Add a test case for stacktrace with skip > 0 using a small sized
buffer. It didn't support skipping entries greater than or equal to
the size of buffer and filled the skipped part with 0.
Signed-off-by: Namhyung Kim <namhyung@xxxxxxxxxx>
---
v3)
* add pid filter
* change assert condition
.../bpf/prog_tests/stacktrace_map_skip.c | 63 +++++++++++++++++
.../selftests/bpf/progs/stacktrace_map_skip.c | 68 +++++++++++++++++++
2 files changed, 131 insertions(+)
create mode 100644 tools/testing/selftests/bpf/prog_tests/stacktrace_map_skip.c
create mode 100644 tools/testing/selftests/bpf/progs/stacktrace_map_skip.c
diff --git a/tools/testing/selftests/bpf/prog_tests/stacktrace_map_skip.c b/tools/testing/selftests/bpf/prog_tests/stacktrace_map_skip.c
new file mode 100644
index 000000000000..1932b1e0685c
--- /dev/null
+++ b/tools/testing/selftests/bpf/prog_tests/stacktrace_map_skip.c
@@ -0,0 +1,63 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <test_progs.h>
+#include "stacktrace_map_skip.skel.h"
+
+#define TEST_STACK_DEPTH 2
+
+void test_stacktrace_map_skip(void)
+{
+ struct stacktrace_map_skip *skel;
+ int stackid_hmap_fd, stackmap_fd, stack_amap_fd;
+ int err, stack_trace_len;
+
+ skel = stacktrace_map_skip__open_and_load();
+ if (!ASSERT_OK_PTR(skel, "skel_open_and_load"))
+ return;
+
+ /* find map fds */
+ stackid_hmap_fd = bpf_map__fd(skel->maps.stackid_hmap);
+ if (!ASSERT_GE(stackid_hmap_fd, 0, "stackid_hmap fd"))
+ goto out;
+
+ stackmap_fd = bpf_map__fd(skel->maps.stackmap);
+ if (!ASSERT_GE(stackmap_fd, 0, "stackmap fd"))
+ goto out;
+
+ stack_amap_fd = bpf_map__fd(skel->maps.stack_amap);
+ if (!ASSERT_GE(stack_amap_fd, 0, "stack_amap fd"))
+ goto out;
+
+ skel->bss->pid = getpid();
+
+ err = stacktrace_map_skip__attach(skel);
+ if (!ASSERT_OK(err, "skel_attach"))
+ goto out;
+
+ /* give some time for bpf program run */
+ sleep(1);
+
+ /* disable stack trace collection */
+ skel->bss->control = 1;
+
+ /* for every element in stackid_hmap, we can find a corresponding one
+ * in stackmap, and vise versa.
+ */
+ err = compare_map_keys(stackid_hmap_fd, stackmap_fd);
+ if (!ASSERT_OK(err, "compare_map_keys stackid_hmap vs. stackmap"))
+ goto out;
+
+ err = compare_map_keys(stackmap_fd, stackid_hmap_fd);
+ if (!ASSERT_OK(err, "compare_map_keys stackmap vs. stackid_hmap"))
+ goto out;
+
+ stack_trace_len = TEST_STACK_DEPTH * sizeof(__u64);
+ err = compare_stack_ips(stackmap_fd, stack_amap_fd, stack_trace_len);
+ if (!ASSERT_OK(err, "compare_stack_ips stackmap vs. stack_amap"))
+ goto out;
+
+ if (!ASSERT_EQ(skel->bss->failed, 0, "skip_failed"))
+ goto out;
+
+out:
+ stacktrace_map_skip__destroy(skel);
+}
diff --git a/tools/testing/selftests/bpf/progs/stacktrace_map_skip.c b/tools/testing/selftests/bpf/progs/stacktrace_map_skip.c
new file mode 100644
index 000000000000..2eb297df3dd6
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/stacktrace_map_skip.c
@@ -0,0 +1,68 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <vmlinux.h>
+#include <bpf/bpf_helpers.h>
+
+#define TEST_STACK_DEPTH 2
+#define TEST_MAX_ENTRIES 16384
+
+typedef __u64 stack_trace_t[TEST_STACK_DEPTH];
+
+struct {
+ __uint(type, BPF_MAP_TYPE_STACK_TRACE);
+ __uint(max_entries, TEST_MAX_ENTRIES);
+ __type(key, __u32);
+ __type(value, stack_trace_t);
+} stackmap SEC(".maps");
+
+struct {
+ __uint(type, BPF_MAP_TYPE_HASH);
+ __uint(max_entries, TEST_MAX_ENTRIES);
+ __type(key, __u32);
+ __type(value, __u32);
+} stackid_hmap SEC(".maps");
+
+struct {
+ __uint(type, BPF_MAP_TYPE_ARRAY);
+ __uint(max_entries, TEST_MAX_ENTRIES);
+ __type(key, __u32);
+ __type(value, stack_trace_t);
+} stack_amap SEC(".maps");
+
+int pid = 0;
+int control = 0;
+int failed = 0;
+
+SEC("tracepoint/sched/sched_switch")
+int oncpu(struct trace_event_raw_sched_switch *ctx)
+{
+ __u32 max_len = TEST_STACK_DEPTH * sizeof(__u64);
+ __u32 key = 0, val = 0;
+ __u64 *stack_p;
+
+ if (pid != (bpf_get_current_pid_tgid() >> 32))
+ return 0;
+
+ if (control)
+ return 0;
+
+ /* it should allow skipping whole buffer size entries */
+ key = bpf_get_stackid(ctx, &stackmap, TEST_STACK_DEPTH);
+ if ((int)key >= 0) {
+ /* The size of stackmap and stack_amap should be the same */
+ bpf_map_update_elem(&stackid_hmap, &key, &val, 0);
+ stack_p = bpf_map_lookup_elem(&stack_amap, &key);
+ if (stack_p) {
+ bpf_get_stack(ctx, stack_p, max_len, TEST_STACK_DEPTH);
+ /* it wrongly skipped all the entries and filled zero */
+ if (stack_p[0] == 0)
+ failed = 1;
+ }
+ } else {
+ /* old kernel doesn't support skipping that many entries */
+ failed = 2;
+ }
+
+ return 0;
+}
+
+char _license[] SEC("license") = "GPL";
--
2.35.1.723.g4982287a31-goog
