From: Jiri Olsa <jolsa@kernel.org>
To: Alexei Starovoitov <ast@kernel.org>,
Daniel Borkmann <daniel@iogearbox.net>,
Andrii Nakryiko <andrii@kernel.org>
Cc: bpf@vger.kernel.org, linux-trace-kernel@vger.kernel.org,
Martin KaFai Lau <kafai@fb.com>,
Eduard Zingerman <eddyz87@gmail.com>,
Song Liu <songliubraving@fb.com>, Yonghong Song <yhs@fb.com>,
Menglong Dong <menglong8.dong@gmail.com>,
Steven Rostedt <rostedt@kernel.org>
Subject: [PATCHv5 bpf-next 07/28] bpf: Add bpf_trampoline_add/remove_prog functions
Date: Fri, 17 Apr 2026 21:24:41 +0200 [thread overview]
Message-ID: <20260417192502.194548-8-jolsa@kernel.org> (raw)
In-Reply-To: <20260417192502.194548-1-jolsa@kernel.org>
Separate bpf_trampoline_add/remove_prog functions from
__bpf_trampoline_link/unlink functions to be able to add/remove
trampoline programs without the image being updated in following
changes. No functional change is intended.
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
---
kernel/bpf/trampoline.c | 108 +++++++++++++++++++++++-----------------
1 file changed, 61 insertions(+), 47 deletions(-)
diff --git a/kernel/bpf/trampoline.c b/kernel/bpf/trampoline.c
index ad4ddb62d22f..71e5a121c2fd 100644
--- a/kernel/bpf/trampoline.c
+++ b/kernel/bpf/trampoline.c
@@ -820,41 +820,16 @@ static int bpf_freplace_check_tgt_prog(struct bpf_prog *tgt_prog)
return 0;
}
-static int __bpf_trampoline_link_prog(struct bpf_tramp_link *link,
- struct bpf_trampoline *tr,
- struct bpf_prog *tgt_prog,
- const struct bpf_trampoline_ops *ops,
- void *data)
+static int bpf_trampoline_add_prog(struct bpf_trampoline *tr,
+ struct bpf_tramp_link *link,
+ int cnt)
{
struct bpf_fsession_link *fslink = NULL;
enum bpf_tramp_prog_type kind;
struct bpf_tramp_link *link_exiting;
struct hlist_head *prog_list;
- int err = 0;
- int cnt = 0, i;
kind = bpf_attach_type_to_tramp(link->link.prog);
- if (tr->extension_prog)
- /* cannot attach fentry/fexit if extension prog is attached.
- * cannot overwrite extension prog either.
- */
- return -EBUSY;
-
- for (i = 0; i < BPF_TRAMP_MAX; i++)
- cnt += tr->progs_cnt[i];
-
- if (kind == BPF_TRAMP_REPLACE) {
- /* Cannot attach extension if fentry/fexit are in use. */
- if (cnt)
- return -EBUSY;
- err = bpf_freplace_check_tgt_prog(tgt_prog);
- if (err)
- return err;
- tr->extension_prog = link->link.prog;
- return bpf_arch_text_poke(tr->func.addr, BPF_MOD_NOP,
- BPF_MOD_JUMP, NULL,
- link->link.prog->bpf_func);
- }
if (kind == BPF_TRAMP_FSESSION) {
prog_list = &tr->progs_hlist[BPF_TRAMP_FENTRY];
cnt++;
@@ -882,17 +857,64 @@ static int __bpf_trampoline_link_prog(struct bpf_tramp_link *link,
} else {
tr->progs_cnt[kind]++;
}
- err = bpf_trampoline_update(tr, true /* lock_direct_mutex */, ops, data);
- if (err) {
- hlist_del_init(&link->tramp_hlist);
- if (kind == BPF_TRAMP_FSESSION) {
- tr->progs_cnt[BPF_TRAMP_FENTRY]--;
- hlist_del_init(&fslink->fexit.tramp_hlist);
- tr->progs_cnt[BPF_TRAMP_FEXIT]--;
- } else {
- tr->progs_cnt[kind]--;
- }
+ return 0;
+}
+
+static void bpf_trampoline_remove_prog(struct bpf_trampoline *tr,
+ struct bpf_tramp_link *link)
+{
+ struct bpf_fsession_link *fslink;
+ enum bpf_tramp_prog_type kind;
+
+ kind = bpf_attach_type_to_tramp(link->link.prog);
+ if (kind == BPF_TRAMP_FSESSION) {
+ fslink = container_of(link, struct bpf_fsession_link, link.link);
+ hlist_del_init(&fslink->fexit.tramp_hlist);
+ tr->progs_cnt[BPF_TRAMP_FEXIT]--;
+ kind = BPF_TRAMP_FENTRY;
+ }
+ hlist_del_init(&link->tramp_hlist);
+ tr->progs_cnt[kind]--;
+}
+
+static int __bpf_trampoline_link_prog(struct bpf_tramp_link *link,
+ struct bpf_trampoline *tr,
+ struct bpf_prog *tgt_prog,
+ const struct bpf_trampoline_ops *ops,
+ void *data)
+{
+ enum bpf_tramp_prog_type kind;
+ int err = 0;
+ int cnt = 0, i;
+
+ kind = bpf_attach_type_to_tramp(link->link.prog);
+ if (tr->extension_prog)
+ /* cannot attach fentry/fexit if extension prog is attached.
+ * cannot overwrite extension prog either.
+ */
+ return -EBUSY;
+
+ for (i = 0; i < BPF_TRAMP_MAX; i++)
+ cnt += tr->progs_cnt[i];
+
+ if (kind == BPF_TRAMP_REPLACE) {
+ /* Cannot attach extension if fentry/fexit are in use. */
+ if (cnt)
+ return -EBUSY;
+ err = bpf_freplace_check_tgt_prog(tgt_prog);
+ if (err)
+ return err;
+ tr->extension_prog = link->link.prog;
+ return bpf_arch_text_poke(tr->func.addr, BPF_MOD_NOP,
+ BPF_MOD_JUMP, NULL,
+ link->link.prog->bpf_func);
}
+ err = bpf_trampoline_add_prog(tr, link, cnt);
+ if (err)
+ return err;
+ err = bpf_trampoline_update(tr, true /* lock_direct_mutex */, ops, data);
+ if (err)
+ bpf_trampoline_remove_prog(tr, link);
return err;
}
@@ -927,16 +949,8 @@ static int __bpf_trampoline_unlink_prog(struct bpf_tramp_link *link,
guard(mutex)(&tgt_prog->aux->ext_mutex);
tgt_prog->aux->is_extended = false;
return err;
- } else if (kind == BPF_TRAMP_FSESSION) {
- struct bpf_fsession_link *fslink =
- container_of(link, struct bpf_fsession_link, link.link);
-
- hlist_del_init(&fslink->fexit.tramp_hlist);
- tr->progs_cnt[BPF_TRAMP_FEXIT]--;
- kind = BPF_TRAMP_FENTRY;
}
- hlist_del_init(&link->tramp_hlist);
- tr->progs_cnt[kind]--;
+ bpf_trampoline_remove_prog(tr, link);
return bpf_trampoline_update(tr, true /* lock_direct_mutex */, ops, data);
}
--
2.53.0
next prev parent reply other threads:[~2026-04-17 19:26 UTC|newest]
Thread overview: 45+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-04-17 19:24 [PATCHv5 bpf-next 00/28] bpf: tracing_multi link Jiri Olsa
2026-04-17 19:24 ` [PATCHv5 bpf-next 01/28] ftrace: Add ftrace_hash_count function Jiri Olsa
2026-04-18 6:10 ` bot+bpf-ci
2026-04-17 19:24 ` [PATCHv5 bpf-next 02/28] ftrace: Add ftrace_hash_remove function Jiri Olsa
2026-04-18 6:10 ` bot+bpf-ci
2026-04-17 19:24 ` [PATCHv5 bpf-next 03/28] ftrace: Add add_ftrace_hash_entry function Jiri Olsa
2026-04-17 19:24 ` [PATCHv5 bpf-next 04/28] bpf: Use mutex lock pool for bpf trampolines Jiri Olsa
2026-04-17 20:10 ` bot+bpf-ci
2026-04-18 6:49 ` bot+bpf-ci
2026-04-17 19:24 ` [PATCHv5 bpf-next 05/28] bpf: Add struct bpf_trampoline_ops object Jiri Olsa
2026-04-17 19:24 ` [PATCHv5 bpf-next 06/28] bpf: Move trampoline image setup into bpf_trampoline_ops callbacks Jiri Olsa
2026-04-17 20:10 ` bot+bpf-ci
2026-04-18 6:10 ` bot+bpf-ci
2026-04-17 19:24 ` Jiri Olsa [this message]
2026-04-17 19:24 ` [PATCHv5 bpf-next 08/28] bpf: Add struct bpf_tramp_node object Jiri Olsa
2026-04-17 20:22 ` bot+bpf-ci
2026-04-18 6:10 ` bot+bpf-ci
2026-04-17 19:24 ` [PATCHv5 bpf-next 09/28] bpf: Factor fsession link to use struct bpf_tramp_node Jiri Olsa
2026-04-17 19:24 ` [PATCHv5 bpf-next 10/28] bpf: Add multi tracing attach types Jiri Olsa
2026-04-17 20:22 ` bot+bpf-ci
2026-04-18 6:49 ` bot+bpf-ci
2026-04-17 19:24 ` [PATCHv5 bpf-next 11/28] bpf: Move sleepable verification code to btf_id_allow_sleepable Jiri Olsa
2026-04-17 19:24 ` [PATCHv5 bpf-next 12/28] bpf: Add bpf_trampoline_multi_attach/detach functions Jiri Olsa
2026-04-17 20:22 ` bot+bpf-ci
2026-04-18 6:10 ` bot+bpf-ci
2026-04-17 19:24 ` [PATCHv5 bpf-next 13/28] bpf: Add support for tracing multi link Jiri Olsa
2026-04-17 19:24 ` [PATCHv5 bpf-next 14/28] bpf: Add support for tracing_multi link cookies Jiri Olsa
2026-04-17 19:24 ` [PATCHv5 bpf-next 15/28] bpf: Add support for tracing_multi link session Jiri Olsa
2026-04-17 19:24 ` [PATCHv5 bpf-next 16/28] bpf: Add support for tracing_multi link fdinfo Jiri Olsa
2026-04-17 19:24 ` [PATCHv5 bpf-next 17/28] libbpf: Add bpf_object_cleanup_btf function Jiri Olsa
2026-04-17 19:24 ` [PATCHv5 bpf-next 18/28] libbpf: Add bpf_link_create support for tracing_multi link Jiri Olsa
2026-04-17 19:24 ` [PATCHv5 bpf-next 19/28] libbpf: Add btf_type_is_traceable_func function Jiri Olsa
2026-04-18 5:59 ` bot+bpf-ci
2026-04-17 19:24 ` [PATCHv5 bpf-next 20/28] libbpf: Add support to create tracing multi link Jiri Olsa
2026-04-18 6:10 ` bot+bpf-ci
2026-04-17 19:24 ` [PATCHv5 bpf-next 21/28] selftests/bpf: Add tracing multi skel/pattern/ids attach tests Jiri Olsa
2026-04-17 20:10 ` bot+bpf-ci
2026-04-18 6:10 ` bot+bpf-ci
2026-04-17 19:24 ` [PATCHv5 bpf-next 22/28] selftests/bpf: Add tracing multi skel/pattern/ids module " Jiri Olsa
2026-04-17 19:24 ` [PATCHv5 bpf-next 23/28] selftests/bpf: Add tracing multi intersect tests Jiri Olsa
2026-04-17 19:24 ` [PATCHv5 bpf-next 24/28] selftests/bpf: Add tracing multi cookies test Jiri Olsa
2026-04-17 19:24 ` [PATCHv5 bpf-next 25/28] selftests/bpf: Add tracing multi session test Jiri Olsa
2026-04-17 19:25 ` [PATCHv5 bpf-next 26/28] selftests/bpf: Add tracing multi attach fails test Jiri Olsa
2026-04-17 19:25 ` [PATCHv5 bpf-next 27/28] selftests/bpf: Add tracing multi attach benchmark test Jiri Olsa
2026-04-17 19:25 ` [PATCHv5 bpf-next 28/28] selftests/bpf: Add tracing multi attach rollback tests Jiri Olsa
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