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 | 203 ++++++++++++++++++
.../progs/uprobe_multi_session_consumers.c | 53 +++++
2 files changed, 256 insertions(+)
create mode 100644 tools/testing/selftests/bpf/progs/uprobe_multi_session_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 b521590fdbb9..83eac954cf00 100644
--- a/tools/testing/selftests/bpf/prog_tests/uprobe_multi_test.c
+++ b/tools/testing/selftests/bpf/prog_tests/uprobe_multi_test.c
@@ -9,6 +9,7 @@
#include "uprobe_multi_session.skel.h"
#include "uprobe_multi_session_cookie.skel.h"
#include "uprobe_multi_session_recursive.skel.h"
+#include "uprobe_multi_session_consumers.skel.h"
#include "bpf/libbpf_internal.h"
#include "testing_helpers.h"
#include "../sdt.h"
@@ -739,6 +740,206 @@ static void test_session_recursive_skel_api(void)
uprobe_multi_session_recursive__destroy(skel);
}
+static int uprobe_attach(struct uprobe_multi_session_consumers *skel, int bit)
+{
+ struct bpf_program **prog = &skel->progs.uprobe_0 + bit;
+ struct bpf_link **link = &skel->links.uprobe_0 + bit;
+ LIBBPF_OPTS(bpf_uprobe_multi_opts, opts);
+
+ /*
+ * bit: 0,1 uprobe session
+ * bit: 2,3 uprobe entry
+ * bit: 4,5 uprobe return
+ */
+ opts.session = bit < 2;
+ opts.retprobe = bit == 4 || bit == 5;
+
+ *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_session_consumers *skel, int bit)
+{
+ struct bpf_link **link = &skel->links.uprobe_0 + bit;
+
+ 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_session_consumers *skel,
+ unsigned long before, unsigned long after)
+{
+ int bit;
+
+ /* detach uprobe for each unset bit in 'before' state ... */
+ for (bit = 0; bit < 6; bit++) {
+ if (test_bit(bit, before) && !test_bit(bit, after))
+ uprobe_detach(skel, bit);
+ }
+
+ /* ... and attach all new bits in 'after' state */
+ for (bit = 0; bit < 6; bit++) {
+ if (!test_bit(bit, before) && test_bit(bit, after)) {
+ if (!ASSERT_OK(uprobe_attach(skel, bit), "uprobe_attach_after"))
+ return -1;
+ }
+ }
+ return 0;
+}
+
+static void session_consumer_test(struct uprobe_multi_session_consumers *skel,
+ unsigned long before, unsigned long after)
+{
+ int err, bit;
+
+ /* 'before' is each, we attach uprobe for every set bit */
+ for (bit = 0; bit < 6; bit++) {
+ if (test_bit(bit, before)) {
+ if (!ASSERT_OK(uprobe_attach(skel, bit), "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 (bit = 0; bit < 6; bit++) {
+ const char *fmt = "BUG";
+ __u64 val = 0;
+
+ if (bit == 0) {
+ /*
+ * session with return
+ * +1 if defined in 'before'
+ * +1 if defined in 'after'
+ */
+ if (test_bit(bit, before)) {
+ val++;
+ if (test_bit(bit, after))
+ val++;
+ }
+ fmt = "bit 0 : session with return";
+ } else if (bit == 1) {
+ /*
+ * session without return
+ * +1 if defined in 'before'
+ */
+ if (test_bit(bit, before))
+ val++;
+ fmt = "bit 1 : session with NO return";
+ } else if (bit < 4) {
+ /*
+ * uprobe entry
+ * +1 if define in 'before'
+ */
+ if (test_bit(bit, before))
+ val++;
+ fmt = "bit 3/4: 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:
+ *
+ * bits: 0 (session with return) 4/5 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 & 0b110001; // is uretprobe installed
+ unsigned long exists = before & after; // did uprobe go away
+
+ if (installed && exists && test_bit(bit, after))
+ val++;
+ fmt = "bit 5/6: uretprobe";
+ }
+
+ ASSERT_EQ(skel->bss->uprobe_result[bit], val, fmt);
+ skel->bss->uprobe_result[bit] = 0;
+ }
+
+cleanup:
+ for (bit = 0; bit < 6; bit++) {
+ struct bpf_link **link = &skel->links.uprobe_0 + bit;
+
+ if (*link)
+ uprobe_detach(skel, bit);
+ }
+}
+
+static void test_session_consumers(void)
+{
+ struct uprobe_multi_session_consumers *skel;
+ int before, after;
+
+ skel = uprobe_multi_session_consumers__open_and_load();
+ if (!ASSERT_OK_PTR(skel, "uprobe_multi_session_consumers__open_and_load"))
+ return;
+
+ /*
+ * The idea of this test is to try all possible combinations of
+ * uprobes consumers attached on single function.
+ *
+ * - 1 uprobe session with return handler called
+ * - 1 uprobe session without return handler called
+ * - 2 uprobe entry consumer
+ * - 2 uprobe exit consumers
+ *
+ * The test uses 6 uprobes attached on single function, but that
+ * translates into single uprobe with 6 consumers in kernel.
+ *
+ * The before/after values present the state of attached consumers
+ * before and after the probed function:
+ *
+ * bit 0 : uprobe session with return
+ * bit 1 : uprobe session with no return
+ * bit 2,3 : uprobe entry
+ * bit 4,5 : uprobe return
+ *
+ * For example for:
+ *
+ * before = 0b10101
+ * after = 0b00110
+ *
+ * it means that before we call 'uprobe_session_consumer_test' we
+ * attach uprobes defined in 'before' value:
+ *
+ * - bit 0: uprobe session with return
+ * - bit 2: uprobe entry
+ * - bit 4: uprobe return
+ *
+ * uprobe_session_consumer_test is called and inside it we attach
+ * and detach * uprobes based on 'after' value:
+ *
+ * - bit 0: uprobe session with return is detached
+ * - bit 1: uprobe session without return is attached
+ * - bit 2: stays untouched
+ * - bit 4: uprobe return is detached
+ *
+ * uprobe_session_consumer_test returs 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 < 64; before++) {
+ for (after = 0; after < 64; after++)
+ session_consumer_test(skel, before, after);
+ }
+
+ uprobe_multi_session_consumers__destroy(skel);
+}
+
static void test_bench_attach_uprobe(void)
{
long attach_start_ns = 0, attach_end_ns = 0;
@@ -833,4 +1034,6 @@ void test_uprobe_multi_test(void)
test_session_cookie_skel_api();
if (test__start_subtest("session_cookie_recursive"))
test_session_recursive_skel_api();
+ if (test__start_subtest("session/consumers"))
+ test_session_consumers();
}
diff --git a/tools/testing/selftests/bpf/progs/uprobe_multi_session_consumers.c b/tools/testing/selftests/bpf/progs/uprobe_multi_session_consumers.c
new file mode 100644
index 000000000000..035d31a0a7f8
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/uprobe_multi_session_consumers.c
@@ -0,0 +1,53 @@
+// 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[6];
+
+SEC("uprobe.session")
+int uprobe_0(struct pt_regs *ctx)
+{
+ uprobe_result[0]++;
+ return 0;
+}
+
+SEC("uprobe.session")
+int uprobe_1(struct pt_regs *ctx)
+{
+ uprobe_result[1]++;
+ return 1;
+}
+
+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;
+}
+
+SEC("uprobe.multi")
+int uprobe_4(struct pt_regs *ctx)
+{
+ uprobe_result[4]++;
+ return 0;
+}
+
+SEC("uprobe.multi")
+int uprobe_5(struct pt_regs *ctx)
+{
+ uprobe_result[5]++;
+ return 0;
+}
--
2.45.2
