From: Delyan Kratunov <delyank@fb.com>
Date: Wed, 16 Mar 2022 23:37:30 +0000
Subject: libbpf: Init btf_{key,value}_type_id on internal map open
Patch-mainline: v5.18-rc1
Git-commit: 262cfb74ffdaed06e65b8b20e10241768a9a2e18
References: jsc#PED-1377
For internal and user maps, look up the key and value btf
types on open() and not load(), so that `bpf_map_btf_value_type_id`
is usable in `bpftool gen`.
Signed-off-by: Delyan Kratunov <delyank@fb.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/78dbe4e457b4a05e098fc6c8f50014b680c86e4e.1647473511.git.delyank@fb.com
Acked-by: Shung-Hsi Yu <shung-hsi.yu@suse.com>
---
tools/lib/bpf/libbpf.c | 15 ++++++++++++++-
1 file changed, 14 insertions(+), 1 deletion(-)
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -1518,6 +1518,9 @@ static char *internal_map_name(struct bp
}
static int
+bpf_map_find_btf_info(struct bpf_object *obj, struct bpf_map *map);
+
+static int
bpf_object__init_internal_map(struct bpf_object *obj, enum libbpf_map_type type,
const char *real_name, int sec_idx, void *data, size_t data_sz)
{
@@ -1564,6 +1567,9 @@ bpf_object__init_internal_map(struct bpf
return err;
}
+ /* failures are fine because of maps like .rodata.str1.1 */
+ (void) bpf_map_find_btf_info(obj, map);
+
if (data)
memcpy(map->mmaped, data, data_sz);
@@ -2046,6 +2052,9 @@ static int bpf_object__init_user_maps(st
}
memcpy(&map->def, def, sizeof(struct bpf_map_def));
}
+
+ /* btf info may not exist but fill it in if it does exist */
+ (void) bpf_map_find_btf_info(obj, map);
}
return 0;
}
@@ -2534,6 +2543,10 @@ static int bpf_object__init_user_btf_map
fill_map_from_def(map->inner_map, &inner_def);
}
+ err = bpf_map_find_btf_info(obj, map);
+ if (err)
+ return err;
+
return 0;
}
@@ -4873,7 +4886,7 @@ static int bpf_object__create_map(struct
if (bpf_map__is_struct_ops(map))
create_attr.btf_vmlinux_value_type_id = map->btf_vmlinux_value_type_id;
- if (obj->btf && btf__fd(obj->btf) >= 0 && !bpf_map_find_btf_info(obj, map)) {
+ if (obj->btf && btf__fd(obj->btf) >= 0) {
create_attr.btf_fd = btf__fd(obj->btf);
create_attr.btf_key_type_id = map->btf_key_type_id;
create_attr.btf_value_type_id = map->btf_value_type_id;