Switch all BPF linker code dealing with iterating BTF type ID and string
offset fields to new btf_field_iter facilities.
Acked-by: Eduard Zingerman <eddyz87@xxxxxxxxx>
Acked-by: Jiri Olsa <jolsa@xxxxxxxxxx>
Signed-off-by: Andrii Nakryiko <andrii@xxxxxxxxxx>
---
tools/lib/bpf/btf.c | 4 +--
tools/lib/bpf/libbpf_internal.h | 4 +--
tools/lib/bpf/linker.c | 58 ++++++++++++++++++++-------------
3 files changed, 40 insertions(+), 26 deletions(-)
diff --git a/tools/lib/bpf/btf.c b/tools/lib/bpf/btf.c
index 50ff8b6eaf36..d72260ac26a5 100644
--- a/tools/lib/bpf/btf.c
+++ b/tools/lib/bpf/btf.c
@@ -5267,7 +5267,7 @@ __u32 *btf_field_iter_next(struct btf_field_iter *it)
return NULL;
if (it->m_idx < 0) {
- if (it->off_idx < it->desc.t_cnt)
+ if (it->off_idx < it->desc.t_off_cnt)
return it->p + it->desc.t_offs[it->off_idx++];
/* move to per-member iteration */
it->m_idx = 0;
@@ -5281,7 +5281,7 @@ __u32 *btf_field_iter_next(struct btf_field_iter *it)
return NULL;
}
- if (it->off_idx >= it->desc.m_cnt) {
+ if (it->off_idx >= it->desc.m_off_cnt) {
/* exhausted this member's fields, go to the next member */
it->m_idx++;
it->p += it->desc.m_sz;
diff --git a/tools/lib/bpf/libbpf_internal.h b/tools/lib/bpf/libbpf_internal.h
index 80f3d346db33..96c0b0993f8b 100644
--- a/tools/lib/bpf/libbpf_internal.h
+++ b/tools/lib/bpf/libbpf_internal.h
@@ -515,11 +515,11 @@ enum btf_field_iter_kind {
struct btf_field_desc {
/* once-per-type offsets */
- int t_cnt, t_offs[2];
+ int t_off_cnt, t_offs[2];
/* member struct size, or zero, if no members */
int m_sz;
/* repeated per-member offsets */
- int m_cnt, m_offs[1];
+ int m_off_cnt, m_offs[1];
};
struct btf_field_iter {
diff --git a/tools/lib/bpf/linker.c b/tools/lib/bpf/linker.c
index 0d4be829551b..fa11a671da3e 100644
--- a/tools/lib/bpf/linker.c
+++ b/tools/lib/bpf/linker.c
@@ -957,19 +957,33 @@ static int check_btf_str_off(__u32 *str_off, void *ctx)
static int linker_sanity_check_btf(struct src_obj *obj)
{
struct btf_type *t;
- int i, n, err = 0;
+ int i, n, err;
if (!obj->btf)
return 0;
n = btf__type_cnt(obj->btf);
for (i = 1; i < n; i++) {
+ struct btf_field_iter it;
+ __u32 *type_id, *str_off;
+
t = btf_type_by_id(obj->btf, i);
- err = err ?: btf_type_visit_type_ids(t, check_btf_type_id, obj->btf);
- err = err ?: btf_type_visit_str_offs(t, check_btf_str_off, obj->btf);
+ err = btf_field_iter_init(&it, t, BTF_FIELD_ITER_IDS);
if (err)
return err;
+ while ((type_id = btf_field_iter_next(&it))) {
+ if (*type_id >= n)
+ return -EINVAL;
+ }
+
+ err = btf_field_iter_init(&it, t, BTF_FIELD_ITER_STRS);
+ if (err)
+ return err;
+ while ((str_off = btf_field_iter_next(&it))) {
+ if (!btf__str_by_offset(obj->btf, *str_off))
+ return -EINVAL;
+ }
}
return 0;
@@ -2234,26 +2248,10 @@ static int linker_fixup_btf(struct src_obj *obj)
return 0;
}
-static int remap_type_id(__u32 *type_id, void *ctx)
-{
- int *id_map = ctx;
- int new_id = id_map[*type_id];
-
- /* Error out if the type wasn't remapped. Ignore VOID which stays VOID. */
- if (new_id == 0 && *type_id != 0) {
- pr_warn("failed to find new ID mapping for original BTF type ID %u\n", *type_id);
- return -EINVAL;
- }
-
- *type_id = id_map[*type_id];
-
- return 0;
-}
-
static int linker_append_btf(struct bpf_linker *linker, struct src_obj *obj)
{
const struct btf_type *t;
- int i, j, n, start_id, id;
+ int i, j, n, start_id, id, err;
const char *name;
if (!obj->btf)
@@ -2324,9 +2322,25 @@ static int linker_append_btf(struct bpf_linker *linker, struct src_obj *obj)
n = btf__type_cnt(linker->btf);
for (i = start_id; i < n; i++) {
struct btf_type *dst_t = btf_type_by_id(linker->btf, i);
+ struct btf_field_iter it;
+ __u32 *type_id;
- if (btf_type_visit_type_ids(dst_t, remap_type_id, obj->btf_type_map))
- return -EINVAL;
+ err = btf_field_iter_init(&it, dst_t, BTF_FIELD_ITER_IDS);
+ if (err)
+ return err;
+
+ while ((type_id = btf_field_iter_next(&it))) {
+ int new_id = obj->btf_type_map[*type_id];
+
+ /* Error out if the type wasn't remapped. Ignore VOID which stays VOID. */
+ if (new_id == 0 && *type_id != 0) {
+ pr_warn("failed to find new ID mapping for original BTF type ID %u\n",
+ *type_id);
+ return -EINVAL;
+ }
+
+ *type_id = obj->btf_type_map[*type_id];
+ }
}
/* Rewrite VAR/FUNC underlying types (i.e., FUNC's FUNC_PROTO and VAR's
--
2.43.0
