| Message ID | 20230810183513.684836-2-davemarchevsky@fb.com (mailing list archive) |
|---|---|
| State | Superseded |
| Delegated to: | BPF |
| Headers | show |
| Series | Open-coded task_vma iter | expand |
On 8/10/23 11:35 AM, Dave Marchevsky wrote: > Commit 6018e1f407cc ("bpf: implement numbers iterator") added the > BTF_TYPE_EMIT line that this patch is modifying. The struct btf_iter_num > doesn't exist, so only a forward declaration is emitted in BTF: > > FWD 'btf_iter_num' fwd_kind=struct > > Since that commit was probably hoping to ensure that struct bpf_iter_num > is emitted in vmlinux BTF, this patch changes it to the correct type. > > This isn't marked "Fixes" because the extraneous btf_iter_num FWD wasn't > causing any issues that I noticed, aside from mild confusion when I > looked through the code. > > Signed-off-by: Dave Marchevsky <davemarchevsky@fb.com> > --- > kernel/bpf/bpf_iter.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/kernel/bpf/bpf_iter.c b/kernel/bpf/bpf_iter.c > index 96856f130cbf..20ef64445754 100644 > --- a/kernel/bpf/bpf_iter.c > +++ b/kernel/bpf/bpf_iter.c > @@ -793,7 +793,7 @@ __bpf_kfunc int bpf_iter_num_new(struct bpf_iter_num *it, int start, int end) > BUILD_BUG_ON(sizeof(struct bpf_iter_num_kern) != sizeof(struct bpf_iter_num)); > BUILD_BUG_ON(__alignof__(struct bpf_iter_num_kern) != __alignof__(struct bpf_iter_num)); > > - BTF_TYPE_EMIT(struct btf_iter_num); > + BTF_TYPE_EMIT(struct bpf_iter_num); I think this can be removed instead. In kernel/bpf/bpf_iter.c, we have __bpf_kfunc int bpf_iter_num_new(struct bpf_iter_num *it, int start, int end) __bpf_kfunc int *bpf_iter_num_next(struct bpf_iter_num* it) __bpf_kfunc void bpf_iter_num_destroy(struct bpf_iter_num *it) This will ensure that bpf_iter_num btf type will be generated by the compiler. > > /* start == end is legit, it's an empty range and we'll just get NULL > * on first (and any subsequent) bpf_iter_num_next() call
diff --git a/kernel/bpf/bpf_iter.c b/kernel/bpf/bpf_iter.c index 96856f130cbf..20ef64445754 100644 --- a/kernel/bpf/bpf_iter.c +++ b/kernel/bpf/bpf_iter.c @@ -793,7 +793,7 @@ __bpf_kfunc int bpf_iter_num_new(struct bpf_iter_num *it, int start, int end) BUILD_BUG_ON(sizeof(struct bpf_iter_num_kern) != sizeof(struct bpf_iter_num)); BUILD_BUG_ON(__alignof__(struct bpf_iter_num_kern) != __alignof__(struct bpf_iter_num)); - BTF_TYPE_EMIT(struct btf_iter_num); + BTF_TYPE_EMIT(struct bpf_iter_num); /* start == end is legit, it's an empty range and we'll just get NULL * on first (and any subsequent) bpf_iter_num_next() call
Commit 6018e1f407cc ("bpf: implement numbers iterator") added the BTF_TYPE_EMIT line that this patch is modifying. The struct btf_iter_num doesn't exist, so only a forward declaration is emitted in BTF: FWD 'btf_iter_num' fwd_kind=struct Since that commit was probably hoping to ensure that struct bpf_iter_num is emitted in vmlinux BTF, this patch changes it to the correct type. This isn't marked "Fixes" because the extraneous btf_iter_num FWD wasn't causing any issues that I noticed, aside from mild confusion when I looked through the code. Signed-off-by: Dave Marchevsky <davemarchevsky@fb.com> --- kernel/bpf/bpf_iter.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)