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: [PATCH bpf-next 06/17] bpf: Add multi tracing attach types
Date: Fri, 20 Feb 2026 11:06:38 +0100 [thread overview]
Message-ID: <20260220100649.628307-7-jolsa@kernel.org> (raw)
In-Reply-To: <20260220100649.628307-1-jolsa@kernel.org>
Adding new program attach types multi tracing attachment:
BPF_TRACE_FENTRY_MULTI
BPF_TRACE_FEXIT_MULTI
and their base support in verifier code.
Programs with such attach type will use specific link attachment
interface coming in following changes.
This was suggested by Andrii some (long) time ago and turned out
to be easier than having special program flag for that.
Bpf programs with such types have 'bpf_multi_func' function set
as their attach_btf_id.
Suggested-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
---
include/linux/bpf.h | 5 +++++
include/uapi/linux/bpf.h | 2 ++
kernel/bpf/btf.c | 2 ++
kernel/bpf/syscall.c | 35 ++++++++++++++++++++++++++++++----
kernel/bpf/trampoline.c | 5 ++++-
kernel/bpf/verifier.c | 9 +++++++++
net/bpf/test_run.c | 2 ++
tools/include/uapi/linux/bpf.h | 2 ++
tools/lib/bpf/libbpf.c | 2 ++
9 files changed, 59 insertions(+), 5 deletions(-)
diff --git a/include/linux/bpf.h b/include/linux/bpf.h
index d79951c0ab79..3d13ec5a66eb 100644
--- a/include/linux/bpf.h
+++ b/include/linux/bpf.h
@@ -2116,6 +2116,11 @@ void bpf_prog_disassoc_struct_ops(struct bpf_prog *prog);
void *bpf_prog_get_assoc_struct_ops(const struct bpf_prog_aux *aux);
u32 bpf_struct_ops_id(const void *kdata);
+static inline bool is_tracing_multi(enum bpf_attach_type type)
+{
+ return type == BPF_TRACE_FENTRY_MULTI || type == BPF_TRACE_FEXIT_MULTI;
+}
+
#ifdef CONFIG_NET
/* Define it here to avoid the use of forward declaration */
struct bpf_dummy_ops_state {
diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h
index c8d400b7680a..68600972a778 100644
--- a/include/uapi/linux/bpf.h
+++ b/include/uapi/linux/bpf.h
@@ -1154,6 +1154,8 @@ enum bpf_attach_type {
BPF_TRACE_KPROBE_SESSION,
BPF_TRACE_UPROBE_SESSION,
BPF_TRACE_FSESSION,
+ BPF_TRACE_FENTRY_MULTI,
+ BPF_TRACE_FEXIT_MULTI,
__MAX_BPF_ATTACH_TYPE
};
diff --git a/kernel/bpf/btf.c b/kernel/bpf/btf.c
index 7708958e3fb8..07d1e88e3524 100644
--- a/kernel/bpf/btf.c
+++ b/kernel/bpf/btf.c
@@ -6221,6 +6221,8 @@ static int btf_validate_prog_ctx_type(struct bpf_verifier_log *log, const struct
case BPF_TRACE_FEXIT:
case BPF_MODIFY_RETURN:
case BPF_TRACE_FSESSION:
+ case BPF_TRACE_FENTRY_MULTI:
+ case BPF_TRACE_FEXIT_MULTI:
/* allow u64* as ctx */
if (btf_is_int(t) && t->size == 8)
return 0;
diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
index 95a4bfbeab62..ff85a9fa080e 100644
--- a/kernel/bpf/syscall.c
+++ b/kernel/bpf/syscall.c
@@ -41,6 +41,7 @@
#include <linux/overflow.h>
#include <linux/cookie.h>
#include <linux/verification.h>
+#include <linux/btf_ids.h>
#include <net/netfilter/nf_bpf_link.h>
#include <net/netkit.h>
@@ -2653,7 +2654,8 @@ static int
bpf_prog_load_check_attach(enum bpf_prog_type prog_type,
enum bpf_attach_type expected_attach_type,
struct btf *attach_btf, u32 btf_id,
- struct bpf_prog *dst_prog)
+ struct bpf_prog *dst_prog,
+ bool multi_func)
{
if (btf_id) {
if (btf_id > BTF_MAX_TYPE)
@@ -2673,6 +2675,14 @@ bpf_prog_load_check_attach(enum bpf_prog_type prog_type,
}
}
+ if (multi_func) {
+ if (prog_type != BPF_PROG_TYPE_TRACING)
+ return -EINVAL;
+ if (!attach_btf || btf_id)
+ return -EINVAL;
+ return 0;
+ }
+
if (attach_btf && (!btf_id || dst_prog))
return -EINVAL;
@@ -2865,6 +2875,16 @@ static int bpf_prog_mark_insn_arrays_ready(struct bpf_prog *prog)
return 0;
}
+#define DEFINE_BPF_MULTI_FUNC(args...) \
+ extern int bpf_multi_func(args); \
+ int __init bpf_multi_func(args) { return 0; }
+
+DEFINE_BPF_MULTI_FUNC(unsigned long a1, unsigned long a2,
+ unsigned long a3, unsigned long a4,
+ unsigned long a5, unsigned long a6)
+
+BTF_ID_LIST_SINGLE(bpf_multi_func_btf_id, func, bpf_multi_func)
+
/* last field in 'union bpf_attr' used by this command */
#define BPF_PROG_LOAD_LAST_FIELD keyring_id
@@ -2877,6 +2897,7 @@ static int bpf_prog_load(union bpf_attr *attr, bpfptr_t uattr, u32 uattr_size)
bool bpf_cap;
int err;
char license[128];
+ bool multi_func;
if (CHECK_ATTR(BPF_PROG_LOAD))
return -EINVAL;
@@ -2943,6 +2964,8 @@ static int bpf_prog_load(union bpf_attr *attr, bpfptr_t uattr, u32 uattr_size)
if (is_perfmon_prog_type(type) && !bpf_token_capable(token, CAP_PERFMON))
goto put_token;
+ multi_func = is_tracing_multi(attr->expected_attach_type);
+
/* attach_prog_fd/attach_btf_obj_fd can specify fd of either bpf_prog
* or btf, we need to check which one it is
*/
@@ -2964,7 +2987,7 @@ static int bpf_prog_load(union bpf_attr *attr, bpfptr_t uattr, u32 uattr_size)
goto put_token;
}
}
- } else if (attr->attach_btf_id) {
+ } else if (attr->attach_btf_id || multi_func) {
/* fall back to vmlinux BTF, if BTF type ID is specified */
attach_btf = bpf_get_btf_vmlinux();
if (IS_ERR(attach_btf)) {
@@ -2980,7 +3003,7 @@ static int bpf_prog_load(union bpf_attr *attr, bpfptr_t uattr, u32 uattr_size)
if (bpf_prog_load_check_attach(type, attr->expected_attach_type,
attach_btf, attr->attach_btf_id,
- dst_prog)) {
+ dst_prog, multi_func)) {
if (dst_prog)
bpf_prog_put(dst_prog);
if (attach_btf)
@@ -3003,7 +3026,7 @@ static int bpf_prog_load(union bpf_attr *attr, bpfptr_t uattr, u32 uattr_size)
prog->expected_attach_type = attr->expected_attach_type;
prog->sleepable = !!(attr->prog_flags & BPF_F_SLEEPABLE);
prog->aux->attach_btf = attach_btf;
- prog->aux->attach_btf_id = attr->attach_btf_id;
+ prog->aux->attach_btf_id = multi_func ? bpf_multi_func_btf_id[0] : attr->attach_btf_id;
prog->aux->dst_prog = dst_prog;
prog->aux->dev_bound = !!attr->prog_ifindex;
prog->aux->xdp_has_frags = attr->prog_flags & BPF_F_XDP_HAS_FRAGS;
@@ -3588,6 +3611,8 @@ static int bpf_tracing_prog_attach(struct bpf_prog *prog,
if (prog->expected_attach_type != BPF_TRACE_FENTRY &&
prog->expected_attach_type != BPF_TRACE_FEXIT &&
prog->expected_attach_type != BPF_TRACE_FSESSION &&
+ prog->expected_attach_type != BPF_TRACE_FENTRY_MULTI &&
+ prog->expected_attach_type != BPF_TRACE_FEXIT_MULTI &&
prog->expected_attach_type != BPF_MODIFY_RETURN) {
err = -EINVAL;
goto out_put_prog;
@@ -4365,6 +4390,8 @@ attach_type_to_prog_type(enum bpf_attach_type attach_type)
case BPF_TRACE_FENTRY:
case BPF_TRACE_FEXIT:
case BPF_TRACE_FSESSION:
+ case BPF_TRACE_FENTRY_MULTI:
+ case BPF_TRACE_FEXIT_MULTI:
case BPF_MODIFY_RETURN:
return BPF_PROG_TYPE_TRACING;
case BPF_LSM_MAC:
diff --git a/kernel/bpf/trampoline.c b/kernel/bpf/trampoline.c
index 14fa7012738a..2d701bc6e1a5 100644
--- a/kernel/bpf/trampoline.c
+++ b/kernel/bpf/trampoline.c
@@ -189,7 +189,8 @@ bool bpf_prog_has_trampoline(const struct bpf_prog *prog)
switch (ptype) {
case BPF_PROG_TYPE_TRACING:
if (eatype == BPF_TRACE_FENTRY || eatype == BPF_TRACE_FEXIT ||
- eatype == BPF_MODIFY_RETURN || eatype == BPF_TRACE_FSESSION)
+ eatype == BPF_MODIFY_RETURN || eatype == BPF_TRACE_FSESSION ||
+ eatype == BPF_TRACE_FENTRY_MULTI || eatype == BPF_TRACE_FEXIT_MULTI)
return true;
return false;
case BPF_PROG_TYPE_LSM:
@@ -783,10 +784,12 @@ static enum bpf_tramp_prog_type bpf_attach_type_to_tramp(struct bpf_prog *prog)
{
switch (prog->expected_attach_type) {
case BPF_TRACE_FENTRY:
+ case BPF_TRACE_FENTRY_MULTI:
return BPF_TRAMP_FENTRY;
case BPF_MODIFY_RETURN:
return BPF_TRAMP_MODIFY_RETURN;
case BPF_TRACE_FEXIT:
+ case BPF_TRACE_FEXIT_MULTI:
return BPF_TRAMP_FEXIT;
case BPF_TRACE_FSESSION:
return BPF_TRAMP_FSESSION;
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index 2b93cd3f8625..9c9303103a9c 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -17911,6 +17911,8 @@ static int check_return_code(struct bpf_verifier_env *env, int regno, const char
case BPF_TRACE_FENTRY:
case BPF_TRACE_FEXIT:
case BPF_TRACE_FSESSION:
+ case BPF_TRACE_FENTRY_MULTI:
+ case BPF_TRACE_FEXIT_MULTI:
range = retval_range(0, 0);
break;
case BPF_TRACE_RAW_TP:
@@ -23961,6 +23963,7 @@ static int do_misc_fixups(struct bpf_verifier_env *env)
insn->imm == BPF_FUNC_get_func_ret) {
if (eatype == BPF_TRACE_FEXIT ||
eatype == BPF_TRACE_FSESSION ||
+ eatype == BPF_TRACE_FEXIT_MULTI ||
eatype == BPF_MODIFY_RETURN) {
/* Load nr_args from ctx - 8 */
insn_buf[0] = BPF_LDX_MEM(BPF_DW, BPF_REG_0, BPF_REG_1, -8);
@@ -25018,6 +25021,8 @@ int bpf_check_attach_target(struct bpf_verifier_log *log,
case BPF_TRACE_FENTRY:
case BPF_TRACE_FEXIT:
case BPF_TRACE_FSESSION:
+ case BPF_TRACE_FENTRY_MULTI:
+ case BPF_TRACE_FEXIT_MULTI:
if (prog->expected_attach_type == BPF_TRACE_FSESSION &&
!bpf_jit_supports_fsession()) {
bpf_log(log, "JIT does not support fsession\n");
@@ -25190,6 +25195,8 @@ static bool can_be_sleepable(struct bpf_prog *prog)
case BPF_MODIFY_RETURN:
case BPF_TRACE_ITER:
case BPF_TRACE_FSESSION:
+ case BPF_TRACE_FENTRY_MULTI:
+ case BPF_TRACE_FEXIT_MULTI:
return true;
default:
return false;
@@ -25259,6 +25266,8 @@ static int check_attach_btf_id(struct bpf_verifier_env *env)
return 0;
} else if (prog->expected_attach_type == BPF_TRACE_ITER) {
return bpf_iter_prog_supported(prog);
+ } else if (is_tracing_multi(prog->expected_attach_type)) {
+ return prog->type == BPF_PROG_TYPE_TRACING ? 0 : -EINVAL;
}
if (prog->type == BPF_PROG_TYPE_LSM) {
diff --git a/net/bpf/test_run.c b/net/bpf/test_run.c
index 178c4738e63b..3373450132f0 100644
--- a/net/bpf/test_run.c
+++ b/net/bpf/test_run.c
@@ -686,6 +686,8 @@ int bpf_prog_test_run_tracing(struct bpf_prog *prog,
case BPF_TRACE_FENTRY:
case BPF_TRACE_FEXIT:
case BPF_TRACE_FSESSION:
+ case BPF_TRACE_FENTRY_MULTI:
+ case BPF_TRACE_FEXIT_MULTI:
if (bpf_fentry_test1(1) != 2 ||
bpf_fentry_test2(2, 3) != 5 ||
bpf_fentry_test3(4, 5, 6) != 15 ||
diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h
index 5e38b4887de6..61f0fe5bc0aa 100644
--- a/tools/include/uapi/linux/bpf.h
+++ b/tools/include/uapi/linux/bpf.h
@@ -1154,6 +1154,8 @@ enum bpf_attach_type {
BPF_TRACE_KPROBE_SESSION,
BPF_TRACE_UPROBE_SESSION,
BPF_TRACE_FSESSION,
+ BPF_TRACE_FENTRY_MULTI,
+ BPF_TRACE_FEXIT_MULTI,
__MAX_BPF_ATTACH_TYPE
};
diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index 0be7017800fe..1e19c7b861ec 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -136,6 +136,8 @@ static const char * const attach_type_name[] = {
[BPF_NETKIT_PEER] = "netkit_peer",
[BPF_TRACE_KPROBE_SESSION] = "trace_kprobe_session",
[BPF_TRACE_UPROBE_SESSION] = "trace_uprobe_session",
+ [BPF_TRACE_FENTRY_MULTI] = "trace_fentry_multi",
+ [BPF_TRACE_FEXIT_MULTI] = "trace_fexit_multi",
};
static const char * const link_type_name[] = {
--
2.52.0
next prev parent reply other threads:[~2026-02-20 10:08 UTC|newest]
Thread overview: 38+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-02-20 10:06 [PATCH bpf-next 00/17] bpf: tracing_multi link Jiri Olsa
2026-02-20 10:06 ` [PATCH bpf-next 01/17] ftrace: Add ftrace_hash_count function Jiri Olsa
2026-02-20 10:06 ` [PATCH bpf-next 02/17] bpf: Use mutex lock pool for bpf trampolines Jiri Olsa
2026-02-20 10:57 ` bot+bpf-ci
2026-02-22 14:33 ` Jiri Olsa
2026-02-20 19:58 ` Alexei Starovoitov
2026-02-22 14:34 ` Jiri Olsa
2026-02-23 19:35 ` Alexei Starovoitov
2026-02-24 12:27 ` Jiri Olsa
2026-02-24 17:13 ` Alexei Starovoitov
2026-02-20 10:06 ` [PATCH bpf-next 03/17] bpf: Add struct bpf_trampoline_ops object Jiri Olsa
2026-02-20 10:06 ` [PATCH bpf-next 04/17] bpf: Add struct bpf_tramp_node object Jiri Olsa
2026-02-20 10:58 ` bot+bpf-ci
2026-02-22 14:34 ` Jiri Olsa
2026-02-20 19:52 ` kernel test robot
2026-02-20 21:05 ` kernel test robot
2026-02-21 3:00 ` kernel test robot
2026-02-20 10:06 ` [PATCH bpf-next 05/17] bpf: Factor fsession link to use struct bpf_tramp_node Jiri Olsa
2026-02-20 10:06 ` Jiri Olsa [this message]
2026-02-20 10:06 ` [PATCH bpf-next 07/17] bpf: Add bpf_trampoline_multi_attach/detach functions Jiri Olsa
2026-02-20 10:57 ` bot+bpf-ci
2026-02-22 14:34 ` Jiri Olsa
2026-02-20 10:06 ` [PATCH bpf-next 08/17] bpf: Add support for tracing multi link Jiri Olsa
2026-02-20 10:57 ` bot+bpf-ci
2026-02-22 14:35 ` Jiri Olsa
2026-02-20 10:06 ` [PATCH bpf-next 09/17] bpf: Add support for tracing_multi link cookies Jiri Olsa
2026-02-20 10:06 ` [PATCH bpf-next 10/17] bpf: Add support for tracing_multi link session Jiri Olsa
2026-02-20 10:57 ` bot+bpf-ci
2026-02-22 14:35 ` Jiri Olsa
2026-02-20 10:06 ` [PATCH bpf-next 11/17] libbpf: Add support to create tracing multi link Jiri Olsa
2026-02-20 10:57 ` bot+bpf-ci
2026-02-22 14:36 ` Jiri Olsa
2026-02-20 10:06 ` [PATCH bpf-next 12/17] selftests/bpf: Add tracing multi skel/pattern/ids attach tests Jiri Olsa
2026-02-20 10:06 ` [PATCH bpf-next 13/17] selftests/bpf: Add tracing multi intersect tests Jiri Olsa
2026-02-20 10:06 ` [PATCH bpf-next 14/17] selftests/bpf: Add tracing multi cookies test Jiri Olsa
2026-02-20 10:06 ` [PATCH bpf-next 15/17] selftests/bpf: Add tracing multi session test Jiri Olsa
2026-02-20 10:06 ` [PATCH bpf-next 16/17] selftests/bpf: Add tracing multi attach fails test Jiri Olsa
2026-02-20 10:06 ` [PATCH bpf-next 17/17] selftests/bpf: Add tracing multi attach benchmark test Jiri Olsa
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