tools lib bpf: New API to adjust type of a BPF program

Add 4 new APIs to adjust and query the type of a BPF program.
Load program according to type set by caller. Default is set to
BPF_PROG_TYPE_KPROBE.

Signed-off-by: Wang Nan <wangnan0@huawei.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Zefan Li <lizefan@huawei.com>
Cc: pi3orama@163.com
Link: http://lkml.kernel.org/r/1468406646-21642-2-git-send-email-wangnan0@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index 3dcda9e..4751936 100644 (file)
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -158,6 +158,7 @@ struct bpf_program {
        char *section_name;
        struct bpf_insn *insns;
        size_t insns_cnt;
+       enum bpf_prog_type type;
 
        struct {
                int insn_idx;
@@ -299,6 +300,7 @@ bpf_program__init(void *data, size_t size, char *name, int idx,
        prog->idx = idx;
        prog->instances.fds = NULL;
        prog->instances.nr = -1;
+       prog->type = BPF_PROG_TYPE_KPROBE;
 
        return 0;
 errout:
@@ -894,8 +896,8 @@ static int bpf_object__collect_reloc(struct bpf_object *obj)
 }
 
 static int
-load_program(struct bpf_insn *insns, int insns_cnt,
-            char *license, u32 kern_version, int *pfd)
+load_program(enum bpf_prog_type type, struct bpf_insn *insns,
+            int insns_cnt, char *license, u32 kern_version, int *pfd)
 {
        int ret;
        char *log_buf;
@@ -907,9 +909,8 @@ load_program(struct bpf_insn *insns, int insns_cnt,
        if (!log_buf)
                pr_warning("Alloc log buffer for bpf loader error, continue without log\n");
 
-       ret = bpf_load_program(BPF_PROG_TYPE_KPROBE, insns,
-                              insns_cnt, license, kern_version,
-                              log_buf, BPF_LOG_BUF_SIZE);
+       ret = bpf_load_program(type, insns, insns_cnt, license,
+                              kern_version, log_buf, BPF_LOG_BUF_SIZE);
 
        if (ret >= 0) {
                *pfd = ret;
@@ -968,7 +969,7 @@ bpf_program__load(struct bpf_program *prog,
                        pr_warning("Program '%s' is inconsistent: nr(%d) != 1\n",
                                   prog->section_name, prog->instances.nr);
                }
-               err = load_program(prog->insns, prog->insns_cnt,
+               err = load_program(prog->type, prog->insns, prog->insns_cnt,
                                   license, kern_version, &fd);
                if (!err)
                        prog->instances.fds[0] = fd;
@@ -997,7 +998,7 @@ bpf_program__load(struct bpf_program *prog,
                        continue;
                }
 
-               err = load_program(result.new_insn_ptr,
+               err = load_program(prog->type, result.new_insn_ptr,
                                   result.new_insn_cnt,
                                   license, kern_version, &fd);
 
@@ -1316,6 +1317,44 @@ int bpf_program__nth_fd(struct bpf_program *prog, int n)
        return fd;
 }
 
+static void bpf_program__set_type(struct bpf_program *prog,
+                                 enum bpf_prog_type type)
+{
+       prog->type = type;
+}
+
+int bpf_program__set_tracepoint(struct bpf_program *prog)
+{
+       if (!prog)
+               return -EINVAL;
+       bpf_program__set_type(prog, BPF_PROG_TYPE_TRACEPOINT);
+       return 0;
+}
+
+int bpf_program__set_kprobe(struct bpf_program *prog)
+{
+       if (!prog)
+               return -EINVAL;
+       bpf_program__set_type(prog, BPF_PROG_TYPE_KPROBE);
+       return 0;
+}
+
+static bool bpf_program__is_type(struct bpf_program *prog,
+                                enum bpf_prog_type type)
+{
+       return prog ? (prog->type == type) : false;
+}
+
+bool bpf_program__is_tracepoint(struct bpf_program *prog)
+{
+       return bpf_program__is_type(prog, BPF_PROG_TYPE_TRACEPOINT);
+}
+
+bool bpf_program__is_kprobe(struct bpf_program *prog)
+{
+       return bpf_program__is_type(prog, BPF_PROG_TYPE_KPROBE);
+}
+
 int bpf_map__fd(struct bpf_map *map)
 {
        return map ? map->fd : -EINVAL;

diff --git a/tools/lib/bpf/libbpf.h b/tools/lib/bpf/libbpf.h
index f392c5e..eb2a4c4 100644 (file)
--- a/tools/lib/bpf/libbpf.h
+++ b/tools/lib/bpf/libbpf.h
@@ -164,6 +164,15 @@ int bpf_program__set_prep(struct bpf_program *prog, int nr_instance,
 
 int bpf_program__nth_fd(struct bpf_program *prog, int n);
 
+/*
+ * Adjust type of bpf program. Default is kprobe.
+ */
+int bpf_program__set_tracepoint(struct bpf_program *prog);
+int bpf_program__set_kprobe(struct bpf_program *prog);
+
+bool bpf_program__is_tracepoint(struct bpf_program *prog);
+bool bpf_program__is_kprobe(struct bpf_program *prog);
+
 /*
  * We don't need __attribute__((packed)) now since it is
  * unnecessary for 'bpf_map_def' because they are all aligned.