netdev - [PATCH v2 bpf]: libbpf: fixing leak when kernel does not support btf

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Message-Id: <20190308040331.18774-1-tehnerd@tehnerd.com>
Date:   Fri,  8 Mar 2019 04:03:31 +0000
From:   "Nikita V. Shirokov" <tehnerd@...nerd.com>
To:     Alexei Starovoitov <ast@...nel.org>,
        Daniel Borkmann <daniel@...earbox.net>,
        Yonghong Song <yhs@...com>
Cc:     netdev@...r.kernel.org, "Nikita V . Shirokov" <tehnerd@...nerd.com>
Subject: [PATCH v2 bpf]: libbpf: fixing leak when kernel does not support btf

we could end up in situation when we have object file w/ all btf
info but kernel does not support btf yet. in this situation currently
libbpf just set obj->btf to NULL w/o freeing it first.
this patch if fixing it by making sure to run btf__free first

v1->v2:
 - adding netdev to cc

Signed-off-by: Nikita V. Shirokov <tehnerd@...nerd.com>
---
 tools/lib/bpf/libbpf.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index f5eb60379c8d..d5b830d60601 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -838,6 +838,8 @@ static int bpf_object__elf_collect(struct bpf_object *obj, int flags)
 			if (IS_ERR(obj->btf) || btf__load(obj->btf)) {
 				pr_warning("Error loading ELF section %s: %ld. Ignored and continue.\n",
 					   BTF_ELF_SEC, PTR_ERR(obj->btf));
+				if (!IS_ERR(obj->btf))
+					btf__free(obj->btf);
 				obj->btf = NULL;
 			}
 		} else if (strcmp(name, BTF_EXT_ELF_SEC) == 0) {
-- 
2.17.1