linux-stable.git/tools/bpf/bpftool/Makefile, branch linux-rolling-lts

bpftool: Fix dependencies for static build

2026-03-04T12:19:42+00:00

[ Upstream commit 08a7491843224f8b96518fbe70d9e48163046054 ]

When building selftests/bpf with EXTRA_LDFLAGS=-static the follwoing
error happens:

  LINK    /ws/linux/tools/testing/selftests/bpf/tools/build/bpftool/bootstrap/bpftool
/usr/bin/x86_64-linux-gnu-ld.bfd: /usr/lib/gcc/x86_64-linux-gnu/15/../../../x86_64-linux-gnu/libcrypto.a(libcrypto-lib-dso_dlfcn.o): in function `dlfcn_globallookup':
   [...]
/usr/bin/x86_64-linux-gnu-ld.bfd: /usr/lib/gcc/x86_64-linux-gnu/15/../../../x86_64-linux-gnu/libcrypto.a(libcrypto-lib-c_zlib.o): in function `zlib_oneshot_expand_block':
(.text+0xc64): undefined reference to `uncompress'
/usr/bin/x86_64-linux-gnu-ld.bfd: /usr/lib/gcc/x86_64-linux-gnu/15/../../../x86_64-linux-gnu/libcrypto.a(libcrypto-lib-c_zlib.o): in function `zlib_oneshot_compress_block':
(.text+0xce4): undefined reference to `compress'
collect2: error: ld returned 1 exit status
make[1]: *** [Makefile:252: /ws/linux/tools/testing/selftests/bpf/tools/build/bpftool/bootstrap/bpftool] Error 1
make: *** [Makefile:327: /ws/linux/tools/testing/selftests/bpf/tools/sbin/bpftool] Error 2
make: *** Waiting for unfinished jobs....

This is caused by wrong order of dependencies in the Makefile. Fix it.

Signed-off-by: Ihor Solodrai 
Signed-off-by: Andrii Nakryiko 
Link: https://lore.kernel.org/bpf/20260128211255.376933-1-ihor.solodrai@linux.dev
Signed-off-by: Sasha Levin

bpftool: Add support for signing BPF programs

2025-09-23T02:17:55+00:00

Two modes of operation being added:

Add two modes of operation:

* For prog load, allow signing a program immediately before loading. This
  is essential for command-line testing and administration.

      bpftool prog load -S -k  -i  fentry_test.bpf.o

* For gen skeleton, embed a pre-generated signature into the C skeleton
  file. This supports the use of signed programs in compiled applications.

      bpftool gen skeleton -S -k  -i  fentry_test.bpf.o

Generation of the loader program and its metadata map is implemented in
libbpf (bpf_obj__gen_loader). bpftool generates a skeleton that loads
the program and automates the required steps: freezing the map, creating
an exclusive map, loading, and running. Users can use standard libbpf
APIs directly or integrate loader program generation into their own
toolchains.

Signed-off-by: KP Singh 
Acked-by: Quentin Monnet 
Link: https://lore.kernel.org/r/20250921160120.9711-5-kpsingh@kernel.org
Signed-off-by: Alexei Starovoitov

Merge tag 'bpf-next-6.15' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next

2025-03-30T19:43:03+00:00

Pull bpf updates from Alexei Starovoitov:
 "For this merge window we're splitting BPF pull request into three for
  higher visibility: main changes, res_spin_lock, try_alloc_pages.

  These are the main BPF changes:

   - Add DFA-based live registers analysis to improve verification of
     programs with loops (Eduard Zingerman)

   - Introduce load_acquire and store_release BPF instructions and add
     x86, arm64 JIT support (Peilin Ye)

   - Fix loop detection logic in the verifier (Eduard Zingerman)

   - Drop unnecesary lock in bpf_map_inc_not_zero() (Eric Dumazet)

   - Add kfunc for populating cpumask bits (Emil Tsalapatis)

   - Convert various shell based tests to selftests/bpf/test_progs
     format (Bastien Curutchet)

   - Allow passing referenced kptrs into struct_ops callbacks (Amery
     Hung)

   - Add a flag to LSM bpf hook to facilitate bpf program signing
     (Blaise Boscaccy)

   - Track arena arguments in kfuncs (Ihor Solodrai)

   - Add copy_remote_vm_str() helper for reading strings from remote VM
     and bpf_copy_from_user_task_str() kfunc (Jordan Rome)

   - Add support for timed may_goto instruction (Kumar Kartikeya
     Dwivedi)

   - Allow bpf_get_netns_cookie() int cgroup_skb programs (Mahe Tardy)

   - Reduce bpf_cgrp_storage_busy false positives when accessing cgroup
     local storage (Martin KaFai Lau)

   - Introduce bpf_dynptr_copy() kfunc (Mykyta Yatsenko)

   - Allow retrieving BTF data with BTF token (Mykyta Yatsenko)

   - Add BPF kfuncs to set and get xattrs with 'security.bpf.' prefix
     (Song Liu)

   - Reject attaching programs to noreturn functions (Yafang Shao)

   - Introduce pre-order traversal of cgroup bpf programs (Yonghong
     Song)"

* tag 'bpf-next-6.15' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (186 commits)
  selftests/bpf: Add selftests for load-acquire/store-release when register number is invalid
  bpf: Fix out-of-bounds read in check_atomic_load/store()
  libbpf: Add namespace for errstr making it libbpf_errstr
  bpf: Add struct_ops context information to struct bpf_prog_aux
  selftests/bpf: Sanitize pointer prior fclose()
  selftests/bpf: Migrate test_xdp_vlan.sh into test_progs
  selftests/bpf: test_xdp_vlan: Rename BPF sections
  bpf: clarify a misleading verifier error message
  selftests/bpf: Add selftest for attaching fexit to __noreturn functions
  bpf: Reject attaching fexit/fmod_ret to __noreturn functions
  bpf: Only fails the busy counter check in bpf_cgrp_storage_get if it creates storage
  bpf: Make perf_event_read_output accessible in all program types.
  bpftool: Using the right format specifiers
  bpftool: Add -Wformat-signedness flag to detect format errors
  selftests/bpf: Test freplace from user namespace
  libbpf: Pass BPF token from find_prog_btf_id to BPF_BTF_GET_FD_BY_ID
  bpf: Return prog btf_id without capable check
  bpf: BPF token support for BPF_BTF_GET_FD_BY_ID
  bpf, x86: Fix objtool warning for timed may_goto
  bpf: Check map->record at the beginning of check_and_free_fields()
  ...

bpftool: Add -Wformat-signedness flag to detect format errors

2025-03-17T20:50:56+00:00

This commit adds the -Wformat-signedness compiler flag to detect and
prevent printf format errors, where signed or unsigned types are
mismatched with format specifiers. This helps to catch potential issues at
compile-time, ensuring that our code is more robust and reliable. With
this flag, the compiler will now warn about incorrect format strings, such
as using %d with unsigned types or %u with signed types.

Signed-off-by: Jiayuan Chen 
Signed-off-by: Andrii Nakryiko 
Link: https://lore.kernel.org/bpf/20250311112809.81901-2-jiayuan.chen@linux.dev

tools: Remove redundant quiet setup

2025-02-18T19:27:43+00:00

Q is exported from Makefile.include so it is not necessary to manually
set it.

Reviewed-by: Jiri Olsa 
Signed-off-by: Charlie Jenkins 
Acked-by: Andrii Nakryiko 
Acked-by: Quentin Monnet 
Cc: Adrian Hunter 
Cc: Alexander Shishkin 
Cc: Alexei Starovoitov 
Cc: Benjamin Tissoires 
Cc: Daniel Borkmann 
Cc: Daniel Lezcano 
Cc: Eduard Zingerman 
Cc: Hao Luo 
Cc: Ian Rogers 
Cc: Ingo Molnar 
Cc: Jiri Kosina 
Cc: John Fastabend 
Cc: Josh Poimboeuf 
Cc: KP Singh 
Cc: Lukasz Luba 
Cc: Mark Rutland 
Cc: Martin KaFai Lau 
Cc: Mykola Lysenko 
Cc: Namhyung Kim 
Cc: Peter Zijlstra 
Cc: Rafael J. Wysocki 
Cc: Shuah Khan 
Cc: Song Liu 
Cc: Stanislav Fomichev 
Cc: Steven Rostedt (VMware) 
Cc: Yonghong Song 
Cc: Zhang Rui 
Link: https://lore.kernel.org/r/20250213-quiet_tools-v3-2-07de4482a581@rivosinc.com
Signed-off-by: Arnaldo Carvalho de Melo

bpftool: Link zstd lib required by libelf

2024-12-18T19:24:32+00:00

When the feature libelf-zstd is detected, the zstd lib is required by
libelf.  Link the zstd lib in this case.

Reviewed-by: Quentin Monnet 
Signed-off-by: Leo Yan 
Tested-by: Namhyung Kim 
Acked-by: Andrii Nakryiko 
Cc: Adrian Hunter 
Cc: Alexei Starovoitov 
Cc: Daniel Borkmann 
Cc: Eduard Zingerman 
Cc: Guilherme Amadio 
Cc: Hao Luo 
Cc: Ian Rogers 
Cc: James Clark 
Cc: Jiri Olsa 
Cc: John Fastabend 
Cc: KP Singh 
Cc: Kan Liang 
Cc: Martin KaFai Lau 
Cc: Nick Terrell 
Cc: Song Liu 
Cc: Stanislav Fomichev 
Cc: Yonghong Song 
Link: https://lore.kernel.org/r/20241215221223.293205-4-leo.yan@arm.com
Signed-off-by: Arnaldo Carvalho de Melo

bpftool: Prevent setting duplicate _GNU_SOURCE in Makefile

2024-11-01T19:37:01+00:00

When building selftests with CFLAGS set via env variable, the value of
CFLAGS is propagated into bpftool Makefile (called from selftests
Makefile). This makes the compilation fail as _GNU_SOURCE is defined two
times - once from selftests Makefile (by including lib.mk) and once from
bpftool Makefile (by calling `llvm-config --cflags`):

    $ CFLAGS="" make -C tools/testing/selftests/bpf
    [...]
    CC      /bpf-next/tools/testing/selftests/bpf/tools/build/bpftool/btf.o
    : error: "_GNU_SOURCE" redefined [-Werror]
    : note: this is the location of the previous definition
    cc1: all warnings being treated as errors
    [...]

Filter out -D_GNU_SOURCE from the result of `llvm-config --cflags` in
bpftool Makefile to prevent this error.

Signed-off-by: Viktor Malik 
Signed-off-by: Andrii Nakryiko 
Acked-by: Quentin Monnet 
Acked-by: Jiri Olsa 
Link: https://lore.kernel.org/bpf/acec3108b62d4df1436cda777e58e93e033ac7a7.1730449390.git.vmalik@redhat.com

bpftool: Fix make dependencies for vmlinux.h

2024-05-18T17:46:16+00:00

With pre-generated vmlinux.h there is no dependency on neither vmlinux
nor bootstrap bpftool. Define dependencies separately for both modes.
This avoids needless rebuilds in some corner cases.

Suggested-by: Jan Stancek 
Signed-off-by: Artem Savkov 
Signed-off-by: Andrii Nakryiko 
Acked-by: Quentin Monnet 
Link: https://lore.kernel.org/bpf/20240513112658.43691-1-asavkov@redhat.com
Signed-off-by: Alexei Starovoitov

bpftool, selftests/hid/bpf: Fix 29 clang warnings

2024-05-06T21:39:36+00:00

When building either tools/bpf/bpftool, or tools/testing/selftests/hid,
(the same Makefile is used for these), clang generates many instances of
the following:

    "clang: warning: -lLLVM-17: 'linker' input unused"

Quentin points out that the LLVM version is only required in $(LIBS),
not in $(CFLAGS), so the fix is to remove it from CFLAGS.

Suggested-by: Quentin Monnet 
Signed-off-by: John Hubbard 
Signed-off-by: Andrii Nakryiko 
Acked-by: Quentin Monnet 
Link: https://lore.kernel.org/bpf/20240505230054.13813-1-jhubbard@nvidia.com

bpftool: Clean up HOST_CFLAGS, HOST_LDFLAGS for bootstrap bpftool

2024-03-21T06:33:49+00:00

Bpftool's Makefile uses $(HOST_CFLAGS) to build the bootstrap version of
bpftool, in order to pick the flags for the host (where we run the
bootstrap version) and not for the target system (where we plan to run
the full bpftool binary). But we pass too much information through this
variable.

In particular, we set HOST_CFLAGS by copying most of the $(CFLAGS); but
we do this after the feature detection for bpftool, which means that
$(CFLAGS), hence $(HOST_CFLAGS), contain all macro definitions for using
the different optional features. For example, -DHAVE_LLVM_SUPPORT may be
passed to the $(HOST_CFLAGS), even though the LLVM disassembler is not
used in the bootstrap version, and the related library may even be
missing for the host architecture.

A similar thing happens with the $(LDFLAGS), that we use unchanged for
linking the bootstrap version even though they may contains flags to
link against additional libraries.

To address the $(HOST_CFLAGS) issue, we move the definition of
$(HOST_CFLAGS) earlier in the Makefile, before the $(CFLAGS) update
resulting from the feature probing - none of which being relevant to the
bootstrap version. To clean up the $(LDFLAGS) for the bootstrap version,
we introduce a dedicated $(HOST_LDFLAGS) variable that we base on
$(LDFLAGS), before the feature probing as well.

On my setup, the following macro and libraries are removed from the
compiler invocation to build bpftool after this patch:

  -DUSE_LIBCAP
  -DHAVE_LLVM_SUPPORT
  -I/usr/lib/llvm-17/include
  -D_GNU_SOURCE
  -D__STDC_CONSTANT_MACROS
  -D__STDC_FORMAT_MACROS
  -D__STDC_LIMIT_MACROS
  -lLLVM-17
  -L/usr/lib/llvm-17/lib

Another advantage of cleaning up these flags is that displaying
available features with "bpftool version" becomes more accurate for the
bootstrap bpftool, and no longer reflects the features detected (and
available only) for the final binary.

Cc: Jean-Philippe Brucker 
Signed-off-by: Quentin Monnet 
Acked-by: Jiri Olsa 
Message-ID: <20240320014103.45641-1-qmo@kernel.org>
Signed-off-by: Alexei Starovoitov