Input: psmouse - make sure we do not use stale methods

Several protocol initialization routines can fail after they set up
psmouse methods, such as reconnect and disconnect. This may lead to
these stale methods used with different protocol that they were
intended to be used for and may cause unpredictavle behavior and/or
crashes.

Make sure we start with a clean slate before executing each and every
protocol detection and/or initialization routine.
Reported-by: NPaul Fox <pgf@laptop.org>
Acked-by: NTai-hwa Liang <avatar@sentelic.com>
Acked-by: NPaul Fox <pgf@laptop.org>
Signed-off-by: NDmitry Torokhov <dtor@mail.ru>

drivers/input/mouse/psmouse-base.c

@@ -418,6 +418,49 @@ int psmouse_reset(struct psmouse *psmouse)
 	return 0;
 }
 
+/*
+ * Here we set the mouse resolution.
+ */
+
+void psmouse_set_resolution(struct psmouse *psmouse, unsigned int resolution)
+{
+	static const unsigned char params[] = { 0, 1, 2, 2, 3 };
+	unsigned char p;
+
+	if (resolution == 0 || resolution > 200)
+		resolution = 200;
+
+	p = params[resolution / 50];
+	ps2_command(&psmouse->ps2dev, &p, PSMOUSE_CMD_SETRES);
+	psmouse->resolution = 25 << p;
+}
+
+/*
+ * Here we set the mouse report rate.
+ */
+
+static void psmouse_set_rate(struct psmouse *psmouse, unsigned int rate)
+{
+	static const unsigned char rates[] = { 200, 100, 80, 60, 40, 20, 10, 0 };
+	unsigned char r;
+	int i = 0;
+
+	while (rates[i] > rate) i++;
+	r = rates[i];
+	ps2_command(&psmouse->ps2dev, &r, PSMOUSE_CMD_SETRATE);
+	psmouse->rate = r;
+}
+
+/*
+ * psmouse_poll() - default poll handler. Everyone except for ALPS uses it.
+ */
+
+static int psmouse_poll(struct psmouse *psmouse)
+{
+	return ps2_command(&psmouse->ps2dev, psmouse->packet,
+			   PSMOUSE_CMD_POLL | (psmouse->pktsize << 8));
+}
+
 
 /*
  * Genius NetMouse magic init.
@@ -602,6 +645,56 @@ static int cortron_detect(struct psmouse *psmouse, bool set_properties)
 	return 0;
 }
 
+/*
+ * Apply default settings to the psmouse structure. Most of them will
+ * be overridden by individual protocol initialization routines.
+ */
+
+static void psmouse_apply_defaults(struct psmouse *psmouse)
+{
+	struct input_dev *input_dev = psmouse->dev;
+
+	memset(input_dev->evbit, 0, sizeof(input_dev->evbit));
+	memset(input_dev->keybit, 0, sizeof(input_dev->keybit));
+	memset(input_dev->relbit, 0, sizeof(input_dev->relbit));
+	memset(input_dev->absbit, 0, sizeof(input_dev->absbit));
+	memset(input_dev->mscbit, 0, sizeof(input_dev->mscbit));
+
+	__set_bit(EV_KEY, input_dev->evbit);
+	__set_bit(EV_REL, input_dev->evbit);
+
+	__set_bit(BTN_LEFT, input_dev->keybit);
+	__set_bit(BTN_RIGHT, input_dev->keybit);
+
+	__set_bit(REL_X, input_dev->relbit);
+	__set_bit(REL_Y, input_dev->relbit);
+
+	psmouse->set_rate = psmouse_set_rate;
+	psmouse->set_resolution = psmouse_set_resolution;
+	psmouse->poll = psmouse_poll;
+	psmouse->protocol_handler = psmouse_process_byte;
+	psmouse->pktsize = 3;
+	psmouse->reconnect = NULL;
+	psmouse->disconnect = NULL;
+	psmouse->cleanup = NULL;
+	psmouse->pt_activate = NULL;
+	psmouse->pt_deactivate = NULL;
+}
+
+/*
+ * Apply default settings to the psmouse structure and call specified
+ * protocol detection or initialization routine.
+ */
+static int psmouse_do_detect(int (*detect)(struct psmouse *psmouse,
+					   bool set_properties),
+			     struct psmouse *psmouse, bool set_properties)
+{
+	if (set_properties)
+		psmouse_apply_defaults(psmouse);
+
+	return detect(psmouse, set_properties);
+}
+
 /*
  * psmouse_extensions() probes for any extensions to the basic PS/2 protocol
  * the mouse may have.
@@ -616,7 +709,7 @@ static int psmouse_extensions(struct psmouse *psmouse,
  * We always check for lifebook because it does not disturb mouse
  * (it only checks DMI information).
  */
-	if (lifebook_detect(psmouse, set_properties) == 0) {
+	if (psmouse_do_detect(lifebook_detect, psmouse, set_properties) == 0) {
 		if (max_proto > PSMOUSE_IMEX) {
 			if (!set_properties || lifebook_init(psmouse) == 0)
 				return PSMOUSE_LIFEBOOK;
@@ -628,15 +721,18 @@ static int psmouse_extensions(struct psmouse *psmouse,
  * upsets the thinkingmouse).
  */
 
-	if (max_proto > PSMOUSE_IMEX && thinking_detect(psmouse, set_properties) == 0)
+	if (max_proto > PSMOUSE_IMEX &&
+	    psmouse_do_detect(thinking_detect, psmouse, set_properties) == 0) {
 		return PSMOUSE_THINKPS;
+	}
 
 /*
  * Try Synaptics TouchPad. Note that probing is done even if Synaptics protocol
  * support is disabled in config - we need to know if it is synaptics so we
  * can reset it properly after probing for intellimouse.
  */
-	if (max_proto > PSMOUSE_PS2 && synaptics_detect(psmouse, set_properties) == 0) {
+	if (max_proto > PSMOUSE_PS2 &&
+	    psmouse_do_detect(synaptics_detect, psmouse, set_properties) == 0) {
 		synaptics_hardware = true;
 
 		if (max_proto > PSMOUSE_IMEX) {
@@ -667,7 +763,8 @@ static int psmouse_extensions(struct psmouse *psmouse,
  */
 	if (max_proto > PSMOUSE_IMEX) {
 		ps2_command(&psmouse->ps2dev, NULL, PSMOUSE_CMD_RESET_DIS);
-		if (alps_detect(psmouse, set_properties) == 0) {
+		if (psmouse_do_detect(alps_detect,
+				      psmouse, set_properties) == 0) {
 			if (!set_properties || alps_init(psmouse) == 0)
 				return PSMOUSE_ALPS;
 /*
@@ -681,7 +778,7 @@ static int psmouse_extensions(struct psmouse *psmouse,
  * Try OLPC HGPK touchpad.
  */
 	if (max_proto > PSMOUSE_IMEX &&
-			hgpk_detect(psmouse, set_properties) == 0) {
+	    psmouse_do_detect(hgpk_detect, psmouse, set_properties) == 0) {
 		if (!set_properties || hgpk_init(psmouse) == 0)
 			return PSMOUSE_HGPK;
 /*
@@ -694,7 +791,7 @@ static int psmouse_extensions(struct psmouse *psmouse,
  * Try Elantech touchpad.
  */
 	if (max_proto > PSMOUSE_IMEX &&
-			elantech_detect(psmouse, set_properties) == 0) {
+	    psmouse_do_detect(elantech_detect, psmouse, set_properties) == 0) {
 		if (!set_properties || elantech_init(psmouse) == 0)
 			return PSMOUSE_ELANTECH;
 /*
@@ -703,18 +800,21 @@ static int psmouse_extensions(struct psmouse *psmouse,
 		max_proto = PSMOUSE_IMEX;
 	}
 
-
 	if (max_proto > PSMOUSE_IMEX) {
-		if (genius_detect(psmouse, set_properties) == 0)
+		if (psmouse_do_detect(genius_detect,
+				      psmouse, set_properties) == 0)
 			return PSMOUSE_GENPS;
 
-		if (ps2pp_init(psmouse, set_properties) == 0)
+		if (psmouse_do_detect(ps2pp_init,
+				      psmouse, set_properties) == 0)
 			return PSMOUSE_PS2PP;
 
-		if (trackpoint_detect(psmouse, set_properties) == 0)
+		if (psmouse_do_detect(trackpoint_detect,
+				      psmouse, set_properties) == 0)
 			return PSMOUSE_TRACKPOINT;
 
-		if (touchkit_ps2_detect(psmouse, set_properties) == 0)
+		if (psmouse_do_detect(touchkit_ps2_detect,
+				      psmouse, set_properties) == 0)
 			return PSMOUSE_TOUCHKIT_PS2;
 	}
 
@@ -723,7 +823,8 @@ static int psmouse_extensions(struct psmouse *psmouse,
  * Trackpoint devices (causing TP_READ_ID command to time out).
  */
 	if (max_proto > PSMOUSE_IMEX) {
-		if (fsp_detect(psmouse, set_properties) == 0) {
+		if (psmouse_do_detect(fsp_detect,
+				      psmouse, set_properties) == 0) {
 			if (!set_properties || fsp_init(psmouse) == 0)
 				return PSMOUSE_FSP;
 /*
@@ -741,17 +842,23 @@ static int psmouse_extensions(struct psmouse *psmouse,
 	ps2_command(&psmouse->ps2dev, NULL, PSMOUSE_CMD_RESET_DIS);
 	psmouse_reset(psmouse);
 
-	if (max_proto >= PSMOUSE_IMEX && im_explorer_detect(psmouse, set_properties) == 0)
+	if (max_proto >= PSMOUSE_IMEX &&
+	    psmouse_do_detect(im_explorer_detect,
+			      psmouse, set_properties) == 0) {
 		return PSMOUSE_IMEX;
+	}
 
-	if (max_proto >= PSMOUSE_IMPS && intellimouse_detect(psmouse, set_properties) == 0)
+	if (max_proto >= PSMOUSE_IMPS &&
+	    psmouse_do_detect(intellimouse_detect,
+			      psmouse, set_properties) == 0) {
 		return PSMOUSE_IMPS;
+	}
 
 /*
  * Okay, all failed, we have a standard mouse here. The number of the buttons
  * is still a question, though. We assume 3.
  */
-	ps2bare_detect(psmouse, set_properties);
+	psmouse_do_detect(ps2bare_detect, psmouse, set_properties);
 
 	if (synaptics_hardware) {
 /*
@@ -964,39 +1071,6 @@ static int psmouse_probe(struct psmouse *psmouse)
 	return 0;
 }
 
-/*
- * Here we set the mouse resolution.
- */
-
-void psmouse_set_resolution(struct psmouse *psmouse, unsigned int resolution)
-{
-	static const unsigned char params[] = { 0, 1, 2, 2, 3 };
-	unsigned char p;
-
-	if (resolution == 0 || resolution > 200)
-		resolution = 200;
-
-	p = params[resolution / 50];
-	ps2_command(&psmouse->ps2dev, &p, PSMOUSE_CMD_SETRES);
-	psmouse->resolution = 25 << p;
-}
-
-/*
- * Here we set the mouse report rate.
- */
-
-static void psmouse_set_rate(struct psmouse *psmouse, unsigned int rate)
-{
-	static const unsigned char rates[] = { 200, 100, 80, 60, 40, 20, 10, 0 };
-	unsigned char r;
-	int i = 0;
-
-	while (rates[i] > rate) i++;
-	r = rates[i];
-	ps2_command(&psmouse->ps2dev, &r, PSMOUSE_CMD_SETRATE);
-	psmouse->rate = r;
-}
-
 /*
  * psmouse_initialize() initializes the mouse to a sane state.
  */
@@ -1042,16 +1116,6 @@ static void psmouse_deactivate(struct psmouse *psmouse)
 	psmouse_set_state(psmouse, PSMOUSE_CMD_MODE);
 }
 
-/*
- * psmouse_poll() - default poll handler. Everyone except for ALPS uses it.
- */
-
-static int psmouse_poll(struct psmouse *psmouse)
-{
-	return ps2_command(&psmouse->ps2dev, psmouse->packet,
-			   PSMOUSE_CMD_POLL | (psmouse->pktsize << 8));
-}
-
 
 /*
  * psmouse_resync() attempts to re-validate current protocol.
@@ -1252,18 +1316,9 @@ static int psmouse_switch_protocol(struct psmouse *psmouse,
 
 	input_dev->dev.parent = &psmouse->ps2dev.serio->dev;
 
-	input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_REL);
-	input_dev->keybit[BIT_WORD(BTN_MOUSE)] =
-				BIT_MASK(BTN_LEFT) | BIT_MASK(BTN_RIGHT);
-	input_dev->relbit[0] = BIT_MASK(REL_X) | BIT_MASK(REL_Y);
-
-	psmouse->set_rate = psmouse_set_rate;
-	psmouse->set_resolution = psmouse_set_resolution;
-	psmouse->poll = psmouse_poll;
-	psmouse->protocol_handler = psmouse_process_byte;
-	psmouse->pktsize = 3;
-
 	if (proto && (proto->detect || proto->init)) {
+		psmouse_apply_defaults(psmouse);
+
 		if (proto->detect && proto->detect(psmouse, true) < 0)
 			return -1;