diff options
| author | Sebastian Andrzej Siewior <bigeasy@linutronix.de> | 2025-01-08 10:04:33 +0100 |
|---|---|---|
| committer | Petr Pavlu <petr.pavlu@suse.com> | 2025-03-10 11:54:44 +0100 |
| commit | f01369239293e4900af7be673e0fd26fe54f85e1 (patch) | |
| tree | 6a4fa6429e3fd77634017b56ccc94259898ef9b1 /kernel/module | |
| parent | 039de46874bb08fef027342c9c5077f2ea85ab42 (diff) | |
module: Use RCU in find_kallsyms_symbol().
The modules list and module::kallsyms can be accessed under RCU
assumption.
Use rcu_dereference() to reference the kallsyms pointer in
find_kallsyms_symbol(). Use a RCU section instead of preempt_disable in
callers of find_kallsyms_symbol(). Keep the preempt-disable in
module_address_lookup() due to __module_address().
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20250108090457.512198-5-bigeasy@linutronix.de
Signed-off-by: Petr Pavlu <petr.pavlu@suse.com>
Diffstat (limited to 'kernel/module')
| -rw-r--r-- | kernel/module/kallsyms.c | 7 |
1 files changed, 3 insertions, 4 deletions
diff --git a/kernel/module/kallsyms.c b/kernel/module/kallsyms.c index 45846ae4042d..3f59d0479557 100644 --- a/kernel/module/kallsyms.c +++ b/kernel/module/kallsyms.c @@ -257,7 +257,7 @@ static const char *find_kallsyms_symbol(struct module *mod, { unsigned int i, best = 0; unsigned long nextval, bestval; - struct mod_kallsyms *kallsyms = rcu_dereference_sched(mod->kallsyms); + struct mod_kallsyms *kallsyms = rcu_dereference(mod->kallsyms); struct module_memory *mod_mem; /* At worse, next value is at end of module */ @@ -329,6 +329,7 @@ int module_address_lookup(unsigned long addr, int ret = 0; struct module *mod; + guard(rcu)(); preempt_disable(); mod = __module_address(addr); if (mod) { @@ -356,7 +357,7 @@ int lookup_module_symbol_name(unsigned long addr, char *symname) { struct module *mod; - preempt_disable(); + guard(rcu)(); list_for_each_entry_rcu(mod, &modules, list) { if (mod->state == MODULE_STATE_UNFORMED) continue; @@ -368,12 +369,10 @@ int lookup_module_symbol_name(unsigned long addr, char *symname) goto out; strscpy(symname, sym, KSYM_NAME_LEN); - preempt_enable(); return 0; } } out: - preempt_enable(); return -ERANGE; } |