module: Use RCU in __find_kallsyms_symbol_value().

module::kallsyms can be accessed under RCU assumption.

Use rcu_dereference() to access module::kallsyms.
Update callers.

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20250108090457.512198-8-bigeasy@linutronix.de
Signed-off-by: Petr Pavlu <petr.pavlu@suse.com>

diff --git a/kernel/module/kallsyms.c b/kernel/module/kallsyms.c
index 3cba9f933b24fc09de0f8dafb75dfbfc37c85320..e3c55bc879c110c61cdcce0641d616644b748440 100644 (file)
--- a/kernel/module/kallsyms.c
+++ b/kernel/module/kallsyms.c
@@ -407,7 +407,7 @@ int module_get_kallsym(unsigned int symnum, unsigned long *value, char *type,
 static unsigned long __find_kallsyms_symbol_value(struct module *mod, const char *name)
 {
        unsigned int i;
-       struct mod_kallsyms *kallsyms = rcu_dereference_sched(mod->kallsyms);
+       struct mod_kallsyms *kallsyms = rcu_dereference(mod->kallsyms);
 
        for (i = 0; i < kallsyms->num_symtab; i++) {
                const Elf_Sym *sym = &kallsyms->symtab[i];
@@ -447,24 +447,15 @@ static unsigned long __module_kallsyms_lookup_name(const char *name)
 /* Look for this name: can be of form module:name. */
 unsigned long module_kallsyms_lookup_name(const char *name)
 {
-       unsigned long ret;
-
        /* Don't lock: we're in enough trouble already. */
        guard(rcu)();
-       preempt_disable();
-       ret = __module_kallsyms_lookup_name(name);
-       preempt_enable();
-       return ret;
+       return __module_kallsyms_lookup_name(name);
 }
 
 unsigned long find_kallsyms_symbol_value(struct module *mod, const char *name)
 {
-       unsigned long ret;
-
-       preempt_disable();
-       ret = __find_kallsyms_symbol_value(mod, name);
-       preempt_enable();
-       return ret;
+       guard(rcu)();
+       return __find_kallsyms_symbol_value(mod, name);
 }
 
 int module_kallsyms_on_each_symbol(const char *modname,