Adding new interface function to attach programs with tracing
multi link:
bpf_program__attach_tracing_multi(const struct bpf_program *prog,
const char *pattern,
const struct bpf_tracing_multi_opts *opts);
The program is attach to functions specified by pattern or by
btf IDs specified in bpf_tracing_multi_opts object.
Adding support for new sections to attach programs with above
functions:
fentry.multi/pattern
fexit.multi/pattern
Signed-off-by: Jiri Olsa <[email protected]>
---
tools/lib/bpf/bpf.c | 7 ++++
tools/lib/bpf/bpf.h | 4 ++
tools/lib/bpf/libbpf.c | 87 ++++++++++++++++++++++++++++++++++++++++
tools/lib/bpf/libbpf.h | 14 +++++++
tools/lib/bpf/libbpf.map | 1 +
5 files changed, 113 insertions(+)
diff --git a/tools/lib/bpf/bpf.c b/tools/lib/bpf/bpf.c
index 5846de364209..cee1fc6bbfd6 100644
--- a/tools/lib/bpf/bpf.c
+++ b/tools/lib/bpf/bpf.c
@@ -790,6 +790,13 @@ int bpf_link_create(int prog_fd, int target_fd,
if (!OPTS_ZEROED(opts, uprobe_multi))
return libbpf_err(-EINVAL);
break;
+ case BPF_TRACE_FENTRY_MULTI:
+ case BPF_TRACE_FEXIT_MULTI:
+ attr.link_create.tracing_multi.btf_ids = (__u64) OPTS_GET(opts,
tracing_multi.btf_ids, 0);
+ attr.link_create.tracing_multi.btf_ids_cnt = OPTS_GET(opts,
tracing_multi.btf_ids_cnt, 0);
+ if (!OPTS_ZEROED(opts, tracing_multi))
+ return libbpf_err(-EINVAL);
+ break;
case BPF_TRACE_RAW_TP:
case BPF_TRACE_FENTRY:
case BPF_TRACE_FEXIT:
diff --git a/tools/lib/bpf/bpf.h b/tools/lib/bpf/bpf.h
index 2c8e88ddb674..005f884f9a0c 100644
--- a/tools/lib/bpf/bpf.h
+++ b/tools/lib/bpf/bpf.h
@@ -454,6 +454,10 @@ struct bpf_link_create_opts {
__u32 relative_id;
__u64 expected_revision;
} cgroup;
+ struct {
+ __u32 *btf_ids;
+ __u32 btf_ids_cnt;
+ } tracing_multi;
};
size_t :0;
};
diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index 0c8bf0b5cce4..a16243300083 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[] = {
@@ -154,6 +156,7 @@ static const char * const link_type_name[] = {
[BPF_LINK_TYPE_UPROBE_MULTI] = "uprobe_multi",
[BPF_LINK_TYPE_NETKIT] = "netkit",
[BPF_LINK_TYPE_SOCKMAP] = "sockmap",
+ [BPF_LINK_TYPE_TRACING_MULTI] = "tracing_multi",
};
static const char * const map_type_name[] = {
@@ -9814,6 +9817,7 @@ 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_tracing_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),
@@ -9862,6 +9866,8 @@ static const struct bpf_sec_def section_defs[] = {
SEC_DEF("fexit.s+", TRACING, BPF_TRACE_FEXIT,
SEC_ATTACH_BTF | SEC_SLEEPABLE, attach_trace),
SEC_DEF("fsession+", TRACING, BPF_TRACE_FSESSION,
SEC_ATTACH_BTF, attach_trace),
SEC_DEF("fsession.s+", TRACING, BPF_TRACE_FSESSION,
SEC_ATTACH_BTF | SEC_SLEEPABLE, attach_trace),
+ SEC_DEF("fentry.multi+", TRACING, BPF_TRACE_FENTRY_MULTI, 0,
attach_tracing_multi),
+ SEC_DEF("fexit.multi+", TRACING, BPF_TRACE_FEXIT_MULTI, 0,
attach_tracing_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),
@@ -12237,6 +12243,87 @@ static int attach_uprobe_multi(const struct
bpf_program *prog, long cookie, stru
return ret;
}
+struct bpf_link *
+bpf_program__attach_tracing_multi(const struct bpf_program *prog, const char
*pattern,
+ const struct bpf_tracing_multi_opts *opts)
+{
+ LIBBPF_OPTS(bpf_link_create_opts, lopts);
+ __u32 *btf_ids, cnt, *free_ids = NULL;
+ int prog_fd, link_fd, err;
+ struct bpf_link *link;
+
+ btf_ids = OPTS_GET(opts, btf_ids, false);
+ cnt = OPTS_GET(opts, cnt, false);
+
+ if (!pattern && !btf_ids && !cnt)
+ return libbpf_err_ptr(-EINVAL);
+ if (pattern && (btf_ids || cnt))
+ return libbpf_err_ptr(-EINVAL);
+
+ if (pattern) {
+ err = bpf_object__load_vmlinux_btf(prog->obj, true);
+ if (err)
+ return libbpf_err_ptr(err);
+
+ cnt = btf__find_by_glob_kind(prog->obj->btf_vmlinux,
BTF_KIND_FUNC,
+ pattern, NULL, &btf_ids);
+ if (cnt <= 0)
+ return libbpf_err_ptr(-EINVAL);
+ free_ids = btf_ids;
+ }
+
+ lopts.tracing_multi.btf_ids = btf_ids;
+ lopts.tracing_multi.btf_ids_cnt = cnt;
+
+ link = calloc(1, sizeof(*link));
+ if (!link)
+ return libbpf_err_ptr(-ENOMEM);
+ link->detach = &bpf_link__detach_fd;
+
+ prog_fd = bpf_program__fd(prog);
+ link_fd = bpf_link_create(prog_fd, 0, prog->expected_attach_type,
&lopts);
+ if (link_fd < 0) {
+ err = -errno;
+ pr_warn("prog '%s': failed to attach: %s\n", prog->name,
errstr(err));
+ goto error;
+ }
+ link->fd = link_fd;
+ free(free_ids);
+ return link;
+error:
+ free(link);
+ free(free_ids);
+ return libbpf_err_ptr(err);
+}
+
+static int attach_tracing_multi(const struct bpf_program *prog, long cookie,
struct bpf_link **link)
+{
+ const char *spec;
+ char *pattern;
+ bool is_fexit;
+ int n;
+
+ /* no auto-attach for SEC("fentry.multi") and SEC("fexit.multi") */
+ if (strcmp(prog->sec_name, "fentry.multi") == 0 ||
+ strcmp(prog->sec_name, "fexit.multi") == 0)
+ return 0;
+
+ is_fexit = str_has_pfx(prog->sec_name, "fexit.multi/");
+ if (is_fexit)
+ spec = prog->sec_name + sizeof("fexit.multi/") - 1;
+ else
+ spec = prog->sec_name + sizeof("fentry.multi/") - 1;
+
+ n = sscanf(spec, "%m[a-zA-Z0-9_.*?]", &pattern);
+ if (n < 1) {
+ pr_warn("tracing multi pattern is invalid: %s\n", pattern);
+ return -EINVAL;
+ }
+
+ *link = bpf_program__attach_tracing_multi(prog, pattern, NULL);
+ return libbpf_get_error(*link);
+}
+
static inline int add_uprobe_event_legacy(const char *probe_name, bool
retprobe,
const char *binary_path, size_t
offset)
{
diff --git a/tools/lib/bpf/libbpf.h b/tools/lib/bpf/libbpf.h
index dfc37a615578..fa74a88f6c4a 100644
--- a/tools/lib/bpf/libbpf.h
+++ b/tools/lib/bpf/libbpf.h
@@ -701,6 +701,20 @@ bpf_program__attach_ksyscall(const struct bpf_program
*prog,
const char *syscall_name,
const struct bpf_ksyscall_opts *opts);
+struct bpf_tracing_multi_opts {
+ /* size of this struct, for forward/backward compatibility */
+ size_t sz;
+ __u32 *btf_ids;
+ size_t cnt;
+ size_t :0;
+};
+
+#define bpf_tracing_multi_opts__last_field cnt
+
+LIBBPF_API struct bpf_link *
+bpf_program__attach_tracing_multi(const struct bpf_program *prog, const char
*pattern,
+ const struct bpf_tracing_multi_opts *opts);
+
struct bpf_uprobe_opts {
/* size of this struct, for forward/backward compatibility */
size_t sz;
diff --git a/tools/lib/bpf/libbpf.map b/tools/lib/bpf/libbpf.map
index d18fbcea7578..a3ffb21270e9 100644
--- a/tools/lib/bpf/libbpf.map
+++ b/tools/lib/bpf/libbpf.map
@@ -358,6 +358,7 @@ LIBBPF_1.0.0 {
bpf_program__attach_ksyscall;
bpf_program__autoattach;
bpf_program__set_autoattach;
+ bpf_program__attach_tracing_multi;
btf__add_enum64;
btf__add_enum64_value;
libbpf_bpf_attach_type_str;
--
2.52.0
