[SRU][J][PATCH 0/1] Fix bpf selftests build failure after v5.15.139 update

[Roxana Nicolescu]

BugLink: https://bugs.launchpad.net/bugs/2054567

Sru justification

[Impact]
Upstream v5.15.139 (#lp2049432) brought commit
 "selftests/bpf: Test tail call counting with bpf2bpf and data on stack"
that affects one of the bpf kselftests. Because LIBBPF_OPTS macro does not
 exist, it does not compile. Error is shown below.

[Fix]
Cherry-pick commit "libbpf: Rename DECLARE_LIBBPF_OPTS into LIBBPF_OPTS"

[Test]
This should be solved soon, but compileselftests debian rule does not
compile bpf selftests.
I tested it by using our regression testing tooling, but same results can
be achieved by running:
$ make -C linux/tools/testing/selftests TARGETS=bpf SKIP_TARGETS= clean all KDIR=/usr/src/linux-headers-5.15.0-<version>-generic
from the linux tree directory

Without the fix, it fails to compile:
  /root/autotest/client/tmp/ubuntu_bpf/src/linux/tools/testing/selftests/bpf/prog_tests/tailcalls.c: In function ‘test_tailcall_bpf2bpf_6’:
  /root/autotest/client/tmp/ubuntu_bpf/src/linux/tools/testing/selftests/bpf/prog_tests/tailcalls.c:822:9: warning: implicit declaration of function ‘LIBBPF_OPTS’; did you mean ‘LIBBPF_API’? [-Wimplicit-function-declaration]
    822 | LIBBPF_OPTS(bpf_test_run_opts, topts,
        | ^~~~~~~~~~~
        | LIBBPF_API
  /root/autotest/client/tmp/ubuntu_bpf/src/linux/tools/testing/selftests/bpf/prog_tests/tailcalls.c:822:21: error: ‘bpf_test_run_opts’ undeclared (first use in this function)
    822 | LIBBPF_OPTS(bpf_test_run_opts, topts,
        | ^~~~~~~~~~~~~~~~~
  /root/autotest/client/tmp/ubuntu_bpf/src/linux/tools/testing/selftests/bpf/prog_tests/tailcalls.c:822:21: note: each undeclared identifier is reported only once for each function it appears in
  /root/autotest/client/tmp/ubuntu_bpf/src/linux/tools/testing/selftests/bpf/prog_tests/tailcalls.c:822:40: error: ‘topts’ undeclared (first use in this function)
    822 | LIBBPF_OPTS(bpf_test_run_opts, topts,
        | ^~~~~
  /root/autotest/client/tmp/ubuntu_bpf/src/linux/tools/testing/selftests/bpf/prog_tests/tailcalls.c:823:17: error: expected expression before ‘.’ token
    823 | .data_in = &pkt_v4,
        | ^
  make[1]: *** [Makefile:471: /root/autotest/client/tmp/ubuntu_bpf/src/linux/tools/testing/selftests/bpf/tailcalls.test.o] Error 1
  make: *** [Makefile:172: all] Error 2

With the fix, it compiles.

[Regression potential]
The only place this is being used is selftests, so the risk is very low.

Andrii Nakryiko (1):
  libbpf: Rename DECLARE_LIBBPF_OPTS into LIBBPF_OPTS

 tools/lib/bpf/bpf.h           | 1 +
 tools/lib/bpf/libbpf_common.h | 2 +-
 tools/lib/bpf/libbpf_legacy.h | 1 +
 3 files changed, 3 insertions(+), 1 deletion(-)

-- 
2.34.1