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authorDmitry Torokhov <dmitry.torokhov@gmail.com>2009-12-01 21:54:35 -0800
committerDmitry Torokhov <dmitry.torokhov@gmail.com>2009-12-01 21:57:48 -0800
commit66d2a5952eab875f1286e04f738ef029afdaf013 (patch)
tree6d30e807108ef7d2a56ec43271c45acc357df699 /drivers/char
parent6ee88d713fb75ab191515f66edffa4e866386565 (diff)
Input: keyboard - fix lack of locking when traversing handler->h_list
Keyboard handler should not attempt to traverse handler->h_list on its own, without any locking, otherwise it races with registering and unregistering of input handles which leads to crashes. Introduce input_handler_for_each_handle() helper that allows safely iterate over all handles attached to a particular handler and switch keyboard handler to use it. Reported-by: Jim Paradis <jparadis@redhat.com> Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
Diffstat (limited to 'drivers/char')
-rw-r--r--drivers/char/keyboard.c202
1 files changed, 105 insertions, 97 deletions
diff --git a/drivers/char/keyboard.c b/drivers/char/keyboard.c
index ca090e57e161..ff8e9345f3c9 100644
--- a/drivers/char/keyboard.c
+++ b/drivers/char/keyboard.c
@@ -46,8 +46,6 @@
extern void ctrl_alt_del(void);
-#define to_handle_h(n) container_of(n, struct input_handle, h_node)
-
/*
* Exported functions/variables
*/
@@ -191,78 +189,85 @@ EXPORT_SYMBOL_GPL(unregister_keyboard_notifier);
* etc.). So this means that scancodes for the extra function keys won't
* be valid for the first event device, but will be for the second.
*/
+
+struct getset_keycode_data {
+ unsigned int scancode;
+ unsigned int keycode;
+ int error;
+};
+
+static int getkeycode_helper(struct input_handle *handle, void *data)
+{
+ struct getset_keycode_data *d = data;
+
+ d->error = input_get_keycode(handle->dev, d->scancode, &d->keycode);
+
+ return d->error == 0; /* stop as soon as we successfully get one */
+}
+
int getkeycode(unsigned int scancode)
{
- struct input_handle *handle;
- int keycode;
- int error = -ENODEV;
+ struct getset_keycode_data d = { scancode, 0, -ENODEV };
- list_for_each_entry(handle, &kbd_handler.h_list, h_node) {
- error = input_get_keycode(handle->dev, scancode, &keycode);
- if (!error)
- return keycode;
- }
+ input_handler_for_each_handle(&kbd_handler, &d, getkeycode_helper);
- return error;
+ return d.error ?: d.keycode;
+}
+
+static int setkeycode_helper(struct input_handle *handle, void *data)
+{
+ struct getset_keycode_data *d = data;
+
+ d->error = input_set_keycode(handle->dev, d->scancode, d->keycode);
+
+ return d->error == 0; /* stop as soon as we successfully set one */
}
int setkeycode(unsigned int scancode, unsigned int keycode)
{
- struct input_handle *handle;
- int error = -ENODEV;
+ struct getset_keycode_data d = { scancode, keycode, -ENODEV };
- list_for_each_entry(handle, &kbd_handler.h_list, h_node) {
- error = input_set_keycode(handle->dev, scancode, keycode);
- if (!error)
- break;
- }
+ input_handler_for_each_handle(&kbd_handler, &d, setkeycode_helper);
- return error;
+ return d.error;
}
/*
* Making beeps and bells.
*/
-static void kd_nosound(unsigned long ignored)
+
+static int kd_sound_helper(struct input_handle *handle, void *data)
{
- struct input_handle *handle;
+ unsigned int *hz = data;
+ struct input_dev *dev = handle->dev;
- list_for_each_entry(handle, &kbd_handler.h_list, h_node) {
- if (test_bit(EV_SND, handle->dev->evbit)) {
- if (test_bit(SND_TONE, handle->dev->sndbit))
- input_inject_event(handle, EV_SND, SND_TONE, 0);
- if (test_bit(SND_BELL, handle->dev->sndbit))
- input_inject_event(handle, EV_SND, SND_BELL, 0);
- }
+ if (test_bit(EV_SND, dev->evbit)) {
+ if (test_bit(SND_TONE, dev->sndbit))
+ input_inject_event(handle, EV_SND, SND_TONE, *hz);
+ if (test_bit(SND_BELL, handle->dev->sndbit))
+ input_inject_event(handle, EV_SND, SND_BELL, *hz ? 1 : 0);
}
+
+ return 0;
+}
+
+static void kd_nosound(unsigned long ignored)
+{
+ static unsigned int zero;
+
+ input_handler_for_each_handle(&kbd_handler, &zero, kd_sound_helper);
}
static DEFINE_TIMER(kd_mksound_timer, kd_nosound, 0, 0);
void kd_mksound(unsigned int hz, unsigned int ticks)
{
- struct list_head *node;
+ del_timer_sync(&kd_mksound_timer);
- del_timer(&kd_mksound_timer);
+ input_handler_for_each_handle(&kbd_handler, &hz, kd_sound_helper);
- if (hz) {
- list_for_each_prev(node, &kbd_handler.h_list) {
- struct input_handle *handle = to_handle_h(node);
- if (test_bit(EV_SND, handle->dev->evbit)) {
- if (test_bit(SND_TONE, handle->dev->sndbit)) {
- input_inject_event(handle, EV_SND, SND_TONE, hz);
- break;
- }
- if (test_bit(SND_BELL, handle->dev->sndbit)) {
- input_inject_event(handle, EV_SND, SND_BELL, 1);
- break;
- }
- }
- }
- if (ticks)
- mod_timer(&kd_mksound_timer, jiffies + ticks);
- } else
- kd_nosound(0);
+ if (hz && ticks)
+ mod_timer(&kd_mksound_timer, jiffies + ticks);
}
EXPORT_SYMBOL(kd_mksound);
@@ -270,27 +275,34 @@ EXPORT_SYMBOL(kd_mksound);
* Setting the keyboard rate.
*/
-int kbd_rate(struct kbd_repeat *rep)
+static int kbd_rate_helper(struct input_handle *handle, void *data)
{
- struct list_head *node;
- unsigned int d = 0;
- unsigned int p = 0;
-
- list_for_each(node, &kbd_handler.h_list) {
- struct input_handle *handle = to_handle_h(node);
- struct input_dev *dev = handle->dev;
-
- if (test_bit(EV_REP, dev->evbit)) {
- if (rep->delay > 0)
- input_inject_event(handle, EV_REP, REP_DELAY, rep->delay);
- if (rep->period > 0)
- input_inject_event(handle, EV_REP, REP_PERIOD, rep->period);
- d = dev->rep[REP_DELAY];
- p = dev->rep[REP_PERIOD];
- }
+ struct input_dev *dev = handle->dev;
+ struct kbd_repeat *rep = data;
+
+ if (test_bit(EV_REP, dev->evbit)) {
+
+ if (rep[0].delay > 0)
+ input_inject_event(handle,
+ EV_REP, REP_DELAY, rep[0].delay);
+ if (rep[0].period > 0)
+ input_inject_event(handle,
+ EV_REP, REP_PERIOD, rep[0].period);
+
+ rep[1].delay = dev->rep[REP_DELAY];
+ rep[1].period = dev->rep[REP_PERIOD];
}
- rep->delay = d;
- rep->period = p;
+
+ return 0;
+}
+
+int kbd_rate(struct kbd_repeat *rep)
+{
+ struct kbd_repeat data[2] = { *rep };
+
+ input_handler_for_each_handle(&kbd_handler, data, kbd_rate_helper);
+ *rep = data[1]; /* Copy currently used settings */
+
return 0;
}
@@ -998,36 +1010,36 @@ static inline unsigned char getleds(void)
return leds;
}
+static int kbd_update_leds_helper(struct input_handle *handle, void *data)
+{
+ unsigned char leds = *(unsigned char *)data;
+
+ if (test_bit(EV_LED, handle->dev->evbit)) {
+ input_inject_event(handle, EV_LED, LED_SCROLLL, !!(leds & 0x01));
+ input_inject_event(handle, EV_LED, LED_NUML, !!(leds & 0x02));
+ input_inject_event(handle, EV_LED, LED_CAPSL, !!(leds & 0x04));
+ input_inject_event(handle, EV_SYN, SYN_REPORT, 0);
+ }
+
+ return 0;
+}
+
/*
- * This routine is the bottom half of the keyboard interrupt
- * routine, and runs with all interrupts enabled. It does
- * console changing, led setting and copy_to_cooked, which can
- * take a reasonably long time.
- *
- * Aside from timing (which isn't really that important for
- * keyboard interrupts as they happen often), using the software
- * interrupt routines for this thing allows us to easily mask
- * this when we don't want any of the above to happen.
- * This allows for easy and efficient race-condition prevention
- * for kbd_start => input_inject_event(dev, EV_LED, ...) => ...
+ * This is the tasklet that updates LED state on all keyboards
+ * attached to the box. The reason we use tasklet is that we
+ * need to handle the scenario when keyboard handler is not
+ * registered yet but we already getting updates form VT to
+ * update led state.
*/
-
static void kbd_bh(unsigned long dummy)
{
- struct list_head *node;
unsigned char leds = getleds();
if (leds != ledstate) {
- list_for_each(node, &kbd_handler.h_list) {
- struct input_handle *handle = to_handle_h(node);
- input_inject_event(handle, EV_LED, LED_SCROLLL, !!(leds & 0x01));
- input_inject_event(handle, EV_LED, LED_NUML, !!(leds & 0x02));
- input_inject_event(handle, EV_LED, LED_CAPSL, !!(leds & 0x04));
- input_inject_event(handle, EV_SYN, SYN_REPORT, 0);
- }
+ input_handler_for_each_handle(&kbd_handler, &leds,
+ kbd_update_leds_helper);
+ ledstate = leds;
}
-
- ledstate = leds;
}
DECLARE_TASKLET_DISABLED(keyboard_tasklet, kbd_bh, 0);
@@ -1370,15 +1382,11 @@ static void kbd_disconnect(struct input_handle *handle)
*/
static void kbd_start(struct input_handle *handle)
{
- unsigned char leds = ledstate;
-
tasklet_disable(&keyboard_tasklet);
- if (leds != 0xff) {
- input_inject_event(handle, EV_LED, LED_SCROLLL, !!(leds & 0x01));
- input_inject_event(handle, EV_LED, LED_NUML, !!(leds & 0x02));
- input_inject_event(handle, EV_LED, LED_CAPSL, !!(leds & 0x04));
- input_inject_event(handle, EV_SYN, SYN_REPORT, 0);
- }
+
+ if (ledstate != 0xff)
+ kbd_update_leds_helper(handle, &ledstate);
+
tasklet_enable(&keyboard_tasklet);
}