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", _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
---
v2:
- replease CHECK_FAIL by CHECK
- fix test_tcpnotify_user failed issue
---
.../selftests/bpf/prog_tests/send_signal.c | 18 --
.../bpf/prog_tests/stacktrace_build_id_nmi.c | 4 +++-
.../selftests/bpf/test_tcpnotify_user.c| 13 ++---
3 files changed, 21 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..7043e6ded0e6 100644
--- a/tools/testing/selftests/bpf/prog_tests/send_signal.c
+++ b/tools/testing/selftests/bpf/prog_tests/send_signal.c
@@ -48,21 +48,19 @@ 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);
+ CHECK(write(pipe_c2p[1], buf, 1) != 1, "pipe_write", "err
%d\n", -errno);
/* make sure parent enabled bpf program to send_signal */
- read(pipe_p2c[0], buf, 1);
+ CHECK(read(pipe_p2c[0], buf, 1) != 1, "pipe_read", "err %d\n",
-errno);
/* 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';
+ CHECK(write(pipe_c2p[1], buf, 1) != 1, "pipe_write", "err
%d\n", -errno);
/* wait for parent notification and exit */
- read(pipe_p2c[0], buf, 1);
+ CHECK(read(pipe_p2c[0], buf, 1) != 1, "pipe_read", "err %d\n",
-errno);
close(pipe_c2p[1]);
close(pipe_p2c[0]);
@@ -99,7 +97,7 @@ static void test_send_signal_common(struct perf_event_attr
*attr,
}
/* wait until child signal handler installed */
- read(pipe_c2p[0], buf, 1);
+ CHECK(read(pipe_c2p[0], buf, 1) != 1, "pipe_read", "err %d\n", -errno);
/* trigger the bpf send_signal */
skel->bss->pid = pid;
@@ -107,7 +105,7 @@ 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);
+ CHECK(write(pipe_p2c[1], buf, 1) != 1, "pipe_write", "err %d\n",
-errno);
/* wait for result */
err = read(pipe_c2p[0], buf, 1);
@@ -121,7 +119,7 @@ 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);
+ CHECK(write(pipe_p2c[1], buf, 1) != 1, "pipe_write", "err %d\n",
-errno);
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..11a769e18f5d 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
@@ -6,11 +6,13 @@ static __u64 read_perf_max_sample_freq(void)
{
__u64 sample_freq = 5000; /* fallback to 5000 on error */
FILE *f;
+ __u32 duration = 0;
f = fopen("/proc/sys/kernel/perf_event_max_sample_rate", "r");
