Introduce SKIP_LLVM, SKIP_LIBBFD, and SKIP_CRYPTO build flags that let
users build bpftool without these optional dependencies.
SKIP_LLVM=1 skips LLVM even when detected. SKIP_LIBBFD=1 prevents the
libbfd JIT disassembly fallback when LLVM is absent. Together, they
produce a bpftool with no disassembly support.
SKIP_CRYPTO=1 excludes sign.c and removes the -lcrypto link dependency.
Inline stubs in main.h return errors with a clear message if signing
functions are called at runtime.
Use BPFTOOL_WITHOUT_CRYPTO (not HAVE_LIBCRYPTO_SUPPORT) as the C
define, following the BPFTOOL_WITHOUT_SKELETONS naming convention for
bpftool-internal build config, leaving HAVE_LIBCRYPTO_SUPPORT free for
proper feature detection in the future.
All three flags are propagated through the selftests Makefile to bpftool
sub-builds.
Signed-off-by: Mykyta Yatsenko <yatsenko@meta.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20260312-b4-bpftool_build-v2-1-4c9d57133644@meta.com
Add support for specifying multiple file sources in 'bpftool btf dump'
to generate a single C header containing types from vmlinux plus
multiple kernel modules:
bpftool btf dump file /sys/kernel/btf/mod1 file /sys/kernel/btf/mod2 format c
This is useful for BPF programs that need to access types defined in
kernel modules. Previously this required a separate bpftool invocation
for each module, producing separate headers that could not be combined
due to overlapping vmlinux type definitions.
The implementation collects all file paths, then for the multi-file
case creates an empty split BTF on the vmlinux base and iteratively
merges each module's types into it via btf__add_btf(). The single-file
code path is preserved exactly to avoid any regression risk.
Auto-detection of vmlinux as the base BTF from sysfs paths works as
before. If vmlinux itself appears in the file list it is skipped with
a warning since its types are already provided by the base.
Assisted-by: Claude:claude-opus-4-6
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Reviewed-by: Alan Maguire <alan.maguire@oracle.com>
Link: https://lore.kernel.org/bpf/b19c2760ffe48cec546dd3810d237f8cad20d606.1772657690.git.josef@toxicpanda.com
Netlink requires that the recv buffer used during dumps is at least
min(PAGE_SIZE, 8k) (see the man page). Otherwise the messages will
get truncated. Make sure bpftool follows this requirement, avoid
missing information on systems with large pages.
Acked-by: Quentin Monnet <qmo@kernel.org>
Fixes: 7084566a23 ("tools/bpftool: Remove libbpf_internal.h usage in bpftool")
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Link: https://lore.kernel.org/r/20260217194150.734701-1-kuba@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
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 <ihor.solodrai@linux.dev>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20260128211255.376933-1-ihor.solodrai@linux.dev
Add support for the 'prepend' option when attaching tcx_ingress and
tcx_egress programs. This option allows inserting a BPF program at
the beginning of the TCX chain instead of appending it at the end.
The implementation uses BPF_F_BEFORE flag which automatically inserts
the program at the beginning of the chain when no relative reference
is specified.
This change includes:
- Modify do_attach_tcx() to support prepend insertion using BPF_F_BEFORE
- Update documentation to describe the new 'prepend' option
- Add bash completion support for the 'prepend' option on tcx attach types
- Add example usage in the documentation
- Add validation to reject 'overwrite' for non-XDP attach types
The 'prepend' option is only valid for tcx_ingress and tcx_egress attach
types. For XDP attach types, the existing 'overwrite' option remains
available.
Example usage:
# bpftool net attach tcx_ingress name tc_prog dev lo prepend
This feature is useful when the order of program execution in the TCX
chain matters and users need to ensure certain programs run first.
Co-developed-by: Siwan Kim <siwan.kim@navercorp.com>
Signed-off-by: Siwan Kim <siwan.kim@navercorp.com>
Signed-off-by: Gyutae Bae <gyutae.bae@navercorp.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Reviewed-by: Quentin Monnet <qmo@kernel.org>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20260112034516.22723-1-gyutae.opensource@navercorp.com
The kernel is now built with -fms-extensions. Anonymous structs or
unions permitted by these extensions have been used in several places,
and can end up in the generated vmlinux.h file, for example:
struct ns_tree {
[...]
};
[...]
struct ns_common {
[...]
union {
struct ns_tree;
struct callback_head ns_rcu;
};
};
Trying to include this header for compiling a tool may result in build
warnings, if the compiler does not expect these extensions. This is the
case, for example, with bpftool:
In file included from skeleton/pid_iter.bpf.c:3:
.../tools/testing/selftests/bpf/tools/build/bpftool/vmlinux.h:64057:3:
warning: declaration does not declare anything
[-Wmissing-declarations]
64057 | struct ns_tree;
| ^~~~~~~~~~~~~~
Fix these build warnings in bpftool by turning on Microsoft extensions
when compiling the two BPF programs that rely on vmlinux.h.
Reported-by: Alexei Starovoitov <ast@kernel.org>
Closes: https://lore.kernel.org/bpf/CAADnVQK9ZkPC7+R5VXKHVdtj8tumpMXm7BTp0u9CoiFLz_aPTg@mail.gmail.com/
Signed-off-by: Quentin Monnet <qmo@kernel.org>
Link: https://lore.kernel.org/r/20251208130748.68371-1-qmo@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Rename bpf_stream_vprintk() to bpf_stream_vprintk_impl().
This makes bpf_stream_vprintk() follow the already established "_impl"
suffix-based naming convention for kfuncs with the bpf_prog_aux
argument provided by the verifier implicitly. This convention will be
taken advantage of with the upcoming KF_IMPLICIT_ARGS feature to
preserve backwards compatibility to BPF programs.
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Mykyta Yatsenko <yatsenko@meta.com>
Link: https://lore.kernel.org/r/20251104-implv2-v3-2-4772b9ae0e06@meta.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Ihor Solodrai <ihor.solodrai@linux.dev>
Commit 40863f4d6e ("bpftool: Add support for signing BPF programs")
added new options for "bpftool prog load" and "bpftool gen skeleton".
This commit brings the relevant update to the bash completion file.
We rework slightly the processing of options to make completion more
resilient for options that take an argument.
Signed-off-by: Quentin Monnet <qmo@kernel.org>
Link: https://lore.kernel.org/r/20250923103802.57695-1-qmo@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
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 <private_key> -i <identity_cert> 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 <private_key> -i <identity_cert> 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 <kpsingh@kernel.org>
Acked-by: Quentin Monnet <qmo@kernel.org>
Link: https://lore.kernel.org/r/20250921160120.9711-5-kpsingh@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
This fixes the build with -Werror -Wall.
btf_dumper.c:71:31: error: variable 'finfo' is uninitialized when passed as a const pointer argument here [-Werror,-Wuninitialized-const-pointer]
71 | info.func_info = ptr_to_u64(&finfo);
| ^~~~~
prog.c:2294:31: error: variable 'func_info' is uninitialized when passed as a const pointer argument here [-Werror,-Wuninitialized-const-pointer]
2294 | info.func_info = ptr_to_u64(&func_info);
|
v2:
- Initialize instead of using memset.
Signed-off-by: Tom Stellard <tstellar@redhat.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Quentin Monnet <qmo@kernel.org>
Link: https://lore.kernel.org/bpf/20250917183847.318163-1-tstellar@redhat.com
With "bpftool prog tracelog", bpftool prints messages from the trace
pipe. To do so, it first needs to find the tracefs mount point to open
the pipe. Bpftool looks at a few "default" locations, including
/sys/kernel/debug/tracing and /sys/kernel/tracing.
Some of these locations, namely /tracing and /trace, are not standard.
They are in the list because some users used to hardcode the tracing
directory to short names; but we have no compelling reason to look at
these locations. If we fail to find the tracefs at the default
locations, we have an additional step to find it by parsing /proc/mounts
anyway, so it's safe to remove these entries from the list of default
locations to check.
Additionally, Alexei reports that looking for the tracefs at
/sys/kernel/debug/tracing may automatically mount the file system under
that location, and generate a kernel log message telling that
auto-mounting there is deprecated. To avoid this message, let's swap the
order for checking the potential mount points: try /sys/kernel/tracing
first, which should be the standard location nowadays. The kernel log
message may still appear if the tracefs is not mounted on
/sys/kernel/tracing when we run bpftool.
Reported-by: Alexei Starovoitov <ast@kernel.org>
Closes: https://lore.kernel.org/r/CAADnVQLcMi5YQhZKsU4z3S2uVUAGu_62C33G2Zx_ruG3uXa-Ug@mail.gmail.com/
Signed-off-by: Quentin Monnet <qmo@kernel.org>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/r/20250915134209.36568-1-qmo@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Extract the kernel configuration file parsing logic from feature.c into
a new read_kernel_config() function in common.c. This includes:
1. Moving the config file handling and option parsing code
2. Adding required headers and struct definition
3. Keeping all existing functionality
The refactoring enables sharing this logic with other components while
maintaining current behavior. This will be used by subsequent patches
that need to check kernel config options.
Signed-off-by: Yuan Chen <chenyuan@kylinos.cn>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Quentin Monnet <qmo@kernel.org>
Acked-by: Yonghong Song <yonghong.song@linux.dev>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/bpf/20250829061107.23905-2-chenyuan_fl@163.com
From bpftool's github repository issue [0]: When a Linux distribution
has the kernel.kptr_restrict set to 2, bpftool prog dump jited returns
"no instructions returned". This message can be puzzling to bpftool
users who are not familiar with kernel BPF internals, so add a small
hint for bpftool users to check the kernel.kptr_restrict setting
similar to the DUMP_XLATED case. Outside of kernel.kptr_restrict, no
instructions could also be returned in case the JIT was disabled.
Signed-off-by: Vincent Li <vincent.mc.li@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://github.com/libbpf/bpftool/issues/184 [0]
Link: https://lore.kernel.org/bpf/20250818165113.15982-1-vincent.mc.li@gmail.com
