect_empty(&sechdrs[i]))
                         nloaded++;
         size[0] = ALIGN(sizeof(*sect_attrs)
                         + nloaded * sizeof(sect_attrs->attrs[0]),
@@ -1070,9 +1077,7 @@ static void add_sect_attrs(struct module *mod, unsigned int nsect,
         sattr = &sect_attrs->attrs[0];
         gattr = &sect_attrs->grp.attrs[0];
         for (i = 0; i < nsect; i++) {
-                if (! (sechdrs[i].sh_flags & SHF_ALLOC))
-                        continue;
-                if (!sechdrs[i].sh_size)
+                if (sect_empty(&sechdrs[i]))
                         continue;
                 sattr->address = sechdrs[i].sh_addr;
                 sattr->name = kstrdup(secstrings + sechdrs[i].sh_name,
@@ -1156,7 +1161,7 @@ static void add_notes_attrs(struct module *mod, unsigned int nsect,
         /* Count notes sections and allocate structures.  */
         notes = 0;
         for (i = 0; i < nsect; i++)
-                if ((sechdrs[i].sh_flags & SHF_ALLOC) &&
+                if (!sect_empty(&sechdrs[i]) &&
                     (sechdrs[i].sh_type == SHT_NOTE))
                         ++notes;
 
@@ -1172,7 +1177,7 @@ static void add_notes_attrs(struct module *mod, unsigned int nsect,
         notes_attrs->notes = notes;
         nattr = &notes_attrs->attrs[0];
         for (loaded = i = 0; i < nsect; ++i) {
-                if (!(sechdrs[i].sh_flags & SHF_ALLOC))
+                if (sect_empty(&sechdrs[i]))
                         continue;
                 if (sechdrs[i].sh_type == SHT_NOTE) {
                         nattr->attr.name = mod->sect_attrs->attrs[loaded].name;
@@ -1394,9 +1399,9 @@ static void free_module(struct module *mod)
         kfree(mod->args);
         if (mod->percpu)
                 percpu_modfree(mod->percpu);
-#if defined(CONFIG_MODULE_UNLOAD) && defined(CONFIG_SMP)
+#if defined(CONFIG_MODULE_UNLOAD)
         if (mod->refptr)
-                percpu_modfree(mod->refptr);
+                free_percpu(mod->refptr);
 #endif
         /* Free lock-classes: */
         lockdep_free_key_range(mod->module_core, mod->core_size);
@@ -1910,9 +1915,7 @@ static void kmemleak_load_module(struct module *mod, Elf_Ehdr *hdr,
         unsigned int i;
 
         /* only scan the sections containing data */
-        kmemleak_scan_area(mod->module_core, (unsigned long)mod -
-                           (unsigned long)mod->module_core,
-                           sizeof(struct module), GFP_KERNEL);
+        kmemleak_scan_area(mod, sizeof(struct module), GFP_KERNEL);
 
         for (i = 1; i < hdr->e_shnum; i++) {
                 if (!(sechdrs[i].sh_flags & SHF_ALLOC))
@@ -1921,8 +1924,7 @@ static void kmemleak_load_module(struct module *mod, Elf_Ehdr *hdr,
                     && strncmp(secstrings + sechdrs[i].sh_name, ".bss", 4) != 0)
                         continue;
 
-                kmemleak_scan_area(mod->module_core, sechdrs[i].sh_addr -
-                                   (unsigned long)mod->module_core,
+                kmemleak_scan_area((void *)sechdrs[i].sh_addr,
                                    sechdrs[i].sh_size, GFP_KERNEL);
         }
 }
@@ -2162,9 +2164,8 @@ static noinline struct module *load_module(void __user *umod,
         mod = (void *)sechdrs[modindex].sh_addr;
         kmemleak_load_module(mod, hdr, sechdrs, secstrings);
 
-#if defined(CONFIG_MODULE_UNLOAD) && defined(CONFIG_SMP)
-        mod->refptr = percpu_modalloc(sizeof(local_t), __alignof__(local_t),
-                                      mod->name);
+#if defined(CONFIG_MODULE_UNLOAD)
+        mod->refptr = alloc_percpu(struct module_ref);
         if (!mod->refptr) {
                 err = -ENOMEM;
                 goto free_init;
@@ -2250,6 +2251,12 @@ static noinline struct module *load_module(void __user *umod,
                                          "_ftrace_events",
                                          sizeof(*mod->trace_events),
                                          &mod->num_trace_events);
+        /*
+         * This section contains pointers to allocated objects in the trace
+         * code and not scanning it leads to false positives.
+         */
+        kmemleak_scan_area(mod->trace_events, sizeof(*mod->trace_events) *
+                           mod->num_trace_events, GFP_KERNEL);
 #endif
 #ifdef CONFIG_FTRACE_MCOUNT_RECORD
         /* sechdrs[0].sh_size is always zero */
@@ -2390,8 +2397,8 @@ static noinline struct module *load_module(void __user *umod,
         kobject_put(&mod->mkobj.kobj);
  free_unload:
         module_unload_free(mod);
-#if defined(CONFIG_MODULE_UNLOAD) && defined(CONFIG_SMP)
-        percpu_modfree(mod->refptr);
+#if defined(CONFIG_MODULE_UNLOAD)
+        free_percpu(mod->refptr);
  free_init:
 #endif
         module_free(mod, mod->module_init);