Hi,

On Sat, Oct 08, 2022 at 04:57:43PM +0800, kernel test robot wrote: (...)

2022-10-02 10:04:53 make TARGETS=nolibc make[1]: Entering directory '/usr/src/perf_selftests-x86_64-rhel-8.3-kselftests-362aecb2d8cfad0268d6c0ae5f448e9b6eee7ffb/tools/testing/selftests/nolibc' CC nolibc-test /usr/bin/ld: /tmp/cccOWbdp.o: in function `printf': nolibc-test.c:(.text+0x369): undefined reference to `strlen' collect2: error: ld returned 1 exit status make[1]: *** [Makefile:31: nolibc-test] Error 1 make[1]: Leaving directory '/usr/src/perf_selftests-x86_64-rhel-8.3-kselftests-362aecb2d8cfad0268d6c0ae5f448e9b6eee7ffb/tools/testing/selftests/nolibc' make: *** [Makefile:155: all] Error 2 2022-10-02 10:04:53 make -C nolibc make: Entering directory '/usr/src/perf_selftests-x86_64-rhel-8.3-kselftests-362aecb2d8cfad0268d6c0ae5f448e9b6eee7ffb/tools/testing/selftests/nolibc' CC nolibc-test /usr/bin/ld: /tmp/lkp/ccP4fovP.o: in function `printf': nolibc-test.c:(.text+0x369): undefined reference to `strlen' collect2: error: ld returned 1 exit status make: *** [Makefile:31: nolibc-test] Error 1 make: Leaving directory '/usr/src/perf_selftests-x86_64-rhel-8.3-kselftests-362aecb2d8cfad0268d6c0ae5f448e9b6eee7ffb/tools/testing/selftests/nolibc' 2022-10-02 10:04:54 make quicktest=1 run_tests -C nolibc make: Entering directory '/usr/src/perf_selftests-x86_64-rhel-8.3-kselftests-362aecb2d8cfad0268d6c0ae5f448e9b6eee7ffb/tools/testing/selftests/nolibc' make: *** No rule to make target 'run_tests'. Stop. make: Leaving directory '/usr/src/perf_selftests-x86_64-rhel-8.3-kselftests-362aecb2d8cfad0268d6c0ae5f448e9b6eee7ffb/tools/testing/selftests/nolibc'

This error only happens when build with gcc-12, while gcc-11 and gcc-9 build fine. We are not sure whether this is a compiler issue or a kernel code issue, so we send this report FYI. Below link may be helpful for analysis:

https://www.spinics.net/lists/fedora-devel/msg296395.html

(...)

Many thanks for the detailed report and hints. Since we're only providing include files we don't always have the luxury of enforcing build options on the caller, so it took me quite some trial and error but I finally found a way around it. I'm sending a updated patch to Paul for merging.

Thanks again, Willy