From: Yonghong Song <yhs@fb.com>
To: Andrii Nakryiko <andriin@fb.com>, <bpf@vger.kernel.org>,
Martin KaFai Lau <kafai@fb.com>, <netdev@vger.kernel.org>
Cc: Alexei Starovoitov <ast@fb.com>,
Daniel Borkmann <daniel@iogearbox.net>, <kernel-team@fb.com>
Subject: [PATCH bpf-next v4 02/21] bpf: allow loading of a bpf_iter program
Date: Sat, 9 May 2020 10:59:00 -0700 [thread overview]
Message-ID: <20200509175900.2474947-1-yhs@fb.com> (raw)
In-Reply-To: <20200509175859.2474608-1-yhs@fb.com>
A bpf_iter program is a tracing program with attach type
BPF_TRACE_ITER. The load attribute
attach_btf_id
is used by the verifier against a particular kernel function,
which represents a target, e.g., __bpf_iter__bpf_map
for target bpf_map which is implemented later.
The program return value must be 0 or 1 for now.
0 : successful, except potential seq_file buffer overflow
which is handled by seq_file reader.
1 : request to restart the same object
In the future, other return values may be used for filtering or
teminating the iterator.
Acked-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Yonghong Song <yhs@fb.com>
---
include/linux/bpf.h | 3 +++
include/uapi/linux/bpf.h | 1 +
kernel/bpf/bpf_iter.c | 36 ++++++++++++++++++++++++++++++++++
kernel/bpf/verifier.c | 21 ++++++++++++++++++++
tools/include/uapi/linux/bpf.h | 1 +
5 files changed, 62 insertions(+)
diff --git a/include/linux/bpf.h b/include/linux/bpf.h
index 40c78b86fe38..f28bdd714754 100644
--- a/include/linux/bpf.h
+++ b/include/linux/bpf.h
@@ -1127,6 +1127,8 @@ struct bpf_link *bpf_link_get_from_fd(u32 ufd);
int bpf_obj_pin_user(u32 ufd, const char __user *pathname);
int bpf_obj_get_user(const char __user *pathname, int flags);
+#define BPF_ITER_FUNC_PREFIX "__bpf_iter__"
+
typedef int (*bpf_iter_init_seq_priv_t)(void *private_data);
typedef void (*bpf_iter_fini_seq_priv_t)(void *private_data);
@@ -1140,6 +1142,7 @@ struct bpf_iter_reg {
int bpf_iter_reg_target(struct bpf_iter_reg *reg_info);
void bpf_iter_unreg_target(const char *target);
+bool bpf_iter_prog_supported(struct bpf_prog *prog);
int bpf_percpu_hash_copy(struct bpf_map *map, void *key, void *value);
int bpf_percpu_array_copy(struct bpf_map *map, void *key, void *value);
diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h
index 6e5e7caa3739..c8a5325cc8d0 100644
--- a/include/uapi/linux/bpf.h
+++ b/include/uapi/linux/bpf.h
@@ -218,6 +218,7 @@ enum bpf_attach_type {
BPF_TRACE_FEXIT,
BPF_MODIFY_RETURN,
BPF_LSM_MAC,
+ BPF_TRACE_ITER,
__MAX_BPF_ATTACH_TYPE
};
diff --git a/kernel/bpf/bpf_iter.c b/kernel/bpf/bpf_iter.c
index 5a8119d17d14..dec182d8395a 100644
--- a/kernel/bpf/bpf_iter.c
+++ b/kernel/bpf/bpf_iter.c
@@ -12,6 +12,7 @@ struct bpf_iter_target_info {
bpf_iter_init_seq_priv_t init_seq_private;
bpf_iter_fini_seq_priv_t fini_seq_private;
u32 seq_priv_size;
+ u32 btf_id; /* cached value */
};
static struct list_head targets = LIST_HEAD_INIT(targets);
@@ -57,3 +58,38 @@ void bpf_iter_unreg_target(const char *target)
WARN_ON(found == false);
}
+
+static void cache_btf_id(struct bpf_iter_target_info *tinfo,
+ struct bpf_prog *prog)
+{
+ tinfo->btf_id = prog->aux->attach_btf_id;
+}
+
+bool bpf_iter_prog_supported(struct bpf_prog *prog)
+{
+ const char *attach_fname = prog->aux->attach_func_name;
+ u32 prog_btf_id = prog->aux->attach_btf_id;
+ const char *prefix = BPF_ITER_FUNC_PREFIX;
+ struct bpf_iter_target_info *tinfo;
+ int prefix_len = strlen(prefix);
+ bool supported = false;
+
+ if (strncmp(attach_fname, prefix, prefix_len))
+ return false;
+
+ mutex_lock(&targets_mutex);
+ list_for_each_entry(tinfo, &targets, list) {
+ if (tinfo->btf_id && tinfo->btf_id == prog_btf_id) {
+ supported = true;
+ break;
+ }
+ if (!strcmp(attach_fname + prefix_len, tinfo->target)) {
+ cache_btf_id(tinfo, prog);
+ supported = true;
+ break;
+ }
+ }
+ mutex_unlock(&targets_mutex);
+
+ return supported;
+}
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index 70ad009577f8..d725ff7d11db 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -7101,6 +7101,10 @@ static int check_return_code(struct bpf_verifier_env *env)
return 0;
range = tnum_const(0);
break;
+ case BPF_PROG_TYPE_TRACING:
+ if (env->prog->expected_attach_type != BPF_TRACE_ITER)
+ return 0;
+ break;
default:
return 0;
}
@@ -10481,6 +10485,7 @@ static int check_attach_btf_id(struct bpf_verifier_env *env)
struct bpf_prog *tgt_prog = prog->aux->linked_prog;
u32 btf_id = prog->aux->attach_btf_id;
const char prefix[] = "btf_trace_";
+ struct btf_func_model fmodel;
int ret = 0, subprog = -1, i;
struct bpf_trampoline *tr;
const struct btf_type *t;
@@ -10622,6 +10627,22 @@ static int check_attach_btf_id(struct bpf_verifier_env *env)
prog->aux->attach_func_proto = t;
prog->aux->attach_btf_trace = true;
return 0;
+ case BPF_TRACE_ITER:
+ if (!btf_type_is_func(t)) {
+ verbose(env, "attach_btf_id %u is not a function\n",
+ btf_id);
+ return -EINVAL;
+ }
+ t = btf_type_by_id(btf, t->type);
+ if (!btf_type_is_func_proto(t))
+ return -EINVAL;
+ prog->aux->attach_func_name = tname;
+ prog->aux->attach_func_proto = t;
+ if (!bpf_iter_prog_supported(prog))
+ return -EINVAL;
+ ret = btf_distill_func_proto(&env->log, btf, t,
+ tname, &fmodel);
+ return ret;
default:
if (!prog_extension)
return -EINVAL;
diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h
index 6e5e7caa3739..c8a5325cc8d0 100644
--- a/tools/include/uapi/linux/bpf.h
+++ b/tools/include/uapi/linux/bpf.h
@@ -218,6 +218,7 @@ enum bpf_attach_type {
BPF_TRACE_FEXIT,
BPF_MODIFY_RETURN,
BPF_LSM_MAC,
+ BPF_TRACE_ITER,
__MAX_BPF_ATTACH_TYPE
};
--
2.24.1
next prev parent reply other threads:[~2020-05-09 17:59 UTC|newest]
Thread overview: 42+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-05-09 17:58 [PATCH bpf-next v4 00/21] bpf: implement bpf iterator for kernel data Yonghong Song
2020-05-09 17:58 ` [PATCH bpf-next v4 01/21] bpf: implement an interface to register bpf_iter targets Yonghong Song
2020-05-09 17:59 ` Yonghong Song [this message]
2020-05-10 0:41 ` [PATCH bpf-next v4 02/21] bpf: allow loading of a bpf_iter program Alexei Starovoitov
2020-05-10 5:07 ` Yonghong Song
2020-05-12 15:41 ` Yonghong Song
2020-05-12 16:25 ` Alexei Starovoitov
2020-05-12 16:29 ` Yonghong Song
2020-05-09 17:59 ` [PATCH bpf-next v4 03/21] bpf: support bpf tracing/iter programs for BPF_LINK_CREATE Yonghong Song
2020-05-09 17:59 ` [PATCH bpf-next v4 04/21] bpf: support bpf tracing/iter programs for BPF_LINK_UPDATE Yonghong Song
2020-05-09 17:59 ` [PATCH bpf-next v4 05/21] bpf: implement bpf_seq_read() for bpf iterator Yonghong Song
2020-05-10 0:30 ` Alexei Starovoitov
2020-05-10 4:51 ` Yonghong Song
2020-05-09 17:59 ` [PATCH bpf-next v4 06/21] bpf: create anonymous " Yonghong Song
2020-05-09 17:59 ` [PATCH bpf-next v4 07/21] bpf: create file " Yonghong Song
2020-05-09 17:59 ` [PATCH bpf-next v4 08/21] bpf: implement common macros/helpers for target iterators Yonghong Song
2020-05-09 17:59 ` [PATCH bpf-next v4 09/21] bpf: add bpf_map iterator Yonghong Song
2020-05-09 17:59 ` [PATCH bpf-next v4 10/21] net: bpf: add netlink and ipv6_route bpf_iter targets Yonghong Song
2020-05-09 17:59 ` [PATCH bpf-next v4 11/21] bpf: add task and task/file iterator targets Yonghong Song
2020-05-09 17:59 ` [PATCH bpf-next v4 12/21] bpf: add PTR_TO_BTF_ID_OR_NULL support Yonghong Song
2020-05-10 0:50 ` Alexei Starovoitov
2020-05-10 5:18 ` Yonghong Song
2020-05-10 16:11 ` Alexei Starovoitov
2020-05-10 17:05 ` Yonghong Song
2020-05-09 17:59 ` [PATCH bpf-next v4 13/21] bpf: add bpf_seq_printf and bpf_seq_write helpers Yonghong Song
2020-05-09 17:59 ` [PATCH bpf-next v4 14/21] bpf: handle spilled PTR_TO_BTF_ID properly when checking stack_boundary Yonghong Song
2020-05-09 17:59 ` [PATCH bpf-next v4 15/21] bpf: support variable length array in tracing programs Yonghong Song
2020-05-09 17:59 ` [PATCH bpf-next v4 16/21] tools/libbpf: add bpf_iter support Yonghong Song
2020-05-10 0:35 ` Alexei Starovoitov
2020-05-10 5:06 ` Yonghong Song
2020-05-10 16:09 ` Alexei Starovoitov
2020-05-10 17:04 ` Yonghong Song
2020-05-09 17:59 ` [PATCH bpf-next v4 17/21] tools/libpf: add offsetof/container_of macro in bpf_helpers.h Yonghong Song
2020-05-09 17:59 ` [PATCH bpf-next v4 18/21] tools/bpftool: add bpf_iter support for bptool Yonghong Song
2020-05-09 17:59 ` [PATCH bpf-next v4 19/21] tools/bpf: selftests: add iterator programs for ipv6_route and netlink Yonghong Song
2020-05-09 17:59 ` [PATCH bpf-next v4 20/21] tools/bpf: selftests: add iter progs for bpf_map/task/task_file Yonghong Song
2020-05-09 17:59 ` [PATCH bpf-next v4 21/21] tools/bpf: selftests: add bpf_iter selftests Yonghong Song
2020-05-10 0:34 ` Alexei Starovoitov
2020-05-10 5:01 ` Yonghong Song
2020-05-10 16:14 ` Alexei Starovoitov
2020-05-10 0:27 ` [PATCH bpf-next v4 00/21] bpf: implement bpf iterator for kernel data Alexei Starovoitov
2020-05-10 4:47 ` Yonghong Song
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=20200509175900.2474947-1-yhs@fb.com \
--to=yhs@fb.com \
--cc=andriin@fb.com \
--cc=ast@fb.com \
--cc=bpf@vger.kernel.org \
--cc=daniel@iogearbox.net \
--cc=kafai@fb.com \
--cc=kernel-team@fb.com \
--cc=netdev@vger.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).