On Thu, Feb 20, 2020 at 9:53 AM KP Singh <kpsingh@xxxxxxxxxxxx> wrote:
>
> From: KP Singh <kpsingh@xxxxxxxxxx>
>
> Since BPF_PROG_TYPE_LSM uses the same attaching mechanism as
> BPF_PROG_TYPE_TRACING, the common logic is refactored into a static
> function bpf_program__attach_btf.
>
> A new API call bpf_program__attach_lsm is still added to avoid userspace
> conflicts if this ever changes in the future.
>
> Signed-off-by: KP Singh <kpsingh@xxxxxxxxxx>
> ---
> tools/lib/bpf/bpf.c | 3 ++-
> tools/lib/bpf/libbpf.c | 46 ++++++++++++++++++++++++++++++++--------
> tools/lib/bpf/libbpf.h | 4 ++++
> tools/lib/bpf/libbpf.map | 3 +++
> 4 files changed, 46 insertions(+), 10 deletions(-)
>
> diff --git a/tools/lib/bpf/bpf.c b/tools/lib/bpf/bpf.c
> index c6dafe563176..73220176728d 100644
> --- a/tools/lib/bpf/bpf.c
> +++ b/tools/lib/bpf/bpf.c
> @@ -235,7 +235,8 @@ int bpf_load_program_xattr(const struct bpf_load_program_attr *load_attr,
> memset(&attr, 0, sizeof(attr));
> attr.prog_type = load_attr->prog_type;
> attr.expected_attach_type = load_attr->expected_attach_type;
> - if (attr.prog_type == BPF_PROG_TYPE_STRUCT_OPS) {
> + if (attr.prog_type == BPF_PROG_TYPE_STRUCT_OPS ||
> + attr.prog_type == BPF_PROG_TYPE_LSM) {
> attr.attach_btf_id = load_attr->attach_btf_id;
> } else if (attr.prog_type == BPF_PROG_TYPE_TRACING ||
> attr.prog_type == BPF_PROG_TYPE_EXT) {
> diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
> index 514b1a524abb..d11139d5e76b 100644
> --- a/tools/lib/bpf/libbpf.c
> +++ b/tools/lib/bpf/libbpf.c
> @@ -2351,16 +2351,14 @@ static int bpf_object__finalize_btf(struct bpf_object *obj)
>
> static inline bool libbpf_prog_needs_vmlinux_btf(struct bpf_program *prog)
> {
> - if (prog->type == BPF_PROG_TYPE_STRUCT_OPS)
> + if (prog->type == BPF_PROG_TYPE_STRUCT_OPS ||
> + prog->type == BPF_PROG_TYPE_LSM)
> return true;
>
> /* BPF_PROG_TYPE_TRACING programs which do not attach to other programs
> * also need vmlinux BTF
> */
> - if (prog->type == BPF_PROG_TYPE_TRACING && !prog->attach_prog_fd)
> - return true;
> -
> - return false;
> + return prog->type == BPF_PROG_TYPE_TRACING && !prog->attach_prog_fd;
please keep this as is, it allows to add more logic easily, if necessary
> }
>
> static int bpf_object__load_vmlinux_btf(struct bpf_object *obj)
> @@ -4855,7 +4853,8 @@ load_program(struct bpf_program *prog, struct bpf_insn *insns, int insns_cnt,
> load_attr.insns = insns;
> load_attr.insns_cnt = insns_cnt;
> load_attr.license = license;
[...]
> -struct bpf_link *bpf_program__attach_trace(struct bpf_program *prog)
> +/* Common logic for all BPF program types that attach to a btf_id */
> +static struct bpf_link *bpf_program__attach_btf(struct bpf_program *prog)
> {
> char errmsg[STRERR_BUFSIZE];
> struct bpf_link_fd *link;
> @@ -7376,7 +7388,7 @@ struct bpf_link *bpf_program__attach_trace(struct bpf_program *prog)
> if (pfd < 0) {
> pfd = -errno;
> free(link);
> - pr_warn("program '%s': failed to attach to trace: %s\n",
> + pr_warn("program '%s': failed to attach to: %s\n",
to attach to ... what?.. %s at the end is just an error message
> bpf_program__title(prog, false),
> libbpf_strerror_r(pfd, errmsg, sizeof(errmsg)));
> return ERR_PTR(pfd);
> @@ -7385,10 +7397,26 @@ struct bpf_link *bpf_program__attach_trace(struct bpf_program *prog)
> return (struct bpf_link *)link;
> }
>
[...]
> --- a/tools/lib/bpf/libbpf.map
> +++ b/tools/lib/bpf/libbpf.map
> @@ -227,10 +227,13 @@ LIBBPF_0.0.7 {
> bpf_probe_large_insn_limit;
> bpf_prog_attach_xattr;
> bpf_program__attach;
> + bpf_program__attach_lsm;
> bpf_program__name;
> bpf_program__is_extension;
> + bpf_program__is_lsm;
> bpf_program__is_struct_ops;
> bpf_program__set_extension;
> + bpf_program__set_lsm;
please make sure to add to 0.0.8 version for new revision
> bpf_program__set_struct_ops;
> btf__align_of;
> libbpf_find_kernel_btf;
> --
> 2.20.1
>
