Re: linux-next: build failure after merge of the bpf-next tree

On Tue, Sep 14, 2021 at 4:59 PM Stephen Rothwell [off-list ref] wrote:

Hi Andrii,

On Tue, 14 Sep 2021 16:40:37 -0700 Andrii Nakryiko [off-list ref] wrote:

quoted

On Tue, Sep 14, 2021 at 4:38 PM Stephen Rothwell [off-list ref] wrote:

quoted

Hi Andrii,

On Tue, 14 Sep 2021 16:25:55 -0700 Andrii Nakryiko [off-list ref] wrote:

quoted

On Mon, Sep 13, 2021 at 6:37 PM Stephen Rothwell [off-list ref] wrote:

quoted

After merging the bpf-next tree, today's linux-next build (perf) failed
like this:

util/bpf-event.c: In function 'btf__load_from_kernel_by_id':
util/bpf-event.c:27:8: error: 'btf__get_from_id' is deprecated: libbpf v0.6+: use btf__load_from_kernel_by_id instead [-Werror=deprecated-declarations]
   27 |        int err = btf__get_from_id(id, &btf);
      |        ^~~
In file included from util/bpf-event.c:5:
/home/sfr/next/next/tools/lib/bpf/btf.h:54:16: note: declared here
   54 | LIBBPF_API int btf__get_from_id(__u32 id, struct btf **btf);
      |                ^~~~~~~~~~~~~~~~
cc1: all warnings being treated as errors

Caused by commit

  0b46b7550560 ("libbpf: Add LIBBPF_DEPRECATED_SINCE macro for scheduling API deprecations")

Should be fixed by [0], when applied to perf tree. Thanks for reporting!

  [0] https://patchwork.kernel.org/project/netdevbpf/patch/20210914170004.4185659-1-andrii@kernel.org/

That really needs to be applied to the bpf-next tree (presumably with
the appropriate Acks).

This is perf code that's not in bpf-next yet.

Then you need to think of a solution for the bpf-next tree, as it will
not build (allmodconfig) when combined with Linus' current tree.  And
when it is merged into the net-next tree, that tree will be broken as
well.

It's not a problem of bpf-tree and it cannot be fixed in bpf-tree.
The bug is in perf tree.