mirror/libbpf
1
0
Fork 0
mirror of https://github.com/netdata/libbpf.git synced 2026-04-03 15:19:07 +08:00
Code Issues Packages Projects Releases Wiki Activity

libbpf: Support BTF_KIND_TYPE_TAG

Browse Source 
Add libbpf support for BTF_KIND_TYPE_TAG.

Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20211112012614.1505315-1-yhs@fb.com
This commit is contained in:
Yonghong Song
2021-11-11 17:26:14 -08:00
committed by Andrii Nakryiko
parent d932a1a46b
commit 98181e0546
6 changed files with 73 additions and 2 deletions
Download Patch File Download Diff File Expand all files Collapse all files

31
src/libbpf.c
View File

@@ -197,6 +197,8 @@ enum kern_feature_id {
FEAT_PERF_LINK,
/* BTF_KIND_DECL_TAG support */
FEAT_BTF_DECL_TAG,
/* BTF_KIND_TYPE_TAG support */
FEAT_BTF_TYPE_TAG,
__FEAT_CNT,
};
@@ -2076,6 +2078,7 @@ static const char *__btf_kind_str(__u16 kind)
case BTF_KIND_DATASEC: return "datasec";
case BTF_KIND_FLOAT: return "float";
case BTF_KIND_DECL_TAG: return "decl_tag";
case BTF_KIND_TYPE_TAG: return "type_tag";
default: return "unknown";
}
}
@@ -2588,8 +2591,10 @@ static bool btf_needs_sanitization(struct bpf_object *obj)
bool has_float = kernel_supports(obj, FEAT_BTF_FLOAT);
bool has_func = kernel_supports(obj, FEAT_BTF_FUNC);
bool has_decl_tag = kernel_supports(obj, FEAT_BTF_DECL_TAG);
bool has_type_tag = kernel_supports(obj, FEAT_BTF_TYPE_TAG);
return !has_func || !has_datasec || !has_func_global || !has_float || !has_decl_tag;
return !has_func || !has_datasec || !has_func_global || !has_float ||
!has_decl_tag || !has_type_tag;
}
static void bpf_object__sanitize_btf(struct bpf_object *obj, struct btf *btf)
@@ -2599,6 +2604,7 @@ static void bpf_object__sanitize_btf(struct bpf_object *obj, struct btf *btf)
bool has_float = kernel_supports(obj, FEAT_BTF_FLOAT);
bool has_func = kernel_supports(obj, FEAT_BTF_FUNC);
bool has_decl_tag = kernel_supports(obj, FEAT_BTF_DECL_TAG);
bool has_type_tag = kernel_supports(obj, FEAT_BTF_TYPE_TAG);
struct btf_type *t;
int i, j, vlen;
@@ -2657,6 +2663,10 @@ static void bpf_object__sanitize_btf(struct bpf_object *obj, struct btf *btf)
*/
t->name_off = 0;
t->info = BTF_INFO_ENC(BTF_KIND_STRUCT, 0, 0);
} else if (!has_type_tag && btf_is_type_tag(t)) {
/* replace TYPE_TAG with a CONST */
t->name_off = 0;
t->info = BTF_INFO_ENC(BTF_KIND_CONST, 0, 0);
}
}
}
@@ -4460,6 +4470,22 @@ static int probe_kern_btf_decl_tag(void)
strs, sizeof(strs)));
}
static int probe_kern_btf_type_tag(void)
{
static const char strs[] = "\0tag";
__u32 types[] = {
/* int */
BTF_TYPE_INT_ENC(0, BTF_INT_SIGNED, 0, 32, 4), /* [1] */
/* attr */
BTF_TYPE_TYPE_TAG_ENC(1, 1), /* [2] */
/* ptr */
BTF_TYPE_ENC(0, BTF_INFO_ENC(BTF_KIND_PTR, 0, 0), 2), /* [3] */
};
return probe_fd(libbpf__load_raw_btf((char *)types, sizeof(types),
strs, sizeof(strs)));
}
static int probe_kern_array_mmap(void)
{
struct bpf_create_map_attr attr = {
@@ -4657,6 +4683,9 @@ static struct kern_feature_desc {
[FEAT_BTF_DECL_TAG] = {
"BTF_KIND_DECL_TAG support", probe_kern_btf_decl_tag,
},
[FEAT_BTF_TYPE_TAG] = {
"BTF_KIND_TYPE_TAG support", probe_kern_btf_type_tag,
},
};
static bool kernel_supports(const struct bpf_object *obj, enum kern_feature_id feat_id)