From: Hangbin Liu <liuhangbin@gmail.com>
To: bpf@vger.kernel.org
Cc: "Alexei Starovoitov" <ast@kernel.org>,
"Daniel Borkmann" <daniel@iogearbox.net>,
"Song Liu" <songliubraving@fb.com>, "Yonghong Song" <yhs@fb.com>,
"Andrii Nakryiko" <andriin@fb.com>,
netdev@vger.kernel.org,
"Toke Høiland-Jørgensen" <toke@redhat.com>,
"Hangbin Liu" <liuhangbin@gmail.com>,
"Andrii Nakryiko" <andrii.nakryiko@gmail.com>
Subject: [PATCH libbpf] libbpf: check if pin_path was set even map fd exist
Date: Fri, 2 Oct 2020 15:57:50 +0800 [thread overview]
Message-ID: <20201002075750.1978298-1-liuhangbin@gmail.com> (raw)
Say a user reuse map fd after creating a map manually and set the
pin_path, then load the object via libbpf.
In libbpf bpf_object__create_maps(), bpf_object__reuse_map() will
return 0 if there is no pinned map in map->pin_path. Then after
checking if map fd exist, we should also check if pin_path was set
and do bpf_map__pin() instead of continue the loop.
Fix it by creating map if fd not exist and continue checking pin_path
after that.
Suggested-by: Andrii Nakryiko <andrii.nakryiko@gmail.com>
Signed-off-by: Hangbin Liu <liuhangbin@gmail.com>
---
tools/lib/bpf/libbpf.c | 75 +++++++++++++++++++++---------------------
1 file changed, 37 insertions(+), 38 deletions(-)
diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index e493d6048143..d4149585a76c 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -3861,50 +3861,49 @@ bpf_object__create_maps(struct bpf_object *obj)
}
}
- if (map->fd >= 0) {
- pr_debug("map '%s': skipping creation (preset fd=%d)\n",
- map->name, map->fd);
- continue;
- }
-
- err = bpf_object__create_map(obj, map);
- if (err)
- goto err_out;
-
- pr_debug("map '%s': created successfully, fd=%d\n", map->name,
- map->fd);
-
- if (bpf_map__is_internal(map)) {
- err = bpf_object__populate_internal_map(obj, map);
- if (err < 0) {
- zclose(map->fd);
+ if (map->fd < 0) {
+ err = bpf_object__create_map(obj, map);
+ if (err)
goto err_out;
- }
- }
-
- if (map->init_slots_sz) {
- for (j = 0; j < map->init_slots_sz; j++) {
- const struct bpf_map *targ_map;
- int fd;
- if (!map->init_slots[j])
- continue;
+ pr_debug("map '%s': created successfully, fd=%d\n", map->name,
+ map->fd);
- targ_map = map->init_slots[j];
- fd = bpf_map__fd(targ_map);
- err = bpf_map_update_elem(map->fd, &j, &fd, 0);
- if (err) {
- err = -errno;
- pr_warn("map '%s': failed to initialize slot [%d] to map '%s' fd=%d: %d\n",
- map->name, j, targ_map->name,
- fd, err);
+ if (bpf_map__is_internal(map)) {
+ err = bpf_object__populate_internal_map(obj, map);
+ if (err < 0) {
+ zclose(map->fd);
goto err_out;
}
- pr_debug("map '%s': slot [%d] set to map '%s' fd=%d\n",
- map->name, j, targ_map->name, fd);
}
- zfree(&map->init_slots);
- map->init_slots_sz = 0;
+
+ if (map->init_slots_sz) {
+ for (j = 0; j < map->init_slots_sz; j++) {
+ const struct bpf_map *targ_map;
+ int fd;
+
+ if (!map->init_slots[j])
+ continue;
+
+ targ_map = map->init_slots[j];
+ fd = bpf_map__fd(targ_map);
+ err = bpf_map_update_elem(map->fd, &j, &fd, 0);
+ if (err) {
+ err = -errno;
+ pr_warn("map '%s': failed to initialize slot [%d] to map '%s' fd=%d: %d\n",
+ map->name, j, targ_map->name,
+ fd, err);
+ goto err_out;
+ }
+ pr_debug("map '%s': slot [%d] set to map '%s' fd=%d\n",
+ map->name, j, targ_map->name, fd);
+ }
+ zfree(&map->init_slots);
+ map->init_slots_sz = 0;
+ }
+ } else {
+ pr_debug("map '%s': skipping creation (preset fd=%d)\n",
+ map->name, map->fd);
}
if (map->pin_path && !map->pinned) {
--
2.25.4
next reply other threads:[~2020-10-02 7:58 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-10-02 7:57 Hangbin Liu [this message]
2020-10-02 11:49 ` [PATCH libbpf] libbpf: check if pin_path was set even map fd exist Maciej Fijalkowski
2020-10-02 18:13 ` Andrii Nakryiko
2020-10-02 18:11 ` Andrii Nakryiko
2020-10-03 8:55 ` [PATCHv2 bpf 0/3] Fix pining maps after reuse map fd Hangbin Liu
2020-10-03 8:55 ` [PATCHv2 bpf 1/3] libbpf: close map fd if init map slots failed Hangbin Liu
2020-10-05 21:21 ` Andrii Nakryiko
2020-10-03 8:55 ` [PATCHv2 bpf 2/3] libbpf: check if pin_path was set even map fd exist Hangbin Liu
2020-10-05 21:22 ` Andrii Nakryiko
2020-10-03 8:55 ` [PATCHv2 bpf 3/3] selftest/bpf: test pinning map with reused map fd Hangbin Liu
2020-10-05 21:28 ` Andrii Nakryiko
2020-10-06 2:13 ` [PATCHv3 bpf 0/3] Fix pining maps after reuse " Hangbin Liu
2020-10-06 2:13 ` [PATCHv3 bpf 1/3] libbpf: close map fd if init map slots failed Hangbin Liu
2020-10-06 2:13 ` [PATCHv3 bpf 2/3] libbpf: check if pin_path was set even map fd exist Hangbin Liu
2020-10-06 2:13 ` [PATCHv3 bpf 3/3] selftest/bpf: test pinning map with reused map fd Hangbin Liu
2020-10-06 3:26 ` Andrii Nakryiko
2020-10-06 18:40 ` [PATCHv3 bpf 0/3] Fix pining maps after reuse " patchwork-bot+bpf
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