From ac9f06050a3580cf4076a57a470cd71f12a81171 Mon Sep 17 00:00:00 2001 From: Kumar Kartikeya Dwivedi Date: Fri, 18 Nov 2022 07:26:04 +0530 Subject: bpf: Introduce bpf_obj_drop Introduce bpf_obj_drop, which is the kfunc used to free allocated objects (allocated using bpf_obj_new). Pairing with bpf_obj_new, it implicitly destructs the fields part of object automatically without user intervention. Just like the previous patch, btf_struct_meta that is needed to free up the special fields is passed as a hidden argument to the kfunc. For the user, a convenience macro hides over the kernel side kfunc which is named bpf_obj_drop_impl. Continuing the previous example: void prog(void) { struct foo *f; f = bpf_obj_new(typeof(*f)); if (!f) return; bpf_obj_drop(f); } Signed-off-by: Kumar Kartikeya Dwivedi Link: https://lore.kernel.org/r/20221118015614.2013203-15-memxor@gmail.com Signed-off-by: Alexei Starovoitov --- tools/testing/selftests/bpf/bpf_experimental.h | 13 +++++++++++++ 1 file changed, 13 insertions(+) (limited to 'tools') diff --git a/tools/testing/selftests/bpf/bpf_experimental.h b/tools/testing/selftests/bpf/bpf_experimental.h index aeb6a7fcb7c4..8473395a11af 100644 --- a/tools/testing/selftests/bpf/bpf_experimental.h +++ b/tools/testing/selftests/bpf/bpf_experimental.h @@ -22,4 +22,17 @@ extern void *bpf_obj_new_impl(__u64 local_type_id, void *meta) __ksym; /* Convenience macro to wrap over bpf_obj_new_impl */ #define bpf_obj_new(type) ((type *)bpf_obj_new_impl(bpf_core_type_id_local(type), NULL)) +/* Description + * Free an allocated object. All fields of the object that require + * destruction will be destructed before the storage is freed. + * + * The 'meta' parameter is a hidden argument that is ignored. + * Returns + * Void. + */ +extern void bpf_obj_drop_impl(void *kptr, void *meta) __ksym; + +/* Convenience macro to wrap over bpf_obj_drop_impl */ +#define bpf_obj_drop(kptr) bpf_obj_drop_impl(kptr, NULL) + #endif -- cgit