Use less verbose names in BTF relocation code and fix off-by-one error
and typo in btf_relocate.c. Simplify loop over matching distilled
types, moving from assigning a _next value in loop body to moving
match check conditions into the guard.
Suggested-by: Andrii Nakryiko <andrii.nakryiko@xxxxxxxxx>
Signed-off-by: Alan Maguire <alan.maguire@xxxxxxxxxx>
Acked-by: Eduard Zingerman <eddyz87@xxxxxxxxx>
---
tools/lib/bpf/btf_relocate.c | 72 ++++++++++++++++--------------------
1 file changed, 31 insertions(+), 41 deletions(-)
diff --git a/tools/lib/bpf/btf_relocate.c b/tools/lib/bpf/btf_relocate.c
index eabb8755f662..23a41fb03e0d 100644
--- a/tools/lib/bpf/btf_relocate.c
+++ b/tools/lib/bpf/btf_relocate.c
@@ -160,7 +160,7 @@ static int btf_mark_embedded_composite_type_ids(struct btf_relocate *r, __u32 i)
*/
static int btf_relocate_map_distilled_base(struct btf_relocate *r)
{
- struct btf_name_info *dist_base_info_sorted, *dist_base_info_sorted_end;
+ struct btf_name_info *info, *info_end;
struct btf_type *base_t, *dist_t;
__u8 *base_name_cnt = NULL;
int err = 0;
@@ -169,26 +169,24 @@ static int btf_relocate_map_distilled_base(struct btf_relocate *r)
/* generate a sort index array of name/type ids sorted by name for
* distilled base BTF to speed name-based lookups.
*/
- dist_base_info_sorted = calloc(r->nr_dist_base_types, sizeof(*dist_base_info_sorted));
- if (!dist_base_info_sorted) {
+ info = calloc(r->nr_dist_base_types, sizeof(*info));
+ if (!info) {
err = -ENOMEM;
goto done;
}
- dist_base_info_sorted_end = dist_base_info_sorted + r->nr_dist_base_types;
+ info_end = info + r->nr_dist_base_types;
for (id = 0; id < r->nr_dist_base_types; id++) {
dist_t = btf_type_by_id(r->dist_base_btf, id);
- dist_base_info_sorted[id].name = btf__name_by_offset(r->dist_base_btf,
- dist_t->name_off);
- dist_base_info_sorted[id].id = id;
- dist_base_info_sorted[id].size = dist_t->size;
- dist_base_info_sorted[id].needs_size = true;
+ info[id].name = btf__name_by_offset(r->dist_base_btf, dist_t->name_off);
+ info[id].id = id;
+ info[id].size = dist_t->size;
+ info[id].needs_size = true;
}
- qsort(dist_base_info_sorted, r->nr_dist_base_types, sizeof(*dist_base_info_sorted),
- cmp_btf_name_size);
+ qsort(info, r->nr_dist_base_types, sizeof(*info), cmp_btf_name_size);
/* Mark distilled base struct/union members of split BTF structs/unions
* in id_map with BTF_IS_EMBEDDED; this signals that these types
- * need to match both name and size, otherwise embeddding the base
+ * need to match both name and size, otherwise embedding the base
* struct/union in the split type is invalid.
*/
for (id = r->nr_dist_base_types; id < r->nr_split_types; id++) {
@@ -216,8 +214,7 @@ static int btf_relocate_map_distilled_base(struct btf_relocate *r)
/* Now search base BTF for matching distilled base BTF types. */
for (id = 1; id < r->nr_base_types; id++) {
- struct btf_name_info *dist_name_info, *dist_name_info_next = NULL;
- struct btf_name_info base_name_info = {};
+ struct btf_name_info *dist_info, base_info = {};
int dist_kind, base_kind;
base_t = btf_type_by_id(r->base_btf, id);
@@ -225,16 +222,16 @@ static int btf_relocate_map_distilled_base(struct btf_relocate *r)
if (!base_t->name_off)
continue;
base_kind = btf_kind(base_t);
- base_name_info.id = id;
- base_name_info.name = btf__name_by_offset(r->base_btf, base_t->name_off);
+ base_info.id = id;
+ base_info.name = btf__name_by_offset(r->base_btf, base_t->name_off);
switch (base_kind) {
case BTF_KIND_INT:
case BTF_KIND_FLOAT:
case BTF_KIND_ENUM:
case BTF_KIND_ENUM64:
/* These types should match both name and size */
- base_name_info.needs_size = true;
- base_name_info.size = base_t->size;
+ base_info.needs_size = true;
+ base_info.size = base_t->size;
break;
case BTF_KIND_FWD:
/* No size considerations for fwds. */
@@ -248,31 +245,24 @@ static int btf_relocate_map_distilled_base(struct btf_relocate *r)
* unless corresponding _base_ types to match them are
* missing.
*/
- base_name_info.needs_size = base_name_cnt[base_t->name_off] > 1;
- base_name_info.size = base_t->size;
+ base_info.needs_size = base_name_cnt[base_t->name_off] > 1;
+ base_info.size = base_t->size;
break;
default:
continue;
}
/* iterate over all matching distilled base types */
- for (dist_name_info = search_btf_name_size(&base_name_info, dist_base_info_sorted,
- r->nr_dist_base_types);
- dist_name_info != NULL; dist_name_info = dist_name_info_next) {
- /* Are there more distilled matches to process after
- * this one?
- */
- dist_name_info_next = dist_name_info + 1;
- if (dist_name_info_next >= dist_base_info_sorted_end ||
- cmp_btf_name_size(&base_name_info, dist_name_info_next))
- dist_name_info_next = NULL;
-
- if (!dist_name_info->id || dist_name_info->id > r->nr_dist_base_types) {
+ for (dist_info = search_btf_name_size(&base_info, info, r->nr_dist_base_types);
+ dist_info != NULL && dist_info < info_end &&
+ cmp_btf_name_size(&base_info, dist_info) == 0;
+ dist_info++) {
+ if (!dist_info->id || dist_info->id >= r->nr_dist_base_types) {
pr_warn("base BTF id [%d] maps to invalid distilled base BTF id [%d]\n",
- id, dist_name_info->id);
+ id, dist_info->id);
err = -EINVAL;
goto done;
}
- dist_t = btf_type_by_id(r->dist_base_btf, dist_name_info->id);
+ dist_t = btf_type_by_id(r->dist_base_btf, dist_info->id);
dist_kind = btf_kind(dist_t);
/* Validate that the found distilled type is compatible.
@@ -319,15 +309,15 @@ static int btf_relocate_map_distilled_base(struct btf_relocate *r)
/* size verification is required for embedded
* struct/unions.
*/
- if (r->id_map[dist_name_info->id] == BTF_IS_EMBEDDED &&
+ if (r->id_map[dist_info->id] == BTF_IS_EMBEDDED &&
base_t->size != dist_t->size)
continue;
break;
default:
continue;
}
- if (r->id_map[dist_name_info->id] &&
- r->id_map[dist_name_info->id] != BTF_IS_EMBEDDED) {
+ if (r->id_map[dist_info->id] &&
+ r->id_map[dist_info->id] != BTF_IS_EMBEDDED) {
/* we already have a match; this tells us that
* multiple base types of the same name
* have the same size, since for cases where
@@ -337,13 +327,13 @@ static int btf_relocate_map_distilled_base(struct btf_relocate *r)
* to in base BTF, so error out.
*/
pr_warn("distilled base BTF type '%s' [%u], size %u has multiple candidates of the same size (ids [%u, %u]) in base BTF\n",
- base_name_info.name, dist_name_info->id,
- base_t->size, id, r->id_map[dist_name_info->id]);
+ base_info.name, dist_info->id,
+ base_t->size, id, r->id_map[dist_info->id]);
err = -EINVAL;
goto done;
}
/* map id and name */
- r->id_map[dist_name_info->id] = id;
+ r->id_map[dist_info->id] = id;
r->str_map[dist_t->name_off] = base_t->name_off;
}
}
@@ -362,7 +352,7 @@ static int btf_relocate_map_distilled_base(struct btf_relocate *r)
}
done:
free(base_name_cnt);
- free(dist_base_info_sorted);
+ free(info);
return err;
}
--
2.31.1
