Input: pmouse - introduce proper locking so state-changing
operations do not iterfere with each other.
Also make sure that serio core takes serio->drv_sem
not only for connect/disconnect but for reconnect
too.
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
diff --git a/drivers/input/mouse/psmouse-base.c b/drivers/input/mouse/psmouse-base.c
index 0ecf129..259e6b7 100644
--- a/drivers/input/mouse/psmouse-base.c
+++ b/drivers/input/mouse/psmouse-base.c
@@ -68,6 +68,15 @@
__obsolete_setup("psmouse_resetafter=");
__obsolete_setup("psmouse_rate=");
+/*
+ * psmouse_sem protects all operations changing state of mouse
+ * (connecting, disconnecting, changing rate or resolution via
+ * sysfs). We could use a per-device semaphore but since there
+ * rarely more than one PS/2 mouse connected and since semaphore
+ * is taken in "slow" paths it is not worth it.
+ */
+static DECLARE_MUTEX(psmouse_sem);
+
static char *psmouse_protocols[] = { "None", "PS/2", "PS2++", "ThinkPS/2", "GenPS/2", "ImPS/2", "ImExPS/2", "SynPS/2", "AlpsPS/2", "LBPS/2" };
/*
@@ -667,30 +676,40 @@
static void psmouse_disconnect(struct serio *serio)
{
- struct psmouse *psmouse, *parent;
+ struct psmouse *psmouse, *parent = NULL;
+
+ psmouse = serio_get_drvdata(serio);
device_remove_file(&serio->dev, &psmouse_attr_rate);
device_remove_file(&serio->dev, &psmouse_attr_resolution);
device_remove_file(&serio->dev, &psmouse_attr_resetafter);
- psmouse = serio_get_drvdata(serio);
+ down(&psmouse_sem);
+
psmouse_set_state(psmouse, PSMOUSE_CMD_MODE);
if (serio->parent && serio->id.type == SERIO_PS_PSTHRU) {
parent = serio_get_drvdata(serio->parent);
- if (parent->pt_deactivate)
- parent->pt_deactivate(parent);
+ psmouse_deactivate(parent);
}
if (psmouse->disconnect)
psmouse->disconnect(psmouse);
+ if (parent && parent->pt_deactivate)
+ parent->pt_deactivate(parent);
+
psmouse_set_state(psmouse, PSMOUSE_IGNORE);
input_unregister_device(&psmouse->dev);
serio_close(serio);
serio_set_drvdata(serio, NULL);
kfree(psmouse);
+
+ if (parent)
+ psmouse_activate(parent);
+
+ up(&psmouse_sem);
}
/*
@@ -702,6 +721,8 @@
struct psmouse *psmouse, *parent = NULL;
int retval;
+ down(&psmouse_sem);
+
/*
* If this is a pass-through port deactivate parent so the device
* connected to this port can be successfully identified
@@ -711,13 +732,11 @@
psmouse_deactivate(parent);
}
- if (!(psmouse = kmalloc(sizeof(struct psmouse), GFP_KERNEL))) {
+ if (!(psmouse = kcalloc(1, sizeof(struct psmouse), GFP_KERNEL))) {
retval = -ENOMEM;
goto out;
}
- memset(psmouse, 0, sizeof(struct psmouse));
-
ps2_init(&psmouse->ps2dev, serio);
sprintf(psmouse->phys, "%s/input0", serio->phys);
psmouse->dev.evbit[0] = BIT(EV_KEY) | BIT(EV_REL);
@@ -785,10 +804,11 @@
retval = 0;
out:
- /* If this is a pass-through port the parent awaits to be activated */
+ /* If this is a pass-through port the parent needs to be re-activated */
if (parent)
psmouse_activate(parent);
+ up(&psmouse_sem);
return retval;
}
@@ -805,6 +825,8 @@
return -1;
}
+ down(&psmouse_sem);
+
if (serio->parent && serio->id.type == SERIO_PS_PSTHRU) {
parent = serio_get_drvdata(serio->parent);
psmouse_deactivate(parent);
@@ -837,6 +859,7 @@
if (parent)
psmouse_activate(parent);
+ up(&psmouse_sem);
return rc;
}
@@ -907,7 +930,16 @@
if (serio->drv != &psmouse_drv) {
retval = -ENODEV;
- goto out;
+ goto out_unpin;
+ }
+
+ retval = down_interruptible(&psmouse_sem);
+ if (retval)
+ goto out_unpin;
+
+ if (psmouse->state == PSMOUSE_IGNORE) {
+ retval = -ENODEV;
+ goto out_up;
}
if (serio->parent && serio->id.type == SERIO_PS_PSTHRU) {
@@ -922,7 +954,9 @@
if (parent)
psmouse_activate(parent);
-out:
+ out_up:
+ up(&psmouse_sem);
+ out_unpin:
serio_unpin_driver(serio);
return retval;
}