Commit 9492450f authored by Kumar Kartikeya Dwivedi's avatar Kumar Kartikeya Dwivedi Committed by Alexei Starovoitov
Browse files

bpf: Always raise reference in btf_get_module_btf 



Align it with helpers like bpf_find_btf_id, so all functions returning
BTF in out parameter follow the same rule of raising reference
consistently, regardless of module or vmlinux BTF.

Adjust existing callers to handle the change accordinly.

Signed-off-by: default avatarKumar Kartikeya Dwivedi <memxor@gmail.com>
Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20220317115957.3193097-10-memxor@gmail.com
parent edc3ec09

kernel/bpf/btf.c

+11 −10
Original line number Diff line number Diff line
@@ -6572,20 +6572,23 @@ struct module *btf_try_get_module(const struct btf *btf) 
	return res;

}



/* Returns struct btf corresponding to the struct module

 *

 * This function can return NULL or ERR_PTR. Note that caller must

 * release reference for struct btf iff btf_is_module is true.

/* Returns struct btf corresponding to the struct module.

 * This function can return NULL or ERR_PTR.

 */

static struct btf *btf_get_module_btf(const struct module *module)

{

	struct btf *btf = NULL;

#ifdef CONFIG_DEBUG_INFO_BTF_MODULES

	struct btf_module *btf_mod, *tmp;

#endif

	struct btf *btf = NULL;



	if (!module) {

		btf = bpf_get_btf_vmlinux();

		if (!IS_ERR(btf))

			btf_get(btf);

		return btf;

	}



	if (!module)

		return bpf_get_btf_vmlinux();

#ifdef CONFIG_DEBUG_INFO_BTF_MODULES

	mutex_lock(&btf_module_mutex);

	list_for_each_entry_safe(btf_mod, tmp, &btf_modules, list) {
@@ -6823,8 +6826,6 @@ int register_btf_kfunc_id_set(enum bpf_prog_type prog_type, 


	hook = bpf_prog_type_to_kfunc_hook(prog_type);

	ret = btf_populate_kfunc_set(btf, hook, kset);

	/* reference is only taken for module BTF */

	if (btf_is_module(btf))

	btf_put(btf);

	return ret;

}