Add a type cast for set8->pairs to fix below compile warning:

main.c: In function 'sets_patch':
main.c:699:50: warning: comparison of distinct pointer types lacks a cast
  699 |        BUILD_BUG_ON(set8->pairs != &set8->pairs[0].id);
      |                                 ^~

Fixes: 9707ac4fe2f5 ("tools/resolve_btfids: Refactor set sorting with types from btf_ids.h")
Signed-off-by: Liwei Song <liwei.song.lsong@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/bpf/20240722083305.4009723-1-liwei.song.lsong@gmail.com

The usage help for "bpftool prog help" contains a ° instead of the _
symbol for cgroup/sendmsg_unix. Fix the typo.

Fixes: 8b3cba987e6d ("bpftool: Add support for cgroup unix socket address hooks")
Signed-off-by: Donald Hunter <donald.hunter@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Quentin Monnet <qmo@kernel.org>
Link: https://lore.kernel.org/bpf/20240717134508.77488-1-donald.hunter@gmail.com

Old versions of libbpf don't handle varying sizes of bpf_map_skeleton
struct correctly. As such, BPF skeleton generated by newest bpftool
might not be compatible with older libbpf (though only when libbpf is
used as a shared library), even though it, by design, should.

Going forward libbpf will be fixed, plus we'll release bug fixed
versions of relevant old libbpfs, but meanwhile try to mitigate from
bpftool side by conservatively assuming older and smaller definition of
bpf_map_skeleton, if possible. Meaning, if there are no struct_ops maps.

If there are struct_ops, then presumably user would like to have
auto-attaching logic and struct_ops map link placeholders, so use the
full bpf_map_skeleton definition in that case.

Acked-by: Quentin Monnet <qmo@kernel.org>
Co-developed-by: Mykyta Yatsenko <yatsenko@meta.com>
Signed-off-by: Mykyta Yatsenko <yatsenko@meta.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20240708204540.4188946-2-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

As Quentin said [0], BPF map pinning will fail if the pinmaps path is not
under the bpffs, like:

  libbpf: specified path /home/ubuntu/test/sock_ops_map is not on BPF FS
  Error: failed to pin all maps

  [0] https://github.com/libbpf/bpftool/issues/146

Fixes: 3767a94b3253 ("bpftool: add pinmaps argument to the load/loadall")
Signed-off-by: Tao Chen <chen.dylane@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Tested-by: Quentin Monnet <qmo@kernel.org>
Reviewed-by: Quentin Monnet <qmo@kernel.org>
Link: https://lore.kernel.org/bpf/20240702131150.15622-1-chen.dylane@gmail.com

New versions of bpftool now emit additional link placeholders for BPF
maps (struct_ops maps are the only maps right now that support
attachment), and set up BPF skeleton in such a way that libbpf will
auto-attach BPF maps automatically, assumming libbpf is recent enough
(v1.5+). Old libbpf will do nothing with those links and won't attempt
to auto-attach maps. This allows user code to handle both pre-v1.5 and
v1.5+ versions of libbpf at runtime, if necessary.

But if users don't have (or don't want to) control bpftool version that
generates skeleton, then they can't just assume that skeleton will have
link placeholders. To make this detection possible and easy, let's add
the following to generated skeleton header file:

  #define BPF_SKEL_SUPPORTS_MAP_AUTO_ATTACH 1

This can be used during compilation time to guard code that accesses
skel->links.<map> slots.

Note, if auto-attachment is undesirable, libbpf allows to disable this
through bpf_map__set_autoattach(map, false). This is necessary only on
libbpf v1.5+, older libbpf doesn't support map auto-attach anyways.

Libbpf version can be detected at compilation time using
LIBBPF_MAJOR_VERSION and LIBBPF_MINOR_VERSION macros, or at runtime with
libbpf_major_version() and libbpf_minor_version() APIs.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Quentin Monnet <qmo@kernel.org>
Link: https://lore.kernel.org/bpf/20240618183832.2535876-1-andrii@kernel.org

Now that btf_parse_elf() handles .BTF.base section presence,
we need to ensure that resolve_btfids uses .BTF.base when present
rather than the vmlinux base BTF passed in via the -B option.
Detect .BTF.base section presence and unset the base BTF path
to ensure that BTF ELF parsing will do the right thing.

Signed-off-by: Alan Maguire <alan.maguire@oracle.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Reviewed-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/bpf/20240613095014.357981-7-alan.maguire@oracle.com

This patch enables dumping kfunc prototypes from bpftool. This is useful
b/c with this patch, end users will no longer have to manually define
kfunc prototypes. For the kernel tree, this also means we can optionally
drop kfunc prototypes from:

        tools/testing/selftests/bpf/bpf_kfuncs.h
        tools/testing/selftests/bpf/bpf_experimental.h

Example usage:

        $ make PAHOLE=/home/dxu/dev/pahole/build/pahole -j30 vmlinux

        $ ./tools/bpf/bpftool/bpftool btf dump file ./vmlinux format c | rg "__ksym;" | head -3
        extern void cgroup_rstat_updated(struct cgroup *cgrp, int cpu) __weak __ksym;
        extern void cgroup_rstat_flush(struct cgroup *cgrp) __weak __ksym;
        extern struct bpf_key *bpf_lookup_user_key(u32 serial, u64 flags) __weak __ksym;

Signed-off-by: Daniel Xu <dxu@dxuuu.xyz>
Link: https://lore.kernel.org/r/bf6c08f9263c4bd9d10a717de95199d766a13f61.1718207789.git.dxu@dxuuu.xyz
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

When CONFIG_NETKIT=y,
bpftool-cgroup shows error even if the cgroup's path is correct:

$ bpftool cgroup tree /sys/fs/cgroup
CgroupPath
ID       AttachType      AttachFlags     Name
Error: can't query bpf programs attached to /sys/fs/cgroup: No such device or address

>From strace and kernel tracing, I found netkit returned ENXIO and this command failed.
I think this AttachType(BPF_NETKIT_PRIMARY) is not relevant to cgroup.

bpftool-cgroup should query just only cgroup-related attach types.

v2->v3:
  - removed an unnecessary check

v1->v2:
  - used an array of cgroup attach types

Signed-off-by: Kenta Tada <tadakentaso@gmail.com>
Reviewed-by: Quentin Monnet <qmo@kernel.org>
Link: https://lore.kernel.org/r/20240607111704.6716-1-tadakentaso@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

Daniel Borkmann says:

====================
pull-request: bpf-next 2024-06-06

We've added 54 non-merge commits during the last 10 day(s) which contain
a total of 50 files changed, 1887 insertions(+), 527 deletions(-).

The main changes are:

1) Add a user space notification mechanism via epoll when a struct_ops
   object is getting detached/unregistered, from Kui-Feng Lee.

2) Big batch of BPF selftest refactoring for sockmap and BPF congctl
   tests, from Geliang Tang.

3) Add BTF field (type and string fields, right now) iterator support
   to libbpf instead of using existing callback-based approaches,
   from Andrii Nakryiko.

4) Extend BPF selftests for the latter with a new btf_field_iter
   selftest, from Alan Maguire.

5) Add new kfuncs for a generic, open-coded bits iterator,
   from Yafang Shao.

6) Fix BPF selftests' kallsyms_find() helper under kernels configured
   with CONFIG_LTO_CLANG_THIN, from Yonghong Song.

7) Remove a bunch of unused structs in BPF selftests,
   from David Alan Gilbert.

8) Convert test_sockmap section names into names understood by libbpf
   so it can deduce program type and attach type, from Jakub Sitnicki.

9) Extend libbpf with the ability to configure log verbosity
   via LIBBPF_LOG_LEVEL environment variable, from Mykyta Yatsenko.

10) Fix BPF selftests with regards to bpf_cookie and find_vma flakiness
    in nested VMs, from Song Liu.

11) Extend riscv32/64 JITs to introduce shift/add helpers to generate Zba
    optimization, from Xiao Wang.

12) Enable BPF programs to declare arrays and struct fields with kptr,
    bpf_rb_root, and bpf_list_head, from Kui-Feng Lee.

* tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (54 commits)
  selftests/bpf: Drop useless arguments of do_test in bpf_tcp_ca
  selftests/bpf: Use start_test in test_dctcp in bpf_tcp_ca
  selftests/bpf: Use start_test in test_dctcp_fallback in bpf_tcp_ca
  selftests/bpf: Add start_test helper in bpf_tcp_ca
  selftests/bpf: Use connect_to_fd_opts in do_test in bpf_tcp_ca
  libbpf: Auto-attach struct_ops BPF maps in BPF skeleton
  selftests/bpf: Add btf_field_iter selftests
  selftests/bpf: Fix send_signal test with nested CONFIG_PARAVIRT
  libbpf: Remove callback-based type/string BTF field visitor helpers
  bpftool: Use BTF field iterator in btfgen
  libbpf: Make use of BTF field iterator in BTF handling code
  libbpf: Make use of BTF field iterator in BPF linker code
  libbpf: Add BTF field iterator
  selftests/bpf: Ignore .llvm.<hash> suffix in kallsyms_find()
  selftests/bpf: Fix bpf_cookie and find_vma in nested VM
  selftests/bpf: Test global bpf_list_head arrays.
  selftests/bpf: Test global bpf_rb_root arrays and fields in nested struct types.
  selftests/bpf: Test kptr arrays and kptrs in nested struct fields.
  bpf: limit the number of levels of a nested struct type.
  bpf: look into the types of the fields of a struct type recursively.
  ...
====================

Link: https://lore.kernel.org/r/20240606223146.23020-1-daniel@iogearbox.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Similarly to `bpf_program`, support `bpf_map` automatic attachment in
`bpf_object__attach_skeleton`. Currently only struct_ops maps could be
attached.

On bpftool side, code-generate links in skeleton struct for struct_ops maps.
Similarly to `bpf_program_skeleton`, set links in `bpf_map_skeleton`.

On libbpf side, extend `bpf_map` with new `autoattach` field to support
enabling or disabling autoattach functionality, introducing
getter/setter for this field.

`bpf_object__(attach|detach)_skeleton` is extended with
attaching/detaching struct_ops maps logic.

Signed-off-by: Mykyta Yatsenko <yatsenko@meta.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20240605175135.117127-1-yatsenko@meta.com