Merge branch 'vsock-test-tests-for-memory-leaks'

Michal Luczaj says:

====================
vsock/test: Tests for memory leaks

Series adds tests for recently fixed memory leaks[1]:

commit d7b0ff5 ("virtio/vsock: Fix accept_queue memory leak")
commit fbf7085 ("vsock: Fix sk_error_queue memory leak")
commit 60cf620 ("virtio/vsock: Improve MSG_ZEROCOPY error handling")

Patch 1 is a non-functional preparatory cleanup.
Patch 2 is a test suite extension for picking specific tests.
Patch 3 explains the need of kmemleak scans.
Patch 4 adapts utility functions to handle MSG_ZEROCOPY.
Patches 5-6-7 add the tests.

NOTE: Test in the last patch ("vsock/test: Add test for MSG_ZEROCOPY
completion memory leak") may stop working even before this series is
merged. See changes proposed in [2]. The failslab variant would be
unaffected.

[1] https://lore.kernel.org/[email protected]
[2] https://lore.kernel.org/CANn89i+oL+qoPmbbGvE_RT3_3OWgeck7cCPcTafeehKrQZ8kyw@mail.gmail.com

v3: https://lore.kernel.org/[email protected]
v2: https://lore.kernel.org/[email protected]
v1: https://lore.kernel.org/[email protected]
====================

Link: https://patch.msgid.link/[email protected]
Signed-off-by: Jakub Kicinski <[email protected]>

Author: kuba-moo

tools/testing/vsock/README

@@ -36,6 +36,21 @@ Invoke test binaries in both directions as follows:
                        --control-port=1234 \
                        --peer-cid=3
 
+Some tests are designed to produce kernel memory leaks. Leaks detection,
+however, is deferred to Kernel Memory Leak Detector. It is recommended to enable
+kmemleak (CONFIG_DEBUG_KMEMLEAK=y) and explicitly trigger a scan after each test
+suite run, e.g.
+
+  # echo clear > /sys/kernel/debug/kmemleak
+  # $TEST_BINARY ...
+  # echo "wait for any grace periods" && sleep 2
+  # echo scan > /sys/kernel/debug/kmemleak
+  # echo "wait for kmemleak" && sleep 5
+  # echo scan > /sys/kernel/debug/kmemleak
+  # cat /sys/kernel/debug/kmemleak
+
+For more information see Documentation/dev-tools/kmemleak.rst.
+
 vsock_perf utility
 -------------------
 'vsock_perf' is a simple tool to measure vsock performance. It works in

tools/testing/vsock/util.c

@@ -401,7 +401,7 @@ void recv_buf(int fd, void *buf, size_t len, int flags, ssize_t expected_ret)
  */
 void send_byte(int fd, int expected_ret, int flags)
 {
-	const uint8_t byte = 'A';
+	static const uint8_t byte = 'A';
 
 	send_buf(fd, &byte, sizeof(byte), flags, expected_ret);
 }
@@ -420,7 +420,7 @@ void recv_byte(int fd, int expected_ret, int flags)
 	recv_buf(fd, &byte, sizeof(byte), flags, expected_ret);
 
 	if (byte != 'A') {
-		fprintf(stderr, "unexpected byte read %c\n", byte);
+		fprintf(stderr, "unexpected byte read 0x%02x\n", byte);
 		exit(EXIT_FAILURE);
 	}
 }
@@ -486,8 +486,7 @@ void list_tests(const struct test_case *test_cases)
 	exit(EXIT_FAILURE);
 }
 
-void skip_test(struct test_case *test_cases, size_t test_cases_len,
-	       const char *test_id_str)
+static unsigned long parse_test_id(const char *test_id_str, size_t test_cases_len)
 {
 	unsigned long test_id;
 	char *endptr = NULL;
@@ -505,9 +504,35 @@ void skip_test(struct test_case *test_cases, size_t test_cases_len,
 		exit(EXIT_FAILURE);
 	}
 
+	return test_id;
+}
+
+void skip_test(struct test_case *test_cases, size_t test_cases_len,
+	       const char *test_id_str)
+{
+	unsigned long test_id = parse_test_id(test_id_str, test_cases_len);
 	test_cases[test_id].skip = true;
 }
 
+void pick_test(struct test_case *test_cases, size_t test_cases_len,
+	       const char *test_id_str)
+{
+	static bool skip_all = true;
+	unsigned long test_id;
+
+	if (skip_all) {
+		unsigned long i;
+
+		for (i = 0; i < test_cases_len; ++i)
+			test_cases[i].skip = true;
+
+		skip_all = false;
+	}
+
+	test_id = parse_test_id(test_id_str, test_cases_len);
+	test_cases[test_id].skip = false;
+}
+
 unsigned long hash_djb2(const void *data, size_t len)
 {
 	unsigned long hash = 5381;

tools/testing/vsock/util.h

@@ -62,6 +62,8 @@ void run_tests(const struct test_case *test_cases,
 void list_tests(const struct test_case *test_cases);
 void skip_test(struct test_case *test_cases, size_t test_cases_len,
 	       const char *test_id_str);
+void pick_test(struct test_case *test_cases, size_t test_cases_len,
+	       const char *test_id_str);
 unsigned long hash_djb2(const void *data, size_t len);
 size_t iovec_bytes(const struct iovec *iov, size_t iovnum);
 unsigned long iovec_hash_djb2(const struct iovec *iov, size_t iovnum);