[PATCH bpf-next 11/15] bpf: Add bpf_sys_close() helper.
From: Alexei Starovoitov <hidden>
Date: 2021-04-17 03:33:37
Also in:
bpf
Subsystem:
bpf [core], bpf [general] (safe dynamic programs and tools), the rest · Maintainers:
Alexei Starovoitov, Daniel Borkmann, Andrii Nakryiko, Eduard Zingerman, Kumar Kartikeya Dwivedi, Linus Torvalds
From: Alexei Starovoitov <ast@kernel.org> Add bpf_sys_close() helper to be used by the syscall/loader program to close intermediate FDs and other cleanup. Signed-off-by: Alexei Starovoitov <ast@kernel.org> --- include/uapi/linux/bpf.h | 7 +++++++ kernel/bpf/syscall.c | 14 ++++++++++++++ tools/include/uapi/linux/bpf.h | 7 +++++++ 3 files changed, 28 insertions(+)
diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h
index 47c4b21a51b6..2251e7894799 100644
--- a/include/uapi/linux/bpf.h
+++ b/include/uapi/linux/bpf.h@@ -4728,6 +4728,12 @@ union bpf_attr { * If btf_fd is zero look for the name in vmlinux BTF and kernel module BTFs. * Return * Return btf_id and store module's BTF FD into attach_btf_obj_fd. + * + * long bpf_sys_close(u32 fd) + * Description + * Execute close syscall for given FD. + * Return + * A syscall result. */ #define __BPF_FUNC_MAPPER(FN) \ FN(unspec), \
@@ -4897,6 +4903,7 @@ union bpf_attr { FN(for_each_map_elem), \ FN(sys_bpf), \ FN(btf_find_by_name_kind), \ + FN(sys_close), \ /* */ /* integer value in 'imm' field of BPF_CALL instruction selects which helper
diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
index 6d4d9925c0ec..822b00908c58 100644
--- a/kernel/bpf/syscall.c
+++ b/kernel/bpf/syscall.c@@ -4557,6 +4557,18 @@ const struct bpf_func_proto bpf_sys_bpf_proto = { .arg3_type = ARG_CONST_SIZE, }; +BPF_CALL_1(bpf_sys_close, u32, fd) +{ + return close_fd(fd); +} + +const struct bpf_func_proto bpf_sys_close_proto = { + .func = bpf_sys_close, + .gpl_only = false, + .ret_type = RET_INTEGER, + .arg1_type = ARG_ANYTHING, +}; + static const struct bpf_func_proto * syscall_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) {
@@ -4565,6 +4577,8 @@ syscall_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) return &bpf_sys_bpf_proto; case BPF_FUNC_btf_find_by_name_kind: return &bpf_btf_find_by_name_kind_proto; + case BPF_FUNC_sys_close: + return &bpf_sys_close_proto; default: return bpf_base_func_proto(func_id); }
diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h
index 47c4b21a51b6..2251e7894799 100644
--- a/tools/include/uapi/linux/bpf.h
+++ b/tools/include/uapi/linux/bpf.h@@ -4728,6 +4728,12 @@ union bpf_attr { * If btf_fd is zero look for the name in vmlinux BTF and kernel module BTFs. * Return * Return btf_id and store module's BTF FD into attach_btf_obj_fd. + * + * long bpf_sys_close(u32 fd) + * Description + * Execute close syscall for given FD. + * Return + * A syscall result. */ #define __BPF_FUNC_MAPPER(FN) \ FN(unspec), \
@@ -4897,6 +4903,7 @@ union bpf_attr { FN(for_each_map_elem), \ FN(sys_bpf), \ FN(btf_find_by_name_kind), \ + FN(sys_close), \ /* */ /* integer value in 'imm' field of BPF_CALL instruction selects which helper
--
2.30.2