From: Yonghong Song <yhs@fb.com>
To: Andrii Nakryiko <andriin@fb.com>, <bpf@vger.kernel.org>,
Martin KaFai Lau <kafai@fb.com>, <netdev@vger.kernel.org>
Cc: Alexei Starovoitov <ast@fb.com>,
Daniel Borkmann <daniel@iogearbox.net>, <kernel-team@fb.com>
Subject: [PATCH bpf-next v3 04/21] bpf: support bpf tracing/iter programs for BPF_LINK_UPDATE
Date: Wed, 6 May 2020 22:39:19 -0700 [thread overview]
Message-ID: <20200507053919.1542666-1-yhs@fb.com> (raw)
In-Reply-To: <20200507053915.1542140-1-yhs@fb.com>
Added BPF_LINK_UPDATE support for tracing/iter programs.
This way, a file based bpf iterator, which holds a reference
to the link, can have its bpf program updated without
creating new files.
Acked-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Yonghong Song <yhs@fb.com>
---
kernel/bpf/bpf_iter.c | 31 +++++++++++++++++++++++++++++++
1 file changed, 31 insertions(+)
diff --git a/kernel/bpf/bpf_iter.c b/kernel/bpf/bpf_iter.c
index 03f5832909db..0542a243b78c 100644
--- a/kernel/bpf/bpf_iter.c
+++ b/kernel/bpf/bpf_iter.c
@@ -23,6 +23,9 @@ struct bpf_iter_link {
static struct list_head targets = LIST_HEAD_INIT(targets);
static DEFINE_MUTEX(targets_mutex);
+/* protect bpf_iter_link changes */
+static DEFINE_MUTEX(link_mutex);
+
int bpf_iter_reg_target(struct bpf_iter_reg *reg_info)
{
struct bpf_iter_target_info *tinfo;
@@ -111,9 +114,37 @@ static void bpf_iter_link_dealloc(struct bpf_link *link)
kfree(iter_link);
}
+static int bpf_iter_link_replace(struct bpf_link *link,
+ struct bpf_prog *new_prog,
+ struct bpf_prog *old_prog)
+{
+ int ret = 0;
+
+ mutex_lock(&link_mutex);
+ if (old_prog && link->prog != old_prog) {
+ ret = -EPERM;
+ goto out_unlock;
+ }
+
+ if (link->prog->type != new_prog->type ||
+ link->prog->expected_attach_type != new_prog->expected_attach_type ||
+ link->prog->aux->attach_btf_id != new_prog->aux->attach_btf_id) {
+ ret = -EINVAL;
+ goto out_unlock;
+ }
+
+ old_prog = xchg(&link->prog, new_prog);
+ bpf_prog_put(old_prog);
+
+out_unlock:
+ mutex_unlock(&link_mutex);
+ return ret;
+}
+
static const struct bpf_link_ops bpf_iter_link_lops = {
.release = bpf_iter_link_release,
.dealloc = bpf_iter_link_dealloc,
+ .update_prog = bpf_iter_link_replace,
};
int bpf_iter_link_attach(const union bpf_attr *attr, struct bpf_prog *prog)
--
2.24.1
next prev parent reply other threads:[~2020-05-07 5:40 UTC|newest]
Thread overview: 45+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-05-07 5:39 [PATCH bpf-next v3 00/21] bpf: implement bpf iterator for kernel data Yonghong Song
2020-05-07 5:39 ` [PATCH bpf-next v3 01/21] bpf: implement an interface to register bpf_iter targets Yonghong Song
2020-05-08 18:18 ` Andrii Nakryiko
2020-05-07 5:39 ` [PATCH bpf-next v3 02/21] bpf: allow loading of a bpf_iter program Yonghong Song
2020-05-08 18:20 ` Andrii Nakryiko
2020-05-07 5:39 ` [PATCH bpf-next v3 03/21] bpf: support bpf tracing/iter programs for BPF_LINK_CREATE Yonghong Song
2020-05-08 18:24 ` Andrii Nakryiko
2020-05-09 1:36 ` Yonghong Song
2020-05-12 3:15 ` Andrii Nakryiko
2020-05-13 16:57 ` Yonghong Song
2020-05-07 5:39 ` Yonghong Song [this message]
2020-05-07 5:39 ` [PATCH bpf-next v3 05/21] bpf: implement bpf_seq_read() for bpf iterator Yonghong Song
2020-05-08 18:52 ` Andrii Nakryiko
2020-05-09 1:41 ` Yonghong Song
2020-05-07 5:39 ` [PATCH bpf-next v3 06/21] bpf: create anonymous " Yonghong Song
2020-05-08 18:57 ` Andrii Nakryiko
2020-05-07 5:39 ` [PATCH bpf-next v3 07/21] bpf: create file " Yonghong Song
2020-05-07 5:39 ` [PATCH bpf-next v3 08/21] bpf: implement common macros/helpers for target iterators Yonghong Song
2020-05-08 19:07 ` Andrii Nakryiko
2020-05-09 3:18 ` Yonghong Song
2020-05-12 3:16 ` Andrii Nakryiko
2020-05-07 5:39 ` [PATCH bpf-next v3 09/21] bpf: add bpf_map iterator Yonghong Song
2020-05-07 5:39 ` [PATCH bpf-next v3 10/21] net: bpf: add netlink and ipv6_route bpf_iter targets Yonghong Song
2020-05-08 19:17 ` Andrii Nakryiko
2020-05-07 5:39 ` [PATCH bpf-next v3 11/21] bpf: add task and task/file iterator targets Yonghong Song
2020-05-08 19:36 ` Andrii Nakryiko
2020-05-07 5:39 ` [PATCH bpf-next v3 12/21] bpf: add PTR_TO_BTF_ID_OR_NULL support Yonghong Song
2020-05-07 5:39 ` [PATCH bpf-next v3 13/21] bpf: add bpf_seq_printf and bpf_seq_write helpers Yonghong Song
2020-05-08 19:44 ` Andrii Nakryiko
2020-05-09 4:18 ` Yonghong Song
2020-05-09 5:30 ` Alexei Starovoitov
2020-05-09 6:04 ` Yonghong Song
2020-05-07 5:39 ` [PATCH bpf-next v3 14/21] bpf: handle spilled PTR_TO_BTF_ID properly when checking stack_boundary Yonghong Song
2020-05-07 5:39 ` [PATCH bpf-next v3 15/21] bpf: support variable length array in tracing programs Yonghong Song
2020-05-07 5:39 ` [PATCH bpf-next v3 16/21] tools/libbpf: add bpf_iter support Yonghong Song
2020-05-08 19:46 ` Andrii Nakryiko
2020-05-07 5:39 ` [PATCH bpf-next v3 17/21] tools/libpf: add offsetof/container_of macro in bpf_helpers.h Yonghong Song
2020-05-08 19:48 ` Andrii Nakryiko
2020-05-07 5:39 ` [PATCH bpf-next v3 18/21] tools/bpftool: add bpf_iter support for bptool Yonghong Song
2020-05-08 19:51 ` Andrii Nakryiko
2020-05-09 5:26 ` Yonghong Song
2020-05-07 5:39 ` [PATCH bpf-next v3 19/21] tools/bpf: selftests: add iterator programs for ipv6_route and netlink Yonghong Song
2020-05-07 5:39 ` [PATCH bpf-next v3 20/21] tools/bpf: selftests: add iter progs for bpf_map/task/task_file Yonghong Song
2020-05-07 5:39 ` [PATCH bpf-next v3 21/21] tools/bpf: selftests: add bpf_iter selftests Yonghong Song
2020-05-08 19:57 ` Andrii Nakryiko
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