fpsensor: Deinit the sensor before clearing the context

The opaque context contains sensor state that we can't nuke from
underneath the sensor library. Calling fp_sensor_deinit will release
this context and allow us to safely clear the context.

BRANCH=none
BUG=b:124773209
TEST="fpenroll" followed by "fpclear" in the FP console
TEST=On nocturne, in the UI, enroll finger, log out, and log in
     => then lock and unlock with finger
TEST=make buildall -j

Change-Id: I3e25bdf7eaaf99f3801547e11a6c524f924f4726
Signed-off-by: Tom Hughes <tomhughes@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/ec/+/1647294
Reviewed-by: Nicolas Norvez <norvez@chromium.org>
Commit-Queue: Yicheng Li <yichengli@chromium.org>
Tested-by: Yicheng Li <yichengli@chromium.org>

9 files changed, 65 insertions, 12 deletions

diff --git a/common/fpsensor/fpsensor.c b/common/fpsensor/fpsensor.c
index d0bc54faba..11060baf6c 100644
--- a/common/fpsensor/fpsensor.c
+++ b/common/fpsensor/fpsensor.c
@@ -243,8 +243,7 @@ void fp_task(void)
 			if (mode & FP_MODE_ANY_WAIT_IRQ) {
 				gpio_enable_interrupt(GPIO_FPS_INT);
 			} else if (mode & FP_MODE_RESET_SENSOR) {
-				fp_clear_context();
-				fp_sensor_init();
+				fp_reset_and_clear_context();
 				sensor_mode &= ~FP_MODE_RESET_SENSOR;
 			} else {
 				fp_sensor_low_power();
@@ -602,7 +601,8 @@ static enum ec_error_list fp_console_action(uint32_t mode)
 	uint32_t mode_output = 0;
 	int rc = 0;
 
-	CPRINTS("Waiting for finger ...");
+	if (!(sensor_mode & FP_MODE_RESET_SENSOR))
+		CPRINTS("Waiting for finger ...");
 
 	rc = fp_set_sensor_mode(mode, &mode_output);
 
@@ -709,8 +709,18 @@ DECLARE_CONSOLE_COMMAND(fpmatch, command_fpmatch, NULL,
 
 int command_fpclear(int argc, char **argv)
 {
-	fp_clear_context();
-	return EC_SUCCESS;
+	/*
+	 * We intentionally run this on the fp_task so that we use the
+	 * same code path as host commands.
+	 */
+	enum ec_error_list rc = fp_console_action(FP_MODE_RESET_SENSOR);
+
+	if (rc < 0)
+		CPRINTS("Failed to clear fingerprint context: %d", rc);
+
+	atomic_read_clear(&fp_events);
+
+	return rc;
 }
 DECLARE_CONSOLE_COMMAND(fpclear, command_fpclear, NULL,
 			"Clear fingerprint sensor context");
diff --git a/common/fpsensor/fpsensor_state.c b/common/fpsensor/fpsensor_state.c
index 7474634487..bfbf0c6cb5 100644
--- a/common/fpsensor/fpsensor_state.c
+++ b/common/fpsensor/fpsensor_state.c
@@ -55,7 +55,12 @@ void fp_clear_finger_context(int idx)
 	always_memset(fp_template[idx], 0, sizeof(fp_template[0]));
 }
 
-void fp_clear_context(void)
+/**
+ * @warning |fp_buffer| contains data used by the matching algorithm that must
+ * be released by calling fp_sensor_deinit() first. Call
+ * fp_reset_and_clear_context instead of calling this directly.
+ */
+static void _fp_clear_context(void)
 {
 	int idx;
 
@@ -66,7 +71,15 @@ void fp_clear_context(void)
 	always_memset(user_id, 0, sizeof(user_id));
 	for (idx = 0; idx < FP_MAX_FINGER_COUNT; idx++)
 		fp_clear_finger_context(idx);
-	/* TODO maybe shutdown and re-init the private libraries ? */
+}
+
+void fp_reset_and_clear_context(void)
+{
+	if (fp_sensor_deinit() != EC_SUCCESS)
+		CPRINTS("Failed to deinit sensor");
+	_fp_clear_context();
+	if (fp_sensor_init() != EC_SUCCESS)
+		CPRINTS("Failed to init sensor");
 }
 
 int fp_get_next_event(uint8_t *out)
@@ -187,7 +200,7 @@ static int fp_command_context(struct host_cmd_handler_args *args)
 {
 	const struct ec_params_fp_context *params = args->params;
 
-	fp_clear_context();
+	fp_reset_and_clear_context();
 
 	memcpy(user_id, params->userid, sizeof(user_id));
 
diff --git a/common/mock/README.md b/common/mock/README.md
index e1962651a6..0044856639 100644
--- a/common/mock/README.md
+++ b/common/mock/README.md
@@ -43,7 +43,7 @@ Example `.mocklist`:
 
  #define CONFIG_TEST_MOCK_LIST \
 	MOCK(ROLLBACK)         \
-	MOCK(FP_SENSOR)
+	MOCK(FPSENSOR)
 ```
 
 If you need additional mock control functionality, you may need to include
diff --git a/common/mock/build.mk b/common/mock/build.mk
index 037718d3bb..e89c658968 100644
--- a/common/mock/build.mk
+++ b/common/mock/build.mk
@@ -4,4 +4,5 @@
 
 # See common/mock/README.md for more information.
 
+mock-$(HAS_MOCK_FPSENSOR) += fpsensor_mock.o
 mock-$(HAS_MOCK_ROLLBACK) += rollback_mock.o
diff --git a/common/mock/fpsensor_mock.c b/common/mock/fpsensor_mock.c
new file mode 100644
index 0000000000..7ace5c2f43
--- /dev/null
+++ b/common/mock/fpsensor_mock.c
@@ -0,0 +1,17 @@
+/* Copyright 2019 The Chromium OS Authors. All rights reserved.
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#include "common.h"
+
+/* No-op mocks */
+int fp_sensor_init(void)
+{
+	return EC_SUCCESS;
+}
+
+int fp_sensor_deinit(void)
+{
+	return EC_SUCCESS;
+}
diff --git a/fuzz/host_command_fuzz.mocklist b/fuzz/host_command_fuzz.mocklist
index d84275532e..97b5e74c73 100644
--- a/fuzz/host_command_fuzz.mocklist
+++ b/fuzz/host_command_fuzz.mocklist
@@ -4,4 +4,5 @@
  */
 
  #define CONFIG_TEST_MOCK_LIST \
+        MOCK(FPSENSOR) \
         MOCK(ROLLBACK)
diff --git a/include/fpsensor.h b/include/fpsensor.h
index 9a3d2c4e21..ce8abaf870 100644
--- a/include/fpsensor.h
+++ b/include/fpsensor.h
@@ -28,6 +28,9 @@
 /* Initialize the connected sensor hardware and put it in a low power mode. */
 int fp_sensor_init(void);
 
+/* De-initialize the sensor hardware. */
+int fp_sensor_deinit(void);
+
 /*
  * Fill the 'ec_response_fp_info' buffer with the sensor information
  * as required by the EC_CMD_FP_INFO host command.
diff --git a/include/fpsensor_state.h b/include/fpsensor_state.h
index 8b5ab6ef0c..76b88d79b8 100644
--- a/include/fpsensor_state.h
+++ b/include/fpsensor_state.h
@@ -78,10 +78,11 @@ void fp_task_simulate(void);
  */
 void fp_clear_finger_context(int idx);
 
-/*
- * Clear all fingerprint templates associated with the current user id.
+/**
+ * Clear all fingerprint templates associated with the current user id and
+ * reset the sensor.
  */
-void fp_clear_context(void);
+void fp_reset_and_clear_context(void);
 
 /*
  * Get the next FP event.
diff --git a/test/fpsensor.mocklist b/test/fpsensor.mocklist
new file mode 100644
index 0000000000..9bed932526
--- /dev/null
+++ b/test/fpsensor.mocklist
@@ -0,0 +1,7 @@
+/* Copyright 2019 The Chromium OS Authors. All rights reserved.
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+ #define CONFIG_TEST_MOCK_LIST \
+        MOCK(FPSENSOR)