diff --git a/tools/bpf/bpftool/gen.c b/tools/bpf/bpftool/gen.c
index 51eaed76db97386eef9b22237c2ccf86debbc7d7..5a4d3240689ed0b1aa41bd32325d0dffecc33da8 100644
--- a/tools/bpf/bpftool/gen.c
+++ b/tools/bpf/bpftool/gen.c
@@ -852,24 +852,41 @@ codegen_maps_skeleton(struct bpf_object *obj, size_t map_cnt, bool mmaped, bool
{
struct bpf_map *map;
char ident[256];
- size_t i;
+ size_t i, map_sz;
if (!map_cnt)
return;
+ /* for backward compatibility with old libbpf versions that don't
+ * handle new BPF skeleton with new struct bpf_map_skeleton definition
+ * that includes link field, avoid specifying new increased size,
+ * unless we absolutely have to (i.e., if there are struct_ops maps
+ * present)
+ */
+ map_sz = offsetof(struct bpf_map_skeleton, link);
+ if (populate_links) {
+ bpf_object__for_each_map(map, obj) {
+ if (bpf_map__type(map) == BPF_MAP_TYPE_STRUCT_OPS) {
+ map_sz = sizeof(struct bpf_map_skeleton);
+ break;
+ }
+ }
+ }
+
codegen("\
\n\
- \n\
+ \n\
/* maps */ \n\
s->map_cnt = %zu; \n\
- s->map_skel_sz = sizeof(*s->maps); \n\
- s->maps = (struct bpf_map_skeleton *)calloc(s->map_cnt, s->map_skel_sz);\n\
+ s->map_skel_sz = %zu; \n\
+ s->maps = (struct bpf_map_skeleton *)calloc(s->map_cnt,\n\
+ sizeof(*s->maps) > %zu ? sizeof(*s->maps) : %zu);\n\
if (!s->maps) { \n\
err = -ENOMEM; \n\
goto err; \n\
} \n\
",
- map_cnt
+ map_cnt, map_sz, map_sz, map_sz
);
i = 0;
bpf_object__for_each_map(map, obj) {
@@ -878,23 +895,22 @@ codegen_maps_skeleton(struct bpf_object *obj, size_t map_cnt, bool mmaped, bool
codegen("\
\n\
- \n\
- s->maps[%zu].name = \"%s\"; \n\
- s->maps[%zu].map = &obj->maps.%s; \n\
+ \n\
+ map = (struct bpf_map_skeleton *)((char *)s->maps + %zu * s->map_skel_sz);\n\
+ map->name = \"%s\"; \n\
+ map->map = &obj->maps.%s; \n\
",
- i, bpf_map__name(map), i, ident);
+ i, bpf_map__name(map), ident);
/* memory-mapped internal maps */
if (mmaped && is_mmapable_map(map, ident, sizeof(ident))) {
- printf("\ts->maps[%zu].mmaped = (void **)&obj->%s;\n",
- i, ident);
+ printf("\tmap->mmaped = (void **)&obj->%s;\n", ident);
}
if (populate_links && bpf_map__type(map) == BPF_MAP_TYPE_STRUCT_OPS) {
codegen("\
\n\
- s->maps[%zu].link = &obj->links.%s;\n\
- ",
- i, ident);
+ map->link = &obj->links.%s; \n\
+ ", ident);
}
i++;
}
@@ -1463,6 +1479,7 @@ static int do_skeleton(int argc, char **argv)
%1$s__create_skeleton(struct %1$s *obj) \n\
{ \n\
struct bpf_object_skeleton *s; \n\
+ struct bpf_map_skeleton *map __attribute__((unused));\n\
int err; \n\
\n\
s = (struct bpf_object_skeleton *)calloc(1, sizeof(*s));\n\
@@ -1753,6 +1770,7 @@ static int do_subskeleton(int argc, char **argv)
{ \n\
struct %1$s *obj; \n\
struct bpf_object_subskeleton *s; \n\
+ struct bpf_map_skeleton *map __attribute__((unused));\n\
int err; \n\
\n\
obj = (struct %1$s *)calloc(1, sizeof(*obj)); \n\
diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index 30f121754d831a800daeddbee3a968d64ff5578c..a3be6f8fac09ea25983f3619c5094c5dde9ef4ae 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -13712,14 +13712,15 @@ int libbpf_num_possible_cpus(void)
static int populate_skeleton_maps(const struct bpf_object *obj,
struct bpf_map_skeleton *maps,
- size_t map_cnt)
+ size_t map_cnt, size_t map_skel_sz)
{
int i;
for (i = 0; i < map_cnt; i++) {
- struct bpf_map **map = maps[i].map;
- const char *name = maps[i].name;
- void **mmaped = maps[i].mmaped;
+ struct bpf_map_skeleton *map_skel = (void *)maps + i * map_skel_sz;
+ struct bpf_map **map = map_skel->map;
+ const char *name = map_skel->name;
+ void **mmaped = map_skel->mmaped;
*map = bpf_object__find_map_by_name(obj, name);
if (!*map) {
@@ -13736,13 +13737,14 @@ static int populate_skeleton_maps(const struct bpf_object *obj,
static int populate_skeleton_progs(const struct bpf_object *obj,
struct bpf_prog_skeleton *progs,
- size_t prog_cnt)
+ size_t prog_cnt, size_t prog_skel_sz)
{
int i;
for (i = 0; i < prog_cnt; i++) {
- struct bpf_program **prog = progs[i].prog;
- const char *name = progs[i].name;
+ struct bpf_prog_skeleton *prog_skel = (void *)progs + i * prog_skel_sz;
+ struct bpf_program **prog = prog_skel->prog;
+ const char *name = prog_skel->name;
*prog = bpf_object__find_program_by_name(obj, name);
if (!*prog) {
@@ -13783,13 +13785,13 @@ int bpf_object__open_skeleton(struct bpf_object_skeleton *s,
}
*s->obj = obj;
- err = populate_skeleton_maps(obj, s->maps, s->map_cnt);
+ err = populate_skeleton_maps(obj, s->maps, s->map_cnt, s->map_skel_sz);
if (err) {
pr_warn("failed to populate skeleton maps for '%s': %d\n", s->name, err);
return libbpf_err(err);
}
- err = populate_skeleton_progs(obj, s->progs, s->prog_cnt);
+ err = populate_skeleton_progs(obj, s->progs, s->prog_cnt, s->prog_skel_sz);
if (err) {
pr_warn("failed to populate skeleton progs for '%s': %d\n", s->name, err);
return libbpf_err(err);
@@ -13819,20 +13821,20 @@ int bpf_object__open_subskeleton(struct bpf_object_subskeleton *s)
return libbpf_err(-errno);
}
- err = populate_skeleton_maps(s->obj, s->maps, s->map_cnt);
+ err = populate_skeleton_maps(s->obj, s->maps, s->map_cnt, s->map_skel_sz);
if (err) {
pr_warn("failed to populate subskeleton maps: %d\n", err);
return libbpf_err(err);
}
- err = populate_skeleton_progs(s->obj, s->progs, s->prog_cnt);
+ err = populate_skeleton_progs(s->obj, s->progs, s->prog_cnt, s->prog_skel_sz);
if (err) {
pr_warn("failed to populate subskeleton maps: %d\n", err);
return libbpf_err(err);
}
for (var_idx = 0; var_idx < s->var_cnt; var_idx++) {
- var_skel = &s->vars[var_idx];
+ var_skel = (void *)s->vars + var_idx * s->var_skel_sz;
map = *var_skel->map;
map_type_id = bpf_map__btf_value_type_id(map);
map_type = btf__type_by_id(btf, map_type_id);
@@ -13879,10 +13881,11 @@ int bpf_object__load_skeleton(struct bpf_object_skeleton *s)
}
for (i = 0; i < s->map_cnt; i++) {
- struct bpf_map *map = *s->maps[i].map;
+ struct bpf_map_skeleton *map_skel = (void *)s->maps + i * s->map_skel_sz;
+ struct bpf_map *map = *map_skel->map;
size_t mmap_sz = bpf_map_mmap_sz(map);
int prot, map_fd = map->fd;
- void **mmaped = s->maps[i].mmaped;
+ void **mmaped = map_skel->mmaped;
if (!mmaped)
continue;
@@ -13930,8 +13933,9 @@ int bpf_object__attach_skeleton(struct bpf_object_skeleton *s)
int i, err;
for (i = 0; i < s->prog_cnt; i++) {
- struct bpf_program *prog = *s->progs[i].prog;
- struct bpf_link **link = s->progs[i].link;
+ struct bpf_prog_skeleton *prog_skel = (void *)s->progs + i * s->prog_skel_sz;
+ struct bpf_program *prog = *prog_skel->prog;
+ struct bpf_link **link = prog_skel->link;
if (!prog->autoload || !prog->autoattach)
continue;
@@ -13963,31 +13967,34 @@ int bpf_object__attach_skeleton(struct bpf_object_skeleton *s)
*/
}
- /* Skeleton is created with earlier version of bpftool
- * which does not support auto-attachment
- */
- if (s->map_skel_sz < sizeof(struct bpf_map_skeleton))
- return 0;
for (i = 0; i < s->map_cnt; i++) {
- struct bpf_map *map = *s->maps[i].map;
- struct bpf_link **link = s->maps[i].link;
+ struct bpf_map_skeleton *map_skel = (void *)s->maps + i * s->map_skel_sz;
+ struct bpf_map *map = *map_skel->map;
+ struct bpf_link **link;
if (!map->autocreate || !map->autoattach)
continue;
- if (*link)
- continue;
-
/* only struct_ops maps can be attached */
if (!bpf_map__is_struct_ops(map))
continue;
- *link = bpf_map__attach_struct_ops(map);
+ /* skeleton is created with earlier version of bpftool, notify user */
+ if (s->map_skel_sz < offsetofend(struct bpf_map_skeleton, link)) {
+ pr_warn("map '%s': BPF skeleton version is old, skipping map auto-attachment...\n",
+ bpf_map__name(map));
+ continue;
+ }
+
+ link = map_skel->link;
+ if (*link)
+ continue;
+
+ *link = bpf_map__attach_struct_ops(map);
if (!*link) {
err = -errno;
- pr_warn("map '%s': failed to auto-attach: %d\n",
- bpf_map__name(map), err);
+ pr_warn("map '%s': failed to auto-attach: %d\n", bpf_map__name(map), err);
return libbpf_err(err);
}
}
@@ -14000,7 +14007,8 @@ void bpf_object__detach_skeleton(struct bpf_object_skeleton *s)
int i;
for (i = 0; i < s->prog_cnt; i++) {
- struct bpf_link **link = s->progs[i].link;
+ struct bpf_prog_skeleton *prog_skel = (void *)s->progs + i * s->prog_skel_sz;
+ struct bpf_link **link = prog_skel->link;
bpf_link__destroy(*link);
*link = NULL;
@@ -14010,7 +14018,8 @@ void bpf_object__detach_skeleton(struct bpf_object_skeleton *s)
return;
for (i = 0; i < s->map_cnt; i++) {
- struct bpf_link **link = s->maps[i].link;
+ struct bpf_map_skeleton *map_skel = (void *)s->maps + i * s->map_skel_sz;
+ struct bpf_link **link = map_skel->link;
if (link) {
bpf_link__destroy(*link);