diff options
Diffstat (limited to 'tools')
| -rw-r--r-- | tools/lib/bpf/libbpf.c | 58 |
1 files changed, 58 insertions, 0 deletions
diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index f022ac82e882..dffdd68b5e6b 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -24,6 +24,7 @@ #include <linux/kernel.h> #include <linux/bpf.h> #include <linux/btf.h> +#include <linux/filter.h> #include <linux/list.h> #include <linux/limits.h> #include <linux/perf_event.h> @@ -114,6 +115,11 @@ void libbpf_set_print(libbpf_print_fn_t warn, # define LIBBPF_ELF_C_READ_MMAP ELF_C_READ #endif +struct bpf_capabilities { + /* v4.14: kernel support for program & map names. */ + __u32 name:1; +}; + /* * bpf_prog should be a better name but it has been used in * linux/filter.h. @@ -160,6 +166,8 @@ struct bpf_program { void *func_info; __u32 func_info_rec_size; __u32 func_info_len; + + struct bpf_capabilities *caps; }; struct bpf_map { @@ -221,6 +229,8 @@ struct bpf_object { void *priv; bpf_object_clear_priv_t clear_priv; + struct bpf_capabilities caps; + char path[]; }; #define obj_elf_valid(o) ((o)->efile.elf) @@ -342,6 +352,7 @@ bpf_object__add_program(struct bpf_object *obj, void *data, size_t size, if (err) return err; + prog.caps = &obj->caps; progs = obj->programs; nr_progs = obj->nr_programs; @@ -1136,6 +1147,52 @@ err_free_new_name: } static int +bpf_object__probe_name(struct bpf_object *obj) +{ + struct bpf_load_program_attr attr; + char *cp, errmsg[STRERR_BUFSIZE]; + struct bpf_insn insns[] = { + BPF_MOV64_IMM(BPF_REG_0, 0), + BPF_EXIT_INSN(), + }; + int ret; + + /* make sure basic loading works */ + + memset(&attr, 0, sizeof(attr)); + attr.prog_type = BPF_PROG_TYPE_SOCKET_FILTER; + attr.insns = insns; + attr.insns_cnt = ARRAY_SIZE(insns); + attr.license = "GPL"; + + ret = bpf_load_program_xattr(&attr, NULL, 0); + if (ret < 0) { + cp = libbpf_strerror_r(errno, errmsg, sizeof(errmsg)); + pr_warning("Error in %s():%s(%d). Couldn't load basic 'r0 = 0' BPF program.\n", + __func__, cp, errno); + return -errno; + } + close(ret); + + /* now try the same program, but with the name */ + + attr.name = "test"; + ret = bpf_load_program_xattr(&attr, NULL, 0); + if (ret >= 0) { + obj->caps.name = 1; + close(ret); + } + + return 0; +} + +static int +bpf_object__probe_caps(struct bpf_object *obj) +{ + return bpf_object__probe_name(obj); +} + +static int bpf_object__create_maps(struct bpf_object *obj) { struct bpf_create_map_attr create_attr = {}; @@ -1708,6 +1765,7 @@ int bpf_object__load(struct bpf_object *obj) obj->loaded = true; + CHECK_ERR(bpf_object__probe_caps(obj), err, out); CHECK_ERR(bpf_object__create_maps(obj), err, out); CHECK_ERR(bpf_object__relocate(obj), err, out); CHECK_ERR(bpf_object__load_progs(obj), err, out); |