Adding test that attached/detaches multiple consumers on
single uprobe and verifies all were hit as expected.
Signed-off-by: Jiri Olsa <jolsa@xxxxxxxxxx>
---
.../bpf/prog_tests/uprobe_multi_test.c | 211 +++++++++++++++++-
.../bpf/progs/uprobe_multi_consumers.c | 39 ++++
2 files changed, 249 insertions(+), 1 deletion(-)
create mode 100644 tools/testing/selftests/bpf/progs/uprobe_multi_consumers.c
diff --git a/tools/testing/selftests/bpf/prog_tests/uprobe_multi_test.c b/tools/testing/selftests/bpf/prog_tests/uprobe_multi_test.c
index da8873f24a53..5228085c2240 100644
--- a/tools/testing/selftests/bpf/prog_tests/uprobe_multi_test.c
+++ b/tools/testing/selftests/bpf/prog_tests/uprobe_multi_test.c
@@ -6,6 +6,7 @@
#include "uprobe_multi.skel.h"
#include "uprobe_multi_bench.skel.h"
#include "uprobe_multi_usdt.skel.h"
+#include "uprobe_multi_consumers.skel.h"
#include "bpf/libbpf_internal.h"
#include "testing_helpers.h"
#include "../sdt.h"
@@ -581,7 +582,7 @@ static void attach_uprobe_fail_refctr(struct uprobe_multi *skel)
goto cleanup;
/*
- * We attach to 3 uprobes on 2 functions so 2 uprobes share single function,
+ * We attach to 3 uprobes on 2 functions, so 2 uprobes share single function,
* but with different ref_ctr_offset which is not allowed and results in fail.
*/
offsets[0] = tmp_offsets[0]; /* uprobe_multi_func_1 */
@@ -722,6 +723,212 @@ static void test_link_api(void)
__test_link_api(child);
}
+static struct bpf_program *
+get_program(struct uprobe_multi_consumers *skel, int prog)
+{
+ switch (prog) {
+ case 0:
+ return skel->progs.uprobe_0;
+ case 1:
+ return skel->progs.uprobe_1;
+ case 2:
+ return skel->progs.uprobe_2;
+ case 3:
+ return skel->progs.uprobe_3;
+ default:
+ ASSERT_FAIL("get_program");
+ return NULL;
+ }
+}
+
+static struct bpf_link **
+get_link(struct uprobe_multi_consumers *skel, int link)
+{
+ switch (link) {
+ case 0:
+ return &skel->links.uprobe_0;
+ case 1:
+ return &skel->links.uprobe_1;
+ case 2:
+ return &skel->links.uprobe_2;
+ case 3:
+ return &skel->links.uprobe_3;
+ default:
+ ASSERT_FAIL("get_link");
+ return NULL;
+ }
+}
+
+static int uprobe_attach(struct uprobe_multi_consumers *skel, int idx)
+{
+ struct bpf_program *prog = get_program(skel, idx);
+ struct bpf_link **link = get_link(skel, idx);
+ LIBBPF_OPTS(bpf_uprobe_multi_opts, opts);
+
+ /*
+ * bit/prog: 0,1 uprobe entry
+ * bit/prog: 2,3 uprobe return
+ */
+ opts.retprobe = idx == 2 || idx == 3;
+
+ *link = bpf_program__attach_uprobe_multi(prog, 0, "/proc/self/exe",
+ "uprobe_session_consumer_test",
+ &opts);
+ if (!ASSERT_OK_PTR(*link, "bpf_program__attach_uprobe_multi"))
+ return -1;
+ return 0;
+}
+
+static void uprobe_detach(struct uprobe_multi_consumers *skel, int idx)
+{
+ struct bpf_link **link = get_link(skel, idx);
+
+ bpf_link__destroy(*link);
+ *link = NULL;
+}
+
+static bool test_bit(int bit, unsigned long val)
+{
+ return val & (1 << bit);
+}
+
+noinline int
+uprobe_session_consumer_test(struct uprobe_multi_consumers *skel,
+ unsigned long before, unsigned long after)
+{
+ int idx;
+
+ /* detach uprobe for each unset programs in 'before' state ... */
+ for (idx = 0; idx < 4; idx++) {
+ if (test_bit(idx, before) && !test_bit(idx, after))
+ uprobe_detach(skel, idx);
+ }
+
+ /* ... and attach all new programs in 'after' state */
+ for (idx = 0; idx < 4; idx++) {
+ if (!test_bit(idx, before) && test_bit(idx, after)) {
+ if (!ASSERT_OK(uprobe_attach(skel, idx), "uprobe_attach_after"))
+ return -1;
+ }
+ }
+ return 0;
+}
+
+static void session_consumer_test(struct uprobe_multi_consumers *skel,
+ unsigned long before, unsigned long after)
+{
+ int err, idx;
+
+ printf("session_consumer_test before %lu after %lu\n", before, after);
+
+ /* 'before' is each, we attach uprobe for every set idx */
+ for (idx = 0; idx < 4; idx++) {
+ if (test_bit(idx, before)) {
+ if (!ASSERT_OK(uprobe_attach(skel, idx), "uprobe_attach_before"))
+ goto cleanup;
+ }
+ }
+
+ err = uprobe_session_consumer_test(skel, before, after);
+ if (!ASSERT_EQ(err, 0, "uprobe_session_consumer_test"))
+ goto cleanup;
+
+ for (idx = 0; idx < 4; idx++) {
+ const char *fmt = "BUG";
+ __u64 val = 0;
+
+ if (idx < 2) {
+ /*
+ * uprobe entry
+ * +1 if define in 'before'
+ */
+ if (test_bit(idx, before))
+ val++;
+ fmt = "prog 0/1: uprobe";
+ } else {
+ /* uprobe return is tricky ;-)
+ *
+ * to trigger uretprobe consumer, the uretprobe needs to be installed,
+ * which means one of the 'return' uprobes was alive when probe was hit:
+ *
+ * idxs: 2/3 uprobe return in 'installed' mask
+ *
+ * in addition if 'after' state removes everything that was installed in
+ * 'before' state, then uprobe kernel object goes away and return uprobe
+ * is not installed and we won't hit it even if it's in 'after' state.
+ */
+ unsigned long installed = before & 0b1100; // is uretprobe installed
+ unsigned long exists = before & after; // did uprobe go away
+
+ if (installed && exists && test_bit(idx, after))
+ val++;
+ fmt = "idx 2/3: uretprobe";
+ }
+
+ ASSERT_EQ(skel->bss->uprobe_result[idx], val, fmt);
+ skel->bss->uprobe_result[idx] = 0;
+ }
+
+cleanup:
+ for (idx = 0; idx < 4; idx++)
+ uprobe_detach(skel, idx);
+}
+
+static void test_consumers(void)
+{
+ struct uprobe_multi_consumers *skel;
+ int before, after;
+
+ skel = uprobe_multi_consumers__open_and_load();
+ if (!ASSERT_OK_PTR(skel, "uprobe_multi_consumers__open_and_load"))
+ return;
+
+ /*
+ * The idea of this test is to try all possible combinations of
+ * uprobes consumers attached on single function.
+ *
+ * - 2 uprobe entry consumer
+ * - 2 uprobe exit consumers
+ *
+ * The test uses 4 uprobes attached on single function, but that
+ * translates into single uprobe with 4 consumers in kernel.
+ *
+ * The before/after values present the state of attached consumers
+ * before and after the probed function:
+ *
+ * bit/prog 0,1 : uprobe entry
+ * bit/prog 2,3 : uprobe return
+ *
+ * For example for:
+ *
+ * before = 0b0101
+ * after = 0b0110
+ *
+ * it means that before we call 'uprobe_session_consumer_test' we
+ * attach uprobes defined in 'before' value:
+ *
+ * - bit/prog 0: uprobe entry
+ * - bit/prog 2: uprobe return
+ *
+ * uprobe_session_consumer_test is called and inside it we attach
+ * and detach * uprobes based on 'after' value:
+ *
+ * - bit/prog 0: stays untouched
+ * - bit/prog 2: uprobe return is detached
+ *
+ * uprobe_session_consumer_test returns and we check counters values
+ * increased by bpf programs on each uprobe to match the expected
+ * count based on before/after bits.
+ */
+
+ for (before = 0; before < 16; before++) {
+ for (after = 0; after < 16; after++)
+ session_consumer_test(skel, before, after);
+ }
+
+ uprobe_multi_consumers__destroy(skel);
+}
+
static void test_bench_attach_uprobe(void)
{
long attach_start_ns = 0, attach_end_ns = 0;
@@ -812,4 +1019,6 @@ void test_uprobe_multi_test(void)
test_attach_api_fails();
if (test__start_subtest("attach_uprobe_fails"))
test_attach_uprobe_fails();
+ if (test__start_subtest("consumers"))
+ test_consumers();
}
diff --git a/tools/testing/selftests/bpf/progs/uprobe_multi_consumers.c b/tools/testing/selftests/bpf/progs/uprobe_multi_consumers.c
new file mode 100644
index 000000000000..7e0fdcbbd242
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/uprobe_multi_consumers.c
@@ -0,0 +1,39 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/bpf.h>
+#include <bpf/bpf_helpers.h>
+#include <bpf/bpf_tracing.h>
+#include <stdbool.h>
+#include "bpf_kfuncs.h"
+#include "bpf_misc.h"
+
+char _license[] SEC("license") = "GPL";
+
+__u64 uprobe_result[4];
+
+SEC("uprobe.multi")
+int uprobe_0(struct pt_regs *ctx)
+{
+ uprobe_result[0]++;
+ return 0;
+}
+
+SEC("uprobe.multi")
+int uprobe_1(struct pt_regs *ctx)
+{
+ uprobe_result[1]++;
+ return 0;
+}
+
+SEC("uprobe.multi")
+int uprobe_2(struct pt_regs *ctx)
+{
+ uprobe_result[2]++;
+ return 0;
+}
+
+SEC("uprobe.multi")
+int uprobe_3(struct pt_regs *ctx)
+{
+ uprobe_result[3]++;
+ return 0;
+}
--
2.45.2
