Commit 3516fa16 authored by Dmitry Torokhov's avatar Dmitry Torokhov
Browse files

Input: avoid calling input_set_abs_val() in the event handling core 



input_abs_set_val() can nominally call input_alloc_absinfo() which may
allocate memory with GFP_KERNEL flag. This does not happen when
input_abs_set_val() is called by the input core to set current MT slot when
handling a new input event, but it trips certain static analyzers.

Rearrange the code to access the relevant structures directly.

Reported-by: default avatarTeng Qi <starmiku1207184332@gmail.com>
Reviewed-by: default avatarPeter Hutterer <peter.hutterer@who-t.net>
Link: https://lore.kernel.org/r/ZFBg379uuHjf+YEM@google.com


Signed-off-by: default avatarDmitry Torokhov <dmitry.torokhov@gmail.com>
parent e0f41f83

drivers/input/input.c

+4 −2
Original line number Diff line number Diff line
@@ -190,6 +190,7 @@ static int input_handle_abs_event(struct input_dev *dev, 
				  unsigned int code, int *pval)

{

	struct input_mt *mt = dev->mt;

	bool is_new_slot = false;

	bool is_mt_event;

	int *pold;
@@ -210,6 +211,7 @@ static int input_handle_abs_event(struct input_dev *dev, 
		pold = &dev->absinfo[code].value;

	} else if (mt) {

		pold = &mt->slots[mt->slot].abs[code - ABS_MT_FIRST];

		is_new_slot = mt->slot != dev->absinfo[ABS_MT_SLOT].value;

	} else {

		/*

		 * Bypass filtering for multi-touch events when
@@ -228,8 +230,8 @@ static int input_handle_abs_event(struct input_dev *dev, 
	}



	/* Flush pending "slot" event */

	if (is_mt_event && mt && mt->slot != input_abs_get_val(dev, ABS_MT_SLOT)) {

		input_abs_set_val(dev, ABS_MT_SLOT, mt->slot);

	if (is_new_slot) {

		dev->absinfo[ABS_MT_SLOT].value = mt->slot;

		return INPUT_PASS_TO_HANDLERS | INPUT_SLOT;

	}