Clang compiler version: 12.0.0
The following warning appears during the selftests/bpf compilation:
prog_tests/send_signal.c:51:3: warning: ignoring return value of ‘write’,
declared with attribute warn_unused_result [-Wunused-result]
51 | write(pipe_c2p[1], buf, 1);
| ^~~~~~~~~~~~~~~~~~~~~~~~~~
prog_tests/send_signal.c:54:3: warning: ignoring return value of ‘read’,
declared with attribute warn_unused_result [-Wunused-result]
54 | read(pipe_p2c[0], buf, 1);
| ^~~~~~~~~~~~~~~~~~~~~~~~~
......
prog_tests/stacktrace_build_id_nmi.c:13:2: warning: ignoring return value
of ‘fscanf’,declared with attribute warn_unused_result [-Wunused-resul]
13 | fscanf(f, "%llu", &sample_freq);
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
test_tcpnotify_user.c:133:2: warning:ignoring return value of ‘system’,
declared with attribute warn_unused_result [-Wunused-result]
133 | system(test_script);
| ^~~~~~~~~~~~~~~~~~~
test_tcpnotify_user.c:138:2: warning:ignoring return value of ‘system’,
declared with attribute warn_unused_result [-Wunused-result]
138 | system(test_script);
| ^~~~~~~~~~~~~~~~~~~
test_tcpnotify_user.c:143:2: warning:ignoring return value of ‘system’,
declared with attribute warn_unused_result [-Wunused-result]
143 | system(test_script);
| ^~~~~~~~~~~~~~~~~~~
Add code that fix compilation warning about ignoring return value and
handles any errors; Check return value of library`s API make the code
more secure.
Signed-off-by: Jianlin Lv <Jianlin.Lv@xxxxxxx>
---
.../selftests/bpf/prog_tests/send_signal.c | 37 ++++++++++++++-----
.../bpf/prog_tests/stacktrace_build_id_nmi.c | 3 +-
.../selftests/bpf/test_tcpnotify_user.c | 15 ++++++--
3 files changed, 41 insertions(+), 14 deletions(-)
diff --git a/tools/testing/selftests/bpf/prog_tests/send_signal.c b/tools/testing/selftests/bpf/prog_tests/send_signal.c
index 504abb7bfb95..7a5272e4e810 100644
--- a/tools/testing/selftests/bpf/prog_tests/send_signal.c
+++ b/tools/testing/selftests/bpf/prog_tests/send_signal.c
@@ -48,22 +48,31 @@ static void test_send_signal_common(struct perf_event_attr *attr,
close(pipe_p2c[1]); /* close write */
/* notify parent signal handler is installed */
- write(pipe_c2p[1], buf, 1);
+ if (CHECK_FAIL(write(pipe_c2p[1], buf, 1) != 1)) {
+ perror("Child: write pipe error");
+ goto close_out;
+ }
/* make sure parent enabled bpf program to send_signal */
- read(pipe_p2c[0], buf, 1);
+ if (CHECK_FAIL(read(pipe_p2c[0], buf, 1) != 1)) {
+ perror("Child: read pipe error");
+ goto close_out;
+ }
/* wait a little for signal handler */
sleep(1);
- if (sigusr1_received)
- write(pipe_c2p[1], "2", 1);
- else
- write(pipe_c2p[1], "0", 1);
+ buf[0] = sigusr1_received ? '2' : '0';
+ if (CHECK_FAIL(write(pipe_c2p[1], buf, 1) != 1)) {
+ perror("Child: write pipe error");
+ goto close_out;
+ }
/* wait for parent notification and exit */
- read(pipe_p2c[0], buf, 1);
+ if (CHECK_FAIL(read(pipe_p2c[0], buf, 1) != 1))
+ perror("Child: read pipe error");
+close_out:
close(pipe_c2p[1]);
close(pipe_p2c[0]);
exit(0);
@@ -99,7 +108,11 @@ static void test_send_signal_common(struct perf_event_attr *attr,
}
/* wait until child signal handler installed */
- read(pipe_c2p[0], buf, 1);
+ if (CHECK_FAIL(read(pipe_c2p[0], buf, 1) != 1)) {
+ perror("Parent: read pipe error");
+ goto disable_pmu;
+ }
+
/* trigger the bpf send_signal */
skel->bss->pid = pid;
@@ -107,7 +120,10 @@ static void test_send_signal_common(struct perf_event_attr *attr,
skel->bss->signal_thread = signal_thread;
/* notify child that bpf program can send_signal now */
- write(pipe_p2c[1], buf, 1);
+ if (CHECK_FAIL(write(pipe_p2c[1], buf, 1) != 1)) {
+ perror("Parent: write pipe error");
+ goto disable_pmu;
+ }
/* wait for result */
err = read(pipe_c2p[0], buf, 1);
@@ -121,7 +137,8 @@ static void test_send_signal_common(struct perf_event_attr *attr,
CHECK(buf[0] != '2', test_name, "incorrect result\n");
/* notify child safe to exit */
- write(pipe_p2c[1], buf, 1);
+ if (CHECK_FAIL(write(pipe_p2c[1], buf, 1) != 1))
+ perror("Parent: write pipe error");
disable_pmu:
close(pmu_fd);
diff --git a/tools/testing/selftests/bpf/prog_tests/stacktrace_build_id_nmi.c b/tools/testing/selftests/bpf/prog_tests/stacktrace_build_id_nmi.c
index f002e3090d92..a27de3d46e58 100644
--- a/tools/testing/selftests/bpf/prog_tests/stacktrace_build_id_nmi.c
+++ b/tools/testing/selftests/bpf/prog_tests/stacktrace_build_id_nmi.c
@@ -10,7 +10,8 @@ static __u64 read_perf_max_sample_freq(void)
f = fopen("/proc/sys/kernel/perf_event_max_sample_rate", "r");
if (f == NULL)
return sample_freq;
- fscanf(f, "%llu", &sample_freq);
+ if (CHECK_FAIL(fscanf(f, "%llu", &sample_freq) != 1))
+ perror("Get max sample rate fail, return default value: 5000\n");
fclose(f);
return sample_freq;
}
diff --git a/tools/testing/selftests/bpf/test_tcpnotify_user.c b/tools/testing/selftests/bpf/test_tcpnotify_user.c
index f9765ddf0761..869e28c92d73 100644
--- a/tools/testing/selftests/bpf/test_tcpnotify_user.c
+++ b/tools/testing/selftests/bpf/test_tcpnotify_user.c
@@ -130,17 +130,26 @@ int main(int argc, char **argv)
sprintf(test_script,
"iptables -A INPUT -p tcp --dport %d -j DROP",
TESTPORT);
- system(test_script);
+ if (system(test_script)) {
+ printf("FAILED: execute command: %s\n", test_script);
+ goto err;
+ }
sprintf(test_script,
"nc 127.0.0.1 %d < /etc/passwd > /dev/null 2>&1 ",
TESTPORT);
- system(test_script);
+ if (system(test_script)) {
+ printf("FAILED: execute command: %s\n", test_script);
+ goto err;
+ }
sprintf(test_script,
"iptables -D INPUT -p tcp --dport %d -j DROP",
TESTPORT);
- system(test_script);
+ if (system(test_script)) {
+ printf("FAILED: execute command: %s\n", test_script);
+ goto err;
+ }
rv = bpf_map_lookup_elem(bpf_map__fd(global_map), &key, &g);
if (rv != 0) {
--
2.17.1
