bpf: libbpf: remove map name retry from bpf_create_map_xattr

Instead, check for a newly created caps.name bpf_object capability.
If kernel doesn't support names, don't specify the attribute.

See commit 23499442c319 ("bpf: libbpf: retry map creation without
the name") for rationale.

Signed-off-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

diff --git a/tools/lib/bpf/bpf.c b/tools/lib/bpf/bpf.c
index 836447bb4f143cc75276872b04fcf78bbc92d754..ce182219459003c4079b8a1f5a5692c49887f4f5 100644 (file)
--- a/tools/lib/bpf/bpf.c
+++ b/tools/lib/bpf/bpf.c
@@ -69,7 +69,6 @@ int bpf_create_map_xattr(const struct bpf_create_map_attr *create_attr)
 {
        __u32 name_len = create_attr->name ? strlen(create_attr->name) : 0;
        union bpf_attr attr;
-       int ret;
 
        memset(&attr, '\0', sizeof(attr));
 
@@ -87,15 +86,7 @@ int bpf_create_map_xattr(const struct bpf_create_map_attr *create_attr)
        attr.map_ifindex = create_attr->map_ifindex;
        attr.inner_map_fd = create_attr->inner_map_fd;
 
-       ret = sys_bpf(BPF_MAP_CREATE, &attr, sizeof(attr));
-       if (ret < 0 && errno == EINVAL && create_attr->name) {
-               /* Retry the same syscall, but without the name.
-                * Pre v4.14 kernels don't support map names.
-                */
-               memset(attr.map_name, 0, sizeof(attr.map_name));
-               return sys_bpf(BPF_MAP_CREATE, &attr, sizeof(attr));
-       }
-       return ret;
+       return sys_bpf(BPF_MAP_CREATE, &attr, sizeof(attr));
 }
 
 int bpf_create_map_node(enum bpf_map_type map_type, const char *name,

diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index dffdd68b5e6bebe6222eb913357c09a82140d646..f28e64dd8b5a5316e801ea1dce2ce5da7199a517 100644 (file)
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -1211,7 +1211,8 @@ bpf_object__create_maps(struct bpf_object *obj)
                        continue;
                }
 
-               create_attr.name = map->name;
+               if (obj->caps.name)
+                       create_attr.name = map->name;
                create_attr.map_ifindex = map->map_ifindex;
                create_attr.map_type = def->type;
                create_attr.map_flags = def->map_flags;