Re: [PATCH bpf-next v2 8/8] selftests/bpf: Avoid static LLVM linking for cross builds

[kernel test robot <lkp@intel.com>]

:::::: 
:::::: Manual check reason: "low confidence bisect report"
:::::: Manual check reason: "only suspicious fbc files changed"
:::::: 

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References: <20260602-tools_build_fix_zero_init_bpf_only-v2-8-c76e5250ea1c@arm.com>
TO: Leo Yan <leo.yan@arm.com>
TO: Quentin Monnet <qmo@kernel.org>
TO: Alexei Starovoitov <ast@kernel.org>
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TO: Yonghong Song <yonghong.song@linux.dev>
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TO: Lorenz Bauer <lmb@isovalent.com>
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CC: Leo Yan <leo.yan@arm.com>

Hi Leo,

kernel test robot noticed the following build warnings:

[auto build test WARNING on b93c55b4932dd7e32dca8cf34a3443cc87a02906]

url:    https://github.com/intel-lab-lkp/linux/commits/Leo-Yan/bpftool-Pass-host-flags-to-bootstrap-libbpf/20260602-231100
base:   b93c55b4932dd7e32dca8cf34a3443cc87a02906
patch link:    https://lore.kernel.org/r/20260602-tools_build_fix_zero_init_bpf_only-v2-8-c76e5250ea1c%40arm.com
patch subject: [PATCH bpf-next v2 8/8] selftests/bpf: Avoid static LLVM linking for cross builds
:::::: branch date: 6 hours ago
:::::: commit date: 6 hours ago
config: riscv-allnoconfig-bpf (https://download.01.org/0day-ci/archive/20260602/202606022207.PcDtt93e-lkp@intel.com/config)
compiler: riscv64-linux-gnu-gcc (Debian 14.2.0-19) 14.2.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20260602/202606022207.PcDtt93e-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/r/202606022207.PcDtt93e-lkp@intel.com/

All warnings (new ones prefixed by >>):

   Makefile.config:577: No elfutils/debuginfod.h found, no debuginfo server support, please install libdebuginfod-dev/elfutils-debuginfod-client-devel or equivalent
   Makefile.config:964: No libllvm 13+ found, slower source file resolution, please install llvm-devel/llvm-dev
   Makefile.config:1160: Rust is not found. Test workloads with rust are disabled.
     PERF_VERSION = 7.1.rc5.g381f7c643a0a
>> cc1: warning: '-Wformat-y2k' ignored without '-Wformat' [-Wformat-y2k]
>> cc1: warning: '-Wformat-security' ignored without '-Wformat' [-Wformat-security]
   builtin-trace.c: In function 'syscall_arg__strtoul_btf_enum':
   builtin-trace.c:967:27: error: comparison of integer expressions of different signedness: 'int' and '__u32' {aka 'unsigned int'} [-Werror=sign-compare]
     967 |         for (int i = 0; i < btf_vlen(bt); ++i, ++be) {
         |                           ^
   util/btf.c: In function '__btf_type__find_member_by_name':
   util/btf.c:19:43: error: comparison of integer expressions of different signedness: 'int' and '__u32' {aka 'unsigned int'} [-Werror=sign-compare]
      19 |         for (i = 0, m = btf_members(t); i < btf_vlen(t); i++, m++) {
         |                                           ^
   cc1: all warnings being treated as errors
   make[4]: *** [tools/build/Makefile.build:95: util/btf.o] Error 1
   make[4]: *** Waiting for unfinished jobs....
   cc1: all warnings being treated as errors
   make[3]: *** [tools/build/Makefile.build:95: builtin-trace.o] Error 1
   make[3]: *** Waiting for unfinished jobs....
   make[3]: *** [tools/build/Makefile.build:158: util] Error 2
   make[2]: *** [Makefile.perf:802: perf-util-in.o] Error 2
   make[2]: *** Waiting for unfinished jobs....
   make[2]: *** [Makefile.perf:775: perf-in.o] Error 2
   make[1]: *** [Makefile.perf:288: sub-make] Error 2

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