On Thu, Sep 30, 2021 at 09:59:32AM +1000, Stephen Rothwell wrote:

Hi all,

After merging the kspp-gustavo tree, today's linux-next build (x86_64
allmodconfig) failed like this:

In file included from include/linux/bpf_verifier.h:9,
                 from kernel/bpf/verifier.c:12:

[..]

      |                 ^~~~~~~~~~~~~
include/linux/filter.h:366:4: error: cast between incompatible function types from 'int (* const)(struct bpf_map *, u32,  u64)' {aka 'int (* const)(struct bpf_map *, unsigned int,  long long unsigned int)'} to 'u64 (*)(u64,  u64,  u64,  u64,  u64)' {aka 'long long unsigned int (*)(long long unsigned int,  long long unsigned int,  long long unsigned int,  long long unsigned int,  long long unsigned int)'} [-Werror=cast-function-type]
  366 |   ((u64 (*)(u64, u64, u64, u64, u64))(x))
      |    ^
kernel/bpf/verifier.c:12977:17: note: in expansion of macro 'BPF_CAST_CALL'
12977 |     insn->imm = BPF_CAST_CALL(ops->map_redirect) -
      |                 ^~~~~~~~~~~~~
cc1: all warnings being treated as errors

All these are already fixed in bpf-next.

Caused by commit

  ffea83dd8823 ("Makefile: Enable -Wcast-function-type")

I have reverted that commit for today.

I've just removed that commit from my -next tree, while I
take a look at the ftrace warnings.

Thanks!
--
Gustavo