On 4/11/21 4:12 AM, Sedat Dilek wrote:
On Sat, Apr 10, 2021 at 6:49 PM Yonghong Song <yhs@xxxxxx> wrote:With clang compiler: make -j60 LLVM=1 LLVM_IAS=1 <=== compile kernel make -j60 -C tools/testing/selftests/bpf LLVM=1 LLVM_IAS=1 Some linker flags are not used/effective for some binaries and we have warnings like: warning: -lelf: 'linker' input unused [-Wunused-command-line-argument] We also have warnings like: .../selftests/bpf/prog_tests/ns_current_pid_tgid.c:74:57: note: treat the string as an argument to avoid this if (CHECK(waitpid(cpid, &wstatus, 0) == -1, "waitpid", strerror(errno))) ^ "%s", .../selftests/bpf/test_progs.h:129:35: note: expanded from macro 'CHECK' _CHECK(condition, tag, duration, format) ^ .../selftests/bpf/test_progs.h:108:21: note: expanded from macro '_CHECK' fprintf(stdout, ##format); \ ^ Let us add proper compilation flags to silence the above two kinds of warnings. Signed-off-by: Yonghong Song <yhs@xxxxxx> --- tools/testing/selftests/bpf/Makefile | 2 ++ 1 file changed, 2 insertions(+) diff --git a/tools/testing/selftests/bpf/Makefile b/tools/testing/selftests/bpf/Makefile index bbd61cc3889b..a9c0a64a4c49 100644 --- a/tools/testing/selftests/bpf/Makefile +++ b/tools/testing/selftests/bpf/Makefile @@ -24,6 +24,8 @@ SAN_CFLAGS ?= CFLAGS += -g -Og -rdynamic -Wall $(GENFLAGS) $(SAN_CFLAGS) \ -I$(CURDIR) -I$(INCLUDE_DIR) -I$(GENDIR) -I$(LIBDIR) \ -I$(TOOLSINCDIR) -I$(APIDIR) -I$(OUTPUT) \ + -Wno-unused-command-line-argument \ + -Wno-format-security \Are both compliler flags available for GCC (I simply don't know or have checked)?
Good question. gcc/g++ (8.4.1) does not complain these two flags and I assume they are okay as well. But further digging shows gcc only support -W[no-]format-security https://gcc.gnu.org/onlinedocs/gcc/Warning-Options.html and does not support -Wno-unused-command-line-argument. gcc/g++ simply just ignored it. I will make -Wno-unused-command-line-argument for clang only in v2. Thanks for catching this.
- Sedat --Dbpf_prog_load=bpf_prog_test_load \ -Dbpf_load_program=bpf_test_load_program LDLIBS += -lcap -lelf -lz -lrt -lpthread -- 2.30.2
