From: Roman Gushchin <[email protected]> Introduce bpf_map__attach_struct_ops_opts(), an extended version of bpf_map__attach_struct_ops(), which takes additional struct bpf_struct_ops_opts argument.
struct bpf_struct_ops_opts has the relative_fd member, which allows to pass an additional file descriptor argument. It can be used to attach struct ops maps to cgroups. Signed-off-by: Roman Gushchin <[email protected]> --- tools/lib/bpf/bpf.c | 8 ++++++++ tools/lib/bpf/libbpf.c | 18 ++++++++++++++++-- tools/lib/bpf/libbpf.h | 14 ++++++++++++++ tools/lib/bpf/libbpf.map | 1 + 4 files changed, 39 insertions(+), 2 deletions(-) diff --git a/tools/lib/bpf/bpf.c b/tools/lib/bpf/bpf.c index 5846de364209..84a53c594f48 100644 --- a/tools/lib/bpf/bpf.c +++ b/tools/lib/bpf/bpf.c @@ -884,6 +884,14 @@ int bpf_link_create(int prog_fd, int target_fd, if (!OPTS_ZEROED(opts, cgroup)) return libbpf_err(-EINVAL); break; + case BPF_STRUCT_OPS: + relative_fd = OPTS_GET(opts, cgroup.relative_fd, 0); + attr.link_create.cgroup.relative_fd = relative_fd; + attr.link_create.cgroup.expected_revision = + OPTS_GET(opts, cgroup.expected_revision, 0); + if (!OPTS_ZEROED(opts, cgroup)) + return libbpf_err(-EINVAL); + break; default: if (!OPTS_ZEROED(opts, flags)) return libbpf_err(-EINVAL); diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index 0c8bf0b5cce4..70a00da54ff5 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -13462,12 +13462,19 @@ static int bpf_link__detach_struct_ops(struct bpf_link *link) return close(link->fd); } -struct bpf_link *bpf_map__attach_struct_ops(const struct bpf_map *map) +struct bpf_link *bpf_map__attach_struct_ops_opts(const struct bpf_map *map, + const struct bpf_struct_ops_opts *opts) { + DECLARE_LIBBPF_OPTS(bpf_link_create_opts, link_opts); struct bpf_link_struct_ops *link; __u32 zero = 0; int err, fd; + if (!OPTS_VALID(opts, bpf_struct_ops_opts)) { + pr_warn("map '%s': invalid opts\n", map->name); + return libbpf_err_ptr(-EINVAL); + } + if (!bpf_map__is_struct_ops(map)) { pr_warn("map '%s': can't attach non-struct_ops map\n", map->name); return libbpf_err_ptr(-EINVAL); @@ -13503,7 +13510,9 @@ struct bpf_link *bpf_map__attach_struct_ops(const struct bpf_map *map) return &link->link; } - fd = bpf_link_create(map->fd, 0, BPF_STRUCT_OPS, NULL); + link_opts.cgroup.relative_fd = OPTS_GET(opts, relative_fd, 0); + + fd = bpf_link_create(map->fd, 0, BPF_STRUCT_OPS, &link_opts); if (fd < 0) { free(link); return libbpf_err_ptr(fd); @@ -13515,6 +13524,11 @@ struct bpf_link *bpf_map__attach_struct_ops(const struct bpf_map *map) return &link->link; } +struct bpf_link *bpf_map__attach_struct_ops(const struct bpf_map *map) +{ + return bpf_map__attach_struct_ops_opts(map, NULL); +} + /* * Swap the back struct_ops of a link with a new struct_ops map. */ diff --git a/tools/lib/bpf/libbpf.h b/tools/lib/bpf/libbpf.h index dfc37a615578..5aef44bcfcc2 100644 --- a/tools/lib/bpf/libbpf.h +++ b/tools/lib/bpf/libbpf.h @@ -920,6 +920,20 @@ bpf_program__attach_cgroup_opts(const struct bpf_program *prog, int cgroup_fd, struct bpf_map; LIBBPF_API struct bpf_link *bpf_map__attach_struct_ops(const struct bpf_map *map); + +struct bpf_struct_ops_opts { + /* size of this struct, for forward/backward compatibility */ + size_t sz; + __u32 flags; + __u32 relative_fd; + __u64 expected_revision; + size_t :0; +}; +#define bpf_struct_ops_opts__last_field expected_revision + +LIBBPF_API struct bpf_link * +bpf_map__attach_struct_ops_opts(const struct bpf_map *map, + const struct bpf_struct_ops_opts *opts); LIBBPF_API int bpf_link__update_map(struct bpf_link *link, const struct bpf_map *map); struct bpf_iter_attach_opts { diff --git a/tools/lib/bpf/libbpf.map b/tools/lib/bpf/libbpf.map index d18fbcea7578..4779190c97b6 100644 --- a/tools/lib/bpf/libbpf.map +++ b/tools/lib/bpf/libbpf.map @@ -454,4 +454,5 @@ LIBBPF_1.7.0 { bpf_prog_assoc_struct_ops; bpf_program__assoc_struct_ops; btf__permute; + bpf_map__attach_struct_ops_opts; } LIBBPF_1.6.0; -- 2.43.0
