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authorMartin KaFai Lau <kafai@fb.com>2021-03-24 18:52:14 -0700
committerAlexei Starovoitov <ast@kernel.org>2021-03-26 20:41:51 -0700
commit774e132e83d0f10a7ebbfe7db1debdaed6013f83 (patch)
tree7221ed70d189d87b1c69071edb4402416060eb5c /tools/lib
parent933d1aa32409ef4209c8065ee4ede68236659cd2 (diff)
libbpf: Refactor codes for finding btf id of a kernel symbol
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> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20210325015214.1547069-1-kafai@fb.com
Diffstat (limited to 'tools/lib')
-rw-r--r--tools/lib/bpf/libbpf.c44
1 files changed, 33 insertions, 11 deletions
diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index e289155510ca..2f5595ae0b84 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -1921,9 +1921,9 @@ 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";
@@ -1945,6 +1945,11 @@ 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
@@ -7395,18 +7400,17 @@ out:
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)
@@ -7416,17 +7420,35 @@ 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;