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: [PATCHv4 bpf-next 04/25] bpf: Add struct bpf_trampoline_ops object
Date: Tue, 24 Mar 2026 09:18:25 +0100 [thread overview]
Message-ID: <20260324081846.2334094-5-jolsa@kernel.org> (raw)
In-Reply-To: <20260324081846.2334094-1-jolsa@kernel.org>
In following changes we will need to override ftrace direct attachment
behaviour. In order to do that we are adding struct bpf_trampoline_ops
object that defines callbacks for ftrace direct attachment:
register_fentry
unregister_fentry
modify_fentry
The new struct bpf_trampoline_ops object is passed as an argument to
__bpf_trampoline_link/unlink_prog functions.
At the moment the default trampoline_ops is set to the current ftrace
direct attachment functions, so there's no functional change for the
current code.
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
---
kernel/bpf/trampoline.c | 59 ++++++++++++++++++++++++++++-------------
1 file changed, 41 insertions(+), 18 deletions(-)
diff --git a/kernel/bpf/trampoline.c b/kernel/bpf/trampoline.c
index eb4ea78ff77f..a76e093c9092 100644
--- a/kernel/bpf/trampoline.c
+++ b/kernel/bpf/trampoline.c
@@ -58,8 +58,18 @@ static void trampoline_unlock(struct bpf_trampoline *tr)
mutex_unlock(select_trampoline_lock(tr));
}
+struct bpf_trampoline_ops {
+ int (*register_fentry)(struct bpf_trampoline *tr, void *new_addr, void *data);
+ int (*unregister_fentry)(struct bpf_trampoline *tr, u32 orig_flags, void *old_addr,
+ void *data);
+ int (*modify_fentry)(struct bpf_trampoline *tr, u32 orig_flags, void *old_addr,
+ void *new_addr, bool lock_direct_mutex, void *data);
+};
+
#ifdef CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS
-static int bpf_trampoline_update(struct bpf_trampoline *tr, bool lock_direct_mutex);
+static int bpf_trampoline_update(struct bpf_trampoline *tr, bool lock_direct_mutex,
+ struct bpf_trampoline_ops *ops, void *data);
+static struct bpf_trampoline_ops trampoline_ops;
#ifdef CONFIG_HAVE_SINGLE_FTRACE_DIRECT_OPS
static struct bpf_trampoline *direct_ops_ip_lookup(struct ftrace_ops *ops, unsigned long ip)
@@ -144,13 +154,15 @@ static int bpf_tramp_ftrace_ops_func(struct ftrace_ops *ops, unsigned long ip,
if ((tr->flags & BPF_TRAMP_F_CALL_ORIG) &&
!(tr->flags & BPF_TRAMP_F_ORIG_STACK))
- ret = bpf_trampoline_update(tr, false /* lock_direct_mutex */);
+ ret = bpf_trampoline_update(tr, false /* lock_direct_mutex */,
+ &trampoline_ops, NULL);
break;
case FTRACE_OPS_CMD_DISABLE_SHARE_IPMODIFY_PEER:
tr->flags &= ~BPF_TRAMP_F_SHARE_IPMODIFY;
if (tr->flags & BPF_TRAMP_F_ORIG_STACK)
- ret = bpf_trampoline_update(tr, false /* lock_direct_mutex */);
+ ret = bpf_trampoline_update(tr, false /* lock_direct_mutex */,
+ &trampoline_ops, NULL);
break;
default:
ret = -EINVAL;
@@ -414,7 +426,7 @@ static int bpf_trampoline_update_fentry(struct bpf_trampoline *tr, u32 orig_flag
}
static int unregister_fentry(struct bpf_trampoline *tr, u32 orig_flags,
- void *old_addr)
+ void *old_addr, void *data)
{
int ret;
@@ -428,7 +440,7 @@ static int unregister_fentry(struct bpf_trampoline *tr, u32 orig_flags,
static int modify_fentry(struct bpf_trampoline *tr, u32 orig_flags,
void *old_addr, void *new_addr,
- bool lock_direct_mutex)
+ bool lock_direct_mutex, void *data __maybe_unused)
{
int ret;
@@ -442,7 +454,7 @@ static int modify_fentry(struct bpf_trampoline *tr, u32 orig_flags,
}
/* first time registering */
-static int register_fentry(struct bpf_trampoline *tr, void *new_addr)
+static int register_fentry(struct bpf_trampoline *tr, void *new_addr, void *data __maybe_unused)
{
void *ip = tr->func.addr;
unsigned long faddr;
@@ -464,6 +476,12 @@ static int register_fentry(struct bpf_trampoline *tr, void *new_addr)
return ret;
}
+static struct bpf_trampoline_ops trampoline_ops = {
+ .register_fentry = register_fentry,
+ .unregister_fentry = unregister_fentry,
+ .modify_fentry = modify_fentry,
+};
+
static struct bpf_tramp_links *
bpf_trampoline_get_progs(const struct bpf_trampoline *tr, int *total, bool *ip_arg)
{
@@ -631,7 +649,8 @@ static struct bpf_tramp_image *bpf_tramp_image_alloc(u64 key, int size)
return ERR_PTR(err);
}
-static int bpf_trampoline_update(struct bpf_trampoline *tr, bool lock_direct_mutex)
+static int bpf_trampoline_update(struct bpf_trampoline *tr, bool lock_direct_mutex,
+ struct bpf_trampoline_ops *ops, void *data)
{
struct bpf_tramp_image *im;
struct bpf_tramp_links *tlinks;
@@ -644,7 +663,7 @@ static int bpf_trampoline_update(struct bpf_trampoline *tr, bool lock_direct_mut
return PTR_ERR(tlinks);
if (total == 0) {
- err = unregister_fentry(tr, orig_flags, tr->cur_image->image);
+ err = ops->unregister_fentry(tr, orig_flags, tr->cur_image->image, data);
bpf_tramp_image_put(tr->cur_image);
tr->cur_image = NULL;
goto out;
@@ -715,11 +734,11 @@ static int bpf_trampoline_update(struct bpf_trampoline *tr, bool lock_direct_mut
WARN_ON(tr->cur_image && total == 0);
if (tr->cur_image)
/* progs already running at this address */
- err = modify_fentry(tr, orig_flags, tr->cur_image->image,
- im->image, lock_direct_mutex);
+ err = ops->modify_fentry(tr, orig_flags, tr->cur_image->image,
+ im->image, lock_direct_mutex, data);
else
/* first time registering */
- err = register_fentry(tr, im->image);
+ err = ops->register_fentry(tr, im->image, data);
#ifdef CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS
if (err == -EAGAIN) {
@@ -793,7 +812,9 @@ static int bpf_freplace_check_tgt_prog(struct bpf_prog *tgt_prog)
static int __bpf_trampoline_link_prog(struct bpf_tramp_link *link,
struct bpf_trampoline *tr,
- struct bpf_prog *tgt_prog)
+ struct bpf_prog *tgt_prog,
+ struct bpf_trampoline_ops *ops,
+ void *data)
{
struct bpf_fsession_link *fslink = NULL;
enum bpf_tramp_prog_type kind;
@@ -851,7 +872,7 @@ 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 */);
+ err = bpf_trampoline_update(tr, true /* lock_direct_mutex */, ops, data);
if (err) {
hlist_del_init(&link->tramp_hlist);
if (kind == BPF_TRAMP_FSESSION) {
@@ -872,14 +893,16 @@ int bpf_trampoline_link_prog(struct bpf_tramp_link *link,
int err;
trampoline_lock(tr);
- err = __bpf_trampoline_link_prog(link, tr, tgt_prog);
+ err = __bpf_trampoline_link_prog(link, tr, tgt_prog, &trampoline_ops, NULL);
trampoline_unlock(tr);
return err;
}
static int __bpf_trampoline_unlink_prog(struct bpf_tramp_link *link,
struct bpf_trampoline *tr,
- struct bpf_prog *tgt_prog)
+ struct bpf_prog *tgt_prog,
+ struct bpf_trampoline_ops *ops,
+ void *data)
{
enum bpf_tramp_prog_type kind;
int err;
@@ -904,7 +927,7 @@ static int __bpf_trampoline_unlink_prog(struct bpf_tramp_link *link,
}
hlist_del_init(&link->tramp_hlist);
tr->progs_cnt[kind]--;
- return bpf_trampoline_update(tr, true /* lock_direct_mutex */);
+ return bpf_trampoline_update(tr, true /* lock_direct_mutex */, ops, data);
}
/* bpf_trampoline_unlink_prog() should never fail. */
@@ -915,7 +938,7 @@ int bpf_trampoline_unlink_prog(struct bpf_tramp_link *link,
int err;
trampoline_lock(tr);
- err = __bpf_trampoline_unlink_prog(link, tr, tgt_prog);
+ err = __bpf_trampoline_unlink_prog(link, tr, tgt_prog, &trampoline_ops, NULL);
trampoline_unlock(tr);
return err;
}
@@ -1044,7 +1067,7 @@ int bpf_trampoline_link_cgroup_shim(struct bpf_prog *prog,
goto err;
}
- err = __bpf_trampoline_link_prog(&shim_link->link, tr, NULL);
+ err = __bpf_trampoline_link_prog(&shim_link->link, tr, NULL, &trampoline_ops, NULL);
if (err)
goto err;
--
2.53.0
next prev parent reply other threads:[~2026-03-24 8:19 UTC|newest]
Thread overview: 41+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-03-24 8:18 [PATCHv4 bpf-next 00/25] bpf: tracing_multi link Jiri Olsa
2026-03-24 8:18 ` [PATCHv4 bpf-next 01/25] ftrace: Add ftrace_hash_count function Jiri Olsa
2026-03-24 8:18 ` [PATCHv4 bpf-next 02/25] ftrace: Make ftrace_hash_clear global Jiri Olsa
2026-03-24 8:18 ` [PATCHv4 bpf-next 03/25] bpf: Use mutex lock pool for bpf trampolines Jiri Olsa
2026-03-24 8:18 ` Jiri Olsa [this message]
2026-03-24 8:18 ` [PATCHv4 bpf-next 05/25] bpf: Add struct bpf_tramp_node object Jiri Olsa
2026-03-24 8:18 ` [PATCHv4 bpf-next 06/25] bpf: Factor fsession link to use struct bpf_tramp_node Jiri Olsa
2026-03-24 8:18 ` [PATCHv4 bpf-next 07/25] bpf: Add multi tracing attach types Jiri Olsa
2026-03-24 8:18 ` [PATCHv4 bpf-next 08/25] bpf: Move sleepable verification code to btf_id_allow_sleepable Jiri Olsa
2026-03-24 8:18 ` [PATCHv4 bpf-next 09/25] bpf: Add bpf_trampoline_multi_attach/detach functions Jiri Olsa
2026-03-24 8:58 ` bot+bpf-ci
2026-03-24 14:29 ` Jiri Olsa
2026-03-27 4:18 ` kernel test robot
2026-03-24 8:18 ` [PATCHv4 bpf-next 10/25] bpf: Add support for tracing multi link Jiri Olsa
2026-03-24 8:18 ` [PATCHv4 bpf-next 11/25] bpf: Add support for tracing_multi link cookies Jiri Olsa
2026-03-24 8:18 ` [PATCHv4 bpf-next 12/25] bpf: Add support for tracing_multi link session Jiri Olsa
2026-03-24 8:18 ` [PATCHv4 bpf-next 13/25] bpf: Add support for tracing_multi link fdinfo Jiri Olsa
2026-03-25 6:43 ` Leon Hwang
2026-03-25 21:49 ` Jiri Olsa
2026-03-24 8:18 ` [PATCHv4 bpf-next 14/25] libbpf: Add bpf_object_cleanup_btf function Jiri Olsa
2026-03-24 8:18 ` [PATCHv4 bpf-next 15/25] libbpf: Add bpf_link_create support for tracing_multi link Jiri Olsa
2026-03-24 8:18 ` [PATCHv4 bpf-next 16/25] libbpf: Add btf_type_is_traceable_func function Jiri Olsa
2026-03-24 8:58 ` bot+bpf-ci
2026-03-24 14:29 ` Jiri Olsa
2026-03-24 8:18 ` [PATCHv4 bpf-next 17/25] libbpf: Add support to create tracing multi link Jiri Olsa
2026-03-24 8:18 ` [PATCHv4 bpf-next 18/25] selftests/bpf: Add tracing multi skel/pattern/ids attach tests Jiri Olsa
2026-03-24 8:18 ` [PATCHv4 bpf-next 19/25] selftests/bpf: Add tracing multi skel/pattern/ids module " Jiri Olsa
2026-03-24 8:18 ` [PATCHv4 bpf-next 20/25] selftests/bpf: Add tracing multi intersect tests Jiri Olsa
2026-03-24 8:18 ` [PATCHv4 bpf-next 21/25] selftests/bpf: Add tracing multi cookies test Jiri Olsa
2026-03-24 8:18 ` [PATCHv4 bpf-next 22/25] selftests/bpf: Add tracing multi session test Jiri Olsa
2026-03-24 8:18 ` [PATCHv4 bpf-next 23/25] selftests/bpf: Add tracing multi attach fails test Jiri Olsa
2026-03-24 8:18 ` [PATCHv4 bpf-next 24/25] selftests/bpf: Add tracing multi attach benchmark test Jiri Olsa
2026-03-25 6:45 ` Leon Hwang
2026-03-25 15:11 ` Alexei Starovoitov
2026-03-25 21:48 ` Jiri Olsa
2026-03-25 21:48 ` Jiri Olsa
2026-03-24 8:18 ` [PATCHv4 bpf-next 25/25] selftests/bpf: Add tracing multi attach rollback tests Jiri Olsa
2026-03-25 6:45 ` Leon Hwang
2026-03-25 21:49 ` Jiri Olsa
2026-03-25 6:42 ` [PATCHv4 bpf-next 00/25] bpf: tracing_multi link Leon Hwang
2026-03-25 14:58 ` Leon Hwang
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