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Diffstat (limited to 'kernel/module.c')
-rw-r--r--kernel/module.c59
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);
generated by cgit v1.2.3 (git 2.39.0) at 2025-02-02 20:34:36 +0300