| Message ID | 20220222074524.1027060-2-xukuohai@huawei.com (mailing list archive) |
|---|---|
| State | Changes Requested |
| Delegated to: | BPF |
| Headers | show |
| Series | libbpf: Fix btf dump error for BTF_KIND_FWD | expand |
On Mon, Feb 21, 2022 at 11:41 PM Xu Kuohai <xukuohai@huawei.com> wrote: > > If a FWD appears in the BTF before a STRUCT with the same name, the > STRUCT is dumped with a conflicted name: > > $ bpftool btf dump file vmlinux format raw | grep "'unix_sock'" > [81287] FWD 'unix_sock' fwd_kind=struct > [89336] STRUCT 'unix_sock' size=1024 vlen=14 > > $ bpftool btf dump file vmlinux format c | grep "struct unix_sock" > struct unix_sock; > struct unix_sock___2 { <--- conflict, the "___2" is unexpected > struct unix_sock___2 *unix_sk; > > Fixes: 351131b51c7a ("libbpf: add btf_dump API for BTF-to-C conversion") > Signed-off-by: Xu Kuohai <xukuohai@huawei.com> Acked-by: Song Liu <songliubraving@fb.com>
On Mon, Feb 21, 2022 at 11:34 PM Xu Kuohai <xukuohai@huawei.com> wrote: > > If a FWD appears in the BTF before a STRUCT with the same name, the > STRUCT is dumped with a conflicted name: > > $ bpftool btf dump file vmlinux format raw | grep "'unix_sock'" > [81287] FWD 'unix_sock' fwd_kind=struct > [89336] STRUCT 'unix_sock' size=1024 vlen=14 > > $ bpftool btf dump file vmlinux format c | grep "struct unix_sock" > struct unix_sock; > struct unix_sock___2 { <--- conflict, the "___2" is unexpected > struct unix_sock___2 *unix_sk; > > Fixes: 351131b51c7a ("libbpf: add btf_dump API for BTF-to-C conversion") > Signed-off-by: Xu Kuohai <xukuohai@huawei.com> > --- > tools/lib/bpf/btf_dump.c | 16 +++++++++------- > 1 file changed, 9 insertions(+), 7 deletions(-) > > diff --git a/tools/lib/bpf/btf_dump.c b/tools/lib/bpf/btf_dump.c > index 07ebe70d3a30..55079efbd8f1 100644 > --- a/tools/lib/bpf/btf_dump.c > +++ b/tools/lib/bpf/btf_dump.c > @@ -1505,13 +1505,15 @@ static const char *btf_dump_resolve_name(struct btf_dump *d, __u32 id, > if (s->name_resolved) > return *cached_name ? *cached_name : orig_name; > > - dup_cnt = btf_dump_name_dups(d, name_map, orig_name); > - if (dup_cnt > 1) { > - const size_t max_len = 256; > - char new_name[max_len]; > - > - snprintf(new_name, max_len, "%s___%zu", orig_name, dup_cnt); > - *cached_name = strdup(new_name); > + if (!btf_is_fwd(t)) { let's handle FWD as a special case and not touch existing logic. Maybe something like this? if (btf_is_fwd(t) || (btf_is_enum(t) && btf_vlen(t) == 0)) { s->name_resolved = 1; return orig_name; } btf_is_enum() part should handle enum forward declarations (they are represented as enums with no values defined) > + dup_cnt = btf_dump_name_dups(d, name_map, orig_name); > + if (dup_cnt > 1) { > + const size_t max_len = 256; > + char new_name[max_len]; > + > + snprintf(new_name, max_len, "%s___%zu", orig_name, dup_cnt); > + *cached_name = strdup(new_name); > + } > } > > s->name_resolved = 1; > -- > 2.30.2 >
diff --git a/tools/lib/bpf/btf_dump.c b/tools/lib/bpf/btf_dump.c index 07ebe70d3a30..55079efbd8f1 100644 --- a/tools/lib/bpf/btf_dump.c +++ b/tools/lib/bpf/btf_dump.c @@ -1505,13 +1505,15 @@ static const char *btf_dump_resolve_name(struct btf_dump *d, __u32 id, if (s->name_resolved) return *cached_name ? *cached_name : orig_name; - dup_cnt = btf_dump_name_dups(d, name_map, orig_name); - if (dup_cnt > 1) { - const size_t max_len = 256; - char new_name[max_len]; - - snprintf(new_name, max_len, "%s___%zu", orig_name, dup_cnt); - *cached_name = strdup(new_name); + if (!btf_is_fwd(t)) { + dup_cnt = btf_dump_name_dups(d, name_map, orig_name); + if (dup_cnt > 1) { + const size_t max_len = 256; + char new_name[max_len]; + + snprintf(new_name, max_len, "%s___%zu", orig_name, dup_cnt); + *cached_name = strdup(new_name); + } } s->name_resolved = 1;
If a FWD appears in the BTF before a STRUCT with the same name, the STRUCT is dumped with a conflicted name: $ bpftool btf dump file vmlinux format raw | grep "'unix_sock'" [81287] FWD 'unix_sock' fwd_kind=struct [89336] STRUCT 'unix_sock' size=1024 vlen=14 $ bpftool btf dump file vmlinux format c | grep "struct unix_sock" struct unix_sock; struct unix_sock___2 { <--- conflict, the "___2" is unexpected struct unix_sock___2 *unix_sk; Fixes: 351131b51c7a ("libbpf: add btf_dump API for BTF-to-C conversion") Signed-off-by: Xu Kuohai <xukuohai@huawei.com> --- tools/lib/bpf/btf_dump.c | 16 +++++++++------- 1 file changed, 9 insertions(+), 7 deletions(-)