tests: Mock file i/o for linux_mtd and linux_spi tests

This patch adds an init-shutdown test for linux_mtd. Since
linux_mtd is using file i/o operations, those are added to the
framework and mocked.

Another driver linux_spi which is also using file i/o, got an upgrade
in this patch, and it is now reading max buffer size from sysfs (using
mocked file i/o).

A good side-effect is that linux_mtd is the first test for opaque
masters, which is great to have in preparation for a change like
CB:56103 but for opaque masters.

BUG=b:181803212
TEST=builds and ninja test

Change-Id: I73f0d6ff2ad5074add7a721ed3416230d3647e3f
Signed-off-by: Anastasia Klimchuk <aklm@chromium.org>
Reviewed-on: https://review.coreboot.org/c/flashrom/+/56413
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Nico Huber <nico.h@gmx.de>
Reviewed-by: Edward O'Callaghan <quasisec@chromium.org>

tests/init_shutdown.c

@@ -19,6 +19,8 @@
 #include "io_mock.h"
 #include "programmer.h"
 
+#define NOT_NULL ((void *)0xf000baaa)
+
 static void run_lifecycle(void **state, const struct programmer_entry *prog, const char *param)
 {
 	(void) state; /* unused */
@@ -195,16 +197,107 @@ void ene_lpc_init_and_shutdown_test_success(void **state)
 #endif
 }
 
+struct linux_mtd_io_state {
+	char *fopen_path;
+};
+
+FILE *linux_mtd_fopen(void *state, const char *pathname, const char *mode)
+{
+	struct linux_mtd_io_state *io_state = state;
+
+	io_state->fopen_path = strdup(pathname);
+
+	return NOT_NULL;
+}
+
+size_t linux_mtd_fread(void *state, void *buf, size_t size, size_t len, FILE *fp)
+{
+	struct linux_mtd_fread_mock_entry {
+		const char *path;
+		const char *data;
+	};
+	const struct linux_mtd_fread_mock_entry fread_mock_map[] = {
+		{ "/sys/class/mtd/mtd0//type",            "nor"    },
+		{ "/sys/class/mtd/mtd0//name",            "Device" },
+		{ "/sys/class/mtd/mtd0//flags",           ""       },
+		{ "/sys/class/mtd/mtd0//size",            "1024"   },
+		{ "/sys/class/mtd/mtd0//erasesize",       "512"    },
+		{ "/sys/class/mtd/mtd0//numeraseregions", "0"      },
+	};
+
+	struct linux_mtd_io_state *io_state = state;
+	unsigned int i;
+
+	if (!io_state->fopen_path)
+		return 0;
+
+	for (i = 0; i < ARRAY_SIZE(fread_mock_map); i++) {
+		const struct linux_mtd_fread_mock_entry *entry = &fread_mock_map[i];
+
+		if (!strcmp(io_state->fopen_path, entry->path)) {
+			size_t data_len = min(size * len, strlen(entry->data));
+			memcpy(buf, entry->data, data_len);
+			return data_len;
+		}
+	}
+
+	return 0;
+}
+
+int linux_mtd_fclose(void *state, FILE *fp)
+{
+	struct linux_mtd_io_state *io_state = state;
+
+	free(io_state->fopen_path);
+
+	return 0;
+}
+
+void linux_mtd_init_and_shutdown_test_success(void **state)
+{
+#if CONFIG_LINUX_MTD == 1
+	struct linux_mtd_io_state linux_mtd_io_state = { NULL };
+	const struct io_mock linux_mtd_io = {
+		.state	= &linux_mtd_io_state,
+		.fopen	= linux_mtd_fopen,
+		.fread	= linux_mtd_fread,
+		.fclose = linux_mtd_fclose,
+	};
+
+	io_mock_register(&linux_mtd_io);
+
+	run_lifecycle(state, &programmer_linux_mtd, "");
+
+	io_mock_register(NULL);
+#else
+	skip();
+#endif
+}
+
+char *linux_spi_fgets(void *state, char *buf, int len, FILE *fp)
+{
+	/* Emulate reading max buffer size from sysfs. */
+	const char *max_buf_size = "1048576";
+
+	return memcpy(buf, max_buf_size, min(len, strlen(max_buf_size) + 1));
+}
+
 void linux_spi_init_and_shutdown_test_success(void **state)
 {
 	/*
 	 * Current implementation tests a particular path of the init procedure.
-	 * There are two ways for it to succeed: reading the buffer size from sysfs
-	 * and the fallback to getpagesize(). This test does the latter (fallback to
-	 * getpagesize).
+	 * Specifically, it is reading the buffer size from sysfs.
 	 */
 #if CONFIG_LINUX_SPI == 1
+	const struct io_mock linux_spi_io = {
+		.fgets	= linux_spi_fgets,
+	};
+
+	io_mock_register(&linux_spi_io);
+
 	run_lifecycle(state, &programmer_linux_spi, "dev=/dev/null");
+
+	io_mock_register(NULL);
 #else
 	skip();
 #endif

tests/io_mock.h

@@ -31,6 +31,9 @@
 #ifndef _IO_MOCK_H_
 #define _IO_MOCK_H_
 
+/* Required for `FILE *` */
+#include <stdio.h>
+
 /* Define libusb symbols to avoid dependency on libusb.h */
 struct libusb_device_handle;
 typedef struct libusb_device_handle libusb_device_handle;
@@ -79,6 +82,12 @@ struct io_mock {
 	int (*ioctl)(void *state, int fd, unsigned long request, va_list args);
 	int (*read)(void *state, int fd, void *buf, size_t sz);
 	int (*write)(void *state, int fd, const void *buf, size_t sz);
+
+	/* Standard I/O */
+	FILE* (*fopen)(void *state, const char *pathname, const char *mode);
+	char* (*fgets)(void *state, char *buf, int len, FILE *fp);
+	size_t (*fread)(void *state, void *buf, size_t size, size_t len, FILE *fp);
+	int (*fclose)(void *state, FILE *fp);
 };
 
 void io_mock_register(const struct io_mock *io);

tests/meson.build

@@ -39,6 +39,15 @@ mocks = [
   '-Wl,--wrap=write',
   '-Wl,--wrap=fopen',
   '-Wl,--wrap=fopen64',
+  '-Wl,--wrap=stat',
+  '-Wl,--wrap=stat64',
+  '-Wl,--wrap=fread',
+  '-Wl,--wrap=fgets',
+  '-Wl,--wrap=fclose',
+  '-Wl,--wrap=feof',
+  '-Wl,--wrap=ferror',
+  '-Wl,--wrap=clearerr',
+  '-Wl,--wrap=setvbuf',
   '-Wl,--wrap=rget_io_perms',
   '-Wl,--wrap=test_outb',
   '-Wl,--wrap=test_inb',

tests/tests.c

@@ -129,15 +129,78 @@ int __wrap_read(int fd, void *buf, size_t sz)
 FILE *__wrap_fopen(const char *pathname, const char *mode)
 {
 	LOG_ME;
-	return NULL;
+	if (current_io && current_io->fopen)
+		return current_io->fopen(current_io->state, pathname, mode);
+	return (void *)MOCK_HANDLE;
 }
 
 FILE *__wrap_fopen64(const char *pathname, const char *mode)
 {
 	LOG_ME;
+	if (current_io && current_io->fopen)
+		return current_io->fopen(current_io->state, pathname, mode);
+	return (void *)MOCK_HANDLE;
+}
+
+int __wrap_stat(const char *path, void *buf)
+{
+	LOG_ME;
+	return 0;
+}
+
+int __wrap_stat64(const char *path, void *buf)
+{
+	LOG_ME;
+	return 0;
+}
+
+char *__wrap_fgets(char *buf, int len, FILE *fp)
+{
+	LOG_ME;
+	if (current_io && current_io->fgets)
+		return current_io->fgets(current_io->state, buf, len, fp);
 	return NULL;
 }
 
+size_t __wrap_fread(void *ptr, size_t size, size_t len, FILE *fp)
+{
+	LOG_ME;
+	if (current_io && current_io->fread)
+		return current_io->fread(current_io->state, ptr, size, len, fp);
+	return 0;
+}
+
+int __wrap_setvbuf(FILE *fp, char *buf, int type, size_t size)
+{
+	LOG_ME;
+	return 0;
+}
+
+int __wrap_fclose(FILE *fp)
+{
+	LOG_ME;
+	if (current_io && current_io->fclose)
+		return current_io->fclose(current_io->state, fp);
+	return 0;
+}
+
+int __wrap_feof(FILE *fp)
+{
+	/* LOG_ME; */
+	return 0;
+}
+
+int __wrap_ferror(FILE *fp)
+{
+	/* LOG_ME; */
+	return 0;
+}
+void __wrap_clearerr(FILE *fp)
+{
+	/* LOG_ME; */
+	return;
+}
+
 int __wrap_rget_io_perms(void)
 {
 	LOG_ME;
@@ -277,6 +340,7 @@ int main(void)
 		cmocka_unit_test(nicrealtek_init_and_shutdown_test_success),
 		cmocka_unit_test(dediprog_init_and_shutdown_test_success),
 		cmocka_unit_test(ene_lpc_init_and_shutdown_test_success),
+		cmocka_unit_test(linux_mtd_init_and_shutdown_test_success),
 		cmocka_unit_test(linux_spi_init_and_shutdown_test_success),
 		cmocka_unit_test(realtek_mst_init_and_shutdown_test_success),
 	};

tests/tests.h

@@ -46,6 +46,7 @@ void mec1308_init_and_shutdown_test_success(void **state);
 void nicrealtek_init_and_shutdown_test_success(void **state);
 void dediprog_init_and_shutdown_test_success(void **state);
 void ene_lpc_init_and_shutdown_test_success(void **state);
+void linux_mtd_init_and_shutdown_test_success(void **state);
 void linux_spi_init_and_shutdown_test_success(void **state);
 void realtek_mst_init_and_shutdown_test_success(void **state);