[PATCH v2 06/12] fuzzing_engine: Add fuzzing engine uclass

Andrew Scull
2022-04-14T14:01:06Z

This new class of device will provide fuzzing inputs from a fuzzing
engine.

Signed-off-by: Andrew Scull <ascull@google.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
---
drivers/Kconfig | 2 ++
drivers/Makefile | 1 +
drivers/fuzz/Kconfig | 9 +++++
drivers/fuzz/Makefile | 7 ++++
drivers/fuzz/fuzzing_engine-uclass.c | 28 +++++++++++++++
include/dm/uclass-id.h | 1 +
include/fuzzing_engine.h | 51 ++++++++++++++++++++++++++++
7 files changed, 99 insertions(+)
create mode 100644 drivers/fuzz/Kconfig
create mode 100644 drivers/fuzz/Makefile
create mode 100644 drivers/fuzz/fuzzing_engine-uclass.c
create mode 100644 include/fuzzing_engine.h

diff --git a/drivers/Kconfig b/drivers/Kconfig
index b26ca8cf70..8b6fead351 100644
--- a/drivers/Kconfig
+++ b/drivers/Kconfig
@@ -40,6 +40,8 @@ source "drivers/fastboot/Kconfig"

source "drivers/firmware/Kconfig"

+source "drivers/fuzz/Kconfig"
+
source "drivers/fpga/Kconfig"

source "drivers/gpio/Kconfig"
diff --git a/drivers/Makefile b/drivers/Makefile
index 4e7cf28440..b66d72d361 100644
--- a/drivers/Makefile
+++ b/drivers/Makefile
@@ -113,6 +113,7 @@ obj-$(CONFIG_W1) += w1/
obj-$(CONFIG_W1_EEPROM) += w1-eeprom/

obj-$(CONFIG_MACH_PIC32) += ddr/microchip/
+obj-$(CONFIG_FUZZ) += fuzz/
obj-$(CONFIG_DM_HWSPINLOCK) += hwspinlock/
obj-$(CONFIG_DM_RNG) += rng/
endif
diff --git a/drivers/fuzz/Kconfig b/drivers/fuzz/Kconfig
new file mode 100644
index 0000000000..a03120f63a
--- /dev/null
+++ b/drivers/fuzz/Kconfig
@@ -0,0 +1,9 @@
+config DM_FUZZING_ENGINE
+ bool "Driver support for fuzzing engine devices"
+ depends on DM
+ help
+ Enable driver model for fuzzing engine devices. This interface is
+ used to get successive inputs from a fuzzing engine that aims to
+ explore different code paths in a fuzz test. The fuzzing engine may
+ be instrumenting the execution in order to more effectively generate
+ inputs that explore different code paths.
diff --git a/drivers/fuzz/Makefile b/drivers/fuzz/Makefile
new file mode 100644
index 0000000000..acd894999c
--- /dev/null
+++ b/drivers/fuzz/Makefile
@@ -0,0 +1,7 @@
+# SPDX-License-Identifier: GPL-2.0+
+#
+# Copyright (c) 2022 Google, Inc.
+# Written by Andrew Scull <ascull@google.com>
+#
+
+obj-$(CONFIG_DM_FUZZING_ENGINE) += fuzzing_engine-uclass.o
diff --git a/drivers/fuzz/fuzzing_engine-uclass.c b/drivers/fuzz/fuzzing_engine-uclass.c
new file mode 100644
index 0000000000..b16f1c4cfb
--- /dev/null
+++ b/drivers/fuzz/fuzzing_engine-uclass.c
@@ -0,0 +1,28 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+/*
+ * Copyright (c) 2022 Google, Inc.
+ * Written by Andrew Scull <ascull@google.com>
+ */
+
+#define LOG_CATEGORY UCLASS_FUZZING_ENGINE
+
+#include <common.h>
+#include <dm.h>
+#include <fuzzing_engine.h>
+
+int dm_fuzzing_engine_get_input(struct udevice *dev,
+ const uint8_t **data,
+ size_t *size)
+{
+ const struct dm_fuzzing_engine_ops *ops = device_get_ops(dev);
+
+ if (!ops->get_input)
+ return -ENOSYS;
+
+ return ops->get_input(dev, data, size);
+}
+
+UCLASS_DRIVER(fuzzing_engine) = {
+ .name = "fuzzing_engine",
+ .id = UCLASS_FUZZING_ENGINE,
+};
diff --git a/include/dm/uclass-id.h b/include/dm/uclass-id.h
index 0e26e1d138..b9411f1d59 100644
--- a/include/dm/uclass-id.h
+++ b/include/dm/uclass-id.h
@@ -53,6 +53,7 @@ enum uclass_id {
UCLASS_ETH, /* Ethernet device */
UCLASS_ETH_PHY, /* Ethernet PHY device */
UCLASS_FIRMWARE, /* Firmware */
+ UCLASS_FUZZING_ENGINE, /* Fuzzing engine */
UCLASS_FS_FIRMWARE_LOADER, /* Generic loader */
UCLASS_GPIO, /* Bank of general-purpose I/O pins */
UCLASS_HASH, /* Hash device */
diff --git a/include/fuzzing_engine.h b/include/fuzzing_engine.h
new file mode 100644
index 0000000000..357346e93d
--- /dev/null
+++ b/include/fuzzing_engine.h
@@ -0,0 +1,51 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+/*
+ * Copyright (c) 2022 Google, Inc.
+ * Written by Andrew Scull <ascull@google.com>
+ */
+
+#ifndef __FUZZING_ENGINE_H
+#define __FUZZING_ENGINE_H
+
+struct udevice;
+
+/**
+ * dm_fuzzing_engine_get_input() - get an input from the fuzzing engine device
+ *
+ * The function will return a pointer to the input data and the size of the
+ * data pointed to. The pointer will remain valid until the next invocation of
+ * this function.
+ *
+ * @dev: fuzzing engine device
+ * @data: output pointer to input data
+ * @size output size of input data
+ * Return: 0 if OK, -ve on error
+ */
+int dm_fuzzing_engine_get_input(struct udevice *dev,
+ const uint8_t **data,
+ size_t *size);
+
+/**
+ * struct dm_fuzzing_engine_ops - operations for the fuzzing engine uclass
+ *
+ * This contains the functions implemented by a fuzzing engine device.
+ */
+struct dm_fuzzing_engine_ops {
+ /**
+ * @get_input() - get an input
+ *
+ * The function will return a pointer to the input data and the size of
+ * the data pointed to. The pointer will remain valid until the next
+ * invocation of this function.
+ *
+ * @get_input.dev: fuzzing engine device
+ * @get_input.data: output pointer to input data
+ * @get_input.size output size of input data
+ * @get_input.Return: 0 if OK, -ve on error
+ */
+ int (*get_input)(struct udevice *dev,
+ const uint8_t **data,
+ size_t *size);
+};
+
+#endif /* __FUZZING_ENGINE_H */
--
2.35.1.1178.g4f1659d476-goog