selftests/bpf: Silence clang compilation warnings

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);                              \
                                  ^
The first warning can be silenced with clang option -Wno-unused-command-line-argument.
For the second warning, source codes are modified as suggested by the compiler
to silence the warning. Since gcc does not support the option
-Wno-unused-command-line-argument and the warning only happens with clang
compiler, the option -Wno-unused-command-line-argument is enabled only when
clang compiler is used.

Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210413153429.3029377-1-yhs@fb.com
This commit is contained in:
Yonghong Song 2021-04-13 08:34:29 -07:00 committed by Alexei Starovoitov
parent a22c0c81da
commit ef9985893c
3 changed files with 9 additions and 4 deletions

View File

@ -28,6 +28,11 @@ CFLAGS += -g -Og -rdynamic -Wall $(GENFLAGS) $(SAN_CFLAGS) \
-Dbpf_load_program=bpf_test_load_program
LDLIBS += -lcap -lelf -lz -lrt -lpthread
# Silence some warnings when compiled with clang
ifneq ($(LLVM),)
CFLAGS += -Wno-unused-command-line-argument
endif
# Order correspond to 'make run_tests' order
TEST_GEN_PROGS = test_verifier test_tag test_maps test_lru_map test_lpm_map test_progs \
test_verifier_log test_dev_cgroup \

View File

@ -39,7 +39,7 @@ void test_fexit_sleep(void)
goto cleanup;
cpid = clone(do_sleep, child_stack + STACK_SIZE, CLONE_FILES | SIGCHLD, fexit_skel);
if (CHECK(cpid == -1, "clone", strerror(errno)))
if (CHECK(cpid == -1, "clone", "%s\n", strerror(errno)))
goto cleanup;
/* wait until first sys_nanosleep ends and second sys_nanosleep starts */
@ -65,7 +65,7 @@ void test_fexit_sleep(void)
/* kill the thread to unwind sys_nanosleep stack through the trampoline */
kill(cpid, 9);
if (CHECK(waitpid(cpid, &wstatus, 0) == -1, "waitpid", strerror(errno)))
if (CHECK(waitpid(cpid, &wstatus, 0) == -1, "waitpid", "%s\n", strerror(errno)))
goto cleanup;
if (CHECK(WEXITSTATUS(wstatus) != 0, "exitstatus", "failed"))
goto cleanup;

View File

@ -68,10 +68,10 @@ static void test_ns_current_pid_tgid_new_ns(void)
cpid = clone(test_current_pid_tgid, child_stack + STACK_SIZE,
CLONE_NEWPID | SIGCHLD, NULL);
if (CHECK(cpid == -1, "clone", strerror(errno)))
if (CHECK(cpid == -1, "clone", "%s\n", strerror(errno)))
return;
if (CHECK(waitpid(cpid, &wstatus, 0) == -1, "waitpid", strerror(errno)))
if (CHECK(waitpid(cpid, &wstatus, 0) == -1, "waitpid", "%s\n", strerror(errno)))
return;
if (CHECK(WEXITSTATUS(wstatus) != 0, "newns_pidtgid", "failed"))