Allow using two new section names for struct_ops maps:
- SEC("?.struct_ops")
- SEC("?.struct_ops.link")
To specify maps that have bpf_map->autocreate == false after open.
Signed-off-by: Eduard Zingerman <eddyz87@xxxxxxxxx>
---
tools/lib/bpf/libbpf.c | 17 ++++++++++++++++-
1 file changed, 16 insertions(+), 1 deletion(-)
diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index 8ecfad091cb5..157d28aea186 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -497,6 +497,8 @@ struct bpf_struct_ops {
#define KSYMS_SEC ".ksyms"
#define STRUCT_OPS_SEC ".struct_ops"
#define STRUCT_OPS_LINK_SEC ".struct_ops.link"
+#define OPT_STRUCT_OPS_SEC "?.struct_ops"
+#define OPT_STRUCT_OPS_LINK_SEC "?.struct_ops.link"
enum libbpf_map_type {
LIBBPF_MAP_UNSPEC,
@@ -1278,6 +1280,15 @@ static int init_struct_ops_maps(struct bpf_object *obj, const char *sec_name,
return -ENOMEM;
map->btf_value_type_id = type_id;
+ /* Follow same convention as for programs autoload:
+ * SEC("?.struct_ops") means map is not created by default.
+ */
+ if (sec_name[0] == '?') {
+ map->autocreate = false;
+ /* from now on forget there was ? in section name */
+ sec_name++;
+ }
+
map->def.type = BPF_MAP_TYPE_STRUCT_OPS;
map->def.key_size = sizeof(int);
map->def.value_size = type->size;
@@ -3647,7 +3658,9 @@ static int bpf_object__elf_collect(struct bpf_object *obj)
sec_desc->shdr = sh;
sec_desc->data = data;
} else if (strcmp(name, STRUCT_OPS_SEC) == 0 ||
- strcmp(name, STRUCT_OPS_LINK_SEC) == 0) {
+ strcmp(name, STRUCT_OPS_LINK_SEC) == 0 ||
+ strcmp(name, OPT_STRUCT_OPS_SEC) == 0 ||
+ strcmp(name, OPT_STRUCT_OPS_LINK_SEC) == 0) {
sec_desc->sec_type = SEC_ST_OPS;
sec_desc->shdr = sh;
sec_desc->data = data;
@@ -3667,6 +3680,8 @@ static int bpf_object__elf_collect(struct bpf_object *obj)
if (!section_have_execinstr(obj, targ_sec_idx) &&
strcmp(name, ".rel" STRUCT_OPS_SEC) &&
strcmp(name, ".rel" STRUCT_OPS_LINK_SEC) &&
+ strcmp(name, ".rel" OPT_STRUCT_OPS_SEC) &&
+ strcmp(name, ".rel" OPT_STRUCT_OPS_LINK_SEC) &&
strcmp(name, ".rel" MAPS_ELF_SEC)) {
pr_info("elf: skipping relo section(%d) %s for section(%d) %s\n",
idx, name, targ_sec_idx,
--
2.43.0
