tests: assert pathname and flags when calling open()

With this change the wrappers for mock and friends are able to take an
optional io_mock_fallback_open_state struct to assert expected pathnames
and flags whenever an open operation is called.

Based partially on https://review.coreboot.org/c/flashrom/+/62319/5

BUG=b:227404721,b:217629892,b:215255210
TEST=./test_build.sh; FEATURES=test emerge-amd64-generic flashrom
BRANCH=none

Signed-off-by: Daniel Campello <campello@chromium.org>
Co-Author: Edward O'Callaghan <quasisec@google.com>
Change-Id: Ib46ca5b854c8453ec02ae09f3151cd4d25f988eb
Reviewed-on: https://review.coreboot.org/c/flashrom/+/63227
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Anastasia Klimchuk <aklm@chromium.org>

tests/io_mock.c

@@ -14,12 +14,15 @@
  * GNU General Public License for more details.
  */
 
+#include <include/test.h>
 #include "io_mock.h"
 
 static const struct io_mock *current_io = NULL;
 
 void io_mock_register(const struct io_mock *io)
 {
+	/* A test can either register its own mock open function or fallback_open_state. */
+	assert_true(io == NULL || io->open == NULL || io->fallback_open_state == NULL);
 	current_io = io;
 }
 

tests/io_mock.h

@@ -60,6 +60,15 @@ struct pci_dev {
 /* Always return success for tests. */
 #define S_ISREG(x) 0
 
+/* Maximum number of open calls to mock. This number is arbitrary. */
+#define MAX_MOCK_OPEN 4
+
+struct io_mock_fallback_open_state {
+	unsigned int noc;
+	const char *paths[MAX_MOCK_OPEN];
+	int flags[MAX_MOCK_OPEN];
+};
+
 struct io_mock {
 	void *state;
 
@@ -105,6 +114,12 @@ struct io_mock {
 	size_t (*fread)(void *state, void *buf, size_t size, size_t len, FILE *fp);
 	int (*fprintf)(void *state, FILE *fp, const char *fmt, va_list args);
 	int (*fclose)(void *state, FILE *fp);
+
+	/*
+	 * An alternative to custom open mock. A test can either register its
+	 * own mock open function or fallback_open_state.
+	 */
+	struct io_mock_fallback_open_state *fallback_open_state;
 };
 
 void io_mock_register(const struct io_mock *io);

tests/lifecycle.c

@@ -370,13 +370,6 @@ void linux_spi_probe_lifecycle_test_success(void **state)
 #endif
 }
 
-static int realtek_mst_open(void *state, const char *pathname, int flags)
-{
-	assert_string_equal(pathname, "/dev/i2c-254");
-	assert_int_equal(flags & O_RDWR, O_RDWR);
-	return MOCK_FD;
-}
-
 static int realtek_mst_ioctl(void *state, int fd, unsigned long request, va_list args)
 {
 	assert_int_equal(fd, MOCK_FD);
@@ -406,11 +399,16 @@ static int realtek_mst_write(void *state, int fd, const void *buf, size_t sz)
 void realtek_mst_basic_lifecycle_test_success(void **state)
 {
 #if CONFIG_REALTEK_MST_I2C_SPI == 1
+	static struct io_mock_fallback_open_state realtek_mst_fallback_open_state = {
+		.noc = 0,
+		.paths = { "/dev/i2c-254", NULL },
+		.flags = { O_RDWR },
+	};
 	const struct io_mock realtek_mst_io = {
-		.open = realtek_mst_open,
 		.ioctl = realtek_mst_ioctl,
 		.read = realtek_mst_read,
 		.write = realtek_mst_write,
+		.fallback_open_state = &realtek_mst_fallback_open_state,
 	};
 	io_mock_register(&realtek_mst_io);
 

tests/tests.c

@@ -74,28 +74,43 @@ uint8_t __wrap_sio_read(uint16_t port, uint8_t reg)
 	return (uint8_t)mock();
 }
 
+static int mock_open(const char *pathname, int flags)
+{
+	if (get_io() && get_io()->open)
+		return get_io()->open(get_io()->state, pathname, flags);
+
+	if (get_io() && get_io()->fallback_open_state) {
+		struct io_mock_fallback_open_state *io_state;
+		unsigned int open_state_flags;
+
+		io_state = get_io()->fallback_open_state;
+		assert_true(io_state->noc < MAX_MOCK_OPEN);
+		assert_non_null(io_state->paths[io_state->noc]);
+		assert_string_equal(pathname, io_state->paths[io_state->noc]);
+		open_state_flags = io_state->flags[io_state->noc];
+		assert_int_equal(flags & open_state_flags, open_state_flags);
+		io_state->noc++; // proceed to the next path upon next call.
+	}
+
+	return MOCK_FD;
+}
+
 int __wrap_open(const char *pathname, int flags)
 {
 	LOG_ME;
-	if (get_io() && get_io()->open)
+	return mock_open(pathname, flags);
-		return get_io()->open(get_io()->state, pathname, flags);
-	return MOCK_FD;
 }
 
 int __wrap_open64(const char *pathname, int flags)
 {
 	LOG_ME;
-	if (get_io() && get_io()->open)
+	return mock_open(pathname, flags);
-		return get_io()->open(get_io()->state, pathname, flags);
-	return MOCK_FD;
 }
 
 int __wrap___open64_2(const char *pathname, int flags)
 {
 	LOG_ME;
-	if (get_io() && get_io()->open)
+	return mock_open(pathname, flags);
-		return get_io()->open(get_io()->state, pathname, flags);
-	return MOCK_FD;
 }
 
 int __wrap_ioctl(int fd, unsigned long int request, ...)