udpgro.sh/udpgro_bench.sh from selftests.net ADT test failure with linux-hwe-5.11

[Kleber Sacilotto de Souza]

udpgro.sh and udpgro_bench.sh from selftests.net are failing with hwe-5.11 in focal due to the lack of bpf:

00:27:02 DEBUG| [stdout] # selftests: net: udpgro_bench.sh
00:27:02 DEBUG| [stdout] # Missing xdp_dummy helper. Build bpf selftest first
00:27:02 DEBUG| [stdout] not ok 23 selftests: net: udpgro_bench.sh # exit=255
00:27:02 DEBUG| [stdout] # selftests: net: udpgro.sh
00:27:02 DEBUG| [stdout] # Missing xdp_dummy helper. Build bpf selftest first
00:27:02 DEBUG| [stdout] not ok 24 selftests: net: udpgro.sh # exit=255

Which is caused by a build failure (likely the same issue as bug 1926330):

00:18:21 DEBUG| Running 'sudo sh -c 'echo 1 > /proc/sys/net/ipv4/conf/all/accept_local''
00:18:21 DEBUG| Running 'make -C linux/tools/testing/selftests TARGETS=bpf SKIP_TARGETS= KDIR=/usr/src/linux-headers-5.11.0-20-generic'
00:18:21 DEBUG| [stdout] make: Entering directory '/tmp/autopkgtest.NBLYCG/build.0It/src/autotest/client/tmp/ubuntu_kernel_selftests/src/linux/tools/testing/selftests'
00:18:21 DEBUG| [stdout] make --no-builtin-rules ARCH=x86 -C ../../.. headers_install
00:18:21 DEBUG| [stdout] make[1]: Entering directory '/tmp/autopkgtest.NBLYCG/build.0It/src/autotest/client/tmp/ubuntu_kernel_selftests/src/linux'
00:18:22 DEBUG| [stdout] INSTALL ./usr/include
00:18:22 DEBUG| [stdout] make[1]: Leaving directory '/tmp/autopkgtest.NBLYCG/build.0It/src/autotest/client/tmp/ubuntu_kernel_selftests/src/linux'
00:18:22 DEBUG| [stdout] make[1]: Entering directory '/tmp/autopkgtest.NBLYCG/build.0It/src/autotest/client/tmp/ubuntu_kernel_selftests/src/linux/tools/testing/selftests/bpf'
00:18:22 DEBUG| [stdout] make[1]: Leaving directory '/tmp/autopkgtest.NBLYCG/build.0It/src/autotest/client/tmp/ubuntu_kernel_selftests/src/linux/tools/testing/selftests/bpf'
00:18:22 DEBUG| [stderr] Makefile:125: *** Cannot find a vmlinux for VMLINUX_BTF at any of " ../../../../vmlinux /sys/kernel/btf/vmlinux /boot/vmlinux-5.11.0-20-generic". Stop.
00:18:22 DEBUG| [stdout] make: Leaving directory '/tmp/autopkgtest.NBLYCG/build.0It/src/autotest/client/tmp/ubuntu_kernel_selftests/src/linux/tools/testing/selftests'
00:18:22 DEBUG| [stderr] make: *** [Makefile:165: all] Error 2

=======================
Testing failed on:
    amd64: https://autopkgtest.ubuntu.com/results/autopkgtest-focal/focal/amd64/l/linux-hwe-5.11/20210612_013139_52bf0@/log.gz
    arm64: https://autopkgtest.ubuntu.com/results/autopkgtest-focal/focal/arm64/l/linux-hwe-5.11/20210612_185828_49cb4@/log.gz
    ppc64el: https://autopkgtest.ubuntu.com/results/autopkgtest-focal/focal/ppc64el/l/linux-hwe-5.11/20210612_011655_0d30e@/log.gz
    s390x: https://autopkgtest.ubuntu.com/results/autopkgtest-focal/focal/s390x/l/linux-hwe-5.11/20210611_233218_cf940@/log.gz

[Po-Hsu Lin (cypressyew)]

Possible dup with lp:1932239