On Mon, Jan 11, 2021 at 12:33 PM Sedat Dilek <[email protected]> wrote: > > On Mon, Jan 11, 2021 at 11:29 AM Salvatore Bonaccorso <[email protected]> > wrote: > > > > > > On Mon, Jan 11, 2021 at 09:57:43AM +0100, Sedat Dilek wrote: > > > Hi, > > > > > > yesterday, I installed linux-image-5.10.0-1-amd64 version 5.10.5-1 > > > from Debian/unstable. > > > > > > I am building custom Linux-kernels mostly to test with LLVM/Clang and > > > use Debian's kernel-config file as a base for my work. > > > > > > With CONFIG_DEBUG_INFO_BTF=y there is a requirement for pahole binary > > > from dwarves package. > > > > > > The requirement is coded in [1]: > > > > > > if ! [ -x "$(command -v ${PAHOLE})" ]; then > > > echo >&2 "BTF: ${1}: pahole (${PAHOLE}) is not available" > > > return 1 > > > fi > > > > > > Is there an install-recommendation for dwarves package? > > > If not - I would like to open a bug-report. > > > > > > If you need further information, please let me know. > > > > this change happened in > > https://salsa.debian.org/kernel-team/linux/-/commit/929891281c61ce4403ddd869664c949692644a2f > > (actually earlier, then reverted and enabled for a subset of > > architectures wiith the above commit). > > > > For the Debian build it adds as well the Build-Depends on dwarves (>= > > 1.16~). > > > > Did I understood your question correctly? > > > > Hi Salvatore, > > That commit looks good to me. > > Anyway, it breaks here CONFIG_DEBUG_INFO_BTF=y: > > + [ -n y -a -n y ] > + info BTFIDS vmlinux > + [ != silent_ ] > + printf %-7s %s\n BTFIDS vmlinux > BTFIDS vmlinux > + ./tools/bpf/resolve_btfids/resolve_btfids vmlinux > FAILED: load BTF from vmlinux: Invalid argument > + on_exit > + [ 255 -ne 0 ] > + cleanup > + rm -f .btf.vmlinux.bin.o > > Any comments? >
According to [1]: Q: Where do I find LLVM with BPF support? OK, I see my selfmade LLVM toolchain has no BPF support. $ which llc /home/dileks/src/llvm-toolchain/install/bin/llc $ llc --version LLVM (http://llvm.org/): LLVM version 11.0.1 Optimized build. Default target: x86_64-unknown-linux-gnu Host CPU: sandybridge Registered Targets: x86 - 32-bit X86: Pentium-Pro and above x86-64 - 64-bit X86: EM64T and AMD64 Debian's LLC has BPF support: $ /usr/bin/llc-11 --version | grep -i bpf bpf - BPF (host endian) bpfeb - BPF (big endian) bpfel - BPF (little endian) I am sorry for the noise. - Sedat - [1] https://www.kernel.org/doc/html/latest/bpf/bpf_devel_QA.html?highlight=pahole#llvm
