libbpf: Add support for u[ret]probe.multi[.s] program sections

Adding support for several uprobe_multi program sections
to allow auto attach of multi_uprobe programs.

Acked-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/r/20230809083440.3209381-16-jolsa@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index 0789c704fe766ee18624759853e787cac39a9ca1..c9c390542040cdb54ec042cda5dd7cbe4f9cba26 100644 (file)
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -8701,6 +8701,7 @@ static int attach_tp(const struct bpf_program *prog, long cookie, struct bpf_lin
 static int attach_raw_tp(const struct bpf_program *prog, long cookie, struct bpf_link **link);
 static int attach_trace(const struct bpf_program *prog, long cookie, struct bpf_link **link);
 static int attach_kprobe_multi(const struct bpf_program *prog, long cookie, struct bpf_link **link);
+static int attach_uprobe_multi(const struct bpf_program *prog, long cookie, struct bpf_link **link);
 static int attach_lsm(const struct bpf_program *prog, long cookie, struct bpf_link **link);
 static int attach_iter(const struct bpf_program *prog, long cookie, struct bpf_link **link);
 
@@ -8716,6 +8717,10 @@ static const struct bpf_sec_def section_defs[] = {
        SEC_DEF("uretprobe.s+",         KPROBE, 0, SEC_SLEEPABLE, attach_uprobe),
        SEC_DEF("kprobe.multi+",        KPROBE, BPF_TRACE_KPROBE_MULTI, SEC_NONE, attach_kprobe_multi),
        SEC_DEF("kretprobe.multi+",     KPROBE, BPF_TRACE_KPROBE_MULTI, SEC_NONE, attach_kprobe_multi),
+       SEC_DEF("uprobe.multi+",        KPROBE, BPF_TRACE_UPROBE_MULTI, SEC_NONE, attach_uprobe_multi),
+       SEC_DEF("uretprobe.multi+",     KPROBE, BPF_TRACE_UPROBE_MULTI, SEC_NONE, attach_uprobe_multi),
+       SEC_DEF("uprobe.multi.s+",      KPROBE, BPF_TRACE_UPROBE_MULTI, SEC_SLEEPABLE, attach_uprobe_multi),
+       SEC_DEF("uretprobe.multi.s+",   KPROBE, BPF_TRACE_UPROBE_MULTI, SEC_SLEEPABLE, attach_uprobe_multi),
        SEC_DEF("ksyscall+",            KPROBE, 0, SEC_NONE, attach_ksyscall),
        SEC_DEF("kretsyscall+",         KPROBE, 0, SEC_NONE, attach_ksyscall),
        SEC_DEF("usdt+",                KPROBE, 0, SEC_NONE, attach_usdt),
@@ -10922,6 +10927,37 @@ static int attach_kprobe_multi(const struct bpf_program *prog, long cookie, stru
        return libbpf_get_error(*link);
 }
 
+static int attach_uprobe_multi(const struct bpf_program *prog, long cookie, struct bpf_link **link)
+{
+       char *probe_type = NULL, *binary_path = NULL, *func_name = NULL;
+       LIBBPF_OPTS(bpf_uprobe_multi_opts, opts);
+       int n, ret = -EINVAL;
+
+       *link = NULL;
+
+       n = sscanf(prog->sec_name, "%m[^/]/%m[^:]:%ms",
+                  &probe_type, &binary_path, &func_name);
+       switch (n) {
+       case 1:
+               /* handle SEC("u[ret]probe") - format is valid, but auto-attach is impossible. */
+               ret = 0;
+               break;
+       case 3:
+               opts.retprobe = strcmp(probe_type, "uretprobe.multi") == 0;
+               *link = bpf_program__attach_uprobe_multi(prog, -1, binary_path, func_name, &opts);
+               ret = libbpf_get_error(*link);
+               break;
+       default:
+               pr_warn("prog '%s': invalid format of section definition '%s'\n", prog->name,
+                       prog->sec_name);
+               break;
+       }
+       free(probe_type);
+       free(binary_path);
+       free(func_name);
+       return ret;
+}
+
 static void gen_uprobe_legacy_event_name(char *buf, size_t buf_sz,
                                         const char *binary_path, uint64_t offset)
 {