From: Andrii Nakryiko <andrii@kernel.org>
Date: Sun, 15 Aug 2021 00:06:01 -0700
Subject: libbpf: Remove unused bpf_link's destroy operation, but add dealloc
Patch-mainline: v5.15-rc1
Git-commit: d88b71d4a91669f0b06693cd094dcd68f67ac58d
References: jsc#PED-1377

bpf_link->destroy() isn't used by any code, so remove it. Instead, add ability
to override deallocation procedure, with default doing plain free(link). This
is necessary for cases when we want to "subclass" struct bpf_link to keep
extra information, as is the case in the next patch adding struct
bpf_link_perf.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20210815070609.987780-9-andrii@kernel.org
Acked-by: Shung-Hsi Yu <shung-hsi.yu@suse.com>
---
 tools/lib/bpf/libbpf.c |    9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -8810,7 +8810,7 @@ int bpf_prog_load_xattr(const struct bpf
 
 struct bpf_link {
 	int (*detach)(struct bpf_link *link);
-	int (*destroy)(struct bpf_link *link);
+	void (*dealloc)(struct bpf_link *link);
 	char *pin_path;		/* NULL, if not pinned */
 	int fd;			/* hook FD, -1 if not applicable */
 	bool disconnected;
@@ -8849,11 +8849,12 @@ int bpf_link__destroy(struct bpf_link *l
 
 	if (!link->disconnected && link->detach)
 		err = link->detach(link);
-	if (link->destroy)
-		link->destroy(link);
 	if (link->pin_path)
 		free(link->pin_path);
-	free(link);
+	if (link->dealloc)
+		link->dealloc(link);
+	else
+		free(link);
 
 	return libbpf_err(err);
 }