From 395fc4fa33e98944384d0d6c8b3ecd9fb4b50d00 Mon Sep 17 00:00:00 2001 From: Joe Burton Date: Fri, 29 Jul 2022 20:27:27 +0000 Subject: [PATCH] libbpf: Add bpf_obj_get_opts() Add an extensible variant of bpf_obj_get() capable of setting the `file_flags` parameter. This parameter is needed to enable unprivileged access to BPF maps. Without a method like this, users must manually make the syscall. Signed-off-by: Joe Burton Signed-off-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20220729202727.3311806-1-jevburton.kernel@gmail.com --- tools/lib/bpf/bpf.c | 9 +++++++++ tools/lib/bpf/bpf.h | 11 +++++++++++ tools/lib/bpf/libbpf.map | 1 + 3 files changed, 21 insertions(+) diff --git a/tools/lib/bpf/bpf.c b/tools/lib/bpf/bpf.c index 5eb0df90eb2b..efcc06dafbd9 100644 --- a/tools/lib/bpf/bpf.c +++ b/tools/lib/bpf/bpf.c @@ -579,11 +579,20 @@ int bpf_obj_pin(int fd, const char *pathname) int bpf_obj_get(const char *pathname) { + return bpf_obj_get_opts(pathname, NULL); +} + +int bpf_obj_get_opts(const char *pathname, const struct bpf_obj_get_opts *opts) +{ union bpf_attr attr; int fd; + if (!OPTS_VALID(opts, bpf_obj_get_opts)) + return libbpf_err(-EINVAL); + memset(&attr, 0, sizeof(attr)); attr.pathname = ptr_to_u64((void *)pathname); + attr.file_flags = OPTS_GET(opts, file_flags, 0); fd = sys_bpf_fd(BPF_OBJ_GET, &attr, sizeof(attr)); return libbpf_err_errno(fd); diff --git a/tools/lib/bpf/bpf.h b/tools/lib/bpf/bpf.h index 88a7cc4bd76f..9c50beabdd14 100644 --- a/tools/lib/bpf/bpf.h +++ b/tools/lib/bpf/bpf.h @@ -270,8 +270,19 @@ LIBBPF_API int bpf_map_update_batch(int fd, const void *keys, const void *values __u32 *count, const struct bpf_map_batch_opts *opts); +struct bpf_obj_get_opts { + size_t sz; /* size of this struct for forward/backward compatibility */ + + __u32 file_flags; + + size_t :0; +}; +#define bpf_obj_get_opts__last_field file_flags + LIBBPF_API int bpf_obj_pin(int fd, const char *pathname); LIBBPF_API int bpf_obj_get(const char *pathname); +LIBBPF_API int bpf_obj_get_opts(const char *pathname, + const struct bpf_obj_get_opts *opts); struct bpf_prog_attach_opts { size_t sz; /* size of this struct for forward/backward compatibility */ diff --git a/tools/lib/bpf/libbpf.map b/tools/lib/bpf/libbpf.map index 0625adb9e888..119e6e1ea7f1 100644 --- a/tools/lib/bpf/libbpf.map +++ b/tools/lib/bpf/libbpf.map @@ -355,6 +355,7 @@ LIBBPF_0.8.0 { LIBBPF_1.0.0 { global: + bpf_obj_get_opts; bpf_prog_query_opts; bpf_program__attach_ksyscall; btf__add_enum64; -- 2.11.0