From: Menglong Dong <menglong8.dong@gmail.com>
To: alexei.starovoitov@gmail.com, rostedt@goodmis.org, jolsa@kernel.org
Cc: bpf@vger.kernel.org, Menglong Dong <dongml2@chinatelecom.cn>,
linux-kernel@vger.kernel.org
Subject: [PATCH bpf-next 19/25] libbpf: support tracing_multi
Date: Wed, 28 May 2025 11:47:06 +0800 [thread overview]
Message-ID: <20250528034712.138701-20-dongml2@chinatelecom.cn> (raw)
In-Reply-To: <20250528034712.138701-1-dongml2@chinatelecom.cn>
Add supporting for the attach types of:
BPF_TRACE_FENTRY_MULTI
BPF_TRACE_FEXIT_MULTI
BPF_MODIFY_RETURN_MULTI
Signed-off-by: Menglong Dong <dongml2@chinatelecom.cn>
---
tools/bpf/bpftool/common.c | 3 +
tools/lib/bpf/bpf.c | 10 +++
tools/lib/bpf/bpf.h | 6 ++
tools/lib/bpf/libbpf.c | 168 ++++++++++++++++++++++++++++++++++++-
tools/lib/bpf/libbpf.h | 19 +++++
tools/lib/bpf/libbpf.map | 1 +
6 files changed, 204 insertions(+), 3 deletions(-)
diff --git a/tools/bpf/bpftool/common.c b/tools/bpf/bpftool/common.c
index ecfa790adc13..8e681fe3dd6b 100644
--- a/tools/bpf/bpftool/common.c
+++ b/tools/bpf/bpftool/common.c
@@ -1162,6 +1162,9 @@ const char *bpf_attach_type_input_str(enum bpf_attach_type t)
case BPF_TRACE_FENTRY: return "fentry";
case BPF_TRACE_FEXIT: return "fexit";
case BPF_MODIFY_RETURN: return "mod_ret";
+ case BPF_TRACE_FENTRY_MULTI: return "fentry_multi";
+ case BPF_TRACE_FEXIT_MULTI: return "fexit_multi";
+ case BPF_MODIFY_RETURN_MULTI: return "mod_ret_multi";
case BPF_SK_REUSEPORT_SELECT: return "sk_skb_reuseport_select";
case BPF_SK_REUSEPORT_SELECT_OR_MIGRATE: return "sk_skb_reuseport_select_or_migrate";
default: return libbpf_bpf_attach_type_str(t);
diff --git a/tools/lib/bpf/bpf.c b/tools/lib/bpf/bpf.c
index a9c3e33d0f8a..75a917de1a3c 100644
--- a/tools/lib/bpf/bpf.c
+++ b/tools/lib/bpf/bpf.c
@@ -797,6 +797,16 @@ int bpf_link_create(int prog_fd, int target_fd,
if (!OPTS_ZEROED(opts, tracing))
return libbpf_err(-EINVAL);
break;
+ case BPF_TRACE_FENTRY_MULTI:
+ case BPF_TRACE_FEXIT_MULTI:
+ case BPF_MODIFY_RETURN_MULTI:
+ attr.link_create.tracing_multi.btf_ids = ptr_to_u64(OPTS_GET(opts, tracing_multi.btf_ids, 0));
+ attr.link_create.tracing_multi.tgt_fds = ptr_to_u64(OPTS_GET(opts, tracing_multi.tgt_fds, 0));
+ attr.link_create.tracing_multi.cookies = ptr_to_u64(OPTS_GET(opts, tracing_multi.cookies, 0));
+ attr.link_create.tracing_multi.cnt = OPTS_GET(opts, tracing_multi.cnt, 0);
+ if (!OPTS_ZEROED(opts, tracing_multi))
+ return libbpf_err(-EINVAL);
+ break;
case BPF_NETFILTER:
attr.link_create.netfilter.pf = OPTS_GET(opts, netfilter.pf, 0);
attr.link_create.netfilter.hooknum = OPTS_GET(opts, netfilter.hooknum, 0);
diff --git a/tools/lib/bpf/bpf.h b/tools/lib/bpf/bpf.h
index 777627d33d25..c279b3bc80be 100644
--- a/tools/lib/bpf/bpf.h
+++ b/tools/lib/bpf/bpf.h
@@ -422,6 +422,12 @@ struct bpf_link_create_opts {
struct {
__u64 cookie;
} tracing;
+ struct {
+ __u32 cnt;
+ const __u32 *btf_ids;
+ const __u32 *tgt_fds;
+ const __u64 *cookies;
+ } tracing_multi;
struct {
__u32 pf;
__u32 hooknum;
diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index cfe81e1640d8..0c4ed5d237e5 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -136,6 +136,9 @@ 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",
+ [BPF_MODIFY_RETURN_MULTI] = "modify_return_multi",
};
static const char * const link_type_name[] = {
@@ -410,6 +413,8 @@ enum sec_def_flags {
SEC_XDP_FRAGS = 16,
/* Setup proper attach type for usdt probes. */
SEC_USDT = 32,
+ /* attachment target is multi-link */
+ SEC_ATTACH_BTF_MULTI = 64,
};
struct bpf_sec_def {
@@ -7417,9 +7422,9 @@ static int libbpf_prepare_prog_load(struct bpf_program *prog,
opts->expected_attach_type = BPF_TRACE_UPROBE_MULTI;
}
- if ((def & SEC_ATTACH_BTF) && !prog->attach_btf_id) {
+ if ((def & (SEC_ATTACH_BTF | SEC_ATTACH_BTF_MULTI)) && !prog->attach_btf_id) {
int btf_obj_fd = 0, btf_type_id = 0, err;
- const char *attach_name;
+ const char *attach_name, *name_end;
attach_name = strchr(prog->sec_name, '/');
if (!attach_name) {
@@ -7438,7 +7443,27 @@ static int libbpf_prepare_prog_load(struct bpf_program *prog,
}
attach_name++; /* skip over / */
- err = libbpf_find_attach_btf_id(prog, attach_name, &btf_obj_fd, &btf_type_id);
+ name_end = strchr(attach_name, ',');
+ /* for multi-link tracing, use the first target symbol during
+ * loading.
+ */
+ if ((def & SEC_ATTACH_BTF_MULTI) && name_end) {
+ int len = name_end - attach_name + 1;
+ char *first_tgt;
+
+ first_tgt = malloc(len);
+ if (!first_tgt)
+ return -ENOMEM;
+ libbpf_strlcpy(first_tgt, attach_name, len);
+ first_tgt[len - 1] = '\0';
+ err = libbpf_find_attach_btf_id(prog, first_tgt, &btf_obj_fd,
+ &btf_type_id);
+ free(first_tgt);
+ } else {
+ err = libbpf_find_attach_btf_id(prog, attach_name, &btf_obj_fd,
+ &btf_type_id);
+ }
+
if (err)
return err;
@@ -9507,6 +9532,7 @@ static int attach_kprobe_session(const struct bpf_program *prog, long cookie, st
static int attach_uprobe_multi(const struct bpf_program *prog, long cookie, struct bpf_link **link);
static int attach_lsm(const struct bpf_program *prog, long cookie, struct bpf_link **link);
static int attach_iter(const struct bpf_program *prog, long cookie, struct bpf_link **link);
+static int attach_trace_multi(const struct bpf_program *prog, long cookie, struct bpf_link **link);
static const struct bpf_sec_def section_defs[] = {
SEC_DEF("socket", SOCKET_FILTER, 0, SEC_NONE),
@@ -9553,6 +9579,13 @@ static const struct bpf_sec_def section_defs[] = {
SEC_DEF("fentry.s+", TRACING, BPF_TRACE_FENTRY, SEC_ATTACH_BTF | SEC_SLEEPABLE, attach_trace),
SEC_DEF("fmod_ret.s+", TRACING, BPF_MODIFY_RETURN, SEC_ATTACH_BTF | SEC_SLEEPABLE, attach_trace),
SEC_DEF("fexit.s+", TRACING, BPF_TRACE_FEXIT, SEC_ATTACH_BTF | SEC_SLEEPABLE, attach_trace),
+ SEC_DEF("tp_btf+", TRACING, BPF_TRACE_RAW_TP, SEC_ATTACH_BTF, attach_trace),
+ SEC_DEF("fentry.multi+", TRACING, BPF_TRACE_FENTRY_MULTI, SEC_ATTACH_BTF_MULTI, attach_trace_multi),
+ SEC_DEF("fmod_ret.multi+", TRACING, BPF_MODIFY_RETURN_MULTI, SEC_ATTACH_BTF_MULTI, attach_trace_multi),
+ SEC_DEF("fexit.multi+", TRACING, BPF_TRACE_FEXIT_MULTI, SEC_ATTACH_BTF_MULTI, attach_trace_multi),
+ SEC_DEF("fentry.multi.s+", TRACING, BPF_TRACE_FENTRY_MULTI, SEC_ATTACH_BTF_MULTI | SEC_SLEEPABLE, attach_trace_multi),
+ SEC_DEF("fmod_ret.multi.s+", TRACING, BPF_MODIFY_RETURN_MULTI, SEC_ATTACH_BTF_MULTI | SEC_SLEEPABLE, attach_trace_multi),
+ SEC_DEF("fexit.multi.s+", TRACING, BPF_TRACE_FEXIT_MULTI, SEC_ATTACH_BTF_MULTI | SEC_SLEEPABLE, attach_trace_multi),
SEC_DEF("freplace+", EXT, 0, SEC_ATTACH_BTF, attach_trace),
SEC_DEF("lsm+", LSM, BPF_LSM_MAC, SEC_ATTACH_BTF, attach_lsm),
SEC_DEF("lsm.s+", LSM, BPF_LSM_MAC, SEC_ATTACH_BTF | SEC_SLEEPABLE, attach_lsm),
@@ -12787,6 +12820,135 @@ static int attach_trace(const struct bpf_program *prog, long cookie, struct bpf_
return libbpf_get_error(*link);
}
+struct bpf_link *bpf_program__attach_trace_multi_opts(const struct bpf_program *prog,
+ const struct bpf_trace_multi_opts *opts)
+{
+ LIBBPF_OPTS(bpf_link_create_opts, link_opts);
+ __u32 *btf_ids = NULL, *tgt_fds = NULL;
+ struct bpf_link *link = NULL;
+ char errmsg[STRERR_BUFSIZE];
+ int prog_fd, pfd, cnt, err;
+
+ if (!OPTS_VALID(opts, bpf_trace_multi_opts))
+ return libbpf_err_ptr(-EINVAL);
+
+ prog_fd = bpf_program__fd(prog);
+ if (prog_fd < 0) {
+ pr_warn("prog '%s': can't attach before loaded\n", prog->name);
+ return libbpf_err_ptr(-EINVAL);
+ }
+
+ cnt = OPTS_GET(opts, cnt, 0);
+ if (opts->syms) {
+ int btf_obj_fd, btf_type_id, i;
+
+ if (opts->btf_ids || opts->tgt_fds) {
+ pr_warn("can set both opts->syms and opts->btf_ids\n");
+ return libbpf_err_ptr(-EINVAL);
+ }
+
+ btf_ids = malloc(sizeof(*btf_ids) * cnt);
+ tgt_fds = malloc(sizeof(*tgt_fds) * cnt);
+ if (!btf_ids || !tgt_fds) {
+ err = -ENOMEM;
+ goto err_free;
+ }
+ for (i = 0; i < cnt; i++) {
+ btf_obj_fd = btf_type_id = 0;
+
+ err = find_kernel_btf_id(prog->obj, opts->syms[i],
+ prog->expected_attach_type, &btf_obj_fd,
+ &btf_type_id);
+ if (err)
+ goto err_free;
+ btf_ids[i] = btf_type_id;
+ tgt_fds[i] = btf_obj_fd;
+ }
+ link_opts.tracing_multi.btf_ids = btf_ids;
+ link_opts.tracing_multi.tgt_fds = tgt_fds;
+ } else {
+ link_opts.tracing_multi.btf_ids = OPTS_GET(opts, btf_ids, 0);
+ link_opts.tracing_multi.tgt_fds = OPTS_GET(opts, tgt_fds, 0);
+ }
+
+ link = calloc(1, sizeof(*link));
+ if (!link) {
+ err = -ENOMEM;
+ goto err_free;
+ }
+ link->detach = &bpf_link__detach_fd;
+
+ link_opts.tracing_multi.cookies = OPTS_GET(opts, cookies, 0);
+ link_opts.tracing_multi.cnt = cnt;
+
+ pfd = bpf_link_create(prog_fd, 0, bpf_program__expected_attach_type(prog), &link_opts);
+ if (pfd < 0) {
+ err = -errno;
+ pr_warn("prog '%s': failed to attach: %s\n",
+ prog->name, libbpf_strerror_r(pfd, errmsg, sizeof(errmsg)));
+ goto err_free;
+ }
+ link->fd = pfd;
+
+ free(btf_ids);
+ free(tgt_fds);
+ return link;
+err_free:
+ free(btf_ids);
+ free(tgt_fds);
+ free(link);
+ return libbpf_err_ptr(err);
+}
+
+static int attach_trace_multi(const struct bpf_program *prog, long cookie, struct bpf_link **link)
+{
+ LIBBPF_OPTS(bpf_trace_multi_opts, opts);
+ int i, err, len, cnt = 1;
+ char **syms, *buf, *name;
+ const char *spec;
+
+ spec = strchr(prog->sec_name, '/');
+ if (!spec || !*(++spec))
+ return -EINVAL;
+
+ len = strlen(spec) + 1;
+ buf = malloc(len);
+ if (!buf)
+ return -ENOMEM;
+
+ libbpf_strlcpy(buf, spec, len);
+ for (i = 0; i < len; i++) {
+ if (buf[i] == ',')
+ cnt++;
+ }
+
+ syms = malloc(sizeof(*syms) * cnt);
+ if (!syms) {
+ err = -ENOMEM;
+ goto out_free;
+ }
+
+ opts.syms = (const char **)syms;
+ opts.cnt = cnt;
+ name = buf;
+ err = -EINVAL;
+ while (name) {
+ if (*name == '\0')
+ goto out_free;
+ *(syms++) = name;
+ name = strchr(name, ',');
+ if (name)
+ *(name++) = '\0';
+ }
+
+ *link = bpf_program__attach_trace_multi_opts(prog, &opts);
+ err = libbpf_get_error(*link);
+out_free:
+ free(buf);
+ free(opts.syms);
+ return err;
+}
+
static int attach_lsm(const struct bpf_program *prog, long cookie, struct bpf_link **link)
{
*link = bpf_program__attach_lsm(prog);
diff --git a/tools/lib/bpf/libbpf.h b/tools/lib/bpf/libbpf.h
index ded98e8cf327..d7f0db7ab586 100644
--- a/tools/lib/bpf/libbpf.h
+++ b/tools/lib/bpf/libbpf.h
@@ -833,6 +833,25 @@ bpf_program__attach_xdp(const struct bpf_program *prog, int ifindex);
LIBBPF_API struct bpf_link *
bpf_program__attach_freplace(const struct bpf_program *prog,
int target_fd, const char *attach_func_name);
+struct bpf_trace_multi_opts {
+ /* size of this struct, for forward/backward compatibility */
+ size_t sz;
+ /* array of function symbols to attach */
+ const char **syms;
+ /* array of the btf type id to attach */
+ __u32 *btf_ids;
+ /* array of the target fds */
+ __u32 *tgt_fds;
+ /* array of the cookies */
+ __u64 *cookies;
+ /* number of elements in syms/btf_ids/cookies arrays */
+ size_t cnt;
+};
+#define bpf_trace_multi_opts__last_field cnt
+
+LIBBPF_API struct bpf_link *
+bpf_program__attach_trace_multi_opts(const struct bpf_program *prog,
+ const struct bpf_trace_multi_opts *opts);
struct bpf_netfilter_opts {
/* size of this struct, for forward/backward compatibility */
diff --git a/tools/lib/bpf/libbpf.map b/tools/lib/bpf/libbpf.map
index 23df00ae0b73..fab014528b86 100644
--- a/tools/lib/bpf/libbpf.map
+++ b/tools/lib/bpf/libbpf.map
@@ -416,6 +416,7 @@ LIBBPF_1.4.0 {
btf__new_split;
btf_ext__raw_data;
bpf_object__free_btfs;
+ bpf_program__attach_trace_multi_opts;
} LIBBPF_1.3.0;
LIBBPF_1.5.0 {
--
2.39.5
next prev parent reply other threads:[~2025-05-28 3:50 UTC|newest]
Thread overview: 38+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-05-28 3:46 [PATCH bpf-next 00/25] bpf: tracing multi-link support Menglong Dong
2025-05-28 3:46 ` [PATCH bpf-next 01/25] add per-function metadata storage support Menglong Dong
2025-05-28 3:46 ` [PATCH bpf-next 02/25] x86: implement per-function metadata storage for x86 Menglong Dong
2025-05-28 3:46 ` [PATCH bpf-next 03/25] arm64: implement per-function metadata storage for arm64 Menglong Dong
2025-05-28 12:16 ` kernel test robot
2025-05-28 3:46 ` [PATCH bpf-next 04/25] bpf: make kfunc_md support global trampoline link Menglong Dong
2025-05-28 3:46 ` [PATCH bpf-next 05/25] x86,bpf: add bpf_global_caller for global trampoline Menglong Dong
2025-05-28 3:46 ` [PATCH bpf-next 06/25] ftrace: factor out ftrace_direct_update from register_ftrace_direct Menglong Dong
2025-05-28 3:46 ` [PATCH bpf-next 07/25] ftrace: add reset_ftrace_direct_ips Menglong Dong
2025-05-28 3:46 ` [PATCH bpf-next 08/25] bpf: introduce bpf_gtramp_link Menglong Dong
2025-05-28 3:46 ` [PATCH bpf-next 09/25] bpf: tracing: add support to record and check the accessed args Menglong Dong
2025-05-28 3:46 ` [PATCH bpf-next 10/25] bpf: refactor the modules_array to ptr_array Menglong Dong
2025-05-28 3:46 ` [PATCH bpf-next 11/25] bpf: verifier: add btf to the function args of bpf_check_attach_target Menglong Dong
2025-05-28 3:46 ` [PATCH bpf-next 12/25] bpf: verifier: move btf_id_deny to bpf_check_attach_target Menglong Dong
2025-05-28 3:47 ` [PATCH bpf-next 13/25] x86,bpf: factor out __arch_get_bpf_regs_nr Menglong Dong
2025-05-28 3:47 ` [PATCH bpf-next 14/25] bpf: tracing: add multi-link support Menglong Dong
2025-05-28 11:34 ` kernel test robot
2025-05-28 3:47 ` [PATCH bpf-next 15/25] ftrace: factor out __unregister_ftrace_direct Menglong Dong
2025-05-28 12:37 ` kernel test robot
2025-05-28 3:47 ` [PATCH bpf-next 16/25] ftrace: supporting replace direct ftrace_ops Menglong Dong
2025-05-28 3:47 ` [PATCH bpf-next 17/25] bpf: make trampoline compatible with global trampoline Menglong Dong
2025-05-28 3:47 ` [PATCH bpf-next 18/25] libbpf: don't free btf if tracing_multi progs existing Menglong Dong
2025-05-28 3:47 ` Menglong Dong [this message]
2025-05-28 3:47 ` [PATCH bpf-next 20/25] libbpf: add btf type hash lookup support Menglong Dong
2025-05-28 3:47 ` [PATCH bpf-next 21/25] libbpf: add skip_invalid and attach_tracing for tracing_multi Menglong Dong
2025-05-28 3:47 ` [PATCH bpf-next 22/25] selftests/bpf: use the glob_match() from libbpf in test_progs.c Menglong Dong
2025-05-28 3:47 ` [PATCH bpf-next 23/25] selftests/bpf: add get_ksyms and get_addrs to test_progs.c Menglong Dong
2025-05-28 3:47 ` [PATCH bpf-next 24/25] selftests/bpf: add testcases for multi-link of tracing Menglong Dong
2025-05-28 3:47 ` [PATCH bpf-next 25/25] selftests/bpf: add performance bench test for trace prog Menglong Dong
2025-05-28 13:51 ` [PATCH bpf-next 00/25] bpf: tracing multi-link support Steven Rostedt
2025-05-29 1:44 ` Menglong Dong
2025-06-11 3:32 ` Alexei Starovoitov
2025-06-11 12:58 ` Menglong Dong
2025-06-11 16:11 ` Alexei Starovoitov
2025-06-12 0:07 ` Menglong Dong
2025-06-12 0:58 ` Alexei Starovoitov
2025-06-12 3:18 ` Menglong Dong
2025-06-15 8:35 ` Menglong Dong
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