libbpf: Support detecting and attaching of writable tracepoint program

Program on writable tracepoint is BPF_PROG_TYPE_RAW_TRACEPOINT_WRITABLE,
but its attachment is the same as BPF_PROG_TYPE_RAW_TRACEPOINT.

Signed-off-by: Hou Tao <houtao1@huawei.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20211004094857.30868-3-hotforest@gmail.com

diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index ed313fd491bd26c660105747c81285536c2aab03..ae0889bebe329ab6082cf21f6d20ae040e8919ab 100644 (file)
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -8077,6 +8077,8 @@ static const struct bpf_sec_def section_defs[] = {
        SEC_DEF("tp/",                  TRACEPOINT, 0, SEC_NONE, attach_tp),
        SEC_DEF("raw_tracepoint/",      RAW_TRACEPOINT, 0, SEC_NONE, attach_raw_tp),
        SEC_DEF("raw_tp/",              RAW_TRACEPOINT, 0, SEC_NONE, attach_raw_tp),
+       SEC_DEF("raw_tracepoint.w/",    RAW_TRACEPOINT_WRITABLE, 0, SEC_NONE, attach_raw_tp),
+       SEC_DEF("raw_tp.w/",            RAW_TRACEPOINT_WRITABLE, 0, SEC_NONE, attach_raw_tp),
        SEC_DEF("tp_btf/",              TRACING, BPF_TRACE_RAW_TP, SEC_ATTACH_BTF, attach_trace),
        SEC_DEF("fentry/",              TRACING, BPF_TRACE_FENTRY, SEC_ATTACH_BTF, attach_trace),
        SEC_DEF("fmod_ret/",            TRACING, BPF_MODIFY_RETURN, SEC_ATTACH_BTF, attach_trace),
@@ -9846,12 +9848,26 @@ struct bpf_link *bpf_program__attach_raw_tracepoint(const struct bpf_program *pr
 
 static struct bpf_link *attach_raw_tp(const struct bpf_program *prog, long cookie)
 {
-       const char *tp_name;
+       static const char *const prefixes[] = {
+               "raw_tp/",
+               "raw_tracepoint/",
+               "raw_tp.w/",
+               "raw_tracepoint.w/",
+       };
+       size_t i;
+       const char *tp_name = NULL;
 
-       if (str_has_pfx(prog->sec_name, "raw_tp/"))
-               tp_name = prog->sec_name + sizeof("raw_tp/") - 1;
-       else
-               tp_name = prog->sec_name + sizeof("raw_tracepoint/") - 1;
+       for (i = 0; i < ARRAY_SIZE(prefixes); i++) {
+               if (str_has_pfx(prog->sec_name, prefixes[i])) {
+                       tp_name = prog->sec_name + strlen(prefixes[i]);
+                       break;
+               }
+       }
+       if (!tp_name) {
+               pr_warn("prog '%s': invalid section name '%s'\n",
+                       prog->name, prog->sec_name);
+               return libbpf_err_ptr(-EINVAL);
+       }
 
        return bpf_program__attach_raw_tracepoint(prog, tp_name);
 }