[ +Gustavo ]
On 8/17/22 3:05 AM, Dave Marchevsky wrote:
Commit 94dfc73e7cf4 ("treewide: uapi: Replace zero-length arrays with
flexible-array members") modified bpf_lpm_trie_key struct's data member
in include/uapi/linux/bpf.h, but didn't make the same change in tools
dir's copy. Propagate it over and fix comment indentation as well.
This is a nonfunctional change.
Signed-off-by: Dave Marchevsky <davemarchevsky@xxxxxx>
Gustavo, 94dfc73e7cf4 ("treewide: uapi: Replace zero-length arrays with flexible-array members")
breaks BPF when copied from include/uapi/linux/bpf.h to tools/include/uapi/linux/bpf.h :
CI: https://github.com/kernel-patches/bpf/runs/7885234999?check_suite_focus=true
[...]
CLNG-BPF [test_maps] map_ptr_kern.o
CLNG-BPF [test_maps] btf__core_reloc_arrays___diff_arr_val_sz.o
CLNG-BPF [test_maps] test_bpf_cookie.o
progs/map_ptr_kern.c:314:26: error: field 'trie_key' with variable sized type 'struct bpf_lpm_trie_key' not at the end of a struct or class is a GNU extension [-Werror,-Wgnu-variable-sized-type-not-at-end]
struct bpf_lpm_trie_key trie_key;
^
CLNG-BPF [test_maps] btf__core_reloc_type_based___diff.o
1 error generated.
make: *** [Makefile:521: /tmp/runner/work/bpf/bpf/tools/testing/selftests/bpf/map_ptr_kern.o] Error 1
make: *** Waiting for unfinished jobs....
If you look at the selftest tools/testing/selftests/bpf/progs/map_ptr_kern.c +314 :
/* Key of an a BPF_MAP_TYPE_LPM_TRIE entry */
struct bpf_lpm_trie_key {
__u32 prefixlen; /* up to 32 for AF_INET, 128 for AF_INET6 */
__u8 data[]; /* Arbitrary size */
};
struct lpm_key {
struct bpf_lpm_trie_key trie_key;
__u32 data;
};
Did you try to compile the tree (or selftests) with LLVM? I doubt the UX will be nice if everyone
now has to add -Wno-gnu-variable-sized-type-not-at-end ..
---
include/uapi/linux/bpf.h | 2 +-
tools/include/uapi/linux/bpf.h | 2 +-
2 files changed, 2 insertions(+), 2 deletions(-)
diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h
index 934a2a8beb87..0b09b5463afd 100644
--- a/include/uapi/linux/bpf.h
+++ b/include/uapi/linux/bpf.h
@@ -79,7 +79,7 @@ struct bpf_insn {
/* Key of an a BPF_MAP_TYPE_LPM_TRIE entry */
struct bpf_lpm_trie_key {
__u32 prefixlen; /* up to 32 for AF_INET, 128 for AF_INET6 */
- __u8 data[]; /* Arbitrary size */
+ __u8 data[]; /* Arbitrary size */
};
struct bpf_cgroup_storage_key {
diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h
index 1d6085e15fc8..0b09b5463afd 100644
--- a/tools/include/uapi/linux/bpf.h
+++ b/tools/include/uapi/linux/bpf.h
@@ -79,7 +79,7 @@ struct bpf_insn {
/* Key of an a BPF_MAP_TYPE_LPM_TRIE entry */
struct bpf_lpm_trie_key {
__u32 prefixlen; /* up to 32 for AF_INET, 128 for AF_INET6 */
- __u8 data[0]; /* Arbitrary size */
+ __u8 data[]; /* Arbitrary size */
};
struct bpf_cgroup_storage_key {
