libbpf: Use func name when pinning programs with LIBBPF_STRICT_SEC_NAME

We can't use section name anymore because they are not unique
and pinning objects with multiple programs with the same
progtype/secname will fail.

  [0] Closes: https://github.com/libbpf/libbpf/issues/273

Fixes: 33a2c75c55e2 ("libbpf: add internal pin_name")
Signed-off-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Reviewed-by: Quentin Monnet <quentin@isovalent.com>
Link: https://lore.kernel.org/bpf/20211021214814.1236114-2-sdf@google.com

diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index eb10244..604abe0 100644 (file)
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -285,7 +285,7 @@ struct bpf_program {
        size_t sub_insn_off;
 
        char *name;
-       /* sec_name with / replaced by _; makes recursive pinning
+       /* name with / replaced by _; makes recursive pinning
         * in bpf_object__pin_programs easier
         */
        char *pin_name;
@@ -618,7 +618,16 @@ static char *__bpf_program__pin_name(struct bpf_program *prog)
 {
        char *name, *p;
 
-       name = p = strdup(prog->sec_name);
+       if (libbpf_mode & LIBBPF_STRICT_SEC_NAME)
+               name = strdup(prog->name);
+       else
+               name = strdup(prog->sec_name);
+
+       if (!name)
+               return NULL;
+
+       p = name;
+
        while ((p = strchr(p, '/')))
                *p = '_';
 

diff --git a/tools/lib/bpf/libbpf_legacy.h b/tools/lib/bpf/libbpf_legacy.h
index 74e6f86..29ccafa 100644 (file)
--- a/tools/lib/bpf/libbpf_legacy.h
+++ b/tools/lib/bpf/libbpf_legacy.h
@@ -52,6 +52,9 @@ enum libbpf_strict_mode {
         * allowed, with LIBBPF_STRICT_SEC_PREFIX this will become
         * unrecognized by libbpf and would have to be just SEC("xdp") and
         * SEC("xdp") and SEC("perf_event").
+        *
+        * Note, in this mode the program pin path will be based on the
+        * function name instead of section name.
         */
        LIBBPF_STRICT_SEC_NAME = 0x04,