From 9492450fd28736262dea9143ebb3afc2c131ace1 Mon Sep 17 00:00:00 2001 From: Kumar Kartikeya Dwivedi Date: Thu, 17 Mar 2022 17:29:51 +0530 Subject: [PATCH] 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: Kumar Kartikeya Dwivedi Signed-off-by: Alexei Starovoitov Link: https://lore.kernel.org/bpf/20220317115957.3193097-10-memxor@gmail.com --- kernel/bpf/btf.c | 21 +++++++++++---------- 1 file changed, 11 insertions(+), 10 deletions(-) diff --git a/kernel/bpf/btf.c b/kernel/bpf/btf.c index 17b9adcd88d3..6d9e711cb5d4 100644 --- a/kernel/bpf/btf.c +++ b/kernel/bpf/btf.c @@ -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) { @@ -6823,9 +6826,7 @@ 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); + btf_put(btf); return ret; } EXPORT_SYMBOL_GPL(register_btf_kfunc_id_set);