On Mon, 07 Oct 2019 10:25:45 +0200
Peter Zijlstra <pet...@infradead.org> wrote:
> Nothing ensures the module exists while we're iterating
> mod->jump_entries in __jump_label_mod_text_reserved(), take a module
> reference to ensure the module sticks around.
>
> Signed-off-by: Peter Zijlstra (Intel) <pet...@infradead.org>
Reviewed-by: Steven Rostedt (VMware) <rost...@goodmis.org>
-- Steve
> ---
> kernel/jump_label.c | 10 ++++++++--
> 1 file changed, 8 insertions(+), 2 deletions(-)
>
> --- a/kernel/jump_label.c
> +++ b/kernel/jump_label.c
> @@ -539,19 +539,25 @@ static void static_key_set_mod(struct st
> static int __jump_label_mod_text_reserved(void *start, void *end)
> {
> struct module *mod;
> + int ret;
>
> preempt_disable();
> mod = __module_text_address((unsigned long)start);
> WARN_ON_ONCE(__module_text_address((unsigned long)end) != mod);
> + if (!try_module_get(mod))
> + mod = NULL;
> preempt_enable();
>
> if (!mod)
> return 0;
>
> -
> - return __jump_label_text_reserved(mod->jump_entries,
> + ret = __jump_label_text_reserved(mod->jump_entries,
> mod->jump_entries + mod->num_jump_entries,
> start, end);
> +
> + module_put(mod);
> +
> + return ret;
> }
>
> static void __jump_label_mod_update(struct static_key *key)
>
