aboutsummaryrefslogtreecommitdiff
path: root/tools
diff options
context:
space:
mode:
authorEduard Zingerman2024-03-06 12:45:19 +0200
committerAndrii Nakryiko2024-03-06 15:18:15 -0800
commitc8617e8bcf8d1ef357fadf5c96bd86b9952fb93f (patch)
tree98d73393511d70d2f7712f98ae0ace043330d0bc /tools
parent5bab7a277ca8d4ef377a50a6678577b5bd7f74d8 (diff)
selftests/bpf: Utility functions to capture libbpf log in test_progs
Several test_progs tests already capture libbpf log in order to check for some expected output, e.g bpf_tcp_ca.c, kfunc_dynptr_param.c, log_buf.c and a few others. This commit provides a, hopefully, simple API to capture libbpf log w/o necessity to define new print callback in each test: /* Creates a global memstream capturing INFO and WARN level output * passed to libbpf_print_fn. * Returns 0 on success, negative value on failure. * On failure the description is printed using PRINT_FAIL and * current test case is marked as fail. */ int start_libbpf_log_capture(void) /* Destroys global memstream created by start_libbpf_log_capture(). * Returns a pointer to captured data which has to be freed. * Returned buffer is null terminated. */ char *stop_libbpf_log_capture(void) The intended usage is as follows: if (start_libbpf_log_capture()) return; use_libbpf(); char *log = stop_libbpf_log_capture(); ASSERT_HAS_SUBSTR(log, "... expected ...", "expected some message"); free(log); As a safety measure, free(start_libbpf_log_capture()) is invoked in the epilogue of the test_progs.c:run_one_test(). Signed-off-by: Eduard Zingerman <eddyz87@gmail.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20240306104529.6453-6-eddyz87@gmail.com
Diffstat (limited to 'tools')
-rw-r--r--tools/testing/selftests/bpf/test_progs.c59
-rw-r--r--tools/testing/selftests/bpf/test_progs.h3
2 files changed, 62 insertions, 0 deletions
diff --git a/tools/testing/selftests/bpf/test_progs.c b/tools/testing/selftests/bpf/test_progs.c
index 808550986f30..89ff704e9dad 100644
--- a/tools/testing/selftests/bpf/test_progs.c
+++ b/tools/testing/selftests/bpf/test_progs.c
@@ -683,11 +683,69 @@ static const struct argp_option opts[] = {
{},
};
+static FILE *libbpf_capture_stream;
+
+static struct {
+ char *buf;
+ size_t buf_sz;
+} libbpf_output_capture;
+
+/* Creates a global memstream capturing INFO and WARN level output
+ * passed to libbpf_print_fn.
+ * Returns 0 on success, negative value on failure.
+ * On failure the description is printed using PRINT_FAIL and
+ * current test case is marked as fail.
+ */
+int start_libbpf_log_capture(void)
+{
+ if (libbpf_capture_stream) {
+ PRINT_FAIL("%s: libbpf_capture_stream != NULL\n", __func__);
+ return -EINVAL;
+ }
+
+ libbpf_capture_stream = open_memstream(&libbpf_output_capture.buf,
+ &libbpf_output_capture.buf_sz);
+ if (!libbpf_capture_stream) {
+ PRINT_FAIL("%s: open_memstream failed errno=%d\n", __func__, errno);
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+/* Destroys global memstream created by start_libbpf_log_capture().
+ * Returns a pointer to captured data which has to be freed.
+ * Returned buffer is null terminated.
+ */
+char *stop_libbpf_log_capture(void)
+{
+ char *buf;
+
+ if (!libbpf_capture_stream)
+ return NULL;
+
+ fputc(0, libbpf_capture_stream);
+ fclose(libbpf_capture_stream);
+ libbpf_capture_stream = NULL;
+ /* get 'buf' after fclose(), see open_memstream() documentation */
+ buf = libbpf_output_capture.buf;
+ memset(&libbpf_output_capture, 0, sizeof(libbpf_output_capture));
+ return buf;
+}
+
static int libbpf_print_fn(enum libbpf_print_level level,
const char *format, va_list args)
{
+ if (libbpf_capture_stream && level != LIBBPF_DEBUG) {
+ va_list args2;
+
+ va_copy(args2, args);
+ vfprintf(libbpf_capture_stream, format, args2);
+ }
+
if (env.verbosity < VERBOSE_VERY && level == LIBBPF_DEBUG)
return 0;
+
vfprintf(stdout, format, args);
return 0;
}
@@ -1081,6 +1139,7 @@ static void run_one_test(int test_num)
cleanup_cgroup_environment();
stdio_restore();
+ free(stop_libbpf_log_capture());
dump_test_log(test, state, false, false, NULL);
}
diff --git a/tools/testing/selftests/bpf/test_progs.h b/tools/testing/selftests/bpf/test_progs.h
index 80df51244886..0ba5a20b19ba 100644
--- a/tools/testing/selftests/bpf/test_progs.h
+++ b/tools/testing/selftests/bpf/test_progs.h
@@ -397,6 +397,9 @@ int test__join_cgroup(const char *path);
system(cmd); \
})
+int start_libbpf_log_capture(void);
+char *stop_libbpf_log_capture(void);
+
static inline __u64 ptr_to_u64(const void *ptr)
{
return (__u64) (unsigned long) ptr;