[PATCHv9 bpf-next 12/13] selftests/bpf: Add uprobe sessions to consumer test

[Jiri Olsa <jolsa@kernel.org>]

Adding uprobe session consumers to the consumer test,
so we get the session into the test mix.

In addition scaling down the test to have just 1 uprobe
and 1 uretprobe, otherwise the test time grows and is
unsuitable for CI even with threads.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
---
 .../bpf/prog_tests/uprobe_multi_test.c        | 70 +++++++++++++------
 .../bpf/progs/uprobe_multi_consumers.c        |  6 +-
 2 files changed, 52 insertions(+), 24 deletions(-)

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 93f5cabd6d01..0a31ba2d6fb2 100644
--- a/tools/testing/selftests/bpf/prog_tests/uprobe_multi_test.c
+++ b/tools/testing/selftests/bpf/prog_tests/uprobe_multi_test.c
@@ -799,10 +799,13 @@ static int uprobe_attach(struct uprobe_multi_consumers *skel, int idx)
 		return -1;
 
 	/*
-	 * bit/prog: 0,1 uprobe entry
-	 * bit/prog: 2,3 uprobe return
+	 * bit/prog: 0 uprobe entry
+	 * bit/prog: 1 uprobe return
+	 * bit/prog: 2 uprobe session without return
+	 * bit/prog: 3 uprobe session with return
 	 */
-	opts.retprobe = idx == 2 || idx == 3;
+	opts.retprobe = idx == 1;
+	opts.session  = idx == 2 || idx == 3;
 
 	*link = bpf_program__attach_uprobe_multi(prog, 0, "/proc/self/exe",
 						"uprobe_consumer_test",
@@ -867,31 +870,55 @@ static int consumer_test(struct uprobe_multi_consumers *skel,
 		goto cleanup;
 
 	for (idx = 0; idx < 4; idx++) {
+		bool uret_stays, uret_survives;
 		const char *fmt = "BUG";
 		__u64 val = 0;
 
-		if (idx < 2) {
+		switch (idx) {
+		case 0:
 			/*
 			 * uprobe entry
 			 *   +1 if define in 'before'
 			 */
 			if (test_bit(idx, before))
 				val++;
-			fmt = "prog 0/1: uprobe";
-		} else {
+			fmt = "prog 0: uprobe";
+			break;
+		case 1:
 			/*
 			 * To trigger uretprobe consumer, the uretprobe under test either stayed from
 			 * before to after (uret_stays + test_bit) or uretprobe instance survived and
 			 * we have uretprobe active in after (uret_survives + test_bit)
 			 */
-
-			bool uret_stays = before & after & 0b1100;
-			bool uret_survives = (before & 0b1100) && (after & 0b1100) && (before & 0b0011);
+			uret_stays = before & after & 0b0110;
+			uret_survives = ((before & 0b0110) && (after & 0b0110) && (before & 0b1001));
 
 			if ((uret_stays || uret_survives) && test_bit(idx, after))
 				val++;
-
-			fmt = "idx 2/3: uretprobe";
+			fmt = "prog 1: uretprobe";
+			break;
+		case 2:
+			/*
+			 * session with return
+			 *  +1 if defined in 'before'
+			 *  +1 if defined in 'after'
+			 */
+			if (test_bit(idx, before)) {
+				val++;
+				if (test_bit(idx, after))
+					val++;
+			}
+			fmt = "prog 2: session with return";
+			break;
+		case 3:
+			/*
+			 * session without return
+			 *   +1 if defined in 'before'
+			 */
+			if (test_bit(idx, before))
+				val++;
+			fmt = "prog 3: session with NO return";
+			break;
 		}
 
 		if (!ASSERT_EQ(skel->bss->uprobe_result[idx], val, fmt))
@@ -920,8 +947,10 @@ static void test_consumers(void)
 	 * 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
+	 *  - 1 uprobe entry consumer
+	 *  - 1 uprobe exit consumer
+	 *  - 1 uprobe session with return
+	 *  - 1 uprobe session without return
 	 *
 	 * The test uses 4 uprobes attached on single function, but that
 	 * translates into single uprobe with 4 consumers in kernel.
@@ -929,25 +958,24 @@ static void test_consumers(void)
 	 * 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
+	 *  bit/prog 0 : uprobe entry
+	 *  bit/prog 1 : uprobe return
 	 *
 	 * For example for:
 	 *
-	 *   before = 0b0101
-	 *   after  = 0b0110
+	 *   before = 0b01
+	 *   after  = 0b10
 	 *
 	 * it means that before we call 'uprobe_consumer_test' we attach
 	 * uprobes defined in 'before' value:
 	 *
-	 *   - bit/prog 0: uprobe entry
-	 *   - bit/prog 2: uprobe return
+	 *   - bit/prog 1: uprobe entry
 	 *
 	 * uprobe_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
+	 *   - bit/prog 0: is detached
+	 *   - bit/prog 1: is attached
 	 *
 	 * uprobe_consumer_test returns and we check counters values increased
 	 * by bpf programs on each uprobe to match the expected count based on
diff --git a/tools/testing/selftests/bpf/progs/uprobe_multi_consumers.c b/tools/testing/selftests/bpf/progs/uprobe_multi_consumers.c
index 7e0fdcbbd242..93752bb5690b 100644
--- a/tools/testing/selftests/bpf/progs/uprobe_multi_consumers.c
+++ b/tools/testing/selftests/bpf/progs/uprobe_multi_consumers.c
@@ -24,16 +24,16 @@ int uprobe_1(struct pt_regs *ctx)
 	return 0;
 }
 
-SEC("uprobe.multi")
+SEC("uprobe.session")
 int uprobe_2(struct pt_regs *ctx)
 {
 	uprobe_result[2]++;
 	return 0;
 }
 
-SEC("uprobe.multi")
+SEC("uprobe.session")
 int uprobe_3(struct pt_regs *ctx)
 {
 	uprobe_result[3]++;
-	return 0;
+	return 1;
 }
-- 
2.47.0