From: Alexei Starovoitov <ast@kernel.org>
To: <davem@davemloft.net>
Cc: <daniel@iogearbox.net>, <x86@kernel.org>,
<netdev@vger.kernel.org>, <bpf@vger.kernel.org>,
<kernel-team@fb.com>
Subject: [PATCH v3 bpf-next 05/18] libbpf: Add support to attach to fentry/fexit tracing progs
Date: Thu, 7 Nov 2019 22:40:26 -0800 [thread overview]
Message-ID: <20191108064039.2041889-6-ast@kernel.org> (raw)
In-Reply-To: <20191108064039.2041889-1-ast@kernel.org>
Teach libbpf to recognize tracing programs types and attach them to
fentry/fexit.
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
---
tools/include/uapi/linux/bpf.h | 2 +
tools/lib/bpf/libbpf.c | 99 +++++++++++++++++++++++++---------
tools/lib/bpf/libbpf.h | 4 ++
tools/lib/bpf/libbpf.map | 2 +
4 files changed, 82 insertions(+), 25 deletions(-)
diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h
index df6809a76404..69c200e6e696 100644
--- a/tools/include/uapi/linux/bpf.h
+++ b/tools/include/uapi/linux/bpf.h
@@ -201,6 +201,8 @@ enum bpf_attach_type {
BPF_CGROUP_GETSOCKOPT,
BPF_CGROUP_SETSOCKOPT,
BPF_TRACE_RAW_TP,
+ BPF_TRACE_FENTRY,
+ BPF_TRACE_FEXIT,
__MAX_BPF_ATTACH_TYPE
};
diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index fde6cb3e5d41..e9c9961bbb9f 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -3859,7 +3859,8 @@ bpf_object__load_progs(struct bpf_object *obj, int log_level)
return 0;
}
-static int libbpf_attach_btf_id_by_name(const char *name, __u32 *btf_id);
+static int libbpf_attach_btf_id_by_name(const char *name,
+ enum bpf_attach_type attach_type);
static struct bpf_object *
__bpf_object__open(const char *path, const void *obj_buf, size_t obj_buf_sz,
@@ -3913,7 +3914,6 @@ __bpf_object__open(const char *path, const void *obj_buf, size_t obj_buf_sz,
bpf_object__for_each_program(prog, obj) {
enum bpf_prog_type prog_type;
enum bpf_attach_type attach_type;
- __u32 btf_id;
err = libbpf_prog_type_by_name(prog->section_name, &prog_type,
&attach_type);
@@ -3926,10 +3926,11 @@ __bpf_object__open(const char *path, const void *obj_buf, size_t obj_buf_sz,
bpf_program__set_type(prog, prog_type);
bpf_program__set_expected_attach_type(prog, attach_type);
if (prog_type == BPF_PROG_TYPE_TRACING) {
- err = libbpf_attach_btf_id_by_name(prog->section_name, &btf_id);
- if (err)
+ err = libbpf_attach_btf_id_by_name(prog->section_name,
+ attach_type);
+ if (err <= 0)
goto out;
- prog->attach_btf_id = btf_id;
+ prog->attach_btf_id = err;
}
}
@@ -4928,6 +4929,10 @@ static const struct {
BPF_PROG_SEC("raw_tp/", BPF_PROG_TYPE_RAW_TRACEPOINT),
BPF_PROG_BTF("tp_btf/", BPF_PROG_TYPE_TRACING,
BPF_TRACE_RAW_TP),
+ BPF_PROG_BTF("fentry/", BPF_PROG_TYPE_TRACING,
+ BPF_TRACE_FENTRY),
+ BPF_PROG_BTF("fexit/", BPF_PROG_TYPE_TRACING,
+ BPF_TRACE_FEXIT),
BPF_PROG_SEC("xdp", BPF_PROG_TYPE_XDP),
BPF_PROG_SEC("perf_event", BPF_PROG_TYPE_PERF_EVENT),
BPF_PROG_SEC("lwt_in", BPF_PROG_TYPE_LWT_IN),
@@ -5045,43 +5050,56 @@ int libbpf_prog_type_by_name(const char *name, enum bpf_prog_type *prog_type,
}
#define BTF_PREFIX "btf_trace_"
-static int libbpf_attach_btf_id_by_name(const char *name, __u32 *btf_id)
+int libbpf_find_vmlinux_btf_id(const char *name,
+ enum bpf_attach_type attach_type)
{
struct btf *btf = bpf_core_find_kernel_btf();
- char raw_tp_btf_name[128] = BTF_PREFIX;
- char *dst = raw_tp_btf_name + sizeof(BTF_PREFIX) - 1;
- int ret, i, err = -EINVAL;
+ char raw_tp_btf[128] = BTF_PREFIX;
+ char *dst = raw_tp_btf + sizeof(BTF_PREFIX) - 1;
+ const char *btf_name;
+ int err = -EINVAL;
+ u32 kind;
if (IS_ERR(btf)) {
pr_warn("vmlinux BTF is not found\n");
return -EINVAL;
}
+ if (attach_type == BPF_TRACE_RAW_TP) {
+ /* prepend "btf_trace_" prefix per kernel convention */
+ strncat(dst, name, sizeof(raw_tp_btf) - sizeof(BTF_PREFIX));
+ btf_name = raw_tp_btf;
+ kind = BTF_KIND_TYPEDEF;
+ } else {
+ btf_name = name;
+ kind = BTF_KIND_FUNC;
+ }
+ err = btf__find_by_name_kind(btf, btf_name, kind);
+ btf__free(btf);
+ return err;
+}
+
+static int libbpf_attach_btf_id_by_name(const char *name,
+ enum bpf_attach_type attach_type)
+{
+ int i, err;
+
if (!name)
- goto out;
+ return -EINVAL;
for (i = 0; i < ARRAY_SIZE(section_names); i++) {
if (!section_names[i].is_attach_btf)
continue;
if (strncmp(name, section_names[i].sec, section_names[i].len))
continue;
- /* prepend "btf_trace_" prefix per kernel convention */
- strncat(dst, name + section_names[i].len,
- sizeof(raw_tp_btf_name) - sizeof(BTF_PREFIX));
- ret = btf__find_by_name(btf, raw_tp_btf_name);
- if (ret <= 0) {
- pr_warn("%s is not found in vmlinux BTF\n", dst);
- goto out;
- }
- *btf_id = ret;
- err = 0;
- goto out;
+ err = libbpf_find_vmlinux_btf_id(name + section_names[i].len,
+ attach_type);
+ if (err <= 0)
+ pr_warn("%s is not found in vmlinux BTF\n", name);
+ return err;
}
pr_warn("failed to identify btf_id based on ELF section name '%s'\n", name);
- err = -ESRCH;
-out:
- btf__free(btf);
- return err;
+ return -ESRCH;
}
int libbpf_attach_type_by_name(const char *name,
@@ -5709,6 +5727,37 @@ struct bpf_link *bpf_program__attach_raw_tracepoint(struct bpf_program *prog,
return (struct bpf_link *)link;
}
+struct bpf_link *bpf_program__attach_trace(struct bpf_program *prog)
+{
+ char errmsg[STRERR_BUFSIZE];
+ struct bpf_link_fd *link;
+ int prog_fd, pfd;
+
+ prog_fd = bpf_program__fd(prog);
+ if (prog_fd < 0) {
+ pr_warn("program '%s': can't attach before loaded\n",
+ bpf_program__title(prog, false));
+ return ERR_PTR(-EINVAL);
+ }
+
+ link = malloc(sizeof(*link));
+ if (!link)
+ return ERR_PTR(-ENOMEM);
+ link->link.destroy = &bpf_link__destroy_fd;
+
+ pfd = bpf_raw_tracepoint_open(NULL, prog_fd);
+ if (pfd < 0) {
+ pfd = -errno;
+ free(link);
+ pr_warn("program '%s': failed to attach to trace: %s\n",
+ bpf_program__title(prog, false),
+ libbpf_strerror_r(pfd, errmsg, sizeof(errmsg)));
+ return ERR_PTR(pfd);
+ }
+ link->fd = pfd;
+ return (struct bpf_link *)link;
+}
+
enum bpf_perf_event_ret
bpf_perf_event_read_simple(void *mmap_mem, size_t mmap_size, size_t page_size,
void **copy_mem, size_t *copy_size,
diff --git a/tools/lib/bpf/libbpf.h b/tools/lib/bpf/libbpf.h
index 6ddc0419337b..0fe47807916d 100644
--- a/tools/lib/bpf/libbpf.h
+++ b/tools/lib/bpf/libbpf.h
@@ -188,6 +188,8 @@ libbpf_prog_type_by_name(const char *name, enum bpf_prog_type *prog_type,
enum bpf_attach_type *expected_attach_type);
LIBBPF_API int libbpf_attach_type_by_name(const char *name,
enum bpf_attach_type *attach_type);
+LIBBPF_API int libbpf_find_vmlinux_btf_id(const char *name,
+ enum bpf_attach_type attach_type);
/* Accessors of bpf_program */
struct bpf_program;
@@ -248,6 +250,8 @@ LIBBPF_API struct bpf_link *
bpf_program__attach_raw_tracepoint(struct bpf_program *prog,
const char *tp_name);
+LIBBPF_API struct bpf_link *
+bpf_program__attach_trace(struct bpf_program *prog);
struct bpf_insn;
/*
diff --git a/tools/lib/bpf/libbpf.map b/tools/lib/bpf/libbpf.map
index cddb0e9d0695..52d2c9eeb0a7 100644
--- a/tools/lib/bpf/libbpf.map
+++ b/tools/lib/bpf/libbpf.map
@@ -198,9 +198,11 @@ LIBBPF_0.0.6 {
bpf_map__set_pin_path;
bpf_object__open_file;
bpf_object__open_mem;
+ bpf_program__attach_trace;
bpf_program__get_expected_attach_type;
bpf_program__get_type;
bpf_program__is_tracing;
bpf_program__set_tracing;
btf__find_by_name_kind;
+ libbpf_find_vmlinux_btf_id;
} LIBBPF_0.0.5;
--
2.23.0
next prev parent reply other threads:[~2019-11-08 6:40 UTC|newest]
Thread overview: 67+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-11-08 6:40 [PATCH v3 bpf-next 00/18] Introduce BPF trampoline Alexei Starovoitov
2019-11-08 6:40 ` [PATCH v3 bpf-next 01/18] bpf: refactor x86 JIT into helpers Alexei Starovoitov
2019-11-08 19:27 ` Andrii Nakryiko
2019-11-08 6:40 ` [PATCH v3 bpf-next 02/18] bpf: Add bpf_arch_text_poke() helper Alexei Starovoitov
2019-11-08 6:56 ` Song Liu
2019-11-08 8:23 ` Björn Töpel
2019-11-08 14:09 ` Alexei Starovoitov
2019-11-08 9:11 ` Peter Zijlstra
2019-11-08 9:36 ` Peter Zijlstra
2019-11-08 13:41 ` Alexei Starovoitov
2019-11-08 19:32 ` Alexei Starovoitov
2019-11-08 21:36 ` Peter Zijlstra
2019-11-08 21:39 ` David Miller
2019-11-11 8:14 ` Peter Zijlstra
2019-11-11 10:21 ` Daniel Borkmann
2019-11-11 16:10 ` Jonathan Corbet
2019-11-08 23:05 ` Alexei Starovoitov
2019-11-10 10:54 ` Thomas Gleixner
2019-11-08 6:40 ` [PATCH v3 bpf-next 03/18] bpf: Introduce BPF trampoline Alexei Starovoitov
2019-11-08 7:04 ` Song Liu
2019-11-08 6:40 ` [PATCH v3 bpf-next 04/18] libbpf: Introduce btf__find_by_name_kind() Alexei Starovoitov
2019-11-08 7:05 ` Song Liu
2019-11-08 19:21 ` Andrii Nakryiko
2019-11-08 6:40 ` Alexei Starovoitov [this message]
2019-11-08 7:12 ` [PATCH v3 bpf-next 05/18] libbpf: Add support to attach to fentry/fexit tracing progs Song Liu
2019-11-08 19:44 ` Andrii Nakryiko
2019-11-08 6:40 ` [PATCH v3 bpf-next 06/18] selftest/bpf: Simple test for fentry/fexit Alexei Starovoitov
2019-11-08 6:40 ` [PATCH v3 bpf-next 07/18] bpf: Add kernel test functions for fentry testing Alexei Starovoitov
2019-11-08 6:40 ` [PATCH v3 bpf-next 08/18] selftests/bpf: Add test for BPF trampoline Alexei Starovoitov
2019-11-08 6:40 ` [PATCH v3 bpf-next 09/18] selftests/bpf: Add fexit tests " Alexei Starovoitov
2019-11-08 6:40 ` [PATCH v3 bpf-next 10/18] selftests/bpf: Add combined fentry/fexit test Alexei Starovoitov
2019-11-08 7:14 ` Song Liu
2019-11-08 6:40 ` [PATCH v3 bpf-next 11/18] selftests/bpf: Add stress test for maximum number of progs Alexei Starovoitov
2019-11-08 7:24 ` Song Liu
2019-11-08 6:40 ` [PATCH v3 bpf-next 12/18] bpf: Reserve space for BPF trampoline in BPF programs Alexei Starovoitov
2019-11-08 7:25 ` Song Liu
2019-11-08 6:40 ` [PATCH v3 bpf-next 13/18] bpf: Fix race in btf_resolve_helper_id() Alexei Starovoitov
2019-11-08 7:32 ` Song Liu
2019-11-08 19:58 ` Andrii Nakryiko
2019-11-08 6:40 ` [PATCH v3 bpf-next 14/18] bpf: Compare BTF types of functions arguments with actual types Alexei Starovoitov
2019-11-08 17:28 ` Song Liu
2019-11-08 17:32 ` Song Liu
2019-11-08 17:57 ` Alexei Starovoitov
2019-11-08 17:59 ` Song Liu
2019-11-08 23:46 ` Andrii Nakryiko
2019-11-08 6:40 ` [PATCH v3 bpf-next 15/18] bpf: Support attaching tracing BPF program to other BPF programs Alexei Starovoitov
2019-11-08 18:49 ` Song Liu
2019-11-08 18:59 ` Alexei Starovoitov
2019-11-08 20:17 ` Toke Høiland-Jørgensen
2019-11-08 21:14 ` Alexei Starovoitov
2019-11-08 21:32 ` Toke Høiland-Jørgensen
2019-11-10 7:17 ` Andrii Nakryiko
2019-11-11 23:04 ` Alexei Starovoitov
2019-11-12 4:38 ` Andrii Nakryiko
2019-11-12 4:47 ` Alexei Starovoitov
2019-11-08 6:40 ` [PATCH v3 bpf-next 16/18] libbpf: Add support for attaching BPF programs " Alexei Starovoitov
2019-11-08 18:57 ` Song Liu
2019-11-08 19:13 ` Alexei Starovoitov
2019-11-08 19:14 ` Song Liu
2019-11-10 16:56 ` Andrii Nakryiko
2019-11-08 6:40 ` [PATCH v3 bpf-next 17/18] selftests/bpf: Extend test_pkt_access test Alexei Starovoitov
2019-11-08 19:03 ` Song Liu
2019-11-10 16:58 ` Andrii Nakryiko
2019-11-08 6:40 ` [PATCH v3 bpf-next 18/18] selftests/bpf: Add a test for attaching BPF prog to another BPF prog and subprog Alexei Starovoitov
2019-11-08 19:13 ` Song Liu
2019-11-10 17:04 ` Andrii Nakryiko
2019-11-11 23:07 ` Alexei Starovoitov
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20191108064039.2041889-6-ast@kernel.org \
--to=ast@kernel.org \
--cc=bpf@vger.kernel.org \
--cc=daniel@iogearbox.net \
--cc=davem@davemloft.net \
--cc=kernel-team@fb.com \
--cc=netdev@vger.kernel.org \
--cc=x86@kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).