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-rw-r--r--tools/lib/bpf/btf.c16
-rw-r--r--tools/lib/bpf/btf.h4
-rw-r--r--tools/lib/bpf/libbpf.c24
-rw-r--r--tools/lib/bpf/libbpf_internal.h25
4 files changed, 40 insertions, 29 deletions
diff --git a/tools/lib/bpf/btf.c b/tools/lib/bpf/btf.c
index 1aa189a9112a..3eae8d1addfa 100644
--- a/tools/lib/bpf/btf.c
+++ b/tools/lib/bpf/btf.c
@@ -888,14 +888,14 @@ static int btf_ext_setup_line_info(struct btf_ext *btf_ext)
return btf_ext_setup_info(btf_ext, &param);
}
-static int btf_ext_setup_offset_reloc(struct btf_ext *btf_ext)
+static int btf_ext_setup_field_reloc(struct btf_ext *btf_ext)
{
struct btf_ext_sec_setup_param param = {
- .off = btf_ext->hdr->offset_reloc_off,
- .len = btf_ext->hdr->offset_reloc_len,
- .min_rec_size = sizeof(struct bpf_offset_reloc),
- .ext_info = &btf_ext->offset_reloc_info,
- .desc = "offset_reloc",
+ .off = btf_ext->hdr->field_reloc_off,
+ .len = btf_ext->hdr->field_reloc_len,
+ .min_rec_size = sizeof(struct bpf_field_reloc),
+ .ext_info = &btf_ext->field_reloc_info,
+ .desc = "field_reloc",
};
return btf_ext_setup_info(btf_ext, &param);
@@ -975,9 +975,9 @@ struct btf_ext *btf_ext__new(__u8 *data, __u32 size)
goto done;
if (btf_ext->hdr->hdr_len <
- offsetofend(struct btf_ext_header, offset_reloc_len))
+ offsetofend(struct btf_ext_header, field_reloc_len))
goto done;
- err = btf_ext_setup_offset_reloc(btf_ext);
+ err = btf_ext_setup_field_reloc(btf_ext);
if (err)
goto done;
diff --git a/tools/lib/bpf/btf.h b/tools/lib/bpf/btf.h
index 9cb44b4fbf60..b18994116a44 100644
--- a/tools/lib/bpf/btf.h
+++ b/tools/lib/bpf/btf.h
@@ -60,8 +60,8 @@ struct btf_ext_header {
__u32 line_info_len;
/* optional part of .BTF.ext header */
- __u32 offset_reloc_off;
- __u32 offset_reloc_len;
+ __u32 field_reloc_off;
+ __u32 field_reloc_len;
};
LIBBPF_API void btf__free(struct btf *btf);
diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index a02cdedc4e3f..d6c7699de405 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -2326,7 +2326,7 @@ static bool str_is_empty(const char *s)
}
/*
- * Turn bpf_offset_reloc into a low- and high-level spec representation,
+ * Turn bpf_field_reloc into a low- and high-level spec representation,
* validating correctness along the way, as well as calculating resulting
* field offset (in bytes), specified by accessor string. Low-level spec
* captures every single level of nestedness, including traversing anonymous
@@ -2977,7 +2977,7 @@ static void *u32_as_hash_key(__u32 x)
* types should be compatible (see bpf_core_fields_are_compat for details).
* 3. It is supported and expected that there might be multiple flavors
* matching the spec. As long as all the specs resolve to the same set of
- * offsets across all candidates, there is not error. If there is any
+ * offsets across all candidates, there is no error. If there is any
* ambiguity, CO-RE relocation will fail. This is necessary to accomodate
* imprefection of BTF deduplication, which can cause slight duplication of
* the same BTF type, if some directly or indirectly referenced (by
@@ -2992,12 +2992,12 @@ static void *u32_as_hash_key(__u32 x)
* CPU-wise compared to prebuilding a map from all local type names to
* a list of candidate type names. It's also sped up by caching resolved
* list of matching candidates per each local "root" type ID, that has at
- * least one bpf_offset_reloc associated with it. This list is shared
+ * least one bpf_field_reloc associated with it. This list is shared
* between multiple relocations for the same type ID and is updated as some
* of the candidates are pruned due to structural incompatibility.
*/
-static int bpf_core_reloc_offset(struct bpf_program *prog,
- const struct bpf_offset_reloc *relo,
+static int bpf_core_reloc_field(struct bpf_program *prog,
+ const struct bpf_field_reloc *relo,
int relo_idx,
const struct btf *local_btf,
const struct btf *targ_btf,
@@ -3106,10 +3106,10 @@ static int bpf_core_reloc_offset(struct bpf_program *prog,
}
static int
-bpf_core_reloc_offsets(struct bpf_object *obj, const char *targ_btf_path)
+bpf_core_reloc_fields(struct bpf_object *obj, const char *targ_btf_path)
{
const struct btf_ext_info_sec *sec;
- const struct bpf_offset_reloc *rec;
+ const struct bpf_field_reloc *rec;
const struct btf_ext_info *seg;
struct hashmap_entry *entry;
struct hashmap *cand_cache = NULL;
@@ -3134,7 +3134,7 @@ bpf_core_reloc_offsets(struct bpf_object *obj, const char *targ_btf_path)
goto out;
}
- seg = &obj->btf_ext->offset_reloc_info;
+ seg = &obj->btf_ext->field_reloc_info;
for_each_btf_ext_sec(seg, sec) {
sec_name = btf__name_by_offset(obj->btf, sec->sec_name_off);
if (str_is_empty(sec_name)) {
@@ -3153,8 +3153,8 @@ bpf_core_reloc_offsets(struct bpf_object *obj, const char *targ_btf_path)
sec_name, sec->num_info);
for_each_btf_ext_rec(seg, sec, i, rec) {
- err = bpf_core_reloc_offset(prog, rec, i, obj->btf,
- targ_btf, cand_cache);
+ err = bpf_core_reloc_field(prog, rec, i, obj->btf,
+ targ_btf, cand_cache);
if (err) {
pr_warning("prog '%s': relo #%d: failed to relocate: %d\n",
sec_name, i, err);
@@ -3179,8 +3179,8 @@ bpf_object__relocate_core(struct bpf_object *obj, const char *targ_btf_path)
{
int err = 0;
- if (obj->btf_ext->offset_reloc_info.len)
- err = bpf_core_reloc_offsets(obj, targ_btf_path);
+ if (obj->btf_ext->field_reloc_info.len)
+ err = bpf_core_reloc_fields(obj, targ_btf_path);
return err;
}
diff --git a/tools/lib/bpf/libbpf_internal.h b/tools/lib/bpf/libbpf_internal.h
index f51444fc7eb7..5bfe85d4f8aa 100644
--- a/tools/lib/bpf/libbpf_internal.h
+++ b/tools/lib/bpf/libbpf_internal.h
@@ -110,7 +110,7 @@ struct btf_ext {
};
struct btf_ext_info func_info;
struct btf_ext_info line_info;
- struct btf_ext_info offset_reloc_info;
+ struct btf_ext_info field_reloc_info;
__u32 data_size;
};
@@ -135,13 +135,23 @@ struct bpf_line_info_min {
__u32 line_col;
};
-/* The minimum bpf_offset_reloc checked by the loader
+/* bpf_field_info_kind encodes which aspect of captured field has to be
+ * adjusted by relocations. Currently supported values are:
+ * - BPF_FIELD_BYTE_OFFSET: field offset (in bytes);
+ * - BPF_FIELD_EXISTS: field existence (1, if field exists; 0, otherwise);
+ */
+enum bpf_field_info_kind {
+ BPF_FIELD_BYTE_OFFSET = 0, /* field byte offset */
+ BPF_FIELD_EXISTS = 2, /* field existence in target kernel */
+};
+
+/* The minimum bpf_field_reloc checked by the loader
*
- * Offset relocation captures the following data:
+ * Field relocation captures the following data:
* - insn_off - instruction offset (in bytes) within a BPF program that needs
- * its insn->imm field to be relocated with actual offset;
+ * its insn->imm field to be relocated with actual field info;
* - type_id - BTF type ID of the "root" (containing) entity of a relocatable
- * offset;
+ * field;
* - access_str_off - offset into corresponding .BTF string section. String
* itself encodes an accessed field using a sequence of field and array
* indicies, separated by colon (:). It's conceptually very close to LLVM's
@@ -172,15 +182,16 @@ struct bpf_line_info_min {
* bpf_probe_read(&dst, sizeof(dst),
* __builtin_preserve_access_index(&src->a.b.c));
*
- * In this case Clang will emit offset relocation recording necessary data to
+ * In this case Clang will emit field relocation recording necessary data to
* be able to find offset of embedded `a.b.c` field within `src` struct.
*
* [0] https://llvm.org/docs/LangRef.html#getelementptr-instruction
*/
-struct bpf_offset_reloc {
+struct bpf_field_reloc {
__u32 insn_off;
__u32 type_id;
__u32 access_str_off;
+ enum bpf_field_info_kind kind;
};
#endif /* __LIBBPF_LIBBPF_INTERNAL_H */
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-19 12:07:47 +0000