linux-kernel - [PATCH 4.20 161/171] media: Revert "media: rc: some events are dropped by userspace"

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Message-Id: <20190312170401.277059083@linuxfoundation.org>
Date:   Tue, 12 Mar 2019 10:09:01 -0700
From:   Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To:     linux-kernel@...r.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        stable@...r.kernel.org, Christian Holpert <christian@...pert.de>,
        Sean Young <sean@...s.org>,
        Mauro Carvalho Chehab <mchehab+samsung@...nel.org>
Subject: [PATCH 4.20 161/171] media: Revert "media: rc: some events are dropped by userspace"

4.20-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Sean Young <sean@...s.org>

commit 05f0edadcc5fccdfc0676825b3e70e75dc0a8a84 upstream.

When an rc device is created, we do not know what key codes it will
support, since a new keymap might be loaded at some later point. So,
we set all keybit in the input device.

The uevent for the input device includes all the key codes, of which
there are now 768. This overflows the size of the uevent
(UEVENT_BUFFER_SIZE) and no event is generated.

Revert for now until we figure out a different solution.

This reverts commit fec225a04330d0f222d24feb5bea045526031675.

Cc: <stable@...r.kernel.org> # 4.20+
Reported-by: Christian Holpert <christian@...pert.de>
Signed-off-by: Sean Young <sean@...s.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@...nel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@...uxfoundation.org>

---
 drivers/media/rc/rc-main.c |   13 ++++++++++++-
 1 file changed, 12 insertions(+), 1 deletion(-)

--- a/drivers/media/rc/rc-main.c
+++ b/drivers/media/rc/rc-main.c
@@ -274,6 +274,7 @@ static unsigned int ir_update_mapping(st
 				      unsigned int new_keycode)
 {
 	int old_keycode = rc_map->scan[index].keycode;
+	int i;
 
 	/* Did the user wish to remove the mapping? */
 	if (new_keycode == KEY_RESERVED || new_keycode == KEY_UNKNOWN) {
@@ -288,9 +289,20 @@ static unsigned int ir_update_mapping(st
 			old_keycode == KEY_RESERVED ? "New" : "Replacing",
 			rc_map->scan[index].scancode, new_keycode);
 		rc_map->scan[index].keycode = new_keycode;
+		__set_bit(new_keycode, dev->input_dev->keybit);
 	}
 
 	if (old_keycode != KEY_RESERVED) {
+		/* A previous mapping was updated... */
+		__clear_bit(old_keycode, dev->input_dev->keybit);
+		/* ... but another scancode might use the same keycode */
+		for (i = 0; i < rc_map->len; i++) {
+			if (rc_map->scan[i].keycode == old_keycode) {
+				__set_bit(old_keycode, dev->input_dev->keybit);
+				break;
+			}
+		}
+
 		/* Possibly shrink the keytable, failure is not a problem */
 		ir_resize_table(dev, rc_map, GFP_ATOMIC);
 	}
@@ -1750,7 +1762,6 @@ static int rc_prepare_rx_device(struct r
 	set_bit(EV_REP, dev->input_dev->evbit);
 	set_bit(EV_MSC, dev->input_dev->evbit);
 	set_bit(MSC_SCAN, dev->input_dev->mscbit);
-	bitmap_fill(dev->input_dev->keybit, KEY_CNT);
 
 	/* Pointer/mouse events */
 	set_bit(EV_REL, dev->input_dev->evbit);