From: Yonghong Song <yhs@fb.com>
Date: Thu, 21 Oct 2021 12:56:43 -0700
Subject: selftests/bpf: Add BTF_KIND_DECL_TAG typedef example in tag.c
Patch-mainline: v5.16-rc1
Git-commit: 8c18ea2d2c2913c80d8700c8bc8fe8568b8650a1
References: jsc#PED-1377
Change value type in progs/tag.c to a typedef with a btf_decl_tag.
With `bpftool btf dump file tag.o`, we have
...
[14] TYPEDEF 'value_t' type_id=17
[15] DECL_TAG 'tag1' type_id=14 component_idx=-1
[16] DECL_TAG 'tag2' type_id=14 component_idx=-1
[17] STRUCT '(anon)' size=8 vlen=2
'a' type_id=2 bits_offset=0
'b' type_id=2 bits_offset=32
...
The btf_tag selftest also succeeded:
$ ./test_progs -t tag
#21 btf_tag:OK
Summary: 1/0 PASSED, 0 SKIPPED, 0 FAILED
Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20211021195643.4020315-1-yhs@fb.com
Acked-by: Shung-Hsi Yu <shung-hsi.yu@suse.com>
---
tools/testing/selftests/bpf/progs/tag.c | 9 +++++++--
1 file changed, 7 insertions(+), 2 deletions(-)
--- a/tools/testing/selftests/bpf/progs/tag.c
+++ b/tools/testing/selftests/bpf/progs/tag.c
@@ -24,18 +24,23 @@ struct key_t {
int c;
} __tag1 __tag2;
+typedef struct {
+ int a;
+ int b;
+} value_t __tag1 __tag2;
+
struct {
__uint(type, BPF_MAP_TYPE_HASH);
__uint(max_entries, 3);
__type(key, struct key_t);
- __type(value, __u64);
+ __type(value, value_t);
} hashmap1 SEC(".maps");
static __noinline int foo(int x __tag1 __tag2) __tag1 __tag2
{
struct key_t key;
- __u64 val = 1;
+ value_t val = {};
key.a = key.b = key.c = x;
bpf_map_update_elem(&hashmap1, &key, &val, 0);