On Thu, Oct 12, 2023 at 6:40 AM Tetsuo Handa <penguin-kernel@xxxxxxxxxxxxxxxxxxx> wrote: > > Hello. > > I'm having problem with finding BPF LSM examples that work. > I tried building tools/testing/selftests/bpf/progs/lsm.c and > tools/testing/selftests/bpf/prog_tests/test_lsm.c explained at > https://docs.kernel.org/bpf/prog_lsm.html , but got a lot of errors. Make sure you a) have necessary kernel configs set up (see [0], there are also arch-specific configs) and b) build kernel before building selftests, because selftests generate vmlinux.h header with all kernel types based on latest built kernel image. [0] https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next.git/tree/tools/testing/selftests/bpf/config > > ---------------------------------------- > root@ubuntu:/usr/src# git clone https://kernel.googlesource.com/pub/scm/linux/kernel/git/torvalds/linux.git > Cloning into 'linux'... > remote: Total 9723739 (delta 8227084), reused 9723739 (delta 8227084) > Receiving objects: 100% (9723739/9723739), 1.81 GiB | 4.04 MiB/s, done. > Resolving deltas: 100% (8227084/8227084), done. > Checking objects: 100% (33554432/33554432), done. > Updating files: 100% (81759/81759), done. > root@ubuntu:/usr/src# cd linux > root@ubuntu:/usr/src/linux# git describe > v6.6-rc5-72-g401644852d0b > root@ubuntu:/usr/src/linux# make -s headers > root@ubuntu:/usr/src/linux# make -sC tools/testing/selftests/bpf/ > MKDIR libbpf > Warning: Kernel ABI header at 'tools/include/uapi/linux/if_xdp.h' differs from latest version at 'include/uapi/linux/if_xdp.h' > TEST-HDR [test_progs] tests.h > EXT-OBJ [test_progs] testing_helpers.o > EXT-OBJ [test_progs] cap_helpers.o > EXT-OBJ [test_progs] unpriv_helpers.o > BINARY test_verifier > BINARY test_tag > MKDIR bpftool > > GEN vmlinux.h > CLNG-BPF [test_maps] async_stack_depth.bpf.o > progs/async_stack_depth.c:8:19: error: field has incomplete type 'struct bpf_timer' > struct bpf_timer timer; > ^ > /usr/src/linux/tools/testing/selftests/bpf/tools/include/bpf/bpf_helper_defs.h:41:8: note: forward declaration of 'struct bpf_timer' > struct bpf_timer; > ^ > 1 error generated. > make: *** [Makefile:598: /usr/src/linux/tools/testing/selftests/bpf/async_stack_depth.bpf.o] Error 1 > ---------------------------------------- > > To fix these errors, something like the following > (this seems to be a fraction) is needed. What am I missing? > kernel image used for vmlinux.h generation is probably too old [...]
