[v4,bpf-next,4/7] libbpf: prog load: allow to use fd_array_cnt

Commit Message

Anton Protopopov Dec. 3, 2024, 1:50 p.m. UTC

Add new fd_array_cnt field to bpf_prog_load_opts
and pass it in bpf_attr, if set.

Signed-off-by: Anton Protopopov <[e-mail]>
---
 tools/lib/bpf/bpf.c | 3 ++-
 tools/lib/bpf/bpf.h | 5 ++++-
 2 files changed, 6 insertions(+), 2 deletions(-)

Comments

Andrii Nakryiko Dec. 3, 2024, 9:26 p.m. UTC | #1

On Tue, Dec 3, 2024 at 5:48 AM Anton Protopopov <[e-mail]> wrote:
>
> Add new fd_array_cnt field to bpf_prog_load_opts
> and pass it in bpf_attr, if set.
>
> Signed-off-by: Anton Protopopov <[e-mail]>
> ---
>  tools/lib/bpf/bpf.c | 3 ++-
>  tools/lib/bpf/bpf.h | 5 ++++-
>  2 files changed, 6 insertions(+), 2 deletions(-)
>

LGTM

Acked-by: Andrii Nakryiko <[e-mail]>


[...]

Patch

diff --git a/tools/lib/bpf/bpf.c b/tools/lib/bpf/bpf.c
index becdfa701c75..359f73ead613 100644
--- a/tools/lib/bpf/bpf.c
+++ b/tools/lib/bpf/bpf.c
@@ -238,7 +238,7 @@  int bpf_prog_load(enum bpf_prog_type prog_type,
 		  const struct bpf_insn *insns, size_t insn_cnt,
 		  struct bpf_prog_load_opts *opts)
 {
-	const size_t attr_sz = offsetofend(union bpf_attr, prog_token_fd);
+	const size_t attr_sz = offsetofend(union bpf_attr, fd_array_cnt);
 	void *finfo = NULL, *linfo = NULL;
 	const char *func_info, *line_info;
 	__u32 log_size, log_level, attach_prog_fd, attach_btf_obj_fd;
@@ -311,6 +311,7 @@  int bpf_prog_load(enum bpf_prog_type prog_type,
 	attr.line_info_cnt = OPTS_GET(opts, line_info_cnt, 0);
 
 	attr.fd_array = ptr_to_u64(OPTS_GET(opts, fd_array, NULL));
+	attr.fd_array_cnt = OPTS_GET(opts, fd_array_cnt, 0);
 
 	if (log_level) {
 		attr.log_buf = ptr_to_u64(log_buf);
diff --git a/tools/lib/bpf/bpf.h b/tools/lib/bpf/bpf.h
index a4a7b1ad1b63..435da95d2058 100644
--- a/tools/lib/bpf/bpf.h
+++ b/tools/lib/bpf/bpf.h
@@ -107,9 +107,12 @@  struct bpf_prog_load_opts {
 	 */
 	__u32 log_true_size;
 	__u32 token_fd;
+
+	/* if set, provides the length of fd_array */
+	__u32 fd_array_cnt;
 	size_t :0;
 };
-#define bpf_prog_load_opts__last_field token_fd
+#define bpf_prog_load_opts__last_field fd_array_cnt
 
 LIBBPF_API int bpf_prog_load(enum bpf_prog_type prog_type,
 			     const char *prog_name, const char *license,