From: Martin KaFai Lau <kafai@fb.com>
To: <bpf@vger.kernel.org>
Cc: Alexei Starovoitov <ast@kernel.org>,
Daniel Borkmann <daniel@iogearbox.net>, <kernel-team@fb.com>,
<netdev@vger.kernel.org>
Subject: [PATCH bpf-next 09/15] libbpf: Refactor codes for finding btf id of a kernel symbol
Date: Mon, 15 Mar 2021 18:14:32 -0700 [thread overview]
Message-ID: <20210316011432.4178797-1-kafai@fb.com> (raw)
In-Reply-To: <20210316011336.4173585-1-kafai@fb.com>
This patch refactors code, that finds kernel btf_id by kind
and symbol name, to a new function find_ksym_btf_id().
It also adds a new helper __btf_kind_str() to return
a string by the numeric kind value.
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
---
tools/lib/bpf/libbpf.c | 44 +++++++++++++++++++++++++++++++-----------
1 file changed, 33 insertions(+), 11 deletions(-)
diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index 7d5f9b7877bc..8355b786b3db 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -1929,9 +1929,9 @@ resolve_func_ptr(const struct btf *btf, __u32 id, __u32 *res_id)
return btf_is_func_proto(t) ? t : NULL;
}
-static const char *btf_kind_str(const struct btf_type *t)
+static const char *__btf_kind_str(__u16 kind)
{
- switch (btf_kind(t)) {
+ switch (kind) {
case BTF_KIND_UNKN: return "void";
case BTF_KIND_INT: return "int";
case BTF_KIND_PTR: return "ptr";
@@ -1953,6 +1953,11 @@ static const char *btf_kind_str(const struct btf_type *t)
}
}
+static const char *btf_kind_str(const struct btf_type *t)
+{
+ return __btf_kind_str(btf_kind(t));
+}
+
/*
* Fetch integer attribute of BTF map definition. Such attributes are
* represented using a pointer to an array, in which dimensionality of array
@@ -7403,18 +7408,17 @@ static int bpf_object__read_kallsyms_file(struct bpf_object *obj)
return err;
}
-static int bpf_object__resolve_ksym_var_btf_id(struct bpf_object *obj,
- struct extern_desc *ext)
+static int find_ksym_btf_id(struct bpf_object *obj, const char *ksym_name,
+ __u16 kind, struct btf **res_btf,
+ int *res_btf_fd)
{
- const struct btf_type *targ_var, *targ_type;
- __u32 targ_type_id, local_type_id;
- const char *targ_var_name;
int i, id, btf_fd, err;
struct btf *btf;
btf = obj->btf_vmlinux;
btf_fd = 0;
- id = btf__find_by_name_kind(btf, ext->name, BTF_KIND_VAR);
+ id = btf__find_by_name_kind(btf, ksym_name, kind);
+
if (id == -ENOENT) {
err = load_module_btfs(obj);
if (err)
@@ -7424,17 +7428,35 @@ static int bpf_object__resolve_ksym_var_btf_id(struct bpf_object *obj,
btf = obj->btf_modules[i].btf;
/* we assume module BTF FD is always >0 */
btf_fd = obj->btf_modules[i].fd;
- id = btf__find_by_name_kind(btf, ext->name, BTF_KIND_VAR);
+ id = btf__find_by_name_kind(btf, ksym_name, kind);
if (id != -ENOENT)
break;
}
}
if (id <= 0) {
- pr_warn("extern (var ksym) '%s': failed to find BTF ID in kernel BTF(s).\n",
- ext->name);
+ pr_warn("extern (%s ksym) '%s': failed to find BTF ID in kernel BTF(s).\n",
+ __btf_kind_str(kind), ksym_name);
return -ESRCH;
}
+ *res_btf = btf;
+ *res_btf_fd = btf_fd;
+ return id;
+}
+
+static int bpf_object__resolve_ksym_var_btf_id(struct bpf_object *obj,
+ struct extern_desc *ext)
+{
+ const struct btf_type *targ_var, *targ_type;
+ __u32 targ_type_id, local_type_id;
+ const char *targ_var_name;
+ int id, btf_fd = 0, err;
+ struct btf *btf = NULL;
+
+ id = find_ksym_btf_id(obj, ext->name, BTF_KIND_VAR, &btf, &btf_fd);
+ if (id < 0)
+ return id;
+
/* find local type_id */
local_type_id = ext->ksym.type_id;
--
2.30.2
next prev parent reply other threads:[~2021-03-16 1:15 UTC|newest]
Thread overview: 49+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-03-16 1:13 [PATCH bpf-next 00/15] Support calling kernel function Martin KaFai Lau
2021-03-16 1:13 ` [PATCH bpf-next 01/15] bpf: Simplify freeing logic in linfo and jited_linfo Martin KaFai Lau
2021-03-16 1:13 ` [PATCH bpf-next 02/15] bpf: btf: Support parsing extern func Martin KaFai Lau
2021-03-18 22:53 ` Andrii Nakryiko
2021-03-18 23:39 ` Martin KaFai Lau
2021-03-19 4:13 ` Andrii Nakryiko
2021-03-19 5:29 ` Martin KaFai Lau
2021-03-19 21:27 ` Andrii Nakryiko
2021-03-19 22:19 ` Martin KaFai Lau
2021-03-19 22:29 ` Andrii Nakryiko
2021-03-19 22:45 ` Martin KaFai Lau
2021-03-19 23:02 ` Andrii Nakryiko
2021-03-20 0:13 ` Martin KaFai Lau
2021-03-20 17:18 ` Andrii Nakryiko
2021-03-23 4:55 ` Martin KaFai Lau
2021-03-16 1:13 ` [PATCH bpf-next 03/15] bpf: Refactor btf_check_func_arg_match Martin KaFai Lau
2021-03-18 23:32 ` Andrii Nakryiko
2021-03-19 19:32 ` Martin KaFai Lau
2021-03-19 21:51 ` Andrii Nakryiko
2021-03-20 0:10 ` Alexei Starovoitov
2021-03-20 17:13 ` Andrii Nakryiko
2021-03-16 1:14 ` [PATCH bpf-next 04/15] bpf: Support bpf program calling kernel function Martin KaFai Lau
2021-03-19 1:03 ` Andrii Nakryiko
2021-03-19 1:51 ` Alexei Starovoitov
2021-03-19 19:47 ` Martin KaFai Lau
2021-03-16 1:14 ` [PATCH bpf-next 05/15] bpf: Support kernel function call in x86-32 Martin KaFai Lau
2021-03-16 1:14 ` [PATCH bpf-next 06/15] tcp: Rename bictcp function prefix to cubictcp Martin KaFai Lau
2021-03-16 1:14 ` [PATCH bpf-next 07/15] bpf: tcp: White list some tcp cong functions to be called by bpf-tcp-cc Martin KaFai Lau
2021-03-19 1:19 ` Andrii Nakryiko
2021-03-16 1:14 ` [PATCH bpf-next 08/15] libbpf: Refactor bpf_object__resolve_ksyms_btf_id Martin KaFai Lau
2021-03-19 2:53 ` Andrii Nakryiko
2021-03-16 1:14 ` Martin KaFai Lau [this message]
2021-03-19 3:14 ` [PATCH bpf-next 09/15] libbpf: Refactor codes for finding btf id of a kernel symbol Andrii Nakryiko
2021-03-16 1:14 ` [PATCH bpf-next 10/15] libbpf: Rename RELO_EXTERN to RELO_EXTERN_VAR Martin KaFai Lau
2021-03-19 3:15 ` Andrii Nakryiko
2021-03-16 1:14 ` [PATCH bpf-next 11/15] libbpf: Record extern sym relocation first Martin KaFai Lau
2021-03-19 3:16 ` Andrii Nakryiko
2021-03-16 1:14 ` [PATCH bpf-next 12/15] libbpf: Support extern kernel function Martin KaFai Lau
2021-03-19 4:11 ` Andrii Nakryiko
2021-03-19 5:06 ` Martin KaFai Lau
2021-03-19 21:38 ` Andrii Nakryiko
2021-03-16 1:14 ` [PATCH bpf-next 13/15] bpf: selftests: Rename bictcp to bpf_cubic Martin KaFai Lau
2021-03-19 4:14 ` Andrii Nakryiko
2021-03-16 1:15 ` [PATCH bpf-next 14/15] bpf: selftest: bpf_cubic and bpf_dctcp calling kernel functions Martin KaFai Lau
2021-03-19 4:15 ` Andrii Nakryiko
2021-03-16 1:15 ` [PATCH bpf-next 15/15] bpf: selftest: Add kfunc_call test Martin KaFai Lau
2021-03-16 3:39 ` kernel test robot
2021-03-19 4:21 ` Andrii Nakryiko
2021-03-19 5:40 ` Martin KaFai Lau
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